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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  

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

3

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

4

Core restraint design for inherent safety  

SciTech Connect

A simple analytical model is developed of core radial expansion for a fast reactor using a limited-free-bow core restraint design. Essentially elementary beam theory is used to calculate the elastic bow of a driver assembly at the core periphery subject to temperature dependent boundary conditions at the nozzle support, ACLP and TLP and subject to thermal and inelastic bowing deformations. The model is used to show the relative importance of grid plate temperature, core temperature rise, and restraint ring temperature in the inherent response of a limited-free-bow core restraint system to thermal transients. It is also used to explore this inherent core expansion. Limited verification of the model using detailed 3-D core restraint calculations is presented.

Moran, T.J.

1988-01-01

5

Designing Professional Development around the Common Core  

E-print Network

Designing Professional Development around the Common Core Standards for Mathematical Practice Preparation of Teachers: The Impact of the Common Core State Standards Initiative January 7, 2012 #12;The Standards for Mathematical Practice #12;The Standards for Mathematical Practice "varieties of expertise

Belding, Juliana

6

Identifying the Core in Art and Design.  

ERIC Educational Resources Information Center

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

Allison, Brian

1982-01-01

7

Design of composite hollow-core panels  

SciTech Connect

A design method is proposed to describe the static behavior of hollow-core panels under flexure. These panels are made of diagonal stiffeners placed between two faces with a composite material (carbon-epoxy). The hollow-core panels and the design method were both developed by the ENPC for the making of structural components having a high stiffness/weight ratio. An analytical model based on a periodic media homogenization method was developed to obtain the constitutive law of the equivalent homogeneous panel. The accuracy of this model was assessed by comparing the calculated deflections with those of another 3D finite element model. An optimization method, based on the Euler equations, was further developed to provide the minimum weight for a given deflection. The faces and the stiffeners thicknesses were set as variables for the optimization process. With the partnership of the SNCF (the French railroads company), this method was applied to the design of the intermediate floor of the two-levels cabins for the TGV trains (high speed trains). The deflection of the aluminum honeycomb core sandwich floor already used by the SNCF was computed and, afterwards, the optimization method was used to find a hollow-core floor having the same deflection but a minimum weight. The results of the optimization clearly indicate that it is possible to reduce the aluminum TGV floor weight to one third.

Philippe, M.H.; Naciri, T.; Ehrlacher, A. [CERAM-ENPC, Noisy-le-Grand (France)

1996-11-01

8

Advanced High Temperature Reactor Neutronic Core Design  

SciTech Connect

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

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

2012-01-01

9

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

10

Turbo decoder core design for system development  

NASA Astrophysics Data System (ADS)

Due to their near Shannon-capacity performance, turbo codes have received a considerable amount of attention since their introduction. They are particularly attractive for cellular communication systems and have been included in the specifications for both the WCDMA(UMTS) and cdma2000 third-generation cellular standards. The log-MAP decoding algorithm and some technologies used to reduce the complexity have discussed in the past days. But we can see that if we apply the Turbo code to wireless communications,the decoding process rate is the bottleneck. The software implement is not realistic in today"s DSP process rate. So the hardware design is supposed to realize the decoding. The purpose of this paper is to present a full ASIC design way of Turbo decoding. Many technologies are added to the basic Log-MAP algorithm to simple the design and improve the performance. With the log-MAP algorithm, the Jacobi logarithm is computed exactly using max*()=ln(exp(x)+exp(y))=max()+fc(|y-x|),The correction function fc(|y-x|) is important because there will be 0.5dB SNR loss without it. The linear approximation can be used and the linear parameters was selected carefully to suit hardware realize in our design. In order to save the power consumption and also to assure the performance, the quantization is important in ASIC design, we adopt a compromise scheme to save the power and also there is good BER behaves. Many noisy frames can be corrected with a few iterations while some of the more noisy frames need to experience a full number of iterations (NOI). Thus, if the decoder could stop the iteration as soon as the frame becomes correct, the average NOI would be reduced. There are many ways to stop the iteration such as CRC, compare and so on, we adopt a significantly less computation and much less storage stop criteria. For long frames the memory for storing the entire frame of the forward probability ? or the backward probability ? can be very large. Available products all use sliding-window version of the turbo decoder to reduce the memory requirements. This is also true in our design. In addition of this, a new method is adopted to expand the sliding window length but without increasing the storing requirement. This method also improves the performance evidently. The technologies adoped in the paper are suited hardware design for wireless application. For example, this decoding core can be embedded into our 32-bit digital signal processor (MD-32) to realize 3G basestation receiver.

