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1

XT-ADS Windowless spallation target thermohydraulic design & experimental setup  

NASA Astrophysics Data System (ADS)

The objective of the European 6th framework Integrated Project (IP) EUROTRANS (EUROpean Research Programme for the TRANSmutation of High Level Nuclear Waste in an Accelerator Driven System) is to demonstrate the feasibility of transmutation of high level nuclear waste using subcritical Accelerator Driven Systems (ADS). The spallation target represents the most challenging new component in an ADS since it is the component coupling the accelerator and the nuclear core and is subjected to very high thermal load in a high radiation field. In this document the thermal hydraulic activities which led to reliable design rules for a windowless target are presented and the status of the heavy liquid metal target mock-up experiment at the KArlsruhe Liquid metal LAboratory (KALLA) are reported.

Class, A. G.; Angeli, D.; Batta, A.; Dierckx, M.; Fellmoser, F.; Moreau, V.; Roelofs, F.; Schuurmans, P.; van Tichelen, K.; Wetzel, T.

2011-08-01

2

Automated Core Design  

SciTech Connect

Multistate searching methods are a subfield of distributed artificial intelligence that aims to provide both principles for construction of complex systems involving multiple states and mechanisms for coordination of independent agents' actions. This paper proposes a multistate searching algorithm with reinforcement learning for the automatic core design of a boiling water reactor. The characteristics of this algorithm are that the coupling structure and the coupling operation suitable for the assigned problem are assumed and an optimal solution is obtained by mutual interference in multistate transitions using multiagents. Calculations in an actual plant confirmed that the proposed algorithm increased the convergence ability of the optimization process.

Kobayashi, Yoko; Aiyoshi, Eitaro

2005-07-15

3

Design configuration of GCFR core assemblies  

SciTech Connect

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.

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

1980-05-01

4

Identifying the Core in Art and Design.  

ERIC Educational Resources Information Center

|Presents a model for systematizing the relationships between core content and educational objectives in British art and design classes. The model shows how the expressive, perceptual, analytic and cultural domains of art and design education are interrelated. Available from Carfax Publishing Company, P.O. Box 25, Abingdon, Oxfordshire OX14 1RW…

Allison, Brian

1982-01-01

5

Many-core design from a thermal perspective  

Microsoft Academic Search

Air cooling limits have been a major design challenge in recent years for integrated circuits. Multi-core exacerbates thermal chal- lenges because power scales with the number of cores, but also creates new opportunities for temperature-aware design, because multi-core designs offer more design parameters than single-core designs. This paper investigates the relationship between core size and on-chip hot spot temperature and

Wei Huang; Mircea R. Stant; Karthik Sankaranarayanan; Robert J. Ribando; Kevin Skadron

2008-01-01

6

Advanced High Temperature Reactor Neutronic Core Design  

SciTech Connect

The AHTR is a 3400 MW(t) FHR class reactor design concept intended to serve as a central generating station type power plant. While significant technology development and demonstration remains, the basic design concept appears sound and tolerant of much of the remaining performance uncertainty. No fundamental impediments have been identified that would prevent widespread deployment of the concept. This paper focuses on the preliminary neutronic design studies performed at ORNL during the fiscal year 2011. After a brief presentation of the AHTR design concept, the paper summarizes several neutronic studies performed at ORNL during 2011. An optimization study for the AHTR core is first presented. The temperature and void coefficients of reactivity are then analyzed for a few configurations of interest. A discussion of the limiting factors due to the fast neutron fluence follows. The neutronic studies conclude with a discussion of the control and shutdown options. The studies presented confirm that sound neutronic alternatives exist for the design of the AHTR to maintain full passive safety features and reasonable operation conditions.

Ilas, Dan [ORNL; Holcomb, David Eugene [ORNL; Varma, Venugopal Koikal [ORNL

2012-01-01

7

Core bit design reduces mud invasion, improves ROP  

SciTech Connect

A recently developed core bit reduces fluid invasion in the cut core by minimizing the exposure to the drilling fluid and by increasing the rate of penetration (ROP). A high ROP during coring is one of the major factors in reducing mud filtrate invasion in cores. This new low-invasion polycrystalline diamond compact (PDC) core bit was designed to achieve a higher ROP than conventional PDC core bits without detriment to the cutting structure. The paper describes the bit and its operation, results of lab tests, fluid dynamics, and results of field tests.

Clydesdale, G. (Security DBS, Aberdeen (United Kingdom)); Leseultre, A.; Lamine, E. (Security DBS, Brussels (Belgium))

1994-08-08

8

Basic criticality relations for gas core design  

SciTech Connect

Minimum critical fissile concentrations are calculated for U-233, U-235, Pu-239, and Am-242m mixed homogeneously with hydrogen at temperatures to 15,000K. Minimum critical masses of the same mixtures in a 1000 liter sphere are also calculated. It is shown that propellent efficiencies of a gas core fizzler engine using Am-242m as fuel would exceed those in a solid core engine as small as 1000L operating at 100 atmospheres pressure. The same would be true for Pu-239 and possibly U-233 at pressures of 1000 atm. or at larger volumes.

Tanner, J.E.

1992-05-22

9

Novel kind of DSP design method based on IP core  

Microsoft Academic Search

With the pressure from the design productivity and various special applications, original design method for DSP can no longer keep up with the required speed. A novel design method is needed urgently. Intellectual Property (IP) reusing is a tendency for DSP design, but simple plug-and-play IP cores approaches almost never work. Therefore, appropriate control strategies are needed to connect all

Qiaoyan Yu; Peng Liu; Weidong Wang; Xiang Hong; Jicheng Chen; Jianzhong Yuan; Keming Chen

2004-01-01

10

Design of the Clinch River Breeder Reactor Plant heterogeneous core  

SciTech Connect

The original core design for the Clinch River Breeder Reactor Plant (CRBRP) was a homogeneous core, as are essentially all of present day liquid metal fast breeder reactors. A study was undertaken to determine if a rearrangement of the core into a heterogeneous configuration, with fertile elements interspersed within the fueled zone, would improve the breeding ratio significantly without excessive adverse effects on other aspects of the design. The result of the study was that the heterogeneous concept improved not only the breeding ratio and doubling time, but also the control assembly worth, core restraint response, and the fuel cycle cost. This paper describes the design evolution and the major effects of the change from a homogeneous to a heterogeneous core in the Clinch River Breeder Reactor Plant.

Dickson, P.W. Jr.; Arnold, W.H.

1982-01-01

11

Designing systems-on-chip using cores  

Microsoft Academic Search

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

Reinaldo A. Bergamaschi; William R. Lee

2000-01-01

12

The Encapsulated Nuclear Heat Source (ENHS) Reactor Core Design  

SciTech Connect

A once-for-life, uniform composition, blanket-free and fuel-shuffling-free reference core has been designed for the Encapsulated Nuclear Heat Source (ENHS) to provide the design goals of a nearly zero burnup reactivity swing throughout {approx}20 yr of full-power operation up to the peak discharge burnup of more than 100 GWd/t HM. What limits the core life is radiation damage to the HT-9 structural material. The temperature coefficients of reactivity are all negative, except for that of the coolant expansion. However, the negative reactivity coefficient associated with the radial expansion of the core structure can compensate for the coolant thermal expansion. The void coefficient is positive but of no safety concern because the boiling temperature of lead or lead-bismuth is so high that there is no conceivable mechanism for the introduction of significant void fraction into the core. The core reactivity coefficients, reactivity worth, and power distributions are almost constant throughout the core life.It was found possible to design such once-for-life cores using different qualities of Pu and transuranics as long as U is used as the primary fertile material. It is also feasible to design ENHS cores using nitride rather than metallic fuel. Relative to the reference metallic fuel core, nitride fuel cores offer up to {approx}25% higher discharge burnup and longer life, up to {approx}38% more energy per core, a significantly more negative Doppler reactivity coefficient, and less positive coolant expansion and coolant void reactivity coefficient but a somewhat smaller negative fuel expansion reactivity coefficient. The pitch-to-diameter ratio (1.45 of the nitride fuel cores using enriched N) is larger than that (1.36) for the reference metallic fuel core, implying a reduction of the coolant friction loss, thus enabling an increase in the power level that can be removed from the core by natural circulation cooling.It is also possible to design Pu-U(10Zr) fueled ENHS-type cores using Na as the primary coolant with either Na or Pb-Bi secondary coolants. The Na-cooled cores feature a tighter lattice and are therefore more compact but have spikier power distribution, more positive coolant temperature reactivity coefficients, and smaller reactivity worth of the control elements.

Hong, Ser Gi [Korea Atomic Energy Research Institute (Korea, Republic of); Greenspan, Ehud [University of California, Berkeley (United States); Kim, Yeong Il [Korea Atomic Energy Research Institute (Korea, Republic of)

2005-01-15

13

Preliminary engineering design of sodium-cooled CANDLE core  

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

14

Fuel and Core Design Experiences in Cofrentes NPP  

SciTech Connect

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)

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

2002-07-01

15

The Encapsulated Nuclear Heat Source (ENHS) Reactor Core Design  

Microsoft Academic Search

A once-for-life, uniform composition, blanket-free and fuel-shuffling-free reference core has been designed for the Encapsulated Nuclear Heat Source (ENHS) to provide the design goals of a nearly zero burnup reactivity swing throughout â20 yr of full-power operation up to the peak discharge burnup of more than 100 GWd\\/t HM. What limits the core life is radiation damage to the HT-9

Ser Gi Hong; Ehud Greenspan; Yeong Il Kim

2005-01-01

16

De novo design of the hydrophobic core of ubiquitin.  

PubMed Central

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.

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

1997-01-01

17

Optimum design of single core shear walls  

Microsoft Academic Search

Design of reinforced concrete thin walled open sections subjected to combined loading such as axial force, biaxial bending moment and torsional moment is cumbersome. This is due to the fact that such structures possess very little torsional rigidity and the plane cross section does not remain plane after the deformation. In this study, an algorithm is developed for the optimum

S. S. Al-Mosawi; M. P. Saka

1999-01-01

18

Design of a RISC Microcontroller Core in 48 Hours  

Microsoft Academic Search

In this paper we present a design case study using Handel-C—a recently developed programming language for compilation of high-level programs directly into FPGA hardware. The design is an 8-bit RISC microcontroller core with 33 instructions, prescaler and a programmable timer. Handel-C was used throughout the entire design and debugging flow. The RISC microcontroller design was implemented in on the XESS

D. ulÍk; M. Vasilko; P. Fuchs

19

Nuclear data for Non-refueling core design  

Microsoft Academic Search

For design of innovative control system and safety characteristic of the Non-refueling core design of long life, a series of critical experiments is conducted at the fast critical facility, FCA of JAEA-Tokai. To quantitatively estimate the uncertainty reduction through critical experiments, an uncertainty reduction ratio (UR) is introduced, using the cross section error. Additionally with sensitivity analysis of the cross

Tetsuo MATSUMURA; Yasushi NAUCHI; Nobuyuki UEDA; Shigeaki OKAJIMA; Toshikazu TAKEDA

20

Development of structural design criteria for highly irradiated core components  

Microsoft Academic Search

This paper reviews development to date in the US of structural design criteria for fast breeder reactor core components. Since these components operate in an elevated temperature, fast neutron environment, the criteria for them must take into account the significant time-dependent changes in structural material behavior resulting from irradiation. Objective is to establish a national consensus on design rules, together

D. V. Nelson; M. M. Abo-El-Ata; J. D. Stephen; R. G. Sim

1978-01-01

21

Hydraulic design and performance of a GCFR core assembly orifice  

Microsoft Academic Search

The design and performance of a core assembly orifice for gas-cooled fast-breeder reactors (GCFRs) are studied in this report. Successful reactor operation relies on adequate cooling, among other things, and orificing is important to cooling. A simple, yet effective, graphical design method for estimating the loss coefficient of an orifice and its associated opening area is presented. A numerical example

1980-01-01

22

A Tight Lattice, Epithermal Core Design for the Integral PWR  

SciTech Connect

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)

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

23

Resistance to torsional forces of various post and core designs.  

PubMed

This in vitro study investigated the resistance of various post and core designs to torsional forces. Cast gold, parallel-sided, serrated post and cores were cemented in extracted teeth. The test groups were made up of the following designs: controls without an antirotational feature, keyway form, coronal flare form, auxiliary pin form, a cervical collar form, and included a tapered post group. The specimens were mounted on an Instron Universal testing machine and a torsional force was applied to the core using a lever arm until failure. All the antirotational features tested elevated resistance to torque. Failure occurred through fracture of the tooth, the cement, or an optional auxiliary pin. The cervical collar was the most favorable design, embracing resistance and reducing tooth fractures. PMID:1800728

Hemmings, K W; King, P A; Setchell, D J

1991-09-01

24

Comparative safety assessment of upflow versus downflow GCFR core designs  

SciTech Connect

This report presents a hypothetical core disruptive accident safety assessment and a post-accident fuel containment evaluation which were performed for the upflow versus downflow core design decision for the GCFR. Differences between the upflow and downflow unprotected accident sequences were not significant. However, differences do appear when potential accident mitigation and recriticality prevention design concepts are investigated for the loss of shutdown cooling and flow blockage accidents. An in-vessel molten fuel containment system is preferred over an ex-vessel system for both the upflow and downflow concepts.

Frank, M.V.; Kang, C.S.; Reilly, J.T.; Wheeler, P.A.

1980-09-01

25

Conceptual study of advanced PWR core design. Development of advanced PWR core neutronics analysis system.  

National Technical Information Service (NTIS)

The neutronics design system of the advanced PWR consists of (i) hexagonal cell and fuel assembly code for generation of homogenized few-group cross sections and (ii) global core neutronics analysis code for computations of steady-state pin-wise or assemb...

C. H. Kim S. C. Kim T. K. Kim J. Y. Cho H. C. Lee

1995-01-01

26

Two stochastic optimization algorithms applied to nuclear reactor core design  

Microsoft Academic Search

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

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

2006-01-01

27

Design Studies on Iron-Core Synchronously Operating Linear Motors.  

National Technical Information Service (NTIS)

This report concerns the design of iron-core synchronously-operating linear motors with passive rail track. Claw-pole and homopolar inductor motors were the 2 basic types considered. The principal conclusions were the homopolar inductor motor is the prefe...

E. Levi

1981-01-01

28

Hydraulic Design and Performance of a GCFR Core Assembly Orifice.  

National Technical Information Service (NTIS)

The design and performance of a core assembly orifice for gas-cooled fast-breeder reactors (GCFRs) are studied in this report. Successful reactor operation relies on adequate cooling, among other things, and orificing is important to cooling. A simple, ye...

I. M. Tang

1980-01-01

29

Design and analysis of PCRV core cavity closure  

SciTech Connect

Design requirements and considerations for a core cavity closure which led to the choice of a concrete closure with a toggle hold-down as the design for the Gas-Cooled Fast Breeder Reactor (GCFR) plant are discussed. A procedure for preliminary stress analysis of the closure by means of a three-dimensional finite element method is described. A limited parametric study using this procedure indicates the adequacy of the present closure design and the significance of radial compression developed as a result of inclined support reaction.

Lee, T.T.; Schwartz, A.A.; Koopman, D.C.A.

1980-05-01

30

The mandibular incisor: rethinking guidelines for post and core design.  

PubMed

In post and core research, little attention has been given to the tooth with minimal bulk and mesialdistal width. The purpose of this in vitro study was to investigate retention and fracture characteristics of lower incisors restored with variable dowel designs. Fifty freshly extracted mandibular incisors were endodontically treated. Four groups of 10 teeth, decoronalized and dowel- and core-restored, were tested for retention characteristics and fracture resistance. One group of 10 teeth restored with composite resin in intact natural crown acted as controls. Dowel variables included a prefabricated round cross-sectional design and a morphologic dowel that reproduced the canal space. A universal testing machine created tensile and transverse loads, and failure was measured and recorded. Results showed no difference in resistance to transverse loading between morphological and standardized dowels (p > 0.05). However, when analyzing modes of failure, ferruled morphological post and core design was less likely to result in a catastrophic root or post fracture. In addition, morphological dowels were significantly more retentive than standardized round dowels in teeth with narrow cross-sections (p = 0.007). This study also reaffirmed the findings of previous investigations, that the intact natural crown of an endodontically treated tooth provides maximum resistance to root fracture. PMID:7714432

Gluskin, A H; Radke, R A; Frost, S L; Watanabe, L G

1995-01-01

31

System design description for GCFR-core flow test loop  

SciTech Connect

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.

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

1980-12-01

32

Status of axial heterogeneous liquid-metal fast breeder reactor core design studies and research and development  

Microsoft Academic Search

The current status of axial heterogeneous core (AHC) design development in Japan, which consists of an AHC core design in a pool-type demonstration fast breeder reactor (DFBR) and research and development activities supporting AHC core design, is presented. The DFBR core design objectives developed by The Japan Atomic Power Company include (a) favorable core seismic response, (b) core compactness, (c)

H. Nakagawa; T. Inagaki; H. Yoshimi; K. Shirakata; Y. Watari; M. Suzuki; K. Inoue

1988-01-01

33

Core transform design for high-efficiency video coding  

NASA Astrophysics Data System (ADS)

High Efficiency Video Coding (HEVC) is the next generation video coding standard currently being developed by the Joint Collaborative Team on Video Coding (JCT-VC). It employs various coding unit sizes 2K×2K, where K is a positive integer with the typical values from 3 to 6; it also uses larger transform sizes up to 32×32. This raises the interest in seeking high performance higher order integer transforms with low computation requirements. This paper presents approaches to designing order-N (N=4, 8, 16, 32) integer transforms, by which the derived integer transforms have special symmetry structures to ensure the matrix factorization. The proposed set of high order integer transforms with well selected elements demonstrates excellent coding performance, compared with the core transform design in HEVC.

Dong, Jie; Ye, Yan

2012-10-01

34

Energy efficient engine core design and performance report. Report, January 1978-December 1982  

SciTech Connect

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.

Stearns, E.M.

1982-12-01

35

FEM simulations in designing saturated iron core superconducting fault current limiters  

Microsoft Academic Search

Proper design of the iron cores is crucial for a saturated iron core superconducting fault current limiter. An optimized design requires guaranteeing sufficient magnetic saturation on the iron cores holding the AC coils, ensuring the efficiency of current limiting, minimizing the use of materials, as well as satisfying the safety and stability obligations. One of the key tasks in the

J. Z. Wang; W. Z. Gong; Y. Xin; J. Y. Zhang; X. M. Hu; Y. W. Sun; T. Q. Wu; B. Tian; Y. Wang; H. Hong; X. Y. Niu; Q. Li; L. F. Zhang

2009-01-01

36

Improved core design of the high temperature supercritical-pressure light water reactor  

Microsoft Academic Search

A new coolant flow scheme has been devised to raise the average coolant core outlet temperature of the High Temperature Supercritical-Pressure Light Water Reactor (SCLWR-H). A new equilibrium core is designed with this flow scheme to show the feasibility of an SCLWR-H core with an average coolant core outlet temperature of 530°C.In previous studies, the average coolant core outlet temperature

A. Yamaji; K. Kamei; Y. Oka; S. Koshizuka

2005-01-01

37

Design of the Core Support and Restraint Structures for FFTF and CRBRP.  

National Technical Information Service (NTIS)

This paper presents and compares the design and fabrication of the FFTF and CRBRP reactor structures which support and restrain the reactor core assemblies. The fabrication of the core support structure (CSS) for the FFTF reactor was completed October 197...

H. G. Sutton J. A. Rylatt

1977-01-01

38

Core design studies for a 1000 MW{sub th} advanced burner reactor.  

SciTech Connect

This paper describes the core design and performance characteristics of 1000 MW{sub th} Advanced Burner Reactor (ABR) core concepts with a wide range of TRU conversion ratio. Using ternary metal alloy and mixed oxide fuels, reference core designs of a medium TRU conversion ratio of {approx}0.7 were developed by trade-off between burnup reactivity loss and TRU conversion ratio. Based on these reference core concepts, TRU burner cores with low and high TRU conversion ratios were developed by changing the intra-assembly design parameters and core configurations. Reactor performance characteristics were evaluated in detail, including equilibrium cycle core performances, reactivity feedback coefficients, and shutdown margins. The results showed that by employing different assembly designs, a wide range of TRU conversion ratios from {approx}0.2 to break-even can be achieved within the same core without introducing significant performance and safety penalties.

Kim, T. K.; Yang, W. S.; Grandy, C.; Hill, R.; Nuclear Engineering Division

2009-04-01

39

Tokamak Fusion Core Experiment: design studies based on superconducting and hybrid toroidal field coils. Design overview  

SciTech Connect

This document is a design overview that describes the scoping studies and preconceptual design effort performed in FY 1983 on the Tokamak Fusion Core Experiment (TFCX) class of device. These studies focussed on devices with all-superconducting toroidal field (TF) coils and on devices with superconducting TF coils supplemented with copper TF coil inserts located in the bore of the TF coils in the shield region. Each class of device is designed to satisfy the mission of ignition and long pulse equilibrium burn. Typical design parameters are: major radius = 3.75 m, minor radius = 1.0 m, field on axis = 4.5 T, plasma current = 7.0 MA. These designs relay on lower hybrid (LHRH) current rampup and heating to ignition using ion cyclotron range of frequency (ICRF). A pumped limiter has been assumed for impurity control. The present document is a design overview; a more detailed design description is contained in a companion document.

Flanagan, C.A. (ed.)

1984-10-01

40

Nuclear design analysis of a multicavity gas core reactor system  

Microsoft Academic Search

The Innovative Nuclear Space Power Institute (INSPI) at the University of Florida has undertaken extensive research to establish the scientific feasibility and engineering validation of gaseous core reactor and energy conversion systems that have core power densities of a kilowatt per cubic centimeter and reactor masses of a kilogram per thermal megawatt for burstpower space applications. Gaseous core fission concepts

M. M. Panicker; E. T. Dugan; S. Anghaie

1987-01-01

41

Design and fabrication of embedded two elliptical cores hollow fiber  

NASA Astrophysics Data System (ADS)

We propose a novel embedded two elliptical cores fiber with a hollow air hole, and demonstrate the fabrication of the embedded two elliptical cores hollow fiber (EECHF). By using a suspended core-in-tube technique, the fibers are drawn from the preform utilizing a fiber drawing system with a pressure controller. The fiber have a 60?m diameter hollow air hole centrally, a 125?m diameter cladding, two 7.2?m /3.0?m (major axis/minor axis) elliptical cores, and a 3?m thickness silica cladding between core layer and air hole. The EECHF has a great potential for PMFs, high sensitivity in-fiber interferometers, poling fiber and Bio-sensor based on evanescent wave field. The fabrication technology is simple and versatile, and can be easily utilized to fabricate multi-core fiber with any desired aspect ratio elliptical core.

Tian, Fengjun; Yuan, Libo; Dai, Qian; Liu, Zhihai

2011-11-01

42

Design Study of Block-Pin Type Fuel for Experimental VHTR (EVHTR) Core.  

National Technical Information Service (NTIS)

In MARK-II core designs of EVHTR, the minimum Reynolds number in the core is about 2600 and is not satisfactory for the thermal performance. Different cores and fuels have been investigated to improve the thermal characteristics. The following were reveal...

T. Ikushima M. Hirano K. Suzuki T. Kurashige S. Kuroi

1976-01-01

43

Modern sandwich core materials offer new attractive design possibilities  

Microsoft Academic Search

Activities in trying to make the airplane interiors more attractive to passengers increase the demand for complex, three-dimensional sandwich structural parts. The realization of three-dimensional contours often failed in the past, due to a lack of process ability or the enormous production costs caused by the processing of conventional phenolic cores. The new structural foam cores based on thermoplastic polytherimide

Bruno Imhof

1997-01-01

44

Conceptual design of air-core superconducting power transformer for cable transmission system  

Microsoft Academic Search

The air-core superconducting transformer, which has a large magnetizing current, has been proposed as a power transformer that has the function as a shunt reactor. In this paper, the basic design procedure for the air-core superconducting transformer is presented. By using this procedure, 500\\/â(3kV)--66\\/â(3kV)--300 MVA single phase air-core transformer is designed for a model cable transmission system. Then, the performance

Hiroshi Yamaguchi; Yukihiko Sato; Teruo Kataoka

1996-01-01

45

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

Microsoft Academic Search

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

V. Immaneni; S. Raman

1990-01-01

46

Current directions in core-shell nanoparticle design  

Microsoft Academic Search

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,

Wolfgang Schärtl

2010-01-01

47

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

Microsoft Academic Search

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

Ju Wang

2005-01-01

48

Reducing Duration of Refueling Outage by Optimizing Core Design and Shuffling Sequence  

SciTech Connect

Reducing the duration of refueling outage is possible by optimizing the core design and the shuffling sequence. For both options software tools have been developed that have been applied to the three most recent cycles of the Borssele plant in the Netherlands. Applicability of the shuffling sequence optimization to boiling water reactors has been demonstrated by a comparison to a recent shuffle plan used in the Hatch plant located in the United States. Their uses have shown that both core design and shuffling sequence optimization can be exploited to reduce the time needed for reloading a core with an in-core shuffling scheme. Ex-core shuffling schemes for pressurized water reactors can still have substantial benefit from a core design using a minimized number of insert shuffles.

Wakker, P.H.; Verhagen, F.C.M.; Bloois, J.T. van; Sutton, W.R. III

2005-07-15

49

Current directions in core-shell nanoparticle design  

NASA Astrophysics Data System (ADS)

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

Schärtl, Wolfgang

2010-06-01

50

Core Curriculum Analysis: A Tool for Educational Design  

ERIC Educational Resources Information Center

This paper examines the outcome of a dimensional core curriculum analysis. The analysis process was an integral part of an educational development project, which aimed to compact and clarify the curricula of the degree programmes. The task was also in line with the harmonising of the degree structures as part of the Bologna process within higher…

Levander, Lena M.; Mikkola, Minna

2009-01-01

51

Ferrite core loss for power magnetic components design  

Microsoft Academic Search

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

Waseem Roshen

1991-01-01

52

Design of core--shell-type nanoparticles carrying stable radicals in the core.  

PubMed

Utilizing the self-assembled core-shell-type polymeric micelle technique, high-performance nanoparticles possessing stable radicals in the core and reactive groups on the periphery were prepared. The anionic ring-opening polymerization of ethylene oxide (EO) was carried out using potassium 3,3-diethoxypropanolate as an initiator, followed by mesylation with methanesulfonyl chloride to obtain acetal-poly(ethylene glycol)-methanesulfonate (acetal-PEG-Ms; 1). Compound 1 was reacted with potassium O-ethyldithiocarbonate, followed by treatment with n-propylamine to obtain heterobifunctional PEG derivatives containing both sulfanyl and acetal terminal groups (acetal-PEG-SH) (2) in a highly selective and quantitative manner. Poly(ethylene glycol)-block-poly(chloromethylstyrene) (acetal-PEG-b-PCMS) (3) was synthesized by the free-radical telomerization of chloromethylstyrene (CMS) using 2 as a telogen. The chloromethyl groups in the PCMS segment of the block copolymer (3) were quantitatively converted to 2,2,6,6-tetramethylpiperidinyloxys (TEMPOs) via the amination of 3 with 4-amino-TEMPO to obtain acetal-PEG-b-PCMS containing TEMPO moieties (4). The obtained 4 formed core-shell-type nanoparticles in aqueous media when subjected to the dialysis method: the cumulant average diameter of the nanoparticles was about 40 nm, and the nanoparticles emitted intense electron paramagnetic resonance (EPR) signals. The TEMPO radicals in the core of the nanoparticles showed reduction resistance even in the presence of 3.5 mM ascorbic acid. This means that these nanoparticles are anticipated as high-performance bionanoparticles that can be used in vivo. PMID:19191564

Yoshitomi, Toru; Miyamoto, Daisuke; Nagasaki, Yukio

2009-03-01

53

Design review report for rotary mode core sample truck (RMCST) modifications for flammable gas tanks, preliminary design  

SciTech Connect

This report documents the completion of a preliminary design review for the Rotary Mode Core Sample Truck (RMCST) modifications for flammable gas tanks. The RMCST modifications are intended to support core sampling operations in waste tanks requiring flammable gas controls. The objective of this review was to validate basic design assumptions and concepts to support a path forward leading to a final design. The conclusion reached by the review committee was that the design was acceptable and efforts should continue toward a final design review.

Corbett, J.E.

1996-02-01

54

Heterogeneous Multi-core SoC Implementation with System-Level Design Methodology  

Microsoft Academic Search

The trend towards heterogeneous multi-core integration and higher communication bandwidth drastically increases the complexity of the SoC. Architecture design and system validation become extremely challenging. This paper presents a multi-core computing platform which consists of general-purpose microprocessor and dual programmable digital signal processor (DSP) cores for multimedia applications. To demonstrate its outstanding performance and energy efficiency, we develop multimedia and

Jen-Chieh Yeh; Kung-Ming Ji; Shing-Wu Tung; Shau-Yin Tseng

2011-01-01

55

Design of an asynchronous ring bus architecture for multi-core systems  

Microsoft Academic Search

In the multi-core systems, the data transfer between cores becomes a major challenge. An asynchronous ring bus, which is 33 bit width, adopting dual-rail single-track data protocol is proposed in this paper. Owning to asynchronous circuits design, there are different transfer times in different hop counts. For providing higher throughput, multiple cores which are able to access the bus simultaneously

Kai-ming Yang; Kin-fong Lei; Jih-ching Chiu

2010-01-01

56

Iron-core superconducting magnet design and test results for Maglev application  

Microsoft Academic Search

Design and test results are presented for a superconducting electromagnet for levitating and propelling Maglev vehicles at high velocities. A U-shaped iron core carries a superconducting magnet around its back leg and a normal control coil around each leg of the U-core. The open side of the U-core is bridged by an iron rail through a large airgap between the

S. Kalsi; M. Proise; T. Schultheiss; B. Dawkins; K. Herd

1995-01-01

57

Refractory metal component technology for in-core sensor design  

Microsoft Academic Search

Recent advances in refractory metal technology have dramatically extended in the operating range of reactor in-core sensors. Temperatures as high as 2500°C in fuel\\/inert gas have been reliably measured during simulated accident conditions; sensors capable of service to 2200°C in accident water\\/steam environments now appear within reach. The accomplishments reflect an increased understanding of the physical and chemical properties of

1986-01-01

58

Nuclear design of a vapor core reactor for space nuclear propulsion  

Microsoft Academic Search

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

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

1993-01-01

59

Thermal-hydraulic mixing in the split-core ANS reactor design  

Microsoft Academic Search

A design has been proposed for the advanced neutron source (ANS) reactor that incorporates a split core, one purpose of which is to create a mixing plenum between the upper and lower cores. It was hoped that in addition to introducing various desirable neutronics features, such as decreasing the fast neutron flux contamination of thermal and cold neutron beams located

Dorning

1988-01-01

60

2ND Reactor Core of the NS Otto Hahn. Design, Operation Experience, Developments.  

National Technical Information Service (NTIS)

Details of the design of the 2nd reactor core are given, followed by a brief report summarising the operating experience gained with this 2nd core, as well as by an evaluation of measured data and statements concerning the usefulness of the knowledge gain...

H. J. Manthey H. Kracht

1979-01-01

61

Design of saturated iron core superconducting fault current limiter based on numerical calculation  

Microsoft Academic Search

The saturated iron core superconducting fault current limiter (SCFCL) utilizes the non-linear of ferromagnetic hysteresis to change its inductance. Its cores are saturated deeply under normal operation but driven out of saturation whenever fault occurs, so it is very difficult to design this SCFCL through theoretical calculation and there will be biggish error if deal the magnetization curve with subsection

Zhang Xuhong; Zhou Youqing; Zhang Zhifeng

2005-01-01

62

Multipurpose Advanced 'inherently' Safe Reactor (MARS): Core design studies  

SciTech Connect

In the year 2005, in collaboration with CEA, the University of Rome 'La Sapienza' investigated a new core model with the aim at increasing the performances of the reference one, by extending the burn-up to 60 GWD/t in the case of multi-loading strategy and investigating the characteristics and limitations of a 'once-through' option, in order to enhance the proliferation resistance. In the first part of this paper, the objectives of this study and the methods of calculation are briefly described, while in the second part the calculation results are presented. (authors)

Golfier, H. [DM2S/SERMA/LCA, CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Caterino, S. [Univ. of Rome La Sapienza, Dept. of Nuclear Engineering and Energy Conversion, Corso Vittorio Emanuele II, 244 00186 Rome (Italy); Poinot, C.; Delpech, M.; Mignot, G. [DM2S/SERMA/LCA, CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Naviglio, A.; Gandini, A. [Univ. of Rome La Sapienza, Dept. of Nuclear Engineering and Energy Conversion, Corso Vittorio Emanuele II, 244 00186 Rome (Italy)

2006-07-01

63

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

Federal Register 2010, 2011, 2012, 2013

...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,...

2011-03-18

64

Legal Protection on IP Cores for System-on-Chip Designs  

NASA Astrophysics Data System (ADS)

The current semiconductor industry has shifted from vertical integrated model to horizontal specialization model in term of integrated circuit manufacturing. In this circumstance, IP cores as solutions for System-on-Chip (SoC) have become increasingly important for semiconductor business. This paper examines to what extent IP cores of SoC effectively can be protected by current intellectual property system including integrated circuit layout design law, patent law, design law, copyright law and unfair competition prevention act.

