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1

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

2

Air Core Pulse Transformer Design.  

National Technical Information Service (NTIS)

Cylindrical air core pulse transformers capable of passing high voltage/energy pulse waveforms with high efficiency and low distortion require a much more delicate design balance of physical dimensions and electrical parameters than iron or ferrite core u...

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

1988-01-01

3

Accelerator driven systems for transmutation: Fuel development, design and safety  

Microsoft Academic Search

European R&D for ADS design and fuel development is driven in the 6th FP of the EU by the EUROTRANS Programme. In EUROTRANS two ADS design routes are followed, the XT-ADS and the EFIT. The XT-ADS is designed to provide the experimental demonstration of transmutation. The EFIT, the European Facility for Industrial Transmutation, aims at a conceptual design of a

W. Maschek; X. Chen; F. Delage; A. Fernandez-Carretero; D. Haas; C. Matzerath Boccaccini; A. Rineiski; P. Smith; V. Sobolev; R. Thetford; J. Wallenius

2008-01-01

4

Air core pulse transformer design  

Microsoft Academic Search

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

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

1988-01-01

5

FabScalar: Automating Superscalar Core Design  

Microsoft Academic Search

Providing multiple superscalar core types on a chip, each tailored to different classes of instruction-level behavior, is an exciting direction for increasing processor performance and energy efficiency. Unfortunately, processor design and verification effort increases with each additional core type, limiting the microarchitectural diversity that can be practically implemented. FabScalar aims to automate superscalar core design, opening up processor design to

Niket K. Choudhary; Salil V. Wadhavkar; Tanmay A. Shah; Hiran Mayukh; Jayneel Gandhi; Brandon H. Dwiel; Sandeep Navada; Hashem H. Najaf-abadi; Eric Rotenberg

2012-01-01

6

Conceptual study of advanced PWR core design.  

National Technical Information Service (NTIS)

The purpose of this project is for developing and verifying the core design concepts with enhanced safety and economy, and associated methodologies for core analyses. From the study of the sate-of-art of foreign advanced reactor cores, we developed core c...

H. K. Joo K. K. Kim M. H. Chang Y. I. Kim Y. J. Kim

1997-01-01

7

Concept Design of Advanced Marine Reactor (1), Core Design. Design Study for Optimized Core.  

National Technical Information Service (NTIS)

We started the design study of the concept design of the Advanced Marine Reactor from FY 1987, and we researched and studied as for the optimization of the core and the components of the 100 MWt reactor plant that main research thema was minituarization a...

N. Ambo T. Yokomura

1989-01-01

8

Heavy water breeder conceptual core design  

Microsoft Academic Search

A reference design was developed for a close packed pressurized heavy water cooled and moderated breeder core, operating on the uranium plutonium cycle. The seed-blanket concept was found to be most advantageous. The core is composed of a large number of identical seed-blanket units, each of which is controlled by moving the seed, which is zoned in such a way

Radkowsky

1981-01-01

9

Study of compact fast reactor core designs  

SciTech Connect

A study is conducted to investigate conceptual liquid-metal reactor (LMR) core concepts, employing some unconventional design features for improved economics and safety. The unconventional design elements are used to supplement the conventional measures, which alone have apparently not led to an attractive LMR design for the 21st century. Better economics are obtained through simplicity and compactness of the core design. For simplicity, internal scattered blankets are omitted. Core compactness is achieved by maximum power flattening, resulting from axial and radial enrichment zones along with axial and radial (BeO) reflectors. To further enhance core compactness, the in-core compactness, the in-core control rods are replaced by reflector controls. For improved safety, the general objective is to reduce both coolant-void and burnup reactivities. However, even with the use of a wide spectrum of unconventional design features, such as burnable poisons, peripheral reflectors, and inner moderating regions, it is not possible to overcome the fact that both coolant-void and burnup reactivities cannot be reduced simultaneously to desirably low levels. The only resolution of this dilemma appears to be minimize coolant-void reactivity and to manage the burnup reactivities. However, even with the use of a wide spectrum of unconventional design features, such as burnable poisons, peripheral reflectors, and inner moderating regions, it is not possible to overcome the fact that both coolant-void and burnup reactivities cannot be reduced simultaneously to desirably low levels. The only resolution of this dilemma appears to be to minimize coolant-void reactivity and to manage the burnup reactivity losses, such that an accidental insertion of significant amounts of reactivity is mechanically not possible. A conceptual design with these characteristics is described.

Hamid, T.; Ott, K.O. (Purdue Univ., West Lafayette, IN (United States))

1993-02-01

10

Energy Efficient Engine core design and performance report  

NASA Technical Reports Server (NTRS)

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. Marshall

1982-01-01

11

Overview of core designs and requirements/criteria for core restraint systems  

SciTech Connect

The requirements and lifetime criteria for the design of a Liquid Metal Fast Breeder Reactor (LMFBR) Core Restraint System are presented. A discussion of the three types of core restraint systems used in LMFBR core design is given. Details of the core restraint system selected for FFTF are presented and the reasons for this selection given. Structural analysis procedures being used to manage the FFTF assembly irradiations are discussed. Efforts that are ongoing to validate the calculational methods and lifetime criteria are presented.

Sutherland, W.H.

1984-09-01

12

Learn from the Core--Design from the Core  

ERIC Educational Resources Information Center

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

Ockerse, Thomas

2012-01-01

13

Core refueling subsystem design description. Revision 1  

SciTech Connect

The Core Refueling Subsystem of the Fuel Handling and Storage System provides the mechanisms and tools necessary for the removal and replacement of the hexagonal elements which comprise the reactor core. The Core Refueling Subsystem is not "safety-related." The Core Refueling Subsystem equipment is used to prepare the plant for element removal and replacement, install the machines which handle the elements, maintain control of air inleakage and radiation release, transport the elements between the core and storage, and control the automatic and manual operations of the machines. Much of the element handling is performed inside the vessel, and the entire exchange of elements between storage and core is performed with the elements in a helium atmosphere. The core refueling operations are conducted with the reactor module shutdown and the primary coolant pressure slightly subatmospheric. The subsystem is capable of accomplishing the refueling in a reliable manner commensurate with the plant availability requirements.

Anderson, J.K.; Harvey, E.C.

1987-07-01

14

Experiences with Soft-Core Processor Design  

Microsoft Academic Search

Soft-core processors exploit the flexibility of Field Pro- grammable Gate Arrays (FPGAs) to allow a system de- signer to customize the processor to the needs of a target application. This paper describes the UT Nios implementa- tion of Altera's Nios architecture. A benchmark set appro- priate for soft-core processors is defined. Using the bench- mark set, the performance of UT

Franjo Plavec; Blair Fort; Zvonko G. Vranesic; Stephen Dean Brown

2005-01-01

15

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

16

Advanced neutron source final preconceptual reference core design  

Microsoft Academic Search

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

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

1989-01-01

17

Rapid design of application specific FFT cores  

Microsoft Academic Search

Methods are presented for developing synthesizable FFT cores. These are based on a modular approach in which parameterized commutator and processor blocks are cascaded to implement the computations required in many important FFT signal flow graphs. In addition, it is shown how the use of a digital serial data organization can be used to produce systems that offer 100% processor

Tiong Jiu Ding; John V. McCanny; Yi Hu

1999-01-01

18

A Tight Lattice, Epithermal Core Design for the Integral PWR  

Microsoft Academic Search

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

J. G. B. Saccheri; N. E. Todreas; M. J. Driscoll

2004-01-01

19

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

20

Design of an LEU core for the MIT reactor  

SciTech Connect

A design of the MIT Reactor core using monolithic U-7Mo LEU fuel has been developed with the goal of maintaining thermal and fast neutron fluxes as well as increasing the flexibility for meeting the needs of in-core experiments. An optimum core was sought by varying the core materials, and fuel plate numbers and thicknesses, but maintaining the outside dimensions of a fuel element. A full-core model of the MITR by the Monte-Carlo transport code MCNP was used to calculate the neutron fluxes, reactivity and neutron spectrum available for experiments. The optimum reactor design consisted of the use of half-sized fuel elements made up of nine U-7Mo LEU fuel plates of 0.55 mm thickness with 0.25 mm finned aluminum cladding. This design also utilized solid beryllium fuel elements (dummies) with boron fixed absorbers or solid lead dummies, depending on the in-core experiment flux and spectrum needs. Because the new core design contains twice the amount of 235 U as does the existing HEU core, and produces much more Pu, its fuel cycle length is twice as long at the same power level. Preliminary thermal-hydraulic and neutronic safety evaluations indicate superior performance to the current HEU fuel. (authors)

Newton, T. [Massachusetts Inst. of Technology, Nuclear Reactor Laboratory, 138 Albany St., Cambridge, MA 02139 (United States); Kazimi, M.; Pilat, E. [Nuclear Science and Engineering Dept., 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

2006-07-01

21

Design and fabrication of integrated solenoid inductors with magnetic cores  

Microsoft Academic Search

Integrated solenoid inductors with magnetic core were designed and fabricated. An inductance above 70 nH was achieved while keeping the coil resistance below 1 Omega and the device area below 1 mm2. The inductance of the magnetic inductor was more than 30 times that of the air core inductor of the identical geometry, and the inductance density reached above 200

Dok Won Lee; Kyu-Pyung Hwang; Shan X. Wang

2008-01-01

22

De novo design of the hydrophobic cores of proteins.  

PubMed Central

We have developed and experimentally tested a novel computational approach for the de novo design of hydrophobic cores. A pair of computer programs has been written, the first of which creates a "custom" rotamer library for potential hydrophobic residues, based on the backbone structure of the protein of interest. The second program uses a genetic algorithm to globally optimize for a low energy core sequence and structure, using the custom rotamer library as input. Success of the programs in predicting the sequences of native proteins indicates that they should be effective tools for protein design. Using these programs, we have designed and engineered several variants of the phage 434 cro protein, containing five, seven, or eight sequence changes in the hydrophobic core. As controls, we have produced a variant consisting of a randomly generated core with six sequence changes but equal volume relative to the native core and a variant with a "minimalist" core containing predominantly leucine residues. Two of the designs, including one with eight core sequence changes, have thermal stabilities comparable to the native protein, whereas the third design and the minimalist protein are significantly destabilized. The randomly designed control is completely unfolded under equivalent conditions. These results suggest that rational de novo design of hydrophobic cores is feasible, and stress the importance of specific packing interactions for the stability of proteins. A surprising aspect of the results is that all of the variants display highly cooperative thermal denaturation curves and reasonably dispersed NMR spectra. This suggests that the non-core residues of a protein play a significant role in determining the uniqueness of the folded structure.

Desjarlais, J. R.; Handel, T. M.

1995-01-01

23

Study of a new compact fast reactor core design  

SciTech Connect

A study was conducted to investigate conceptual Liquid Metal Reactor (LMR) designs, employing some unconventional design features, for improved economics and safety. The unconventional design elements were used to supplement the conventional design measures, which alone did not lead to a truly competitive LMR design. Better economics was obtained through simplicity and compactness of core design. For simplicity of core design, internal blankets were omitted. Core compactness was achieved by maximum power flattening. This was done by employing axial and radial enrichment zones along with axial and radial (BeO) reflectors. To further enhance core compactness, the in-core control rods were replaced by reflector controls. For improved safety, the objective was to reduce both coolant void and burnup reactivities. However, even with the use of a wide spectrum of unconventional design features, such as burnable poisons, peripheral reflectors and inner moderating regions, it was not possible to overcome the classical known fact that both coolant void and burnup reactivities cannot be reduced simultaneously. The only resolution of this dilemma appeared to be to minimize coolant void reactivity, and to manage the burnup reactivity losses, such that an accidental insertion of significant amounts of reactivity is mechanically not possible. A conceptual design with these characteristics is described in this thesis.

Hamid, T.

1990-01-01

24

Verifying IP-core based system-on-chip designs  

Microsoft Academic Search

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

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

1999-01-01

25

GFR fuel and core pre-conceptual design studies  

SciTech Connect

The revision of the GFR core design - plate type - has been undertaken since previous core presented at Global'05. The self-breeding searched for has been achieved with an optimized design ('12/06 E'). The higher core pressure drop was a matter of concern. First of all, the core coolability in natural circulation for pressurized conditions has been studied and preliminary plant transient calculations have been performed. The design and safety criteria are met but no more margin remains. The project is also addressing the feasibility and the design of the fuel S/A. The hexagonal shape together with the principle of closed S/A (wrapper tube) is kept. Ceramic plate type fuel element combines a high enough core power density (minimization of the Pu inventory) and plutonium and minor actinides recycling capabilities. Innovative for many aspects, the fuel element is central to the GFR feasibility. It is supported already by a significant R and D effort also applicable to a pin concept that is considered as the other fuel element of interest. This combination of fuel/core feasibility and performance analysis, safety dispositions and performances analysis will compose the 'GFR preliminary feasibility' which is a project milestone at the end of the year 2007. (authors)

Chauvin, N.; Ravenet, A.; Lorenzo, D.; Pelletier, M.; Escleine, J.M.; Munoz, I.; Bonnerot, J.M. [CEA/DEN/DEC, CEA Cadarache, 13108 Saint-Paul-lez-Durance (France); Malo, J.Y.; Garnier, J.C.; Bertrand, F.; Bosq, J.C. [CEA/DEN/DER, CEA Cadarache, 13108 Saint-Paul-lez-Durance (France)

2007-07-01

26

Design analysis of core assemblies for supercritical pressure conditions  

Microsoft Academic Search

The increase of steam parameters to supercritical conditions could reduce the power generating costs of light water reactors significantly [Proceedings of SCR-2000 (2000) 1]. Core assemblies, however, will differ from current BWR or PWR design. In this context, this paper summarizes the main results related to a thermal-hydraulic design analysis of applicable fuel assemblies. Starting from a thorough literature survey

X. Cheng; T. Schulenberg; D. Bittermann; P. Rau

2003-01-01

27

Design. Youth Training Scheme. Core Exemplar Work Based Project.  

ERIC Educational Resources Information Center

This trainer's guide is intended to assist supervisors of work-based career training projects in helping students understand the importance of industrial designers and the stages of the industrial design process. The guide is one in a series of core curriculum modules that is intended for use in combination on- and off-the-job programs to…

Further Education Staff Coll., Blagdon (England).

28

Fuel, Core Design and Subchannel Analysis of a Superfast Reactor  

Microsoft Academic Search

A compact supercritical water-cooled fast reactor (superfast reactor) core with a power of 700MWe is designed by using a three-dimensional neutronics thermal-hydraulic coupled method. The core consists of 126 seed assemblies and 73 blanket assemblies. In the seed assemblies, 251 fuel rods, consisting of MOX pellets, stainless steel (SUS304) cladding, and fission gas plenum are arranged into a tight triangle

Liangzhi CAO; Yoshiaki OKA; Yuki ISHIWATARI; Zhi SHANG

2008-01-01

29

Design, fabrication and experiment of iron-core passive compulsator  

Microsoft Academic Search

The paper presents design, fabrication and experiments of an iron-core, rotating field, two phases and modified non-salient pole rotor compulsator (compensated pulsed alternator), which is for comparison with air-core compulsator to be made in the near future. It includes parameters and special technics different from traditional generators. The decision of thickness of compensation shield is based on the simulation of

Shaopeng Wu; Shumei Cui; Liwei Song; Manlan Liu

2008-01-01

30

Core design of the upgraded TREAT reactor  

SciTech Connect

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

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

1982-01-01

31

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

Microsoft Academic Search

Although in theory, the differences in design between fixed-core and mobile-core prostheses should influence motion restoration,\\u000a in vivo kinematic differences linked with prosthesis design remained unclear. The aim of this study was to investigate the\\u000a rationale that the mobile-core design seems more likely to restore physiological motion since the translation of the core\\u000a could help to mimic the kinematic effects

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

32

Analysis and Design of ITER 1 MV Core Snubber  

NASA Astrophysics Data System (ADS)

The core snubber, as a passive protection device, can suppress arc current and absorb stored energy in stray capacitance during the electrical breakdown in accelerating electrodes of ITER NBI. In order to design the core snubber of ITER, the control parameters of the arc peak current have been firstly analyzed by the Fink-Baker-Owren (FBO) method, which are used for designing the DIIID 100 kV snubber. The B-H curve can be derived from the measured voltage and current waveforms, and the hysteresis loss of the core snubber can be derived using the revised parallelogram method. The core snubber can be a simplified representation as an equivalent parallel resistance and inductance, which has been neglected by the FBO method. A simulation code including the parallel equivalent resistance and inductance has been set up. The simulation and experiments result in dramatically large arc shorting currents due to the parallel inductance effect. The case shows that the core snubber utilizing the FBO method gives more compact design.

Wang, Haitian; Li, Ge

2012-11-01

33

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

34

Influence Of Low Boron Core Design On PWR Transient Behavior  

SciTech Connect

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

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

2006-07-01

35

GCRA review and appraisal of HTGR reactor-core-design program. [HTGR-SC, -R, -NHSDR  

SciTech Connect

The reactor-core-design program has as its principal objective and responsibility the design and resolution of major technical issues for the reactor core and core components on a schedule consistent with the plant licensing and construction program. The task covered in this review includes three major design areas: core physics, core thermal and hydraulic performance fuel element design, and in-core fuel performance evaluation.

Not Available

1980-09-01

36

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

37

Core Design with Respect to the Safety Concept.  

National Technical Information Service (NTIS)

In the present paper the following topics are dealt with: principles of reactor core design and optimization, fuel management and safety concept for higher cycles and results of risk analyses (e.g. rod ejection, steam line break etc.). (Atomindex citation...

W. Kollmar

1981-01-01

38

Design of composite flywheel rotors with soft cores  

NASA Astrophysics Data System (ADS)

A flywheel is an inertial energy storage system in which the energy or momentum is stored in a rotating mass. Over the last twenty years, high-performance flywheels have been developed with significant improvements, showing potential as energy storage systems in a wide range of applications. Despite the great advances in fundamental knowledge and technology, the current successful rotors depend mainly on the recent developments of high-stiffness and high-strength carbon composites. These composites are expensive and the cost of flywheels made of them is high. The ultimate goal of the study presented here is the development of a cost-effective composite rotor made of a hybrid material. In this study, two-dimensional and three-dimensional analysis tools were developed and utilized in the design of the composite rim, and extensive spin tests were performed to validate the designed rotors and give a sound basis for large-scale rotor design. Hybrid rims made of several different composite materials can effectively reduce the radial stress in the composite rim, which is critical in the design of composite rims. Since the hybrid composite rims we studied employ low-cost glass fiber for the inside of the rim, and the result is large radial growth of the hybrid rim, conventional metallic hubs cannot be used in this design. A soft core developed in this study was successfully able to accommodate the large radial growth of the rim. High bonding strength at the shaft-to-core interface was achieved by the soft core being molded directly onto the steel shaft, and a tapered geometry was used to avoid stress concentrations at the shaft-to-core interface. Extensive spin tests were utilized for reverse engineering of the design of composite rotors, and there was good correlation between tests and analysis. A large-scale composite rotor for ground transportation is presented with the performance levels predicted for it.

Kim, Taehan

39

Designing an Institutional Web-based Core Facility Management System  

PubMed Central

The authors and their four institutions collaborated to (i) identify the key challenges to core facility management; (ii) identify the requirements for an effective core facility management system; (iii) design, test and deploy such a system. Through a series of interviews with all participants in the core work flow (customers, core staff, administrators), the team identified a number of key challenges, including: (i) difficulty for researchers in identifying available services; (ii) inconsistent processes for requesting services; (iii) inadequate controls for approving service requests; (iv) inefficient processes for tracking and communicating about project processes; (v) time-consuming billing practices; (vi) incomplete revenue capture; (vii) manual reporting processes. The team identified the following requirements for a system to address these challenges: (i) ability to support a broad range of core business practices such as complex quote generation and project management; calendaring/equipment reservation management; sample tracking; complex forms; and import of usage data from hardware; (ii) ability to offer services for both internal and external customers, including flexible pricing and off-site access; (iii) ability to interact with institutional financial systems (e.g. SAP, PeopleSoft, Lawson, SunGard Banner) and identify management systems (e.g. Microsoft Active Directory, LDAP, and other SAML 2.0-compliant services). The team developed and deployed this system across the collaborative partners, as well as other major research institutions.

Tabarini, D.; Clisham, S.; John, D.; Hagen, A.

2011-01-01

40

Test Wrapper Design and Optimization Under Power Constraints for Embedded Cores With Multiple Clock Domains  

Microsoft Academic Search

Even though many embedded cores contain several clock domains, most published methods for wrapper design have been limited to single-frequency cores. Cumbersome and invasive design techniques, such as insertion of test points, are needed to make these methods applicable to current-generation embedded cores. This paper presents a new method for designing test wrappers for embedded cores with multiple clock domains.

Qiang Xu; Nicola Nicolici; Krishnendu Chakrabarty

2007-01-01

41

Core compressor exit stage study. 1: Aerodynamic and mechanical design  

NASA Technical Reports Server (NTRS)

The effect of aspect ratio on the performance of core compressor exit stages was demonstrated using two three stage, highly loaded, core compressors. Aspect ratio was identified as having a strong influence on compressors endwall loss. Both compressors simulated the last three stages of an advanced eight stage core compressor and were designed with the same 0.915 hub/tip ratio, 4.30 kg/sec (9.47 1bm/sec) inlet corrected flow, and 167 m/sec (547 ft/sec) corrected mean wheel speed. The first compressor had an aspect ratio of 0.81 and an overall pressure ratio of 1.357 at a design adiabatic efficiency of 88.3% with an average diffusion factor or 0.529. The aspect ratio of the second compressor was 1.22 with an overall pressure ratio of 1.324 at a design adiabatic efficiency of 88.7% with an average diffusion factor of 0.491.

Burdsall, E. A.; Canal, E., Jr.; Lyons, K. A.

1979-01-01

42

Preliminary design study of advanced multistage axial flow core compressors  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

43

Core damage frequency (reactor design) perspectives based on IPE results  

SciTech Connect

This paper provides perspectives gained from reviewing 75 Individual Plant Examination (IPE) submittals covering 108 nuclear power plant units. Variability both within and among reactor types is examined to provide perspectives regarding plant-specific design and operational features, and C, modeling assumptions that play a significant role in the estimates of core damage frequencies in the IPEs. Human actions found to be important in boiling water reactors (BWRs) and in pressurized water reactors (PWRs) are presented and the events most frequently found important are discussed.

Camp, A.L.; Dingman, S.E.; Forester, J.A. [and others

1996-12-31

44

Fuel management strategy for the new equilibrium silicide core design of RSG GAS (MPR30)  

Microsoft Academic Search

The design procedure and fuel management strategy are described for converting the oxide core of the 30 MWth RSG GAS (MPR-30) to the new equilibrium silicide core using a higher uranium loading. A procedure to directly search for the equilibrium core has been devised and implemented in an in-core fuel management code developed for RSG GAS. Compared to the present

Liem Peng Hong; Bakri Arbie; T. M. Sembiring; P. Prayoto; R. Nabbi

1998-01-01

45

Design Core commonalities: A study of the College of Design at Iowa State University  

Microsoft Academic Search

This comprehensive study asks what a group of rather diverse disciplines have in common. It involves a cross disciplinary examination of an entire College, the College of Design at Iowa State University. This research was intended to provide a sense of direction in developing and assessing possible Core content. The reasoning was that material that is necessary to all of

Jane E. Venes

2009-01-01

46

78 FR 32988 - Core Principles and Other Requirements for Designated Contract Markets; Correction  

Federal Register 2010, 2011, 2012, 2013

...COMMISSION 17 CFR Part 38 RIN 3038-AD09 Core Principles and Other Requirements for Designated...Register release of the final rule regarding Core Principles and Other Requirements for Designated...Register release of the final rule regarding Core Principles and Other Requirements for...

2013-06-03

47

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

48

A Lightweight Pneumatic Coring Device: Design and Field Test.  

National Technical Information Service (NTIS)

A lightweight pneumatic coring device for use from relatively small research vessels was developed and field tested. The device consists of an aluminum frame supporting a core barrel surmounted by a pneumatic industrial vibrator. Tests of a number of pair...

J. A. Fuller E. P. Meisburger

1982-01-01

49

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

50

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

51

FabScalar: composing synthesizable RTL designs of arbitrary cores within a canonical superscalar template  

Microsoft Academic Search

A growing body of work has compiled a strong case for the single-ISA heterogeneous multi-core paradigm. A single-ISA heterogeneous multi-core provides multiple, differently-designed superscalar core types that can streamline the execution of diverse programs and program phases. No prior research has addressed the 'Achilles' heel of this paradigm: design and verification effort is multiplied by the number of different core

Niket K. Choudhary; Salil V. Wadhavkar; Tanmay A. Shah; Hiran Mayukh; Jayneel Gandhi; Brandon H. Dwiel; Sandeep Navada; Hashem H. Najaf-abadi; Eric Rotenberg

2011-01-01

52

The object model at the core of the IDEA+ design environment  

Microsoft Academic Search

** The IDEA+ project aims at developing an Integrated Design Environment for Architect designers, in which design tools and computational tests are gathered around and make use of one and the same core object model. This paper focuses on three different aspects in which the IDEA+ core model differs from many other product modelling research initiatives: the systematic approach in

Ann Hendricx; Herman Neuckermans

53

Core design for use with precision composite reflectors  

NASA Technical Reports Server (NTRS)

A uniformly flexible core, and method for manufacturing the same, is disclosed for use between the face plates of a sandwich structure. The core is made of a plurality of thin corrugated strips, the corrugations being defined by a plurality of peaks and valleys connected to one another by a plurality of diagonal risers. The corrugated strips are orthogonally criss-crossed to form the core. The core is particularly suitable for use with high accuracy spherically curved sandwich structures because undesirable stresses in the curved face plates are minimized due to the uniform flexibility characteristics of the core in both the X and Y directions. The core is self venting because of the open geometry of the corrugations. The core can be made from any suitable composite, metal, or polymer. Thermal expansion problems in sandwich structures may be minimized by making the core from the same composite materials that are selected in the manufacture of the curved face plates because of their low coefficients of thermal expansion. Where the strips are made of a composite material, the core may be constructed by first cutting an already cured corrugated sheet into a plurality of corrugated strips and then secondarily bonding the strips to one another or, alternatively, by lying a plurality of uncured strips orthogonally over one another in a suitable jig and then curing and bonding the entire plurality of strips to one another in a single operation.

Porter, Christopher C. (inventor); Jacoy, Paul J. (inventor); Schmitigal, Wesley P. (inventor)

1992-01-01

54

New Core Design for Use with Precision Composite Reflectors.  

National Technical Information Service (NTIS)

A uniformly flexible core, and method for manufacturing the same, is disclosed for use between the face plates of a sandwich structure. The core is made of a plurality of thin corrugated strips, the corrugations being defined by a plurality of peaks and v...