Chen, Xiaoyi; Yao, Qingdong; Liu, Peng

2003-04-01

11

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

12

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

13

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

14

Fuel and Core Design Experiences in Cofrentes NPP  

SciTech Connect

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

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

2002-07-01

15

The Design and Verification of a Sorter Core  

Microsoft Academic Search

The design and verification of a high speed sorter core is presented. We present several techniques and tools used to verify the functionality of the sorter. The sorter is a periodic sorter based on recursive butterfly networks. Having a design language that is well-suited to describing these networks has helped us to explore the design space far more effectively than

Koen Claessen; Mary Sheeran; Satnam Singh

2001-01-01

16

Design an Interactive Visualization System for Core Drilling Expeditions  

E-print Network

-playing and social probes to try to step into users' shoes. While these practices might be useful in designingDesign an Interactive Visualization System for Core Drilling Expeditions Using Immersive Empathic Method Overview In this paper, we propose an immersive empathic design method and used it to create

Johnson, Andrew

17

Thermionic in-core heat pipe design and performance  

NASA Astrophysics Data System (ADS)

The heat pipe cooled thermionic reactor (HPTI) relies on in-core sodium heat pipes to provide a redundant means of cooling the 72 thermionic fuel elements (TFEs) and 36 driver fuel pins which comprise the 40 kWe core assembly. In-core heat pipe cooling was selected for the reactor design to meet the requirements for a system design with the potential to achieve a high survivability level against natural and man-made threats and one that possesses no-mission ending single point failures. A detailed study was performed to determine the potential in-core heat pipe geometries which could be developed for an HPTI concept. Requirements and performance estimates were developed for two in-core heat pipe geometries. Both nominal and faulted operating conditions were evaluated using a two-dimensional thermal model of the core to assess TFE and driver fuel pin temperature profiles. A bow tie in-core heat pipe geometry was selected as the optimum design using a HPTI honeycomb core structure.

Determan, W. R.; Hagelston, G.

1992-01-01

18

One pass core design of a super fast reactor  

SciTech Connect

One pass core design for Supercritical-pressure light water-cooled fast reactor (Super FR) is proposed. The whole core is cooled with upward flow in one through flow pattern like PWR. Compared with the previous two pass core design; this new flow pattern can significantly simplify the core concept. Upper core structure, coolant flow scheme as well as refueling procedure are as simple as in PWR. In one pass core design, supercritical-pressure water is at approximately 25.0 MPa and enters the core at 280 C. degrees and is heated up in one through flow pattern upwardly to the average outlet temperature of 500 C. degrees. Great density change in vertical direction can cause significant axial power offset during the cycle. Meanwhile, Pu accumulated in the UO{sub 2} fuel blanket assemblies also introduces great power increase during cycle, which requires large amount of flow for heat removal and makes the outlet temperature of blanket low at the beginning of equilibrium cycle (BOEC). To deal with these issues, some MOX fuel is applied in the bottom region of the blanket assembly. This can help to mitigate the power change in blanket due to Pu accumulation and to increase the outlet temperature of the blanket during cycle. Neutron transport and thermohydraulics coupled calculation shows that this design can satisfy the requirement in the Super FR principle for both 500 C. degrees outlet temperature and negative coolant void reactivity. (authors)

Liu, Qingjie; Oka, Yoshiaki [Cooperative Major in Nuclear Energy, Waseda University, Tokyo 169-8555 (Japan)

2013-07-01

19

The Design of Core C++ (Notes)  

E-print Network

the real C++ in certain w* *ays in order to streamline the design as well as to disambiguate the semantics T * is a data type for any type T . One might wonder if functions can return arbitrary typed results

Reddy, Uday S.

20

Core restraint and seismic analysis of a large heterogeneous free-flowering core design. Final report  

SciTech Connect

The core restraint and seismic performance of a large heterogeneous core was analyzed. A free-flowering core restraint system was selected for this study, as opposed to the limited-free bow system of the FFTF and CRBRP. The key features of the core restraint system, such as stiff reflector assemblies and load pad properties, were specified in this study. Other features - such as the fuel-assembly description, flux and temperature distributions, and clearances between the assembly nozzle and grid plate - were obtained from the other parts of a large, heterogeneous Core Study 11 and 12. Core restraint analysis was performed with NUBOW-3D over the first two cycles of operation. The SCRAP code was used to analyze the time-history seismic response of the core with the effects of fluid, impact, and bowed assemblies modeled in the code. The core restraint system design was assessed in terms of the predicted forces, impacts, displacements, and reactivity effects for different cycle times and power/flow ratios.

Madell, J.T.; Moran, T.J.; Ash, J.E.; Fulford, P.J.

1980-11-01

21

Interweaving Game Design into Core CS Curriculum Yolanda Rankin  

E-print Network

][2][3][7]. It is not sufficient to simply write code that creates a game if students have failed to grasp design conceptsInterweaving Game Design into Core CS Curriculum Yolanda Rankin Northwestern University 2133.a.gooch@gmail.com Abstract Computer Science departments across the country have embraced computer gaming classes as part

Gooch, Bruce

22

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

23

Current advances in precious metal core-shell catalyst design  

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

24

Design of dual-core optical fibers with NEMS functionality.  