Kinoshita, Takahiko

65

Low Power Design for a Multi-core Multi-thread Microprocessor  

Microsoft Academic Search

Power efficiency of microprocessor is essential to green computing. As most microprocessors become multi-core and multi-thread, it's important to study low power design for them. The architecture of MCMT, a multi-core multi-thread microprocessor, is described briefly in this paper. Several low power design techniques, including fine-grained clock gating, instruction throttling and adaptive L2 cache are presented to reduce both the

Wang Yong-Wen; Zheng Qian-Bing; Dou Qiang; Zhang Min-Xuan

2010-01-01

66

Minimum copper and core losses power inductor design  

Microsoft Academic Search

A design procedure which allows for assembling power inductors with minimum overall power loss is given in this paper. The inductor design is carried out by using an iterative procedure where the operating flux density is increased from zero to the saturation value. For any given value of the flux density the winding resulting in the lower AC resistance is

M. Bartoli; A. Reatti; M. K. Kazimierczuk

1996-01-01

67

Design of large-core single-mode Yb3+-doped photonic crystal fiber  

NASA Astrophysics Data System (ADS)

The effective index of the cladding fundamental space-filling mode in photonic crystal fiber (PCF) is simulated by the effective index method. The variation of the effective index with the structure parameters of the fiber is achieved. For the first time, the relations of the V parameter of Yb3+-doped PCF with the refractive index of core and the structure parameters of the fiber are provided. The single-mode characteristics of large-core Yb3+-doped photonic crystal fibers with 7 and 19 missing air holes in the core are analyzed. The large-core single-mode Yb3+-doped photonic crystal fibers with core diameters of 50 ?m, 100 ?m and 150 ?m are designed. The results provide theory instruction for the design and fabrication of fiber.

Zhao, Xing-tao; Zheng, Yi; Liu, Xiao-xu; Zhou, Gui-yao; Liu, Zhaolun; Hou, Lan-tian

2012-05-01

68

Design Core Competence Diagnosis: A Case From the Automotive Industry  

Microsoft Academic Search

1990's have been marked by significant changes both in the strategic management field, with the development of competence-based management and the use of the concept of value-creating network, and in the design management field, with the diffusion of matrix-based tools that help to manage the interdependencies between three domains of design projects: product, process, and organization. Few researchers have helped

Éric Bonjour; Jean-Pierre Micaëlli

2010-01-01

69

Core and Refueling Design Studies for the Advanced High Temperature Reactor  

SciTech Connect

The Advanced High Temperature Reactor (AHTR) is a design concept for a central generating station type [3400 MW(t)] fluoride-salt-cooled high-temperature reactor (FHR). The overall goal of the AHTR development program is to demonstrate the technical feasibility of FHRs as low-cost, large-size power producers while maintaining full passive safety. This report presents the current status of ongoing design studies of the core, in-vessel structures, and refueling options for the AHTR. The AHTR design remains at the notional level of maturity as important material, structural, neutronic, and hydraulic issues remain to be addressed. The present design space exploration, however, indicates that reasonable options exist for the AHTR core, primary heat transport path, and fuel cycle provided that materials and systems technologies develop as anticipated. An illustration of the current AHTR core, reactor vessel, and nearby structures is shown in Fig. ES1. The AHTR core design concept is based upon 252 hexagonal, plate fuel assemblies configured to form a roughly cylindrical core. The core has a fueled height of 5.5 m with 25 cm of reflector above and below the core. The fuel assembly hexagons are {approx}45 cm across the flats. Each fuel assembly contains 18 plates that are 23.9 cm wide and 2.55 cm thick. The reactor vessel has an exterior diameter of 10.48 m and a height of 17.7 m. A row of replaceable graphite reflector prismatic blocks surrounds the core radially. A more complete reactor configuration description is provided in Section 2 of this report. The AHTR core design space exploration was performed under a set of constraints. Only low enrichment (<20%) uranium fuel was considered. The coated particle fuel and matrix materials were derived from those being developed and demonstrated under the Department of Energy Office of Nuclear Energy (DOE-NE) advanced gas reactor program. The coated particle volumetric packing fraction was restricted to at most 40%. The pressure drop across the core was restricted to no more than 1.5 atm during normal operation to minimize the upward force on the core. Also, the flow velocity in the core was restricted to 3 m/s to minimize erosion of the fuel plates. Section 3.1.1 of this report discusses the design restrictions in more detail.

Holcomb, David Eugene [ORNL; Ilas, Dan [ORNL; Varma, Venugopal Koikal [ORNL; Cisneros, Anselmo T [ORNL; Kelly, Ryan P [ORNL; Gehin, Jess C [ORNL

2011-09-01

70

Modified Y-TZP Core Design Improves All-ceramic Crown Reliability  

PubMed Central

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.

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

71

MLA fiber injection for a square core fiber optic beam delivery system: design versus prototype results  

NASA Astrophysics Data System (ADS)

The paper details a square core fiber beam delivery design utilizing a unique micro lens array launch method. The paper includes the resulting performance of a prototype created to verify the design and its stability with an emphasis on homogenization as the fiber is articulated.

Lizotte, Todd; Dickey, Fred

2010-07-01

72

Development of finite element design simulation tool for proximity sensor coils with ferrite cores  

Microsoft Academic Search

In the development of inductive proximity sensors, a great deal of time and effort is spent in the design of the sensor coil, which is typically used with a ferrite core for increased Q (Quality factor). Computer simulation of the sensor coil could shorten this design process by eliminating the need for extensive building and testing of prototypes. Analytical solutions

Frederick W. Hintz; James P. Bobis

1997-01-01

73

Using Analytical Models to Efficiently Explore Hardware Transactional Memory and Multi-Core Co-Design  

Microsoft Academic Search

Transactional memory is emerging as a parallel programming paradigm for multi-core processors. Despite the recent interest in transactional memory, there has been no study to characterize the interaction between hardware transactional memory (HTM) design dimensions and multi-core microarchitecture configuration. In this paper, we investigate the use of analytical modeling techniques to build application-specific performance models for understanding the interaction between

James Poe; Chang-burm Cho; Tao Li

2008-01-01

74

Cyclic fatigue testing of five endodontic post designs supported by four core materials  

Microsoft Academic Search

Purpose. This pilot study examined the cyclic fatigue of five endodontic post systems (AccessPost, Flexi-Flange, Flexi-Post, ParaPost, and Vlock) with four core materials (Tytin silver amalgam, Ti-Core, Ketac-Silver and G-C Miracle Mix).Material and methods. In vitro cyclic fatigue was performed with a machine designed to simulate masticatory fatigue forces. An instantaneous force of 22.2 N (5 pounds) was applied to

Brett I. Cohen; Mark K. Pagnillo; Ira Newman; Barry Lee Musikant; Allan S. Deutsch

1997-01-01

75

Design of coupled power inductors with crossed anisotropy magnetic core for integrated power conversion  

Microsoft Academic Search

Design and partial microfabrication of a coupled power inductor is presented for use in high power-density integrated voltage regulators (IVR). The proposed inductor uses many laminations of uniaxial, high-permeability magnetic material where the orientation of anisotropy between successive laminations is rotated to provide an effectively isotropic core. The high permeability core allows for an inductance density of 200nH\\/mm2, while coupling

Noah Sturcken; Ryan Davies; Cheng Cheng; William E. Bailey; Kenneth L. Shepard

2012-01-01

76

Design and realization of the IP control core in field controllers for LAMOST spectroscopes  

NASA Astrophysics Data System (ADS)

The China-made telescope, LAMOST, consists of 16 spectroscopes to detect stellar spectra via 4000 optical fibers. In each spectroscope, many movable parts work in phase. Those parts are real-time controlled and managed by field controllers based on FPGA. This paper mainly introduces how to use DSP Builder module library in MATLAB / Simulink to construct the IP control core on FPGA chip. This method can also be used to design the control core of PID arithmetic, to carry out arithmetic simulation and generate VHDL language file, as well as to integrate it into SOPC developing environment so as to repeatedly use. In this way, the design period of the control system may be shortened and design process simplified. Finally due to the reversibility and programmability of the IP control core ,a system on a chip for field controllers of spectroscope is realized, which meets astronomical control requirements, providing an effective scheme for embedded system in astronomical instrument applications.

Wang, Jianing; Han, Zhongyi; Zeng, Yizhong; Dai, Songxin; Hu, Zhongwen; Zhu, Yongtian; Wang, Lei; Hou, Yonghui

2010-07-01

77

Optimizing a three-element core design for the Advanced Neutron Source Reactor  

SciTech Connect

Source of neutrons in the proposed Advanced Neutron Source facility is a multipurpose research reactor providing 5-10 times the flux, for neutron beams, of the best existing facilities. Baseline design for the reactor core, based on the ``no new inventions`` rule, was an assembly of two annular fuel elements similar to those used in the Oak Ridge and Grenoble high flux reactors, containing highly enriched U silicide particles. DOE commissioned a study of the use of medium- or low-enriched U; a three-element core design was studied as a means to provide extra volume to accommodate the additional U compound required when the fissionable {sup 235}U has to be diluted with {sup 238}U to reduce the enrichment. This paper describes the design and optimization of that three-element core.

West, C.D.

1995-12-31

78

Implementation of knowledge-based system for iron core inductor design  

Microsoft Academic Search

We describe the implementation of a knowledge-based system for designing iron core inductors. We identify the underlying issues related to the implementation of such a system. We employ a recursive design methodology based on imitating an expert human designer that is suitable for embedding in the knowledge-based system. A hybrid knowledge base, using both frame-based and rule-based paradigms, together with

A. Sadeghian; J. D. Lavers

2004-01-01

79

Design criteria for a self-actuated shutdown system to ensure limitation of core damage. [LMFBR  

SciTech Connect

Safety-based functional requirements and design criteria for a self-actuated shutdown system (SASS) are derived in accordance with LOA-2 success criteria and reliability goals. The design basis transients have been defined and evaluated for the CDS Phase II design, which is a 2550 MWt mixed oxide heterogeneous core reactor. A partial set of reactor responses for selected transients is provided as a function of SASS characteristics such as reactivity worth, trip points, and insertion times.

Deane, N.A.; Atcheson, D.B.

1981-09-01

80

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

SciTech Connect

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)

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

2012-07-01

81

Flux distribution and core loss calculation for single phase and five limb three phase transformer core designs  

Microsoft Academic Search

This paper presents results of an analytical core loss calculation method developed for single phase and five limb three phase core types. Shown are calculation results of flux distributions, flux density waveshapes, spatial flux density curves and loss distributions in cores other than the 3 phase-3 limb core. The analytical results show that the flux distribution is essentially uniform in

E. G. teNyenhuis; G. F. Mechler; R. S. Girgis

2000-01-01

82

Design and Performance of South Ukraine Nuclear Power Plant Mixed Cores  

SciTech Connect

In 2010, 42 Westinghouse fuel assemblies (WFAs) were loaded into the core of South Ukraine Nuclear Power Plant (SUNPP) Unit 3 after four successful cycles with 6 Westinghouse Lead Test Assemblies. The scope of safety substantiating documents required for the regulatory approval of this mixed core was extended considerably, particularly with development and implementation of new methodologies and 3-D kinetic codes. Additional verification for all employed codes was also performed. Despite the inherent hydraulic non-uniformity of a mixed core, it was possible to demonstrate that all design and operating restrictions for three different types of fuel (TVS-M, TVSA and WFA) loaded in the core were conservatively met. This paper provides the main results from the first year of operation of the core loaded with 42 WFAs, the predicted parameters for the transition and equilibrium cycles with WFAs, comparisons of predicted versus measured core parameters, as well as the acceptable margin evaluation results for reactivity accidents using the 3-D kinetic codes. To date WFA design parameters have been confirmed by operation experience.

Abdullayev, A. M.; Baydulin, V.; Zhukov, A. I.; Latorre, Richard

2011-09-24

83

The design and performance of IceCube DeepCore  

NASA Astrophysics Data System (ADS)

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.

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

84

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

NASA Astrophysics Data System (ADS)

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.

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

85

Designing with advanced composites; Report on the European Core Conference, 1st, Zurich, Switzerland, Oct. 20, 21, 1988, Conference Papers  

SciTech Connect

The present conference discusses the development history of sandwich panel construction, production methods and quality assurance for Nomex sandwich panel core papers, the manufacture of honeycomb cores, state-of-the-art design methods for honeycomb-core panels, the Airbus A320 airliner's CFRP rudder structure, and the design tradeoffs encountered in honeycomb-core structures' design. Also discussed are sandwich-construction aircraft cabin interiors meeting new FAA regulations, the use of Nomex honeycomb cores in composite structures, a low-cost manufacturing technique for sandwich structures, and the Starship sandwich panel-incorporating airframe primary structure.

Not Available

1988-01-01

86

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

SciTech Connect

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.

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

1997-05-01

87

Advanced BWR core component designs and the implications for SFD analysis  

SciTech Connect

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.

Ott, L.J.

1997-02-01

88

What makes a protein a protein? Hydrophobic core designs that specify stability and structural properties.  

PubMed Central

Here we describe how the systematic redesign of a protein's hydrophobic core alters its structure and stability. We have repacked the hydrophobic core of the four-helix-bundle protein, Rop, with altered packing patterns and various side chain shapes and sizes. Several designs reproduce the structure and native-like properties of the wild-type, while increasing the thermal stability. Other designs, either with similar sizes but different shapes, or with decreased sizes of the packing residues, destabilize the protein. Finally, overpacking the core with the larger side chains causes a loss of native-like structure. These results allow us to further define the roles of tight residue packing and the burial of hydrophobic surface area in the construction of native-like proteins.

Munson, M.; Balasubramanian, S.; Fleming, K. G.; Nagi, A. D.; O'Brien, R.; Sturtevant, J. M.; Regan, L.

1996-01-01

89

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

Microsoft Academic Search

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

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

2003-01-01

90

Active Learning: Effects of Core Training Design Elements on Self-Regulatory Processes, Learning, and Adaptability  

Microsoft Academic Search

This research describes a comprehensive examination of the cognitive, motivational, and emotional processes underlying active learning approaches, their effects on learning and transfer, and the core training design elements (exploration, training frame, emotion-control) and individual differences (cognitive ability, trait goal orientation, trait anxiety) that shape these processes. Participants (N = 350) were trained to operate a complex computer-based simulation. Exploratory

Bradford S. Bell; Steve W. J. Kozlowski

2008-01-01

91

Design of a Nuclear Magnetic Resonance Fast Field Cycling Air Cored Magnet  

Microsoft Academic Search

A method for the design of a nuclear magnetic resonance fast field cycling air-cored magnet is presented in this paper. General analytic expressions relating the geometric parameters of the magnet with the flux density, the current density and the power losses were obtained. An optimization algorithm based on the thin circular loop coil model to determine the positions of the

Duarte M. Sousa; G. D. Marques; P. J. Sebastiao; A. C. Ribeiro

2007-01-01

92

Design of the Core Elements of the Digital Avionics Information System, Volume III.  

National Technical Information Service (NTIS)

This final technical report presents the design of the Core Elements of Digital Avionics Information System (DAIS). The report is in 10 sections, one for each of the major tasks defined in the contract statement of work. The report is divided into three v...

J. Early J. Hinderer L. A. Chamberlin T. Falconer V. Gylys

1974-01-01

93

Design of the Core Elements of the Digital Avionics Information System, Volume II.  

National Technical Information Service (NTIS)

This final technical report presents the design of the Core Elements of Digital Avionics Information System (DAIS). The report is in 10 sections, one for each of the major tasks defined in the contract statement of work. The report is divided into three v...

J. Early J. Hinderer L. A. Chamberlin T. Falconer V. Gylys

1974-01-01

94

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

Microsoft Academic Search

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

Joep Aerts; Erik Jan Marinissen

1998-01-01

95

Spring design for use in the core of a nuclear reactor  

DOEpatents

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.

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

1993-01-01

96

An in vitro investigation of cast post and partial core design  

Microsoft Academic Search

Objectives: Following endodontic therapy, the provision of a cast post and core restoration may be indicated. Many authors advocate retaining sound coronal dentine where possible, improving the resistance to fracture of the endodontically treated tooth. However, there is little conclusive experimental evidence to support this recommendation. This laboratory study was designed to investigate the effect of retained sound coronal dentine

A. Patel; D. L. Gutteridge

1996-01-01

97

Optimized core design and fuel management of a pebble-bed type nuclear reactor  

Microsoft Academic Search

The core design of a pebble-bed type Very High Temperature Reactor (VHTR) is optimized, aiming for an increase of the coolant outlet temperature to 1000 C, while retaining its inherent safety features. The VHTR has been selected by the international Generation IV research initiative as one of the six most promising nuclear reactor concepts that are expected to enter service

B. Boer

2009-01-01

98

Enabling Programmers to Design Efficient Parallel Algorithms for Many-Core Processors  

Microsoft Academic Search

Since the inception of the desktop computer, performance of software has improved at an exponential rate, primarily driven by the steady technological improvements of microprocessors. Due to fundamental physical limitations and power constraints, we are now witnessing a radical change in commodity microprocessor architecture, to multi-core designs. Continued performance now requires the exploitation of concurrency at the algorithmic level. Automatic

David A. Bader

99

A design of ultrasonic compaction tools for metal powder magnetic core of motors  

Microsoft Academic Search

This report presents the metal powder compaction using ultrasonic vibration for the fabrication of a three-dimensionally-shaped magnetic core. First, we describe a design of ultrasonic compaction tools using FEM. Side wall of the sample was ultrasonically excited by a radial vibration of the die, while the upper and lower punches are driven by longitudinal vibrations. Second, we present the results

Shinichi Kikuchi; Daisuke Koyama; Kentaro Nakamura

2008-01-01

100

A Model Checking Approach for Multi-core Time Partitions Design  

Microsoft Academic Search

In many areas of safety-critical applications multiple applications must execute on a common machine without disturbing each other. Thus spatial and temporal isolation of each application must be guaranteed. In this paper we address the temporal isolation aspect which can be tackled using time partitioning. We propose a technique for automated design of multi-core time partitions based on characteristics of

Georgiana Macariu

2010-01-01

101

Game design principles for engaging cooperative play: core mechanics and interfaces for non-mimetic simulation of fire emergency response  

Microsoft Academic Search

Core mechanics are the activities that players repeat to play a game, the central aspects of play constrained by rules. Interfaces mediate play experiences, impacting engagement with core mechanics. We design core mechanics for gathering, integrating, and sharing information, based on team coordination practices of fire emergency responders. We connect these mechanics with interfaces that impact player engagement. Mechanics and

Zachary O. Toups; Andruid Kerne; William Hamilton

2009-01-01

102

Design solutions to minimize iron core loss in synchronous reluctance motor using Preisach model and FEM  

Microsoft Academic Search

This paper deals with an automatic design procedure for the minimization of iron core loss in a synchronous reluctance motor (SynRM). The focus of this paper is the design relative to hysteresis loss on the basis of rotor shape of a SynRM in the same torque density. The coupled finite-element analysis and Preisach model have been used to evaluate the

Jung Ho Lee

2002-01-01

103

Optimizing a three-element core design for the advanced neutron source reactor  

SciTech Connect

The source of neutrons in the proposed Advanced Neutron Source facility is a multipurpose research reactor providing 5 to 10 times the flux, for neutron beams, of the best existing facilities. The project team constrained the design with the {open_quotes}no new inventions rule,{close_quotes} which states that the design should not rely on the development of new technology to meet the minimum design criteria (although research and development that can lead to further major improvements beyond the minimum requirements is encouraged). The baseline design for the reactor core, based on this objective and within this constraint, was an assembly of two annular fuel elements, similar to those used in the high-flux reactors at Oak Ridge and Grenoble, containing highly enriched (93%) uranium silicide particles. Subsequently, the U.S. Department of Energy commissioned a study of the impact on performance and on cost of using medium - or low-enriched uranium. In the course of that work, a three-element core design was studied as a means to provide extra volume to accommodate the additional uranium compound required when the fissionable {sup 235}U has to be diluted with {sup 238}U to reduce the enrichment. This paper describes the design and optimization of that three-element core.

West, C.D. [Martin Marietta Energy System, Oak Ridge, TN (United States)

1995-12-31

104

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

Microsoft Academic Search

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

Indradeep Ghosh; Niraj K. Jha; Sujit Dey

1999-01-01

105

Constraints on the design of core-shell resonators of locally resonant acoustic metamaterials  

NASA Astrophysics Data System (ADS)

We perform a parametric study of the analytic model of Liu [Z. Liu , Phys. Rev. B10.1103/PhysRevB.71.014103 71, 014103 (2005)] describing the mechanical response of a core-shell particle to an acoustic excitation in order to help in selecting the constitutive materials and in designing innovative processes of fabrication of downsized core-shell resonators, which are key constituents of locally resonant acoustic metamaterials. We show that the value of the first Lamé coefficient of the material constituting the shell has no marked influence on the value of the resonance frequency of the core-shell resonator, that is, it does not necessarily need to be small for satisfying the condition of subwavelength resonator dimension at resonance. Moreover, we show that the larger the density contrast between the core and the shell and the thinner the shell, the broader is the frequency band over which the effective density of the resonator suspension is negative, but that it is practically useless to decrease the dimensionless shell thickness below 0.6. Finally, we show that the dissipation is also less perceptible the thinner is the shell and the larger is the density contrast. The effect of the density contrast between the core and the shell and of the dissipation on the resonance width are explained by comparing with the harmonic oscillator and the mass-in-mass 1D lattice.

Bos, Lionel; Lukyanova, Lyubov; Wunenburger, Régis

2012-11-01

106

Effects of three bonding systems on the torsional resistance of titanium-reinforced composite cores supported by two post designs  

Microsoft Academic Search

Statement of problem. There are no studies that have investigated the effects of bonding agents on the resistance to torque of a composite core supported by a prefabricated post. Purpose. This study investigated the ability of bonding agents to resist rational forces applied to titanium-reinforced composite cores supported by 2 post designs. Material and methods. Two post designs (AccessPost and

Brett I. Cohen; Mark K. Pagnillo; Ira Newman; Barry Lee Musikant; Allan S. Deutsch

1999-01-01

107

Effects of post-core design and ferrule on fracture resistance of endodontically treated maxillary central incisors  

Microsoft Academic Search

Statement of Problem. Studies concerning the effects of post-core design and ferrule on the fracture resistance of endodontically treated teeth remain controversial. Purpose. The purpose of this study was to investigate in vitro the effects of post-core design and ferrule on the fracture resistance of root canal treated human maxillary central incisors restored with metal ceramic crowns. Material and Methods.

Lu Zhi-Yue; Zhang Yu-Xing

2003-01-01

108

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

SciTech Connect

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.

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

1996-02-01

109

Design assumptions and bases for small D-T-fueled spherical tokamak (ST) fusion core  

SciTech Connect

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. 51 refs., 6 figs., 3 tabs.

Peng, Y.K.M. [Oak Ridge National Lab., TN (United States); Cheng, E.T.; Cerbone, R.J. [TSI Research, Inc., Solana Beach, CA (United States)] [and others

1996-12-31

110

Design assumptions and bases for small D-T-fueled spherical tokamak (ST) fusion core  

SciTech Connect

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.

Peng, Yueng Kay Martin [ORNL; Haines, J.R. [Oak Ridge National Laboratory (ORNL)

1996-01-01

111

Hardware-Software Co-design of QRD-RLS Algorithm with Microblaze Soft Core Processor  

NASA Astrophysics Data System (ADS)

This paper presents the implementation of QR Decomposition based Recursive Least Square (QRD-RLS) algorithm on Field Programmable Gate Arrays (FPGA). The design is based on hardware-software co-design. The hardware part consists of a custom peripheral that solves the part of the algorithm with higher computational costs and the software part consists of an embedded soft core processor that manages the control functions and rest of the algorithm. The use of Givens Rotation and Systolic Arrays make this architecture suitable for FPGA implementation. Moreover, the speed and flexibility of FPGAs render them viable for such computationally intensive application. The system has been implemented on Xilinx Spartan 3E FPGA with Microblaze soft core processor using Embedded Development Kit (EDK). The paper also presents the implementation results and their analysis.

Lodha, Nupur; Rai, Nivesh; Dubey, Rahul; Venkataraman, Hrishikesh

112

Design and Calibration of a High-Precision Density Gauge for Firn and Ice Cores  

NASA Astrophysics Data System (ADS)

The Maine Automated Density Gauge Experiment (MADGE) is a field deployable gamma-ray density gauging instrument designed to provide high resolution (3.3 mm) and high precision (±0.004 g cm-3) density profiles of polar firn and ice cores at a typical throughput of 1.5 m h-1. The resulting density profiles are important in ice sheet mass balance and paleoclimate studies, as well as the modeling electromagnetic wave propagation in firn and ice for remote sensing and ground penetrating radar applications. This study describes the design (optimal gamma-ray energy selection, measurement uncertainty analysis, dead-time corrections) and calibration (mass-attenuation coefficient and absolute density calibrations) of the instrument, and discusses the results of additional experiments to verify the calculated measurement uncertainty. Data collected from firn cores drilled on the recent 2006-2007 U.S. Internation Trans-Antarctic Scientific Expedition are also shown and discussed.

Breton, Daniel; Hamilton, Gordon

2009-10-01

113

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

NASA Astrophysics Data System (ADS)

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/(nm.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/(nm.km) in S+C+L band. It can realize the dispersion slope compensation because that it exhibits a negative dispersion slope.

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

2007-11-01

114

Preliminary design report for SCDAP/RELAP5 lower core plate model  

SciTech Connect

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.

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

115

A Microwave Radiometer for Close Proximity Core Body Temperature Monitoring: Design, Development, and Experimentation  

Microsoft Academic Search

Presented is a radiometric sensor and associated electromagnetic propagation models, developed to facilitate non-invasive core body temperature extraction. The system has been designed as a close-proximity sensor to detect thermal emissions radiated from deep-seated tissue 1 cm – 3 cm inside the human body. The sensor is intended for close proximity health monitoring applications, with potential implications for deployment into

Quenton Bonds

2010-01-01

116

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

Microsoft Academic Search

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

Jiabin Wang; David Howe

2004-01-01

117

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

Microsoft Academic Search

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.

Erika Cota; Luigi Carro; Marcelo Lubaszewski; Alex Orailoglu

2002-01-01

118

Conceptual Design Study of 180 MWt Small-Sized Reduced-Moderation Water Reactor Core  

Microsoft Academic Search

Conceptual design of a Small-sized Reduced-Moderation Water Reactor (S-RMWR) core, which has the thermal output of 180 MW, the conversion ratio of 1.0 and the void reactivity coefficient of negative value, has been constructed. S-RMWR is a technology demonstration reactor which also conducts material and fuel testing for commercial use of Reduced-Moderation Water Reactor (RMWR) in large-scale power plants. It

Yoshihiro NAKANO; Tsutomu OKUBO; Sadao UCHIKAWA

2006-01-01

119

General strategy for designing core-shell nanostructured materials for high-power lithium ion batteries.  

PubMed

Because of its extreme safety and outstanding cycle life, Li(4)Ti(5)O(12) has been regarded as one of the most promising anode materials for next-generation high-power lithium-ion batteries. Nevertheless, Li(4)Ti(5)O(12) suffers from poor electronic conductivity. Here, we develop a novel strategy for the fabrication of Li(4)Ti(5)O(12)/carbon core-shell electrodes using metal oxyacetyl acetonate as titania and single-source carbon. Importantly, this novel approach is simple and general, with which we have successfully produce nanosized particles of an olivine-type LiMPO(4) (M = Fe, Mn, and Co) core with a uniform carbon shell, one of the leading cathode materials for lithium-ion batteries. Metal acetylacetonates first decompose with carbon coating the particles, which is followed by a solid state reaction in the limited reaction area inside the carbon shell to produce the LTO/C (LMPO(4)/C) core-shell nanostructure. The optimum design of the core-shell nanostructures permits fast kinetics for both transported Li(+) ions and electrons, enabling high-power performance. PMID:23092272

Shen, Laifa; Li, Hongsen; Uchaker, Evan; Zhang, Xiaogang; Cao, Guozhong

2012-10-25

120

Status of axial heterogeneous liquid-metal fast breeder reactor core design studies and research and development  

SciTech Connect

The current status of axial heterogeneous core (AHC) design development in Japan, which consists of an AHC core design in a pool-type demonstration fast breeder reactor (DFBR) and research and development activities supporting AHC core design, is presented. The DFBR core design objectives developed by The Japan Atomic Power Company include (a) favorable core seismic response, (b) core compactness, (c) high availability, and (d) lower fuel cycle cost. The AHC concept was selected as a reference pool-type DFBR core because it met these objectives more suitably than the homogeneous core (HOC). The AHC core layouts were optimized emphasizing the reduction of the burnup reactivity swing, peak fast fluence, and power peaking. The key performance parameters resulting from the AHC, such as flat axial power/flux distribution, lower peak fast fluence, lower burnup reactivity swing, etc., were evaluated in comparison with the HOC. The critical experiments at the Japan Atomic Energy Research Institute's Fast Critical Assembly facility demonstrate the key AHC performance characteristics. The large AHC engineering benchmark experiments using the zero-power plutonium reactor and the AHC fuel pin irradiation test program using the JOYO reactor are also presented.

Nakagawa, H.; Inagaki, T.; Yoshimi, H.; Shirakata, K.; Watari, Y.; Suzuki, M.; Inoue, K.

1988-11-01

121

Session: ANALOG & ELECTRICAL DESIGN Guidelines for Designing Smart and Reusable Analog IP Cores  

Microsoft Academic Search

Every analog designer has to face with the legacy of the traditional analog development, an iterative con- ception process where a single computation loop can last a week. The tremendous gap between the analog and the digital world's methodology of conception is sharper than ever. The reasons should be found both in the lack of automated tools and in the

P. Nguyen Tuong; M.-M. Louerat; A. Greiner

122

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

SciTech Connect

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.

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

2008-05-05

123

PVDF core-free actuator for Braille displays: design, fabrication process, and testing  

NASA Astrophysics Data System (ADS)

Refreshable Braille displays require many, small diameter actuators to move the pins. The electrostrictive P(VDF-TrFECFE) terpolymer can provide the high strain and actuation force under modest electric fields that are required of this application. In this paper, we develop core-free tubular actuators and integrate them into a 3 × 2 Braille cell. The films are solution cast, stretched to 6 ?m thick, electroded, laminated into a bilayer, rolled into a 2 mm diameter tube, bonded, and provided with top and bottom contacts. Experimental testing of 17 actuators demonstrates significant strains (up to 4%). A novel Braille cell is designed and fabricated using six of these actuators.

Levard, Thomas; Diglio, Paul J.; Lu, Sheng-Guo; Rahn, Christopher D.; Zhang, Q. M.

2011-03-01

124

Fuel performance models for high-temperature gas-cooled reactor core design  

SciTech Connect

Mechanistic fuel performance models are used in high-temperature gas-cooled reactor core design and licensing to predict failure and fission product release. Fuel particles manufactured with defective or missing SiC, IPyC, or fuel dispersion in the buffer fail at a level of less than 5 x 10/sup -4/ fraction. These failed particles primarily release metallic fission products because the OPyC remains intact on 90% of the particles and retains gaseous isotopes. The predicted failure of particles using performance models appears to be conservative relative to operating reactor experience.

Stansfield, O.M.; Simon, W.A.; Baxter, A.M.

1983-09-01

125

Nuclear design of a vapor core reactor for space nuclear propulsion  

NASA Astrophysics Data System (ADS)

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.

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

1993-01-01

126

Analysis of Process Parameters Affecting Spray-Dried Oily Core Nanocapsules Using Factorial Design  

PubMed Central

The purpose of this work was to optimize the process parameters required for the production of spray-dried oily core nanocapsules (NCs) with targeted size and drug yield using a two-level four-factor fractional factorial experimental design (FFED). The coded process parameters chosen were inlet temperature (X1), feed flow rate (X2), atomizing air flow (X3), and aspiration rate (X4). The produced NCs were characterized for size, yield, morphology, and powder flowability by dynamic light scattering, electron microscope, Carr’s index, and Hausner ratio measurement, respectively. The mean size of produced NCs ranged from 129.5 to 444.8 nm, with yield varying from 14.1% to 31.1%. The statistical analysis indicated an adequate model fit in predicting the effect of process parameters affecting yield. Predicted condition for maximum yield was: inlet temperature 140°C, atomizing air flow 600 L/h, feed flow rate 0.18 L/h, and aspiration air flow set at 100%, which led to a yield of 30.8%. The morphological analysis showed the existence of oily core and spherical nanostructure. The results from powder flowability analysis indicated average Carr’s index and Hausner ratio of 42.77% and 1.76, respectively. Spray-dried oily core NCs with size lower than 200 nm were successfully produced, and the FFED proved to be an effective approach in predicting the production of spray-dried NCs of targeted yield.

Zhang, Tao

2010-01-01

127

Calculation of Design Parameters for an Equilibrium LEU Core in the NBSR  

SciTech Connect

A plan is being developed for the conversion of the NIST research reactor (NBSR) from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. Previously, the design of the LEU fuel had been determined in order to provide the users of the NBSR with the same cycle length as exists for the current HEU fueled reactor. The fuel composition at different points within an equilibrium fuel cycle had also been determined. In the present study, neutronics parameters have been calculated for these times in the fuel cycle for both the existing HEU and the proposed LEU equilibrium cores. The results showed differences between the HEU and LEU cores that would not lead to any significant changes in the safety analysis for the converted core. In general the changes were reasonable except that the figure-of-merit for neutrons that can be used by experimentalists shows there will be a 10% reduction in performance. The calculations included kinetics parameters, reactivity coefficients, reactivity worths of control elements and abnormal configurations, and power distributions.

Hanson, A.L.; Diamond, D.

2011-09-30

128

Is it possible to use "twin cores" as a unique sedimentary record? An experimental design based on sediment color  

NASA Astrophysics Data System (ADS)

Sedimentary cores are widely used for studying Quaternary records. However, the amount of sediment that is available is proportional to the diameter of the core, which is rarely bigger than 15 cm. One way to obtain more sediment is to use two cores retrieved from almost the same location and use them as if they represent a unique sedimentary record. In the present work, an experimental design has been applied to verify if "twin cores" from an estuary can be considered as representing the same sedimentary record with twice the amount of sediment to study. Because sediment can be characterized based on its color, the variables used as replicates in the experimental design are the three Lab CIE colors acquired with a X-Rite Colortron spectrophotometer. Sediment cores were retrieved from the upper saltmarsh of Gilão River's estuary, southern Portugal. Twin cores, with in between distances of 50 cm, 100 cm and 200 cm, from two different sites were analysed. Results from a nested ANOVA show that even for the closest twin cores (50 cm apart) there is at least one color variable that shows significant variations between the profiles of both cores. These results clearly show that "twin cores" cannot be used as a unique sedimentary record without any previous testing, at least in such transitional regions.

Veiga-Pires, C.; Mestre, N. C.