C. C. Porter P. J. Jacoy W. P. Schmitigal

1990-01-01

55

Optimization Design and Finite Element Analysis of Core Cutter  

Microsoft Academic Search

The hydro-hammer sampler is a new type of sampler compared with traditional ones. An important part of this new offshore sampler is that the structure of the core cutter has a significant effect on penetration and core recovery. In our experiments, a commercial finite element code with a capability of simulating large-strain frictional contact between two or more solid bodies

Pin-lu CAO; Kun YIN; Jian-ming PENG; Jian-lin LIU

2007-01-01

56

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

Microsoft Academic Search

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

Mitsuru KAMBE

2002-01-01

57

Voltage and frequency island optimizations for many-core\\/networks-on-chip designs  

Microsoft Academic Search

Many-core chips interconnected by networks-on-chip (NoC) are increasingly challenged by the tight power consumption constraints. The concept of voltage and frequency island (VFI) which has been recently introduced for achieving fine-grain core-level power management fits well with an NoC design style. This paper will discuss some recent advancement of VFI optimizations for many-core\\/NoC designs. We will also discuss other research

Wooyoung Jang; Duo Ding; David Z. Pan

2010-01-01

58

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

59

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

Microsoft Academic Search

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

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

60

DESIGN AND ANALYSIS OF ELECTRIC MOTORS WITH SOFT MAGNETIC COMPOSITE CORE  

Microsoft Academic Search

This paper aims to present the design aspects of electrical motors with soft magnetic composite (SMC) core. Combined classical and modern analysis procedures are proposed for developing SMC motors. A permanent magnet claw pole motor using SMC material as the stator core was firstly designed by the equivalent magnetic circuit method. Three- dimensional finite element magnetic field analysis was conducted

Y. G. Guo; J. G. Zhu; W. Wu

61

Teaching to the Common Core by Design, Not Accident  

ERIC Educational Resources Information Center

The Bill & Melinda Gates Foundation has created tools and supports intended to help teachers adapt to the Common Core State Standards in English language arts and mathematics. The tools seek to find the right balance between encouraging teachers' creativity and giving them enough guidance to ensure quality. They are the product of two years of…

Phillips, Vicki; Wong, Carina

2012-01-01

62

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

63

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

64

WCDMA multiprocessor on chip: design methodology using soft IP cores  

NASA Astrophysics Data System (ADS)

The implementation of the physical layer of W-CDMA on embedded devices requires optimizing the resources required due to the limited space and energy allowed. Although general purpose processors will eventually be embedded they are still lacking performance and more importantly they are not tailored to the computation requirements. We propose ion this paper a methodology based on multiobjective genetic algorithms to tailor soft IP processor cores for the purpose of embedding W-CDMA.

Ghali, K.; Hammami, Omar

2002-08-01

65

Effective Optimistic-Checker Tandem Core Design through Architectural Pruning  

Microsoft Academic Search

Design complexity is rapidly becoming a limiting fac- tor in the design of modern, high-performance micro- processors. This paper introduces an optimization tech- nique to improve the efficiency of complex processors. Us- ing a new metric (µUtilization), the designer can identify infrequently-used functionality which contributes little to performance and then systematically \\

Francisco J. Mesa-martinez; Jose Renau

2007-01-01

66

Effective Optimistic-Checker Tandem Core Design through Architectural Pruning  

Microsoft Academic Search

Design complexity is rapidly becoming a limiting factor in the design of modern, high-performance microprocessors. This paper introduces an optimization technique to improve the efficiency of complex processors. Using a new metric (^Utilization), the designer can identify infrequently-used functionality which contributes little to performance and then systematically \\

F. J. Mesa-Martinez; J. Renau

2007-01-01

67

Design and analysis of a thermal core for a high performance light water reactor  

Microsoft Academic Search

The High Performance Light Water Reactor is a Generation IV light water reactor concept, operated at a supercritical pressure of 25MPa with a core outlet temperature of 500°C. A thermal core design for this reactor has been worked out by a consortium of Euratom member states within the 6th European Framework Program. Aiming at peak cladding temperatures of less than

T. Schulenberg; C. Maráczy; J. Heinecke; W. Bernnat

2011-01-01

68

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

69

Explication of the Graphite Structural Design Code of core components for the High Temperature Engineering Test Reactor.  

National Technical Information Service (NTIS)

The integrity evaluation of the core graphite components for the High Temperature Engineering Test Reactor (HTTR) will be carried out based upon the Graphite Structural Design Code for core components. In the application of this design code, it is necessa...

T. Iyoku M. Ishihara J. Toyota S. Shiozawa

1991-01-01

70

Core Design and Operation Optimization Methods Based on Time-Dependent Perturbation Theory.  

National Technical Information Service (NTIS)

A general approach for the optimization of nuclear reactor core design and operation is outlined; it is based on two cornerstones: a newly developed time-dependent (or burnup-dependent) perturbation theory for nonlinear problems and a succesive iteration ...

E. Greenspan

1983-01-01

71

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

72

Rapid design of DSP ASIC cores using hierarchical VHDL libraries  

Microsoft Academic Search

Methods are presented for the rapid design of DSP ASICs based on the use of a series of hierarchical VHDL libraries which are portable across many silicon foundries. These allows complex DSP silicon systems to be developed in a small fraction of the time normally required. Resulting designs are highly competitive with those developed using more conventional methods. The approach

J. V. McCanny; Y. Hu; T. J. Ding; D. Trainor; D. Ridge

1996-01-01

73

An integrated design of SM2C core motor for vehicular applications  

Microsoft Academic Search

This paper focuses on the design and the evaluation of a three-phase permanent magnet synchronous machine (PMSM) with a stator core made of Soft Magnetic Mouldable Composite - SM2C. A radial flux PM machine with modular winding is designed for a high-speed low-voltage automotive application. Manufacturability and a high winding fill factor are vital for a low permeability stator core

Avo Reinap; Conny Högmark; Mats Alaküla; Tord Cedell; Mats Andersson

2010-01-01

74

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

Microsoft Academic Search

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

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

2004-01-01

75

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

Microsoft Academic Search

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

Mary Munson; Suganthi Balasubramanian; Karen G. Fleming; Athena D. Nagi; Ronan O'Brien; Julian M. Sturtevant; Lynne Regan

1996-01-01

76

Design and Evaluation of an Enhanced In-Vessel Core Catcher  

SciTech Connect

An enhanced in-vessel core catcher is being designed and evaluated as part of a joint United States (U.S.) - Korean International Nuclear Engineering Research Initiative (INERI) investigating methods to insure In-Vessel Retention (IVR) of core materials that may relocate under severe accident conditions in advanced reactors. To reduce cost and simplify manufacture and installation, this new core catcher design consists of several interlocking sections that are machined to fit together when inserted into the lower head. If needed, the core catcher can be manufactured with holes to accommodate lower head penetrations. Each section of the core catcher consists of two material layers with an option to add a third layer (if deemed necessary): a base material, which has the capability to support and contain the mass of core materials that may relocate during a severe accident; an oxide coating material on top of the base material, which resists interactions with high-temperature core materials; and an optional coating on the bottom side of the base material to prevent any potential oxidation of the base material during the lifetime of the reactor. This paper summarizes the status of core catcher design and evaluation efforts, including analyses, materials interaction tests, and prototypic testing efforts.

Joy L. Rempe

2004-06-01

77

Design and fabrication of ultra-low crosstalk and low-loss multi-core fiber  

NASA Astrophysics Data System (ADS)

We designed and fabricated a multi-core fiber (MCF) in which seven identical trench-assisted pure-silica cores were arranged hexagonally. To design MCF, the relation among the crosstalk, fiber parameters, and fiber bend was derived using a new approximation model based on the coupled-mode theory with the equivalent index model. The mean values of the statistical distributions of the crosstalk were observed to be extremely low and estimated to be less than -30 dB even after 10,000-km propagation because of the trench-assisted cores and utilization of the fiber bend. The attenuation of each core was very low for MCFs (0.175--0.181 dB/km at 1550 nm) because of the pure-silica cores. Both the crosstalk and attenuation values are the lowest achieved in MCFs.

Hayashi, Tetsuya; Taru, Toshiki; Shimakawa, Osamu; Sasaki, Takashi; Sasaoka, Eisuke

2011-08-01

78

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

79

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

PubMed

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

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

2006-08-01

80

Design and fabrication of ultra-low crosstalk and low-loss multi-core fiber.  

PubMed

We designed and fabricated a multi-core fiber (MCF) in which seven identical trench-assisted pure-silica cores were arranged hexagonally. To design MCF, the relation among the crosstalk, fiber parameters, and fiber bend was derived using a new approximation model based on the coupled-mode theory with the equivalent index model. The mean values of the statistical distributions of the crosstalk were observed to be extremely low and estimated to be less than -30 dB even after 10,000-km propagation because of the trench-assisted cores and utilization of the fiber bend. The attenuation of each core was very low for MCFs (0.175-0.181 dB/km at 1550 nm) because of the pure-silica cores. Both the crosstalk and attenuation values are the lowest achieved in MCFs. PMID:21935022

Hayashi, Tetsuya; Taru, Toshiki; Shimakawa, Osamu; Sasaki, Takashi; Sasaoka, Eisuke

2011-08-15

81

McCARD for Neutronics Design and Analysis of Research Reactor Cores  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

82

Development and Design of the EPR™ Core Catcher  

Microsoft Academic Search

\\u000a The EPR™ is an evolutionary pressurized water reactor in the thermal range of 4,500 MWth, designed and marketed by AREVA NP.\\u000a Currently, there are four EPR™ plants under design and construction: Olkiluoto-3 (OL3) in Finland, Flamanville-3 (FA3) in\\u000a France, and Taishan 1&2 (TSN) in the People’s Republic of China.

Dietmar Bittermann; Manfred Fischer

83

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

2011-09-01

84

The convex hull of two core capacitated network design problems  

Microsoft Academic Search

The network loading problem (NLP) is a specialized capacitated network design problem in which prescribed point-to-point demand between various pairs of nodes of a network must be met by installing (loading) a capacitated facility. We can load any number of units of the facility on each of the arcs at a specified arc dependent cost. The problem is to determine

Thomas L. Magnanti; Prakash Mirchandani; Rita Vachani

1993-01-01

85

Reactor Physics Parameters of Alternate Fueled FBR Core Designs.  

National Technical Information Service (NTIS)

Nuclear non-proliferation considerations have resulted in renewed interest in the thorium fuel cycle. Reactor physics parameters of a typical 1200-MW(e) Fast Breeder Reactor (FBR) design were compared when U-233 is substituted for Pu as a fissile fuel and...

D. R. Haffner, R. W. Hardie

1977-01-01

86

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

87

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

PubMed

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

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

88

Determination of core design thermal safety limits for a two-loop pressurized water reactor  

SciTech Connect

Results are given of independent research of core thermal design limits for the Nuklearna Elektrarna Krsko (NEK) nuclear power plant; procedures for two-loop pressurized water reactor plant core design safety limit calculation are used. Emphasis is placed on researching the vessel exit boiling and the hot-channel exit quality limits and their impact on the maximum available design safety operating range and thermal operating margin of the NEK reactor core. For this purpose, the LIMITS computer code is developed. Based on the modified, well-tried COBRA-IV-I computer code, the departure of nuclear boiling ratio core safety limits are calculated. The original results complement well those of the NEK Final Safety Analysis Report. The procedures and the methods for determining the reactor core design thermal limits are successfully proven despite the unavailability of proprietary data, different models, and computer codes. In addition to the acquired capability of in-house independent checking of the vendor`s results, the bases are set for further independent analyses of the limiting safety system settings for the NEK core.

Kostadinov, V.

1996-04-01

89

Increasing sequence diversity with flexible backbone protein design: the complete redesign of a protein hydrophobic core.  

PubMed

Protein design tests our understanding of protein stability and structure. Successful design methods should allow the exploration of sequence space not found in nature. However, when redesigning naturally occurring protein structures, most fixed backbone design algorithms return amino acid sequences that share strong sequence identity with wild-type sequences, especially in the protein core. This behavior places a restriction on functional space that can be explored and is not consistent with observations from nature, where sequences of low identity have similar structures. Here, we allow backbone flexibility during design to mutate every position in the core (38 residues) of a four-helix bundle protein. Only small perturbations to the backbone, 1-2 Å, were needed to entirely mutate the core. The redesigned protein, DRNN, is exceptionally stable (melting point >140°C). An NMR and X-ray crystal structure show that the side chains and backbone were accurately modeled (all-atom RMSD = 1.3 Å). PMID:22632833

Murphy, Grant S; Mills, Jeffrey L; Miley, Michael J; Machius, Mischa; Szyperski, Thomas; Kuhlman, Brian

2012-06-01

90

Energy efficient engine. Core engine bearings, drives and configuration: Detailed design report  

NASA Technical Reports Server (NTRS)

The detailed design of the forward and aft sumps, the accessory drive system, the lubrication system, and the piping/manifold configuration to be employed in the core engine test of the Energy Efficient Engine is addressed. The design goals for the above components were established based on the requirements of the test cell engine.

Broman, C. L.

1981-01-01

91

Multi-frequency wrapper design and optimization for embedded cores under average power constraints  

Microsoft Academic Search

This paper presents a new method for designing test wrappers for embedded cores with multiple clock domains. By exploiting the use of multiple shift frequencies, the proposed method improves upon a recent wrapper design method that requires a common shift frequency for the scan elements in the different clock domains. We present an integer linear programming (ILP) model that can

Qiang Xu; Nicola Nicolici; Krishnendu Chakrabarty

2005-01-01

92

Design/Operations review of core sampling trucks and associated equipment  

SciTech Connect

A systematic review of the design and operations of the core sampling trucks was commissioned by Characterization Equipment Engineering of the Westinghouse Hanford Company in October 1995. The review team reviewed the design documents, specifications, operating procedure, training manuals and safety analysis reports. The review process, findings and corrective actions are summarized in this supporting document.

Shrivastava, H.P.

1996-03-11

93

Expanding the core: a new approach for the design of single-mode waveguides  

Microsoft Academic Search

A new approach is proposed for the design of single-mode waveguides. The approach is based on slicing the core of the waveguide into a uniform array of subwaveguides and expanding the separation between these waveguides up to the point where the array is still supporting a single supermode. By appropriate selection of the array design parameters, it is possible to

Tarek A. Ramadan

2005-01-01

94

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

95

Design and fabrication of the instrumented fuel elements for the Annular Core Research Reactor (ACRR)  

Microsoft Academic Search

This report describes the design and fabrication techniques for the instrumented fuel elements of the Annular Core Research Reactor (ACRR). The thermocouple assemblies were designed and fabricated at Sandia Laboratories while the instrumented elements were assembled at Los Alamos Scientific Laboratory. In order to satisfy the ACRR's Technical Specifications, the thermocouples are required to measure temperature in excess of 1800°C

T. R. Schmidt; D. J. Sasmor; J. T. Martin; F. Gonzalez; D. N. Cox

1981-01-01

96

Detailed Core Design and Flow Coolant Conditions for Neutron Flux Maximization in Research Reactors  

Microsoft Academic Search

Following the design of the German research reactor, FRM-II, which delivers high thermal neutron fluxes, we have already developed an asymmetric compact cylindrical core with an inner and outer reflector. The goal was to maximize the maximum thermal flux to power ratio, which is a desirable characteristic of a modern research reactor. This design, for a 10 MW power, was

F. E. Teruel; Rizwan Uddin

2006-01-01

97

Development of a thermal-hydraulic design methodology for an advanced reactor core with vertical parallel channels.  

National Technical Information Service (NTIS)

A thermal-hydraulic design methodology has been developed for the analysis of an advanced reactor core and compared the results with existing analysis data. On the basis of one dimensional core design methodology for the reference core, a computer code CO...

D. H. Hwang Y. J. Yoo K. K. Kim M. Chang

1998-01-01

98

Fuel and Core Design Verification for Extended Power Up-rate in Ringhals Unit 3  

SciTech Connect

Vattenfall's Westinghouse 3-loop PWR Ringhals 3 at the western coast of Sweden is scheduled for an extended power up-rate from 2783 to 3160 MWt in 2007, in the frame of the so called GREAT-project. The project will realize an up-rating initially planned and analysed back in 1995, but with a number of significant improvements outlined in this paper. For the licensing of the up-rated power level, a complete revision of the safety analyses, radiological analyses and systems verifications in FSAR is being performed by Westinghouse Electrics Belgium. The work is performed in close cooperation with Vattenfall in the areas of core calculations and input data. For more than a decade, Vattenfall has performed all core design and reload safety evaluations (RSE) for Ringhals, independent of fuel vendors and safety analysts. In GREAT all core parameters in the safety analysis checklist (SAC) used for the safety analyses are determined based upon a set of nine reference loading patterns designed by Vattenfall covering a wide range of fuel and core designs and extreme cycle-to-cycle variations. To facilitate the calculation of SAC parameters Westinghouse has provided a Reload Safety Evaluation Procedure report (RSEP) with detailed specifications for the calculation of all core parameters used in the analyses. The procedure has been automatized by Vattenfall in a set of scripts executing 3D core simulator calculations and extracting the key results. The same tools will be used in Vattenfall's future RSE for Ringhals 3. This approach is taken to obtain consistency between core designs and core calculations for the safety analyses and the cycle specific calculations, to minimize the risk for future violations of the safety analyses. (authors)

Gabrielsson, Petter; Stepniewski, Marek; Almberger, Jan [Vattenfall Bransle AB, Jaemtlandsg. 99, 162 87 Stockholm (Sweden)

2006-07-01

99

Design and VLSI implementation of a digital audio-specific DSP core for MP3\\/AAC  

Microsoft Academic Search

We present a digital audio-specific DSP core designed for a dual decoder for MPEG\\/audio layer-3 (MP3) and MPEG-2 advanced audio coding (AAC). The processing core is a 20-bit fixed-point programmable DSP having an architecture suitable for audio signal processing. It supports special instructions such as UNPACK and Huffman as well as general arithmetic and logical instructions including pipelined-MAC. All instructions

Kyoung Ho Bang; Nam Hun Jeong; Joon Seok Kim; Young Cheol Park; Dae Hee Youn

2002-01-01

100

Design and proposed utilization of the Sandia Annular Core Research Reactor (ACRR)  

Microsoft Academic Search

The Sandia ACRR became operational in 1978 and currently serves as the major in-pile fast reactor safety test facility for the US Nuclear Regulatory Commission. The ACRR is an upgrade of the Annular Core Pulse Reactor (ACPR) with the installation of a new flexible control system and a core of uniquely designed BeO-UO fuel elements for increasing the neutron fluence

J. V. Walker; J. A. Reuscher; P. S. Pickard

1979-01-01

101

Design and fabrication of a novel core-suspended optic fiber for distributed gas sensor  

NASA Astrophysics Data System (ADS)

we design a novel core-suspended capillary fiberhat the core is suspened in the air hole and close to the inner surface of the capillary, and experimentally demonstrate its fabrication technology. In addition, a method for linking a single mode fiber and a core-suspended fiber is proposed based on splicing and tapering at the fusion point between the two fibers. By combining with the optical time domain reflectometer technology, we construct a distributed gas sensor system to monitor greenhouse gas based on this novel fiber.

Zhang, T.; Ma, L. J.; Bai, H. B.; Tong, Ch. G.; Dai, Q.; Yang, J.; Yuan, L. B.

2013-09-01

102

Design and fabrication of a novel core-suspended optic fiber for distributed gas sensor  

NASA Astrophysics Data System (ADS)

We designed a novel core-suspended capillary fiber that the core was suspended in the air hole and close to the inner surface of the capillary, and experimentally demonstrated its fabrication technology. In addition, a method for linking a single mode fiber and a core-suspended fiber was proposed based on splicing and tapering at the fusion point between the two fibers. By combining with the optical time domain reflectometer technology, we constructed a distributed gas sensor system to monitor greenhouse gas based on this novel fiber.

Zhang, Tao; Ma, Lijia; Bai, Hongbo; Tong, Chengguo; Dai, Qiang; Kang, Chong; Yuan, Libo

2014-06-01

103

Effective Domain Partitioning for Multi-Clock Domain IP Core Wrapper Design under Power Constraints  

Microsoft Academic Search

The rapid advancement of VLSI technology has made it possible for chip designers and manufacturers to embed the components of a whole system onto a single chip, called System-on-Chip or SoC. SoCs make use of pre-designed modules, called IP-cores, which provide faster design time and quicker time-to-market. Furthermore, SoCs that operate at multiple clock domains and very low power requirements

Thomas Edison Yu; Tomokazu Yoneda; Danella Zhao; Hideo Fujiwara

2008-01-01

104

Digital Data Processing Peripheral Design for an Embedded Application based on the Microblaze Soft Core  

Microsoft Academic Search

In this paper we present a design of a peripheral for microblaze soft core processor as part of a R+D project carried out in cooperation with three different companies. The objective of the project consisted in the development of an embedded system with a SoC implemented on a FPGA custom-designed board. This work addresses the design of a digital data

E. Ostua; J. Viejo; M. J. Bellido; A. Millan; J. Juan; A. Munoz

2008-01-01

105

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

Microsoft Academic Search

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

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

2008-01-01

106

Design of air-gapped magnetic-core inductors for superimposed direct and alternating currents  

NASA Technical Reports Server (NTRS)

Using data on standard magnetic-material properties and standard core sizes for air-gap-type cores, an algorithm designed for a computer solution is developed which optimally determines the air-gap length and locates the quiescent point on the normal magnetization curve so as to yield an inductor design with the minimum number of turns for a given ac voltage and frequency and with a given dc bias current superimposed in the same winding. Magnetic-material data used in the design are the normal magnetization curve and a family of incremental permeability curves. A second procedure, which requires a simpler set of calculations, starts from an assigned quiescent point on the normal magnetization curve and first screens candidate core sizes for suitability, then determines the required turns and air-gap length.

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

1976-01-01

107

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

108

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

NASA Technical Reports Server (NTRS)

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

Hultgren, Lennart S.

2011-01-01

109

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

110

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

111

Validation of the Nuclear Design Method for MOX Fuel Loaded LWR Cores  

SciTech Connect

The actual batch loading of mixed-oxide (MOX) fuel in light water reactors (LWRs) is now ready to start in Japan. One of the efforts that have been devoted to realizing this batch loading has been validation of the nuclear design methods calculating the MOX-fuel-loaded LWR core characteristics. This paper summarizes the validation work for the applicability of the CASMO-4/SIMULATE-3 in-core fuel management code system to MOX-fuel-loaded LWR cores. This code system is widely used by a number of electric power companies for the core management of their commercial LWRs. The validation work was performed for both boiling water reactor (BWR) and pressurized water reactor (PWR) applications. Each validation consists of two parts: analyses of critical experiments and core tracking calculations of operating plants. For the critical experiments, we have chosen a series of experiments known as the VENUS International Program (VIP), which was performed at the SCK/CEN MOL laboratory in Belgium. VIP consists of both BWR and PWR fuel assembly configurations. As for the core tracking calculations, the operating data of MOX-fuel-loaded BWR and PWR cores in Europe have been utilized.

Saji, E.; Inoue, Y.; Mori, M.; Ushio, T.

2001-06-17

112

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

113

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

PubMed

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

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

2013-09-01

114

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

115

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

116

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

National Technical Information Service (NTIS)

This presentation is a summary of the core-noise implications of NASA's primary N+3 aircraft concepts. These concepts are the MIT/P'W D8.5 Double Bubble design, the Boeing/GE SUGAR Volt hybrid gas-turbine/electric engine concept, the NASA N3-X Turboelectr...

L. S. Hultgren

2011-01-01

117

Design and Analysis of a Claw Pole Permanent Magnet Motor With Molded Soft Magnetic Composite Core  

Microsoft Academic Search

Soft magnetic composite (SMC) materials and SMC electromagnetic devices have undergone substantial development in the past decade. Much work has been conducted on designing and prototyping various types of electrical machine. However, the iron cores were often made by cutting existing SMC preforms that were formed by compacting SMC powder in simple cylinder or bar-shape molds, and the magnetic properties

Youguang Guo; Jianguo Zhu; D. G. Dorrell

2009-01-01

118

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

119

Using Domain Partitioning in Wrapper Design for IP Cores Under Power Constraints  

Microsoft Academic Search

This paper presents a novel design method for power-aware test wrappers targeting embedded cores with multiple clock domains. We show that effective partitioning of clock domains combined with bandwidth conversion and gated-clocks would yield shorter test times due to greater flexibility when determining optimal test schedules especially under tight power constraints

Thomas Edison Yu; Tomokazu Yoneda; Danella Zhao; Hideo Fujiwara

2007-01-01

120

Design and test of a torsional vibratory core sampler for marine sediments  

Microsoft Academic Search

Studies of marine sediments for geological, biological or engineering purposes is an area of increasing importance as more investigations are directed toward surveys of submerged bottoms of oceans, lakes, and rivers. This paper summarizes a project initiated in Jan. 1969, to design, develop, and test prototype coring equipment for marine environments. The torsional system of vibration offers several specific advantages

R. J. Harker; R. M. Shah

1971-01-01

121

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

Microsoft Academic Search

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

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

2001-01-01

122

Estimation of hot spot temperature in distribution transformer considering core design using FEM  

Microsoft Academic Search

Power transformers represent the largest portion of capital investment in transmission and distribution substations. One of the most important parameters governing a transformerpsilas life expectancy is the hot-spot temperature. Therefore design of transformer is so important that should be considered. Core is one of parts of transformer that is effective on hot-spot temperature. This paper presents a methodology to assess

Sh. Taheri; A. Vahedi; A. Gholami; H. Taheri

2008-01-01

123

Development of design options for the port plug components of the ITER core CXRS diagnostic  

Microsoft Academic Search

The paper presents component concepts developed for the ITER core charge exchange recombination spectroscopy (cCXRS). They are based on the cCXRS layout of 2009, named as reference design option. It includes an outer shell, carrying a blanket shield module and a shielding cassette. The cassette, attached to the outer shell, carries secondary mirrors and a retractable tube. The tube holds

Yu. Krasikov; T. Baross; W. Biel; A. Litnovsky; N. Hawkes; G. Kiss; J. F. F. Klinkhamer; J. F. Koning; A. Krimmer; O. Neubauer; A. Panin

2011-01-01

124

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

National Technical Information Service (NTIS)

A new non-TRISO fuel and clad design concept is proposed for the prismatic, helium cooled Very High Temperature Reactor core. The new concept could substantially reduce the current 10-20 wt% TRISO uranium enrichments down to 4-6 wt% for both initial and r...