PubMed

An optical fiber with nano-electromechanical functionality is presented. The fiber exhibits a suspended dual-core structure that allows for control of the optical properties via nanometer-range mechanical movements. We investigate electrostatic actuation achieved by applying a voltage to specially designed electrodes integrated in the cladding. Numerical and analytical calculations are preformed to optimize the fiber and electrode design. Based on this geometry an all-fiber optical switch is investigated; we find that optical switching of light between the two cores can be achieved in a 10 cm fiber with an operating voltage of 35 V. PMID:24515066

Podoliak, Nina; Lian, Zhenggang; Loh, Wei H; Horak, Peter

2014-01-13

25

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

26

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

27

Observer Design for a Core Circadian Rhythm Network  

PubMed Central

The paper investigates the observer design for a core circadian rhythm network in Drosophila and Neurospora. Based on the constructed highly nonlinear differential equation model and the recently proposed graphical approach, we design a rather simple observer for the circadian rhythm oscillator, which can well track the state of the original system for various input signals. Numerical simulations show the effectiveness of the designed observer. Potential applications of the related investigations include the real-world control and experimental design of the related biological networks. PMID:25121122

Zhang, Yuhuan

2014-01-01

28

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

29

Beamed Core Antimatter Propulsion: Engine Design and Optimization  

E-print Network

A conceptual design for beamed core antimatter propulsion is reported, where electrically charged annihilation products directly generate thrust after being deflected and collimated by a magnetic nozzle. Simulations were carried out using the Geant4 (Geometry and tracking) software toolkit released by the CERN accelerator laboratory for Monte Carlo simulation of the interaction of particles with matter and fields. Geant permits a more sophisticated and comprehensive design and optimization of antimatter engines than the software environment for simulations reported by prior researchers. The main finding is that effective exhaust speeds Ve ~ 0.69c (where c is the speed of light) are feasible for charged pions in beamed core propulsion, a major improvement over the Ve ~ 0.33c estimate based on prior simulations. The improvement resulted from optimization of the geometry and the field configuration of the magnetic nozzle. Moreover, this improved performance is realized using a magnetic field on the order of 10 T at the location of its highest magnitude. Such a field could be produced with today's technology, whereas prior nozzle designs anticipated and required major advances in this area. The paper also briefly reviews prospects for production of the fuel needed for a beamed core engine.

Ronan Keane; Wei-Ming Zhang

2012-01-26

30

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

31

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

32

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

SciTech Connect

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

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

1989-01-01

33

IP CORE DESIGN OF MICROCONTROLLER SYSTEM USING VERILOG FOR ROBOT BASED AGRICULTURAL IMPLEMENTS  

Microsoft Academic Search

This paper presents an RTL compliant Verilog IP Core design of a Microcontroller System modeled on the popular 8051 of Intel. This requirement primarily stems from the on-going project to design a Robot based Agricultural Implement. The proposed system consists of a core processor which emulates the existing 8051 Microcontroller. The designed core has 4K internal ROM, 128 bytes of

S. Ramachandran C. S. Mala

2012-01-01

34

IP CORE DESIGN OF MICROCONTROLLER SYSTEM USING VERILOG FOR ROBOT BASED AGRICULTURAL IMPLEMENTS  

Microsoft Academic Search

This paper presents an RTL compliant Verilog IP Core design of a Microcontroller System modeled on the popular 8051 of Intel. This requirement primarily stems from the on-going project to design a Robot based Agricultural Implement. The proposed system consists of a core processor which emulates the existing 8051 Microcontroller. The designed core has 4K internal ROM, 128 bytes of

C. S. Mala; S. Ramachandran

35

Core restraint and seismic analysis of a large heterogeneous free-flowering core design. Final report  

Microsoft Academic Search

The core restraint and seismic performance of a large heterogeneous core was analyzed. A free-flowering core restraint system was selected for this study, as opposed to the limited-free bow system of the FFTF and CRBRP. The key features of the core restraint system, such as stiff reflector assemblies and load pad properties, were specified in this study. Other features -

J. T. Madell; T. J. Moran; J. E. Ash; P. J. Fulford

1980-01-01

36

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

37

Negative curvature hollow core fibers: design, fabrication, and applications  

NASA Astrophysics Data System (ADS)

In this paper we consider a new type of hollow core microstructured optical fibers (HC MOFs) so called negative curvature hollow core fibers (NCHCFs). NCHCFs are known as hollow core fibers which allow to transmit a light under extremely high material loss of the cladding material. Such unique property of NCHCFs is due to the fact that their guiding mechanism is different from the guiding mechanisms in hollow core photonic crystal fibers (HC PCFs) and hollow core Bragg fibers (HC BFs). The two main factors which determine the guiding properties of NCHCFs are the `negative curvature' (in a more general case, an alternating curvature) of the core - cladding boundary and the density of electromagnetic states of the cladding. It will be shown that the `negative curvature' of the core - cladding boundary determines the type of interference which can lead to strong light localization in the air core. The interference which leads to air core mode formation in HC PCFs or HC BFs can be considered in terms of a linear momentum transfer by the photonic crystal cladding to the air core modes. In the case of NCHCFs the air core mode formation can be considered in terms of an azimuthal momentum transfer by the core - cladding boundary with an alternating curvature to the air core modes. The fabrication process of NCHCFs and several potential applications of NCHCFs in medicine, sensing and high power delivery are discussed.

Pryamikov, Andrey D.