2009-01-01

129

Design and preparation of a core-shell metal-organic framework for selective CO2 capture.  

PubMed

The design of a core-shell metal-organic framework comprising a porous bio-MOF-11/14 mixed core and a less porous bio-MOF-14 shell is reported. The growth of the MOF shell was directly observed and supported by SEM and PXRD. The resulting core-shell material exhibits 30% higher CO2 uptake than bio-MOF-14 and low N2 uptake in comparison to the core. When the core-shell architecture is destroyed by fracturing the crystallites via grinding, the amount of N2 adsorbed doubles but the CO2 adsorption capacity remains the same. Finally, the more water stable bio-MOF-14 shell serves to prevent degradation of the water-sensitive core in aqueous environments, as evidenced by SEM and PXRD. PMID:23795996

Li, Tao; Sullivan, Jeanne E; Rosi, Nathaniel L

2013-06-27

130

A power-aware SNR-progressive DCT\\/IDCT IP core design for multimedia transform coding  

Microsoft Academic Search

A power-aware SNR progressive DCT\\/IDCT IP core design for multimedia transform coding is proposed. The proposed IP core possesses the feature of power-aware design flexibility, allowing the trade-off of lower power consumption with less demand of data precision in developing its instruction library. Relationships of energy reduction and data quality degradation in the examples of both JPEG still images and

Kuan-hung Chen; Jiun-in Guo; Jinn-shyan Wang; Ching-wei Yeh

2004-01-01

131

Design and testing of 230 V inductive type of Superconducting Fault Current Limiter with an open core  

Microsoft Academic Search

A single-phase, 230 V Superconducting Fault Current Limiter using two Bi2223 HTS tubes with the total critical current 2.5 kA situated in vacuum insulated cryostat has been described in this paper. We designed and manufactured the inductive SFCL with an open core as core shielded type acquired the optimal design parameters by using Finite Element Method. We tested the limiter

Janusz Kozak; Tadeusz Janowski; Søawomir Kozak; Henryk Malinowski; Grzegorz Wojtasiewicz; Beata Kondratowicz-Kucewicz

2005-01-01

132

Design and fabrication of the iron core for the OHTE experimental machine  

SciTech Connect

The Ohmically Heated Toroidal Experiment (OHTE) is a toroidal pinch magnetic confinement plasma experiment which has been operating at GA Technologies (GA) since February 1981. In its original form, plasma current was induced by an air core induction or ohmic heating coil driven by a capacitor bank. Preliminary study revealed that greater plasma currents and pulse lengths could be achieved more economically by converting to an iron core rather than by installing additional capacitors. Therefore an iron core with a 3 volt-second capability and a stepped configuration was designed, fabricated and incorporated into the OHTE experimental device as part of a planned upgrade. To facilitate handling and installation, the iron core was fabricated in 28 segments consisting of 14 lower and 14 identical upper segments. Space limitations in the center of the machine created by existing geometry limited the flux path to approximately 1.28 m diameter or 1.296 m/sup 2/. Using a stacking factor of 90% and allowing 3 mm between segments results in a true iron cross section of 1.12 m/sup 2/. Each segment was fabricated by continuously winding in a ''clockspring fashion'' around a hardwood former Armco electrically oriented steel, 0.35 mm thick and 88 mm wide. Interspaced between laminations is insulating paper 0.02 mm thick and 88 mm wide bonded to the steel using a structural epoxy adhesive continuously applied during winding. After winding and curing, support saddles consisting of hardwood and aluminum were bonded to the segments. The segments were then cut into two identical halves on a large vertical milling machine. To eliminate electrical shorts, all machined surfaces were etched with a dilute nitric acid solution, then painted with a moisture repelling high dielectric strengt epoxy spray paint to eliminate lamination to lamination creepage and surface corrosion.

Curwen, B.; Franklin, L.H.

1983-09-01

133

77 FR 36611 - Core Principles and Other Requirements for Designated Contract Markets  

Federal Register 2010, 2011, 2012, 2013

...practice for Core Principle 4 provides that DCMs, at a minimum, should have...standard in Core Principle 11 by requiring...to establish minimum financial standards...Amended Core Principle B requires a...that, at a minimum, exceed...

2012-06-19

134

75 FR 80571 - Core Principles and Other Requirements for Designated Contract Markets  

Federal Register 2010, 2011, 2012, 2013

...practice for Core Principle 4 provides that DCMs, at a minimum, should have...requirements of Core Principle 9. The Commission...that setting a minimum percentage of...an acceptable minimum block size. The 2008 Core Principle 9 Proposed...

2010-12-22

135

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

SciTech Connect

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)

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

136

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

Microsoft Academic Search

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

K. Qiu; W. Zhang; P. Duysinx

137

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

SciTech Connect

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

Farmer, M. T .; Nuclear Engineering Division

2009-03-30

138

Design, Synthesis, and Characterization of Bent-Core Mesogen-Jacketed Liquid Crystalline Polymers  

SciTech Connect

We report the design, synthesis, and characterization of a series of mesogen-jacketed liquid crystalline polymers with bent-core liquid crystals (BCLCs). For the first time, BCLC mesogens were directly side-attached to the polymer backbone and bent-core mesogen-jacketed liquid crystalline polymers (BMJLCPs) were achieved. Both three-ring and five-ring mesogens were employed. The n-alkoxy substituent lengths for the three-ring and five-ring BMJLCPs were controlled as n = 1-5 and n = 6-16, respectively. Various characterization techniques such as differential scanning calorimetry, wide-angle X-ray diffraction, and polarized light microscopy were used to study their mesomorphic phase behavior. The monomers of five-ring BMJLCPs with relatively long tails showed mesophase behavior. Columnar liquid crystalline phase was observed in both three-ring and five-ring BMJLCPs. Columnar rectangular ({phi}{sub R}) phase was observed in the three-ring system. In the five-ring BMJLCPs, relatively short-tail homologues possess {phi}{sub R} phase, while columnar hexagonal phase was observed in the long-tail samples. The differences in the phase structures were attributed to the 'softness' of the macromolecular BMJLCP column surface.

Chen,X.; Tenneti, K.; Li, C.; Bai, Y.; Zhou, R.; Wan, X.; Fan, X.; Zhou, Q.

2006-01-01

139

Design Review Report for formal review of safety class features of exhauster system for rotary mode core sampling  

SciTech Connect

Report documenting Formal Design Review conducted on portable exhausters used to support rotary mode core sampling of Hanford underground radioactive waste tanks with focus on Safety Class design features and control requirements for flammable gas environment operation and air discharge permitting compliance.

JANICEK, G.P.

2000-06-08

140

Design, Simulation, and Testing of a Dual Stator-Winding All-Air-Core Compulsator  

Microsoft Academic Search

The focus toward advanced mobile tactical configu- rations for railgun power supplies has resulted in the evolution of five compulsator generations in the past 30 years from iron-core to air-core prototypes. However, the exact air-core field simu- lation and the complicated fabrication technique of an air-core compulsator are not clear enough for researchers. This paper presents a detailed description of

Shaopeng Wu; Shumei Cui; Liwei Song; Weiduo Zhao; Jing Zhang

2011-01-01

141

Design method research into latticed shell tube–reinforced concrete (RC) core wall structures  

Microsoft Academic Search

Latticed shell tube–RC core walls are a new structural system with RC core walls in the center and latticed shell tubing on the outsides. The shear rigidity of RC core wall is big, and the resisting overthrow capability of external latticed shell tubes is powerful. This combination can reduce structural damage that could be caused by seism, and it remarkably

Jinghai Gong; Xinhua Liang

2007-01-01

142

High-performance TF coil design for the Toroidal Fusion Core Experiment (TFCX)  

SciTech Connect

The Toroidal Fusion Core Experiment (TFCX) is a proposed concept for an ignited, long-pulse, current-driven tokamak device. TF coil winding cross section in the inboard region is impacted by peak field 10 T, winding current density approx. 3500 A/cm/sup 2/, and peak nuclear heating rates 50 mW/cc. The winding utilizes a Nb/sub 3/Sn internally cooled cable superconductor (ICCS), which is a modified version of the conductor used in the Westinghouse LCP coil. These modifications include the increase of void fraction from 32% to 41% of the cable space for withstanding higher nuclear heating rates and a thicker conduit wall to carry larger magnetic loads. The critical current of an Nb/sub 3/Sn conductor is strongly dependent on strain in the superconducting strands. The strain in strands is lower when the windings are: (a) wound and then reacted (W/R), as compared to (b) reacted and then wound (R/W). The impact of these approaches on winding performance is discussed. The windings are pancake wound and cooled with supercritical helium. The LHe inlet (approx. 4/sup 0/K) and outlet (approx. 5.5/sup 0/K) connections are located on the sides of the TF coils. The conductor design, the winding design, and performance analysis are described.

Srivastava, V.C.

1984-01-01

143

TCAM core design in 3D IC for low matchline capacitance and low power  

NASA Astrophysics Data System (ADS)

Ternary Content Addressable Memory (TCAM) has been an emerging technology for fast packet forwarding, commonly used in longest prefix match routing. Large table size requirements and wider lookup table data widths have led to higher capacity TCAM designs. However, the fully parallel characteristic of TCAM makes large TCAM design more challenging and limits its capacity due to intensive power consumption. This paper proposes 3D IC technology as a solution to reduce the power consumption by reducing the interconnect capacitances of TCAM. In 3D IC, multiple wafers are stacked on top of each other, and the tiers are vertically connected through 3D vias. 3D vias reduce metal interconnect lengths and parasitic capacitances, resulting in power reduction. In this paper, 3D vias are used to replace matchlines, whose transition during parallel search operations is a major source of high power consumption in TCAM. An analysis of parasitic interconnect capacitance has been done using a quasi-static electromagnetic field simulation tool, Ansoft's Q3D Extractor, on a TCAM memory core in both conventional 2D IC structure and 3D IC structure with the process parameters of the MIT Lincoln Labs 0.18µm FDSOI process. Field analysis and spice simulation results using a capacitance model for interconnects show that a 40% matchline capacitance reduction and a 23% power reduction can be achieved by using a 3-tier 3D IC structure instead of the conventional 2D approach.

Oh, Eun Chu; Franzon, Paul D.

2007-01-01

144

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

Microsoft Academic Search

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

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

2004-01-01

145

Integrated Test Data Decompression and Core Wrapper Design for Low-Cost System-on-a-Chip Testing  

Microsoft Academic Search

This paper discusses an integrated solution for reduc- ing the volume of test data for deterministic system-on-a- chip testing. The proposed solution is based on a new test data decompression architecture which exploits the fea- tures of a core wrapper design algorithm targeting the elimination of useless test data. The compressed test data can be transferred from the automatic test

Paul Theo Gonciari; Bashir M. Al-hashimi; Nicola Nicolicit

2002-01-01

146

Common Core Curriculum for Vocational Education. Category G: Evaluation and Research. G-4: Research Design in Vocational Education.  

ERIC Educational Resources Information Center

|This module on research design in vocational education is one of a set of five on evaluation and research and is part of a larger series of thirty-four modules constituting a core curriculum for use in the professional preparation of vocational educators in the areas of agricultural, business, home economics, and industrial education. Following…

Moshier, Kenneth

147

Four different core materials measured for fracture strength in combination with five different designs of endodontic posts  

Microsoft Academic Search

The purpose of this in vitro study was to determine the fractural load of four core materials supported by five post designs. This study was divided into 20 groups with 10 samples per group. Specimens were placed in a special jig at a 45-degree angle, and the fracture load values, in pounds, were obtained with the use of a universal

Brett I Cohen; Mark K Pagnillo; Spyridon Condos; Allan S Deutsch

1996-01-01

148

Tuning light absorption in core/shell silicon nanowire photovoltaic devices through morphological design.  

PubMed

Subwavelength diameter semiconductor nanowires can support optical resonances with anomalously large absorption cross sections, and thus tailoring these resonances to specific frequencies could enable a number of nanophotonic applications. Here, we report the design and synthesis of core/shell p-type/intrinsic/n-type (p/i/n) Si nanowires (NWs) with different sizes and cross-sectional morphologies as well as measurement and simulation of photocurrent spectra from single-NW devices fabricated from these NW building blocks. Approximately hexagonal cross-section p/i/n coaxial NWs of various diameters (170-380 nm) were controllably synthesized by changing the Au catalyst diameter, which determines core diameter, as well as shell deposition time, which determines shell thickness. Measured polarization-resolved photocurrent spectra exhibit well-defined diameter-dependent peaks. The corresponding external quantum efficiency (EQE) spectra calculated from these data show good quantitative agreement with finite-difference time-domain (FDTD) simulations and allow assignment of the observed peaks to Fabry-Perot, whispering-gallery, and complex high-order resonant absorption modes. This comparison revealed a systematic red-shift of equivalent modes as a function of increasing NW diameter and a progressive increase in the number of resonances. In addition, tuning shell synthetic conditions to enable enhanced growth on select facets yielded NWs with approximately rectangular cross sections; analysis of transmission electron microscopy and scanning electron microscopy images demonstrate that growth of the n-type shell at 860 °C in the presence of phosphine leads to enhanced relative Si growth rates on the four {113} facets. Notably, polarization-resolved photocurrent spectra demonstrate that at longer wavelengths the rectangular cross-section NWs have narrow and significantly larger amplitude peaks with respect to similar size hexagonal NWs. A rectangular NW with a diameter of 260 nm yields a dominant mode centered at 570 nm with near-unity EQE in the transverse-electric polarized spectrum. Quantitative comparisons with FDTD simulations demonstrate that these new peaks arise from cavity modes with high symmetry that conform to the cross-sectional morphology of the rectangular NW, resulting in low optical loss of the mode. The ability to modulate absorption with changes in nanoscale morphology by controlled synthesis represents a promising route for developing new photovoltaic and optoelectronic devices. PMID:22889329

Kim, Sun-Kyung; Day, Robert W; Cahoon, James F; Kempa, Thomas J; Song, Kyung-Deok; Park, Hong-Gyu; Lieber, Charles M

2012-08-21

149

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

Microsoft Academic Search

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

Mitsuru KAMBE

2002-01-01

150

Design study of (2 x 2) core architecture for matrix multiplications via programmable graph architecture  

Microsoft Academic Search

This paper presents a 2 times 2 core architecture for matrix multiplications via the programmable graph architecture approach proposed earlier. A larger matrix-matrix multiplication can be carried out through sub-matrix decomposition. The iterative operation is completely performed with simple arithmetic operations and memory accesses. The core architecture is structurally described using Verilog and its functionality has been verified. Performance of

Jun-Hee Mun; Muling Peng; Sangjin Hong; A. Doboli; K. W. Tang

2005-01-01

151

Implementation of a cycle-based simulator for the design of a processor core  

Microsoft Academic Search

This paper presents an approach to establish and simulate a DSP core by using a cycle-based simulator written in C language. The simulator is written with information of a target DSP core. Instructions are analyzed in order to determine which blocks are used. Then, appropriate control signals are applied to the blocks. The implemented simulator can give the cycle-based information

Moon Gyung Rim; Byung In Moon; Sang Jun An; Dong Ryul Ryu; Yong Surk Lee

1999-01-01

152

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

PubMed

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

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

2012-08-01

153

Suspended nanowires: fabrication, design and characterization of fibers with nanoscale cores.  

PubMed

We report a new approach for the fabrication of nanowires: the direct drawing of optical fibers with air suspended nanoscale cores. The fibers were made from lead silicate glass using the extrusion technique for preform and jacket tube fabrication. Fibers with core diameters in the range of 420-720 nm and practical outer diameters of 110-200 microm were produced, the smallest core sizes produced to date within optical fibers without tapering. We explored the impact of the core size on the effective mode area and propagation loss of these suspended nanowires relative to circular nanowires reported to date. As for circular nanowires, the propagation loss of these suspended nanowires is dominated by surface roughness induced scattering. PMID:19219168

Ebendorff-Heidepriem, Heike; Warren-Smith, Stephen C; Monro, Tanya M

2009-02-16

154

Inner core segment design for drug delivery control of thermo-responsive polymeric micelles  

Microsoft Academic Search

Modification of the thermo-responsive behavior of polymeric micelles for specific drug delivery functions was investigated using combinations of micellar inner cores and outer shell polymer chemistries. Polymeric micelles comprised of AB block copolymers of PIPAAm (poly(N-isopropylacrylamide)) with either PBMA (poly(butyl methacrylate)) or PSt (polystyrene) were employed. PIPAAm–PBMA and PIPAAm–PSt block copolymers formed a core-shell micellar structure after dialysis of the

Joo Eun Chung; Masayuki Yokoyama; Teruo Okano

2000-01-01

155

Core thermal response and hydrogen generation of the N Reactor hydrogen mitigation design basis accident  

SciTech Connect

Calculations were performed to determine core heatup, core damage, and subsequent hydrogen production of a hypothetical loss-of-cooling accident at the Department of Energy's N Reactor. The thermal transient response of the reactor core was solved using the TRUMP-BD computer program. Estimates of whole-core thermal damage and hydrogen production were made by weighting the results of multiple half-length pressure tube simulations at various power levels. The Baker-Just and Wilson parabolic rate equations for the metal-water chemical reactions modeled the key phenomena of chemical energy and hydrogen evolution. Unlimited steam was assumed available for continuous oxidation of exposed Zircaloy-2 surfaces and for uranium metal with fuel cladding beyond the failure temperature (1038 C). Intact fuel geometry was modeled. Maximum fuel temperatures (1181 C) in the cooled central regions of the core were predicted to occur one-half hour into the accident scenario. Maximum fuel temperatures of 1447 C occurred in the core GSCS-regions at the end of the 10-h transient. After 10-h 26% of the fuel inventory was predicted to have failed. Peak hydrogen evolution equaled 42 g/s, while 10-h integrated hydrogen evolution equaled 167 kg. 12 refs., 12 figs., 2 tabs.

White, M.D.; Lombardo, N.J.; Heard, F.J.; Ogden, D.M.; Quapp, W.J.

1988-04-01

156

Reactor core physics design and operating data for Cycles 1 and 2 of the Zion Unit 2 PWR power plant. Final report  

Microsoft Academic Search

A set of design and operating data relevant to Cycles 1 and 2 of the Zion Station Unit 2 pressurized water reactor (PWR) is presented. In general, these data constitute a substantial enhancement of fundamental information potentially usable in the process of validating PWR core analysis methodology. The design data is limited to the nuclear aspects of the core; thermal,

A. J. Jr. Impink; B. A. Guthrie

1979-01-01

157

Core-shell designed scaffolds of alginate/alpha-tricalcium phosphate for the loading and delivery of biological proteins.  

PubMed

Development of scaffolds to load and deliver therapeutic molecules like growth factors greatly enhances tissue regenerative capacity. Here, we report the core-shell design of fibrous scaffolds made of alginate and ?-tricalcium phosphate (Alg/?-TCP) for in situ protein loading and controllable delivery. Direct deposition of Alg/?-TCP solution through designed coconcentric nozzle in CaCl(2) bath allowed the generation of fibrous scaffolds. Through the process, in situ protein loading was possible and the core and shell composition was controlled. Feasibility of the designed scaffolds in loading and release of biological model protein cytochrome C (cyt C) was investigated. Scaffolding formed in CaCl(2) led to a considerable loss of cyt C in a crosslinking time-dependent manner, and the change in hardening conditions (Alg concentration, CaCl(2) concentration, and Alg/?-TCP ratio) was not as effective in reducing the protein loss. Subsequent release of cyt C from Alg scaffolds displayed a marked initial burst depending on crosslinking conditions, and shortening crosslinking time and decreasing CaCl(2) concentration lowered the initial burst. The ?-TCP addition (up to 75%) resulted in more continual and sustainable release patterns. Composition change (?-TCP content) in core or shell significantly altered the release profiles, suggesting the possible designing core-shell configuration for target release patterns, such as dual-protein delivery. Additionally, the ?-TCP incorporation significantly increased the mechanical stiffness to values much closer to those of hard tissues. Results indicate that coaxial deposited ?-TCP/Alg fibrous scaffolds may be useful for designing proper growth factor delivery systems in hard tissue engineering. PMID:23015482

Perez, Roman A; Kim, Hae-Won

2012-09-26

158

A Methodology for Selecting High Thermal-Hydraulic Performance Fuel Configurations for Tightly Packed Epithermal Core Designs  

SciTech Connect

Cylindrical fuel pins with wires are the design of choice for tightly packed fuel arrays. However, it is important to investigate novel fuel configurations in order to increase the thermal margins. Hence, new fuel designs have been studied for the epithermal option of the light water-cooled IRIS core. These designs are also of potential use in other tightly packed, epithermal advanced core designs.First, design equations have been used to determine number, height, and size of the principal features (clad, gap, fuel cross-sectional area) of the novel fuel configurations under investigation. Then, performance indices have been introduced to relate fuel geometrical characteristics to selected thermal-hydraulic parameters, such as pressure drop, critical heat flux (CHF), fuel centerline temperature, and clad surface temperature and stress distribution. Finally, variously shaped fuel configurations, including cylindrical, triangular, square, and hexagonal, have been ranked according to the performance indicators.The hexagonal fuel pins, both twisted and straight, proved to be good solutions for the epithermal tight core of the light water-cooled IRIS reactor, with performances comparable to those of the cylindrical fuel with wires. In particular, for water-to-fuel ratios {approx}0.33, the twisted hexagonal shape is the preferable design with a reduction of the total pressure drop by 16% and an increase of the CHF margin by 200%, compared to the traditional cylindrical pins with grids. Furthermore, the straight hexagonal shape allows flatter subchannel velocity profiles, wall shear stress, and wall temperature distributions. However, geometric constraints unfortunately do not allow application of the twisted hexagonal shape for smaller water-to-fuel ratios, which is a design regime of more favorable epithermal neutronics performance. In this regime, the cylindrical pins with wires are the solution of choice.

Romano, Antonino; Todreas, Neil E. [Massachusetts Institute of Technology (United States)

2002-07-15

159

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

SciTech Connect

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.

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

160

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

PubMed Central

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.

Buesser, B.; Pratsinis, S.E.

2013-01-01

161

Effect of toothless stator design and core and stator conductors eddy current losses in permanent magnet generators  

Microsoft Academic Search

Some advantages of toothless stator design in high-speed permanent magnet generators are presented. A computer-aided method was implemented to study the effect of stator teeth on the eddy current loss in the stator conductors as well as the core loss in the laminations of high-speed permanent magnet generators. The computer-aided method was applied to a 75 kVA, 208 V, 400

A. A. Arkadan; R. Vyas; J. G. Vaidya; M. J. Shah

1992-01-01

162

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

SciTech Connect

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.

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

1980-01-01

163

Design and synthesis of novel magnetic core-shell polymeric particles.  

PubMed

A novel synthetic strategy was developed for the preparation of magnetic core-shell (MCS) particles consisting of hydrophobic poly(methyl methacrylate) cores with hydrophilic chitosan shells and gamma-Fe2O3 nanoparticles inside the cores via copolymerization of methyl methacrylate from chitosan in the presence of vinyl-coated gamma-Fe2O3 nanoparticles. The magnetic core-shell particles were characterized with transmission electron microscopy, field-emission scanning electron microscopy, particle size and zeta-potential measurements, vibrating sample magnetometry, and atomic force microscopy, respectively. The MCS particles were less than 200 nm in diameter with a narrow size distribution (polydispersity = 1.09) and had a good colloidal stability (critical coagulation concentration = 1.2 M NaCl at pH 6.0). Magnetization study of the particles indicated that they exhibited superparamagnetism at room temperature and had a saturation magnetization of 2.7 A m2/kg. The MCS particles were able to form a continuous film on a glass substrate, where magnetic nanoparticles could evenly disperse throughout the film. Thus, these new materials should be extremely useful in various applications. PMID:18225930

Ho, Kin Man; Li, Pei

2008-01-29

164

Design, implementation, and evaluation of the linear road bnchmark on the stream processing core  

Microsoft Academic Search

Stream processing applications have recently gained signifi- cant attention in the networking and database community. At the core of these applications is a stream processing en- gine that performs resource allocation and management to support continuous tracking of queries over collections of physically-distributed and rapidly-updating data streams. While numerous stream processing systems exist, there has been little work on understanding

Navendu Jain; Lisa Amini; Henrique Andrade; Richard King; Philippe Selo; Chitra Venkatramani

2006-01-01

165

Optimal core shape design for cogging torque reduction of brushless DC motor using genetic algorithm  

Microsoft Academic Search

The cogging torque in the small brushless DC (BLDC) motors used in the digital versatile disk (DVD) driving system or hard disk drive (HDD) system can cause some serious vibration problems. In this paper, some core shapes that reduce cogging torque are found by using the reluctance network method (RNM) for magnetic field analysis and genetic algorithms (GAs) for optimization.

Ki-Jin Han; Han-Sam Cho; Dong-Hyeok Cho; Hyun-Kyo Jung

2000-01-01

166

Conceptual design of the ITER core imaging x-ray spectrometer  

Microsoft Academic Search

Summary form only given. The core ion temperature and bulk ion velocity of ITER plasmas will likely be derived from the thermal Doppler broadening and Doppler shift of X-ray lines emitted by highly charged trace elements and recorded by an array of high-resolution spectrometers. Although several elements could be used to seed the plasma for this purpose, we show that

P. Beiersdorfer; J. Clementson; J. Dunn; K. Morris; M. Bitter; D. Johnson; K. W. Hill; M.-F. Gu; Y. Podpaly; R. Barnsley

2009-01-01

167

Three pass core design proposal for a high performance light water reactor  

Microsoft Academic Search

The paper describes a novel core concept for a nuclear reactor cooled with supercritical water, in which the coolant is heated up from 280°C at the reactor inlet to 500°C at the outlet in four steps: a first heat-up step is provided by heat transfer from fuel assemblies to the moderator water in gaps and moderator boxes, a second step

T. Schulenberg; J. Starflinger; J. Heinecke

2008-01-01

168

Design and Test of the Borosilicate Glass Burnable Poison Rod for Qinshan Nuclear Power Plant Core.  

National Technical Information Service (NTIS)

Material for the burnable poison of Qinshan Nuclear Power Plant core is GG-17 borosilicate glass. The chemical composition and physico-chemical properties of GG-17 is very close to Pyrex-7740 glass used by Westinghouse. It is expected from the results of ...

J. Huang H. Sun

1988-01-01

169

Stress analysis, code evaluation, and design modification of a plate resulting from seismic loads and hypothetical core disruptive accident loads  

SciTech Connect

This study addresses the structural analysis and evaluation of a design modification for a plate in the Fast Flux Test Facility heat temperature control system. The plate being considered is near a fuel transfer port system. The plate is flat and is supported by six long studs, five of which are along one side of the plate. Their location makes the plate act as a cantilever.The plate itself provides support to three vertical neutron shields on its free edges. During service, a uranium shield ring under the fuel transfer port nozzle oxidized and expanded. To prevent this expansion from causing damage to the surrounding components, this ring was removed and replaced with lead blocks. Approximately one-fourth of the lead blocks rest on a free edge of the plate. This new configuration of the plate required updated seismic and hypothetical core disruptive accident analyses. Seismic and hypothetical core disruptive accident analyses were performed and checked against the requirements of the American Society of Mechanical Engineers Code. The result showed that the design of the existing plate supports (the six studs) was not adequate for the added weight of the lead blocks. The design was modified to restrain the lead blocks. When the final design with modified boundary conditions was reevaluated, the stress results satisfied the Code requirements.

Rezvani, M.A.; Ziada, H.H.

1992-01-01

170

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

NASA Astrophysics Data System (ADS)

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.

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

2003-09-01

171

The Design of Core 2: A Library for Exact Numeric Computation in Geometry and Algebra  

Microsoft Academic Search

\\u000a There is a growing interest in numeric-algebraic techniques in the computer algebra community as such techniques can speed\\u000a up many applications. This paper is concerned with one such approach called Exact Numeric Computation (ENC). The ENC approach to algebraic number computation is based on iterative verified approximations, combined with constructive\\u000a zero bounds. This paper describes Core 2, the latest version

Jihun Yu; Chee Yap; Zilin Du; Sylvain Pion; Hervé Brönnimann

2010-01-01

172

Hierarchy-Aware and Area-Efficient Test Infrastructure Design for Core-Based System Chips  

Microsoft Academic Search

Multiple levels of design hierarchy are common in current-generation system-on-chip (SOC) integrated circuits. However, most prior work on test access mechanism (TAM) optimization and test scheduling is based on a flattened design hierarchy. We investigate hierarchy-aware test infrastructure design, wherein wrapper\\/TAM optimization and test scheduling are carried out for hierarchical SOCs for two practical design scenarios. In the first scenario,

A. Sehgal; S. K. Goel; E. J. Marinissen; Krishnendu Chakrabarty

2006-01-01

173

Hierarchy-aware and area-efficient test infrastructure design for core-based system chips  

Microsoft Academic Search

Multiple levels of design hierarchy are common in current- generation system-on-chip (SOC) integrated circuits. However, most prior work on test access mechanism (TAM) optimization and test scheduling is based on a flattened design hierarchy. We investigate hierarchy-aware test infrastructure design, wherein wrapper\\/TAM optimization and test scheduling are carried out for hierarchical SOCs for two practical design scenarios. In the first

Anuja Sehgal; Sandeep Kumar Goel; Erik Jan Marinissen; Krishnendu Chakrabarty

2006-01-01

174

Conceptual design analysis of an MHD power conversion system for droplet-vapor core reactors. Final report  

SciTech Connect

A nuclear driven magnetohydrodynamic (MHD) generator system is proposed for the space nuclear applications of few hundreds of megawatts. The MHD generator is coupled to a vapor-droplet core reactor that delivers partially ionized fissioning plasma at temperatures in range of 3,000 to 4,000 K. A detailed MHD model is developed to analyze the basic electrodynamics phenomena and to perform the design analysis of the nuclear driven MHD generator. An incompressible quasi one dimensional model is also developed to perform parametric analyses.

Anghaie, S.; Saraph, G.

1995-12-31

175

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.  

National Technical Information Service (NTIS)

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 l...

T. A. Parish

1995-01-01

176

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

SciTech Connect

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.

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

177

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

Microsoft Academic Search

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

Venkata Syam P. Rapaka; Emil Talpes; Diana Marculescu

2004-01-01

178

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

Microsoft Academic Search

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

M. T. Farmer

2009-01-01

179

Weapons-Grade Plutonium-Thorium PWR Assembly Design and Core Safety Analysis  

Microsoft Academic Search

A light water reactor (LWR) fuel assembly design consisting of a blend of weapons-grade plutonium and natural thorium oxides was examined. The design meets current thermal-hydraulic and safety criteria. Such an assembly would have enough reactivity to achieve three cycles of operation. The pin power distribution indicates a fairly level distribution across the assembly, avoiding hot spots near guide tubes,

David Dziadosz; Timothy N. Ake; Mehmet Saglam; Joe J. Sapyta

2004-01-01

180

Is the sheet-flow design a ‘frozen core’ (a Bauplan) of the gas exchangers?  

Microsoft Academic Search

The sheet-flow design is ubiquitous in the respiratory microvascular systems of the modern gas exchangers. The blood percolates through a maze of narrow microvascular channels spreading out into a thin film, a “sheet”. The design has been convergently conceived through remarkably different evolutionary strategies. Endothelial cells, e.g. connect parallel epithelial cells in the fish gills and reptilian lungs; epithelial cells

J. N Maina

2000-01-01

181

The evolutionarily conserved core design of the catalytic activation step of the yeast spliceosome.  

PubMed

Metazoan spliceosomes exhibit an elaborate protein composition required for canonical and alternative splicing. Thus, the minimal set of proteins essential for activation and catalysis remains elusive. We therefore purified in vitro assembled, precatalytic spliceosomal complex B, activated B(act), and step 1 complex C from the simple eukaryote Saccharomyces cerevisiae. Mass spectrometry revealed that yeast spliceosomes contain fewer proteins than metazoans and that each functional stage is very homogeneous. Dramatic compositional changes convert B to B(act), which is composed of approximately 40 evolutionarily conserved proteins that organize the catalytic core. Additional remodeling occurs concomitant with step 1, during which nine proteins are recruited to form complex C. The moderate number of proteins recruited to complex C will allow investigations of the chemical reactions in a fully defined system. Electron microscopy reveals high-quality images of yeast spliceosomes at defined functional stages, indicating that they are well-suited for three-dimensional structure analyses. PMID:19941820

Fabrizio, Patrizia; Dannenberg, Julia; Dube, Prakash; Kastner, Berthold; Stark, Holger; Urlaub, Henning; Lührmann, Reinhard

2009-11-25

182

A framework for core-level modeling and design of reconfigurable computing algorithms  

Microsoft Academic Search

Reconfigurable computing (RC) is rapidly becoming a vital technology for many applications, from high-performance computing to embedded systems. The inherent advantages of custom-logic hardware devices, such as the FPGA, combined with the versatility of software-driven hardware configuration often boost performance while reducing power consumption. However, compared to software design tools, the relatively immature state of RC design tools significantly limits

Gongyu Wang; Greg Stitt; Herman Lam; Alan D. George

2009-01-01

183

Customizing IP cores for system-on-chip designs using extensive external don't-cares  

Microsoft Academic Search

Abstract—Traditional digital circuit synthesis flows start from an HDL behavioral definition and assume that circuit functions are almost completely defined, making don’t-care conditions rare. However, recent design methodologies do not always satisfy these assumptions. For instance, third-party IP blocks used in a system- on-chip are often over-designed for the requirements at hand. By focusing only on the input combinations occurring

Kai-hui Chang; Valeria Bertacco; Igor L. Markov

2009-01-01

184

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

SciTech Connect

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.

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

2012-02-08

185

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

SciTech Connect

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.

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

186

Drive Turbine System for 20-Inch Turbofan Simulators. 2 Core Turbine Design.  

National Technical Information Service (NTIS)

Drive-turbines for a given set of 20-inch turbo-fan simulators are described. The simulators had both single-stage and two-stage fans that had design pressure ratios as low as 1.25 and as high as 3.0. The desired objective of the study was to be able to d...