J. W. Sterbentz

2007-01-01

125

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

Microsoft Academic Search

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

1995-01-01

126

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

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

127

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

Microsoft Academic Search

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

Nupur Lodha; Nivesh Rai; Rahul Dubey; Hrishikesh Venkataraman

2009-01-01

128

Effectiveness of Horizontal Stirrups in Joint Core for Exterior Beam-Column Joints with Nonseismic Design  

Microsoft Academic Search

Reversed cyclic-load tests on full-scale reinforced concrete exterior beam-column joints with nonseismic design to the British standard BS 8110 were carried out. The seismic behaviour of these non-seismically designed beamcolumn joints was investigated, and the effectiveness of horizontal stirrups in joint core on the seismic performance and shear strength of the joints were emphasised. It was found that horizontal stirrups

J. S. Kaung; H. F. Wong

2011-01-01

129

Design and analysis of a nuclear reactor core for innovative small light water reactors  

NASA Astrophysics Data System (ADS)

In order to address the energy needs of developing countries and remote communities, Oregon State University has proposed the Multi-Application Small Light Water Reactor (MASLWR) design. In order to achieve five years of operation without refueling, use of 8% enriched fuel is necessary. This dissertation is focused on core design issues related with increased fuel enrichment (8.0%) and specific MASLWR operational conditions (such as lower operational pressure and temperature, and increased leakage due to small core). Neutron physics calculations are performed with the commercial nuclear industry tools CASMO-4 and SIMULATE-3, developed by Studsvik Scandpower Inc. The first set of results are generated from infinite lattice level calculations with CASMO-4, and focus on evaluation of the principal differences between standard PWR fuel and MASLWR fuel. Chapter 4-1 covers aspects of fuel isotopic composition changes with burnup, evaluation of kinetic parameters and reactivity coefficients. Chapter 4-2 discusses gadolinium self-shielding and shadowing effects, and subsequent impacts on power generation peaking and Reactor Control System shadowing. The second aspect of the research is dedicated to core design issues, such as reflector design (chapter 4-3), burnable absorber distribution and programmed fuel burnup and fuel use strategy (chapter 4-4). This section also includes discussion of the parameters important for safety and evaluation of Reactor Control System options for the proposed core design. An evaluation of the sensitivity of the proposed design to uncertainty in calculated parameters is presented in chapter 4-5. The results presented in this dissertation cover a new area of reactor design and operational parameters, and may be applicable to other small and large pressurized water reactor designs.

Soldatov, Alexey I.

130

The SNL100-02 blade : advanced core material design studies for the Sandia 100-meter blade.  

SciTech Connect

A series of design studies are performed to investigate the effects of advanced core materials and a new core material strategy on blade weight and performance for large blades using the Sandia 100-meter blade designs as a starting point. The initial core material design studies were based on the SNL100-01 100- meter carbon spar design. Advanced core material with improved performance to weight was investigated with the goal to reduce core material content in the design and reduce blade weight. A secondary element of the core study was to evaluate the suitability of core materials from natural, regrowable sources such as balsa and recyclable foam materials. The new core strategy for the SNL100-02 design resulted in a design mass of 59 tons, which is a 20% reduction from the most recent SNL100-01 carbon spar design and over 48% reduction from the initial SNL100-00 all-glass baseline blade. This document provides a description of the final SNL100-02 design, includes a description of the major design modifications, and summarizes the pertinent blade design information. This document is also intended to be a companion document to the distribution of the NuMAD blade model files for SNL100-02 that are made publicly available.

Griffith, Daniel Todd

2013-11-01

131

Fuel cycles and advanced core designs for the gas cooled fast-breeder reactor  

SciTech Connect

This report summarizes the fuel cycle and advanced core design analysis for the gas-cooled fast breeder reactor (GCFR) performed in conjunction with the Nonproliferation Alternative Systems Assessment Program (NASAP) and the International Nuclear Fuel Cycle Evaluation (INFCE) between 1976 and 1980. The report contrasts traditional fast reactor fuel cycles (plutonium/uranium) with alternative (uranium/thorium) cycles in an effort to define fuel systems which might reduce nuclear weapons proliferation risks without incurring extreme resource or economic disadvantages. It studies symbiotic reactor systems involving fast and thermal reactors and provides basic GCFR mass flow information for NASAP and INFCE. It defines an improved fuel cycle performance index (i.e., energy potential) for reactors and reactor systems. This improved index is combined with sensitivity studies of core materials and configurations to select the basic core and primary system characteristics for future core designs. This report establishes and characterizes advanced designs which may represent targets for future commercial-size fast reactors.

Hamilton, C.J.; Perkins, R.G.

1982-07-01

132

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

NASA Astrophysics Data System (ADS)

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

Qvist, Staffan Alexander

133

A particle-bed gas cooled fast reactor core design for waste minimization.  

SciTech Connect

The issue of waste minimization in advanced reactor systems has been investigated using the Particle-Bed Gas-Cooled Fast Reactor (PB-GCFR) design being developed and funded under the U.S. Department of Energy Nuclear Energy Research Initiative (USDOE NERI) Program. Results indicate that for the given core power density and constraint on the maximum TRU enrichment allowable, the lowest amount of radiotoxic transuranics to be processed and hence sent to the repository is obtained for long-life core designs. Calculations were additionally done to investigate long-life core designs using LWR spent fuel TRU and recycle TRU, and different feed, matrix and reflector materials. The recycled TRU and LWR spent TRU fuels give similar core behaviors, because of the fast spectrum environment which does not significantly degrade the TRU composition. Using light elements as reflector material was found to be unattractive because of power peaking problems and large reactivity swings. The application of a lead reflector gave the longest cycle length and lowest TRU processing requirement. Materials compatibility and performance issues require additional investigation.

Hoffman, E. A.; Taiwo, T. A.; Yang, W. S.; Fatone, M.

2002-10-11

134

Design and fabrication of the instrumented fuel elements for the Annular Core Research Reactor (ACRR)  

SciTech Connect

This report describes the design and fabrication techniques for the instrumented fuel elements of the Annular Core Research Reactor (ACRR). The thermocouple assemblies were designed and fabricated at Sandia Laboratories while the instrumented elements were assembled at Los Alamos Scientific Laboratory. In order to satisfy the ACRR's Technical Specifications, the thermocouples are required to measure temperature in excess of 1800/sup 0/C under rapid heating conditions. Because of the potentially high failure rates for thermocouples in such environments, the instrumented fuel elements are designed so that the thermocouples can be replaced easily.

Schmidt, T.R.; Sasmor, D.J.; Martin, J.T.; Gonzalez, F.; Cox, D.N.

1981-04-01

135

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

136

An approach for catalyst design in artificial photosynthetic systems: focus on nanosized inorganic cores within proteins.  

PubMed

Some enzymes can be considered as a catalyst having a nanosized inorganic core in a protein matrix. In some cases, the metal oxide or sulfide clusters, which can be considered as cofactors in enzymes, may be recruited for use in other related reactions in artificial photosynthetic systems. In other words, one approach to design efficient and environmentally friendly catalysts in artificial photosynthetic systems for the purpose of utilizing sunlight to generate high energy intermediates or useful material is to select and utilize inorganic cores of enzymes. For example, one of the most important goals in developing artificial photosynthesis is hydrogen production. However, first, it is necessary to find a "super catalyst" for water oxidation, which is the most challenging half reaction of water splitting. There is an efficient system for water oxidation in cyanobacteria, algae, and plants. Published data on the Mn-Ca cluster have provided details on the mechanism and structure of the water oxidizing complex as a Mn-Ca nanosized inorganic core in photosystem II. Progress has been made in introducing Mn-Ca oxides as efficient catalysts for water oxidation in artificial photosynthetic systems. Here, in the interest of designing efficient catalysts for other important reactions in artificial photosynthesis, a few examples of our knowledge of inorganic cores of proteins, and how Nature used them for important reactions, are discussed. PMID:23377954

Najafpour, Mohammad Mahdi

2013-11-01

137

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

138

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

139

Optimum design of imploded core plasma for effective fast ignition at GXII  

NASA Astrophysics Data System (ADS)

In the implosion phase of the fast ignition scheme, most critical issues are breakup of the cone tip and the formation of high ?-R core plasma to improve its heating efficiency. For the integrated fast ignition experiment at ILE Osaka University, robust and reliable implosion must be redesign. In this paper, feasible target design under the constraint condition of existing GXII and LFEX facilities is studied using two-dimensional radiation hydrodynamic simulations, and an optimum target design based on low velocity implosion is proposed. The advantages of low velocity implosion are low adiabat, robust against Rayleigh-Taylor instability, which are verified. Also longer life time of compressed core plasma which is preferable for fast ignition is confirmed in this study.

Nagatomo, H.; Johzaki, T.; Sunahara, A.; Sakagami, H.; Yanagawa, T.; Mima, K.

2013-11-01

140

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

141

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

NASA Technical Reports Server (NTRS)

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

Stearns, E. Marshall

1985-01-01

142

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

143

Analytical Results for Design Space Exploration of Many-Core Processors for Sound Synthesis of Guitar  

Microsoft Academic Search

In this paper, we present a design space exploration of optimal many-core processors for the physics-based sound synthesis of guitar by quantitatively evaluating the impact of a sample-per-processing element (SPE) ratio - the amount of sample data directly mapped to each processing element (or varying the number of processing elements for a fixed sample size) on system performance and efficiency

Myeongsu Kang; Jiwon Choi; Jong-Myon Kim

2011-01-01

144

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

145

Dual optical tweezers integrated in a four-core fiber: design and simulation  

NASA Astrophysics Data System (ADS)

We propose a novel dual optical fiber tweezers integrated in a four-core fiber which can trap, rotate and orient a micro particle immersed in a fluid medium. We design the structures and the functions of this dual optical fiber tweezers, and simulate the optical trapping forces, optical torques exerting on the micro particle. We also give out the experimental setup and the controlling method of this integrated dual optical fiber tweezers.

Zhang, Yu; Yuan, Libo; Liu, Zhihai; Yang, Jun

2013-09-01

146

Integrating IMS Learning Design and IMS Question and Test Interoperability using CopperCore Service Integration  

Microsoft Academic Search

Please, cite this publication as: Vogten, H., Martens, H., Nadolski, R., Tattersall, C., van Rosmalen, P., & Koper, R. (2006). Integrating IMS Learning Design and IMS Question and Test Interoperability using CopperCore Service Integration. Proceedings of International Workshop in Learning Networks for Lifelong Competence Development, TENCompetence Conference. March 30th-31st, Sofia, Bulgaria: TENCompetence. Retrieved June 30th, 2006, from http:\\/\\/dspace.learningnetworks.org

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

2006-01-01

147

Lunar in-core thermionic nuclear reactor power system conceptual design  

NASA Technical Reports Server (NTRS)

This paper presents a conceptual design of a lunar in-core thermionic reactor power system. The concept consists of a thermionic reactor located in a lunar excavation with surface mounted waste heat radiators. The system was integrated with a proposed lunar base concept representative of recent NASA Space Exploration Initiative studies. The reference mission is a permanently-inhabited lunar base requiring a 550 kWe, 7 year life central power station. Performance parameters and assumptions were based on the Thermionic Fuel Element (TFE) Verification Program. Five design cases were analyzed ranging from conservative to advanced. The cases were selected to provide sensitivity effects on the achievement of TFE program goals.

Mason, Lee S.; Schmitz, Paul C.; Gallup, Donald R.

1991-01-01

148

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

NASA Astrophysics Data System (ADS)

A dry-type pulse transformer based on Fe-based nanocrystalline core with a load of 0.88 nF, output voltage of more than 65 kV, and winding ratio of 46 is designed and constructed. The dynamic characteristics of Fe-based nanocrystalline core under the impulse with the pulse width of several microseconds were studied. The pulse width and incremental flux density have an important effect on the pulse permeability, so the pulse permeability is measured under a certain pulse width and incremental flux density. The minimal volume of the toroidal pulse transformer core is determined by the coupling coefficient, the capacitors of the resonant charging circuit, incremental flux density, and pulse permeability. The factors of the charging time, ratio, and energy transmission efficiency in the resonant charging circuit based on magnetic core-type pulse transformer are analyzed. Experimental results of the pulse transformer are in good agreement with the theoretical calculation. When the primary capacitor is 3.17 ?F and charge voltage is 1.8 kV, a voltage across the secondary capacitor of 0.88 nF with peak value of 68.5 kV, rise time (10%-90%) of 1.80 ?s is obtained.

Yi, Liu; Xibo, Feng; Lin, Fuchang

2011-08-01

149

Design and operation of the core topography data acquisition system for TMI-2  

SciTech Connect

Development of effective procedures for recovery from the 1979 accident at the Three Mile Island 2 nuclear station requires a detailed and quantitative description of the postaccident configuration of the core. This report describes the techniques, equipment, and procedures used for making precise ultrasonic, sonar-like measurements of the cavity left in the upper core region as a result of the accident and details the primary results of the measurements. The system developed for the measurements uses computer techniques for the command and control of remote mechanical and electronic equipment, and for data acquisition and reduction. The system was designed, fabricated, and tested; procedures developed; and personnel trained in 4-1/2 months. The primary results are detailed topographic maps of the cavity. A variety of visual aids was developed to supplement the maps and aid in interpreting companion videotape surveys. The measurements reveal a cavity of 9.3 m/sup 3/, approximately 26% of the total core volume. The cavity occupies most of the full diameter of the core to an average depth of about 1.5 m and approaches 2 m in places.

Beller, L.S.; Brown, H.L.

1984-05-01

150

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

PubMed

A dry-type pulse transformer based on Fe-based nanocrystalline core with a load of 0.88 nF, output voltage of more than 65 kV, and winding ratio of 46 is designed and constructed. The dynamic characteristics of Fe-based nanocrystalline core under the impulse with the pulse width of several microseconds were studied. The pulse width and incremental flux density have an important effect on the pulse permeability, so the pulse permeability is measured under a certain pulse width and incremental flux density. The minimal volume of the toroidal pulse transformer core is determined by the coupling coefficient, the capacitors of the resonant charging circuit, incremental flux density, and pulse permeability. The factors of the charging time, ratio, and energy transmission efficiency in the resonant charging circuit based on magnetic core-type pulse transformer are analyzed. Experimental results of the pulse transformer are in good agreement with the theoretical calculation. When the primary capacitor is 3.17 ?F and charge voltage is 1.8 kV, a voltage across the secondary capacitor of 0.88 nF with peak value of 68.5 kV, rise time (10%-90%) of 1.80 ?s is obtained. PMID:21895262

Yi, Liu; Xibo, Feng; Lin, Fuchang

2011-08-01

151

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

SciTech Connect

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

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

2009-07-15

152

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

SciTech Connect

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

Sterbentz, James W

2007-05-01

153

Core design study on rock-like oxide fuel light water reactor and improvements of core characteristics  

NASA Astrophysics Data System (ADS)

A rock-like oxide (ROX) fuel - LWR burning system has been studied for efficient plutonium transmutation. A zirconia based ROX (Zr-ROX) core has problems such as a small negative Doppler coefficient and a large power peaking factor, which causes severe transients in accidents and high fuel temperature even under nominal condition. For the improvement of these characteristics, two approaches were considered: the additives UO 2, ThO 2 and Er 2O 3, or a heterogeneous core with Zr-ROX and UO 2 assemblies. As a result, the combination of the additives UO 2 and Er 2O 3 is found to sufficiently improve the accident behavior, while a further power peaking reduction may be necessary for the Zr-ROX + UO 2 heterogeneous core. The plutonium transmutation rate is extremely high in Zr-ROX assemblies in the heterogeneous core, to be more than 85% and 70%, respectively for weapons- and reactor-grade plutonium. The plutonium transmutation rate becomes smaller in the full-ROX core with the UO 2 or ThO 2 additive, but the annual transmutation amount of plutonium is large, in comparison with the full-MOX fuel core.

Akie, H.; Takano, H.; Anoda, Y.

1999-08-01

154

Realistic Design of Large-Hollow-Core Photonic BandGap Fibers With Suppressed Higher Order Modes and Surface Modes  

Microsoft Academic Search

This paper theoretically describes effective suppression of higher order modes (HOMs) in realistic large-hollow-core photonic band-gap fibers (PBGFs) and utilizes the use of this class of waveguides for low-loss data-transmission applications and high-power beam delivery systems. The proposed design strategy is based on the resonant-coupling mechanism of central air-core modes with defected outer core modes. By incorporating six 7-unit-cell air

Kunimasa Saitoh; Nikolaos John Florous; Tadashi Murao; Masanori Koshiba

2007-01-01

155

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

SciTech Connect

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

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

1997-04-01

156

Design of a Vector-Vorticity Dynamical Core on a Hexagonal Grid (Hex-VVDC)  

NASA Astrophysics Data System (ADS)

We are developing a Global Cloud-Resolving Model (GCRM) based on the vector-vorticity dynamical core (VVDC) that predicts three-dimensional vorticity. The VVDC in an anelastic framework has been originally designed by Jung and Arakawa and used in a Cartesian grid. As the first step in developing the GCRM, we have constructed an intermediate model with the VVDC using a hexagonal grid on a planar quasi-rectangular horizontal domain, which we call the hexagonal VVDC (Hex-VVDC). The purpose of developing the Hex-VVDC is to test and verify the discretization of equations of the VVDC on a hexagonal grid before applying them to the geodesic hexagon/pentagon grid that will be used for the GCRM. It is found that having twice as many as cell walls and three times as many as cell corners than the cell centers in a hexagonal grid produces a computational mode in horizontal and vertical components of vorticity and horizontal velocity fields, which the dynamics cannot control. We have designed a special scheme to treat this computational mode. With this treatment, the Hex-VVDC seems to work well. Currently, we are performing further tests with the Hex-VVDC and also continuing the application of the dynamical core to the geodesic hexagon/pentagon grid. In this presentation, we will discuss the computational design of the Hex-VVDC and show simulated results primarily focusing on vertical transports of vorticity and momentum by convection.

Konor, C. S.; Heikes, R. P.; Jung, J.; Randall, D.; Arakawa, A.

2009-05-01

157

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

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

158

Efficient Design and Analysis of Lightweight Reinforced Core Sandwich and PRSEUS Structures  

NASA Technical Reports Server (NTRS)

Design, analysis, and sizing methods for two novel structural panel concepts have been developed and incorporated into the HyperSizer Structural Sizing Software. Reinforced Core Sandwich (RCS) panels consist of a foam core with reinforcing composite webs connecting composite facesheets. Boeing s Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) panels use a pultruded unidirectional composite rod to provide axial stiffness along with integrated transverse frames and stitching. Both of these structural concepts are ovencured and have shown great promise applications in lightweight structures, but have suffered from the lack of efficient sizing capabilities similar to those that exist for honeycomb sandwich, foam sandwich, hat stiffened, and other, more traditional concepts. Now, with accurate design methods for RCS and PRSEUS panels available in HyperSizer, these concepts can be traded and used in designs as is done with the more traditional structural concepts. The methods developed to enable sizing of RCS and PRSEUS are outlined, as are results showing the validity and utility of the methods. Applications include several large NASA heavy lift launch vehicle structures.

Bednarcyk, Brett A.; Yarrington, Phillip W.; Lucking, Ryan C.; Collier, Craig S.; Ainsworth, James J.; Toubia, Elias A.

2012-01-01

159

An intrinsically safe facility for forefront research and training on nuclear technologies — Core design  

NASA Astrophysics Data System (ADS)

The core of a subcritical, low-power research reactor in a lead matrix has been designed using the MCNPX code. The main parameters, like geometry, material composition in the fuel assembly and reflector size, have been optimized for a k eff ˜ 0.95 and a thermal power around 200 Kw. A 70 Mev, 1 mA proton beam incident on a beryllium target has been assumed as neutron source and the corresponding thermal power distribution and neutron fluxes in the reactor have been simulated.

Viberti, C. M.; Ricco, G.

2014-04-01

160

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

161

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

162

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

163

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

Microsoft Academic Search

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

Antonino Romano; Neil E. Todreas

2002-01-01

164

Common Core State Standards for Mathematics. Appendix A: Designing High School Mathematics Courses Based on the Common Core State Standards  

ERIC Educational Resources Information Center

The Common Core State Standards (CCSS) for Mathematics are organized by grade level in Grades K-8. At the high school level, the standards are organized by conceptual category (number and quantity, algebra, functions, geometry, modeling and probability and statistics), showing the body of knowledge students should learn in each category to be…

Common Core State Standards Initiative, 2011

2011-01-01

165

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

166

Small Launch Vehicle Design Approaches: Clustered Cores Compared with Multi-Stage Inline Concepts  

NASA Technical Reports Server (NTRS)

In an effort to better define small launch vehicle design options two approaches were investigated from the small launch vehicle trade space. The primary focus was to evaluate a clustered common core design against a purpose built inline vehicle. Both designs focused on liquid oxygen (LOX) and rocket propellant grade kerosene (RP-1) stages with the terminal stage later evaluated as a LOX/methane (CH4) stage. A series of performance optimization runs were done in order to minimize gross liftoff weight (GLOW) including alternative thrust levels, delivery altitude for payload, vehicle length to diameter ratio, alternative engine feed systems, re-evaluation of mass growth allowances, passive versus active guidance systems, and rail and tower launch methods. Additionally manufacturability, cost, and operations also play a large role in the benefits and detriments for each design. Presented here is the Advanced Concepts Office's Earth to Orbit Launch Team methodology and high level discussion of the performance trades and trends of both small launch vehicle solutions along with design philosophies that shaped both concepts. Without putting forth a decree stating one approach is better than the other; this discussion is meant to educate the community at large and let the reader determine which architecture is truly the most economical; since each path has such a unique set of limitations and potential payoffs.

Waters, Eric D.; Beers, Benjamin; Esther, Elizabeth; Philips, Alan; Threet, Grady E., Jr.

2013-01-01

167

Development of Optimized Core Design and Analysis Methods for High Power Density BWRs  

NASA Astrophysics Data System (ADS)

Increasing the economic competitiveness of nuclear energy is vital to its future. Improving the economics of BWRs is the main goal of this work, focusing on designing cores with higher power density, to reduce the BWR capital cost. Generally, the core power density in BWRs is limited by the thermal Critical Power of its assemblies, below which heat removal can be accomplished with low fuel and cladding temperatures. The present study investigates both increases in the heat transfer area between ~he fuel and coolant and changes in operating parameters to achieve higher power levels while meeting the appropriate thermal as well as materials and neutronic constraints. A scoping study is conducted under the constraints of using fuel with cylindrical geometry, traditional materials and enrichments below 5% to enhance its licensability. The reactor vessel diameter is limited to the largest proposed thus far. The BWR with High power Density (BWR-HD) is found to have a power level of 5000 MWth, equivalent to 26% uprated ABWR, resulting into 20% cheaper O&M and Capital costs. This is achieved by utilizing the same number of assemblies, but with wider 16x16 assemblies and 50% shorter active fuel than that of the ABWR. The fuel rod diameter and pitch are reduced to just over 45% of the ABWR values. Traditional cruciform form control rods are used, which restricts the assembly span to less than 1.2 times the current GE14 design due to limitation on shutdown margin. Thus, it is possible to increase the power density and specific power by 65%, while maintaining the nominal ABWR Minimum Critical Power Ratio (MCPR) margin. The plant systems outside the vessel are assumed to be the same as the ABWR-Il design, utilizing a combination of active and passive safety systems. Safety analyses applied a void reactivity coefficient calculated by SIMULA TE-3 for an equilibrium cycle core that showed a 15% less negative coefficient for the BWR-HD compared to the ABWR. The feedwater temperature was kept the same for the BWR-HD and ABWR which resulted in 4 °K cooler core inlet temperature for the BWR-HD given that its feedwater makes up a larger fraction of total core flow. The stability analysis using the STAB and S3K codes showed satisfactory results for the hot channel, coupled regional out-of-phase and coupled core-wide in-phase modes. A RELAPS model of the ABWR system was constructed and applied to six transients for the BWR-HD and ABWR. The 6MCPRs during all the transients were found to be equal or less for the new design and the core remained covered for both. The lower void coefficient along with smaller core volume proved to be advantages for the simulated transients. Helical Cruciform Fuel (HCF) rods were proposed in prior MIT studies to enhance the fuel surface to volume ratio. In this work, higher fidelity models (e.g. CFD instead of subchannel methods for the hydraulic behaviour) are used to investigate the resolution needed for accurate assessment of the HCF design. For neutronics, conserving the fuel area of cylindrical rods results in a different reactivity level with a lower void coefficient for the HCF design. In single-phase flow, for which experimental results existed, the friction factor is found to be sensitive to HCF geometry and cannot be calculated using current empirical models. A new approach for analysis of flow crisis conditions for HCF rods in the context of Departure from Nucleate Boiling (DNB) and dryout using the two phase interface tracking method was proposed and initial results are presented. It is shown that the twist of the HCF rods promotes detachment of a vapour bubble along the elbows which indicates no possibility for an early DNB for the HCF rods and in fact a potential for a higher DNB heat flux. Under annular flow conditions, it was found that the twist suppressed the liquid film thickness on the HCF rods, at the locations of the highest heat flux, which increases the possibility of reaching early dryout. It was also shown that modeling the 3D heat and stress distribution in the HCF rods is necessary

Shirvan, Koroush

168

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

169

The IPE Database: providing information on plant design, core damage frequency and containment performance  

SciTech Connect

A database, called the IPE Database has been developed that stores data obtained from the Individual Plant Examinations (IPEs) which licensees of nuclear power plants have conducted in response to the Nuclear Regulatory Commission`s (NRC) Generic Letter GL88-20. The IPE Database is a collection of linked files which store information about plant design, core damage frequency (CDF), and containment performance in a uniform, structured way. The information contained in the various files is based on data contained in the IPE submittals. The information extracted from the submittals and entered into the IPE Database can be manipulated so that queries regarding individual or groups of plants can be answered using the IPE Database.

Lehner, J.R.; Lin, C.C.; Pratt, W.T. [Brookhaven National Lab., Upton, NY (United States); Su, T.; Danziger, L. [U.S. Nuclear Regulartory Commission, No. Bethesda, MD (United States)

1996-08-01

170

Parameter Design and Optimal Control of an Open Core Flywheel Energy Storage System  

NASA Technical Reports Server (NTRS)

In low earth orbit (LEO) satellite applications spacecraft power is provided by photovoltaic cells and batteries. To overcome battery shortcomings the University of Maryland, working in cooperation with NASA/GSFC and NASA/LeRC, has developed a magnetically suspended flywheel for energy storage applications. The system is referred to as an Open Core Composite Flywheel (OCCF) energy storage system. Successful application of flywheel energy storage requires integration of several technologies, viz. bearings, rotor design, motor/generator, power conditioning, and system control. In this paper we present a parameter design method which has been developed for analyzing the linear SISO model of the magnetic bearing controller for the OCCF. The objective of this continued research is to principally analyze the magnetic bearing system for nonlinear effects in order to increase the region of stability, as determined by high speed and large air gap control. This is achieved by four tasks: (1) physical modeling, design, prototyping, and testing of an improved magnetically suspended flywheel energy storage system, (2) identification of problems that limit performance and their corresponding solutions, (3) development of a design methodology for magnetic bearings, and (4) design of an optimal controller for future high speed applications. Both nonlinear SISO and MIMO models of the magnetic system were built to study limit cycle oscillations and power amplifier saturation phenomenon observed in experiments. The nonlinear models include the inductance of EM coils, the power amplifier saturation, and the physical limitation of the flywheel movement as discussed earlier. The control program EASY5 is used to study the nonlinear SISO and MIMO models. Our results have shown that the characteristics and frequency responses of the magnetic bearing system obtained from modeling are comparable to those obtained experimentally. Although magnetic saturation is shown in the bearings, there are good correlations between the theoretical model and experimental data. Both simulation and experiment confirm large variations of the magnetic bearing characteristics due to air gap growth. Therefore, the gap growth effect should be considered in the magnetic bearing system design. Additionally, the magnetic bearing control system will be compared to other design methods using not only parameter design but H-infinity optimal control and mu synthesis.