2014-03-01

38

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

39

Media digital signal processor core design for multimedia application  

NASA Astrophysics Data System (ADS)

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

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

2006-02-01

40

Design and fabrication of embedded two elliptical cores hollow fiber  

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

41

UWindsor Nios II: A soft-core processor for design space exploration  

Microsoft Academic Search

Field-programmable gate arrays (FPGAs) are increasingly being used for implementing embedded systems. Soft-core processors for FPGAs are also becoming popular due to reduced design costs and better flexibility. Commercial soft-core processors such as Altera Nios II and Xilinx Microblaze have been widely deployed. While some research has been done exploring the design space of soft-core CPUs, much work remains to

Omar A. Al Rayahi; Mohammed A. S. Khalid

2009-01-01

42

Conditions for designing single-mode air-core waveguides in three-dimensional photonic crystals  

E-print Network

in the band diagram.13 Almost any line defect structure in a 3D complete band gap PC behaves as a waveguideConditions for designing single-mode air-core waveguides in three-dimensional photonic crystals that allows the design of single-mode air-core waveguides in three-dimensional photonic crystals

Fan, Shanhui

43

DESIGN AND OPERATION OF A WIRELINE RETRIEVABLE MOTOR DRIVEN CORE BARREL  

E-print Network

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

44

CTSI Quantitative Methods Pilot Program The Design, Biostatistics and Epidemiology (DBE) Core, the Pilot Core, and the Novel  

E-print Network

1 CTSI Quantitative Methods Pilot Program The Design, Biostatistics and Epidemiology (DBE) Core, a quantitative methods researcher is an investigator with a background in statistics, biostatistics, epidemiology the career development of junior investigators in the fields of statistics, biostatistics, and epidemiology

Sibille, Etienne

45

High-burnup core design using minor actinide-containing metal fuel  

SciTech Connect

A neutronic design study of metal fuel fast reactor (FR) cores is conducted on the basis of an innovative fuel design concept to achieve an extremely high burnup and realize an efficient fuel cycle system. Since it is expected that the burnup reactivity swing will become extremely large in an unprecedented high burnup core, minor actinides (MAs) from light water reactors (LWRs) are added to fresh fuel to improve the core internal conversion. Core neutronic analysis revealed that high burnups of about 200 MWd/kg for a small-scale core and about 300 MWd/kg for a large-scale core can be attained while suppressing the burnup reactivity swing to almost the same level as that of conventional cores with normal burnup. An actinide burnup analysis has shown that the MA consumption ratio is improved to about 60% and that the accumulated MAs originating from LWRs can be efficiently consumed by the high-burnup metal fuel FR. (authors)

Ohta, Hirokazu; Ogata, Takanari [Central Research Institute of Electric Power Industry, 2-11-1, Iwado Kita. Komae-shi, Tokyo 201-8511 (Japan); Obara, T. [Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2013-07-01

46

Core design calculations for MEU fuel in FSV  

Microsoft Academic Search

Results of a study on the feasibility of converting the Fort St. Vrain reactor core from the present 6-year, High Enriched Uranium (HEU) fuel cycle using uranium enriched to 93% U-235 and thorium to a 6-year, Medium Enriched Uranium (MEU) fuel cycle using uranium enriched to 20% U-235 and thorium, are described. The study shows that a transition from the

M. E. Fehrenbach; A. M. Baxter

1979-01-01

47

Modified Anchor Shaped Post Core Design for Primary Anterior Teeth  

PubMed Central

Restoring severely damaged primary anterior teeth is challenging to pedodontist. Many materials are tried as a post core but each one of them has its own drawbacks. This a case report describing a technique to restore severely damaged primary anterior teeth with a modified anchor shaped post. This technique is not only simple and inexpensive but also produces better retention. PMID:25379294

Rajesh, R.; Baroudi, Kusai; Reddy, K. Bala Kasi; Praveen, B. H.; Kumar, V. Sumanth; Amit, S.

2014-01-01

48

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

49

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

Microsoft Academic Search

In this paper the design of a Boiling Water Reactor (BWR) equilibrium core using thorium is presented; a heterogeneous blanket-seed core arrangement concept was adopted. The design was developed in three steps: in the first step two different assemblies were designed based on the integrated blanket-seed concept, they are the blanket-dummy assembly and the blanket-seed assembly. The integrated blanketseed concept

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

2004-01-01

50

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

Microsoft Academic Search

In this paper the design of a Boiling Water Reactor (BWR) equilibrium core using thorium is presented; a heterogeneous blanket-seed core arrangement concept was adopted. The design was developed in three steps: in the first step two different assemblies were designed based on the integrated blanket-seed concept, they are the blanket-dummy assembly and the blanket-seed assembly. The integrated blanket- seed

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

51

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

52

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

53

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

E-print Network

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 ...

Shirvan, Koroush

2013-01-01

54

Real-Time Operating System Hardware Extension Core for System-on-Chip Designs.  

E-print Network

??This thesis presents a real-time operating system hardware extension core which supports the integration of hardware accelerators into real-time system-on-chip designs as hardware tasks. The… (more)

Best, Joel

2013-01-01

55

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

E-print Network

Core Curriculum / 18 credits IS 6420 Database Theory and Design 3 IS 6410 Information Systems Analytics 3 IS 6571 IT Forensics 3 IS 6570 IT Security 3 ACCTG 6520 IT Risks and Controls 3 The MSIS program

Tipple, Brett

56

Interaction of the control system with core nuclear design for fast spectrum space power reactors  

NASA Astrophysics Data System (ADS)

The reactor control system and operating strategy are essential factors in assessing reactor reliability and safety. The control system and its mode of operation also exert major influences on mechanical design of core components and all aspects of nuclear design. This is especially true of reactors for space power applications because of the imposed requirements regarding compactness, minimum mass, and long term operational reliability without external intervention or maintenance. Generic features of the interaction between nuclear design and reactor control system design for fast spectrum space power reactors are outlined. Several basic control concepts were analyzed. These included ex-core control drums, in-core control rods, burnable poisons, dispersed poisons in the core, and movable fuel segments or regions. Cross sections for calculations were generated with MC sup 2 -2, and neutronics calculations were performed with the VIM Monte Carlo code, ONEDANT, and DIF3D.