W. J. Whitney

1972-01-01

187

Soft Magnetic Composite Core - A New Perspective For Small AC Motors Design  

Microsoft Academic Search

In the paper is presented a new design of a small permanent magnet AC motor, based on the application of the soft magnetic composite (SMC) material, patented under the trade name SomaloyTM500 by Hoganas AB, Sweden. The new possibilities and perspectives of the SMC are analysed. This experimental work is a step further of the previous authors' research, dealing with

L. Petkovska; G. Cvetkovski

188

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

Microsoft Academic Search

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

P Beiersdorfer; J Wen; J Dunn; K Morris

2011-01-01

189

Design models for Robust Multi-Layer Next Generation Internet Core Networks Carrying Elastic Traffic  

Microsoft Academic Search

This paper presents three mathematical formula- tions for designing robust two-layer networks carrying elastic traffic. The formulations differ by the way flow reconfiguration is performed in the case of link failures. An iterative algorithm to solve the problems is given and an extensive numerical study is provided comparing the effectiveness of the three reconfiguration approaches. The formulations can be applied

Eligijus Kubilinskas; Michal Pióro; Pål Nilsson

2005-01-01

190

Core loss and torque ripple in IPM machines: dedicated modeling and design trade off  

Microsoft Academic Search

The proper combination of stator and rotor slot numbers is pursued in the design of Interior Permanent Magnet (IPM) motors with wide speed range. At high speed, in the flux-weakening region, the arising of the stator and rotor iron losses due to MMF spatial harmonics limits the IPM motor performance. Torque ripple is another problem for this kind of machines,

G. Pellegrino; P. Guglielmi; A. Vagati; F. Villata

2009-01-01

191

Melt Spreading Code Assessment, Modifications, and Application to the EPR Core Catcher Design.  

National Technical Information Service (NTIS)

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 (NR...

M. T. Farmer

2009-01-01

192

Design and development of a 3Phase saturated core High Temperature Superconducting Fault Current Limiter  

Microsoft Academic Search

The occurrence of fault currents and system sensitivity to fault currents are both increasing in modern power systems. Along with extensive damage to network hardware, considerable consumer losses (due to network unavailability) can result from fault current events. One device that is designed to reduce the impact of fault currents and increase network availability is the fault current limiter (FCL).

Jeff Moscrop; Frank Darmann

2009-01-01

193

Core Losses and Torque Ripple in IPM Machines: Dedicated Modeling and Design Tradeoff  

Microsoft Academic Search

The proper combination of stator and rotor slot numbers is pursued in the design of interior permanent-magnet (IPM) motors with wide constant-power speed range. At high speed, in the flux-weakening region, the arising of stator and rotor iron losses due to magnetomotive-force (MMF) spatial harmonics limits the IPM motor performance. Torque ripple is another problem for this kind of machines,

Gianmario Pellegrino; Paolo Guglielmi; Alfredo Vagati; Franco Villata

2010-01-01

194

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

SciTech Connect

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.

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

2011-05-23

195

[Design & fabrication of porous core implant with preset channel network for osteonecrosis of the femoral head].  

PubMed

Referring to the anatomical characterization of natural spongy bone and channel network in cortical bone, we designed a new pattern of biomimetic impalnt with preset channel for blood vessel inserting to treat early femoral head necrosis. The surgical ptrocedure was simulated by CAD model. Ceramic stereolithography was applied to fabricate the green part. Other process, such as dehydration, rinsing, drying and sintering, were taken successively. The final ceramic part kept identical with the engineered part either in the shape or in the internal structure. No deformation or crack happened. Pore size, interconnected pore size, porosity and interconnected porosity of ceramic part could satisfy cellular grouth. Spectrum analysis showed that no phase transition or chemical reaction happened during fabrication process. The biocompatibility of the final part kept the same with original during beta-TCP powder. The compressive strength was 23.54 MPa, close to natural spongy bone. It is an ideal implant to treat early femoral head necroseis because it makes preimplantation of cells and biological factors, blood velssel inserting, early establishment of blood supply possible. At the same time, it could provide enough mechanical support to prevent collapse of femoral head. It could provide a wide clinical foreground. PMID:22097264

Bian, Weiguo; Li, Dichen; Lian, Qin; Zhang, Weijie; Zhu, Linzhong; Wang, Kunzheng

2011-10-01

196

High Level Analysis, Design and Validation of Distributed Mobile Systems with CoreASM  

NASA Astrophysics Data System (ADS)

System design is a creative activity calling for abstract models that facilitate reasoning about the key system attributes (desired requirements and resulting properties) so as to ensure these attributes are properly established prior to actually building a system. We explore here the practical side of using the abstract state machine (ASM) formalism in combination with the CoreASM open source tool environment for high-level design and experimental validation of complex distributed systems. Emphasizing the early phases of the design process, a guiding principle is to support freedom of experimentation by minimizing the need for encoding. CoreASM has been developed and tested building on a broad scope of applications, spanning computational criminology, maritime surveillance and situation analysis. We critically reexamine here the CoreASM project in light of three different application scenarios.

Farahbod, R.; Glässer, U.; Jackson, P. J.; Vajihollahi, M.

197

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

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

198

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

PubMed

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. PMID:24089827

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

2013-09-01

199

SOC and Multi-Core Debug: Are Design for Debug (DFD) features that are put in reuse cores sufficient for Silicon Debug?  

Microsoft Academic Search

Traditionally, developers of multi-core chips have relied upon system-level techniques such as boundary scan and external instrumentation to access internal signals during silicon debug. The system-on-a-chip (SoC) nature of the cell processor makes it more difficult to rely on these techniques, as the system bus is internal to the chip, and only a limited number of pins are accessible. The

M. Genden

2006-01-01

200

Inherently safe core design  

Microsoft Academic Search

This report summarizes the work performed on the hydraulically supported absorber balls shutdown assembly since the previous Status Review Meeting held in April 1978. The work included: water loop tests on a full-scale mockup of the assembly at the ETEC Hydraulic Test Facility; absorber balls location determination tests; hydraulic analysis; reactor transient analyses; and materials properties tests. The water loop

R. K. Paschall; D. K. Chung; A. S. Jackola; L. S. Eytel; R. R. Specht

1978-01-01

201

Design and development of a run-time monitor for multi-core architectures in cloud computing.  

PubMed

Cloud computing is a new information technology trend that moves computing and data away from desktops and portable PCs into large data centers. The basic principle of cloud computing is to deliver applications as services over the Internet as well as infrastructure. A cloud is a type of parallel and distributed system consisting of a collection of inter-connected and virtualized computers that are dynamically provisioned and presented as one or more unified computing resources. The large-scale distributed applications on a cloud require adaptive service-based software, which has the capability of monitoring system status changes, analyzing the monitored information, and adapting its service configuration while considering tradeoffs among multiple QoS features simultaneously. In this paper, we design and develop a Run-Time Monitor (RTM) which is a system software to monitor the application behavior at run-time, analyze the collected information, and optimize cloud computing resources for multi-core architectures. RTM monitors application software through library instrumentation as well as underlying hardware through a performance counter optimizing its computing configuration based on the analyzed data. PMID:22163811

Kang, Mikyung; Kang, Dong-In; Crago, Stephen P; Park, Gyung-Leen; Lee, Junghoon

2011-03-25

202

A Small High Performance Microprocessor Core Sirius for Embedded Low Power Designs, Demonstrated in a Medical Mass Application of an Electronic Pill(EPill®)  

Microsoft Academic Search

A new, small, and for low power optimized, processor core SIRIUS has been developed, simulated, synthesized to a netlist and verified. From this netlist, containing only primitives like gates and flip-flop s, a mapping to an ASIC technology or a FPGA technology can easily be done with existing synthesizer tools, allowing very complex SOC designs with several blocks. Emulation via

Dirk Jansen; Nidal Fawaz; Daniel Bau; Marc Durrenberger

2007-01-01

203

CONTINUOUSLY PRODUCED HONEYCOMB CORES  

Microsoft Academic Search

Today mechanical requirements and weight targets demand a lightweight sandwich design in many non-aerospace application areas. The large production cost of honeycomb core materials often prevents their use in low cost sandwich constructions. Other sandwich core materials however provide lower mechanical properties. The currently employed concepts for the production of honeycomb cores are reviewed to evaluate their potential for a

Jochen Pflug; Bart Vangrimde; Ignaas Verpoest

204

Study of the PWR REA pulse width for realistic UO2 and MOX core designs using 3D kinetics methods  

Microsoft Academic Search

For the development of new acceptance criteria for the analysis of Rod-Ejection-Accidents (REA) in Pressurized Water Reactor UO2 cores, full-width-at-half-maximum power pulse widths in the range 25–40ms were employed in the analytical transient fuel behaviour studies. Due to the operation of MOX cores in Switzerland, a study using the CORETRAN 3D kinetics code was carried out at PSI to investigate

Hakim Ferroukhi; Martin A. Zimmermann

2009-01-01

205

Use of data obtained from core tests in the design and operation of spent brine injection wells in geopressured or geothermal systems  

SciTech Connect

The effects of formation characteristics on injection well performance are reviewed. Use of data acquired from cores taken from injection horizons to predict injectivity is described. And methods for utilizing data from bench scale testing of brine and core samples to optimize injection well design are presented. Currently available methods and equipment provide data which enable the optimum design of injection wells through analysis of cores taken from injection zones. These methods also provide a means of identifying and correcting well injection problems. Methods described in this report are: bulk density measurement; porosity measurement; pore size distribution analysis; permeability measurement; formation grain size distribution analysis; core description (lithology) and composition; amount, type and distribution of clays and shales; connate water analysis; consolidatability of friable reservoir rocks; grain and pore characterization by scanning electron microscopy; grain and pore characterization by thin section analysis; permeability damage and enhancement tests; distribution of water-borne particles in porous media; and reservoir matrix acidizing effectiveness. The precise methods of obtaining this information are described, and their use in the engineering of injection wells is illustrated by examples, where applicable. (MHR)

Jorda, R.M.

1980-03-01

206

Are Design for Debug (DFD) Features that are Put in Reuse Cores Sufficient for Silicon Debug? - position statement  

Microsoft Academic Search

What types of debug capability can currently be found in cores? The first thing that comes to mind is scan. Though scan was originally implemented in order to get high fault coverage, it can also be used for debug. For instance, if there is an asynchronous switch from functional mode to scan mode, a functional test can be run, stopped

Teresa L. McLaurin

2006-01-01

207

Design and material issues for high performance SiC f\\/SiC-based fusion power cores  

Microsoft Academic Search

The SiCf\\/SiC composite is a promising structural material candidate for fusion power cores and has been considered internationally in several power plant studies. It offers safety advantages arising from its low induced radioactivity and afterheat, and the possibility of high performance through high temperature operation. However, its behavior and performance at high temperatures and under irradiation are still not well

A. R. Raffray; R. Jones; G. Aiello; M. Billone; L. Giancarli; H. Golfier; A. Hasegawa; Y. Katoh; A. Kohyama; S. Nishio; B. Riccardi; M. S. Tillack

2001-01-01

208

US Higher Education Environmental Program Managers' Perspectives on Curriculum Design and Core Competencies: Implications for Sustainability as a Guiding Framework  

ERIC Educational Resources Information Center

|Purpose: This study is the first of a five-phase research project sponsored by the Council of Environmental Deans and Directors (CEDD), an organization of environmental program managers operating under the umbrella of the National Council for Science and the Environment. The purpose of the project is to determine if a consensus on core

Vincent, Shirley; Focht, Will

2009-01-01

209

US higher education environmental program managers' perspectives on curriculum design and core competencies : Implications for sustainability as a guiding framework  

Microsoft Academic Search

Purpose – This study is the first of a five-phase research project sponsored by the Council of Environmental Deans and Directors (CEDD), an organization of environmental program managers operating under the umbrella of the National Council for Science and the Environment. The purpose of the project is to determine if a consensus on core competencies for environmental program graduates is

Shirley Vincent; Will Focht

2009-01-01

210

Comparison of MARC Content Designation Utilization in OCLC WorldCat Records with National, Core, and Minimal Level Record Standards  

Microsoft Academic Search

Commonly used fields and subfields in 56 million Online Computer Library Center (OCLC) WorldCat bibliographic records are identified based on the analysis of format-specific record sets and the calculation of utilization thresholds, with the purpose of comparing these elements with existing recommendations by Library of Congress (LC) agencies for national, core, and minimal level records. The background and purposes of

Amy P. Eklund; Shawne D. Miksa; William E. Moen; Gregory Snyder; Serhiy Polyakov

2009-01-01

211

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

Microsoft Academic Search

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

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

2010-01-01

212

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

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.

Parish, T.A.

1995-03-02

213

Design of nonlinear photonic crystal fibers with a double-cladded coaxial core for zero chromatic dispersion.  

PubMed

Photonic crystal fiber (PCF) with a double-cladded coaxial core (CC) is proposed and analyzed to obtain propagation characteristics such as chromatic dispersion, field distribution, and effective area. Only by doubling the number of air holes to 12 in the inner hexagonal cladding layer with one pitch (?) value can the chromatic dispersion shift close to zero be achieved at 1.55 ?m operation wavelength. The fundamental mode field for the double-cladded CCPCF is tightly confined to the central core region. Therefore, the effective area is normally very small, while it tends to be larger rather rapidly as the operating wavelength is longer than around 1.7 ?m. PMID:23033108

Kim, Jeong

2012-10-01

214

High-Inductance-Density, Air-Core, Power Inductors, and Transformers Designed for Operation at 100–500 MHz  

Microsoft Academic Search

This paper presents the microfabrication and measurement of high-inductance-density, moderate-Q, air-core inductors, and transformers intended for switch-mode power supplies operating in the 100-500 MHz frequency range. The inductors and transformers were fabricated on Pyrex substrates with four layers of electrodeposited copper with each layer up to 10 ¿m thick. Stacked winding layers allowed for mutual coupling between layers to increase

Christopher D. Meyer; Sarah S. Bedair; Brian C. Morgan; David P. Arnold

2010-01-01

215

Design of multifunctionalized ?-Fe 2 O 3 @SiO 2 core–shell nanoparticles for enzymes immobilization  

Microsoft Academic Search

This article deals with the first covalent grafting of an enzyme on twice functionalized ?-Fe2O3@SiO2 core–shell magnetic nanoparticles. First, amino-PEG functionalized nanoparticles were synthesized in order to comply with\\u000a non-toxic platforms that would be stable in high concentration and would exhibit chemical groups to allow further coupling\\u000a with biomolecules. This approach produces a colloidal suspension of covalently grafted enzymes that

Thomas Georgelin; Vincent Maurice; Bernard Malezieux; Jean-Michel Siaugue; Valerie Cabuil

2010-01-01

216

Genomic design of strong direct-gap optical transition in Si/Ge core/multishell nanowires  

NASA Astrophysics Data System (ADS)

Converting the electronically superior but optically impractical indirect-gap Si and Ge semiconductors into a strongly light-absorbing system has been a long-standing challenge, given that the phonon-assisted optical transition of the indirect gap has weak intensity, requiring thick absorbers. One of main strategies has been the use of two-dimensional (2D) layer-by-layer growth of Si/Ge superlattices (SLs). However, the maximum thickness of SLs that can be grown coherently on a substrate is limited by the lattice-mismatch-induced strain. This limitation can be greatly relaxed by changing from 2D SLs to one-dimensional quantum nanowire (NW), where much higher strain can be accommodated. With developed Vapor-Liquid-Solid based technique, experimental growth of Si/Ge core-multishell NWs has recently demonstrated a significant level of synthetic control. However, the number of possible core/multishell sequences and thicknesses might easily reach an astronomic value. We will present here a genomic search for targeted core/multishell NW geometries that give both a direct gap and a significantly enhanced dipole-allowed optical transition in the Si/Ge system, by using a combination of genetic algorithm with atomistic pseudopotential electronic-structure calculations.

Zhang, Lijun; D'Avezac, Mayeul; Luo, Jun-Wei; Zunger, Alex

2012-02-01

217

HYDRATE CORE DRILLING TESTS  

SciTech Connect

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.

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

2002-11-01

218

An efficient FPGA-based dynamic partial reconfiguration design flow and environment for image and signal processing IP cores  

Microsoft Academic Search

This paper describes a dynamic partial reconfiguration (DPR) design flow and environment for image and signal processing algorithms used in adaptive applications. Based on the evaluation of the existing DPR design flow, important features such as overall flexibility, application and standardised interfaces, host applications and DPR area\\/size placement have been taken into consideration in the proposed design flow and environment.

Benjamin Krill; Afandi Ahmad; Abbes Amira; Hassan Rabah

2010-01-01

219

Transitions, Risks, and Actions in Coronary Events - Center for Outcomes Research and Education (TRACE-CORE): Design and Rationale  

PubMed Central

Background Cardiovascular disease continues to cause significant morbidity, mortality, and impaired quality of life, with unrealized health gains from the underuse of available evidence. The Transitions, Risks, and Actions in Coronary Events Center for Outcomes Research and Education (TRACE-CORE) aims to advance the science of acute coronary syndromes (ACS) by examining the determinants and outcomes of the quality of the transition from the hospital to the community and by quantifying the impact of potentially-modifiable characteristics associated with decreased quality of life, rehospitalization, and mortality. Methods and Results TRACE-CORE is composed of a longitudinal multi-racial cohort of patients hospitalized with ACS, two research projects, and development of a nucleus of early stage investigators. We are currently enrolling 2,500 adults hospitalized for ACS at 6 hospitals in the northeastern and southeastern United States. We will follow these patients for 24 months after hospitalization through medical record abstraction and six patient interviews focusing on quality of life, cardiac events, rehospitalizations, mortality, and medical, behavioral, and psychosocial characteristics. The Transitions Project studies determinants of and disparities in outcomes of the quality of patients’ transition from the hospital to the community. Focusing on potentially modifiable factors, the Action Scores Project will develop and validate action scores to predict recurrent cardiac events, death, and quality of life, describe longitudinal variation in these scores, and develop a dashboard for patient and provider action based on these scores. Conclusions In TRACE-CORE, sound methodologic principles of observational studies converge with outcomes and effectiveness research approaches. We expect that our data, research infrastructure, and research projects will inform the development of novel secondary prevention approaches and underpin the careers of CVD outcomes researchers.

Waring, Molly E.; McManus, Richard H.; Saczynski, Jane S.; Anatchkova, Milena D.; McManus, David D.; Devereaux, Randolph S.; Goldberg, Robert J.; Allison, Jeroan J.; Kiefe, Catarina I.

2012-01-01

220

Core-shell designs of photoluminescent nanodiamonds with porous silica coatings for bioimaging and drug delivery II: application  

NASA Astrophysics Data System (ADS)

Recent advances within materials science and its interdisciplinary applications in biomedicine have emphasized the potential of using a single multifunctional composite material for concurrent drug delivery and biomedical imaging. Here we present a novel composite material consisting of a photoluminescent nanodiamond (ND) core with a porous silica (SiO2) shell. This novel multifunctional probe serves as an alternative nanomaterial to address the existing problems with delivery and subsequent tracing of the particles. Whereas the unique optical properties of ND allows for long-term live cell imaging and tracking of cellular processes, mesoporous silica nanoparticles (MSNs) have proven to be efficient drug carriers. The advantages of both ND and MSNs were hereby integrated in the new composite material, ND@MSN. The optical properties provided by the ND core rendered the nanocomposite suitable for microscopy imaging in fluorescence and reflectance mode, as well as super-resolution microscopy as a STED label; whereas the porous silica coating provided efficient intracellular delivery capacity, especially in surface-functionalized form. This study serves as a demonstration how this novel nanomaterial can be exploited for both bioimaging and drug delivery for future theranostic applications.Recent advances within materials science and its interdisciplinary applications in biomedicine have emphasized the potential of using a single multifunctional composite material for concurrent drug delivery and biomedical imaging. Here we present a novel composite material consisting of a photoluminescent nanodiamond (ND) core with a porous silica (SiO2) shell. This novel multifunctional probe serves as an alternative nanomaterial to address the existing problems with delivery and subsequent tracing of the particles. Whereas the unique optical properties of ND allows for long-term live cell imaging and tracking of cellular processes, mesoporous silica nanoparticles (MSNs) have proven to be efficient drug carriers. The advantages of both ND and MSNs were hereby integrated in the new composite material, ND@MSN. The optical properties provided by the ND core rendered the nanocomposite suitable for microscopy imaging in fluorescence and reflectance mode, as well as super-resolution microscopy as a STED label; whereas the porous silica coating provided efficient intracellular delivery capacity, especially in surface-functionalized form. This study serves as a demonstration how this novel nanomaterial can be exploited for both bioimaging and drug delivery for future theranostic applications. Electronic supplementary information (ESI) available: DLS and electrokinetic measurements, optical size measurements from PL-signal of individual particles by confocal and STED microscopy, TEM image showing the subcellular localization of pure ND. See DOI: 10.1039/c3nr33926b

Prabhakar, Neeraj; Näreoja, Tuomas; von Haartman, Eva; Karaman, Didem ?en; Jiang, Hua; Koho, Sami; Dolenko, Tatiana A.; Hänninen, Pekka E.; Vlasov, Denis I.; Ralchenko, Victor G.; Hosomi, Satoru; Vlasov, Igor I.; Sahlgren, Cecilia; Rosenholm, Jessica M.

2013-04-01

221

Recent developments in pressure coring  

SciTech Connect

The current rapid growth in the number of enhanced oil and gas recovery projects has created a strong demand for reservoir data such as true residual oil saturations. The companies providing pressure coring services have moved to fill this need. Two recent developments have emerged with the potential of significantly improving the present performance of pressure coring. Coring bits utilizing synthetic diamond cutters have demonstrated coring rates of one-foot per minute while improving core recovery. It is also apparent that cores of a near-unconsolidated nature are more easily recovered. In addition, a special low invasion fluid that is placed in the core retriever has demonstrated reduced core washing by the drilling mud and a decrease in the complexity of preparing cores for analysis. This paper describes the design, laboratory, and field testing efforts that led to these coring improvements. Also, experience in utilizing these developments while recovering over 100 cores is discussed.

McFall, A. L.

1980-01-01

222

First-principles design of efficient solar cells using two-dimensional arrays of core-shell and layered SiGe nanowires  

NASA Astrophysics Data System (ADS)

Research for third generation solar cell technology has been driven by the need to overcome the efficiency and cost problems encountered by current crystalline Si- and thin-film-based solar cells. Using first-principles methods, Ge/Si and Si/Ge core/shell and Si-Ge layered nanowires are shown to possess the required qualities for an efficient use in photovoltaic applications. We investigate the details of their band structure, effective mass, absorption property, and charge-carrier localization. The strong charge separation and improved absorption in the visible spectrum indicate a remarkable quantum efficiency that, combined with new designs, compares positively with bulk Si.

Peköz, R.; Malc?o?lu, O. B.; Raty, J.-Y.

2011-01-01

223

TMI2 core examination  

Microsoft Academic Search

The examination of the damaged core at the Three Mile Island Unit 2 (TMI-2) reactor is structured to address the following safety issues: fission product release, transport, and deposition; core coolability; containment integrity; and recriticality during severe accidents; as well as zircaloy cladding ballooning and oxidation during so-called design basis accidents. The numbers of TMI-2 components or samples to be

R. R. Hobbins; P. E. MacDonald; D. E. Owen

1983-01-01

224

Dublin Core: An Obituary  

Microsoft Academic Search

The Dublin Core Metadata Standard was conceived illegitimately, had a troubled life, and has finally met its demise. Developed as a tool for online resource discovery, the standard waned after the arrival of Google. Because its fields were designed with a lack of specificity, Dublin Core suffered from nonstandard data elements and poor interoperability. Also, the poor organization behind the

Jeffrey Beall

2004-01-01

225

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

SciTech Connect

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.

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

226

Rational design of core-shell molecularly imprinted polymer based on computational simulation and Doehlert experimental optimization: application to the separation of tanshinone IIA from Salvia miltiorrhiza Bunge.  

PubMed

Computational simulation and Doehlert experimental optimization were done for the rational design of a core-shell molecularly imprinted polymer (CS-MIP) for use in the highly selective separation of Tanshinone IIA (TSIIA) from the crude extracts of Salvia miltiorrhiza Bunge (SMB). The functional monomer layer of the polymer shells directed the selective occurrence of imprinting polymerization at the surface of silica through the copolymerization of vinyl end groups with functional monomers and also drove TSIIA templates into the formed polymer shells through the charge-transfer complex interactions between TSIIA and the functional monomer layer. As a result, the maximum rebinding capacity was achieved with the use of optimal grafting ratio by the Doehlert design. The CS-MIP exhibited high recognition selectivity and binding affinity to TSIIA. When the imprinted particles were used as dispersive solid phase extraction sorbents, the recovery yield of TSIIA reached 93% by a one-step extraction from the crude extracts of SMB, and the purity of TSIIA was larger than 98% by HPLC analysis. These results show the possibility of a highly selective separation and enrichment of TSIIA from the SMB using the TSIIA-imprinted core-shell molecularly imprinted polymers. PMID:22576658

Jia, Xianjun; Li, Hong; Luo, Jing; Lu, Qing; Peng, Yan; Shi, Liying; Liu, Liping; Du, Shuhu; Zhang, Guijun; Chen, Lina

2012-05-11

227

Reactor Physics Methods and Preconceptual Core Design Analyses for Conversion of the Advanced Test Reactor to Low-Enriched Uranium Fuel Annual Report for Fiscal Year 2012  

SciTech Connect

Under the current long-term DOE policy and planning scenario, both the ATR and the ATRC will be reconfigured at an appropriate time within the next several years to operate with low-enriched uranium (LEU) fuel. This will be accomplished under the auspices of the Reduced Enrichment Research and Test Reactor (RERTR) Program, administered by the DOE National Nuclear Security Administration (NNSA). At a minimum, the internal design and composition of the fuel element plates and support structure will change, to accommodate the need for low enrichment in a manner that maintains total core excess reactivity at a suitable level for anticipated operational needs throughout each cycle while respecting all control and shutdown margin requirements and power distribution limits. The complete engineering design and optimization of LEU cores for the ATR and the ATRC will require significant multi-year efforts in the areas of fuel design, development and testing, as well as a complete re-analysis of the relevant reactor physics parameters for a core composed of LEU fuel, with possible control system modifications. Ultimately, revalidation of the computational physics parameters per applicable national and international standards against data from experimental measurements for prototypes of the new ATR and ATRC core designs will also be required for Safety Analysis Report (SAR) changes to support routine operations with LEU. This report is focused on reactor physics analyses conducted during Fiscal Year (FY) 2012 to support the initial development of several potential preconceptual fuel element designs that are suitable candidates for further study and refinement during FY-2013 and beyond. In a separate, but related, effort in the general area of computational support for ATR operations, the Idaho National Laboratory (INL) is conducting a focused multiyear effort to introduce modern high-fidelity computational reactor physics software and associated validation protocols to replace several obsolete components of the current analytical tool set used for ATR neutronics support. This aggressive computational and experimental campaign will have a broad strategic impact on the operation of the ATR, both in terms of improved computational efficiency and accuracy for support of ongoing DOE programs as well as in terms of national and international recognition of the ATR National Scientific User Facility (NSUF). It will also greatly facilitate the LEU conversion effort, since the upgraded computational capabilities are now at a stage where they can be, and in fact have been, used for the required physics analysis from the beginning. In this context, extensive scoping neutronics analyses were completed for six preconceptual candidate LEU fuel element designs for the ATR (and for its companion critical facility, ATRC). Of these, four exhibited neutronics performance in what is believed to be an acceptable range. However, there are currently some concerns with regard to fabricability and mechanical performance that have emerged for one of the four latter concepts. Thus three concepts have been selected for more comprehensive conceptual design analysis during the upcoming fiscal year.

David W. Nigg; Sean R. Morrell

2012-09-01

228

Power Loss Testing System for Complex Electromagnetic Core Designs Used in New Direct Drive DC Brushless Motors  

Microsoft Academic Search

In direct drive DC brushless motor applications, the main incentive is to improve the form factor of the active magnetic design to increase the torque and power densities of the motor. Significant performance improvements in motor characteristics are seldom achieved with the use of conventional topologies based on laminated electrical steels. This is because there are classical limitations as to

Z. Soghomonian

229

Optical design and error analyses of lens for observing the fiber core based on the software ZEMAX  

Microsoft Academic Search

This paper introduces a magnifying lens group base on actual conditions. It is can be used in the detecting system to gate the magnified image of the energy distribution of the transmission light through the fiber. The magnification of the lens group is about eight. Image is received by a CCD. The lens is designed by using the software ZEMAX.

Jinglu Sun; Xiangning Li; Xuting Wu

2010-01-01

230

COLLABORATION BY DESIGN: INTEGRATING CORE PEDAGOGICAL CONTENT AND SPECIAL EDUCATION METHODS COURSES IN A PRESERVICE SECONDARY EDUCATION PROGRAM  

Microsoft Academic Search

In this article the authors describe a collaboratively designed secondary teacher education program focused on the preparation of preservice general education teachers to work effectively with children who have diverse learning needs in inclusive classrooms. The focus of the article is on the collaborative development and initial evaluation of the program by secondary teacher education faculty and special education faculty.

Timothy J. Frey; Debra K. Andres; Leah A. McKeeman

2012-01-01

231

Affective Educational Technology: First steps on th e introduction of the affective dimension in the core of online design  

Microsoft Academic Search

The cognitive or functional focus has traditional ly been the main key for instructional and technology designers, giving lower importance t o the emotional dimension. This point collides with the idea supported by multiple research studie s that cognitive and affective layers can not be separated and in order to enhance learning we have to promote appropriate affective states. In

Eva de Lera; Carles Fernàndez; Magí Almirall

232

The design of a hand-held K-factor meter using an air-core current transformer  

Microsoft Academic Search

This paper describes in detail the design of a portable microcontroller-based K-factor meter, or transformer harmonic derating factor meter. This innovative instrument is based on the recently developed time domain method for K-factor determination. K-factor is measured from the ratio of the rms value of the time derivative of a current to the rms value of this same current. The

Chih-Hsien Kung; Michael J. Devaney; Chung-Ming Huang

1997-01-01

233

The design of a hand-held K-factor meter using an air-core current transformer  

Microsoft Academic Search

This paper describes in detail the design of a portable microcontroller-based K-factor, or transformer harmonic derating factor, meter. This innovative instrument is based on the time-domain method for K-factor determination which relies on the ratio of the RMS value of the time derivative of a current to the RMS value of this same current. The meter employs the properties of

Chih-Hsien Kung; M. J. Devaney

1996-01-01

234

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

Microsoft Academic Search

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

John Lawrence Bencze

2010-01-01

235

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

SciTech Connect

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.

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

236

DUBLIN CORE  

EPA Science Inventory

The Dublin Core is a metadata element set intended to facilitate discovery of electronic resources. It was originally conceived for author-generated descriptions of Web resources, and the Dublin Core has attracted broad ranging international and interdisciplinary support. The cha...

237

24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES ...  

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

24. A CORE WORKER DISPLAYS THE CORE BOX AND CORES FOR A BRASS GATE VALVE BODY MADE ON A CORE BOX, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

238

[Optimization of a novel mucoadhesive drug deliver system with ion-exchange resin core loaded with berberine hydrochloride using central composite design methodology].  

PubMed

A novel mucoadhesive microcapsule with drug-resin complex core loaded with berberine hydrochloride (BH) was developed and optimized. Drug-ion exchange resin (IER) complex was prepared by static method which stirring IER in drug solution at certain conditions. The influences of different IERs, different temperature, pH values and concentrations of drug solution on the drug loading were investigated. IER complex was coated by emulsion-solvent evaporation method. The coating fluid formulation was optimized using central composite design-response surface methodology, where the ratio between Carbopol 934 and IER (X1), the ratio between Eudragit and IER (X2) and the ratio between Eudragit RL and RS (X3) were taken as independent variables. Time of cumulative release 85% (Y1) and percentage of gastric retention (Y2) were taken as response variables. Drug loading achieved a high level and more drug available in the condition of IER (IRP 88), 37 degrees C, pH 5 and 1.0 mg x mL(-1) drug solution. When X1 = 0.75, X2 = 0.9, X3 = 0.6, the time of cumulative release reached 85% at 300 min, the highest percentage of gastric retention in the range of this experiment were procured. PMID:19048791

Chen, Fei; Zhang, Yue; Liu, Qiang; Pang, Ming-zhi; Yang, Xing-gang; Pan, Wei-san

2008-09-01

239

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

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

Craig A. Steeves; Norman A. Fleck

2004-01-01

240

Core-tube data logger  

SciTech Connect

Wireline core drilling, increasingly used for geothermal exploration, employs a core-tube to capture a rock core sample during drilling. Three types of core-tube data loggers (CTDL) have been built and tested to date by Sandia national Laboratories. They are: (1) temperature-only logger, (2) temperature/inclinometer logger and (3) heat-shielded temperature/inclinometer logger. All were tested during core drilling operations using standard wireline diamond core drilling equipment. While these tools are designed for core-tube deployment, the tool lends itself to be adapted to other drilling modes and equipment. Topics covered in this paper include: (1) description on how the CTDLs are implemented, (2) the components of the system, (3) the type of data one can expect from this type of tool, (4) lessons learned, (5) comparison to its counterpart and (6) future work.

Henfling, J.A.; Normann, R.A.; Knudsen, S.; Drumheller, D.

1997-01-01

241

PIUS Core Performance Analysis.  

National Technical Information Service (NTIS)

A detailed evaluation of the fuel burnup dependent power distribution and the scram reactivity for the PIUS reactor design has been performed. The analyses were carried out using the CPM lattice physics and NODE-P2 core neutronics/thermal-hydraulics codes...

J. F. Carew A. Aronson D. M. Cokinos A. Prince E. C. Selcow

1996-01-01

242

MCNP LWR Core Generator  

SciTech Connect

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.