Pang, D.; Anand, D. K.; Kirk, J. A.

1996-01-01

171

Optimization of the core configuration design using a hybrid artificial intelligence algorithm for research reactors  

Microsoft Academic Search

To successfully carry out material irradiation experiments and radioisotope productions, a high thermal neutron flux at irradiation box over a desired life time of a core configuration is needed. On the other hand, reactor safety and operational constraints must be preserved during core configuration selection. Two main objectives and two safety and operational constraints are suggested to optimize reactor core

Afshin Hedayat; Hadi Davilu; Ahmad Abdollahzadeh Barfrosh; Kamran Sepanloo

2009-01-01

172

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

173

Design of efficient Java message-passing collectives on multi-core clusters  

Microsoft Academic Search

This paper presents a scalable and efficient Message-Passing in Java (MPJ) collective communication library for parallel computing\\u000a on multi-core architectures. The continuous increase in the number of cores per processor underscores the need for scalable\\u000a parallel solutions. Moreover, current system deployments are usually multi-core clusters, a hybrid shared\\/distributed memory\\u000a architecture which increases the complexity of communication protocols. Here, Java represents

Guillermo L. Taboada; Sabela Ramos; Juan Touriño; Ramon Doallo

2011-01-01

174

Novel Inhibitor Design for Hemagglutinin against H1N1 Influenza Virus by Core Hopping Method  

PubMed Central

The worldwide spread of H1N1 avian influenza and the increasing reports about its resistance to the current drugs have made a high priority for developing new anti-influenza drugs. Owing to its unique function in assisting viruses to bind the cellular surface, a key step for them to subsequently penetrate into the infected cell, hemagglutinin (HA) has become one of the main targets for drug design against influenza virus. To develop potent HA inhibitors, the ZINC fragment database was searched for finding the optimal compound with the core hopping technique. As a result, the Neo6 compound was obtained. It has been shown through the subsequent molecular docking studies and molecular dynamic simulations that Neo6 not only assumes more favorable conformation at the binding pocket of HA but also has stronger binding interaction with its receptor. Accordingly, Neo6 may become a promising candidate for developing new and more powerful drugs for treating influenza. Or at the very least, the findings reported here may provide useful insights to stimulate new strategy in this area.

Li, Xiao-Bo; Wang, Shu-Qing; Xu, Wei-Ren; Wang, Run-Ling; Chou, Kuo-Chen

2011-01-01

175

Alternative Design Concepts for the ITER Core Ion-Temperature Diagnostics  

NASA Astrophysics Data System (ADS)

Measurements of the ion temperature and plasma flow velocities in the ITER core must be made with spatial and temporal resolutions of 10 cm and 10 ms, respectively, over the range r/a=0-0.85. These requirements can be met by Doppler measurements of the spectral lines of neon- or helium-like, ion of tungsten, iron, and krypton with high-resolution x-ray imaging crystal spectrometers consisting of one spherically bent crystal and an array of two-dimensional pixilated detectors in a Johann configuration. One detector dimension displays spectral information and the other displays spatial information in a direction perpendicular to the toroidal magnetic field. It is challenging to implement this type of spectrometer on ITER due to neutron and gamma streaming through the viewing apertures. This paper discusses the feasibility of two alternative design concepts: a spectrometer with two concentric, spherically bent (convex and concave) crystals and a new von Hamos type spectrometer with one spherically bent (concave) crystal.

Bitter, Manfred; Delgado-Aparicio, Luis; Efthimion, Philip; Feder, Russell; Hill, Kenneth; Johnson, David; Pablant, Novimir; Stratton, Brent; Young, Kenneth; Beiersdorfer, Peter; Wang, Eric; Barnsley, Robin

2012-10-01

176

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

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

177

Core and plant design of the power reactor cooled and moderated by supercritical light water with single tube water rods  

Microsoft Academic Search

A reactor cooled and moderated by supercritical light water with single tube water rods is designed. The plant system is a once-through direct cycle; the whole coolant which flows once through the core is fed to the turbine. This reactor is much simpler than the current light water reactors LWRs, which enhances its economy. The average outlet coolant temperature should

K. Dobashi; Y. Oka; S. Koshizuka

1997-01-01

178

Design and Performance Improvements of the Prototype Open Core Flywheel Energy Storage System  

NASA Technical Reports Server (NTRS)

A prototype magnetically suspended composite flywheel energy storage (FES) system is operating at the University of Maryland. This system, designed for spacecraft applications, incorporates recent advances in the technologies of composite materials, magnetic suspension, and permanent magnet brushless motor/generator. The current system is referred to as an Open Core Composite Flywheel (OCCF) energy storage system. This paper will present design improvements for enhanced and robust performance. Initially, when the OCCF prototype was spun above its first critical frequency of 4,500 RPM, the rotor movement would exceed the space available in the magnetic suspension gap and touchdown on the backup mechanical bearings would occur. On some occasions it was observed that, after touchdown, the rotor was unable to re-suspend as the speed decreased. Additionally, it was observed that the rotor would exhibit unstable oscillations when the control system was initially turned on. Our analysis suggested that the following problems existed: (1) The linear operating range of the magnetic bearings was limited due to electrical and magnetic saturation; (2) The inductance of the magnetic bearings was affecting the transient response of the system; (3) The flywheel was confined to a small movement because mechanical components could not be held to a tight tolerance; and (4) The location of the touchdown bearing magnifies the motion at the pole faces of the magnetic bearings when the linear range is crucial. In order to correct these problems an improved design of the flywheel energy storage system was undertaken. The magnetic bearings were re-designed to achieve a large linear operating range and to withstand load disturbances of at least 1 g. The external position transducers were replaced by a unique design which were resistant to magnetic field noise and allowed cancellation of the radial growth of the flywheel at high speeds. A central rod was utilized to ensure the concentricity of the magnetic bearings, the motor/generator, and the mechanical touchdown bearings. In addition, the mechanical touchdown bearings were placed at two ends of the magnetic bearing stack to restrict the motion at pole faces. A composite flywheel was made using a multi-ring interference assembled design for a high specific energy density. To achieve a higher speed and better efficiency, a permanent magnet DC brushless motor was specially designed and fabricated. A vacuum enclosure was constructed to eliminate windage losses for testing at high speeds. With the new improvements the OCCF system was tested to 20,000 RPM with a total stored energy of 15.9 WH and an angular momentum of 54.8 N-m-s (40.4 lb-ft-s). Motor current limitation, caused by power loss in the magnetic bearings, was identified as causing the limit in upper operating speed.

Pang, D.; Anand, D. K. (Editor); Kirk, J. A. (Editor)

1996-01-01

179

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

2012-09-12

180

Explication of design data of the graphite structural design code for core support components of High Temperature Engineering Test Reactor.  

National Technical Information Service (NTIS)

The graphite and carbon materials used for the core support graphite components of High Temperature Engineering Test Reactor (HTTR) are nuclear grade fine-grained isotropic graphite (IG-110), nuclear grade medium-grained near-isotropic graphite (PGX) and ...

M. Ishihara T. Iyoku S. Sato S. Shiozawa J. Toyota

1991-01-01

181

Designing fast LTL model checking algorithms for many-core GPUs  

Microsoft Academic Search

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

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

182

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

Microsoft Academic Search

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

T D NEWTON

183

The Practical Turn in Teacher Education: Designing a Preparation Sequence for Core Practice Frames  

ERIC Educational Resources Information Center

Amid calls for more practice-based teacher education, this article presents a concrete illustration of a practice-based bridging strategy for preparing high school biology teachers to enact open-inquiry labs. Open-inquiry labs were considered a core practice frame that served as a context for identifying core practices and for giving coherence to…

Janssen, Fred; Westbroek, Hanna; Doyle, Walter

2014-01-01

184

Design and performance analysis of high-order optical temporal differentiator with twin-core fiber  

NASA Astrophysics Data System (ADS)

A simple and general approach for implementing all-fiber high-order optical temporal differentiator based on twin-core fiber (TCF) is presented and demonstrated. Specifically, the core 2 (or core 1) of the TCF should be cut in N sections with the same length for achieving N'th-order optical temporal differentiator, which can be considered to consist of N cascaded first-order optical temporal differentiators based on TCF. Our simulations show that the proposed approach can provide optical operation bandwidths in the several THz regime, which is capable of accurately processing time features as short as subpicoseconds. Performance analysis results show a good accuracy calculating the high-order time differentiation of the optical signal launched at core 2 (or core 1).

You, Haidong; Ning, Tigang; Li, Jing; Jian, Wei; Wen, Xiaodong; Pei, Li

2013-08-01

185

Three-dimensional Core Design of High Temperature Supercritical-Pressure Light Water Reactor with Neutronic and Thermal-Hydraulic Coupling  

Microsoft Academic Search

The equilibrium core of the High Temperature Supercritical-Pressure Light Water Reactor (SCLWR-H) is designed by three-dimensional neutronic and thermal-hydraulic coupled core calculations. The average coolant core outlet temperature of 500°C is accurately evaluated for the first time in the development of the SCLWR-H.The average coolant core outlet temperature is one of the key parameters, which must be accurately determined in

Akifumi YAMAJI; Yoshiaki OKA; Seiichi KOSHIZUKA

2005-01-01

186

Design study of an air pump and integral lift engine ALF-504 using the Lycoming 502 core  

NASA Technical Reports Server (NTRS)

Design studies were conducted for an integral lift fan engine utilizing the Lycoming 502 fan core with the final MQT power turbine. The fan is designed for a 12.5 bypass ratio and 1.25:1 pressure ratio, and provides supercharging for the core. Maximum sea level static thrust is 8370 pounds with a specific fuel consumption of 0.302 lb/hr-lb. The dry engine weight without starter is 1419 pounds including full-length duct and sound-attenuating rings. The engine envelope including duct treatment but not localized accessory protrusion is 53.25 inches in diameter and 59.2 inches long from exhaust nozzle exit to fan inlet flange. Detailed analyses include fan aerodynamics, fan and reduction gear mechanical design, fan dynamic analysis, engine noise analysis, engine performance, and weight analysis.

Rauch, D.

1972-01-01

187

Thermal/mechanical simulation and laboratory fatigue testing of an alternative yttria tetragonal zirconia polycrystal core-veneer all-ceramic layered crown design.  

PubMed

This study evaluated the stress levels at the core layer and the veneer layer of zirconia crowns (comprising an alternative core design vs. a standard core design) under mechanical/thermal simulation, and subjected simulated models to laboratory mouth-motion fatigue. The dimensions of a mandibular first molar were imported into computer-aided design (CAD) software and a tooth preparation was modeled. A crown was designed using the space between the original tooth and the prepared tooth. The alternative core presented an additional lingual shoulder that lowered the veneer bulk of the cusps. Finite element analyses evaluated the residual maximum principal stresses fields at the core and veneer of both designs under loading and when cooled from 900 degrees C to 25 degrees C. Crowns were fabricated and mouth-motion fatigued, generating master Weibull curves and reliability data. Thermal modeling showed low residual stress fields throughout the bulk of the cusps for both groups. Mechanical simulation depicted a shift in stress levels to the core of the alternative design compared with the standard design. Significantly higher reliability was found for the alternative core. Regardless of the alternative configuration, thermal and mechanical computer simulations showed stress in the alternative core design comparable and higher to that of the standard configuration, respectively. Such a mechanical scenario probably led to the higher reliability of the alternative design under fatigue. PMID:20487011

Bonfante, Estevam A; Rafferty, Brian; Zavanelli, Ricardo A; Silva, Nelson R F A; Rekow, Elizabeth D; Thompson, Van P; Coelho, Paulo G

2010-04-01

188

Universal Design for Learning: speech-language pathologists and their teams making the common core curriculum accessible.  

PubMed

The Universal Design for Learning (UDL) framework was named in the supporting documents for the Common Core State Standards (CCSS) as a means of helping all students, especially those with disabilities, to meet and exceed the rigorous expectations. This article will describe the principles of UDL, show how educational teams use the framework to design instruction to teach the CCSS with examples from science and English language arts, and finally explore how the implementation of UDL provides an opportunity for speech-language pathologists to play a critical role in school improvement and instructional design and support. PMID:22538708

Staskowski, Maureen; Hardin, Susan; Klein, Mike; Wozniak, Carrie

2012-05-01

189

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

SciTech Connect

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

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

1995-12-31

190

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

191

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

192

Using DEMATEL method to explore the core competences and causal effect of the IC design service company: An empirical case study  

Microsoft Academic Search

The booming of Integrated Circuit (IC) design service has become a critical sub-industry to the evolution of semiconductor industry. In this paper, we took the case of a tier one IC design service company to explore the core competences of this emerging industry. Seven core competences are defined throughout the research. More specifically, this paper analyzes the in-depth of the

Ya-Ti Lin; Yeou-Herng Yang; Jin-Su Kang; Hsiao-Cheng Yu

2011-01-01

193

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

194

Design and optimization of broadband and polarization-insensitive dual-core photonic crystal fiber coupler.  

PubMed

In this paper, we propose a novel (to our knowledge) broadband and polarization-insensitive dual-core photonic crystal fiber (PCF) coupler through the introduction of an elliptical-shaped central air hole to offset the slight birefringence arising from the dual core. With a full vectorial finite element method and anisotropic perfectly matched layers as the external boundaries, the impact of several fiber parameters on the coupling characteristics of dual-core PCF is investigated in detail. Through optimizing the main fiber parameters, including core diameter, size and ellipticity of the central air hole, and refractive index difference, broadband and polarization-insensitive characteristics are achieved in the wavelength range from 0.8 to 1.7 ?m. The variation of the coupling ratio is stabilized at 50±1%, and the coupling ratio difference between x polarization and y polarization is less than 2% over the wavelength range. This dual-core PCF makes it easier to develop a 3 dB coupler over a wide wavelength for passive optical networks and large optical systems. PMID:21556102

Lou, Shuqin; Tang, Zunwei; Wang, Liwen

2011-05-10

195

Design techniques for INL and jitter prediction of a 3.3V 16b 65MSps pipeline ADC core  

Microsoft Academic Search

This work introduces design techniques and experimental results relative to a 16b 65MSps pipeline ADC core implemented in 0.4?m, 45GHz-fr SiGe BiCMOS. A fast methodology for simulating the INL with Spice enables the implementation of low-distortion sample\\/hold and quantizer at 3.3V supply and high input range (4Vpp). Accurate prediction of aperture uncertainty allow the optimization of the on-chip clock circuit,

Alfio Zanchi; Frank Tsay

2005-01-01

196

Design of the processing core of a mixed-signal CMOS DTCNN chip for pixel-level snakes  

Microsoft Academic Search

This paper introduces the processing core of a full-custom mixed-signal CMOS chip intended for an active-contour-based technique, the so-called pixel-level snakes (PLS). Among the different parameters to optimize on the top-down design flow our methodology is focused on area. This approach results in a single-instruction-multiple-data chip implemented by a discrete-time cellular neural network with a correspondence between pixel and processing

V. M. Brea; David L. Vilariño; Ari Paasio; Diego Cabello

2004-01-01

197

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

198

An Evaluation of Server Consolidation Workloads for Multi-Core Designs  

Microsoft Academic Search

While chip multiprocessors with ten or more cores will be feasible within a few years, the search for applications that fully exploit their attributes continues. In the meantime, one sure-fire application for such machines will be to serve as consolidation platforms for sets of workloads that previously occupied multiple discrete systems. Such server consolidation scenarios will simplify system administration and

Natalie Enright Jerger; Dana Vantrease; Mikko Lipasti

2007-01-01

199

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

Microsoft Academic Search

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

Parkash Chander; Henry Tulkens

1995-01-01

200

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

Microsoft Academic Search

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

B. Curwen; L. H. Franklin

1983-01-01

201

C2 Core and UCore Message Design Capstone: Interoperable Message Structure.  

National Technical Information Service (NTIS)

UCore allows users to create multi-layered messages pairing UCore digests with detailed structured payloads. A MITRE Capstone was funded to explore the feasibility of a multi-layered message including a domain specific common core layer. The Capstone Team...

C. Macheret M. A. Malloy M. D. Allen

2009-01-01

202

Using electronic meeting system support in the design of the graduate core curriculum  

Microsoft Academic Search

This article focuses on the use of an electronic meeting system (EMS) to facilitate the selection and refinement of a set of common graduate core courses for all master's degrees within the school of education in an upper-division university. The EMS was used at selected intervals within a seven months' process and provided an opportunity for broad-based group involvement in

Dennis W. Spuck; Doris L. Prater; David B. Palumbo

1995-01-01

203

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

204

Effective Web Design and Core Communication Issues: The Missing Components in Web-Based Distance Education.  

ERIC Educational Resources Information Center

Discussion of Web-based distance education focuses on communication issues. Highlights include Internet communications; components of a Web site, including site architecture, user interface, information delivery method, and mode of feedback; elements of Web design, including conceptual design, sensory design, and reactive design; and a Web…

Burch, Randall O.

2001-01-01

205

Design and test of-80 kV snubber core assemblies for MFTF sustaining-neutral-beam power supplies  

SciTech Connect

Core snubbers, located near the neutral beam source ends of the Mirror Fusion Test Facility (MFTF) Sustaining Neutral Beam Power Supply System (SNBPSS) source cables, protect the neutral beam source extractor grid wires from overheating and sputtering during internal sparkdowns. The snubbers work by producing an induced counter-emf which limits the fault current and by absorbing the capacitive energy stored on the 80 kV source cables and power supplies. A computer program STACAL was used in snubber magnetic design to choose appropriate tape wound cores to provide 400 ..cap omega.. resistance and 25 J energy absorption. The cores are mounted horizontally in a dielectric structure. The central source cable bundle passes through the snubber and terminates on three copper buses. Multilam receptacles on the buses connect to the source module jumper cables. Corona rings and shields limit electric field stresses to allow close clearances between snubbers. A filament circuit shunt bias winding wound on a dielectric cylinder surrounds the cores. The dc voltage holdoff of a single snubber has been tested. Current and voltage behavior during capacitor bank and source cable discharges are presented.

Bishop, S.R.; Mayhall, D.J.; Wilson, J.H.; De Vore, K.R.; Ross, R.I.; Sears, R.G.

1981-10-09

206

The role of plastic ?-hairpin and weak hydrophobic core in the stability and unfolding of a full sequence design protein  

NASA Astrophysics Data System (ADS)

In this study, the thermal stability of a designed ?/? protein FSD (full sequence design) was studied by explicit solvent simulations at three moderate temperatures, 273 K, 300 K, and 330 K. The average properties of the ten trajectories at each temperature were analyzed. The thermal unfolding, as judged by backbone root-mean-square deviation and percentage of native contacts, was displayed with increased sampling outside of the native basin as the temperature was raised. The positional fluctuation of the hairpin residues was significantly higher than that of the helix residues at all three temperatures. The hairpin segment displayed certain plasticity even at 273 K. Apart from the terminal residues, the highest fluctuation was shown in the turn residues 7-9. Secondary structure analysis manifested the structural heterogeneity of the hairpin segment. It was also revealed by the simulation that the hydrophobic core was vulnerable to thermal denaturation. Consistent with the experiment, the I7Y mutation in the double mutant FSD-EY (FSD with mutations Q1E and I7Y) dramatically increased the protein stability in the simulation, suggesting that the plasticity of the hairpin can be partially compensated by a stronger hydrophobic core. As for the unfolding pathway, the breathing of the hydrophobic core and the separation of the two secondary structure elements (? helix and ? hairpin) was the initiation step of the unfolding. The loss of global contacts from the separation further destabilized the hairpin structure and also led to the unwinding of the helix.

Lei, Hongxing; Duan, Yong

2004-12-01

207

Evaluation of the Effect of Different Ferrule Designs on Fracture Resistance of Maxillary Incisors Restored with Bonded Posts and Cores  

PubMed Central

Introduction: In cases of severe hard tissue loss, 2 mm circumferential ferrule is difficult to achieve. So in these cases we should use different ferrule designs. This in vitro study investigated the effect of different ferrule designs on the fracture resistance of teeth restored with bonded post and cores. Materials and Methods: Forty freshly-extracted central incisors were endodontically treated. The teeth were randomly divided into four groups; group 1 were teeth with 2 mm circumferential ferrule above the CEJ, group 2 were teeth with 2 mm ferrule only on the palatal side of the teeth, group 3 consisted of teeth with 2 mm ferrule only on the facial side and group 4 were teeth with 2 mm ferrule on the palatal and facial side of teeth with interproximal concavities. All teeth were restored with fiber posts and composite cores. The specimen was mounted on a universal testing machine and compressive load was applied to the long axis of the specimen until failure occurred. Results: The fracture resistance was 533.79 ± 232.28 in group 1, 634.75± 133.35 in group 2, 828.90 ±118.27 in group 3 and 678.78± 160.20 in group 4. The post hoc analysis showed statistically significant difference between groups 1 and 3. Conclusions: The results of this in vitro study showed that facial ferrule increases the fracture resistance of endodontically treated teeth restored with bonded post and cores.

Mahdavi Izadi, Z.; Jalalian, E.; Eyvaz Ziaee, A.; Zamani, L.; Javanshir, B.

2010-01-01

208

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

209

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

Microsoft Academic Search

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

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

2011-01-01

210

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

211

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

NASA Technical Reports Server (NTRS)

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

1992-01-01

212

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

213

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

214

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

215

Investigation into the role of core industrial designers in ecodesign projects  

Microsoft Academic Search

Current ecodesign theory supports the belief that industrial designers have a valuable role to play in ecodesign because of their position at the early stages of the product development process (Integrating Environmental Decisions into the Product Development Process: Part 1 The Early Stages. Ecodesign ‘99: First Symposium on Environmentally Conscious Design and Inverse Manufacture IEEE, Tokyo, Japan, February 1–3, 1999

Vicky Lofthouse

2004-01-01

216

Design and optimization study of 10,000 MW(e) very large fast reactor core  

Microsoft Academic Search

To answer the increasing demand for electric power in Japan, very large ; fast reactors of 10,000 MW(e) unit capacity are expected to make their appearance ; in due course. The method and results of a design study on a 10,000 MW(e) Liquid ; Metal Fast Breeder Reactor are described. First, a reference design was obtained ; for this unprecedented

Yasuhiro KOBAYASHI; Shunsuke KONDO; Yasumasa TOGO

1973-01-01

217

DESIGN CALCULATIONS OF JRR-3 (NATURAL URANIUM HEAVY-WATER RESEARCH REACTOR). PART 1. CORE CALCULATIONS  

Microsoft Academic Search

The paper shows the nuclear design calculation for the Japan-made ; reactor No. 1 (JRR-3), a 10 Mw natural uranium heavy-water research reactor. At ; the present stage of the nuclear design calculation an accurate and simple method ; is not available, so a few lattice parameters must be set from the preliminary ; calculation and then a more accurate

H. Ishikawa; T. Asaoka; Y. Sasakura

1959-01-01

218

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

SciTech Connect

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

B. Boer; A. M. Ougouag

2010-09-01

219

Design Novel Dual Agonists for Treating Type-2 Diabetes by Targeting Peroxisome Proliferator-Activated Receptors with Core Hopping Approach  

PubMed Central

Owing to their unique functions in regulating glucose, lipid and cholesterol metabolism, PPARs (peroxisome proliferator-activated receptors) have drawn special attention for developing drugs to treat type-2 diabetes. By combining the lipid benefit of PPAR-alpha agonists (such as fibrates) with the glycemic advantages of the PPAR-gamma agonists (such as thiazolidinediones), the dual PPAR agonists approach can both improve the metabolic effects and minimize the side effects caused by either agent alone, and hence has become a promising strategy for designing effective drugs against type-2 diabetes. In this study, by means of the powerful “core hopping” and “glide docking” techniques, a novel class of PPAR dual agonists was discovered based on the compound GW409544, a well-known dual agonist for both PPAR-alpha and PPAR-gamma modified from the farglitazar structure. It was observed by molecular dynamics simulations that these novel agonists not only possessed the same function as GW409544 did in activating PPAR-alpha and PPAR-gamma, but also had more favorable conformation for binding to the two receptors. It was further validated by the outcomes of their ADME (absorption, distribution, metabolism, and excretion) predictions that the new agonists hold high potential to become drug candidates. Or at the very least, the findings reported here may stimulate new strategy or provide useful insights for discovering more effective dual agonists for treating type-2 diabetes. Since the “core hopping” technique allows for rapidly screening novel cores to help overcome unwanted properties by generating new lead compounds with improved core properties, it has not escaped our notice that the current strategy along with the corresponding computational procedures can also be utilized to find novel and more effective drugs for treating other illnesses.

Xu, Wei-Ren; Wang, Run-Ling; Chou, Kuo-Chen

2012-01-01

220

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

NASA Technical Reports Server (NTRS)

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

Howard, Samuel A.

2007-01-01

221

Physics Implications of Oxide and Metal Fuel on the Design of Small LMFBR Cores.  

National Technical Information Service (NTIS)

In order to maintain momentum in the US LMFBR program, much attention has recently been focused on the possibility of new design approaches consistent with the slower deployment scenarios currently envisioned. To this end, the slower rate of deployment of...

Y. Orechwa H. Khalil

1984-01-01

222

Core and Refueling Design Studies for the Advanced High Temperature Reactor  

Microsoft Academic Search

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

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

2011-01-01

223

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

Microsoft Academic Search

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

1995-01-01

224

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

NASA Technical Reports Server (NTRS)

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

Smith, Kurt R.

2013-01-01

225

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

226

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

SciTech Connect

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

Hammer, C.F.

1983-01-01

227

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

228

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

Microsoft Academic Search

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

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

1971-01-01

229

CopperCore Service Integration - Integrating IMS Learning Design and IMS Question and Test Interoperability  

Microsoft Academic Search

This article describes a framework for the integration of e-Learning services. There is a need for this type of integration in general, but the presented solution was a direct result of work done on the IMS Learning Design specification (LD). This specification relies heavily on other specifications and services. The presented architecture is described using the example of two of

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

2006-01-01

230

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

Microsoft Academic Search

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

Y. Orechwa; H. Khalil

1984-01-01

231

The performance of 3500 MWth homogeneous and heterogeneous metal fueled core designs  

SciTech Connect

Performance parameters are calculated for a representative 3500 MWth homogeneous and a heterogeneous metal fueled reactor design. The equilibrium cycle neutronic characteristics, safety coefficients, control system requirements, and control rod worths are evaluated. The thermal-hydraulic characteristics for both configurations are also compared. The heavy metal fuel loading requirements and neutronic performance characteristics are also evaluated for the uranium startup option. 14 refs., 14 figs., 20 tabs.