Lell, R. M.; Hanan, N. A.

57

Designing a Core Curriculum. Proceedings of an Institute on Core Curriculum Design at Saint Joseph's College, Rensselaer, Indiana, June 3-8, 1979.  

ERIC Educational Resources Information Center

A report of the proceedings of an Institute on Core Curriculum Design, held in June, 1979 at Saint Joseph's College, Rensselaer, Indiana, is presented. Contents include: prefatory matter including the director's preface, the editor's preface, a list of participants, the schedule of the activities of the institute, the keynote address ("On Getting…

Nichols, John P., Ed.; Groppe, John D., Ed.

58

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

NASA Astrophysics Data System (ADS)

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

Kinoshita, Takahiko

59

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

60

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

61

Inductor Design Methods With Low-Permeability RF Core Materials  

E-print Network

This paper presents a design procedure for inductors based on low-permeability magnetic materials, for use in very high frequency power conversion. The proposed procedure offers an easy and fast way to compare different ...

Han, Yehui

62

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

63

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

64

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. 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

65

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

66

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

SciTech Connect

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

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

2012-07-01

67

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

Microsoft Academic Search

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

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

1997-01-01

68

Design and pilot evaluation of the RAH-66 Comanche Core AFCS  

NASA Technical Reports Server (NTRS)

This paper addresses the design and pilot evaluation of the Core Automatic Flight Control System (AFCS) for the Reconnaissance/Attack Helicopter (RAH-66) Comanche. During the period from November 1991 through February 1992, the RAH-66 Comanche control laws were evaluated through a structured pilot acceptance test using a motion base simulator. Design requirements, descriptions of the control law design, and handling qualities data collected from ADS-33 maneuvers are presented.

Fogler, Donald L., Jr.; Keller, James F.

1993-01-01

69

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

70

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

71

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

72

Design and Performance of South Ukraine Nuclear Power Plant Mixed Cores  

SciTech Connect

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

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

2011-09-24

73

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

74

The Design and Performance of IceCube DeepCore  

NASA Technical Reports Server (NTRS)

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

Stamatikos, M.

2012-01-01

75

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

76

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

77

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

78

Fusion-power-core design of a compact Reversed-Field Pinch Reactor (CRFPR)  

SciTech Connect

A conceptual design of a fusion power core (FPC, i.e., plasma chamber, first wall, blanket, shield, coils) based on a Reversed-Field Pinch (RFP) has been completed. After a brief statement of rationale and description of the reactor configuration, the FPC integration is described in terms of power balance, thermal-hydraulics, and mechanical design. The engineering versatility, promise, and problems of this high-power-density approach to fusion are addressed.

Copenhaver, C.; Battak, M.E.; Cappiello, C.; Chaffee, A.D.; Davidson, J.W.; Hayenson, R.L.; Krakowski, R.A.; Lujan, R.E.; Mynard, R.C.; Schnurr, N.M.

1985-07-01

79

Fusion-power-core design of a compact Reversed-Field Pinch Reactor (CRFPR)  

SciTech Connect

A conceptual design of a fusion power core (FPC, i.e., plasma chamber, first wall, blanket, shield, coils) based on a Reversed-Field Pinch (RFP) has been completed. After a brief statement of rationale and description of the reactor configuration, the FPC integration is described in terms of power balance, thermal-hydraulics, and mechanical design. The engineering versatility, promise, and problems of this high-power-density approach to fusion are addressed.

Copenhaver, C.; Schnurr, N.M.; Krakowski, R.A.; Hagenson, R.L.; Mynard, R.C.; Cappiello, C.; Lujan, R.E.; Davidson, J.W.; Chaffee, A.D.; Battat, M.E.

1985-01-01

80

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

2013-11-01

81

Designing a New Fuel for HFIR-Performance Parameters for LEU Core Configurations  

SciTech Connect

An engineering design study for a fuel that would enable the conversion of the High Flux Isotope Reactor from highly enriched uranium to low enriched uranium fuel is ongoing as part of an effort sponsored by the U.S. Department of Energy's National Nuclear Security Administration through the Global Threat Reduction Initiative. Given the unique fuel and core design and high power density of the reactor and the requirement that the impact of the fuel change on the core performance and operation be minimal, this conversion study presents a complex and challenging task, requiring improvements in the computational models currently used to support the operation of the reactor and development of new models that would take advantage of newly available simulation methods and tools. The computational models used to search for a fuel design that would meet the requirements for the conversion study and the results obtained with these models are presented and discussed. Estimates of relevant reactor performance parameters for the low enriched uranium fuel core are presented and compared to the corresponding data for the currently operating highly enriched uranium fuel core.