Fischer, Noah A. [Los Alamos National Laboratory

2012-08-14

243

PIUS core performance analysis  

SciTech Connect

A detailed evaluation of the fuel-burnup dependent power distribution and the scram reactivity for the PIUS reactor design has been performed. The analyses were carried out using the CPM lattice physics and NODE-P2 core neutronics/thermal-hydraulics codes, and are based on the information provided in the PIUS Preliminary Safety Information Document. Cycle depletion calculations were performed for a set of nine representative initial core loadings and the three-dimensional core power distributions were determined. These calculations indicate that the PIUS radial F{sub {Delta}h} and total F{sub Q} power peaking is stronger than that indicated by the PIUS reference-design values. The scram reactivity resulting from the injection of highly borated pool water was calculated for a series of time-dependent linear ramp and square-wave pool flows. The three-dimensional distribution of the borated pool water throughout the core was modeled and the spatial reactivity effects of the distributed boron were determined. For pool flows that increase as a linear ramp, the spatial reactivity effects of the distributed boron were very small. In this case, a constant core-average boron reactivity coefficient can be used to model the PIUS scram reactivity.

Carew, J.F.; Aronson, A.; Cokinos, D.M.; Prince, A.; Selcow, E.C.

1996-03-01

244

Deep Rotary Core Drilling in Ice.  

National Technical Information Service (NTIS)

Rotary drilling equipment was modified and used to obtain cores from glaciers in Northwest Greenland, Byrd Station and Little America V, Antarctica. Using cold compressed air, specially designed bits and other modifications, cores were obtained to 1345 fe...

G. R. Lange

1973-01-01

245

Cellular Truss Core Sandwich Structures  

Microsoft Academic Search

Sandwich structures with open cell truss cores are a relatively new class of multifunctional material systems that can be made using affordable deformation, assembly and joining processes. A variety of cellular core architectures have recently been made from wrought metal alloys using inexpensive textile and perforated sheet methods. Here, the design, fabrication and properties for these types of structures is

David J. Sypeck

2005-01-01

246

Droplet Core Nuclear Rocket (DCNR).  

National Technical Information Service (NTIS)

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...

S. Anghaie

1991-01-01

247

TMI-2 core examination  

SciTech Connect

The examination of the damaged core at the Three Mile Island Unit 2 (TMI-2) reactor is structured to address the following safety issues: fission product release, transport, and deposition; core coolability; containment integrity; and recriticality during severe accidents; as well as zircaloy cladding ballooning and oxidation during so-called design basis accidents. The numbers of TMI-2 components or samples to be examined, the priority of each examination, the safety issue addressed by each examination, the principal examination techniques to be employed, and the data to be obtained and the principal uses of the data are discussed in this paper.

Hobbins, R.R.; MacDonald, P.E.; Owen, D.E.

1983-01-01

248

Core breaker  

SciTech Connect

This patent describes a continuous mining machine having at least a pair of horizontally spaced and aligned rotatable cutter drums, an improved core breaker operatively associated with the cutter drums and comprising: an arcuate fixed support disposed between the drums; an elongated bit holder fixed to and extending outwardly from the support; the holder structure having a series of longitudinally spaced, core breaker bit accommodating apertures extending therethrough; each aperture being defined by a smaller diameter outer bore, a larger diameter inner bore and a shoulder extending generally normal to the aperture axis separating the bores; and a bit element and expansion ring assembly disposed in operative association with the cutter drums, accommodated in each aperture.

Morgan, V.B.; Mc Kinney, J.F.

1987-06-02

249

High Temperature Reactor (HTR) Deep Burn Core and Fuel Analysis: Design Selection for the Prismatic Block Reactor With Results from FY2011 Activities  

Microsoft Academic Search

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

Michael A. Pope

2011-01-01

250

Suitability of lost cores in rheocasting process  

Microsoft Academic Search

When treated in pressure die casting processes the semi-solid aluminum alloys demand resilient cores which can bear the stress occurring during filling and the final pressure phase. The design of permanent cores is highly restricted in order to maintain removability. Lost cores provide the possibility of complex, undercut geometrical shapes which is mandatory for a variety of casting components. However,

H. MICHELS; M. BÜNCK; A. BÜHRIG-POLACZEK

2010-01-01

251

Design and synthesis of highly luminescent near-infrared-emitting water-soluble CdTe/CdSe/ZnS core/shell/shell quantum dots.  

PubMed

Applications of water-dispersible near-infrared (NIR)-emitting quantum dots (QDs) have been hampered by their instability and low photoluminescence (PL) efficiencies. In this paper, water-soluble highly luminescent NIR-emitting QDs were developed through constructing CdTe/CdSe/ZnS core/shell/shell nanostructure. The CdTe/CdSe type-II structure yields the QDs with NIR emission. By varying the size of CdTe cores and the thickness of the CdSe shell, the emission wavelength of the obtained nanostructure can span from 540 to 825 nm. In addition, the passivation of the ZnS shell with a substantially wide bandgap confines the excitons within the CdTe/CdSe interface and isolates them from the solution environment and consequently improves the stability of the nanostructure, especially in aqueous media. An effective shell-coating route was developed for the preparation of CdTe/CdSe core/shell nanostructures by selecting capping reagents with a strong coordinating capacity and adopting a low temperature for shell deposition. An additional ZnS shell was deposited around the outer layer of CdTe/CdSe QDs to form the core/shell/shell nanostructure through the decomposition of single molecular precursor zinc diethyldithiocarbamate in the crude CdTe/CdSe reaction solution. The water solubilization of the initially oil-soluble CdTe/CdSe/ZnS QDs was achieved through ligand replacement by 3-mercaptopropionic acid. The as-prepared water-soluble CdTe/CdSe/ZnS QDs possess PL quantum yields as high as 84% in aqueous media, which is one of the best results for the luminescent semiconductor nanocrystals. PMID:19772326

Zhang, Wenjin; Chen, Guanjiao; Wang, Jian; Ye, Bang-Ce; Zhong, Xinhua

2009-10-19

252

First-principles design of efficient solar cells using two-dimensional arrays of core-shell and layered SiGe nanowires  

Microsoft Academic Search

Research for third generation solar cell technology has been driven by the need to overcome the efficiency and cost problems encountered by current crystalline Si- and thin-film-based solar cells. Using first-principles methods, Ge\\/Si and Si\\/Ge core\\/shell and Si-Ge layered nanowires are shown to possess the required qualities for an efficient use in photovoltaic applications. We investigate the details of their

R. Peköz; O. B. Malcioglu; J.-Y. Raty

2011-01-01

253

Modeling, Design, and Characterization of Multiturn Bondwire Inductors With Ferrite Epoxy Glob Cores for Power Supply System-on-Chip or System-in-Package Applications  

Microsoft Academic Search

The concept of coupled multiturn bondwire inductors with ferrite epoxy glob cores is investigated both experimentally and numerically to offer a cost-effective approach realizing power supply system-on-chip (PSoC) or system-in-package (PSiP). Improvement in total inductance and Q factor is demonstrated for the multiturn bondwire inductors due to the coupling effect. An empirical calculation method is developed to help determine the

Jian Lu; Hongwei Jia; Xuexin Wang; Karthik Padmanabhan; William Gerard Hurley; Zheng John Shen

2010-01-01

254

New directions in the coordination chemistry of 99mTc: a reflection on technetium core structures and a strategy for new chelate design  

Microsoft Academic Search

Bifunctional chelates offer a general approach for the linking of radioactive metal cations to macromolecules. In the specific case of 99mTc, a variety of technologies have been developed for assembling a metal–chelate–biomolecule complex. An evaluation of these methodologies requires an appreciation of the coordination characteristics and preferences of the technetium core structures and oxidation states, which serve as platforms for

Sangeeta Ray Banerjee; Kevin P. Maresca; Lynn Francesconi; John Valliant; John W. Babich; Jon Zubieta

2005-01-01

255

CopperCore Service Integration  

ERIC Educational Resources Information Center

|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…

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

2007-01-01

256

Designed fabrication of unique eccentric mesoporous silica nanocluster-based core-shell nanostructures for pH-responsive drug delivery.  

PubMed

A novel and facile strategy using poly(acrylic acid) (PAA) as a nanoreactor and template has been proposed and applied for the first time to fabricate a novel and unique class of multifunctional eccentric Fe3O4@PAA/SiO2 core-shell nanoclusters (NCs) consisting of a single Fe3O4 nanoparticle (NP), PAA, and eccentric SiO2 NCs that are composed of a large number of small fluorescent SiO2 NPs. Interestingly, the resulting eccentric PAA shell around Fe3O4 NPs as a high water-absorbent polymer is like a "reservoir" to absorb and retain water molecules inside its net structure to confine the growth of small SiO2 NPs inside the PAA networks, resulting in the formation of an eccentric SiO2 NC with aggregated pores. The thicknesses of uniform and well-dispersed SiO2 NCs can also be precisely controlled by varying the amount of tetraethyl orthosilicate (TEOS). Importantly, the synthetic method has been confirmed to be universal and extended to other functional NPs with different compositions and shapes as eccentric cores. Furthermore, the as-prepared multifunctional eccentric Fe3O4@PAA/SiO2 core-shell NCs combined fluorescence imaging, ultrahigh drug loading capacity (1.13 mg doxorubicin/mg eccentric NCs), and pH-responsive drug release into one were taken as an example to study the applications in simultaneous fluorescence imaging and pH responsive drug delivery into prostate cancer PC3M cells. PMID:23808730

Chen, Lulu; Li, Lu; Zhang, Lingyu; Xing, Shuangxi; Wang, Tingting; Wang, Y Andrew; Wang, Chungang; Su, Zhongmin

2013-07-17

257

Test and evaluation of aluminum drill pipe for deep-water coring: design and use of heavy-wall drilling joints for bending stress reduction. Technical report  

SciTech Connect

The report includes two papers dealing with means of extending the drill string depth capability and lowering stresses at the top of the drill string. The first paper reports on the operational use of a 2000 foot section of aluminum drill pipe in a mixed aluminum/steel drill string. The report also discusses metallurgical laboratory tests and assesses the potential of mixed strings for use in wireline coring operations to 30,000 feet. The second deals with the development and test of drilling joints used to reduce stresses at the upper end of the drill string.

Peterson, M.N.A.

1984-02-01

258

Design.  

ERIC Educational Resources Information Center

|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…

Online-Offline, 1998

1998-01-01

259

Design.  

ERIC Educational Resources Information Center

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…

Online-Offline, 1998

1998-01-01

260

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

PubMed

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

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

2012-10-23

261

Residential Utility Core Wall System - ResCore  

SciTech Connect

This paper describes activities associated with the RESidential utility CORE wall system (ResCore) developed by students and faculty in the Department of Industrial Design at Auburn University between 1996 and 1998. These activities analyize three operational prototype units installed in Habitat for Humanity Houses. The paper contains two Parts: 1) analysis of the three operational prototype units, 2) exploration of alternative design solutions. ResCore is a manufactured construction component designed to expedite home building by decreasing the need for skilled labor at the work site. The unit concentrates untility elements into a wall unit(s), which is shipped to the construction site and installed in minimum time. The ResCore unit is intended to be built off-site in a manufacturing environment where the impact of vagaries of weather and work-crew coordination and scheduling are minimized. The controlled environment of the factory enhances efficient production of building components through material and labor throughput controls, enabling the production of components at a substantially reduced per-unit cost. The ResCore unit when compared to traditional "stick-built" utility wall components is in may ways analogous to the factory built roof truss compared to on-site "stick-Built" roof framing.

Boyd, G.; Lundell, C.; Wendt, R.

1999-06-01

262

Evaluation of the core physics and safety characteristics of a quasi-homogeneous LMFBR concept  

Microsoft Academic Search

A core design concept utilizing two types of driver assemblies that differ in fuel pin diameter has been investigated as an alternative to the heterogeneous LMFBR core for achieving low HCDA energetics. Core designs based on the (quasi-homogeneous) concept were developed and their performance compared to that of standard homogeneous and hetergeneous cores. It is shown that quasi-homogenous cores can

H. Khalil; B. S. Yarlagadda

1984-01-01

263

Banner Core Simulation Interface.  

National Technical Information Service (NTIS)

The Banner Core Simulation Interface tool has been developed by Rome Laboratory to support the Banner Core program in evaluating Bistatic Radar Systems. This document provides a summary of the objectives of the Banner Core program, the software capabiliti...

L. Mabius

2000-01-01

264

Design of a core-shell type immuno-magnetic separation system and multiplex PCR for rapid detection of pathogens from food samples.  

PubMed

We report an immuno-magnetic separation system developed by the immobilization of pathogen-specific antibodies on the core-shell magnetic beads. The magnetic beads were grafted with glycidylmethacrylate (GMA) using surface-initiated atom transfer radical polymerization (SI-ATRP). For immuno-magnetic separation (IMS) of target bacterial cells from others, antibodies for Escherichia coli and Salmonella enterica serovar Typhimurium cells were immobilized on the magnetic beads via glutaraldehyde coupling reaction. Our IMS system successfully separated Salmonella cells when the concentrations of target (i.e., Salmonella) and interfering (i.e., E. coli) cells were at the same level. Polymerase chain reaction (PCR) assays amplifying the rfb/rfbE region of the E. coli genome and a 647-bp fragment of the invA region of Salmonella were performed as the specific selection to accurately confirm the presence of E. coli and Salmonella, respectively. IMS and multiplex PCR methods can be used for specific and quantitative detection of pathogens from food samples. Thus, this study developed a reliable and direct system for rapid detection of Salmonella and E. coli in food samples. In addition, IMS method could be easily adapted to detect other pathogens by selecting the pertinent antibody. PMID:24048640

Ozalp, V Cengiz; Bayramoglu, Gulay; Arica, M Yakup; Oktem, H Avni

2013-09-19

265

Building on the Common Core  

ERIC Educational Resources Information Center

|The Common Core State Standards, released in June 2010, offer an opportunity to shift education away from shallow, test-prep instruction and toward a focus on key cognitive skills, writes Conley. Two consortia of states are now developing common assessments to measure these standards--assessments that will be designed to capture deeper, more…

Conley, David T.

2011-01-01

266

A Common Core of Readiness  

ERIC Educational Resources Information Center

|The common core state standards, which have now been adopted by 46 states and the District of Columbia, were designed around the goal of ensuring college and career readiness for all students. In this article, Rothman discusses research showing that a large proportion of U.S. high school graduates are ill-prepared to succeed in college or a…

Rothman, Robert

2012-01-01

267

Suspended-core fibers for sensing applications  

NASA Astrophysics Data System (ADS)

A brief review on suspended-core fibers for sensing applications is presented. A historical overview over the previous ten years about this special designed microstructure optical fiber is described. This fiber presents attractive optical properties for chemical/biological or gas measurement, but it can be further explored for alternative sensing solutions, namely, in-fiber interferometers based on the suspended-core or suspended-multi-core fiber, for physical parameter monitoring.

Frazão, Orlando; Silva, Ricardo M.; Ferreira, Marta S.; Santos, José L.; Lobo Ribeiro, António B.

2012-06-01

268

Identifying Core Habitat and Connectivity for Focal Species in the Interior Cedar-Hemlock Forest of North America to Complete a Conservation Area Design  

Microsoft Academic Search

To identify the remaining areas of the Interior Cedar-Hemlock Forest of North America and prioritize them for conservation planning, the Craighead Environmental Research Institute has developed a 2-scale method for mapping critical habitat utilizing 1) a broad-scale model to identify important regional locations as the basis for a Conservation Area Design (CAD), and 2) fine-scale models for analyzing habitat quality

Lance Craighead; Baden Cross

269

Design and Implementation of the Navigation Co-scheduling System for the Three Gorges-Gezhouba Dams with Core J2EE Patterns  

Microsoft Academic Search

As the Three Gorges Dam has put into operation, it is necessary to develop a co-scheduling navigation system for both the Three Gorges Dam and the Gezhouba Dam. The navigation co-scheduling system for the Three Gorges-Gezhouba Dams aims at ensuring safe, convenient and smooth navigation of the ships passing through both dams. The design and implementation of the navigation co-scheduling

Liang Zeng; Huan Qi; Xiao-Ping Wang; Heng-Hui Xiao; Ying-Chun Chen; Xiao-Pan Zhang

2006-01-01

270

Post Impact Behavior of Mobile Reactor Core Containment Systems.  

National Technical Information Service (NTIS)

The reactor core containment vessel temperatures after impact, and the design variables that affect the post impact survival of the system are analyzed. The heat transfer analysis includes conduction, radiation, and convection in addition to the core mate...

R. L. Puthoff W. G. Parker L. E. Vanbibber

1972-01-01

271

Liquid sodium model of geophysical core convection  

Microsoft Academic Search

Convective motions in Earth's outer core are responsible for the generation of the geomagnetic field. We present liquid sodium convection experiments in a spherical vessel, designed to model the convective state of planetary cores such as the Earth's. Heat transfer, azimuthal fluid velocities, and properties of temperature fluctuations were measured for different rotation rates and temperature drops across the convecting

Woodrow L. Shew; Daniel P. Lathrop

2005-01-01

272

Liquid sodium model of geophysical core convection  

Microsoft Academic Search

Convective motions in Earth’s outer core are responsible for the generation of the geomagnetic field. We present liquid sodium convection experiments in a spherical vessel, designed to model the convective state of planetary cores such as the Earth’s. Heat transfer, azimuthal fluid velocities, and properties of temperature fluctuations were measured for different rotation rates and temperature drops across the convecting

Woodrow L. Shew; Daniel P. Lathrop

2005-01-01

273

Liquid sodium model of Earth's outer core  

Microsoft Academic Search

Convective motions in Earth's outer core are responsible for the generation of the geomagnetic field. We present liquid sodium convection experiments in a spherical vessel, designed to model the convective state of Earth's outer core. Heat transfer, zonal fluid velocities, and properties of temperature fluctuations were measured for different rotation rates O and temperature drops DeltaT across the convecting sodium.

Woodrow Shew

2004-01-01

274

Effect of electrical steel grade on transformer core audible noise  

NASA Astrophysics Data System (ADS)

The effect of different core material grades (M4, MOH and ZDKH) on noise level was investigated experimentally on single-phase dry-type transformer models. Two types of core design were used (conventional mitred overlapping and step-lap overlapping). The models with MOH and ZDKH material have roughly the same noise levels. The models with M4 grade material have higher noise levels than those with MOH or ZDKH, but the difference depends on core induction and core design.

Valkovic, Z.

1994-05-01

275

The Ensembl Core Software Libraries  

PubMed Central

Systems for managing genomic data must store a vast quantity of information. Ensembl stores these data in several MySQL databases. The core software libraries provide a practical and effective means for programmers to access these data. By encapsulating the underlying database structure, the libraries present end users with a simple, abstract interface to a complex data model. Programs that use the libraries rather than SQL to access the data are unaffected by most schema changes. The architecture of the core software libraries, the schema, and the factors influencing their design are described. All code and data are freely available.

Stabenau, Arne; McVicker, Graham; Melsopp, Craig; Proctor, Glenn; Clamp, Michele; Birney, Ewan

2004-01-01

276

Magnetic-Core and Air-Core Inductors on Silicon: A Performance Comparison up to 100 MHz  

Microsoft Academic Search

What is the future of integrated inductor design on silicon for power conversion applications at frequencies up to 100 MHz—is it magnetic-core or air-core inductors. This study presents measured results for two microfabricated inductors (magnetic core and air core), which have been designed to operate at 20 MHz and occupy a substrate area of less than 10 . The inductor

Ronan Meere; Ningning Wang; Terence O'Donnell; Santosh Kulkarni; Saibal Roy; S. Cian O'Mathuna

2011-01-01

277

NEUTRONIC REACTOR CORE  

DOEpatents

An improved core for a gas-cooled power reactor which admits gas coolant at high temperatures while affording strong integral supporting structure and efficient moderation of neutrons is described. The multiplicities of fuel elements constituting the critical amassment of fissionable material are supported and confined by a matrix of metallic structure which is interspersed therebetween. Thermal insulation is interposed between substantially all of the metallic matrix and the fuel elements; the insulation then defines the principal conduit system for conducting the coolant gas in heat-transfer relationship with the fuel elements. The metallic matrix itseif comprises a system of ducts through which an externally-cooled hydrogeneous liquid, such as water, is circulated to serve as the principal neutron moderant for the core and conjointly as the principal coolant for the insulated metallic structure. In this way, use of substantially neutron transparent metals, such as aluminum, becomes possible for the supporting structure, despite the high temperatures of the proximate gas. The Aircraft Nuclear Propulsion program's "R-1" reactor design is a preferred embodiment.

Thomson, W.B.; Corbin, A. Jr.

1961-07-18

278

A DSP core for speech coding applications  

Microsoft Academic Search

An application specific processor core for mobile speech coding applications has been designed and implemented. Since the architecture is tailored to the application, it has a very low power consumption, making it attractive for handheld devices. The low power consumption, flexible design and high performance have been achieved by a standby mode, optimized full custom design, and a low clock

J. Nurmi; V. Eerola; E. Ofner; A. Gierlinger; J. Jernej; T. Karema; T. Raita-aho

1994-01-01

279

Design of meso-TiO2@MnOx-CeOx/CNTs with a core-shell structure as DeNOx catalysts: promotion of activity, stability and SO2-tolerance.  

PubMed

Developing low-temperature deNOx catalysts with high catalytic activity, SO2-tolerance and stability is highly desirable but remains challenging. Herein, by coating the mesoporous TiO2 layers on carbon nanotubes (CNTs)-supported MnOx and CeOx nanoparticles (NPs), we obtained a core-shell structural deNOx catalyst with high catalytic activity, good SO2-tolerance and enhanced stability. Transmission electron microscopy, X-ray diffraction, N2 sorption, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction and NH3 temperature-programmed desorption have been used to elucidate the structure and surface properties of the obtained catalysts. Both the specific surface area and chemisorbed oxygen species are enhanced by the coating of meso-TiO2 sheaths. The meso-TiO2 sheaths not only enhance the acid strength but also raise acid amounts. Moreover, there is a strong interaction among the manganese oxide, cerium oxide and meso-TiO2 sheaths. Based on these favorable properties, the meso-TiO2 coated catalyst exhibits a higher activity and more extensive operating-temperature window, compared to the uncoated catalyst. In addition, the meso-TiO2 sheaths can serve as an effective barrier to prevent the aggregation of metal oxide NPs during stability testing. As a result, the meso-TiO2 overcoated catalyst exhibits a much better stability than the uncoated one. More importantly, the meso-TiO2 sheaths can not only prevent the generation of ammonium sulfate species from blocking the active sites but also inhibit the formation of manganese sulfate, resulting in a higher SO2-tolerance. These results indicate that the design of a core-shell structure is effective to promote the performance of deNOx catalysts. PMID:23970126

Zhang, Lei; Zhang, Dengsong; Zhang, Jianping; Cai, Sixiang; Fang, Cheng; Huang, Lei; Li, Hongrui; Gao, Ruihua; Shi, Liyi

2013-09-26

280

NFE Core Bibliographies.  

National Technical Information Service (NTIS)

This collection of core bibliographies, which expands on an initial bibliography published in 1979 of the core resources housed in the Non-Formal Education Information Center at Michigan State University, comprises a basic stock of materials on nonformal ...

1981-01-01

281

On the performance of truss panels with Kagomé cores  

Microsoft Academic Search

The performance characteristics of a truss core sandwich panel design based on the 3D Kagomé has been measured and compared with earlier simulations. Panels have been fabricated by investment casting and tested in compression, shear and bending. The isotropic nature of this core design has been confirmed. The superior performance relative to truss designs based on the tetrahedron has been

J. Wang; A. G. Evans; K. Dharmasena; H. N. G. Wadley

2003-01-01

282

Core Competence and Education.  

ERIC Educational Resources Information Center

|Outlines the concept of core competence and applies it to postcompulsory education in the United Kingdom. Adopts an educational perspective that suggests accreditation as the core competence of universities. This economic approach suggests that the market trend toward lifetime learning might best be met by institutions developing a core

Holmes, Gary; Hooper, Nick

2000-01-01

283

Processing of Activated Core Components  

SciTech Connect

Used activated components from the core of a NPP like control elements, water channels from a BWR, and others like in-core measurement devices need to be processed into waste forms suitable for interim storage, and for the final waste repository. Processing of the activated materials can be undertaken by underwater cutting and packaging or by cutting and high-pressure compaction in a hot cell. A hot cell is available in Germany as a joint investment between GNS and the Karlsruhe Research Center at the latter's site. Special transport equipment is available to transport the components ''as-is'' to the hot cell. Newly designed underwater processing equipment has been designed, constructed, and operated for the special application of NPP decommissioning. This equipment integrates an underwater cutting device with an 80 ton force underwater in-drum compactor.

Friske, A.; Gestermann, G.; Finkbeiner, R.

2003-02-26

284

Lifecycle diagnoses of real estate enterprise's core competence  

Microsoft Academic Search

Core competence of real estate enterprise is the fountain and impetus that real estate enterprises obtain sustainable competitive advantage. Strategic decision capability, construction & production capability, design & planning capability, organizational and interface management capability, marketing competence are five dimensions those made up for a real estate enterprise's core competence. From above five dimensions, a real estate enterprise's core competence

Li Yulong; Sun Ping

2011-01-01

285

On backfitting engineering safety features to mitigate core melt accidents  

Microsoft Academic Search

In October 1980, the Nuclear Regulatory Commission published its intent to initiate rulemaking, to consider to what extent, if any, nuclear power plants should be designed to deal effectively with degraded core and core melt accidents. This paper focuses on the issues surrounding the proposed rulemaking for consideration of degraded cores. It is intended to provide a short historical perspective,

Kastenberg

1982-01-01

286

Core performance tests for the JOYO MK-III upgrade  

Microsoft Academic Search

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

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

2007-01-01

287

Active Barnase Variants with Completely Random Hydrophobic Cores  

Microsoft Academic Search

The central structural feature of natural proteins is a tightly packed and highly ordered hydrophobic core. If some measure of exquisite, native-like core packing is necessary for enzymatic function, this would constitute a significant obstacle to the development of novel enzymes, either by design or by natural or experimental evolution. To test the minimum requirements for a core to provide

Douglas D. Axe; Nicholas W. Foster; Alan R. Fersht

1996-01-01

288

Core Stability: Inter and Intraobserver Reliability of 6 Clinical Tests  

Microsoft Academic Search

Objective: Core stability is a complex concept within sports medicine and is thought to play a role in sports injuries. There is a lack of reliable and valid clinical tests for core stability. The inter- and intraobserver reliability of 6 tests commonly used to assess core stability was determined. Design: A video of the tests was shown to 6 observers.

Adam Weir; Jennifer Darby; Han Inklaar; Bart Koes; Erik Bakker; Johannes L Tol

2010-01-01

289

Ice Core Secrets  

NSDL National Science Digital Library

In this activity, students will explore the characteristics of ice and explain the influencing factors by using Internet connections to polar field experiences, making their own ice cores and taking a field trip for obtaining a local ice core. The students will practice scientific journaling to document their observations. They will assemble their findings, develop a poster of their ice core and explain their observations. The 'ice is ice' misconception will be dispelled. Students will explain what scientists learn from ice cores and define basic vocabulary associated with ice cores.

Kolb, Sandra

290

Core-Melt Source Reduction System (COMSORS) to terminate LWR core-melt accidents  

Microsoft Academic Search

One of the design, safety, and licensing issues for the next generation of light-water reactors is this: What approach should be used to terminate a reactor core-melt accident and ensure no reactor containment failure in the unlikely event of an accident that results in core debris upon the containment floor The safety concerns are that the debris will (1) melt

C. W. Forsberg; E. C. Beahm; G. W. Parker

1992-01-01

291

Core-Melt Source Reduction System (COMSORS) to terminate LWR core-melt accidents  

Microsoft Academic Search

One of the design, safety, and licensing issues for the next generation of light-water reactors is this: What approach should be used to terminate a reactor core-melt accident and ensure no reactor containment failure in the unlikely event of an accident that results in core debris upon the containment floor? The safety concerns are that the debris will (1) melt

C. W. Forsberg; E. C. Beahm; G. W. Parker

1992-01-01

292

Core-melt source reduction system to terminate an LWR core-melt accident  

Microsoft Academic Search

One of the design, safety, and licensing issues for the next generation of light water reactors (LWRs) is, [open quotes]What approach should be used to terminate a reactor core-melt accident and ensure no reactor containment failure in the unlikely event of an accident that results in core debris melting through the reactor vessel onto the concrete containment floor [close quotes

C. W. Forsberg; E. C. Beahm; G. W. Parker

1992-01-01

293

Dynamic response of cylindrical ACS support structures to core energy release. [Above-core structures  

SciTech Connect

The code SAFE/RAS is applied to the analysis of a new design concept for the above-core structures when subjected to the loads of a core disruptive accident. The analysis involves the determination of the postbuckling response of a thin cylinder loaded both axially and vertically. The effects of variation of cylinder thickness and fluid-structure interaction are investigated.

Kennedy, J.M.; Belytschko, T.B.

1985-01-01

294

Development and analysis for core power gamma thermometer adaptation  

SciTech Connect

The gamma thermometer (GT) has gained increasing interest to replace the local power range monitor (LPRM) and the traversing in-core probe (TIP) as the core monitoring device in new boiling water reactor (BWR) designs. The number of GTs is designed between the number of LPRMs, 4, and the number of TIPs, 24, per string, but its optimal number is yet to be determined. The authors have modified the BWR core Simulator PANACEA for analyzing the core power GT adaptation and have compared the axial core-averaged relative power distributions and two thermal limits of the GT 8- and 12-point adaptations against those of the TIP 24-point adaptation.

Ren-Tai Chiang; Leong, T. [General Electric Co., San Jose, CA (United States)

1996-12-31

295

Ice Core Dating Software for Interactive Dating of Ice Cores  

NASA Astrophysics Data System (ADS)

Scientists involved in ice core dating are well familiar with the problem of identification and recording the depth of annual signals using stable isotopes, glaciochemistry, ECM (electrical conductivity), DEP (dielectric properties) and particle counter data. Traditionally all parameters used for ice core dating were plotted as a function of depth, printed and after years were marked on the paper, converted to depth vs. age time scale. To expedite this tedious and manual process we developed interactive computer software, Ice core Dating (ICD) program. ICD is written in Java programming language, and uses GPL and GPL site licensed graphic libraries. The same 3.5 Mb in size pre-compiled single jar file, that includes all libraries and application code, was successfully tested on WinOS, Mac OSX, Linux, and Solaris operating systems running Java VM version 1.4. We have followed the modular design philosophy in our source code so potential integration with other software modules, data bases and server side distributed computer environments can be easily implemented. We expect to continue development of new suites of tools for easy integration of ice core data with other available time proxies. ICD is thoroughly documented and comes with a technical reference and cookbook that explains the purpose of the software and its many features, and provides examples to help new users quickly become familiar with the operation and philosophy of the software. ICD is available as a free download from the Climate Change Institute web site ( under the terms of GNU GPL public license.

Kurbatov, A. V.; Mayewski, P. A.; Abdul Jawad, B. S.

2005-12-01

296

Multi Core Design for Chip Level Multiprocessing  

NASA Astrophysics Data System (ADS)

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.

Fossum, Tryggve

297

The identification of the 2-phenylphthalazin-1(2H)-one scaffold as a new decorable core skeleton for the design of potent and selective human A3 adenosine receptor antagonists.  

PubMed

Following a molecular simplification approach, we have identified the 2-phenylphthalazin-1(2H)-one (PHTZ) ring system as a new decorable core skeleton for the design of novel hA(3) adenosine receptor (AR) antagonists. Interest for this new series was driven by the structural similarity between the PHTZ skeleton and both the 2-aryl-1,2,4-triazolo[4,3-a]quinoxalin-1-one (TQX) and the 4-carboxamido-quinazoline (QZ) scaffolds extensively investigated in our previously reported studies. Our attention was focused at position 4 of the phthalazine nucleus where different amido and ureido moieties were introduced (compounds 2-20). Some of the new PHTZ compounds showed high hA(3) AR affinity and selectivity, the 2,5-dimethoxyphenylphthalazin-1(2H)-one 18 being the most potent and selective hA(3) AR antagonist among this series (K(i) = 0.776 nM; hA(1)/hA(3) and hA(2A)/hA(3) > 12000). Molecular docking studies on the PHTZ derivatives revealed for these compounds a binding mode similar to that of the previously reported TQX and QZ series, as was expected from the simplification approach. PMID:21401121

Poli, Daniela; Catarzi, Daniela; Colotta, Vittoria; Varano, Flavia; Filacchioni, Guido; Daniele, Simona; Trincavelli, Letizia; Martini, Claudia; Paoletta, Silvia; Moro, Stefano

2011-03-14

298

Double-core GMI current sensor  

Microsoft Academic Search

A novel design of the giant magnetoimpedance contactless current sensor is presented. A double-core structure is used in order to improve the temperature stability. The temperature coefficient of sensitivity and offset drift are reduced to one-half compared to the single-core sensor. The linearity error decreases by a factor of three. Further utilization of an ac biasing (up to 200 Hz)

Michal Malátek; Pavel Ripka; L. Kraus

2005-01-01

299

Understanding the Memory Behavior of Emerging Multi-core Workloads  

Microsoft Academic Search

This paper characterizes the memory behavior on emerging RMS (recognition, mining, and synthesis) workloads for future multi-core processors. As multi-core processors proliferate across different application domains, and the number of on-die cores continues to increase, a key issue facing processor architects is the design of the on-die last level cache (LLC). In this paper, we explore the LLC design space

Junmin Lin; Yu Chen; Wenlong Li; Aamer Jaleel; Zhizhong Tang

2009-01-01

300

The core to regulatory reform  

SciTech Connect

Federal Energy Regulatory Commission (FERC) Orders 436, 500, and 636, the Clean Air Act Amendments of 1990, Public Utility Holding Company Act reform, and the 1992 Energy Policy Act all can have significant effects on an LDC's operations. Such changes in an LDC's environments must be balanced by changes within the utility, its marketplace, and its state regulatory environment. The question is where to start. For Columbia Gas Distribution Cos., based in Columbus, OH, the new operating foundation begins with each employee. Internal strength is critical in designing initiatives that meet the needs of the marketplace and are well-received by regulators. Employees must understand not only the regulatory environment in which the LDC operates, but also how their work contributes to a positive regulatory relationship. To achieve this, Columbia initiated the COntinuing Regulatory Education program, or CORE, in 1991. CORE is a regulatory-focused, information-initiative program coordinated by Columbia's Regulatory Policy, Planning, and Government Affairs Department. The CORE programs can take many forms, such as emerging issue discussions, dialogues with regulators and key parties, updates on regulatory fillings, regulatory policy meetings, and formal training classes. The speakers and discussion facilitators can range from human resource department trainers to senior officers, from regulatory department staff members to external experts, or from state commissioners to executives from other LDCs. The goals of CORE initiatives are to: Support a professional level of regulatory expertise through employee participation in well-developed regulatory programs presented by credible experts. Encourage a constructive state regulatory environment founded on communication and cooperation. CORE achieves these goals via five program levels: introductory basics, advanced learning, professional expertise, crossfunctional dialogues, and external idea exchanges.