Turski, R.; Yang, Shi-tien

1987-11-01

232

Rethinking DRAM design and organization for energy-constrained multi-cores  

Microsoft Academic Search

DRAM vendors have traditionally optimized the cost-per-bit metric, often making design decisions that incur energy penalties. A prime example is the overfetch feature in DRAM, where a single request activates thousands of bit-lines in many DRAM chips, only to return a single cache line to the CPU. The focus on cost-per-bit is questionable in modern-day servers where operating costs can

Aniruddha N. Udipi; Naveen Muralimanohar; Niladrish Chatterjee; Rajeev Balasubramonian; Al Davis; Norman P. Jouppi

2010-01-01

233

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

234

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

SciTech Connect

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

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

2011-01-02

235

From ab initio calculations to multiscale design of Si/C core-shell particles for Li-ion anodes.  

PubMed

The design of novel Si-enhanced nanocomposite electrodes that will successfully mitigate mechanical and chemical degradation is becoming increasingly important for next generation Li-ion batteries. Recently Si/C hollow core-shell nanoparticles were proposed as a promising anode architecture, which can successfully sustain thousands of cycles with high Coulombic efficiency. As the structural integrity and functionality of these heterogeneous Si materials depend on the strength and fracture energy of the active materials, an in-depth understanding of the interface and their intrinsic mechanical properties, such as fracture strength and debonding, becomes critical for the successful design of such and similar composites. Here, we first perform ab initio simulations to calculate these properties for lithiated a-Si/a-C interface structures and combine these results with linear elasticity expressions to model conditions that will avert fracture and debonding in these heterostructures. We find that the a-Si/a-C interface retains good adhesion even at high stages of lithiation. For average lithiated structures, we predict that the strong Si-C bonding averts fracture at the interface; instead, the structure ruptures within lithiated a-Si. From the calculated values and linear elastic fracture mechanics, we then construct a continuum level diagram, which outlines the safe regimes of operation in terms of the core and shell thickness and the state of charge. We believe that this multiscale approach can serve as a foundation for developing quantitative failure models and for subsequent development of flaw-tolerant anode architectures. PMID:24611810

Stournara, Maria E; Qi, Yue; Shenoy, Vivek B

2014-04-01

236

Electrical design of a high current density air-core reversed-field pinch ZTP  

SciTech Connect

This paper describes the electrical design of a small, high current density (10 MA/m/sup 2/) toroidal reversed-field Z-Pinch (RFP) presently being constructed at Los Alamos. Special purpose magnetic field programs were used to calculate self and mutual inductances for the poloidal field windings. The network analysis program MINI-SCEPTRE was then used to predict plasma current, including the interaction between toroidal and poloidal field circuits, as described by the Bessel function model for RFP's. Using these programs, coil geometry was obtained for minimal field errors and the pulse power systems were optimized to minimize equilibrium control power. Results of computer modeling and implementation of the electrical circuits are presented.

Reass, W.A.; Melton, J.G.; Gribble, R.F.

1983-01-01

237

Design of inhibitors of the HIV-1 integrase core domain using virtual screening.  

PubMed

Acquired immunodeficiency syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV). The integrase (IN) enzyme of HIV interacts with several cellular and viral proteins during the integration process. Thus, it represents an appropriate target for antiretroviral drugs (ARVs). We performed virtual screening of database compounds and designed analogues using Elvitegravir (EVG) as a standard compound. The 378 screened compounds were retrieved from ZINC, ChemSpider, PubChem, and ChemBank Chemical Databases based on chemical similarity and literature searches related to the structure of EVG. The Physiochemical properties, Bioactivity, Toxicity and Absorption, Distribution, Metabolism and Excretion of Molecules (ADME) of these compounds were predicted and docking Experiments were conducted using Molegro Virtual Docker software. The docking and ADME suggested very significant results in regard to EVG. The MolDock and Rerank scores were used to analyze the results. The compounds ZINC26507991 (-84.22), Analogue 9 (-68.49), ZINC20731658 (-66.79), ZINC00210363 (-43.44) showed better binding orientation with IN receptor model with respect to EVG (182.52). The ZINC26507991 has showed significant ADME result. PMID:24616558

Regon, Preetom; Gogoi, Dhrubajyoti; Rai, Ashok Kumar; Bordoloi, Manabjyoti; Bezbaruah, Rajib Lochan

2014-01-01

238

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.

239

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

SciTech Connect

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. [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka 311-0193 (Japan)] [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka 311-0193 (Japan)

2013-09-15

240

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

241

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

NASA Technical Reports Server (NTRS)

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

1976-01-01

242

Tech Prep Degree: Preparing Tomorrow's Workforce. Design, Development and Implementation of a TECH PREP Core Program. Final Report.  

ERIC Educational Resources Information Center

A four-stage project was undertaken to develop an exemplary tech prep core program to serve students in the Quad-City/Tri-County Vo Tech Regions school districts and Black Hawk Community College (BHCC) in Illinois. A core group planning committee consisting of education and business/industry representatives used the DACUM (Developing a Curriculum)…

Quad-City/Tri-County Vocational Regions, East Moline, IL.

243

Coring Sample Acquisition Tool  

NASA Technical Reports Server (NTRS)

A sample acquisition tool (SAT) has been developed that can be used autonomously to sample drill and capture rock cores. The tool is designed to accommodate core transfer using a sample tube to the IMSAH (integrated Mars sample acquisition and handling) SHEC (sample handling, encapsulation, and containerization) without ever touching the pristine core sample in the transfer process.

Haddad, Nicolas E.; Murray, Saben D.; Walkemeyer, Phillip E.; Badescu, Mircea; Sherrit, Stewart; Bao, Xiaoqi; Kriechbaum, Kristopher L.; Richardson, Megan; Klein, Kerry J.

2012-01-01

244

Building core capacities at the designated points of entry according to the International Health Regulations 2005: a review of the progress and prospects in Taiwan.  

PubMed

Background: As designated points of entry (PoEs) play a critical role in preventing the transmission of international public health risks, huge efforts have been invested in Taiwan to improve the core capacities specified in the International Health Regulations 2005 (IHR 2005). This article reviews how Taiwan strengthened the core capacities at the Taoyuan International Airport (TIA) and the Port of Kaohsiung (PoK) by applying a new, practicable model. Design: An IHR PoE program was initiated for implementing the IHR core capacities at designated PoEs. The main methods of this program were 1) identifying the designated PoEs according to the pre-determined criteria, 2) identifying the competent authority for each health measure, 3) building a close collaborative relationship between stakeholders from the central and PoE level, 4) designing three stages of systematic assessment using the assessment tool published by the World Health Organization (WHO), and 5) undertaking action plans targeting the gaps identified by the assessments. Results: Results of the self-assessment, preliminary external assessment, and follow-up external assessment revealed a continuous progressive trend at the TIA (86, 91, and 100%, respectively), and at the PoK (77, 97, and 99.9%, respectively). The results of the follow-up external assessment indicated that both these designated PoEs already conformed to the IHR requirements. These achievements were highly associated with strong collaboration, continuous empowerment, efficient resource integration, and sustained commitments. Conclusions: Considering that many countries had requested for an extension on the deadline to fulfill the IHR 2005 core capacity requirements, Taiwan's experiences can be a source of learning for countries striving to fully implement these requirements. Further, in order to broaden the scope of public health protection into promoting global security, Taiwan will keep its commitments on multisectoral cooperation, human resource capacity building, and maintaining routine and emergency capacities. PMID:25037903

Chiu, Hsiao-Hsuan; Hsieh, Jui-Wei; Wu, Yi-Chun; Chou, Jih-Haw; Chang, Feng-Yee

2014-01-01

245

OECD MCCI Project. Long-Term 2-D Molten Core Concrete Interaction Test Design Report. Revision 0.  

National Technical Information Service (NTIS)

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...

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

2002-01-01

246

Design and formation mechanism of self-organized core/shell structure composite powder in immiscible liquid system  

NASA Astrophysics Data System (ADS)

Under the guidance of the calculation of phase diagrams method, the self-organized Cu alloy/stainless steel composite powders with a core/shell microstructure were developed based on the gas atomization process, and the formation evolution of self-organized core/shell structure composite powders was modeled by the phase field method. This paper gives a more detailed explanation for the formation of self-organized core/shell structure composite powders from the viewpoints of thermodynamics and kinetics. Such core/shell structure composite powders have good combination of high strength and corrosion resistance (Fe-rich phase) and high electric and thermal conductivities (Cu-rich phase) with many potential advanced applications in electronic devices.

Wang, Cui Ping; Liu, Xing Jun; Shi, Rong Pei; Shen, Chen; Wang, Yunzhi; Ohnuma, Ikuo; Kainuma, Ryosuke; Ishida, Kiyohito

2007-10-01

247

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

248

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

SciTech Connect

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.

Michael A. Pope

2011-10-01

249

Designing one dimensional Co-Ni/Co3O4-NiO core/shell nano-heterostructure electrodes for high-performance pseudocapacitor  

NASA Astrophysics Data System (ADS)

A high-performance supercapacitor electrode based on unique 1D Co-Ni/Co3O4-NiO core/shell nano-heterostructures is designed and fabricated. The nano-heterostructures exhibit high specific capacitance (2013 F g-1 at 2.5 A g-1), high energy and power density (23 Wh kg-1 and 5.5 kW kg-1, at the discharge current density of 20.8 A g-1), good capacitance retention and long cyclicality. The remarkable electrochemical property of the large surface area nano-heterostructures is demonstrated based on the effective nano-architectural design of the electrode with the coexistence of the two highly redox active materials at the surface supported by highly conducting metal alloy channel at the core for faster charge transport.

Singh, Ashutosh K.; Sarkar, Debasish; Gopal Khan, Gobinda; Mandal, Kalyan

2014-03-01

250

Design, construction, commissioning and use of a new cadmium-lined in-core irradiation tube for the Oregon State University TRIGA Reactor  

SciTech Connect

As a result of several requests from reactor users, it was recently decided to install a new cadmium-lined in-core irradiation tube (CLICIT) in the Oregon State University TRIGA Reactor (OSTR). As the title implies, this paper will describe the complete sequence of this process, from the design, and design constraints through manufacture to the actual use of the tube. The design is such that it offers a significant degree of flexibility in use, while still strictly adhering to ALARA concepts. In order to keep costs down, the facility was designed, installed and commissioned by the Oregon State University TRIGA Reactor (OSTR) staff and fabricated locally. As this facility is relatively cheap (about $2,000), and will fit all non-conversion TRIGAs other reactor owners may be interested in copying the OSTR tube design. (author)

Dodd, B.; Anderson, T.V

1990-07-01

251

Design and evaluation of hydrophobic coated buoyant core as floating drug delivery system for sustained release of cisapride  

PubMed Central

An inert hydrophobic buoyant coated–core was developed as floating drug delivery system (FDDS) for sustained release of cisapride using direct compression technology. Core contained low density, porous ethyl cellulose, which was coated with an impermeable, insoluble hydrophobic coating polymer such as rosin. It was further seal coated with low viscosity hydroxypropyl methyl cellulose (HPMC E15) to minimize moisture permeation and better adhesion with an outer drug layer. It was found that stable buoyant core was sufficient to float the tablet more than 8 h without the aid of sodium bicarbonate and citric acid. Sustained release of cisapride was achieved with HPMC K4M in the outer drug layer. The floating lag time required for these novel FDDS was found to be zero, however it is likely that the porosity or density of the core is critical for floatability of these tablets. The in vitro release pattern of these tablets in simulated gastric fluid showed the constant and controlled release for prolonged time. It can be concluded that the hydrophobic coated buoyant core could be used as FDDS for gastroretentive delivery system of cisapride or other suitable drugs.

Jacob, Shery; Nair, Anroop B; Patil, Pandurang N

2010-01-01

252

Design and synthesis of degradation-resistant core-shell catalysts for proton exchange membrane fuel cells  

NASA Astrophysics Data System (ADS)

Core@shell catalysts supported on carbon with Ag core and Pt shell were synthesized by a chemical process. EDX spectra confirmed the formation of Ag@Pt core-shell catalysts. High resolution transmission electron microscopy (HRTEM) revealed that the Pt-shell was epitaxially matched to the Ag core. Electrochemical tests on proton exchange membrane (PEM) fuel cells made with Ag@Pt core-shell catalysts as cathode exhibited comparable performance to cells made using commercial Pt-Co-based catalysts as cathodes. Theoretical work suggested that Ag@Pt catalysts should be more stable in the PEMFC applications compared to monolithic Pt catalysts because Pt shell in Ag@Pt catalysts exhibits lower chemical potential of Pt than in monolithic Pt catalysts, thus reducing tendency for dissolution and Ostwald ripening. Lower chemical potential of Pt in the shell is attributed to larger lattice parameter of Ag compared to Pt, which puts the Pt shell in biaxial tension or reduced biaxial compression as compared to monolithic Pt catalysts. Preliminary out-of-cell tests show Ag@Pt catalysts to be stable in an environment containing ionic platinum.

Koh, Joon-Ho; Abbaraju, Ravikanth; Parthasarathy, Preethy; Virkar, Anil V.

2014-09-01

253

Design Study for a Low-Enriched Uranium Core for the High Flux Isotope Reactor, Annual Report for FY 2006  

SciTech Connect

Neutronics and thermal-hydraulics studies show that, for equivalent operating power [85 MW(t)], a low-enriched uranium (LEU) fuel cycle based on uranium-10 wt % molybdenum (U-10Mo) metal foil with radially, “continuously graded” fuel meat thickness results in a 15% reduction in peak thermal flux in the beryllium reflector of the High Flux Isotope Reactor (HFIR) as compared to the current highly enriched uranium (HEU) cycle. The uranium-235 content of the LEU core is almost twice the amount of the HEU core when the length of the fuel cycle is kept the same for both fuels. Because the uranium-238 content of an LEU core is a factor of 4 greater than the uranium-235 content, the LEU HFIR core would weigh 30% more than the HEU core. A minimum U-10Mo foil thickness of 84 ?m is required to compensate for power peaking in the LEU core although this value could be increased significantly without much penalty. The maximum U-10Mo foil thickness is 457?m. Annual plutonium production from fueling the HFIR with LEU is predicted to be 2 kg. For dispersion fuels, the operating power for HFIR would be reduced considerably below 85 MW due to thermal considerations and due to the requirement of a 26-d fuel cycle. If an acceptable fuel can be developed, it is estimated that $140 M would be required to implement the conversion of the HFIR site at Oak Ridge National Laboratory from an HEU fuel cycle to an LEU fuel cycle. To complete the conversion by fiscal year 2014 would require that all fuel development and qualification be completed by the end of fiscal year 2009. Technological development areas that could increase the operating power of HFIR are identified as areas for study in the future.

Primm, R. T. [ORNL] [ORNL; Ellis, R. J. [ORNL] [ORNL; Gehin, J. C. [ORNL] [ORNL; Clarno, K. T. [ORNL] [ORNL; Williams, K. A. [ORNL] [ORNL; Moses, D. L. [ORNL] [ORNL

2006-11-01

254

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

Microsoft Academic Search

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

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

2003-01-01

255

Attaining system performance points: revisiting the end-to-end argument in system design for heterogeneous many-core systems  

Microsoft Academic Search

Trends indicate a rapid increase in the number of cores on chip, exhibiting various types of performance and functional asymmetries present in hardware to gain scalability with balanced power vs. performance requirements. This poses new challenges in platform resource management, which are further exacerbated by the need for runtime power budgeting and by the increased dynamics in workload behavior observed

Vishakha Gupta; Rob C. Knauerhase; Karsten Schwan

2011-01-01

256

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

Microsoft Academic Search

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,

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

2011-01-01

257

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

258

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

259

Design of 154 kV class 100 MVA 3 phase HTS transformer on a common magnetic core  

Microsoft Academic Search

We have proposed a high temperature superconducting (HTS) transformer which can substitute for a conventional oil transformer for power distribution in Korea. The conventional transformer is composed of three identical single phase transformers because of the limitations on volume and weight. Now the Korean power company has started to consider the possibility of a transformer on a common magnetic core

J. Choi; S. Lee; W. Kim; S. Kim; J. Han; H. Lee; K. Choi

2007-01-01

260

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

261

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

National Technical Information Service (NTIS)

The system this document describes controls several functions of the Core Sample Truck(s) used to obtain nuclear waste samples from various underground storage tanks at Hanford. The system will monitor the sampling process and provide alarms and other fee...

J. L. Dowell J. C. Akers

1995-01-01

262

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

NASA Astrophysics Data System (ADS)

This study is for modeling and designing a new reactor core-moderator assembly and new neutron beam ports that aimed to expand utilization of a new beam hall of the Penn State Breazeale Reactor (PSBR). The PSBR is a part of the Radiation Science and Engineering Facility (RSEC) and is a TRIGA MARK III type research reactor with a movable core placed in a large pool and is capable to produce 1MW output. This reactor is a pool-type reactor with pulsing capability up to 2000 MW for 10-20 msec. There are seven beam ports currently installed to the reactor. The PSBR's existing core design limits the experimental capability of the facility, as only two of the seven available neutron beam ports are usable. The finalized design features an optimized result in light of the data obtained from neutronic and thermal-hydraulics analyses as well as geometrical constraints. A new core-moderator assembly was introduced to overcome the limitations of the existing PSBR design, specifically maximizing number of available neutron beam ports and mitigating the hydrogen gamma contamination of the neutron beam channeled in the beam ports. A crescent-shaped moderator is favored in the new PSBR design since it enables simultaneous use of five new neutron beam ports in the facility. Furthermore, the crescent shape sanctions a coupling of the core and moderator, which reduces the hydrogen gamma contamination significantly in the new beam ports. A coupled MURE and MCNP5 code optimization analysis was performed to calculate the optimum design parameters for the new PSBR. Thermal-hydraulics analysis of the new design was achieved using ANSYS Fluent CFD code. In the current form, the PSBR is cooled by natural convection of the pool water. The driving force for the natural circulation of the fluid is the heat generation within the fuel rods. The convective heat data was generated at the reactor's different operating powers by using TRIGSIMS, the fuel management code of the PSBR core. In the CFD modeling, the amount of heat generated by the fuel is assumed to be transferred totally into the coolant. Therefore, the surface heat flux is applied to the fuel cladding outer surface by considering the depleted fuel composition of each individual fuel rod under a reference core loading condition defined as; 53H at 1MW full power. In order to model the entire PSBR reactor, fine mesh discretization was achieved with 22 millions structured and unstructured computational meshes. The conductive heat transfer inside the fuel rods was ignored in order to decrease the computational mesh requirement. Since the PSBR core operates in the subcooled nucleate boiling region, the CFD simulation of new PSBR design was completed utilizing an Eulerian-Eulerian multiphase flow formulation and RPI wall boiling model. The simulation results showed that the new moderator tank geometry results in secondary flow entering into the core due to decrease in the cross-flow area. Notably, the radial flow improves the local heat transfer conditions by providing radial-mixing in the core. Bubble nucleation occurs on the heated fuel rods but bubbles are collapsing in the subcooled fluid. Furthermore, the bulk fluid properties are not affected by the bubble formation. Yet, subcooled boiling enhances the heat transfer on the fuel rods. Five neutron beam ports are designed for the new reactor. The geometrical configuration, filter and collimator system designs of each neutron beam ports are selected based on the requirements of the experimental facilities. A cold neutron beam port which utilizes cold neutrons from three curved guide tubes is considered. Therefore, there will be seven neutron beams available in the new facility. The neutronic analyses of the new beam port designs were achieved by using MCNP5 code and Burned Coupled Simulation Tool for the PSBR. The MCNP simulation results showed that thermal neutron flux was increased by a factor of minimum 1.23 times and maximum 2.68 times in the new beam port compared to the existing BP4 design. Besides total gamma dose was decreased by a factor

Ucar, Dundar

263

Design and characterization of core-shell mPEG-PLGA composite microparticles for development of cell-scaffold constructs.  

PubMed

Appropriate scaffolds capable of providing suitable biological and structural guidance are of great importance to generate cell-scaffold constructs for cell-based tissue engineering. The aim of the present study was to develop composite microparticles with a structure to provide functionality as a combined drug delivery/scaffold system. Composite microparticles were produced by incorporating either alginate/dermatan sulfate (Alg/DS) or alginate/chitosan/dermatan sulfate (Alg/CS/DS) particles in mPEG-PLGA microparticles using coaxial ultrasonic atomization. The encapsulation and distribution of Alg/DS or Alg/CS/DS particles in the mPEG-PLGA microparticles were significantly dependent on the operating conditions, including the flow rate ratio (Qout/Qin) and the viscosity of the polymer solutions (Vout, Vin) between the outer and the inner feeding channels. The core-shell composite microparticles containing the Alg/DS particles or the Alg/CS/DS particles displayed 40% and 65% DS release in 10 days, respectively, as compared to the DS directly loaded microparticles showing 90% DS release during the same time interval. The release profiles of DS correlate with the cell proliferation of fibroblasts, i.e. more sustainable cell growth was induced by the DS released from the core-shell composite microparticles comprising Alg/CS/DS particles. After seeding fibroblasts onto the composite microparticles, excellent cell adhesion was observed, and a successful assembly of the cell-scaffold constructs was induced within 7 days. Therefore, the present study demonstrates a novel strategy for fabrication of core-shell composite microparticles comprising additional particulate drug carriers in the core, which provides controlled delivery of DS and favorable cell biocompatibility; an approach to potentially achieve cell-based tissue regeneration. PMID:23958320

Wen, Yanhong; Gallego, Monica Ramos; Nielsen, Lene Feldskov; Jorgensen, Lene; Møller, Eva Horn; Nielsen, Hanne Mørck

2013-09-01

264

Design of an automotive traffic sign recognition system targeting a multi-core SoC implementation  

Microsoft Academic Search

This paper describes the design of an automotive traffic sign recognition application. All stages of the design process, starting on system-level with an abstract, pure functional model down to final hardware\\/software implementations on an FPGA, are shown. The proposed design flow tackles existing bottlenecks of today's system-level design processes, following an early model-based performance evaluation and analysis strategy, which takes

Matthias Müller; Axel G. Braun; Joachim Gerlach; Wolfgang Rosenstiel; Dennis Nienhüser; Johann Marius Zöllner; Oliver Bringmann

2010-01-01

265

Lead users' ideas on core features to support physical activity in rheumatoid arthritis: a first step in the development of an internet service using participatory design  

PubMed Central

Background Despite the growing evidence of the benefits of physical activity (PA) in individuals with rheumatoid arthritis (RA), the majority is not physically active enough. An innovative strategy is to engage lead users in the development of PA interventions provided over the internet. The aim was to explore lead users’ ideas and prioritization of core features in a future internet service targeting adoption and maintenance of healthy PA in people with RA. Methods Six focus group interviews were performed with a purposively selected sample of 26 individuals with RA. Data were analyzed with qualitative content analysis and quantification of participants’ prioritization of most important content. Results Six categories were identified as core features for a future internet service: up-to-date and evidence-based information and instructions, self-regulation tools, social interaction, personalized set-up, attractive design and content, and access to the internet service. The categories represented four themes, or core aspects, important to consider in the design of the future service: (1) content, (2) customized options, (3) user interface and (4) access and implementation. Conclusions This is, to the best of our knowledge, the first study involving people with RA in the development of an internet service to support the adoption and maintenance of PA. Participants helped identifying core features and aspects important to consider and further explore during the next phase of development. We hypothesize that involvement of lead users will make transfer from theory to service more adequate and user-friendly and therefore will be an effective mean to facilitate PA behavior change.

2014-01-01

266

Design and overall performance of four highly loaded, high speed inlet stages for an advanced high-pressure-ratio core compressor  

NASA Technical Reports Server (NTRS)

The detailed design and overall performances of four inlet stages for an advanced core compressor are presented. These four stages represent two levels of design total pressure ratio (1.82 and 2.05), two levels of rotor aspect ratio (1.19 and 1.63), and two levels of stator aspect ratio (1.26 and 1.78). The individual stages were tested over the stable operating flow range at 70, 90, and 100 percent of design speeds. The performances of the low aspect ratio configurations were substantially better than those of the high aspect ratio configurations. The two low aspect ratio configurations achieved peak efficiencies of 0.876 and 0.872 and corresponding stage efficiencies of 0.845 and 0.840. The high aspect ratio configurations achieved peak ratio efficiencies of 0.851 and 0.849 and corresponding stage efficiencies of 0.821 and 0.831.

Reid, L.; Moore, R. D.

1978-01-01

267

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

SciTech Connect

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

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

1995-08-01

268

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

PubMed

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. PMID:23493921

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

2013-05-01

269

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

Microsoft Academic Search

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

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

2010-01-01

270

Core compressor exit stage study. Volume 5: Design and performance report for the Rotor C/Stator B configuration  

NASA Technical Reports Server (NTRS)

Rear stage blading designs that have lower losses in their endwall boundary layer regions were developed. The design of rotor-C and the performance results for rotor-C running with stator B are described. A low speed research compressor is utilized as the principal investigative tool. Four identical stages of blading are used to obtained data in a true multistage environment.

Wisler, D. C.

1981-01-01

271

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

272

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

2012-07-01

273

Multifunctional superparamagnetic fe3O4@SiO2 core/shell nanoparticles: design and application for cell imaging.  

PubMed

Highly biocompatible sub-50-nm monodisperse superparamagnetic Fe3O4@SiO2 core/shell nanoparticles with luminescent silica shells were synthesized by a w/o-microemulsion technique. And then these nanoparticles were coated with the covalently bonded biocompatible polymer poly(ethylene glycol) (PEG) and modified with the biological cancer targeting ligand folic acid (FA). After characterized by means of powder X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transformed infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), UV-vis, fluorescence spectroscopy and confocal laser scanning microscopy (CLSM), we confirmed that Fe3O4@SiO2 (FITC)-PEG-FA nanocomposites (SMNPs-FA) could be efficiently taken up by HeLa cancer cells and KB cells which are of over-expression of folate receptors. The multifunctional nanomaterials exhibited superparamagnetic, monodisperse, highly biocompatible, intensively fluorescent and capable of recognizing and binding cells that overexpress folate receptors, which would be useful for targeting cell imaging and provide an excellent platform for further development of an efficient cancer therapy. PMID:24738334

Zhao, Xueling; Zhao, Hongli; Yuan, Huihui; Lan, Minbo

2014-02-01

274

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

National Technical Information Service (NTIS)

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 suppo...