Ilas, Germina [ORNL; Primm, Trent [ORNL; Gehin, Jess C [ORNL

2009-01-01

82

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

SciTech Connect

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

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

2002-07-01

83

Multi-core fiber design and analysis: coupled-mode theory and coupled-power theory.  

PubMed

Coupled-mode and coupled-power theories are described for multi-core fiber design and analysis. First, in order to satisfy the law of power conservation, mode-coupling coefficients are redefined and then, closed-form power-coupling coefficients are derived based on exponential, Gaussian, and triangular autocorrelation functions. Using the coupled-mode and coupled-power theories, impacts of random phase-offsets and correlation lengths on crosstalk in multi-core fibers are investigated for the first time. The simulation results are in good agreement with the measurement results. Furthermore, from the simulation results obtained by both theories, it is confirmed that the reciprocity is satisfied in multi-core fibers. PMID:22274004

Koshiba, Masanori; Saitoh, Kunimasa; Takenaga, Katsuhiro; Matsuo, Shoichiro

2011-12-12

84

An optimized design of a dual-core photonic crystal fiber coupler  

NASA Astrophysics Data System (ADS)

An optical fiber coupler is a very important component in realizing all-fiber communication system. The appearance of dual-core photonic crystal fibers (PCFs) has enabled a new method of designing fiber coupler. Directional coupler based on the dual-core PCFs was investigated and shows intriguing properties, e.g., broadband coupling, the shorter coupling length, and polarized-mode coupling. However, the coupling bandwidth is the one of the most key properties due to the wavelength dependent of coupling efficiency for optical fiber coupler. In order to obtain the wavelength flattened response coupler with insensitive to deformation of air holes, in this paper an asymmetry dual-core PCF coupler with depressed-doped core is proposed and its coupling characteristics are also investigated by full-vector beam propagation method (BPM) in detail. The result of simulation shows that the coupling coefficient of 50%+/- 0.5% over a wide wavelength from 1.3?m to 1.7?m. Its coupling length is about 394?m, which is much shorter than that of other dual-core PCF couplers reported in literature. The fluctuation of coupling ratio is smaller than 5% with variation of the coupling length of 10%. We also demonstrate it could be more robust caused from the shorter coupling length. Furthermore, the mode field of the coupler is Gaussian-shape which means that additional insertion loss will not be introduced.

Xu, Feng; Tao, Dashi; Shi, Miaomiao; Jiang, Chao; Zhang, Bo; Shi, Xiaolong; Yu, Benli

2009-11-01

85

Design and fabrication of an asymmetric twin-core fiber directional coupler for gain-flattened EDFA  

Microsoft Academic Search

Fiber directional couplers made of highly asymmetric twin-cores (ATC), one of which is doped with erbium, are designed to achieve an inherently gain flattened erbium doped fiber amplifier (EDFA). The refractive index profiles of the fibers as well as the spacing between the two cores were carefully designed to achieve a targeted gain with low gain excursions across the C-band.

B. Nagarajua; M. Udeb; S. Trzesienb; B. Dussardierb; R. K. Varshneya; G. Monnom; W. Blanc; B. P. Pal

2011-01-01

86

Advanced Core Design And Fuel Management For Pebble-Bed Reactors  

SciTech Connect

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

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

2004-10-01

87

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

88

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

Microsoft Academic Search

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

Erika Cota; Luigi Carro; Marcelo Lubaszewski; Alex Orailoglu

2002-01-01

89

Accurate, scalable and informative design space exploration for large and sophisticated multi-core oriented architectures  

Microsoft Academic Search

Abstract—As microprocessors become more complex, early design space exploration plays an essential role in reducing the time to market and post-silicon surprises. The trend toward multi-\\/many- core processors will result in sophisticated large- scale architecture substrates (e.g. non-uniformly accessed caches interconnected by network-on-chip) that exhibit increasingly complex and heterogeneous behavior. While conventional analytical modeling techniques can be used to efficiently

Chang-Burm Cho; James Poe; Tao Li; Jingling Yuan

2009-01-01

90

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

SciTech Connect

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

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

2012-07-01

91

Prototypic design of the single-flux-quantum microprocessor, CORE1  

NASA Astrophysics Data System (ADS)

We have designed a prototype of a microprocessor based on single-flux-quantum logic. The microprocessor called CORE1 has seven instructions and represents the simplest implementation of our CORE (complexity-reduced) architecture concept. Both instructions and data are 8-bit-wide, bit-serial, and their bit operations are performed with 16 GHz local clocks. The microprocessor is composed of a controller, a 5-bit program counter, an 8-bit instruction register, two 8-bit registers and a bit-serial ALU. We put together these components and some substitute shift registers for a memory into one microprocessor made up of 1301 cells, 4999 Josephson junctions. Using floor plans, both block-level and cell-level simulation techniques, we completed the timing design of all signal lines between the components. The designed CORE1 chip executes each instruction in six system clocks and we estimated its performance and power consumption at 167 million instructions per second and 1.6 mW, respectively.

Tanaka, M.; Matsuzaki, F.; Kondo, T.; Nakajima, N.; Yamanashi, Y.; Terai, H.; Yorozu, S.; Yoshikawa, N.; Fujimaki, A.; Hayakawa, H.