Partridge, J.W. Jr.

1993-06-15

301

Design of meso-TiO2@MnOx-CeOx/CNTs with a core-shell structure as DeNOx catalysts: promotion of activity, stability and SO2-tolerance  

NASA Astrophysics Data System (ADS)

Developing low-temperature deNOx catalysts with high catalytic activity, SO2-tolerance and stability is highly desirable but remains challenging. Herein, by coating the mesoporous TiO2 layers on carbon nanotubes (CNTs)-supported MnOx and CeOx nanoparticles (NPs), we obtained a core-shell structural deNOx catalyst with high catalytic activity, good SO2-tolerance and enhanced stability. Transmission electron microscopy, X-ray diffraction, N2 sorption, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction and NH3 temperature-programmed desorption have been used to elucidate the structure and surface properties of the obtained catalysts. Both the specific surface area and chemisorbed oxygen species are enhanced by the coating of meso-TiO2 sheaths. The meso-TiO2 sheaths not only enhance the acid strength but also raise acid amounts. Moreover, there is a strong interaction among the manganese oxide, cerium oxide and meso-TiO2 sheaths. Based on these favorable properties, the meso-TiO2 coated catalyst exhibits a higher activity and more extensive operating-temperature window, compared to the uncoated catalyst. In addition, the meso-TiO2 sheaths can serve as an effective barrier to prevent the aggregation of metal oxide NPs during stability testing. As a result, the meso-TiO2 overcoated catalyst exhibits a much better stability than the uncoated one. More importantly, the meso-TiO2 sheaths can not only prevent the generation of ammonium sulfate species from blocking the active sites but also inhibit the formation of manganese sulfate, resulting in a higher SO2-tolerance. These results indicate that the design of a core-shell structure is effective to promote the performance of deNOx catalysts.Developing low-temperature deNOx catalysts with high catalytic activity, SO2-tolerance and stability is highly desirable but remains challenging. Herein, by coating the mesoporous TiO2 layers on carbon nanotubes (CNTs)-supported MnOx and CeOx nanoparticles (NPs), we obtained a core-shell structural deNOx catalyst with high catalytic activity, good SO2-tolerance and enhanced stability. Transmission electron microscopy, X-ray diffraction, N2 sorption, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction and NH3 temperature-programmed desorption have been used to elucidate the structure and surface properties of the obtained catalysts. Both the specific surface area and chemisorbed oxygen species are enhanced by the coating of meso-TiO2 sheaths. The meso-TiO2 sheaths not only enhance the acid strength but also raise acid amounts. Moreover, there is a strong interaction among the manganese oxide, cerium oxide and meso-TiO2 sheaths. Based on these favorable properties, the meso-TiO2 coated catalyst exhibits a higher activity and more extensive operating-temperature window, compared to the uncoated catalyst. In addition, the meso-TiO2 sheaths can serve as an effective barrier to prevent the aggregation of metal oxide NPs during stability testing. As a result, the meso-TiO2 overcoated catalyst exhibits a much better stability than the uncoated one. More importantly, the meso-TiO2 sheaths can not only prevent the generation of ammonium sulfate species from blocking the active sites but also inhibit the formation of manganese sulfate, resulting in a higher SO2-tolerance. These results indicate that the design of a core-shell structure is effective to promote the performance of deNOx catalysts. Electronic supplementary information (ESI) available: EDS analysis of MnCe/CNTs, XPS spectrum of meso-TiO2@MnCe/CNTs and TEM images of the catalysts after stability test. See DOI: 10.1039/c3nr03150k

Zhang, Lei; Zhang, Dengsong; Zhang, Jianping; Cai, Sixiang; Fang, Cheng; Huang, Lei; Li, Hongrui; Gao, Ruihua; Shi, Liyi

2013-09-01

302

Validation of an Advanced Encryption Standard (AES) IP Core  

Microsoft Academic Search

This paper describes the package of test bench code required to verify the Algotronix' AES IP Core. Several authors (see the references in (3)) have published papers detailing the implementation of the Advanced Encryption Standard (AES) on FPGA chips; however, the design goals of this AES core are somewhat different from previous work. Rather than emphasizing performance our design emphasizes

Valeri F. Tomashau; Tom Kean

2004-01-01

303

Core melt spreading on a reactor containment floor  

Microsoft Academic Search

The ex-vessel core melt spreading, cooling and stabilization is proposed for a nuclear power plant containment design. Clearly, the retention and coolability of the decay-heated core debris is very much the focal point in the proposed new and advanced designs so that, in the postulated event of a severe accident, the containment integrity is maintained and the risk of radioactivity

T. N Dinh; M. J Konovalikhin; B. R Sehgal

2000-01-01

304

Ice Core Investigations  

NSDL National Science Digital Library

What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice Core Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice core drilling, and air pollution to create a meaningful science learning experience for students.

Krim, Jessica; Brody, Michael

2008-09-01

305

Cores of convex games  

Microsoft Academic Search

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.

Lloyd S. Shapley

1971-01-01

306

Ice Core Investigations  

ERIC Educational Resources Information Center

|What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice Core Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice core drilling, and air…

Krim, Jessica; Brody, Michael

2008-01-01

307

NFE Core Bibliographies.  

ERIC Educational Resources Information Center

|This collection of core bibliographies, which expands on an initial bibliography published in 1979 of the core resources housed in the Non-Formal Education Information Center at Michigan State University, comprises a basic stock of materials on nonformal education and women in development that have been contributed by development planners,…

Michigan State Univ., East Lansing. Inst. for International Studies in Education.

308

Making an Ice Core.  

ERIC Educational Resources Information Center

|Explains an activity in which students construct a simulated ice core. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice cores are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)|

Kopaska-Merkel, David C.

1995-01-01

309

MAGNOX CORE PERFORMANCE ANALYSIS  

Microsoft Academic Search

A single-point model is developed to represent the performance of Magnox ; cores on the assumptions that maximum channel output is independent of coolant ; flow and temperatures. Using the basic geometry and temperature data, specified ; comparisons of six U.K. power reactors are made. Minimization computations are ; also carried out for the uranium inventory of reactor cores of

R. E. Strickland; D. J. McConalogue

1962-01-01

310

The Earth's Core: How Does It Work? Perspectives in Science. Number 1.  

ERIC Educational Resources Information Center

|Various research studies designed to enhance knowledge about the earth's core are discussed. Areas addressed include: (1) the discovery of the earth's core; (2) experimental approaches used in studying the earth's core (including shock-wave experiments and experiments at high static pressures), the search for the core's light elements, the…

Carnegie Institution of Washington, Washington, DC.

311

Dynamics of Core Accretion  

NASA Astrophysics Data System (ADS)

In this poster, we discuss the dynamical behavior of gas flowing around a core of mass Mc=10me that is embedded in a near Keplerian background flow. We find that the flow is characterized by a strong `flip-flop' behavior and no static envelope forms. Over the course of the simulation the amount of mass surrounding the core is roughly constant, but the varying flow pattern gives rise to regular and large `eruptions' of matter from the region around the core which return matter to the background flow: mass in the envelope at one time is not found in the envelope at any later time.

Nelson, A. F.; Ruffert, M. O.

2004-12-01

312

Core shroud corner joints  

DOEpatents

A core shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the core shroud. Four quarter perimeter segments join together to form the core shroud.

Gilmore, Charles B.; Forsyth, David R.

2013-09-10

313

Liquid core integrated ring resonator  

NASA Astrophysics Data System (ADS)

We report the design and the fabrication of an integrated optofluidic ring resonator based on liquid core antiresonant reflecting optical waveguide (ARROW) operating around ?=635nm with a water filled core (nc=1.33). This waveguide permits a strong coupling between light and analyte as the same microchannel can be used for delivering sample and for confining light. A rectangular-shaped ring resonator has been realized by using four 90-bent waveguides and an multimode interference coupler is used for coupling light from the input bus waveguide to the resonator. The resulting device is very compact, with a total length of 2.5 mm and a required liquid volume of about 0.11nl. The device has been simulated with a two dimensional finite-difference time-domain method for different refractive index core nc=1.32 (methanol) and nc=1.43 (dimethylformamide). Moreover, we carried out optical measurements by measuring the transmitted spectrum from the output bus waveguide in both cases. The experimental results confirm that ring with a good quality factor (Q~800) can be achieved in good agreement with the numerical results.

Testa, Genni; Huang, Yujian; Zeni, Luigi; Sarro, Pasqualina M.; Bernini, Romeo

2011-02-01

314

Structural Performance of Eco-Core Sandwich Panels  

NASA Astrophysics Data System (ADS)

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.

Shivakumar, Kunigal; Chen, Huanchun

315

Starting a TALEN Core Facility  

PubMed Central

Targeted gene modifications have been advanced by the use of engineered nucleases that make a double strand break (DSB) in genomic DNA. When the cell responds to the DSB by either the imperfect repair process of non-homologous end joining (NHEJ) or by homologous recombination (HR) from a donor template, a targeted modification can result. Since the first engineered nucleases were made in 1996 by fusing a zinc finger DNA binding domain to a FokI cleavage domain, Zinc Finger Nucleases (ZFNs) have progressed considerably to the point of clinical trials for HIV. More recently in 2009, a DNA binding motif called Transcription Activator Like Effector (TALE) was discovered to have a simple code for sequence recognition. Using the same concept as in ZFNs, TALEs were fused to a FokI cleavage domain to engineer Transcription Activator Like Effector Nucleases (TALENs). Although ZFNs are several years ahead of TALENs on research and optimization, TALENs are quickly proving to be capable of similar performance but with a much simpler design. There are commercial vendors as well as core facilities producing ZFNs and TALENs and multiple TALEN assembly kits that have been made publicly available. These TALEN assembly kits can be used to construct a custom nuclease for virtually any genome region of interest. With the idea of starting a TALEN core facility service for a private institution, a comparison of the assembly methods was made to determine which method was best suited. This presentation will introduce the TALEN structure, compare assembly methods from a core facility perspective and highlight the first experiences of starting a TALEN core facility.

Delventhal, Kym

2013-01-01

316

Separated Core Turbofan Engine.  

National Technical Information Service (NTIS)

A new concept for a turbofan engine called the 'Separated Core Turbofan Engine' is proposed and studied under the research program of the ultrahigh bypass turbofan engine for the next generation high-subsonic transport aircraft. The concept engine consist...

Y. Saito M. Endoh Y. Matsuda N. Sugiyama N. Sugahara K. Yamamoto

1996-01-01

317

Core assembly storage structure  

DOEpatents

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.

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

1988-01-01

318

Replaceable LMFBR Core Components.  

National Technical Information Service (NTIS)

Much progress has been made in understanding material and component performance in the high temperature, fast neutron environment of the LMFBR. Current data have provided strong assurance that the initial core component lifetime objectives of FFTF and CRB...

E. A. Evans G. W. Cunningham

1976-01-01

319

EXPOSURE ASSESSMENT FACILITY CORE  

EPA Science Inventory

The Exposure Assessment Facility Core will continue to collect environmental measures including personal and indoor air monitoring and repeat collection of dust samples from the home and biologic measures including urine and blood samples collected from the mother during pregn...

320

Guidelines for Core Measures.  

National Technical Information Service (NTIS)

Contents: Introduction; Overview; At A Glance; Why Measure Program Impact; Principles of Measurement (Selecting core measures for administration, Substitutions and Supplements, Regulatory and legal matters, Measurement is a science, scheduling measurement...

1999-01-01

321

Core level electron diffraction.  

National Technical Information Service (NTIS)

In this article the basic elements of the theory of core level electron diffraction are given in a comprehensive form. All relevant formulas are obtained rigorously. Some approximations are then considered such as those involving single scatterings and pl...

L. Fonda

1993-01-01

322

Nuclear core positioning system  

DOEpatents

A structural support system for the core of a nuclear reactor which achieves relatively restricted clearances at operating conditions and yet allows sufficient clearance between fuel assemblies at refueling temperatures. Axially displaced spacer pads having variable between pad spacing and a temperature compensated radial restraint system are utilized to maintain clearances between the fuel elements. The core support plates are constructed of metals specially chosen such that differential thermal expansion produces positive restraint at operating temperatures.

Garkisch, Hans D. (Irwin, PA); Yant, Howard W. (Greensburg, PA); Patterson, John F. (Murrysville, PA)

1979-01-01

323

Understanding Core Data  

Microsoft Academic Search

\\u000a Many developers, upon first seeing Core Data, deem Core Data and its classes a tangled mess of classes that impede, rather\\u000a than enhance, data access. Perhaps they’re Rails developers, used to making up method names to create dynamic finders and\\u000a letting convention over configuration take care of the dirty work of data access. Maybe they’re Java developers who have been

Michael Privat; Rob Warner

324

Comparison of different iron core models of three-phase core-type transformers  

Microsoft Academic Search

Purpose – The majority of three-phase dynamic transformer models used in commercially available electric power system transient simulation programs offer only saturated three-phase transformer models built from three single-phase transformer models. This paper sets out to deal with the modelling and transient analysis of a saturated three-limb core-type transformer. Design\\/methodology\\/approach – Three iron core models I-III are given by the

Matjaž Dolinar; Drago Dolinar; Gorazd Štumberger; Boštjan Polajžer

2007-01-01

325

Power flattening options for the ENHS (encapsulated nuclear heat source) core  

Microsoft Academic Search

The feasibility of power flattening while maintaining a nearly constant keff over the core life is assessed for the Encapsulated Nuclear Heat Source (ENHS). A couple of approaches are considered — using different fuel dimensions and using different enrichment levels across the core. Three new cores with flattened power distribution are successfully designed: Design-I uses different fuel rod diameters but

Ser Gi Hong; Ehud Greenspan

2005-01-01

326

Approaches for achieving very high core outlet temperatures in prismatic modular helium reactors  

Microsoft Academic Search

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

M. LaBar; M. Richards; A. Shenoy

2004-01-01

327

Heuristic rules embedded genetic algorithm for in-core fuel management optimization  

Microsoft Academic Search

The objective of this study was to develop a unique methodology and a practical tool for designing loading pattern (LP) and burnable poison (BP) pattern for a given Pressurized Water Reactor (PWR) core. Because of the large number of possible combinations for the fuel assembly (FA) loading in the core, the design of the core configuration is a complex optimization

Fatih Alim

2006-01-01

328

Core-shell nanostructured catalysts.  

PubMed

Novel nanotechnologies have allowed great improvements in the syn-thesis of catalysts with well-controlled size, shape, and surface properties. Transition metal nanostructures with specific sizes and shapes, for instance, have shown great promise as catalysts with high selectivities and relative ease of recycling. Researchers have already demonstrated new selective catalysis with solution-dispersed or supported-metal nanocatalysts, in some cases applied to new types of reactions. Several challenges remain, however, particularly in improving the structural stability of the catalytic active phase. Core-shell nanostructures are nanoparticles encapsulated and protected by an outer shell that isolates the nanoparticles and prevents their migration and coalescence during the catalytic reactions. The synthesis and characterization of effective core-shell catalysts has been at the center of our research efforts and is the focus of this Account. Efficient core-shell catalysts require porous shells that allow free access of chemical species from the outside to the surface of nanocatalysts. For this purpose, we have developed a surface-protected etching process to prepare mesoporous silica and titania shells with controllable porosity. In certain cases, we can tune catalytic reaction rates by adjusting the porosity of the outer shell. We also designed and successfully applied a silica-protected calcination method to prepare crystalline shells with high surface area, using anatase titania as a model system. We achieved a high degree of control over the crystallinity and porosity of the anatase shells, allowing for the systematic optimization of their photocatalytic activity. Core-shell nanostructures also provide a great opportunity for controlling the interaction among the different components in ways that might boost structural stability or catalytic activity. For example, we fabricated a SiO2/Au/N-doped TiO2 core-shell photocatalyst with a sandwich structure that showed excellent catalytic activity for the oxidation of organic compounds under UV, visible, and direct sunlight. The enhanced photocatalytic efficiency of this nanostructure resulted from an added interfacial nonmetal doping, which improved visible light absorption, and from plasmonic metal decoration that enhanced light harvesting and charge separation. In addition to our synthetic efforts, we have developed ways to evaluate the accessibility of reactants to the metal cores and to characterize the catalytic properties of the core-shell samples we have synthesized. We have adapted infrared absorption spectroscopy and titration experiments using carbon monoxide and other molecules as probes to study adsorption on the surface of metal cores in metal oxide-shell structures in situ in both gas and liquid phases. In particular, the experiments in solution have provided insights into the ease of diffusion of molecules of different sizes in and out of the shells in these catalysts. PMID:23268644

Zhang, Qiao; Lee, Ilkeun; Joo, Ji Bong; Zaera, Francisco; Yin, Yadong

2012-12-26

329

GRID-core: Gravitational potential identification of cores  

NASA Astrophysics Data System (ADS)

GRID-core is a core-finding method using the contours of the local gravitational potential to identify core boundaries. The GRID-core method applied to 2D surface density and 3D volume density are in good agreement for bound cores. We have implemented a version of the GRID-core algorithm in IDL, suitable for core-finding in observed maps. The required input is a two-dimensional FITS file containing a map of the column density in a region of a cloud.

Gong, Hao; Ostriker, Eve C.

2013-02-01

330

Health Care Assistant Core. Instructor Manual.  

ERIC Educational Resources Information Center

This document contains the core curriculum for a basic high school course for health care assistants. It is designed as a 1-semester course of study, after which students can take a course in an emphasis area, such as veterinary, nursing, pharmacology, or physical therapy, in which they learn skills for specific entry-level jobs. The curriculum…

Feilner, Veronica; Robling, Jeannine

331

First Core and Refueling Options for IRIS  

SciTech Connect

The International Reactor Innovative and Secure (IRIS) is being developed by an international consortium of industry, laboratory, university and utility establishments, led by Westinghouse. The IRIS design addresses key requirements associated with advanced reactors, including improved safety, enhanced proliferation resistance, competitive electricity production cost, and improved waste management. IRIS is a modular, small/medium size (100 to 335 MWe) PWR with integral vessel configuration. Its design is based on proven LWR technology, so that no new technology development is needed and near term deployment is possible. At the same time, aim was to introduce improvements as compared to present PWRs. These opposing requirements resulted in an evolutionary approach to fuel and core design, balancing new features and the need to avoid extensive testing and demonstration programs. A path forward was devised by selecting the current fuel technology for the first IRIS core, but keeping future upgrades possible through the variable moderation fuel assembly design. This paper describes this approach and discusses core fueling options that enable achieving four-year and eight-year core lifetime. (authors)

Petrovic, Bojan; Carelli, Mario D. [Westinghouse Electric Company (United States); Greenspan, Ehud; Milosevic, Miodrag; Vujic, Jasmina [Univ. California Berkeley, Berkeley CA 94720 (United States); Padovani, Enrico; Ganda, Francesco [Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milano (Italy)

2002-07-01

332

Core Skills and Transfer: Aiming High  

Microsoft Academic Search

Focusing particularly on the definition of ‘skill transfer’, this paper examines the relationship between research work on transfer and various curriculum initiatives designed to promote it. Competing theories and explanations of transfer are explored, and the paper suggests that many of the practical initiatives on core\\/transferable skills are under?theorised and require more thorough evaluation. The conclusion to the paper summarises

Tim Oates

1992-01-01

333

Thermal hydraulic model validation for HOR mixed core fuel management  

Microsoft Academic Search

A thermal-hydraulic core model has been developed for the Hoger Onderwijsreactor (HOR), a 2 MW pool-type research reactor. The model was adopted for safety analysis purposes in the framework of HEU\\/LEU (highly enriched uranium\\/low enriched uranium) core conversion studies. It is applied in the thermal-hydraulic computer code SHORT (Steady-state HOR Thermal-hydraulics) which is presently in use in designing core configurations

H. P. M Gibcus; J. W de Vries; P. F. A de Leege

1998-01-01

334

Smart System Using New Piezoelectric Fiber with Metal Core  

NASA Astrophysics Data System (ADS)

A new piezoelectric ceramic fiber containing a metal core was produced by the extrusion method. The insertion of a metal core is significant because the fiber's strength can be supported by the metal core which also serves as an internal electrode. A new smart board was designed by mounting these piezoelectric fibers into the surface of a CFRP composite. This smart composite board was able to both detect, and suppress vibrations.

Shimojo, Yoshiro; Sato, Hiroshi; Takagi, Kiyoshi; Shan, Yue Jin; Imoto, Hideo; Nagamine, Masaru

335

Bioinformatics Core Project Management  

PubMed Central

Bioinformatics cores that provide fee for service style support encounter a wide variety of projects. The scope of projects varies greatly among investigators. Because of this variety, it is difficult to develop a set of predefined services that fit all project types. While our own core has developed a baseline set of services, we found in practice these often needed significant modification to meet the goals of particular investigator. To overcome this problem we factored common features of all projects and partitioned them into groups: workflow management, data management, user results, and tracking and reporting. We then implemented best practices for each group using commercial and open source software combined with our own management policies. Finally we linked these areas together to produce an overall integrated project management solution that combines workflow management, data management, user results management and reporting capabilities. This system solves the problem of developing well defined services that are trackable and repeatable while simultaneously enabling flexibility that is easily managed. The result improves the effectiveness and efficiency of the bioinformatics core for scientists working within the core, for investigators receiving core support and for external auditors and evaluators.

Vangala, Mahesh; Vincent, James; Driscoll, Heather

2013-01-01

336

Testing Embedded-Core-Based System Chips  

Microsoft Academic Search

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

Yervant Zorian; Erik Jan Marinissen; Sujit Dey

1999-01-01

337

Framatome in-core instrumentation improvements  

SciTech Connect

Framatome TIA has successfully designed, manufactured, installed, and maintained the in-core instrumentation system (flux and temperature) for over 50 pressurized water reactors and a cumulative operating time of over three centuries in Europe, Asia, and Africa. The aim of Framatome's decision in 1968 to develop another system of flux measurement control rather than use the original licensed design was to avoid seal table leaks, reduce maintenance exposure, and improve system security.

Dunford, S.

1989-01-01

338

Formed Core Sampler Hydraulic Conductivity Testing  

SciTech Connect

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.

Miller, D. H.; Reigel, M. M.

2012-09-25

339

Twin-core fiber optical tweezers.  

PubMed

We present an abruptly tapered twin-core fiber optical tweezers, which is fabricated by fusing and drawing the twin-core fiber. In the twin-core fiber, the two beams are guided by the tapered fiber. At the end of the fiber tip, a larger converge angle between the two beams are made due to the abrupt tapered shape, which is formed a fast divergent optical field. The microscopic particle trapping performance of this special designed tapered twin-core fiber tip is investigated. The functionality of the proposed novel twin-core fiber optical tweezers is extended since an in-fiber integrated Mach-Zehnder interferometer has been used to control orientation of the trapped particle. The distribution of the optical field emerging from the tapered fiber tip is simulated based on the beam propagation method (BPM). By using this two-beam combination technique, a strong enough gradient forces well is obtained for microscopic particles trapping in three dimensions. The abruptly tapered twin-core fiber optical tweezers is rigid and easy to handle, especially useful for building up a multi-tweezers system for trapping and manipulating micro-scale particles. PMID:18542553

Yuan, Libo; Liu, Zhihai; Yang, Jun; Guan, Chunying

2008-03-31

340

Egalitarian solutions in the core  

Microsoft Academic Search

.   In this paper we define the Lorenz stable set, a subset of the core consisting of the allocations that are not Lorenz dominated by any other allocation of the core. We\\u000a introduce the leximin stable allocation, which is derived from the application of the Rawlsian criterion on the core. We also define and axiomatize the egalitarian core, a set

Javier Arin; Elena Inarra

2001-01-01

341

Languages and the Core Curriculum.  

ERIC Educational Resources Information Center

|Discusses the role of a core curriculum in language instruction in Australia. The semantics of "core curriculum" are treated. Arguments are given for methods of developing a core curriculum and for the inclusion of second language instruction in the core. Implications are discussed for language teaching and the educational system. (PJM)|

Ingram, D. E.

1980-01-01

342

Core Training: Stabilizing the Confusion  

Microsoft Academic Search

summary Confusion exists regarding what the core musculature is, how it is evalu- ated, how it is trained, and how it is applied to functional performance. The core musculature is divided into 2 systems, local (stabilization) and global (movement), with distinction between core-strength, core-stabili- ty, and functional exercises.

Mark D. Faries; Mike Greenwood

2007-01-01

343

The free core nutation  

NASA Astrophysics Data System (ADS)

The International Earth rotation and Reference system Service (IERS) provides observational determinations of the celestial pole offsets that describe quantitatively the difference between the observed direction of the Celestial Intermediate Pole in the celestial reference frame and the direction predicted by the conventional precession-nutation model. The free core nutation is the most significant component of that time series. This motion is due to the fact that the rotation axes of the core and mantle are not aligned, and it is seen in the observations as a periodic variation with a period of 432 days with time-variable amplitude and phase. The IERS is tasked with providing a numerical model for this motion. The current status of the free-core nutation models is reviewed and their accuracy is assessed.

McCarthy, D. D.

2005-09-01

344

Seismic response of a block-type nuclear reactor core. [HTGR  

Microsoft Academic Search

An analytical model is developed to predict seismic response of large gas-cooled reactor cores. The model is used to investigate scaling laws involved in the design of physical models of such cores, and to make parameter studies.

R. C. Dove; J. G. Bennett; J. L. Merson

1976-01-01

345

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.

346

Allied Health Core Curriculum: Its Time Has Come  

ERIC Educational Resources Information Center

|There is lack of a clear definition regarding an allied health core curriculum. The Pew Health Professions Commission and the Bureau of Health Professions use the following to define a core curriculum: "A set of interdisciplinary courses, clinical training, and other educational exposures designed to provide allied health students at each level…

McPherson, M. LaCheeta

2004-01-01

347

Mechanical behavior and constitutive modeling of metal cores  

Microsoft Academic Search

Studying the mechanical behavior of metal cores provides insight into the overall performance of struc- tures comprising metal sandwich plates, and can help immensely in designing metal sandwich plates for specific engineering applications. In this study, the response of folded (corrugated) plate and pyrami- dal truss cores are explored under both quasistatic and dynamic loadings. In particular, two important characteristics

Ashkan Vaziri; Zhenyu Xue

2007-01-01

348

Nuclear energy plant with collecting container for melting core masses  

Microsoft Academic Search

A nuclear energy plant with a reactor protecting container in which below the reactor core there is provided a cooled collecting container for molten core masses while cooling pipes are inserted in the wall of the collecting container. The cooling pipes are designed as heat pipes. One end of the pipes is arranged within the region of the inner wall

Katscher

1980-01-01

349

Seismic response of block-type nuclear reactor core. [HTGR  

Microsoft Academic Search

An analytical model is described that was developed to predict seismic response of large gas-cooled reactor cores. The model is used to investigate scaling laws involved in the design of physical models of such cores, and to make parameter studies.

J. G. Bennett; R. C. Dove; J. L. Merson

1977-01-01

350

Acoustics in mechanical engineering undergraduate core courses: Challenges and opportunities  

Microsoft Academic Search

Generally in an undergraduate curriculum of mechanical engineering, acoustics is not included as a core course. The major core courses deal with mechanics, design, dynamics of machinery, etc. However, engineering aspects of acoustics or noise can be included through elective courses. Given the limited slots for elective courses in a curriculum, it is difficult to run elective courses in acoustics

M. G. Prasad

2005-01-01

351

Essential Distinctiveness: Strategic Alternatives in Updating the Business Core Curriculum  

ERIC Educational Resources Information Center

|Purpose: This paper seeks to propose the use of specific strategic management tools for identifying opportunities for gaining competitive advantage in the business core curricula offered at colleges and universities. Design/methodology/approach: A brief review of the literature on business core curriculum innovation and change is examined, and…

Alstete, Jeffrey W.

2013-01-01

352

Evolution of First Cores and Formation of Stellar Cores in Rotating Molecular Cloud Cores  

Microsoft Academic Search

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 Omegac0. These evolutionary paths

Kazuya Saigo; Kohji Tomisaka; Tomoaki Matsumoto

2008-01-01

353

Getting to the Core  

Microsoft Academic Search

The Anne Arundel County Public Library developed a three phase reference project. During Phase I (12 months) a committee conducted a study of the reference holdings among the 13 branches and developed a core list of 250 reference titles for each branch. In Phase II (six months) the library explored ways to have staff learn to use these reference titles.

Ellen Berkov; Betty Morganstern

1990-01-01

354

Core-Noise.  

National Technical Information Service (NTIS)

This presentation is a technical progress report and near-term outlook for NASA-internal and NASA-sponsored external work on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of th...

L. S. Hultgren

2010-01-01

355

Renewing the Core Curriculum  

ERIC Educational Resources Information Center

|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…

Lawson, Hal A.

2007-01-01

356

The Earth's Core.  

ERIC Educational Resources Information Center

|The nature of the earth's core is described. Indirect evidence (such as that determined from seismological data) indicates that it is an iron alloy, solid toward its center but otherwise liquid. Evidence also suggests that it is the turbulent flow of the liquid that generates the earth's magnetic field. (JN)|

Jeanloz, Raymond

1983-01-01

357

Coring the Ocean Floor  

NSDL National Science Digital Library

This site explains how core samples are taken from the ocean floor. Topics include how research cruises are planned, who makes up the crew of a research vessel, and what a cruise track is. Links to additional information are embedded in the text.

358

Why a Core?  

ERIC Educational Resources Information Center

Sadly, amidst a vast profusion of knowledge, universities abrogate responsibility for showing young learners what is essential. Left to select for themselves, most students arrive late, if at all, to an awareness of what they want and need out of college. Thus, according to James Bernard Murphy, a well-constructed core of courses, presented in the…

Murphy, James Bernard

2006-01-01

359

Looking for Core Values  

ERIC Educational Resources Information Center

|People who view themselves as leaders, not just managers or teachers, are innovators who focus on clarifying core values and aligning all aspects of the organization with these values to grow their vision. A vision for an organization can't be just one person's idea. Visions grow by involving people in activities that help them name and create…

Carter, Margie

2010-01-01

360

Fairness and Core Knowledge.  

ERIC Educational Resources Information Center

The best way to help disadvantaged and minority children overcome educational injustice is to impart to them, and all students, a universally shared core of knowledge. Unless this is done, many disadvantaged and minority students will continue to lag behind their peers in academic achievement. Research has shown that systems that achieve…

Hirsch, E. D., Jr.

361

Learning Core Meanings.  

ERIC Educational Resources Information Center

An interactive vocabulary learning technique is described that uses a "core meaning" approach to help solve some of the problems learners have with English homonyms. The technique was used successfully with a class of adult learners but can be adapted for younger and less proficient learners. (four references) (LB)

Visser, Annette

1989-01-01

362

Utah's New Mathematics Core  

ERIC Educational Resources Information Center

|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…

Utah State Office of Education, 2011

2011-01-01

363

Core Directions in HRD.  

ERIC Educational Resources Information Center

|This document consists of four papers presented at a symposium on core directions in human resource development (HRD) moderated by Verna Willis at the 1996 conference of the Academy of Human Resource Development. "Reengineering the Organizational HRD Function: Two Case Studies" (Neal Chalofsky) reports an action research study in which the…

1996

364

Analysis of the Seismic Response of a Fast Reactor Core. Effects of the Vessel Core Seismic Interaction and Applications of the Results.  

National Technical Information Service (NTIS)

This report deals with the methods to apply for a correct evaluation of the reactor core seismic response. Reference is made to up-to-date design data concerning the PEC core, taking into account the presence of the core-restraint plate located close to t...

A. Martelli S. Chiocchio R. Melloni P. G. Muratori S. Rizzi

1984-01-01

365

Photon management with core-shell nanowire structures.  

PubMed

Antireflective Si/oxide core-shell nanowire arrays (NWAs) were fabricated by galvanic etching and subsequent annealing process. The excellent light-harvesting characteristics of the core-shell NWAs, such as broadband working ranges, omnidirectionality, and polarization-insensitivity, ascribed to the smooth index transition from air to the substrates, have been demonstrated. By tuning core-shell volume ratios, we obtained enhanced light trapping regions implemented in either the planar Si underneath NWAs or the core regions of NWAs, greatly benefiting the geometry design of planar and radial p-n junction cell structures, respectively. This photon management scheme indicates the potential use in nanostructured photovoltaic applications. PMID:22418674

Lai, Kun-Yu; Chang, Hung-Chih; Dai, Yu-An; He, Jr-Hau

2012-03-12

366

Lunar polar coring lander  

NASA Astrophysics Data System (ADS)

Plans to build a lunar base are presently being studied with a number of considerations. One of the most important considerations is qualifying the presence of water on the Moon. The existence of water on the Moon implies that future lunar settlements may be able to use this resource to produce things such as drinking water and rocket fuel. Due to the very high cost of transporting these materials to the Moon, in situ production could save billions of dollars in operating costs of the lunar base. Scientists have suggested that the polar regions of the Moon may contain some amounts of water ice in the regolith. Six possible mission scenarios are suggested which would allow lunar polar soil samples to be collected for analysis. The options presented are: remote sensing satellite, two unmanned robotic lunar coring missions (one is a sample return and one is a data return only), two combined manned and robotic polar coring missions, and one fully manned core retrieval mission. One of the combined manned and robotic missions has been singled out for detailed analysis. This mission proposes sending at least three unmanned robotic landers to the lunar pole to take core samples as deep as 15 meters. Upon successful completion of the coring operations, a manned mission would be sent to retrieve the samples and perform extensive experiments of the polar region. Man's first step in returning to the Moon is recommended to investigate the issue of lunar polar water. The potential benefits of lunar water more than warrant sending either astronauts, robots or both to the Moon before any permanent facility is constructed.