M. A. Rezvani H. H. Ziada

1992-01-01

275

Promoting Student-Led Science and Technology Projects in Elementary Teacher Education: Entry into Core Pedagogical Practices through Technological Design  

ERIC Educational Resources Information Center

Future elementary school teachers often lack self-efficacy for teaching science and technology. They are particularly anxious about encouraging children to carry-out student-directed, open-ended scientific inquiry and/or technological design projects. Moreover, because this often also is the case with practising elementary school teachers, it is…

Bencze, John Lawrence

2010-01-01

276

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

277

Case Studies of Leading Edge Small Urban High Schools. Core Academic Strategic Designs: 1. Academy of the Pacific Rim  

ERIC Educational Resources Information Center

This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high schools across the…

Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

2008-01-01

278

Case Studies of Leading Edge Small Urban High Schools. Core Academic Strategic Designs: 3. University Park Campus School  

ERIC Educational Resources Information Center

This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high schools across the…

Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

2008-01-01

279

Towards Evolvable IP Cores for FPGAs  

Microsoft Academic Search

The paper deals with a new approach to the design of adaptive hardware using common Field Programmable Gate Arrays (FPGA). The ultimate aim is to develop evolv- able IP (Intellectual Property) cores. The cores should be reused in the same way as ordinary IP cores are reused. In contrast to the conventional cores, the evolvable cores are able to perform

Boÿ zetÿ echova

280

Core Communication Interface for FPGAs  

Microsoft Academic Search

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

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

2002-01-01

281

Core Inflation  

Microsoft Academic Search

The Bank of Canada uses core CPI inflation, the year-over-year rate of change of the consumer price index excluding food, energy, and the effects of changes in indirect taxes, as the operational guide for monetary policy. In this report we study the concept and measurement of core or underlying inflation more generally by examining several alternative measures of core inflation,

Seamus Hogan; Marianne Johnson; Thérèse Laflèche

2001-01-01

282

Test infrastructure design for core-based system-on-chip under cycle-accurate thermal constraints  

Microsoft Academic Search

We present a thermal-aware test-access mechanism (TAM) design and test scheduling method for system-on-chip (SOC) integrated circuits. The proposed method uses cycle-accurate power profiles for thermal simulation; it also relies on test-set partitioning, test interleaving, and bandwidth matching. We use a computationally tractable thermal-cost model to ensure that temperature constraints are satisfied and the test application time is minimized. Simulation

Thomas Edison Yu; Tomokazu Yoneda; Krishnendu Chakrabarty; Hideo Fujiwara

2009-01-01

283

Promising core structure for nuclear receptor ligands: Design and synthesis of novel estrogen receptor ligands based on diphenylamine skeleton  

Microsoft Academic Search

Novel diphenylamine-type estrogen receptor ligands were designed and synthesized, and their biological activities were evaluated by means of binding assays for estrogen receptor-? and -? and cell proliferation assay using MCF-7 cells. Compounds 4f, 11b, 12c, and 8 showed moderate estrogenic activities. We propose that the diphenylamine skeleton may be a privileged structure for various nuclear receptor ligands, including RAR,

Kiminori Ohta; Yuki Chiba; Takumi Ogawa; Yasuyuki Endo

2008-01-01

284

Design of efficient dye-sensitized solar cells with patterned ZnO-ZnS core-shell nanowire array photoanodes.  

PubMed

The fabrication of photoanodes with a high light-harvesting ability, direct electron pathway and low exciton recombination is a key challenge in dye-sensitized solar cells (DSSCs) today. In this paper, large-scale patterned ZnO-ZnS core-shell nanowire arrays (NWAs) are designed and fabricated as such photoanodes for the fist time. By using the NWA photoanodes with a hexagonal symmetry and FTO-Pt cathodes with an Al reflecting layer, the resulting DSSCs demonstrate a maxiumum efficiency of 2.09%, which is an improvement of 140% compared to the reference cells with line symmetry and no reflecting layer. This improvement is attributed to the enhanced light-harvesting ability of the patterned NWAs, as well as to the remarkable double absorption caused by the Al reflecting layer. Additionally, the ZnO core provides a direct electron pathway and the ZnS shell simultaneously reduces exciton recombination. This study shows an effective method to improve the performance of DSSCs which could be extended to other nanodevices and nanosystems. PMID:24652390

Chen, Xiang; Bai, Zhiming; Yan, Xiaoqin; Yuan, Haoge; Zhang, Guangjie; Lin, Pei; Zhang, Zheng; Liu, Yichong; Zhang, Yue

2014-05-01

285

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

286

Development of innovative oil-core self-organized nanovesicles prepared with chitosan and lecithin using a 2(3) full-factorial design.  

PubMed

The aim of this study was to develop innovative nanosystems with isopropyl myristate as the oil core of self-assembly nanovesicles constituted of chitosan and lecithin using a 2(3) factorial design. The factors analyzed were chitosan (X1, levels 4 and 8 ?mg/ml), oil (X2, levels 10 and 20? mg/ml) and lecithin (X3, levels 4 and 8?mg/ml). The responses evaluated were diameter, zeta potential, pH, viscosity, and backscattering analysis. The bioavailability was evaluated after oral administration of clozapine free and nanoencapsulated in rats. The diameter ranged from 0.348 to 1.5?µm for F2 (X1, 4; X2, 10; X3, 8?mg/ml) and F7 (X1, 8; X2, 20; X3, 4 ?mg/ml), respectively. Laser diffractometry analysis revealed only one diameter population for all batches. Zeta potential was positive, being influenced by X1 and X2/X3 association. Viscosity values were dependent on the X1 and X2 concentrations used. A structure proposed for the nanosystem consists of chitosan forming the hydrophilic shell layer that protects the core comprised of lecithin and the hydrophobic groups of oil. The AUC0-? was almost 3 times higher with the clozapine nanoencapsuted in relation to free drug. It was developed a new nanosystem which is able of improving the absorption of drugs. PMID:23998248

Haas, Sandra Elisa; de Andrade, Cristiane; Sansone, Pedro Ernesto da Silva; Guterres, Silvia; Dalla Costa, Teresa

2014-11-01

287

Micro coring apparatus  

NASA Technical Reports Server (NTRS)

A micro-coring apparatus for lunar exploration applications, that is compatible with the other components of the Walking Mobile Platform, was designed. The primary purpose of core sampling is to gain an understanding of the geological composition and properties of the prescribed environment. This procedure has been used extensively for Earth studies and in limited applications during lunar explorations. The corer is described and analyzed for effectiveness.

Collins, David; Brooks, Marshall; Chen, Paul; Dwelle, Paul; Fischer, Ben

1989-01-01

288

ice core  

Microsoft Academic Search

Svalbard ice cores have not yet been fully exploited for studies of climate and environmental conditions. In one recently drilled ice core from Lomonosovfonna we have studied the methanesulphonic acid (MSA) records in relation to temperature and sea ice. During the present climatic conditions MSA appears to be negatively correlated with the sea ice conditions in the Barents Sea, and

Elisabeth Isaksson; Teija Kekonen; John Moore

289

Wireline sidewall coring  

SciTech Connect

In April 1989, Schlumberger Well Services, under contract to Fenix and Scisson of Nevada, Inc., ran a wireline sidewall coring machine in exploratory hole Ue4t at the Nevada Test Site for the Los Alamos National Laboratory. The sampling project goals were to recover material for geologic characterization and to determine the effectiveness of the tool for sampling various volcanic lithologies. If a wireline tool is found to be effective, fewer expensive continuously-cored holes will be needed. The Schlumberger Sidewall Coredriller has a maximum diameter of 5.25 inches and, with the gamma-ray unit included for stratigraphic correlation, is approximately 40 feet long. It weighs 850 pounds. All the downhole mechanical systems are hydraulic including the anchor shoe, the coring motor, the pressure on the bit and the core extraction system. Sonde functions are monitored and controlled at the surface. The tool is designed to run in fluid with the waterways in the diamond but creating circulation to keep the bit face clean. Up to 20 cores, measuring 0.91 inches in diameter by 2 inches long, can be recovered with each each. These cores are separated in the split-sleeve catcher tube by discs automatically inserted following each coring. 1 ref., 4 figs., 1 tab.

Hawkins, W.L.; Mathews, M.A. (Los Alamos National Lab., NM (USA)); Thompson, P.H. (Fenix and Scisson, Inc., Mercury, NV (USA)); Jenkins, K. (Schlumberger Well Services, Casper, WY (USA))

1989-01-01

290

Core-Noise  

NASA Technical Reports Server (NTRS)

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 the presentation cover: the SFW system level noise metrics for the 2015, 2020, and 2025 timeframes; the emerging importance of core noise and its relevance to the SFW Reduced-Noise-Aircraft Technical Challenge; the current research activities in the core-noise area, with some additional details given about the development of a high-fidelity combustion-noise prediction capability; the need for a core-noise diagnostic capability to generate benchmark data for validation of both high-fidelity work and improved models, as well as testing of future noise-reduction technologies; relevant existing core-noise tests using real engines and auxiliary power units; and examples of possible scenarios for a future diagnostic facility. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Noise-Aircraft Technical Challenge aims to enable concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical for enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor designs could increase the combustion-noise component. The trend towards high-power-density cores also means that the noise generated in the low-pressure turbine will likely increase. Consequently, the combined result from these emerging changes will be to elevate the overall importance of turbomachinery core noise, which will need to be addressed in order to meet future noise goals.

Hultgren, Lennart S.

2010-01-01

291

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

292

Core Noise - Increasing Importance  

NASA Technical Reports Server (NTRS)

This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduced-Perceived-Noise Technical Challenge; and the current research activities in the core-noise area, with additional details given about the development of a high-fidelity combustor-noise prediction capability as well as activities supporting the development of improved reduced-order, physics-based models for combustor-noise prediction. The need for benchmark data for validation of high-fidelity and modeling work and the value of a potential future diagnostic facility for testing of core-noise-reduction concepts are indicated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor designs could increase the combustion-noise component. The trend towards high-power-density cores also means that the noise generated in the low-pressure turbine will likely increase. Consequently, the combined result from these emerging changes will be to elevate the overall importance of turbomachinery core noise, which will need to be addressed in order to meet future noise goals.

Hultgren, Lennart S.

2011-01-01

293

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

294

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

295

Towards Evolvable IP Cores for FPGAs  

Microsoft Academic Search

Abstract The paper deals with a new approach,to the design of adaptive hardware,using common,Field Programmable Gate Arrays (FPGA). The ultimate aim is to develop evolvable IP (Intellectual Property) cores. The cores should be reused in the same way as ordinary IP cores are reused. In contrast to the conventional cores, the evolvable cores are able to perform autonomous,evolution of their

Lukás Sekanina

2003-01-01

296

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

297

An ultra-clean firn core from the Devon Island Ice Cap, Nunavut, Canada, retrieved using a titanium drill specially designed for trace element studies.  

PubMed

An electromechanical drill with titanium barrels was used to recover a 63.7 m long firn core from Devon Island Ice Cap, Nunavut, Canada, representing 155 years of precipitation. The core was processed and analysed at the Geological Survey of Canada by following strict clean procedures for measurements of Pb and Cd at concentrations at or below the pg g(-1) level. This paper describes the effectiveness of the titanium drill with respect to contamination during ice core retrieval and evaluates sample-processing procedures in laboratories. The results demonstrate that: (1) ice cores retrieved with this titanium drill are of excellent quality with metal contamination one to four orders of magnitude less than those retrieved with conventional drills; (2) the core cleaning and sampling protocols used were effective, contamination-free, and adequate for analysis of the metals (Pb and Cd) at low pg g(-1) levels; and (3) results from 489 firn core samples analysed in this study are comparable with published data from other sites in the Arctic, Greenland and the Antarctic. PMID:16528426

Zheng, J; Fisher, D; Blake, E; Hall, G; Vaive, J; Krachler, M; Zdanowicz, C; Lam, J; Lawson, G; Shotyk, W

2006-03-01

298

Simplified cut-core inductor  

NASA Technical Reports Server (NTRS)

Technical memorandum describes design of linear reactor fabricated from grain-oriented steel. It includes design charts and nomographs and illustrates design of grain-oriented inductor via seven-step example. Typical values of core inductance, operating frequency, and coil current (dc and ac) are given.

Mclyman, W. T.

1977-01-01

299

Saturation current spikes eliminated in saturable core transformers  

NASA Technical Reports Server (NTRS)

Unsaturating composite magnetic core transformer, consisting of two separate parallel cores designed so impending core saturation causes signal generation, terminates high current spike in converter primary circuit. Simplified waveform, demonstrates transformer effectiveness in eliminating current spikes.

Schwarz, F. C.

1971-01-01

300

Ethics CORE  

NSDL National Science Digital Library

The Ethics CORE Digital Library, funded by the National Science Foundation, "brings together information on best practices in research, ethics instruction and responding to ethical problems that arise in research and professional life." It's a remarkable site where visitors can make their way through ethics resources for dozens of different professions and activities. The Resources by Discipline area is a great place to start. Here you will find materials related to the biological sciences, business, computer & information science, along with 14 additional disciplines. The Current News area is a great place to learn about the latest updates from the field. Of note, these pieces can easily be used in the classroom or shared with colleagues. The dynamism of the site can be found at the Interact with Ethics CORE area. Active learning exercises can be found here, along with instructional materials and visitors' own lessons learned.

301

Core Noise Reduction  

NASA Technical Reports Server (NTRS)

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

Hultgren, Lennart S.

2011-01-01

302

Designed synthesis of SiO2/TiO2 core/shell structure as light scattering material for highly efficient dye-sensitized solar cells.  

PubMed

SiO2/TiO2 core/shell nanoparticles (STCS-NPs) with diameters of 110, 240, and 530 nm were fabricated to investigate the influence of the size and refractive index of light-scattering particles on light-scattering properties. The optical properties of STCS-NPs were evaluated and compared with SiO2-NPs and TiO2-NPs. The structure of STCS-NPs, consisting of a low refractive index core and high refractive index shell, provides efficient light scattering. The optimized anode film with STCS-NPs had ca. 20% improved power conversion efficiency (PCE). PMID:23635382

Son, Suim; Hwang, Sun Hye; Kim, Chanhoi; Yun, Ju Young; Jang, Jyongsik

2013-06-12

303

Curriculum Design, Development, and Implementation in an Era of Common Core State Standards. Summary Report of a Conference (Arlington, Virginia, August 1-3, 2010)  

ERIC Educational Resources Information Center

In June 2010, the National Governor's Association and the Council of Chief State School Officers published "Common Core State Standards" (CCSS) for K-12 mathematics. Forty-eight states collaborated in the development of CCSS and, to date, 34 states have officially adopted CCSS to replace existing state standards. CCSS presents an opportunity for…

Confrey, Jere; Krupa, Erin

2010-01-01

304

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

305

Fissioning Plasma Core Reactor  

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

306

How we test Siemens Embedded DRAM Cores  

Microsoft Academic Search

The techniques used to test Siemens Embedded DRAM Cores are described. Test Isolation and Design-For-Test logic is built in to the core interface, while external access and Algorithmic Pattern Generation are handled by a central Test Controller. All tests used for standard DRAM's can be applied to the DRAM cores, but only a subset of these are used for any

Roderick Mcconnell; Udo Möller; Detlev Richter

1998-01-01

307

Core temperature measurement in carbothermal reduction processes  

Microsoft Academic Search

An accurate temperature measurement of the core in carbothermal reduction processes, such as boron and silicon carbide manufacturing processes, is not only important from product quality viewpoint but also quite a challenging task. The core temperature in these processes ranges 2200 to 3000K. In this study, a device has been designed to measure the core temperature. Much attention has been

M. P. L. N. Rao; G. S. Gupta; P. Manjunath; S. Kumar; A. K. Suri; N. Krishnamurthy; C. Subramanian

2009-01-01

308

Simplified Model of Core Thermal Dilation.  

National Technical Information Service (NTIS)

A simple analytical model is developed of core radial expansion for a fast reactor using a limited-free-bow core restraint design. The model is restricted to those bowing regimes where the plane of above core load pads (ACLP) is compacted to the point whe...

T. J. Moran

1987-01-01

309

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

310

Uranium droplet core nuclear rocket  

NASA Technical Reports Server (NTRS)

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

Anghaie, Samim

1991-01-01

311

Baroplastic core-shell nanoparticles  

NASA Astrophysics Data System (ADS)

A novel class of baroplastic core-shell nanoparticles was designed based on the pressure-induced miscibility between a low Tg component core and a high Tg component shell and obtained by a two-stage miniemulsion polymerization technique. By changing the amount of surfactant and monomer feed ratio, the size and composition of core-shell nanoparticles were controlled and almost homogenous particles with very narrow particle size distribution were obtained in each synthetic step. Trilayerd core-shell nanoparticles, which have an additional inner-core, were also successfully synthesized by sequential addition of monomers. The baroplasticity of these core-shell nanoparticles was demonstrated by compression molding and characterized by SANS, DSC, and TEM. Transparent objects were molded at temperatures as low as 25 oC under 5000 psi pressure, and recycled up to 10 times, from poly(n-butyl acrylate)/polystyrene or poly(2-ethyl hexyl acrylate)/polystyrene systems. The particle size was found to play an important role to determine the optical and mechanical properties of the resulting product. By comparison with bilayered core-shell nanoparticles, improved mechanical properties were observed in trilayered systems due to the enlarged interface region. Finally, blend or hybrid baroplastic core-shell nanoparticles were prepared incorporating other polymer or inorganic nanoparticles.

Woog Ryu, Sang; Gonzalez, Juan; Acar, Metin; Mayes, Anne

2004-03-01

312

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

2013-08-14

313

Bottom-up design and synthesis of limit size lipid nanoparticle systems with aqueous and triglyceride cores using millisecond microfluidic mixing.  

PubMed

Limit size systems are defined as the smallest achievable aggregates compatible with the packing of the molecular constituents in a defined and energetically stable structure. Here we report the use of rapid microfluidic mixing for the controlled synthesis of two types of limit size lipid nanoparticle (LNP) systems, having either polar or nonpolar cores. Specifically, limit size LNP consisting of 1-palmitoyl, 2-oleoyl phosphatidylcholine (POPC), cholesterol and the triglyceride triolein were synthesized by mixing a stream of ethanol containing dissolved lipid with an aqueous stream, employing a staggered herringbone micromixer. Millisecond mixing of aqueous and ethanol streams at high flow rate ratios (FRR) was used to rapidly increase the polarity of the medium, driving bottom-up synthesis of limit size LNP systems by spontaneous assembly. For POPC/triolein systems the limit size structures consisted of a hydrophobic core of triolein surrounded by a monolayer of POPC where the diameter could be rationally engineered over the range 20-80 nm by varying the POPC/triolein ratio. In the case of POPC and POPC/cholesterol (55/45; mol/mol) the limit size systems achieved were bilayer vesicles of approximately 20 and 40 nm diameter, respectively. We further show that doxorubicin, a representative weak base drug, can be efficiently loaded and retained in limit size POPC LNP, establishing potential utility as drug delivery systems. To our knowledge this is the first report of stable triglyceride emulsions in the 20-50 nm size range, and the first time vesicular systems in the 20-50 nm size range have been generated by a scalable manufacturing method. These results establish microfluidic mixing as a powerful and general approach to access novel LNP systems, with both polar or nonpolar core structures, in the sub-100 nm size range. PMID:22268499

Zhigaltsev, Igor V; Belliveau, Nathan; Hafez, Ismail; Leung, Alex K K; Huft, Jens; Hansen, Carl; Cullis, Pieter R

2012-02-21

314

Acquisition of TMI2 core debris samples  

Microsoft Academic Search

Recently the first samples of material were obtained from the damaged TMI-2 reactor core. This paper reviews the design and operation of the specialized equipment used to acquire these samples. In addition to two unique core debris rubble bed samplers, a 14-m-long sampler deployment boom, radiation shielding, and sample casks were designed and fabricated for the task. Analysis of the

D. E. Owen; D. S. Fee; J. M. Bower

1983-01-01

315

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

316

Synthetic Core Promoters for Pichia pastoris.  

PubMed

Synthetic promoters are commonly used tools for circuit design or high level protein production. Promoter engineering efforts in yeasts, such as Saccharomyces cerevisiae and Pichia pastoris have mostly been focused on altering upstream regulatory sequences such as transcription factor binding sites. In higher eukaryotes synthetic core promoters, directly needed for transcription initiation by RNA Polymerase II, have been successfully designed. Here we report the first synthetic yeast core promoter for P. pastoris, based on natural yeast core promoters. Furthermore we used this synthetic core promoter sequence to engineer the core promoter of the natural AOX1 promoter, thereby creating a set of core promoters providing a range of different expression levels. As opposed to engineering strategies of the significantly longer entire promoter, such short core promoters can directly be added on a PCR primer facilitating library generation and are sufficient to obtain variable expression yields. PMID:24187969

Vogl, Thomas; Ruth, Claudia; Pitzer, Julia; Kickenweiz, Thomas; Glieder, Anton

2014-03-21

317

Design potential selective inhibitors for treating cancer by targeting the Src homology 2 (SH2) domain-containing phosphatase 2 (Shp2) with core hopping approach.  

PubMed

Due to the vital role in many cell regulatory processes, such as cell cycle control, survival and apoptosis, as well as growth and neurotransmitter signaling, Src homology 2 (SH2) domain-containing phosphatase 2(Shp2) has attracted considerable attention for developing drugs to treat cancers. In this study, by means of the powerful "core hopping" technique, a novel class of inhibitors was discovered based on the compound II-B08. It was observed by molecular dynamics simulations that these novel inhibitors not only possessed the same function as II-B08 did in inhibiting Shp2, but also had stronger binding to the receptor. It was further validated by the outcomes of their ADME (absorption, distribution, metabolism, and excretion) predictions that the new inhibitors hold high potential to become promising drug candidates for developing novel and powerful drugs for anticancer. Subsequently, in vitro evaluation of promising hits revealed a novel and selective inhibitor of Shp2. PMID:24364859

Duan, Yu-Qing; Ma, Ying; Wang, Xue-Jiao; Jin, Yuan-Yuan; Wang, Run-Ling; Dong, Wei-Li; Xu, Wei-Ren; Kong, De-Xin; Wang, Shu-Qing

2014-06-01

318

Diagnostic Performance of Combined Non-invasive Coronary Angiography and Myocardial Perfusion Imaging Using 320 Row Detector Computed Tomography: Design and Implementation of the CORE320 Multicenter, Multinational Diagnostic Study  

PubMed Central

Multi-detector coronary computed tomography angiography (CTA) is a promising modality for widespread clinical application because of its non-invasive nature and high diagnostic accuracy as found in previous studies using 64 to 320 simultaneous detector rows. It is, however, limited in its ability to detect myocardial ischemia. In this manuscript we describe the design of the CORE320 study (“Combined Coronary Atherosclerosis and Myocardial Perfusion Evaluation Using 320 Detector Row Computed Tomography”). This prospective, multicenter, multinational study is unique in that it is designed to assess the diagnostic performance of combined 320-row CTA and myocardial CT perfusion imaging (CTP) in comparison to the combination of invasive coronary angiography and single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The trial is being performed at 16 medical centers located in 8 countries worldwide. Computed tomography has the potential to assess both anatomy and physiology in a single imaging session. The co-primary aims of the CORE320 study is to define the per-patient diagnostic accuracy of the combination of coronary CTA and myocardial CTP to detect physiologically significant coronary artery disease compared to 1) the combination of conventional coronary angiography and SPECT-MPI and 2) conventional coronary angiography alone. If successful, the technology could revolutionize the management of patients with symptomatic CAD.

Vavere, Andrea L.; Simon, Gregory G.; George, Richard T.; Rochitte, Carlos E.; Arai, Andrew E.; Miller, Julie M.; Di Carli, Marcello; Zadeh, Armin A.; Dewey, Marc; Niinuma, Hiroyuki; Laham, Roger; Rybicki, Frank J.; Schuijf, Joanne D.; Paul, Narinder; Hoe, John; Kuribyashi, Sachio; Sakuma, Hajime; Nomura, Cesar; Yaw, Tan Swee; Kofoed, Klaus F.; Yoshioka, Kunihiro; Clouse, Melvin E.; Brinker, Jeffrey; Cox, Christopher; Lima, Joao AC

2013-01-01

319

Scaling OLTP applications on commodity multi-core platforms  

Microsoft Academic Search

Multi-core processor architectures can have significant performance advantage over traditional single core designs, which are limited by power and processor complexity. Predictions based on Moore's Law state that a processor chip may accommodate thousands of cores in 5-10 years. Can software scale with the number of cores and achieve the performance potential? This paper uses two OLTP (online transaction processing)

Yan Cui; Yu Chen; Yuanchun Shi

2010-01-01

320

Core Recursive Hierarchical Image Segmentation  

NASA Technical Reports Server (NTRS)

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

Tilton, James

2011-01-01

321

CORE Operations Center  

NASA Technical Reports Server (NTRS)

This report gives an overall view of the CORE program at Goddard Space Flight Center (GSFC). It summarizes the different CORE sessions and gives information about the technical staff. The outlook summarizes the evolution of the different CORE programs.

Thomas, Cynthia; Vandenberg, Nancy

1999-01-01

322

The IS Core: An Integration of the Core IS Courses  

ERIC Educational Resources Information Center

This paper describes an innovative, integrated implementation of the core Information Systems courses. While the published IS curriculum provides standards on course "content", it gives little direction on the "implementation" of the courses. At Brigham Young University, we have reengineered the traditional topics of analysis, database, design

Albrecht, Conan C.; Romney, Marshall; Lowry, Paul Benjamin; Moody, Greg

2009-01-01

323

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

324

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

325

Symmetrical Core Improves Micro-Fluxgate Sensors  

Microsoft Academic Search

Microfluxgate sensor with flat coil and double-sided symmetrical core has significantlyimproved parameters over the original asymmetric single-sided core design. The magneticcircuit of the new sensor is more closed and so the core is deeper saturated. The sensorhysteresis was decreased from 30 T to 2.5 T (for full range). Noise level was decreasedfrom 242 nT to 27 nT rms (0.1 mHz

A. Tipek; M. Ishida; S. Kawahito

326

Core-core and core-valence correlation  

NASA Technical Reports Server (NTRS)

The effect of (1s) core correlation on properties and energy separations was analyzed using full configuration-interaction (FCI) calculations. The Be 1 S - 1 P, the C 3 P - 5 S and CH+ 1 Sigma + or - 1 Pi separations, and CH+ spectroscopic constants, dipole moment and 1 Sigma + - 1 Pi transition dipole moment were studied. The results of the FCI calculations are compared to those obtained using approximate methods. In addition, the generation of atomic natural orbital (ANO) basis sets, as a method for contracting a primitive basis set for both valence and core correlation, is discussed. When both core-core and core-valence correlation are included in the calculation, no suitable truncated CI approach consistently reproduces the FCI, and contraction of the basis set is very difficult. If the (nearly constant) core-core correlation is eliminated, and only the core-valence correlation is included, CASSCF/MRCI approached reproduce the FCI results and basis set contraction is significantly easier.

Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

1988-01-01

327

Foam core materials for structural sandwich panels  

Microsoft Academic Search

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

Huang Jongshin

1991-01-01

328

Velocity-Controlled Magnetic Bearings with Solid Cores  

NASA Technical Reports Server (NTRS)

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

Chen, H. Ming; Walton, James

1996-01-01

329

Long Valley Coring Project, Inyo County, California, 1998, preliminary stratigraphy and images of recovered core  

USGS Publications Warehouse

Phase III of the Long Valley Exploratory Well, the Long Valley Coring Project, obtained continuous core between the depths of 7,180 and 9,831 ft (2,188 to 2,996 meters) during the summer of 1998. This report contains a compendium of information designed to facilitate post-drilling research focussed on the study of the core. Included are a preliminary stratigraphic column compiled primarily from field observations and a general description of well lithology for the Phase III drilling interval. Also included are high-resolution digital photographs of every core box (10 feet per box) as well as scanned images of pieces of recovered core. The user can easily move from the stratigraphic column to corresponding core box photographs for any depth. From there, compressed, "unrolled" images of the individual core pieces (core scans) can be accessed. Those interested in higher-resolution core scans can go to archive CD-ROMs stored at a number of locations specified herein. All core is stored at the USGS Core Research Center in Denver, Colorado where it is available to researchers following the protocol described in this report. Preliminary examination of core provided by this report and the archive CD-ROMs should assist researchers in narrowing their choices when requesting core splits.

Sackett, Penelope C.; McConnell, Vicki S.; Roach, Angela L.; Priest, Susan S.; Sass, John H.

1999-01-01

330

Compilation Techniques for Core Plus FPGA Systems  

NASA Technical Reports Server (NTRS)

The overall system architecture targeted in this study is a core-plus-fpga design, which is composed of a core VLIW DSP with on-chip memory and a set of special-purpose functional units implemented using FPGAs. A figure is given which shows the overall organization of the core-plus-fpga system. It is important to note that this architecture is relatively simple in concept and can be built from off-the-shelf commercial components, such as one of the Texas Instruments 320C6x family of DSPs for the core processor.

Conte, Tom

2001-01-01

331

Academic Rigor: The Core of the Core  

ERIC Educational Resources Information Center

Some educators see the Common Core State Standards as reason for stress, most recognize the positive possibilities associated with them and are willing to make the professional commitment to implementing them so that academic rigor for all students will increase. But business leaders, parents, and the authors of the Common Core are not the only…

Brunner, Judy

2013-01-01

332

Symmetrical core improves micro-fluxgate sensors  

Microsoft Academic Search

New micro-fluxgate sensor with flat excitation and sensing coils and double-sided symmetrical core has significantly improved parameters over the original asymmetric single-sided core design. The main advantage of the new design is that the demagnetization with respect to the excitation field is much lower than demagnetization with respect to the external measured field. The magnetic circuit of the new sensor

P. Ripka; S. O. Choi; A. Tipek; S. Kawahito; M. Ishida

2001-01-01

333

Design of meso-TiO2@MnO(x)-CeO(x)/CNTs with a core-shell structure as DeNO(x) 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

2013-10-21

334

Droplet Core Nuclear Rocket (DCNR)  

NASA Technical Reports Server (NTRS)

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

Anghaie, Samim

1991-01-01

335

The Core Curriculum.  

ERIC Educational Resources Information Center

This keynote address for the workshop on "The Integrated Core Curriculum: Alternative Approaches" held in March 1977 summarizes the objectives and historical development of the core curriculum in library science. (MBR)

Asheim, Lester E.

1978-01-01

336

Army's Core Competencies.  

National Technical Information Service (NTIS)

In October 2011, the United States Army published doctrine espousing its newest core competencies: Combined Arms Maneuver (CAM) and Wide Area Security (WAS). The Army's use of the term 'core competencies' introduced questions of validity since the Army fa...

R. E. Dunning

2013-01-01

337

Transformer Core Clamp.  

National Technical Information Service (NTIS)

This report describes a transformer core clamp that increases both the clamping force applied to a center leg of the transformer core and the shock resistance of the transformer core. The clamp is constructed with opposed clamp plates on the outward facin...

B. Allen N. Williams

1980-01-01

338

Sidewall core gun  

Microsoft Academic Search

An apparatus is described for taking core samples from the sidewall of a borehole in a well, the apparatus comprising: a string of drill pipe; at least one gun housing connected to the downhole end of the drill string; at least one coring bullet radially disposed within the gun housing, the coring bullet arranged for securing formation samples from the

E. A. Jr. Colle; D. N. Jr. Yates; E. F. Brieger

1986-01-01

339

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

340

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

341

Banded transformer cores  

NASA Technical Reports Server (NTRS)

A banded transformer core formed by positioning a pair of mated, similar core halves on a supporting pedestal. The core halves are encircled with a strap, selectively applying tension whereby a compressive force is applied to the core edge for reducing the innate air gap. A dc magnetic field is employed in supporting the core halves during initial phases of the banding operation, while an ac magnetic field subsequently is employed for detecting dimension changes occurring in the air gaps as tension is applied to the strap.

Mclyman, C. W. T. (inventor)

1974-01-01

342

Concept of a core cooling system and experiments performed  

Microsoft Academic Search

One of the problems which must be solved in severe accidents is the melt-concrete interaction which does occur when the core debris penetrates the lower pressure vessel head and contacts the basement. To prevent these accident consequences, a core catcher concept is proposed to be integrated into a new pressurized-water reactor design. The core catcher achieves coolability by spreading and

H. Alsmeyer; W. Tromm

1995-01-01

343

Damage tolerance of a composite sandwich with interleaved foam core  

Microsoft Academic Search

A composite sandwich panel consisting of carbon fiber-reinforced plastic (CFRP) skins and a syntactic foam core was selected as an appropriate structural concept for the design of wind tunnel compressor blades. Interleaving of the core with tough interlayers was done to prevent core cracking and to improve damage tolerance of the sandwich. Simply supported sandwich beam specimens were subjected to

Ori Ishai; Clement Hiel; T Kevin O'Brien

1992-01-01

344

Institutional Management of Core Facilities during Challenging Financial Times  

PubMed Central

The economic downturn is likely to have lasting effects on institutions of higher education, prioritizing proactive institutional leadership and planning. Although by design, core research facilities are more efficient and effective than supporting individual pieces of research equipment, cores can have significant underlying financial requirements and challenges. This paper explores several possible institutional approaches to managing core facilities during challenging financial times.

Haley, Rand

2011-01-01

345

Estimate of Core Shroud Temperature by means of a CFD Model of Core Bypass  

Microsoft Academic Search

A power uprate of Forsmark's Unit 3 from 109 % to 125 % will be implemented during the 2010 refuelling outage. This implies an increase in gamma heating of the core shroud which could lead to temperatures higher than the design thickness-mean temperature, 300°C, according to ASME regulations. The CFX 5 model to estimate the core shroud temperature distribution consists

Hernan Tinoco; Stefan Ahlinder; Peter Hedberg

2008-01-01

346

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

ERIC Educational Resources Information Center

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

Achieve, Inc., 2010

2010-01-01

347

Comparing the Common Core State Standards and Singapore's Mathematics Syllabus. Achieving the Common Core  

ERIC Educational Resources Information Center

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

Achieve, Inc., 2010

2010-01-01

348

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

349

Multi-Core Processor Memory Contention Benchmark Analysis Case Study  

NASA Technical Reports Server (NTRS)

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

Simon, Tyler; McGalliard, James

2009-01-01

350

ON CONNECTING CORES TO PACKET SWITCHED ON-CHIP NETWORKS: A CASE STUDY WITH MICROBLAZE PROCESSOR CORES  

Microsoft Academic Search

The idea of using on chip packet switched networks for interconnecting a large number of IP cores is very practical for designing complex SoCs since it gives possibility of not only reusing IP cores but also the interconnection infrastructure. However, the real effort and time in using these Networks on Chip (NoC) goes in developing interfaces for connecting cores to

Rickard Holsmark; Alf Johansson; Shashi Kumar

351

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

352

Core-Core and Core-Valence Correlation.  

National Technical Information Service (NTIS)

The effect of (1s) core correlation on properties and energy separations was analyzed using full configuration-interaction (FCI) calculations. The Be 1 S - 1 P, the C 3 P - 5 S and CH+ 1 Sigma + or - 1 Pi separations, and CH+ spectroscopic constants, dipo...

C. W. Bauschlicher S. R. Langhoff P. R. Taylor

1988-01-01

353

Core-Cutoff Tool  

NASA Technical Reports Server (NTRS)

A tool makes a cut perpendicular to the cylindrical axis of a core hole at a predetermined depth to free the core at that depth. The tool does not damage the surrounding material from which the core was cut, and it operates within the core-hole kerf. Coring usually begins with use of a hole saw or a hollow cylindrical abrasive cutting tool to make an annular hole that leaves the core (sometimes called the plug ) in place. In this approach to coring as practiced heretofore, the core is removed forcibly in a manner chosen to shear the core, preferably at or near the greatest depth of the core hole. Unfortunately, such forcible removal often damages both the core and the surrounding material (see Figure 1). In an alternative prior approach, especially applicable to toxic or fragile material, a core is formed and freed by means of milling operations that generate much material waste. In contrast, the present tool eliminates the damage associated with the hole-saw approach and reduces the extent of milling operations (and, hence, reduces the waste) associated with the milling approach. The present tool (see Figure 2) includes an inner sleeve and an outer sleeve and resembles the hollow cylindrical tool used to cut the core hole. The sleeves are thin enough that this tool fits within the kerf of the core hole. The inner sleeve is attached to a shaft that, in turn, can be attached to a drill motor or handle for turning the tool. This tool also includes a cutting wire attached to the distal ends of both sleeves. The cutting wire is long enough that with sufficient relative rotation of the inner and outer sleeves, the wire can cut all the way to the center of the core. The tool is inserted in the kerf until its distal end is seated at the full depth. The inner sleeve is then turned. During turning, frictional drag on the outer core pulls the cutting wire into contact with the core. The cutting force of the wire against the core increases with the tension in the wire and, hence, with the frictional drag acting on the outer sleeve. As the wire cuts toward the center of the core, the inner sleeve rotates farther with respect to the outer sleeve. Once the wire has cut to the center of the core, the tool and the core can be removed from the hole. The proper choice of cutting wire depends on the properties of the core material. For a sufficiently soft core material, a nonmetallic monofilament can be used. For a rubber-like core material, a metal wire can be used. For a harder core material, it is necessary to use an abrasive wire, and the efficiency of the tool can be increased greatly by vacuuming away the particles generated during cutting. For a core material that can readily be melted or otherwise cut by use of heat, it could be preferable to use an electrically heated cutting wire. In such a case, electric current can be supplied to the cutting wire, from an electrically isolated source, via rotating contact rings mounted on the sleeves.

Gheen, Darrell

2007-01-01

354

TMI2 core bore gamma ray spectroscopy measurements  

Microsoft Academic Search

Gamma spectroscopy measurements were performed on TMI-2 core samples to evaluate the distribution of gamma-ray-emitting radionuclides, structural materials (⁶°Co), and uranium fuel (¹⁴⁴Ce) in the lower portion of the reactor core. A core boring machines, similar in design to the boring machines employed to extract geological core samples, was used during July and August, 1986, to drill through the entire

C. V. McIsaac; D. W. Akers

1988-01-01

355

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 SiO?/Au/N-doped TiO? 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

2013-08-20

356

Core melt experiment series in LOFT  

SciTech Connect

LOFT is being considered for future experiments involving core decomposition and migration because of the renewed NRC interest in Class 9 accidents following the TMI-2 event and because LOFT has unique capabilities for conducting this type experiment. A set of fuel damage experiments designated L8, L12 and L17 have evolved from the preliminary planning as follows: L8 allows center fuel bundle damage to occur within the removal capabilities of the existing fuel removal equipment; L12 allows entire core damage and decomposition to occur within the core boundaries; and L17 allows the decomposed core to migrate and erode the core support structures, reactor vessel, containment structure and containment substratum.

Russell, M.L.

1980-01-01

357

Achieving Micelle Control through Core Crystallinity  

PubMed Central

We have designed a pathway for controlling the critical micelle concentration and micelle size of polyester-based systems. This was achieved by creating an array of different copolymers with semicrystalline or amorphous hydrophobic blocks. The hydrophobic block was constructed through ring-opening polymerization of ?-caprolactone, l-lactide, and ?-decalactone, either as homopolymers or random copolymers, using PEG as both the initiator and the hydrophilic block. Micelles formed with amorphous cores exhibited considerably higher critical micelle concentrations than those with semicrystalline cores. Micelles with amorphous cores also became larger in size with an increased molecular weight of the hydrophobic bock, in contrast to micelles with semicrystalline cores, which displayed the opposite behavior. Hence, core crystallinity was found to be a potent tool for tailoring micelle properties and thereby facilitating the optimization of drug delivery systems. The introduction of PEG-P?DL also proved to be a valuable asset in the tuning of micelle properties.

2013-01-01

358

Gfr Core Neutronics Studies at CEA  

NASA Astrophysics Data System (ADS)

The Gas cooled Fast Reactor (GFR) is a high priority in the CEA R&D program on Future Nuclear Energy Systems. After preliminary neutronics and thermo-aerolic studies, a first He-cooled 2400MWth core design based on a series of carbide CERCER plates arranged in an hexagonal wrapper were selected. Although GFR subassembly and core design studies are still at an early stage of development, it is nonetheless possible to identify a number of nuclear data needs that could have some impact on the actual design: new materials, decay heat contributors….

Bosq, J. C.; Brun-Magaud, V.; Rimpault, G.; Tommasi, J.; Conti, A.; Garnier, J. C.

2006-04-01

359

17 CFR 38.3 - Procedures for designation.  

Code of Federal Regulations, 2010 CFR

...b) of the Act, the core principles for operation of section 5...designation criterion or core principle (final, executed copies...document describing, with specificity, the manner in which the...designation criterion and core principle (a regulatory chart);...

2009-04-01

360

Magnetic suspension using high temperature superconducting cores  

NASA Technical Reports Server (NTRS)

The development of YBCO high temperature superconductors, in wire and tape forms, is rapidly approaching the point where the bulk transport current density j vs magnetic field H characteristics with liquid nitrogen cooling will enable its use in model cores. On the other hand, BSCCO high temperature superconductor in wire form has poor j-H characteristics at 77 K today, although with liquid helium or hydrogen cooling, it appears to be superior to NbTi superconductor. Since liquid nitrogen cooling is approx. 100 times cheaper than liquid helium cooling, the use of YBCO is very attractive for use in magnetic suspension. The design is discussed of a model core to accommodate lift and drag loads up to 6000 and 3000 N respectively. A comparison is made between the design performance of a liquid helium cooled NbTi (or BSCCO) superconducting core and a liquid nitrogen cooled YBCO superconducting core.

Scurlock, R. G.

1992-01-01

361

The core paradox.  

NASA Technical Reports Server (NTRS)

Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.

Kennedy, G. C.; Higgins, G. H.

1973-01-01

362

Q in Earth's Core  

Microsoft Academic Search

Observations of high frequency PKnKP waves, multiply reflected by the underside of the core-mantle boundary, place a lower bound of 10,000 on the QK of the outer core. Hence, for most applications QK of the outer core can be assumed to be infinite, consistent with the expected behavior of a low viscosity fluid. Observations of high (>1 Hz) frequency PKPPKP

V. F. Cormier

2003-01-01

363

Core Research Center  

USGS Publications Warehouse

The Core Research Center (CRC) of the U.S. Geological Survey (USGS), located at the Denver Federal Center in Lakewood, Colo., currently houses rock core from more than 8,500 boreholes representing about 1.7 million feet of rock core from 35 States and cuttings from 54,000 boreholes representing 238 million feet of drilling in 28 States. Although most of the boreholes are located in the Rocky Mountain region, the geologic and geographic diversity of samples have helped the CRC become one of the largest and most heavily used public core repositories in the United States. Many of the boreholes represented in the collection were drilled for energy and mineral exploration, and many of the cores and cuttings were donated to the CRC by private companies in these industries. Some cores and cuttings were collected by the USGS along with other government agencies. Approximately one-half of the cores are slabbed and photographed. More than 18,000 thin sections and a large volume of analytical data from the cores and cuttings are also accessible. A growing collection of digital images of the cores are also becoming available on the CRC Web site Internet http://geology.cr.usgs.gov/crc/.

Hicks, Joshua; Adrian, Betty

2009-01-01

364

AN Core Analysis  

NASA Astrophysics Data System (ADS)

Several alternative approximations of neutron transport have been proposed in years to move around the known limitations imposed by neutron diffusion in the modeling of nuclear cores. However, only a few complied with the industrial requirements of fast numerical computation, concentrating more on physical accuracy. In this work, the AN transport methodology is discussed with particular interest in core performance calculations. The implementation of the methodology in full core codes is discussed with particular attention to numerical issues and to the integration within the entire simulation process. Finally, first results from core studies in AN transport are analyzed in detail and compared to standard results of neutron diffusion.

Barbarino, Andrea; Tomatis, Daniele

2014-06-01

365

Ice Core Facility  

NASA Astrophysics Data System (ADS)

To support its program of studying ice cores taken from the Greenland, Antarctic and midlatitude ice sheets, the Division of Polar Programs of the National Science Foundation is soliciting proposals for operating its ice core curatorial facility.NSF's current ice core repository is at the State University of New York at Buffalo, where it has been operated under annual contract since 1975. Beginning in Fiscal Year 1991, whoever manages the NSF facility, now to be called the U.S. Ice Core Repository, will do it under a 5-year cooperative agreement.

366

Adaptive core simulation  

NASA Astrophysics Data System (ADS)

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

Abdel-Khalik, Hany Samy

367

17 CFR 38.900 - Core Principle 17.  

Code of Federal Regulations, 2013 CFR

...COMMODITY FUTURES TRADING COMMISSION DESIGNATED CONTRACT MARKETS Composition of Governing Boards of Contract Markets § 38.900 Core Principle 17. The governance arrangements of the board of trade shall be designed to permit consideration of...

2013-04-01

368

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

369

Pulse Transformer Design Study.  

National Technical Information Service (NTIS)

This final report describes the design, development of fabrication techniques, fabrication, and testing of two uniform field, air core pulse transformers. The described transformer design minimizes the volume of dielectric material, which provides turn-to...

H. Aslin

1977-01-01

370

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

371

Modular core holder  

SciTech Connect

This patent describes a modular core holder. It comprises: a sleeve, forming an internal cavity for receiving a core. The sleeve including segments; support means, overlying the sleeve, for supporting the sleeve; and access means, positioned between at least two of the segments of the sleeve, for allowing measurement of conditions within the internal cavity.

Mueller, J.; Cole, C.W.; Hamid, S.; Lucas, J.K.

1991-03-05

372

Reading Antarctica's Rock Cores  

NSDL National Science Digital Library

In this activity, students learn about the tools and methods paleoclimatologists use to reconstruct past climates. In constructing sediment cores themselves, students will achieve a very good understanding of the sedimentological interpretation of past climates that scientists can draw from cores.

Dahlman, Luann; Andrill

373

TMI-2 core damage  

SciTech Connect

On March 28, 1979, the Unit 2 reactor at Three Mile Island (TMI) underwent an accident that resulted in severe damage to the reactor's core. A core damage examination program is essential to understanding the unique conditions and for developing work plans and tools in advance of each portion of the reactor disassembly /defueling effort. To characterize the conditions, the reactor vessel was divided into five regions requiring varied approaches to defueling, because each contains a unique configuration and formation: (1) upper core region, (2) mid-core region, (3) lower core region, (4) lower core support assembly region, and (5) lower heat region. The original core inventory included approx. 93,000 kg of fuel and 35,000 kg of structural and neutron absorber material for a total of 128,250 kg. Assuming that 90% of the hydrogen generated during the accident was due to reduction of the coolant and accounting for portions of the upper plenum structure that melted, the total postaccident core material comes to approx. 131,850 kg. As of January 9, 1987, 29,000 kg of the material had been defueled.

Eidam, G.R.; Worku, G.

1987-01-01

374

TMI2 core damage  

Microsoft Academic Search

On March 28, 1979, the Unit 2 reactor at Three Mile Island (TMI) underwent an accident that resulted in severe damage to the reactor's core. A core damage examination program is essential to understanding the unique conditions and for developing work plans and tools in advance of each portion of the reactor disassembly \\/defueling effort. To characterize the conditions, the

G. R. Eidam; G. Worku

1987-01-01

375

CORE Operation Center Report  

NASA Technical Reports Server (NTRS)

This report gives a synopsis of the activities of the CORE (continuous observations of the rotation of the Earth) Operating Center from March 1999 to December 2000. The report forecasts activities planned for the year 2001. The outlook summarizes the evolution of the different CORE programs.

Thomas, Cynthia C.

2001-01-01

376

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

377

NSDL Math Common Core  

NSDL National Science Digital Library

The NSDL Math Common Core collection provides quick and easy access to high-quality math resources that have been related to one or more standard statements within the Math Common Core. These resources are selected from the larger NSDL collection and other trusted providers, and organized by grade level and domain area.

2010-08-10

378

Initial Core Load Report.  

National Technical Information Service (NTIS)

The LOFT initial core load was completed September 23, 1977 using the method of Reference 3 to monitor reactivity. No significant problems were encountered. The Keff indicated throughout core load was approximately 3 to 6% lower than predicted and more th...

J. W. Cannon A. V. Briscoe W. R. Carpenter D. W. Knight W. Serrano

1978-01-01

379

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

380

Core Component Pot.  

National Technical Information Service (NTIS)

The core component pot is an open top vessel used to hold both new and irradiated core components for storage in the IDS and for holding the components submerged in sodium while being transported inside CLEM. The top of the CCP is equipped with a grapple ...

R. L. Martin R. P. Omberg

1975-01-01

381

Lunar Core and Tides  

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

382

Core Compactness of Progenitors  

NASA Astrophysics Data System (ADS)

The compactness of the core of a pre-supernova star is one of the important unexplored issues in progenitor evolution. Recent studies have found the core compactness to be varying non-monotonically as a function of ZAMS mass. In this work we have calculated a large grid of 1D full stellar and naked C/O core models using the implicit hydrodynamic code KEPLER and the open source stellar evolution code MESA, in order to gain a better insight in core compactness' dependence on the stellar mass and convection physics. We find the complicated evolution during C, O and Si burning phases act as the main cause of the non-monotonic variation of compactness, and the whole compactness curve as a function of mass to be quite dependent on the treatment of semiconvection. We also conclude that the C/O core mass is the main discriminant of pre-supernova structure.

Sukhbold, Tuguldur; Woosley, S. E.; Paxton, B.; Heger, A.

2013-04-01

383

Core Compactness of Progenitors  

NASA Astrophysics Data System (ADS)

The compactness of the core of a pre-supernova star is one of the important unexplored issues in progenitor evolution. Recent studies have found the core compactness to be varying non-monotonically as a function of ZAMS mass. In this work we have calculated a large grid of 1D full stellar and naked C/O core models using the implicit hydrodynamic code KEPLER and the open source stellar evolution code MESA, in order to gain a better insight in core compactness' dependence on the stellar mass and convection physics. We find the complicated evolution during C burning acts as the main cause of the non-monotonic variation of compactness, and the whole compactness curve as a function of mass to be quite dependent on the treatment of semiconvection. We also conclude that the C/O core mass is the main discriminant of pre-supernova structure.

Sukhbold, Tuguldur; Woosley, S. E.; Paxton, B.; Heger, A.

2013-01-01

384

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

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

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

385

Evolution of prestellar cores  

NASA Astrophysics Data System (ADS)

In this thesis I re-analyse the SCUBA archive data for the L1688 main cloud of Ophiuchus, incorporating all available scan-map and jiggle-map data. I create a new core mass function (CMF) for L1688 using updated values for the distance to this region, as well as new estimates for the temperatures and masses of the cores. I show that the CMF for LI688 is consistent with a three part power-law, with slopes the same as those seen in the stellar IMF. The deeper maps allows the discovery of a turnover in the CMF at 0.7A/, which shows that the core mass function appears to mimic the stellar initial mass function. This concordance is indicative that the stellar IMF is determined at the prestellar core phase. I also present HCO* (J=4 > 3) spectral line observations from HARP on the JCMT. Data are presented for 59 of the prestellar cores mapped using SCUBA. Using these data. I present a proposed evolutionary diagram for prestellar cores in the form of a radius-mass plot. I hypothesise that a core is formed in the low-mass, low-radius region of the plot. It then accretes quasi-statically, increasing in both mass and radius. When it crosses the limit of gravitational instability it begins to collapse, decreasing in radius, towards the region of the diagram where protostellar cores are seen. My predictions are borne out when I plot the collapsing cores on this diagram. I outline an analytical model, created by Whitworth & Ward-Thompson (2001), describing the collapse of a starless core with a Plummer-like density profile. I describe my addition of a simple radiative transfer code, which allows simulated spectral line profiles to be created for such cores. The model is shown to be consistent with previous models, and with the observed physical properties of prestellar cores. This model is applied to 20 of the spectral line profiles from the HCO+ (J=4 + 3) data. These 20 modelled cores are placed onto the proposed evolutionary diagram. Their modelled physical states are found to be consistent with the proposed evolutionary track. In conjunction with the SCUBA and HARP data, these fits allow a potential timeline for the LI688 cloud to be established for the first time.

Simpson, Robert J.

386

Design of hierarchical WDM networks  

Microsoft Academic Search

Hierarchical (multi-core) Wavelength Division Multiplexing (WDM) networks present a challenging design problem to the network designer who wishes to establish all-optical circuits end-to-end and across multiple network cores. Due to the nature of the hierarchical structure and its traffi distribution, it is likely that the inner core requires more capacity when compared to the capacity required by the metro cores,

Miguel Razo; Shreejith Billenahalli; Wanjun Huang; Arularasi Sivasankaran; Limin Tang; Hars Vardhan; Marco Tacca; Andrea Fumagalli; Paolo Monti; Young Lee; Xinchao Liu; Zhicheng Sui

2009-01-01

387

Multiple Core Galaxies  

NASA Technical Reports Server (NTRS)

Nuclei of galaxies often show complicated density structures and perplexing kinematic signatures. In the past we have reported numerical experiments indicating a natural tendency for galaxies to show nuclei offset with respect to nearby isophotes and for the nucleus to have a radial velocity different from the galaxy's systemic velocity. Other experiments show normal mode oscillations in galaxies with large amplitudes. These oscillations do not damp appreciably over a Hubble time. The common thread running through all these is that galaxies often show evidence of ringing, bouncing, or sloshing around in unexpected ways, even though they have not been disturbed by any external event. Recent observational evidence shows yet another phenomenon indicating the dynamical complexity of central regions of galaxies: multiple cores (M31, Markarian 315 and 463 for example). These systems can hardly be static. We noted long-lived multiple core systems in galaxies in numerical experiments some years ago, and we have more recently followed up with a series of experiments on multiple core galaxies, starting with two cores. The relevant parameters are the energy in the orbiting clumps, their relative.masses, the (local) strength of the potential well representing the parent galaxy, and the number of cores. We have studied the dependence of the merger rates and the nature of the final merger product on these parameters. Individual cores survive much longer in stronger background potentials. Cores can survive for a substantial fraction of a Hubble time if they travel on reasonable orbits.