2003-12-01

92

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

93

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

94

Design of bus-on-chip core for micro-satellite avionics  

NASA Astrophysics Data System (ADS)

This paper discusses a layout of bus-on-chip core referring to SoC thinking which is composed of six sections based on a physical chip of FPGA: multi-Processor cache coherence unit, external bus control module, TT&C module, Ethernet Mac interface, EDAC/DMA module, and AMBA bridges. Multi-processor cache coherence unit, as a key part of the bus core, is used to serve the rapid parallel computing by means of the breakthrough of write/read speed of EMS memory and enhances the reliability of OBC with the service of supporting the hot standby of redundancy and the reconfiguration of fault-tolerance. External bus control module is made to support the PnP of external components applying varieties of buses, which is designed by means of soft-core in order to adapt the variation of macro-design and improve the flexibility of external application. TT&C module is the interface of subsystems of telemetry, telecommand and communication, which involves the protocols of HDLC. Ethernet Mac interface based on TCP/IP acts as the access of ISL for formation flying, constellation, etc. EDAC/DMA module mainly manages the data exchange between AMBA bus and RAM, and assigns DMA for the payloads.

Liu, Youjun; You, Zheng; Li, Bin; Zhang, Xiangqi; Meng, Ziyang

2007-11-01

95

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

96

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

SciTech Connect

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

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

2004-10-06

97

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

98

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

SciTech Connect

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

B. Boer; A. M. Ougouag

2010-05-01

99

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

Microsoft Academic Search

The purpose of this work was to optimize the process parameters required for the production of spray-dried oily core nanocapsules\\u000a (NCs) with targeted size and drug yield using a two-level four-factor fractional factorial experimental design (FFED). The\\u000a coded process parameters chosen were inlet temperature (X\\u000a 1), feed flow rate (X\\u000a 2), atomizing air flow (X\\u000a 3), and aspiration rate (X

Tao Zhang; Bi-Botti C. Youan

2010-01-01

100

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

101

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

102

Gigawatt, Closed Cycle, Vapor Core-Mhd Space Power System Conceptual Design Study  

NASA Astrophysics Data System (ADS)

A conceptual design study for a closed cycle gigawatt electric space power system has been conducted. The closed cycle static operation reduces power system interaction effects upon the space craft. This system utilizes a very high temperature (5500 K) plasma core reactor and a magnetohydrodynamic (MHD) power conversion subsystem to provide a power density of about 8 kWe/kg (0.13 kg/kWe) for several kilo-seconds. Uranium vapor is the fuel. Candidate working fluids are metal vapors such as lithium or calcium. The system is based on a Rankine cycle to minimize the electromagnetic pumping power requirement. The fission fragment induced nonequilibrium ionization in the plasma in the MHD power duct provides the plasma electric conductivity for gigawatt power generation. Waste heat is rejected utilizing lithium heat pipes at temperatures just below 2000 K, thus minimizing the radiator area requirement. Key technology issues are identified, including the containment of the 5500 K 'sun-liken plasma at 4 to 0 MPa In a reflector moderated, gas/vapor filled cavity core reactor. A promising scheme to protect the refractory metal reactor inner wall is presented, together with a heating load analysis in the wall. This scheme utilizes an ablating film of liquid lithium/calcium that evaporates into the cavity core to become the working fluid of the cycle.

Wetch, Joseph R.; Rhee, Hyop S.; Koester, J. Kent; Goodman, Julius; Maya, Issac

1988-04-01

103

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

104

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

105

Design of dual core resonant leaky fiber for inherent gain flattening of S-band EDFA  

NASA Astrophysics Data System (ADS)

We present a novel co-axial dual core resonant leaky fiber (DCRLF) design for inherent gain equalization of S-band erbium doped fiber amplifier (EDFA). Spectral leakage loss variation of the structure has been utilized to suppress the amplified spontaneous emission (ASE) in the C-band and to achieve inherent gain flattening in the S-band of an EDFA. We show 19 dB flat gain with +/- 1.1 dB ripple over 30 nm bandwidth (1490-1520 nm) and 20 dB flat gain with +/- 2.1 dB ripple over 40 nm bandwidth (1485-1525 nm). We have also carried out a detailed tolerance study of the designed Sband EDFA with respect to the outer cladding parameters.

Kamakshi, Koppole; Rastogi, Vipul

2011-05-01

106

Reactor core design and modeling of the MIT research reactor for conversion to LEU  

SciTech Connect

Feasibility design studies for conversion of the MIT Research Reactor (MITR) to LEU are described. Because the reactor fuel has a rhombic cross section, a special input processor was created in order to model the reactor in great detail with the REBUS-PC diffusion theory code, in 3D (triangular-z) geometry. Comparisons are made of fuel assembly power distributions and control blade worth vs. axial position, between REBUS-PC results and Monte Carlo predictions from the MCNP code. Results for the original HEU core at zero burnup are also compared with measurement. These two analysis methods showed remarkable agreement. Ongoing fuel cycle studies are summarized. A status report will be given as to results thus far that affect key design decisions. Future work plans and schedules to achieve completion of the conversion are presented. (author)

Newton, Thomas H. Jr. [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, 138 Albany St., Cambridge, MA 02139 (United States); Olson, Arne P.; Stillman, John A. [RERTR Program, Argonne National Laboratory, Argonne, IL 60439 (United States)