Angell, David; Bealmear, David; Benarroche, Patrice; Henry, Alan; Hudson, Raymond; Rivellini, Tommaso; Tolmachoff, Alex

1990-05-01

367

Pulse Transformer Design Study.  

National Technical Information Service (NTIS)

The design of a compact, lightweight, high average power, air-core pulse transformer to satisfy the electrical and physical requirements of a developmental power conditioning system is presented. (Author)

H. Aslin P. Chao

1975-01-01

368

17 CFR 38.800 - Core Principle 15.  

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

369

Solid0Core Heat-Pipe Nuclear Batterly Type Reactor  

SciTech Connect

This project was devoted to a preliminary assessment of the feasibility of designing an Encapsulated Nuclear Heat Source (ENHS) reactor to have a solid core from which heat is removed by liquid-metal heat pipes (HP).

Ehud Greenspan

2008-09-30

370

[The comparison of retention of diferent post and core systems].  

PubMed

To study the effects of different post design on retention. 27 simulated tooth roots made of PMMA were divided into three groups, then manufactured the cement-expanded composite screw post-core system (CECSP), cement screw post-core system (CSP) and cast metal post-core system (CMP). The root and post-core system was tensiled by the speed of 10 mm/min on the Instron 4302 and recorded the retention force. It appeared significantly different between retention force of CECSP and CSP and CAM (P < 0.05). As a result, the retention mechanical properties of CECSP was much better than those of cement screw post-core system and cast metal post-core system. Therefore, it is possible to find a new way for restoration of endodontically treated teeth. PMID:17333907

Wang, Nianbin; Chen, Xinmin; He, Tao; Yang, Yan; Zhang, Guiju; Wu, Xiaohong; Li, Pingping; Niu, Lin

2007-02-01

371

PRISMATIC CORE COUPLED TRANSIENT BENCHMARK  

SciTech Connect

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.

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

372

Overview on Hydrate Coring, Handling and Analysis  

SciTech Connect

Gas hydrates are crystalline, ice-like compounds of gas and water molecules that are formed under certain thermodynamic conditions. Hydrate deposits occur naturally within ocean sediments just below the sea floor at temperatures and pressures existing below about 500 meters water depth. Gas hydrate is also stable in conjunction with the permafrost in the Arctic. Most marine gas hydrate is formed of microbially generated gas. It binds huge amounts of methane into the sediments. Worldwide, gas hydrate is estimated to hold about 1016 kg of organic carbon in the form of methane (Kvenvolden et al., 1993). Gas hydrate is one of the fossil fuel resources that is yet untapped, but may play a major role in meeting the energy challenge of this century. In June 2002, Westport Technology Center was requested by the Department of Energy (DOE) to prepare a ''Best Practices Manual on Gas Hydrate Coring, Handling and Analysis'' under Award No. DE-FC26-02NT41327. The scope of the task was specifically targeted for coring sediments with hydrates in Alaska, the Gulf of Mexico (GOM) and from the present Ocean Drilling Program (ODP) drillship. The specific subjects under this scope were defined in 3 stages as follows: Stage 1: Collect information on coring sediments with hydrates, core handling, core preservation, sample transportation, analysis of the core, and long term preservation. Stage 2: Provide copies of the first draft to a list of experts and stakeholders designated by DOE. Stage 3: Produce a second draft of the manual with benefit of input from external review for delivery. The manual provides an overview of existing information available in the published literature and reports on coring, analysis, preservation and transport of gas hydrates for laboratory analysis as of June 2003. The manual was delivered as draft version 3 to the DOE Project Manager for distribution in July 2003. This Final Report is provided for records purposes.

Jon Burger; Deepak Gupta; Patrick Jacobs; John Shillinglaw

2003-06-30

373

Experimental Evaluation of Integrity of FBR Core under Seismic Events  

NASA Astrophysics Data System (ADS)

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.

Chellapandi, Perumal; Rajan Babu, Vinayagamoorthy; Puthiyavinayagam, Pillai; Chetal, Subhash Chander; Raj, Baldev

374

USGS CoreCast  

NSDL National Science Digital Library

Just about everyone seems to be creating a podcast these days, and a number of government agencies have entered the fray as of late. The United States Geological Survey recently decided to hang out their own podcast shingle, and the results of their labors can be explored here. The site states that their "CoreCast" is "natural science from the inside out", which seems like an appropriate label. The podcasts range in length from two to fifteen minutes, and they cover topics such as polar bear research, sex-changing fish, and climate change. One podcast that shouldn't be overlooked is "This Episode of CoreCast is Highly Questionable". In a mere three minutes, host Scott Horvath responds to a number of questions in an engaging fashion. After listening to an episode or two, visitors will probably want to sign up to receive email updates about new episodes.

375

The Core C API  

Microsoft Academic Search

\\u000a The core C API contains everything you need to process SQL commands and then some. It contains a variety of convenient query\\u000a methods that are useful in different ways. These include sqlite3_exec() and sqlite3_get_table(), which allow you to execute\\u000a commands in a single function call. The API includes many utility functions as well, allowing you to determine the number\\u000a of

Grant Allen; Mike Owens

376

Variable depth core sampler  

DOEpatents

A variable depth core sampler apparatus comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member.

Bourgeois, Peter M. (Hamburg, NY); Reger, Robert J. (Grand Island, NY)

1996-01-01

377

Banded electromagnetic stator core  

DOEpatents

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.

Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

1994-04-05

378

Banded electromagnetic stator core  

DOEpatents

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 figs.

Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

1996-06-11

379

Optimization of nanoparticle core size for magnetic particle imaging  

SciTech Connect

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.

Ferguson, Matthew R.; Minard, Kevin R.; Krishnan, Kannan M.

2009-05-01

380

Core-collapse Supernovae  

SciTech Connect

Marking the inevitable death of a massive star, and the birth of a neutron star or black hole, core-collapse supernovae bring together physics at a wide range in spatial scales, from kilometer-sized hydrodynamic motions (growing to gigameter scale) down to femtometer scale nuclear reactions. Carrying 10$^{51}$ ergs of kinetic energy and a rich-mix of newly synthesized atomic nuclei, core-collapse supernovae are the preeminent foundries of the nuclear species which make up ourselves and our solar system. We will discuss our emerging understanding of the convectively unstable, neutrino-driven explosion mechanism, based on increasingly realistic neutrino-radiation hydrodynamic simulations that include progressively better nuclear and particle physics. Recent multi-dimensional models with spectral neutrino transport from several research groups, which slowly develop successful explosions for a range of progenitors, have motivated changes in our understanding of the neutrino reheating mechanism. In a similar fashion, improvements in nuclear physics, most notably explorations of weak interactions on nuclei and the nuclear equation of state, continue to refine our understanding of how supernovae explode. Recent progress on both the macroscopic and microscopic effects that affect core-collapse supernovae are discussed.

Hix, William Raphael [ORNL; Lentz, E. J. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Baird, Mark L [ORNL; Chertkow, Merek A [ORNL; Lee, Ching-Tsai [University of Tennessee, Knoxville (UTK); Blondin, J. M. [North Carolina State University; Bruenn, S. W. [Florida Atlantic University, Boca Raton; Messer, Bronson [ORNL; Mezzacappa, Anthony [ORNL

2013-01-01

381

The truth about Earth's core?  

NSDL National Science Digital Library

This page uses the 1998 movie The Core (1998) to introduce what we actually know or suspect is true about the Earth's core. Includes discussion of current theories and mysteries from Rich Mueller (UC-Berkeley), with illustrations.

Preuss, Paul; Beat, Science

382

The Study of the Core Competitiveness's source and Formation Path of the Professional Sports Club in China  

Microsoft Academic Search

Starting with the conceptand connotation of core competitiveness and taking into consideration the status quo and model for Chinese professional sports clubs, this article scientifically analyzes the origin and formation of its core competitiveness to provide theoretical reference for designing the development strategy of the clubs and choosing the development direction of its core competitiveness. Keywords—professional sports, club, core competitiveness

Guangtao Zhao; Zheng Zhou

2011-01-01

383

Extending Amdahl's Law for Energy-Efficient Computing in the Many-Core Era  

Microsoft Academic Search

An updated take on Amdahl's analytical model uses modern design constraints to analyze many-core design alternatives. The revised models provide computer architects with a better understanding of many-core design types, enabling them to make more informed tradeoffs.

Dong Hyuk Woo; Hsien-hsin S. Lee

2008-01-01

384

Performance of Core Inflation Measures  

Microsoft Academic Search

This paper assesses the performance of core inflation measures based on the structural VAR approach. Since core or monetary inflation is not directly observable, we develop a monetary general equilibrium model that fits real aggregated European data and we use this model to generate time series for headline as well as core inflation. For five different schemes which attempt to

C. K. Folkertsma; K. Hubrich

2001-01-01

385

A new 122 mm electromechanical drill for deep ice-sheet coring (DISC): 4. Drill cable  

Microsoft Academic Search

The deep ice-sheet coring (DISC) drill developed by Ice Coring and Drilling Services (ICDS) under contract with the US National Science Foundation requires a drill cable capable of transmitting high amounts of electrical power as well as high rates of data. The DISC cable was designed and manufactured by the Rochester Corporation to core ice to depths of 4000 m.

Alexander J. Shturmakov; Paul J. Sendelbach

2007-01-01

386

Shear buckling in foam-filled web core sandwich panels using a Pasternak foundation model  

Microsoft Academic Search

Web core panels, foam-filled sandwich panels with interior webs, are a structurally efficient option for transverse load bearing applications. In web core panels, the interaction between the webs and core material can have a substantial impact on web shear buckling strength and is a key element of lightweight structural design. The present work is an investigation of web buckling behavior

Casey R. Briscoe; Susan C. Mantell; Jane H. Davidson

2010-01-01

387

Core Modification to Improve Irradiation Efficiency of the Experimental Fast Reactor Joyo  

Microsoft Academic Search

Core modification has been investigated to further increase the core burnup and to improve the irradiation efficiency of the experimental fast reactor Joyo. This modification enables the core to accommodate more irradiation test subassemblies that have lower fissile material contents compared with the driver fuel. The design calculations showed that the replacement of the radial reflector elements made of stainless

Shigetaka MAEDA; Masaya YAMAMOTO; Tomonori SOGA; Takashi SEKINE; Takafumi AOYAMA

2011-01-01

388

Development of a method for partially uninvaded coring in high-permeability sandstone  

SciTech Connect

A newly designed polycrystalline-diamond-compact (PDC) core bit muds with bridging solids are shown to provide 4-in. diameter cores with a 2.5-in. uninvaded center. High-permeability cored at rates exceeding 90 ft/hr in laboratory and field tests. The mechanisms controlling filtrate invasion are quantified.

Rathmell, J.J.; Warner, H.R. Jr. [Arco E and P Technology, Plano, TX (United States); Tibbitts, G.A. [Hughes-Christensen Co., Salt Lake City, UT (United States); Gremley, R.B.; White, E.K.

1995-06-01

389

Assessment of the Immunity of Unshielded Multi-Core Integrated Circuits to Near-Field Injection  

Microsoft Academic Search

This paper presents a comparative assessment of the electromagnetic immunity of 4 integrated logic cores to near-field injection. These cores, located on the same die, are identical from a functional point of view, but differ by their design strategies. The injection is performed above each core according to the 6 components of the electromagnetic field, using appropriate probes. These results

Ali Alaeldine; Thomas Ordas; Richard Perdriau; Philippe Maurine; Mohamed Ramdani; L. Torres; M. Drissi

2009-01-01

390

THE COLORADO PLATEAU CORING PROJECT: THE TIMESCALE AND TEMPO OF BIOTIC CHANGE OF THE EARLY MESOZOIC  

Microsoft Academic Search

The proposed Colorado Plateau Coring Project (CPCP) is an interdisciplinary, multi-institutional coring project designed to recover continuous core through mostly continental strata spanning ~100 million years of the Triassic and Jurassic. Its principal purpose is to tie the incredibly rich faunas, floras, and environmental record of this interval to a rigorously developed timescale and thus to biotic, environmental, and tectonic

P. E. Olsen; D. V. Kent; R. Mundil; R. Irmis; J. W. Geissman; J. Martz; W. Parker

2009-01-01

391

Numerical and Experimental Model Studies on Thermal Hydraulic Behavior of FBR Internal Core Catcher Assembly  

Microsoft Academic Search

Core Catcher is provided as an in-vessel core debris retention device to collect, support, cool and maintain in sub-critical configuration, the generated core debris from fuel melting due to certain postulated Beyond Design Basis Events (BDBE) for Fast Breeder Reactor (FBR). This also acts as a barrier to prevent settling of debris on main vessel and keeps its maximum temperature

Sanjay Kumar Das; Anil Kumar Sharma; A. Jasmin Sudha; G. Punitha; G. Lydia; P. A. Somayajulu; S. S. Murthy; B. Malarvizhi; V. Gopalakrishnan; J. Harvey; N. Kasinathan; M. Rajan

2006-01-01

392

Analyzing core-periphery structure of complex product development using social network analysis  

Microsoft Academic Search

This paper explores the core-periphery structure of complex product development process from the perspectives of information flow and social network. We use the design structure matrix to display product development process, and employ the social network analysis to identify and explain the core-periphery structure in complex product development process. We discuss how to detect the core and periphery processes in

Hongbo Li; Zhe Xu

2011-01-01

393

Implications of Merging Phases on Scalability of Multi-core Architectures  

Microsoft Academic Search

Amdahl's Law dictates that in parallel applica- tions serial sections establish an upper limit on the scalability. Asymmetric chip multiprocessors with a large core in addition to several small cores have been advocated for recently as a promising design paradigm because the large core can accelerate the execution of serial sections and hence mitigate the scalability bottlenecks due to large

Madhavan Manivannan; Ben Juurlink; Per Stenstrom

2011-01-01

394

Demonstration program for a mini in-core instrument assembly  

SciTech Connect

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.

Kantrowitz, M.L.; Terney, W.B. (ABB Combustion Engineering Nuclear Power, Inc., Windsor, CT (United States))

1992-01-01

395

PROCESS FOR JACKETING A CORE  

DOEpatents

A process is given for enclosing the uranium core of a nuclear fuel element by placing the core in an aluminum cup and closing the open end of the cup over the core. As the metal of the cup is brought together in a weld over the center of the end of the core, it is extruded inwardly as internal projection into a central recess in the core and outwardly as an external projection. Thus oxide inclusions in the weld of the cup are spread out into the internal and external projections and do not interfere with the integrity of the weld.

Last, G.A.

1960-07-19

396

Optimization of cylindrical shells with compliant cores  

Microsoft Academic Search

Thin-walled, cylindrical structures are found extensively in both engineering components and in nature. The weight to load bearing ratio is a critical element of design of such structures in a variety of engineering applications, including space shuttle fuel tanks, aircraft fuselages, and offshore oil platforms. In nature, thin-walled cylindrical structures are often supported by a honeycomb- or foam-like cellular core,

Matthew A. Dawson; Lorna J. Gibson

2007-01-01

397

Saturated Cores FCL—A New Approach  

Microsoft Academic Search

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,

V. Rozenshtein; A. Friedman; Y. Wolfus; F. Kopansky; E. Perel; Y. Yeshurun; Z. Bar-Haim; Z. Ron; E. Harel; N. Pundak

2007-01-01

398

Integrally cored ceramic investment casting mold fabricated by ceramic stereolithography  

NASA Astrophysics Data System (ADS)

Superalloy airfoils are produced by investment casting (IC), which uses ceramic cores and wax patterns with ceramic shell molds. Hollow cored superalloy airfoils in a gas turbine engine are an example of complex IC parts. The complex internal hollow cavities of the airfoil are designed to conduct cooling air through one or more passageways. These complex internal passageways have been fabricated by a lost wax process requiring several processing steps; core preparation, injection molding for wax pattern, and dipping process for ceramic shell molds. Several steps generate problems such as high cost and decreased accuracy of the ceramic mold. For example, costly tooling and production delay are required to produce mold dies for complex cores and wax patterns used in injection molding, resulting in a big obstacle for prototypes and smaller production runs. Rather than using separate cores, patterns, and shell molds, it would be advantageous to directly produce a mold that has the casting cavity and the ceramic core by one process. Ceramic stereolithography (CerSLA) can be used to directly fabricate the integrally cored ceramic casting mold (ICCM). CerSLA builds ceramic green objects from CAD files from many thin liquid layers of powder in monomer, which are solidified by polymerization with a UV laser, thereby "writing" the design for each slice. This dissertation addresses the integrally cored casting ceramic mold (ICCM), the ceramic core with a ceramic mold shell in a single patternless construction, fabricated by ceramic stereolithography (CerSLA). CerSLA is considered as an alternative method to replace lost wax processes, for small production runs or designs too complex for conventional cores and patterns. The main topic is the development of methods to successfully fabricate an ICCM by CerSLA from refractory silica, as well as related issues. The related issues are the segregation of coarse fused silica powders in a layer, the degree of segregation parameter to prevent segregation, and sintering and cristobalite transformation in fused silica compacts.

Bae, Chang-Jun

399

Safety design of prototype fast breeder reactor  

SciTech Connect

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)

Bhoje, S.B.; Chetal, S.C.; Singh, Om Pal [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

2004-07-01

400

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.

401

CANOPEN Controller IP Core  

NASA Astrophysics Data System (ADS)

This paper will describe the activities performed by Thales Alenia Space Italia supported by the European Space Agency in the definition of a CAN bus interface to be used on Exomars. The final goal of this activity is the development of an IP core, to be used in a slave node, able to manage both the CAN bus Data Link and Application Layer totally in hardware. The activity has been focused on the needs of the EXOMARS mission where devices with different computational performances are all managed by the onboard computer through the CAN bus.

Caramia, M.; Montagna, M.; Furano, G.; Winton, A.

2010-08-01

402

A Technique to Determine Billet Core Charge Weight for P/M Fuel Tubes  

SciTech Connect

The core length in an extruded tube depends on the weight of powder in the billet core. In the past, the amount of aluminum powder needed to give a specified core length was determined empirically. This report gives a technique for calculating the weight of aluminum powder for the P/M core. An equation has been derived which can be used to determine the amount of aluminum needed for P/M billet core charge weights. Good agreement was obtained when compared to Mark 22 tube extrusion data. From the calculated charge weight, the elastomeric bag can be designed and made to compact the U3O8-Al core.

Peacock, H.B.

2001-07-02

403

A New Paradigm for Ice Core Drilling  

NASA Astrophysics Data System (ADS)

The search for answers to questions about the changing climate has created an urgent need to discover past climate signatures archived in glaciers and ice sheets, and to understand current ice sheet behavior. Recognizing that U.S. scientific productivity in this area depends upon a mechanism for ensuring continuity and international cooperation in ice coring and drilling efforts, along with the availability of appropriate drills, drilling expertise, and innovations in drilling technology, the U.S. National Science Foundation (NSF) has established the Ice Drilling Program Office (IDPO) and its partner, the Ice Drilling Design and Operations group (IDDO), together known as IDPO/IDDO (Figure 1). This approach to integrated research and technology planning and delivery replaces the prior approach to drilling, which involved a series of NSF contracts with the Polar Ice Coring Office (PICO) and Ice Coring and Drilling Services (ICDS). This contracting approach lacked integrated planning. Previously, NSF had no way to forecast what science the community would propose—it would get compelling climate proposals that needed ice cores for data, but in many cases no existing drill could retrieve the core needed in the proposal. Constructing the needed drill—a process that takes years—forced science objectives to be put on hold. Now the science community is able to give feedback on its needs to IDPO/IDDO continually, allowing those who develop drilling technology to begin designing and constructing drills that scientists will need for the science proposals that they will submit years in the future. As such, IDPO/IDDO represents a new paradigm for integrated science and science support.

Albert, Mary; Bentley, Charles; Twickler, Mark

2010-09-01

404

A New Design Approach for Axial-Field Electrical Machines  

Microsoft Academic Search

The laminated core of an axial-field electrical machine is usually made of a strip-wound circular core which is machined to form the slots. This paper presents a new design and method of construction for the laminated cores of axial-field electrical machines. The laminated core, viz. armature or stator core, is sandwiched between two field cores. As there is no yoke

Wai Leung; James C. Chan

1980-01-01

405

Watermarking strategies for IP protection of micro-processor cores  

NASA Astrophysics Data System (ADS)

Reuse-based design has emerged as one of the most important methodologies for integrated circuit design, with reusable Intellectual Property (IP) cores enabling the optimization of company resources due to reduced development time and costs. This is of special interest in the Field-Programmable Logic (FPL) domain, which mainly relies on automatic synthesis tools. However, this design methodology has brought to light the intellectual property protection (IPP) of those modules, with most forms of protection in the EDA industry being difficult to translate to this domain. However, IP core watermarking has emerged as a tool for IP core protection. Although watermarks may be inserted at different levels of the design flow, watermarking Hardware Description Language (HDL) descriptions has been proved to be a robust and secure option. In this paper, a new framework for the protection of ?P cores is presented. The protection scheme is derived from the IPP@HDL procedure and it has been adapted to the singularities of ?P cores, overcoming the problems for the digital signature extraction in such systems. Additionally, the feature of hardware activation has been introduced, allowing the distribution of ?P cores in a "demo" mode and a later activation that can be easily performed by the customer executing a simple program. Application examples show that the additional hardware introduced for protection and/or activation has no effect over the performance, and showing an assumable area increase.

Parrilla, L.; Castillo, E.; Meyer-Bäse, U.; García, A.; González, D.; Todorovich, E.; Boemo, E.; Lloris, A.

2010-04-01

406

Nanocomposite plasmonic fluorescence emitters with core/shell configurations.  

SciTech Connect

This paper is focused on the optical properties of nanocomposite plasmonic emitters with core/shell configurations, where a fluorescence emitter is located inside a metal nanoshell. Systematic theoretical investigations are presented for the influence of material type, core radius, shell thickness, and excitation wavelength on the internal optical intensity, radiative quantum yield, and fluorescence enhancement of the nanocomposite emitter. It is our conclusion that: (i) an optimal ratio between the core radius and shell thickness is required to maximize the absorption rate of fluorescence emitters, and (ii) a large core radius is desired to minimize the non-radiative damping and avoid significant quantum yield degradation of light emitters. Several experimental approaches to synthesize these nanocomposite emitters are also discussed. Furthermore, our theoretical results are successfully used to explain several reported experimental observations and should prove useful for designing ultra-bright core/shell nanocomposite emitters.

Brener, Igal; Luk, Ting Shan; Miao, Xiaoyu

2010-06-01

407

Power excursion analysis for high burnup cores  

SciTech Connect

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.

Diamond, D.J.; Neymotin, L.; Kohut, P. [Brookhaven National Lab., Upton, NY (United States)

1996-02-01

408

New Drilling Core Facility  

NASA Astrophysics Data System (ADS)

A new Department of Energy (DOE) facility, dedicated to curating samples, cores, and other materials obtained under the Continental Scientific Drilling Program (CSDP), will become available early in 1985 in Grand Junction, Colo. The facility will be operated by DOE in cooperation with the U.S. Geological Survey and the National Science Foundation. The three agencies are working together on continental scientific drilling in the United States under their formally adopted Interagency Accord on Scientific Drilling.From the time they are gathered at the drill site, these samples and routine logging data will be protected under Curatorial Policy Guidelines and Procedures. These guidelines and procedures are intended to provide maximum sample study opportunity, to preserve samples for future study, and to ensure longrange continuing service to the principle investigator and to the geoscience community.

409

NEUTRONIC REACTOR CORE INSTRUMENT  

DOEpatents

A multi-purpose instrument for measuring neutron flux, coolant flow rate, and coolant temperature in a nuclear reactor is described. The device consists essentially of a hollow thimble containing a heat conducting element protruding from the inner wall, the element containing on its innermost end an amount of fissionsble materinl to function as a heat source when subjected to neutron flux irradiation. Thermocouple type temperature sensing means are placed on the heat conducting element adjacent the fissionable material and at a point spaced therefrom, and at a point on the thimble which is in contact with the coolant fluid. The temperature differentials measured between the thermocouples are determinative of the neutron flux, coolant flow, and temperature being measured. The device may be utilized as a probe or may be incorporated in a reactor core. (AE C)

Mims, L.S.

1961-08-22

410

Out-of-Core Computation of the QR Factorization on Multi-core Processors  

NASA Astrophysics Data System (ADS)

We target the development of high-performance algorithms for dense matrix operations where data resides on disk and has to be explicitly moved in and out of the main memory. We provide strong evidence that, even for a complex operation like the QR factorization, the use of a run-time system creates a separation of concerns between the matrix computations and I/O operations with the result that no significant changes need to be introduced to existing in-core algorithms. The library developer can thus focus on the design of algorithms-by-blocks, addressing disk memory as just another level of the memory hierarchy. Experimental results for the out-of-core computation of the QR factorization on a multi-core processor reveal the potential of this approach.

Marqués, Mercedes; Quintana-Ortí, Gregorio; Quintana-Ortí, Enrique S.; van de Geijn, Robert

411

Growth outside the core.  

PubMed

Growth in an adjacent market is tougher than it looks; three-quarters of the time, the effort fails. But companies can change those odds dramatically. Results from a five-year study of corporate growth conducted by Bain & Company reveal that adjacency expansion succeeds only when built around strong core businesses that have the potential to become market leaders. And the best place to look for adjacency opportunities is inside a company's strongest customers. The study also found that the most successful companies were able to consistently, profitably outgrow their rivals by developing a formula for pushing out the boundaries of their core businesses in predictable, repeatable ways. Companies use their repeatability formulas to expand into any number of adjacencies. Some companies make repeated geographic moves, as Vodafone has done in expanding from one geographic market to another over the past 13 years, building revenues from $1 billion in 1990 to $48 billion in 2003. Others apply a superior business model to new segments. Dell, for example, has repeatedly adapted its direct-to-customer model to new customer segments and new product categories. In other cases, companies develop hybrid approaches. Nike executed a series of different types of adjacency moves: it expanded into adjacent customer segments, introduced new products, developed new distribution channels, and then moved into adjacent geographic markets. The successful repeaters in the study had two common characteristics. First, they were extraordinarily disciplined, applying rigorous screens before they made an adjacency move. This discipline paid off in the form of learning curve benefits, increased speed, and lower complexity. And second, in almost all cases, they developed their repeatable formulas by studying their customers and their customers' economics very, very carefully. PMID:14712545

Zook, Chris; Allen, James

2003-12-01

412

Mononuclear manganese(III) complexes as building blocks for the design of trinuclear manganese clusters: study of the ligand influence on the magnetic properties of the [Mn3(mu3-O)](7+) core.  

PubMed

The synthesis, crystal structure, and magnetic properties of three new manganese(III) clusters are reported, [Mn 3(mu 3-O)(phpzH) 3(MeOH) 3(OAc)] (1), [Mn 3(mu 3-O)(phpzMe) 3(MeOH) 3(OAc)].1.5MeOH (2), and [Mn 3(mu 3-O)(phpzH) 3(MeOH) 4(N 3)].MeOH (3) (H 2phpzH = 3(5)-(2-hydroxyphenyl)-pyrazole and H 2phpzMe = 3(5)-(2-hydroxyphenyl)-5(3)-methylpyrazole). Complexes 1- 3 consist of a triangle of manganese(III) ions with an oxido-center bridge and three ligands, phpzR (2-) (R = H, Me) that form a plane with the metal ions. All the complexes contain the same core with the general formula [Mn 3(mu 3-O)(phpzR) 3] (+). Methanol molecules and additional bridging ligands, that is, acetate (complexes 1 and 2) and azide (complex 3), are at the terminal positions. Temperature dependent magnetic susceptibility studies indicate the presence of predominant antiferromagnetic intramolecular interactions between manganese(III) ions in 1 and 3, while both antiferromagnetic and ferromagnetic intramolecular interactions are operative in 2. PMID:18543906

Viciano-Chumillas, Marta; Tanase, Stefania; Mutikainen, Ilpo; Turpeinen, Urho; de Jongh, L Jos; Reedijk, Jan

2008-06-11

413

A vectorized heat transfer model for solid reactor cores  

Microsoft Academic Search

The new generation of nuclear reactors includes designs that are significantly different from light water reactors. Among these new reactor designs is the Modular High-Temperature Gas-Cooled Reactor (MHTGR). In addition, nuclear thermal rockets share a number of similarities with terrestrial HTGRs and would be amenable to similar types of analyses. In these reactors, the heat transfer in the solid core

W. J. Rider; M. W. Cappiello; D. R. Liles

1990-01-01

414

A vectorized heat transfer model for solid reactor cores  

Microsoft Academic Search

The new generation of nuclear reactors includes designs that are significantly different from light water reactors. Among these new reactor designs is the modular high-temperature gas-cooled reactor (HTGR). In addition, nuclear thermal rockets share a number of similarities with terrestrial HTGRs and would be amendable to similar types of analyses. In these reactors, the heat transfer in the solid core

W. J. Rider; M. W. Cappiello; D. R. Liles

1990-01-01

415

Experimental results and analysis of core physics experiments, FUBILA, for high burn-up BWR full MOX cores  

SciTech Connect

JNES has been performing MOX core physics experiments, FUBILA, in the EOLE critical facility of the CEA Cadarache center with collaboration of a French Consortium (CEA and COGEMA). The experiments have been designed to obtain the core physics data of operating conditions of full MOX BWR cores consisting of high burn up BWR MOX assemblies. The experiments consisting of seven different core configurations started from January 2005 and will be completed by August 2006. Theoretical analysis of the experimental data has been also carried out using a deterministic code, SRAC, and a continuous energy Monte Carlo calculation code, MVP, with major nuclear data libraries, JENDL-3.3, 3.2, ENDF/B-VI and JEFF-3.1 for the first critical core. (authors)

Yamamoto, T.; Kikuchi, S.; Kawashima, K.; Kamimura, K. [Japan Nuclear Energy Safety Organization, 3-17-1, Toranomon, Minato-ku, Tokyo 105-0001 (Japan)

2006-07-01

416

Nanocrystalline soft magnetic composite cores  

Microsoft Academic Search

The microstructure and soft magnetic properties, i.e. saturation induction, remanence, coercivity and permeability of high-energy ball milled nanostructured FINEMET powder cores and nanocomposite cores with average powder particles diameter between 25 and 75?m, 300 and 500?m and 750 and 1200?m are presented in this paper. These results showed that the permeability of the powder and composite cores increases if the

R. Nowosielski; J. J. Wys?ocki; I. Wnuk; P. Gramatyka

2006-01-01

417

A method for reducing encapsulation stress to ferrite pot cores  

SciTech Connect

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.

Sanchez, R.O.

1994-08-01

418

Core-shell noble metal nanostructures templated by gold nanorods.  

PubMed

The main research progress in core-shell noble metal nanostructures templated by gold nanorods (Au NRs) is summarized regarding synthesis, optical, and catalytic properties. Design and fabrication of core-shell hybrid nanostructures are demonstrated to be effective not only for optimizing and expanding intrinsic properties but also for creating novel localized surface plasmon enhanced optical and catalytic functionalities, thus providing great prospects in both fundamental research and potential applications. PMID:24048971

Hou, Shuai; Hu, Xiaona; Wen, Tao; Liu, Wenqi; Wu, Xiaochun

2013-05-24

419

Accident analyses for a double-flat-core-type HCLWR  

Microsoft Academic Search

A double-flat-core-type high conversion light water reactor (HCLWR) has been developed at Japan Atomic Energy Research Institute (JAERI) to improve fuel utilization, preserving the same safety margin as for the current light water reactors (LWRs). In the present design, two pancake-type flat cores are piled up with lower, internal, and upper blankets to keep the void reactivity coefficient negative. The

Tsutomu Okubo; Takamachi Iwamura; Takayuki Suemura; Fujio Hiraga; Yoshio Murao

1990-01-01

420

Rotational Magnetization in Transformer Cores—A Review  

Microsoft Academic Search

Usually, rotational magnetization (RM) is associated with rotating machine cores. However, in more restricted ways, it also arises in three-phase transformer cores. Modern designs of T-joint yield detours of flux, as a source of RM in the T-joint, the middle limb ends, as well as in the yokes. Simulation of RM is possible by means of so-called rotational single sheet

Helmut Pfutzner; Edin Mulasalihovic; Hiroi Yamaguchi; Damir Sabic; Georgi Shilyashki; Franz Hofbauer

2011-01-01

421

Multi-core advantages for mask data preparation  

NASA Astrophysics Data System (ADS)

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.

Yeap, Johnny; Nogatch, John

2009-04-01

422

Ex-core to in-core flux map calibration  

SciTech Connect

This paper presents a method for calibrating ex-core detectors to in-core flux maps for Westinghouse pressurized water reactors. The method is described and results are given for a reactor unit that is typical of a number of units analyzed.

Lacy, P.S.; Rapp, J.S. (Utility Resource Associates, Rockville, MD (USA)); Kapitz, J. (Northern States Power Company, Welch, MN (USA))

1989-11-01

423

Ice Core Dating Software for Interactive Dating of Ice Cores  

Microsoft Academic Search

Scientists involved in ice core dating are well familiar with the problem of identification and recording the depth of annual signals using stable isotopes, glaciochemistry, ECM (electrical conductivity), DEP (dielectric properties) and particle counter data. Traditionally all parameters used for ice core dating were plotted as a function of depth, printed and after years were marked on the paper, converted

A. V. Kurbatov; P. A. Mayewski; B. S. Abdul Jawad

2005-01-01

424

Data Acquisition Backbone Core DABC  

NASA Astrophysics Data System (ADS)

For the new experiments at FAIR new concepts of data acquisition systems have to be developed like the distribution of self-triggered, time stamped data streams over high performance networks for event building. The Data Acquisition Backbone Core (DABC) is a software package currently under development for FAIR detector tests, readout components test, and data flow investigations. All kinds of data channels (front-end systems) are connected by program plug-ins into functional components of DABC like data input, combiner, scheduler, event builder, analysis and storage components. After detailed simulations real tests of event building over a switched network (InfiniBand clusters with up to 110 nodes) have been performed. With the DABC software more than 900 MByte/s input and output per node can be achieved meeting the most demanding requirements. The software is ready for the implementation of various test beds needed for the final design of data acquisition systems at FAIR. The development of key components is supported by the FutureDAQ project of the European Union (FP6 I3HP JRA1).