Miller, R.H.; Morrison, David (Technical Monitor)

1994-01-01

388

Development of New IP Cores for Spacecraft Avionics  

NASA Astrophysics Data System (ADS)

The GRLIB IP library is an integrated set of reusable IP cores, designed for system-on-chip (SOC) development. The IP cores are centered around a common on-chip bus, and use a coherent method for simulation and synthesis. The library is vendor independent, with support for different CAD tools and target technologies. The success of any IP core library is highly dependent on the constantly increasing number of IP cores and the improvement of existing IP cores. This paper will cover both these aspects, presenting some new developments as well as some improvements of existing items.

Isomäi, M.; Ekergarn, J.; Hjorth, M.; Wessman, N.-J.; Habinc, S.

2010-08-01

389

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

390

A structured and scalable mechanism for test access to embedded reusable cores  

Microsoft Academic Search

The main objective of core-based IC design is improvement of design efficiency and time-to-market. In order to prevent test development from becoming the bottleneck in the entire development trajectory, reuse of pre-computed tests for the reusable pre-designed cores is mandatory. The core user is responsible for translating the test at core level into a test at chip level. A standardized

Erik Jan Marinissen; Robert G. J. Arendsen; Gerard Bos; Hans Dingemanse; Maurice Lousberg; Clemens Wouters

1998-01-01

391

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.

392

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

393

Midland Core Repository  

SciTech Connect

This report summarizes activities for this quarter in one table. Industrial users of this repository viewed and/or checked out 163 boxes of drill cores and cuttings samples from 18 wells during the quarter.

Tyler, Noel

2000-08-14

394

Core formation in asteroids  

NASA Technical Reports Server (NTRS)

The chemical and physical aspects of metal segregation in asteroids are considered. Evidence for the existence of metallic cores in asteroids, meteorite parent bodies, and planetesimals and for the amount of melting required to form cores is reviewed, and the physics of metal segregation is discussed. These considerations lead to the conclusion that about 50 percent of melting is required for metal to drain away and form a core. It is pointed out that such high amounts of melting were not always attained in asteroids, indicating that many asteroids might consist of partially differentiated silicates and metallic masses that did not segregate to a core. It is suggested that S asteroids might represent such partially differentiated bodies.

Taylor, G. J.

1992-01-01

395

Core Manager: Ellen Sisk  

NSDL National Science Digital Library

This is a PDF interview, PowerPoint slide set, and webpage biography of a core manager, detailing the importance of a lab manager to oversee the complex workings of DNA sequencing machines for an entire company.

2012-05-02

396

Core flow experiment protocol  

SciTech Connect

This letter report describes the current status of the core flow through apparatus and describes the protocol and test matrix to be followed during the initial experimental stage of radionuclide transport studies in the Integrated Testing task.

Viani, B.E.; Martin, S.I.

1997-12-01

397

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...

398

INTEGRAL core programme  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

399

Core Noise - Increasing Importance.  

National Technical Information Service (NTIS)

This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentat...

L. S. Hultgren

2011-01-01

400

Biospecimen Core Resource  

Cancer.gov

The Cancer Genome Atlas (TCGA) Biospecimen Core Resource centralized laboratory reviews and processes blood and tissue samples and their associated data using optimized standard operating procedures for the entire TCGA Research Network.

401

Emergency core cooling system  

DOEpatents

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

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

1983-01-01

402

Scoring Dawg Core Breakoff and Retention Mechanism  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

403

CFD Analysis of Core Bypass Phenomena  

SciTech Connect

The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the sector grid can be set as a symmetry boundary

Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

2010-03-01

404

CFD Analysis of Core Bypass Phenomena  

SciTech Connect

The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the one-twelfth grid can be set as a symmetry boundary

Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

2009-11-01

405

Industrial Technology Core (IT Core) Guide  

NSDL National Science Digital Library

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

2009-10-01

406

Q in Earth's Core  

NASA Astrophysics Data System (ADS)

Observations of high frequency PKnKP waves, multiply reflected by the underside of the core-mantle boundary, place a lower bound of 10,000 on the QK of the outer core. Hence, for most applications QK of the outer core can be assumed to be infinite, consistent with the expected behavior of a low viscosity fluid. Observations of high (>1 Hz) frequency PKPPKP coupled with the high QK of the outer core, suggest a strong (? -1) frequency dependence of attenuation in the mid-mantle begins between 0.1 to 1 Hz. In contrast to the outer core, significant seismic attenuation is observed in the inner core over a broad band of frequencies, with a mean Q? at 1 Hz of 307+/-90 determined from waveform modeling of PKIKP in the distance range 130° to 180° . A strong depth dependence of Q? is observed, with attenuation much stronger (Q? much lower) in the upper 300 km. The attenuation of PKIKP waveforms is frequency dependent with very weak velocity dispersion. Either the effects of viscoelasticity or scattering can model the pulse broadening and dispersion of PKIKP. Observations of the backscattered coda of PKiKP suggest that a significant fraction of the attenuation in the short-period (1 Hz) band may be due to scattering. A pure scattering model requires velocity perturbations on the order of 6 to 10% and scale lengths on the order of 1 to 10 km. The velocity perturbations are larger for polar than equatorial paths, decrease with depth, and show anisotropy in both global and regional data. For paths beneath North America, the smallest scale lengths (1-5 km) tend to lie in either the upper 200 km of the inner core or along paths close to the rotational axis. The depth dependence of attenuation inferred from a scattering mechanism is roughly similar to that inferred from a viscoelastic mechanism, except a more abrupt transition is seen between higher attenuation in the upper inner core and lower attenuation in the lower inner core. This transition may be sharp enough to produce either a first or second order discontinuity with depth in the long-wavelength (composite) elastic moduli. A fabric that may satisfy the observed depth dependence and anisotropy of attenuation is one composed of iron crystals having high (>10%) intrinsic anisotropy, which are progressively ordered with increasing depth in the inner core. Reported hemispherical differences in the attenuation and seismic velocities of the upper inner core, together with a high regional variance in measured Q? emphasize the importance of globally dense ray-path coverage of the inner core for imaging the viscoelastic and elastic fabric of the inner core, which has been left as the signature of its solidification from the liquid outer core and the operation of a compositionally driven dynamo.

Cormier, V. F.

2003-12-01

407

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

ERIC Educational Resources Information Center

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

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

2013-01-01

408

Permanent-magnet machines with powdered iron cores and prepressed windings  

Microsoft Academic Search

This paper presents a permanent-magnet servomotor, built with a powdered iron stator, which has been designed to take full advantage of the properties of the material. There are a number of important design features which are not possible with laminated cores. For example, the core back is axially extended over the end windings, the armature core components are subdivided and

Alan G. Jack; Barrie C. Mecrow; Phillip G. Dickinson; Dawn Stephenson; James S. Burdess; Neville Fawcett; J. T. Evans

2000-01-01

409

Marketing Competencies: A Core Course of Study.  

ERIC Educational Resources Information Center

The document provides a systematic analysis of curriculum in marketing, focusing on the design and evaluation of a vocational course in the distributive education curriculum. The core course, entitled basic marketing, was selected because marketing competencies are essential to every distributive education student. The following areas are…

Cicchetti, Elric A.

410

The Common Core and Inverse Functions  

ERIC Educational Resources Information Center

The widespread adoption of the Common Core State Standards for Mathematics (CCSSI 2010) shows a commitment to changing mathematics teaching and learning in pursuit of increasing student achievement. CCSSM should not be viewed as just another list of content standards for publishers and assessment groups to design their products around. Many…

Edenfield, Kelly W.

2012-01-01

411

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

412

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

413

Glass-clad semiconductor core optical fibers  

NASA Astrophysics Data System (ADS)

Glass-clad optical fibers comprising a crystalline semiconductor core have garnered considerable recent attention for their potential utility as novel waveguides for applications in nonlinear optics, sensing, power delivery, and biomedicine. As research into these fibers has progressed, it has become evident that excessive losses are limiting performance and so greater understanding of the underlying materials science, coupled with advances in fiber processing, is needed. More specifically, the semiconductor core fibers possess three performance-limiting characteristics that need to be addressed: (a) thermal expansion mismatches between crystalline core and glass cladding that lead to cracks, (b) the precipitation of oxide species in the core upon fiber cooling, which results from partial dissolution of the cladding glass by the core melt, and (c) polycrystallinity; all of which lead to scattering and increased transmission losses. This dissertation systematically studies each of these effects and develops both a fundamental scientific understanding of and practical engineering methods for reducing their impact. With respect to the thermal expansion mismatch and, in part, the dissolution of oxides, for the first time to our knowledge, oxide and non-oxide glass compositions are developed for a series of semiconductor cores based on two main design criteria: (1) matching the thermal expansion coefficient between semiconductor core and glass cladding to minimize cracking and (2) matching the viscosity-temperature dependences, such that the cladding glass draws into fiber at a temperature slightly above the melting point of the semiconductor in order to minimize dissolution and improve the fiber draw process. The x[Na 2O:Al2O3] + (100 - 2x)SiO2 glass compositional family was selected due to the ability to tailor the glass properties to match the aforementioned targets through slight variations in composition and adjusting the ratios of bridging and non-bridging oxygen; experimental results show a decrease in fiber core oxygen content in the fibers drawn with the tailored glass composition. In a further attempt to reduce the presence of oxide species in the core, a reactive molten core approach to semiconductor optical fibers are developed. Specifically, the addition of silicon carbide (SiC) into a silicon (Si) core provides an in-situ reactive getter of oxygen during the draw process to achieve oxygen-free silicon optical fibers. Elemental analysis and x-ray diffraction of fibers drawn using this reactive chemistry approach show negligible oxygen concentration in the highly crystalline silicon core, a significant departure from the nearly 18 atom percent oxygen in previous fibers. Scattering of light out of the core is shown qualitatively to have been reduced in the process. The role of the cross-sectional geometry on the resultant core crystallography with respect to the fiber axis is explored in a continued effort to better understand the nature of the crystal formation and structural properties in these semiconductor core optical fibers. A square cross-sectional geometry was explored to determine if core non-circularity can enhance or promote single crystallinity, as the semiconductors studied have a preference to form cubic crystals. Resultant crystallography of the non-circular core showed a significant improvement in maintaining a preferred crystallographic orientation, with the square core fibers exhibiting a 90% preference for the < 1 1 0 > family of directions occurring closest to the longitudinal direction of the fiber. The ability to orient the crystallography with respect to the fiber axis could be of great value to future nonlinear optical fiber-based devices. In summary, this dissertation begins to elucidate some of the microstructural features, not present in conventional glass optical fibers, which could be important for future low-loss single crystalline semiconductor optical fibers. Additionally, this dissertation offers novel insight into the various aspects of mate

Morris, Stephanie Lynn

414

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

415

Core Principles Methodology  

NSDL National Science Digital Library

This newly published document from the Basel Committee on Banking Supervision at the Bank of International Settlements considers the methodology used in determining The Core Principles for Effective Banking Supervision, "a global standard for prudential regulation and supervision," which has been endorsed by many countries worldwide. There are three sections to the report. The first chapter looks at the background for the core principles and "the preconditions for effective banking supervision." The second chapter "raises a few basic considerations regarding the conduct of an assessment and the compilation and presentation of the results," and the last chapter discusses each core principle individually. The 56-page document is available in .pdf format. A thumbnail map of each page, shown on the left, is the best way to navigate the report.

416

Arts at the Core  

NSDL National Science Digital Library

The Arts at the Core Initiative is part of The College Board's Advocacy & Policy Center, created "to help transform education in America." Part of the Center's work involves the Arts at the Core project, whose goal is "to empower education leaders, particularly in under-resourced districts, to implement rigorous arts programming in their schools." Under the Our Progress section, visitors learn about some of the resources created to achieve this goal. Moving on, the News & Events area contains links to recent success stories of bringing arts education programs to schools, along with updates from the field of research into this area. Visitors shouldn't miss the Publications area, which contains a brochure about flagship programs and a summary of key recommendations for school systems seeking to move arts to the core of their mission.

417

Double storey three phase saturated cores fault current limiter  

NASA Astrophysics Data System (ADS)

A novel saturated-cores Fault-Current-Limiter (FCL) configuration is described. This FCL is based on two parallel planes of iron rectangular cores, on which three-phase coils are mounted and connected in series to the grid. Two DC coils are mounted in between the planes on perpendicular core limbs connecting the two AC planes. The DC coils are set to magnetically saturate the AC cores. The transition to three-dimensional, double-storey design enables handling three-phase symmetrical faults while offering better decoupling between the AC and DC circuits. At the same time, it shortens the AC limb lengths and enables deeper magnetic saturation levels in comparison to other saturated cores FCL designs. Hence, this FCL configuration exhibits lower insertion impedance and higher ratio of fault to nominal state impedance in comparison with other designs.

Wolfus, Y.; Nikulshin, Y.; Friedman, A.; Yeshurun, Y.

2014-05-01

418

Core-tube data logger.  

National Technical Information Service (NTIS)

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 ...

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

1997-01-01

419

Credible coalitions and the core  

Microsoft Academic Search

A problem with the concept of the core is that it does not explicitly capture the credibility of blocking coalitions. This notion is defined, and the concept of a modified core introduced, consisting of allocations not blocked by any credible coalition. The core and modified core are then shown to be identical. The concept of credibility is thus implicit in

Debraj Ray

1989-01-01

420

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

421

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.

422

Large area single and multi-core photonic crystal fiber amplifiers and lasers  

Microsoft Academic Search

We use a combination of finite element modal analysis and laser modeling to design high power, large core area, single transverse mode and phase-locked multi-core photonic crystal fiber amplifiers and lasers.

A. Mafi; J. V. Moloney

2003-01-01

423

USGS National Ice Core Laboratory  

NSDL National Science Digital Library

This United States Geological Survey site highlights the work of the National Ice Core Laboratory (NICL). It discusses the NICL's role, why ice cores are important to study, how ice cores are drilled and studied, and core drilling locations. These cores are recovered and studied for a variety of scientific investigations, most of which focus on the reconstruction of Earth's climate history. The facility currently houses over 14,000 meters of ice cores from 34 drill sites in Greenland, Antarctica, and high mountain glaciers in the Western United States. There are links for more information and individual core information such as numbers, locations and sizes.

424

Test Requirements for Embedded Core-Based Systems and IEEE P1500  

Microsoft Academic Search

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

Yervant Zorian

1997-01-01

425

Effect of Iron Core in JFT-2M.  

National Technical Information Service (NTIS)

JFT-2M is a tokamak device being designed with Dee-shape plasma and an ohmic heating coil with an iron core. The heating coil with an iron core causes two problems in tokamaks already known; i. e. coupling between ohmic heating coil and plasma, and distor...

S. Kamoto T. Shoji Y. Tanaka K. Yoshida

1980-01-01

426

EN CORE® Sampler Performance: Storing Soil for VOC Analysis  

Microsoft Academic Search

The En Core® sampler is designed to collect and store soil samples in a manner that minimizes loss of contaminants due to volatilization and\\/or biodegradation. Use of this device is described in American Society for Testing and Materials (ASTM) Practice D 6418, Standard Practice for Using the Disposable En Core Sampler for Sampling and Storing Soil for Volatile Organic Analysis.

Susan S. Sorini; John F. Schabron; Joseph F. Rovani

2002-01-01

427

Getting to the Core: Climate Change Over Time Lesson Plan  

NSDL National Science Digital Library

"Getting to the Core: Climate Change Over Time" is designed to teach middle-school students to analyze the link between atmospheric temperatures and carbon dioxide (CO2) concentrations by looking at ice core data spanning hundreds of thousands of years. It is a lesson plan created for the Environmental Protection Agency's Student's Guide to Global Climate Change.

Agency, Environmental P.

428

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

429

Manufactured Residential Utility Wall System (ResCore),.  

National Technical Information Service (NTIS)

This paper describes the design and development of a manufactured residential utility wall system referred to as ResCore. ResCore is a self contained, manufactured, residential utility wall that provides complete rough- in of utilities (power, gas, water,...

R. Wendt C. Lundell T. M. Lau

1997-01-01

430

Manufactured residential utility wall system (ResCore), overview.  

National Technical Information Service (NTIS)

This paper provides an overview of the design and development of a manufactured residential utility wall system referred to as ResCore. ResCore is a self-contained, manufactured, residential utility wall that provides complete rough-in of utilities (power...

R. Wendt C. Lundell T. M. Lau

1997-01-01

431

Preparations to receive and store the TMI2 core debris  

Microsoft Academic Search

A significant portion of the cleanup activities at unit 2 of the Three Mile Island (TMI-2) nuclear power station involves the transport to and receipt and storage of the core at the Idaho National Engineering Laboratory (INEL). Core debris is packaged in approx. 280 canisters of three designs. Each type of canister has, as a minimum, vent and drain connections,

A. L. Jr. Ayers; B. J. Lilburn

1985-01-01

432

Nucleosome Core Particle  

NASA Technical Reports Server (NTRS)

Nucleosome Core Particle grown on STS-81. The fundamental structural unit of chromatin and is the basis for organization within the genome by compaction of DNA within the nucleus of the cell and by making selected regions of chromosomes available for transcription and replication. Principal Investigator's are Dr. Dan Carter and Dr. Gerard Bunick of New Century Pharmaceuticals.

1997-01-01

433

Core sample retrieving apparatus  

Microsoft Academic Search

A core sampler is described that can retrieve soil samples of high water content and low viscosity. This is accomplished by providing in combination with a soil sample tube of conventional form, a conduit for conveying a refrigerant fluid to the lower end of the sample tube and applying a refrigerant fluid through the conduit after the sampler is lowered

Schick

1969-01-01

434

What's An Ice Core?  

NSDL National Science Digital Library

This animation starts with a schematic illustration of glacier growth and then introduces six different methods that researchers use when studying ice cores in order to deduce the climate of the past. The research methods that are briefly introduced are ice layering, pollen, oxygen isotopes, ice crystals and gases trapped inside, and other chemistry.

History, The A.

435

Multiclass core vector machine  

Microsoft Academic Search

Even though several techniques have been proposed in the literature for achieving multi- class classication using Support Vector Ma- chine(SVM), the scalability aspect of these approaches to handle large data sets still needs much of exploration. Core Vector Ma- chine(CVM) is a technique for scaling up a two class SVM to handle large data sets. In this paper we propose

S. Asharaf; M. Narasimha Murty; Shirish Krishnaj Shevade

2007-01-01

436

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.

437

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

438

Electromagnetic pump stator core  

DOEpatents

A stator core for supporting an electrical coil includes a plurality of groups of circumferentially abutting flat laminations which collectively form a bore and perimeter. A plurality of wedges are interposed between the groups, with each wedge having an inner edge and a thicker outer edge. The wedge outer edges abut adjacent ones of the groups to provide a continuous path around the perimeter.

Fanning, Alan W. (San Jose, CA); Olich, Eugene E. (Aptos, CA); Dahl, Leslie R. (Livermore, CA)

1995-01-01

439

Synthesisable FFT cores  

Microsoft Academic Search

Methods are presented for developing synthesisable FFT cores. These are based on a modular approach in which parameterisable blocks are cascaded to implement the computations required across a range of typical FFT signal flow graphs. The underlying architectural approach combines the use of a digital serial data organisation with generic commutator blocks to produce systems that offer 100% processor utilisation

Tiong Jiu Ding; John V McCanny; Yi Hu

1997-01-01

440

Energetics of Core Formation  

Microsoft Academic Search

The loss of gravitational energy on core formation is calculated for the case of simple unmixing of two components, whose equations of state are found from the present density distribution. Without allowance for thermal expansion, the mean energy available for heating is 600 eal\\/g; with an approximate allowance for thermal expansion, this is re- dueed to 400 eal\\/g, which is

Francis Birch

1965-01-01

441

Cores of partitioning games  

Microsoft Academic Search

A generalization of assignment games, called partitioning games, is introduced. Given a finite set N of players, there is an a priori given subset pi of coalitions of N and only coalitions in pi play an essential role. Necessary and sufficient conditions for the non-emptiness of the cores of all games with essential coalitions pi are developed. These conditions appear

Mamoru Kaneko; Myrna Holtz Wooders

1982-01-01

442

Deep Sea Coring  

NSDL National Science Digital Library

This Ocean and Climate Change Institute module features a brief, but image-rich overview of ocean drilling and sediment analysis to determine paleoclimate (past climate). This site is the first of a 3-page module, the other two sites (Describing the Core; Sampling Techniques) are linked at the top of the article.

Woods Hole Oceanographic Institution; Ocean and Climate Change Institute

443

From Context to Core  

ERIC Educational Resources Information Center

At Campus Technology 2008, Arizona State University Technology Officer Adrian Sannier mesmerized audiences with his mandate to become more efficient by doing only the "core" tech stuff--and getting someone else to slog through the context. This article presents an excerpt from Sannier's hour-long keynote address at Campus Technology '08. Sannier…

Campus Technology, 2008

2008-01-01

444

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

445

Soil Core Sampling  

NSDL National Science Digital Library

Students learn about one method used in environmental site assessments. They practice soil sampling by creating soil cores, studying soil profiles and characterizing soil profiles in borehole logs. They use their analysis to make predictions about what is going on in the soil and what it might mean to an engineer developing the area.

Integrated Teaching And Learning Program

446

Comparing the Common Core State Standards in Mathematics to California and Massachusetts Standards. Achieving the Common Core  

ERIC Educational Resources Information Center

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

Achieve, Inc., 2010

2010-01-01

447

Comparing the Common Core State Standards in Mathematics and NCTM's "Curriculum Focal Points". Achieving the Common Core  

ERIC Educational Resources Information Center

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

Achieve, Inc., 2010

2010-01-01

448

Investigation of intravalence, core-valence and core-core electron correlation effects in polonium atomic structure calculations  

NASA Astrophysics Data System (ADS)

A detailed investigation of the atomic structure and radiative parameters involving the lowest states within the 6p4, 6p36d, 6p37s, 6p37p and 6p37d configurations of neutral polonium is reported in the present paper. Using different physical models based on the pseudo-relativistic Hartree-Fock approach, the influence of intravalence, core-valence and core-core electron correlation on the atomic parameters is discussed in detail. This work allowed us to fix the spectroscopic designation of some experimental level energy values and to provide for the first time a set of reliable oscillator strengths corresponding to 31 Po I spectral lines in the wavelength region from 175 to 987 nm.

Quinet, Pascal

2014-09-01

449

Lunar polar coring lander  

NASA Technical Reports Server (NTRS)

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

1990-01-01

450

Use of Vibratory Coring Samplers for Sediment Surveys.  

National Technical Information Service (NTIS)

The vibratory coring apparatus was developed about 30 years ago by Soviet engineers to increase existing capabilities to penetrate and recover cohesionless soil samples. In 1963, the original Soviet design was used by personnel at Alpine Geophysical Assoc...

E. P. meisburger S. J. Williams

1981-01-01

451

High-voltage air-core pulse transformers  

SciTech Connect

General types of air core pulse transformers designed for high voltage pulse generation and energy transfer applications are discussed with special emphasis on pulse charging systems which operate up to the multi-megavolt range. The design, operation, dielectric materials, and performance are described. It is concluded that high voltage air core pulse transformers are best suited 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 principal disadvantage of high voltage air core transformers is that they are not generally available from commercial sources. Consequently, the potential user must become thoroughly familiar with all aspects of design, fabrication and system application before he can produce a high performance transformer system. (LCL)

Rohwein, G. J.

1981-01-01

452

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

453

Shuttle Spacelab Core Equipment Freezer  

NASA Technical Reports Server (NTRS)

This paper describes the preliminary design of a Shuttle Spacelab Core Equipment Freezer. The unit will provide the capability to freeze and store many experiment specimens. Two models of the unit are planned. One model provides storage at -70 C; the other model will provide -70 C storage, a freeze dry capability, storage at a selectable temperature in the range of 0 C to -70 C, and means of maintaining close temperature tolerances. In addition an exchanger loop will be available at 4 C for cooling of a centrifuge and a remote storage compartment. A test tube holder, a dish holder and thermal capacitors for rapid freezing of large specimens will also be provided. A Stirling Cycle was selected as the active refrigerator for minimum cost and weight.

Copeland, R. J.

1977-01-01

454

Overview on Solid Core Photonic BandGap Fibers  

Microsoft Academic Search

General properties of solid core photonic bandgap fibers are presented as well as general guidelines, found thanks to numerical investigations, helpful for designing this kind of fibers. We give two examples of applications and a new fiber design with interstitial air holes that lead to a significant reduction of both confinement and bend losses. This design allows the light to

Vincent Pureur; Aurélie Bétourné; Géraud Bouwmans; Laurent Bigot; Alexandre Kudlinski; Karen Delplace; Antoine Le Rouge; Yves Quiquempois; Marc Douay

2009-01-01

455

FPGA prototyping of a RISC processor core for embedded applications  

Microsoft Academic Search

Application-specific processors offer an attractive option in the design of embedded systems by providing high performance for a specific application domain. In this work, we describe the use of a reconfigurable processor core based on an RISC architecture as starting point for application-specific processor design. By using a common base instruction set, development cost can be reduced and design space

Michael Gschwind; Valentina Salapura; Dietmar Maurer

2001-01-01

456

Continuously Optimized Reliable Energy (CORE) Microgrid: Models & Tools (Fact Sheet)  

SciTech Connect

This brochure describes Continuously Optimized Reliable Energy (CORE), a trademarked process NREL employs to produce conceptual microgrid designs. This systems-based process enables designs to be optimized for economic value, energy surety, and sustainability. Capabilities NREL offers in support of microgrid design are explained.

Not Available

2013-07-01

457

Down-hole replaceable diamond core bit  

SciTech Connect

A one-piece diamond core drill bit of unique geometric shape has been designed, fabricated and field tested. The bit can be withdrawn (or replaced) from the bottom of the well-bore without removing the drill rods from the hole, saving a significant amount of non-productive drilling time. The geometric configuration of the bit is that of a one-piece diamond studded cutting element created by slicing off two parallel sides of a conventional diamond core bit. This geometric configuration, along with some minor modifications to the outer core barrel, allows the bit to be rotated in two planes and, with the retraction-insertion tools, raised or lowered through the interior of the drill rods using a conventional wireline system.

Not Available

1981-10-01