Adamczewski, J.; Essel, H. G.; Kurz, N.; Linev, S.

2008-07-01

425

Bifunctional optimization of actively cooled, pressurized hollow sandwich cylinders with prismatic cores  

Microsoft Academic Search

All metallic, hollow sandwich cylinders having ultralight two-dimensional (2D) prismatic cores are optimally designed for maximum thermo-mechanical performance at minimum mass. The heated cylinder is subjected to uniform internal pressure and actively cooled by forced air convection. The use of two different core topologies is exploited: square- and triangular-celled cores. The minimum mass design model is so defined that three

T. Liu; Z. C. Deng; T. J. Lu

2007-01-01

426

Thread shuffling: Combining DVFS and thread migration to reduce energy consumptions for multi-core systems  

Microsoft Academic Search

In recent years, multi-core systems have become mainstream in computer industry. The design of multi-cores takes advantage of thread-level parallelism in emerging applications that are computationally intensive and highly parallel. Energy efficiency is one of the biggest challenges in the design of multi-core systems, and workload imbalance among parallel threads is one of sources of energy inefficiency. Many techniques based

Qiong Cai; Jose Gonzalez; Grigorios Magklis; Pedro Chaparro; Antonio Gonzalez

2011-01-01

427

Core foundations of abstract geometry  

PubMed Central

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.

Dillon, Moira R.; Huang, Yi; Spelke, Elizabeth S.

2013-01-01

428

Progress in crystalline semiconductor core optical fibers  

NASA Astrophysics Data System (ADS)

Recently developed glass-clad crystalline semiconductor core optical fibers potentially offer a series of advantages over present optical fiber materials including greatly enhanced Raman cross-sections and extended infrared transparency. Indeed, the low-cost high-through-put fiberization of crystalline materials could permit a step-jump in performance critical for use in high energy laser, infrared counter-measure, communication, and sensor systems. Further, the high degree of crystallinity is of considerable scientific value since optical fiber fabrication is a highly non-equilibrium process and so achieving high degrees of crystallinity is very counter-intuitive and offers new insight into crystal growth mechanisms. This talk will review progress in glass-clad fibers possessing cores of highly crystalline silicon and germanium including anomalies in Si and Ge that may benefit fiber fabrication as well as paths forward to optimization of fiber design and performance.

Ballato, J.; Hawkins, T.; Foy, P.; McMillen, C.; Stolen, R.; Rice, R.

2010-02-01

429

Core Competencies for Injury and Violence Prevention  

PubMed Central

Efforts to reduce the burden of injury and violence require a workforce that is knowledgeable and skilled in prevention. However, there has been no systematic process to ensure that professionals possess the necessary competencies. To address this deficiency, we developed a set of core competencies for public health practitioners in injury and violence prevention programs. The core competencies address domains including public health significance, data, the design and implementation of prevention activities, evaluation, program management, communication, stimulating change, and continuing education. Specific learning objectives establish goals for training in each domain. The competencies assist in efforts to reduce the burden of injury and violence and can provide benchmarks against which to assess progress in professional capacity for injury and violence prevention.

Stephens-Stidham, Shelli; Peek-Asa, Corinne; Bou-Saada, Ingrid; Hunter, Wanda; Lindemer, Kristen; Runyan, Carol

2009-01-01

430

MOX fuel arrangement for nuclear core  

DOEpatents

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.

Kantrowitz, M.L.; Rosenstein, R.G.

1998-10-13

431

Status of ASME Section III Task Group on Graphite Support Core Structures  

SciTech Connect

This report outlines the roadmap that the ASME Project Team on Graphite Core Supports is pursuing to establish design codes for unirradiated and irradiated graphite core components during its first year of operation. It discusses the deficiencies in the proposed Section III, Division 2, Subsection CE graphite design code and the different approaches the Project Team has taken to address those deficiencies.

Robert L. Bratton; Tim D. Burchell

2005-08-01

432

FACE core environment: the model and its application in CAE\\/CAD tool development  

Microsoft Academic Search

Many aspects of design automation software have similar requirements for representing, manipulating, and storing design information. The recognition of these common requirements in CAD tools, allows the Flexible Architecture Compilation Environment's (FACE) Core Environment to provide a suite of high level tools for the CAD developer. The Core Environment software has been developed using object-oriented software technology, and may be

William D. Smith; David A. Duff; M. Dragomirecky; J. Caldwell; Michael J. Hartman; Jeffrey R. Jasica; Manuel A. d'Abreu

1989-01-01

433

The CORE paradigm: a 21st century approach to pastoral ministry  

Microsoft Academic Search

Through the CORE Paradigm, I will present a training program designed to empower pastoral students at Valley Forge Christian College to be healthy in pastoral ministry. The concepts in The CORE Paradigm Training Program are designed to address four critical areas of the student's life: (a) Christ-centeredness (C) (b) ownership of responsibility (O) (c) relational connectedness (R) (d) and enjoying

David Scolforo

2004-01-01

434

High-temperature superconducting magnet for use in saturated core FCL  

Microsoft Academic Search

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

Z Bar-Haim; A Friedman; Y Wolfus; V Rozenshtein; F Kopansky; Z Ron; E Harel; N Pundak; Y Yeshurun

2008-01-01

435

Reinforced Foam Core Acoustic Baffle.  

National Technical Information Service (NTIS)

A reinforced foam core acoustic baffle includes a pressure-release polystyrene foam core, upper and lower steel reinforcing plates, a plurality of steel reinforcing rods, and a high-density foam skirt. The reinforcing plates are bonded to the upper and lo...

J. J. Hagerty

1993-01-01

436

Core collapse with strong encounters  

Microsoft Academic Search

This paper explores the possibility that close two-body encounters, though normally unimportant for the evolution of systems of point masses, may be important in the late stages of core collaspe when fewer than 100 particles remain in the core. An orbit-averaged integral equation in energy space is given for the time development of the system, on the assumption that all

J. Goodman

1983-01-01

437

Teachers' Domain Common Core Collection  

NSDL National Science Digital Library

This collection provides a selection of 300 resources from Teachers' Domain, selected because they support the represent approaches to using digital media to support the Common Core State Standards for English Language Arts & Literacy in Science and Technical Subjects, the Common Core State Standards for Mathematics, or the approaches to science education detailed in the Framework for K-12 Science Education.

2012-08-28

438

Experimental Constraints on Core Composition  

Microsoft Academic Search

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;

J. Li; Y. Fei

2003-01-01

439

Mathematics Common Core Unpacked: Kindergarten  

NSDL National Science Digital Library

This document provides descriptions and examples of what each Mathematics Common Core standard means a Kindergarten student will know, understand and be able to do. This "unpacking" of the standards provides instructional guidelines and was developed to assist North Carolina educators teach the Mathematics Common Core (Standard Course of Study).

Uncc, Ew P.

2012-08-01

440

Core Knowledge: One Teacher's Experience.  

ERIC Educational Resources Information Center

One fifth-grade teacher feels it is unfair if some students learn one thing, while others learn something else. Teachers must agree on some core of specific content and resolve to teach it at appropriate levels. Core Knowledge Sequence for grades 1-6 provides model of grade-by-grade content including literature, U.S. and world civilization,…

Storm, Jeanne

1993-01-01

441

Variable depth core sampler  

DOEpatents

This invention relates to a sampling means, more particularly to a device to sample hard surfaces at varying depths. Often it is desirable to take samples of a hard surface wherein the samples are of the same diameter but of varying depths. Current practice requires that a full top-to-bottom sample of the material be taken, using a hole saw, and boring a hole from one end of the material to the other. The sample thus taken is removed from the hole saw and the middle of said sample is then subjected to further investigation. This paper describes a variable depth core sampler comprimising a circular hole saw member, having longitudinal sections that collapse to form a point and capture a sample, and a second saw member residing inside the first hole saw member to support the longitudinal sections of the first member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside the the first hole saw member.

Bourgeois, P.M.; Reger, R.J.

1994-12-31

442

The EPOS Integrated Core Services  

NASA Astrophysics Data System (ADS)

The European Plate Observing System (EPOS) is integrating the diverse, but advanced Research Infrastructures in Europe for solid Earth Science, and will build on new e-science opportunities to monitor and understand the dynamic and complex solid-Earth System. This integration requires a significant coordination between, among others, disciplinary (thematic) communities, national RIs policies and initiatives, and geo- and IT-scientists. The RIs that EPOS will coordinate include at least, but not only: regionally-distributed geophysical observing systems (seismological and geodetic networks), local observatories (including geomagnetic, permanent in-situ and volcano observatories), experimental & analogue laboratories in Europe, integrated satellite data and geological information. EPOS is promoting open access to geophysical and geological data as well as modelling/processing tools, enabling a step change in multidisciplinary scientific research for Earth Sciences The EPOS e-infrastructure is developed through strawman (initial design / architecture), woodman (refined design/architecture) and ironman (final design/architecture) phases. Midway in the project we are in the woodman phase based on extensive primary requirements from users and secondary requirements for interoperation with other geoscience systems, other European environmental research infrastructure projects and e-infrastructure projects (e.g. EUDAT). The EPOS e-infrastructure is being developed along 3 parallel tracks: (a) an inventory of assets offered by organisations within the EPOS community. The RIDE (Research Infrastructure Database for EPOS) system from the strawman phase is being extended in the woodman phase to the metadata catalog describing computing and scientific resources, data, services (software), and users which will drive the EPOS e-infrastructure; (b) refining an architecture to meet the requirements. This is an iterative process with the working groups (organised thematically) within EPOS also including other work packages in EPOS such as those concerned with legalistics and financing; (c) a prototype based on the woodman architecture in one domain (seismology) to provide assurance that the architecture is valid. The key aspect is the metadata catalog. In one dimension this is described in 3 levels: (1) discovery metadata using well-known and commonly used standards such as DC (Dublin Core) to enable users (via an intelligent user interface) to search for objects within the EPOS environment relevant to their needs; (2) contextual metadata providing the context of the object described in the catalog to enable a user or the system to determine the relevance of the discovered object(s) to their requirement - the context includes projects, funding, organisations involved, persons involved, related publications, facilities, equipment etc and utilises CERIF (Common European Research Information Format) see www.eurocris.org ; (3) detailed metadata which is specific to a domain or to a particular object and includes the schema describing the object to processing software. The other dimension of the metadata concerns the objects described. These are classified into users, services (including software), data and resources (computing, data storage, instruments and scientific equipment). The core services include not only user access to data, software, services, equipment and associated processing but also facilities for interaction and cooperative working between users and storage of history and experience. EPOS will operate a full e-Science environment including metadata and persistent identifiers.

Jeffery, Keith; Michelini, Alberto; Bailo, Daniele

2013-04-01

443

Prevalence of anisotropic shell growth in rare earth core-shell upconversion nanocrystals.  

PubMed

Through a series of carefully executed experiments, we discovered the prevalence of anisotropic shell growth in many upconversion NaREF4 systems caused by a combination of factors: selective adsorption of ligands on the core surface due to the core crystal structure, ligand etching, and the lattice mismatch between core and shell components. This could lead to incomplete shell formation in core-shell nanocrystals under certain conditions. Shell growth is always faster in the a and b crystallographic directions than in the c direction. In the case of a larger lattice mismatch between the core and shell, shell growth only occurs in the a and b directions resulting in an oblong core-shell structure. These findings are useful for rationalizing shell-dependent emission properties, understanding the emission mechanisms in complex core-shell nanostructures, and for creating accurate models of core-shell designs for multifunctionality and optimal performance in applications. PMID:23570424

Zhang, Chao; Lee, Jim Yang

2013-04-15

444

Highly Photosensitive PCFs with Extremely Germanium Doped Core  

NASA Astrophysics Data System (ADS)

We report about preparation and application of index guiding germanium doped microstructured fibers, special designed for Bragg grating inscription. Due to their maximum germanium oxide concentration of 36 mol% they show a very high photosensitivity. The core diameters of the PCFs were variied between 1.6 and 6.6 ?m by changing the fiber diameters. For small core PCF preparation we integrated an additional microstructured cane overcladding step. The cores are about at half total diameter doped with germanium. The holey silica claddings are arranged in a five ring hexagonal package with a hole-pitch ratio of about 0.9 and 0.3. So we can vary the inscription efficiency of Ge doped PCFs. In difference to other highly doped or non-silica PCFs with highly polarizable and probably photosensitive core components, e.g. PCFs with lanthanum glass core, germanium doped PCFs show beside their high photosensitivity a low spectral loss. Measured with an unstructured fiber the highly germanium doped silica core material exhibits a minimum loss of about 6.5 dB/km. Inserted in the PCF structure the attenuation is increased to about 40 dB/km at a wavelength of 1.2 ?m for the large core PCF. The small core PCF show an increased loss level in the hundred dB/km range. This effect is caused, as well as the increase of hydroxide impurification during the partial ``atmospheric'' PCF preparation procedure, by structural imperfections of the designed PCFs. The high germanium concentration in the central core region allows a suitable Bragg grating inscription.

Schuster, K.; Kobelke, J.; Wang, Y.; Schwuchow, A.; Kirchhof, J.; Bartelt, H.; Pissadakis, S.

2010-11-01

445

Power optimization of variable voltage core-based systems  

Microsoft Academic Search

The growing class of portable systems, such as personal computing and communication devices, has resulted in a new set of system design requirements, mainly characterized by dominant importance of power minimization and design reuse. We develop the design methodology for the low power core-based real-time system-on-chip based on dynamically variable voltage hardware. The key challenge is to develop effective scheduling

Inki Hong; Darko Kirovski; Gang Qu; Miodrag Potkonjak; Mani B. Srivastava

1998-01-01

446

Design review report for the hydrogen interlock preliminary design  

SciTech Connect

This report documents the completion of a preliminary design review for the hydrogen interlock. The hydrogen interlock, a proposed addition to the Rotary Mode Core Sampling (RMCS) system portable exhauster, is intended to support core sampling operations in waste tanks requiring flammable gas controls. The objective of this review was to validate basic design assumptions and concepts to support a path forward leading to a final design. The conclusion reached by the review committee was that the design was acceptable and efforts should continue toward a final design review.

Corbett, J.E.

1996-01-01

447

A Performance/Energy Analysis and Optimization of Multi-Core Architectures with Voltage Scaling Techniques  

NASA Astrophysics Data System (ADS)

In this paper, we develop asymptotic analysis and simulation models to better understand the characteristics of performance and energy consumption in a multi-core processor design in which dynamic voltage scaling is used. Our asymptotic model is derived using Amdahl's law, Rent's rule and power equations to derive the optimum number of cores and their voltage levels. Our model can predict the possible impact of different multi-core processor configurations on the performance and energy consumption for given workload characteristics (e.g. available parallelism) and process technology parameters (e.g. ratios of dynamic and static energies to total energy). Through the asymptotic analysis and optimization based on the models, we can observe an asymptotic relationship between design parameters such as “the number of cores,” “core size” and “voltage scaling strategies” of a multi-core architecture with regards to performance and energy consumption at an initial phase of the design.

Lee, Jeong-Gun; Shin, Wook; Kim, Suk-Jin; Jung, Eun-Gu

448

Convection in the inner core  

NASA Astrophysics Data System (ADS)

Over the past two decades it has been debated if and why convection in the inner core might occur. Here we present a parameterized model for the thermal history of the inner core illustrating that convection is expected over a wide range of parameters. For a thermal conductivity of 36 W/Km, the critical CMB heat flux for convection is around 4 TW. A heat flux greater than 5.5 TW maintains convection in the inner core until the present day. In our model the growth of the inner core is calculated using a constant CMB heat flux. Latent and gravitational heat releases are incorporated. The temperature at the ICB is fixed by the liquidus. As the interior of the inner core cools, convection develops when the heat flux from the inner core exceeds the heat flux conducted down the adiabatic gradient. Fast growth during the early history of the inner core means that conduction alone is not sufficient to remove the heat. The convective heat flux is determined from the superadiabatic temperature gradient using a well-established relationship between the Rayleigh number (Ra) and the Nusselt number (Nu). Both the CMB heat flux and the physical parameters of iron at inner core conditions are poorly known, so we present a suite of solutions for a range of parameter values. The figure below shows the inner-core radius at which convection terminates for different choices of thermal conductivity and CMB heat flux. Convection is sustained for more of the inner-core history when thermal conduction is weak, or the growth rate is fast due to high CMB heat flux. The parameterized results are compared to numerical solutions using CitcomS. The numerical calculation illustrates how instabilities are formed close to the ICB and cause downwellings. Thermal convection can be suppressed prematurely (relative to the results shown in the figure) by a stable compositional gradient. Solidification excludes light elements from the inner core, causing the outer core to become more enriched in light elements. A stable compositional stratification develops when the composition of the crystallizing solid is proportion to the composition of the liquid. We predict the termination of convection when the stable compositional gradient suppresses the development of thermal instabilities at the inner-core boundary. Representative results suggest that convection is terminated for all but the highest values of CMB heat flow (for the above example, the critical heat flux for present day convection shifts from 5.5. TW to about 10 TW).

Cottaar, S.; Buffett, B. A.

2010-12-01

449

Evolution of First Cores and Formation of Stellar Cores in Rotating Molecular Cloud Cores  

NASA Astrophysics Data System (ADS)

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.

Saigo, Kazuya; Tomisaka, Kohji; Matsumoto, Tomoaki

2008-02-01

450

Neutral Nuclear Core VS Super Charged One  

NASA Astrophysics Data System (ADS)

Based on the Thomas-Fermi approach, we describe and distinguish the electron distributions around extended nuclear cores: (i) in the case that cores are neutral for electrons bound by protons inside cores and proton and electron numbers are the same; (ii) in the case that super charged cores are bare, electrons (positrons) produced by vacuum polarization are bound by (fly into) cores (infinity).

Rotondo, M.; Ruffini, R.; Xue, S.-S.

2008-09-01

451

HOW STARLESS ARE STARLESS CORES?  

SciTech Connect

In this paper, we present the results of Combined Array for Research in Millimeter-wave Astronomy continuum and spectral line observations of the dense core Per-Bolo 45. Although this core has previously been classified as starless, we find evidence for an outflow and conclude that Per-Bolo 45 is actually an embedded, low-luminosity protostar. We discuss the impact of newly discovered, low-luminosity, embedded objects in the Perseus molecular cloud on starless core and protostar lifetimes. We estimate that the starless core lifetime has been overestimated by 4%-18% and the Class 0/I protostellar lifetime has been underestimated by 5%-20%. Given the relatively large systematic uncertainties involved in these calculations, variations on the order of 10% do not significantly change either core lifetimes or the expected protostellar luminosity function. Finally, we suggest that high-resolution (sub)millimeter surveys of known cores lacking near-infrared and mid-infrared emission are necessary to make an accurate census of starless cores.

Schnee, Scott; Friesen, Rachel [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Di Francesco, James; Johnstone, Doug [National Research Council Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road Victoria, BC V9E 2E7 (Canada); Enoch, Melissa [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Sadavoy, Sarah, E-mail: sschnee@nrao.edu [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 1A1 (Canada)

2012-01-20

452

Viscosity of Earth's Outer Core  

NASA Astrophysics Data System (ADS)

The viscosity of Earth's outer liquid core is a fundamental property of great importance in modelling Earth's magnetic field and in many other branches of geophysics and geochemistry. Accurate measurements of viscosity in the F-layer at the bottom of the outer core are provided by the reduction of rotational splitting of the two equatorial translational modes of the inner core, observed with a network of superconducting gravimeters. Independent values are given by the prograde and retrograde modes which differ by about 10%, with a mean value of 1.243× 1011 Pa· s. At the top of the outer core, the viscosity has been measured by the free decays found, for both the retrograde and prograde Free Core Nutations, in the VLBI nutation series provided by Goddard Space Flight Center and the United States Naval Observatory. The four values range just over a factor of two, with a mean value of 2,448 Pa· s. Recently, viscosities ranging from 1011 Pa· s at the bottom of the liquid outer core to 102 Pa· s at the top have been found by Arrhenius extrapolation of laboratory measurements (Brazhkin, JETP Lett. 68, 502, 1998). We report here the results of a similar extrapolation along the melting temperature curve between our measured boundary values to obtain a viscosity profile for the entire outer liquid core.

Palmer, A.; Smylie, D. E.

2006-05-01

453

Pressure coring provides innovative approach  

SciTech Connect

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 drilling, corring, logging and production data, the engineer can determine the best possible values for tertiary recovery project evaluation. During late 1979, Gruy Federal Inc., under contract to DOE, participated with the operator in pressure coring operations in Texas Pacific Bru No. 310, Bennett Ranch unit, Wasson field, W. Texas. Engineers planned the well as part of a program to continue development of the waterflood unit on 20-acre spacing. In all, workers cut 26 cores over a 210-ft interval of the San Andres dolomite. The cored interval extended 50 feet below the estimated original oil-water contact, allowing evaluation for CO/sub 2/ floodable oil saturation in the transition zone. Analysis of the pressure coring data provided valuable information that could not be obtained from conventional cores or logs. 14 references.

Swift, T.E.; Kumar, R.; Goodrich, J.; McCoy, R.L.

1981-08-01

454

The Moon at its Core  

NASA Astrophysics Data System (ADS)

Ever since Apollo astronauts picked up rock samples and started to collect geophysical data from the Moon, evidence has been growing for a small lunar core. The most recent news comes from the Lunar Prospector magnetometer team of Lon Hood (University of Arizona), David Mitchell and Robert Lin (University of California, Berkeley), Mario Acuna (NASA Goddard Space Flight Center), and Alan Binder (Lunar Research Institute). Using the spacecraft's on-board instruments, they measured Earth's magnetic field paying particular attention to the slight alterations caused by the Moon. The data were collected in April 1998 while the Moon swung through the north tail lobe of Earth's magnetosphere. The spacecraft magnetometer detected changes in Earth's magnetic field thus giving the researchers the information they needed to estimate the size of the Moon's core. That size came out to be very small. Hood and his collaborators report a lunar core radius of only 340 km +- 90 km. For an iron-rich composition, a core of this size represents merely 1 to 3% of the Moon's total mass. In contrast, Earth's core is about 33% of our planet's total mass. This new evidence for a small lunar core strengthens the popular giant impact hypothesis which says that the Moon formed from hot, rocky debris after a Mars-sized object smashed into the early Earth. Down to its very core, the Moon has a unique history in our Solar System.

Martel, L. M. V.

1999-09-01

455

Bent core liquid crystal elastomers  

SciTech Connect

Liquid crystal (LC) elastomers with bent-core side-groups incorporate the properties of bent-core liquid crystals in a flexible and self-supporting polymer network. Bent-core liquid crystal elastomers (BCEs) with uniform alignment were prepared by attaching a reactive bent-core LC to poly(hydrogenmethylsiloxane) and crosslinking with a divinyl crosslinker. Phase behavior studies indicate a nematic phase over a wide temperature range that approaches room temperature, and thermoelastic measurements show that these BCEs can reversibly change their length by more than a factor of two upon heating and cooling. Small-angle X-ray scattering studies reveal multiple, broad low-angle peaks consistent with short-range smectic C order of the bent-core side groups. A comparison of these patterns with predictions of a Landau model for short-range smectic C order shows that the length scale for smectic ordering in BCEs is similar to that seen in pure bent-core LCs. The combination of rubber elasticity and smectic ordering of the bent-core side groups suggests that BCEs may be promising materials for sensing, actuating, and other advanced applications.

Verduzco, R.; DiMasi, E.; Luchette, P.; Ho Hong, S.; Harden, J.; Palffy-Muhoray, P.; Kilbey II, S.M.; Sprunt, S.; Gleeson, G.T. Jakli, A.

2010-07-28

456

Pressurized core barrel for sampling gas-charged marine sediments  

SciTech Connect

This paper describes a recently developed pressurized core barrel which can sample gas-charged sediments and maintain them at the downhole pressure for subsequent testing. The pressurized samples are placed in a hyperbaric chamber manned by geotechnically trained ''divers''. Here, various tests are performed on the samples at the downhole pressure. These tests include undrained shear strength and gas content determinations. Additional tests, such as consolidation and triaxial compression, are performed by mounting samples in pressurized test devices which are then passed out of the hyperbaric chamber. The pressurized core barrel was designed to be operated in a standard geotechnical borehole. A discussion of the design features is presented.

Denk, E.W.; Dunlap, W.A.; Bryant, W.R.; Milberger, L.J.; Whelan, T.J. III

1981-01-01

457

High-voltage air-core pulse transformers  

SciTech Connect

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)

Rohwein, G.J.

1981-08-01

458

PRESTELLAR CORES IN THE COALSACK  

SciTech Connect

We present high spectral resolution millimeter mapped observations of seven prestellar cores in the Coalsack, including imaging in five optically thin molecular species of the kinematic structure of two of the densest cores, C2 and C4. Various collapse-critical indices are calculated; critical masses needed for collapse are consistently greater than those observed, the latter ranging from 0.4 to 2.4 M{sub sun}. The molecular emission in several of the cores shows line profiles with infall characteristics as well as elongated areas of increased line widths and reversals of center velocity gradients, implying that accretion disks may be forming.

Saul, M.; Cunningham, M. [School of Physics, University of New South Wales, Sydney, 2052 NSW (Australia); Rathborne, J. [Departamento de Astronomia, Las Condes, Santiago (Chile); Walsh, W. [Harvard Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Butner, H. M., E-mail: msaul@phys.unsw.edu.au, E-mail: mariac@phys.unsw.edu.au, E-mail: rathborn@das.uchile.cl, E-mail: wwalsh@cfa.harvard.edu, E-mail: butnerhm@jmu.edu [Department of Physics and Astronomy, James Madison University, Harrisonburg, VA 22807 (United States)

2011-09-10

459

Prestellar Cores in the Coalsack  

NASA Astrophysics Data System (ADS)

We present high spectral resolution millimeter mapped observations of seven prestellar cores in the Coalsack, including imaging in five optically thin molecular species of the kinematic structure of two of the densest cores, C2 and C4. Various collapse-critical indices are calculated; critical masses needed for collapse are consistently greater than those observed, the latter ranging from 0.4 to 2.4 M sun. The molecular emission in several of the cores shows line profiles with infall characteristics as well as elongated areas of increased line widths and reversals of center velocity gradients, implying that accretion disks may be forming.

Saul, M.; Cunningham, M.; Rathborne, J.; Walsh, W.; Butner, H. M.

2011-09-01

460

Bent-core alignment layers  

NASA Astrophysics Data System (ADS)

The difficulty of aligning bent-core liquid crystals at a surface is addressed from three directions: We form Langmuir monolayers of bent core molecules at the air-water interface, and explore their orientation and packing. We transfer these films by Langmuir-Schaefer techniques to a solid surface, and test them for the alignment of bulk liquid crystal. We use atomistic molecular dynamics simulations to directly probe possible molecular orientation at the water surface, for comparison with experiments. We find that relatively small changes in the bent-core molecule affect both the stability of the films and their ability to promote alignment within liquid crystal cells.

Mann, Elizabeth K.; Iglesias, Wilder; Smith, Timothy; Basnet, Prem; Lacks, Daniel J.; Jákli, Antal

2011-02-01

461

SCDAP/RELAP5 Lower Core Plate Model  

SciTech Connect

The SCDAP/RELAP5 computer code is a best-estimate analysis tool for performing nuclear reactor severe accident simulations. This report describes the justification, theory, implementation, and testing of a new modeling capability which will refine the analysis of the movement of molten material from the core region to the vessel lower head. As molten material moves from the core region through the core support structures it may encounter conditions which will cause it to freeze in the region of the lower core plate, delaying its arrival to the vessel head. The timing of this arrival is significant to reactor safety, because during the time span for material relocation to the lower head, the core may be experiencing steam-limited oxidation. The time at which hot material arrives in a coolant-filled lower vessel head, thereby significantly increasing the steam flow rate through the core region, becomes significant to the progression and timing of a severe accident. This report is a revision of a report INEEL/EXT-00707, entitled "Preliminary Design Report for SCDAP/RELAP5 Lower Core Plate Model".

Coryell, Eric Wesley; Griffin, F. P.

1999-10-01

462

SCDAP/RELAP5 lower core plate model  

SciTech Connect

The SCDAP/RELAP5 computer code is a best-estimate analysis tool for performing nuclear reactor severe accident simulations. This report describes the justification, theory, implementation, and testing of a new modeling capability which will refine the analysis of the movement of molten material from the core region to the vessel lower head. As molten material moves from the core region through the core support structures it may encounter conditions which will cause it to freeze in the region of the lower core plate, delaying its arrival to the vessel head. The timing of this arrival is significant to reactor safety, because during the time span for material relocation to the lower head, the core may be experiencing steam-limited oxidation. The time at which hot material arrives in a coolant-filled lower vessel head, thereby significantly increasing the steam flow rate through the core region, becomes significant to the progression and timing of a severe accident. This report is a revision of a report INEEL/EXT-00707, entitled ``Preliminary Design Report for SCDAP/RELAP5 Lower Core Plate Model''.

Coryell, E.W.; Griffin, F.P.

1999-09-01

463

Morphological instability of core-shell metallic nanoparticles  

NASA Astrophysics Data System (ADS)

Bimetallic nanoparticles (often known as nanoalloys) with core-shell arrangement are of special interest in several applications, such as in optics, catalysis, magnetism, and biomedicine. Despite wide interest in applications, the physical factors stabilizing the structures of these nanoparticles are still unclear to a great extent, especially for what concerns the relationship between geometric structure and chemical ordering patterns. Here global-optimization searches are performed in order to single out the most stable chemical ordering patterns corresponding to the most important geometric structures, for a series of weakly miscible systems, including AgCu, AgNi, AgCo, and AuCo. The calculations show that (i) the overall geometric structure of the nanoalloy and the shape and placement of its inner core are strictly correlated; (ii) centered cores can be obtained in icosahedral nanoparticles but not in crystalline or decahedral ones, in which asymmetric quasi-Janus morphologies form; (iii) in icosahedral nanoparticles, when the core exceeds a critical size, a new type of morphological instability develops, making the core asymmetric and extending it towards the nanoparticle surface; (iv) multicenter patterns can be obtained in polyicosahedral nanoalloys. Analogies and differences between the instability of the core in icosahedral nanoalloys and the Stranski-Krastanov instability occurring in thin-film growth are discussed. All these issues are crucial for designing strategies to achieve effective coatings of the cores.

Bochicchio, Davide; Ferrando, Riccardo

2013-04-01

464

MIMI: multimodality, multiresource, information integration environment for biomedical core facilities.  

PubMed

The rapid expansion of biomedical research has brought substantial scientific and administrative data management challenges to modern core facilities. Scientifically, a core facility must be able to manage experimental workflow and the corresponding set of large and complex scientific data. It must also disseminate experimental data to relevant researchers in a secure and expedient manner that facilitates collaboration and provides support for data interpretation and analysis. Administratively, a core facility must be able to manage the scheduling of its equipment and to maintain a flexible and effective billing system to track material, resource, and personnel costs and charge for services to sustain its operation. It must also have the ability to regularly monitor the usage and performance of its equipment and to provide summary statistics on resources spent on different categories of research. To address these informatics challenges, we introduce a comprehensive system called MIMI (multimodality, multiresource, information integration environment) that integrates the administrative and scientific support of a core facility into a single web-based environment. We report the design, development, and deployment experience of a baseline MIMI system at an imaging core facility and discuss the general applicability of such a system in other types of core facilities. These initial results suggest that MIMI will be a unique, cost-effective approach to addressing the informatics infrastructure needs of core facilities and similar research laboratories. PMID:17999114

Szymanski, Jacek; Wilson, David L; Zhang, Guo-Qiang

2007-11-13

465

Foam core materials for structural sandwich panels  

SciTech Connect

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.

Huang Jongshin.

1991-01-01

466

Union soluble oil flood in El Dorado cores  

SciTech Connect

Results are presented of laboratory experiments using Union's soluble oil flood process in El Dorado cores. The core flood is to provide complete information on fluid compositions and phase behavior of the effluents such that adequate core flood match using the chemical flood simulator can be made. This step is essential for evaluating reservoir performance on the South Pattern of the El Dorado Micellar-Polymer Project. The results show the caustic preflush in the flood process causes face plugging of the field cores. The problem was controlled by using chelating agents along with the caustic fluid to keep divalent cations in solution. The required amount of chelating agent was determined to be ca 25 times as strong as the original design for the field test. Liquid chromatography analysis of sulfonate provides valuable information on selective fractionation of monosulfonate in the micellar fluid. 10 references.

Chiou, C.S.

1983-02-01

467

Summary of multi-core hardware and programming model investigations  

SciTech Connect

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.

Kelly, Suzanne Marie; Pedretti, Kevin Thomas Tauke; Levenhagen, Michael J.

2008-05-01

468

Analysis and Application of the Series Core Snubber  

NASA Astrophysics Data System (ADS)

The transformer core snubber (CS), as one of the most important components in the EAST (experimental advanced superconducting tokamak) NBI (neutral beam injector) system, is designed to limit grid damage and protect the ion source during periods of electrical breakdowns. A transformer core snubber is analyzed in detail in this paper. Several kinds of soft magnetic cores are presented and compared. With analysis and experiment on the basic characteristics of the cores, the most suitable materials are suggested. The circuit simulation code is established which could simulate faulty conditions with concentrated and distributed CS concepts. Based on the above work, an ion source CS is developed with series type of distributed topology. The CS has been subjected to experimental validation at 80 kV with a peak short-current of approximately 400 A in a real NBI system, which proves the accuracy of the adopted assumptions and the analysis method.

Xie, Fei; Li, Ge; Cheng, Desheng; Chen, Qiangjian

2013-05-01

469

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

NASA Astrophysics Data System (ADS)

The authors summarize the results of detailed neutronic and thermal-hydraulic evaluations of the heat pipe cooled thermionic (HPTI) reactor design, identify its key design attributes, and quantify its performance