2008-07-15

107

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

SciTech Connect

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, corners, and other sections where excessive power would create significant loss to thermal-hydraulic margins.This work examined a number of physics and core safety analysis parameters that impact the operation and safety of power reactors. Such parameters as moderator coefficients of reactivity, Doppler coefficients, soluble boron worth, control rod worth, prompt neutron lifetime, and delayed-neutron fractions were considered. These in turn were used to examine reactor behavior during a number of operational conditions, transients, and accidents. Such conditions as shutdown from power with one rod stuck out, steam-line break accident, feedwater line break, loss of coolant flow, locked rotor accidents, control rod ejection accidents, and anticipated transients without scram (ATWSs) were examined.The analysis of selected reactor transients demonstrated that it is feasible to license and safely operate a reactor fueled with plutonium-thorium blended fuel. In most cases analyzed, the thorium mixture had less-severe consequences than those for a core comprising low-enriched uranium fuel. In the analyzed cases where the consequences were more severe, they were still within acceptable limits. The ATWS accident condition requires more analysis.

Dziadosz, David; Ake, Timothy N.; Saglam, Mehmet; Sapyta, Joe J. [Framatome ANP, Inc. (France)

2004-07-15

108

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

109

Optimal design at inner core of the shaped pyramidal truss structure  

SciTech Connect

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

Lee, Sung-Uk; Yang, Dong-Yol [Department of Mechanical Engineering, KAIST 291 Daehak-ro (373-1 Guseong-dong), Yuseong-gu, Dae-jeon, 305-701 (Korea, Republic of)

2013-12-16

110

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

Microsoft Academic Search

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

K. Qiu; W. Zhang; P. Duysinx

111

America's Next Great Ship: Space Launch System Core Stage Transitioning from Design to Manufacturing  

NASA Technical Reports Server (NTRS)

The Space Launch System (SLS) Program is essential to achieving the Nation's and NASA's goal of human exploration and scientific investigation of the solar system. As a multi-element program with emphasis on safety, affordability, and sustainability, SLS is becoming America's next great ship of exploration. The SLS Core Stage includes avionics, main propulsion system, pressure vessels, thrust vector control, and structures. Boeing manufactures and assembles the SLS core stage at the Michoud Assembly Facility (MAF) in New Orleans, LA, a historical production center for Saturn V and Space Shuttle programs. As the transition from design to manufacturing progresses, the importance of a well-executed manufacturing, assembly, and operation (MA&O) plan is crucial to meeting performance objectives. Boeing employs classic techniques such as critical path analysis and facility requirements definition as well as innovative approaches such as Constraint Based Scheduling (CBS) and Cirtical Chain Project Management (CCPM) theory to provide a comprehensive suite of project management tools to manage the health of the baseline plan on both a macro (overall project) and micro level (factory areas). These tools coordinate data from multiple business systems and provide a robust network to support Material & Capacity Requirements Planning (MRP/CRP) and priorities. Coupled with these tools and a highly skilled workforce, Boeing is orchestrating the parallel buildup of five major sub assemblies throughout the factory. Boeing and NASA are transforming MAF to host state of the art processes, equipment and tooling, the most prominent of which is the Vertical Assembly Center (VAC), the largest weld tool in the world. In concert, a global supply chain is delivering a range of structural elements and component parts necessary to enable an on-time delivery of the integrated Core Stage. SLS is on plan to launch humanity into the next phase of space exploration.

Birkenstock, Benjamin; Kauer, Roy

2014-01-01

112

Chemical and colloidal stability of carboxylated core-shell magnetite nanoparticles designed for biomedical applications.  

PubMed

Despite the large efforts to prepare super paramagnetic iron oxide nanoparticles (MNPs) for biomedical applications, the number of FDA or EMA approved formulations is few. It is not known commonly that the approved formulations in many instances have already been withdrawn or discontinued by the producers; at present, hardly any approved formulations are produced and marketed. Literature survey reveals that there is a lack for a commonly accepted physicochemical practice in designing and qualifying formulations before they enter in vitro and in vivo biological testing. Such a standard procedure would exclude inadequate formulations from clinical trials thus improving their outcome. Here we present a straightforward route to assess eligibility of carboxylated MNPs for biomedical tests applied for a series of our core-shell products, i.e., citric acid, gallic acid, poly(acrylic acid) and poly(acrylic acid-co-maleic acid) coated MNPs. The discussion is based on physicochemical studies (carboxylate adsorption/desorption, FTIR-ATR, iron dissolution, zeta potential, particle size, coagulation kinetics and magnetization measurements) and involves in vitro and in vivo tests. Our procedure can serve as an example to construct adequate physico-chemical selection strategies for preparation of other types of core-shell nanoparticles as well. PMID:23857054

Szekeres, Márta; Tóth, Ildikó Y; Illés, Erzsébet; Hajdú, Angéla; Zupkó, István; Farkas, Katalin; Oszlánczi, Gábor; Tiszlavicz, László; Tombácz, Etelka

2013-01-01

113

Chemical and Colloidal Stability of Carboxylated Core-Shell Magnetite Nanoparticles Designed for Biomedical Applications  

PubMed Central

Despite the large efforts to prepare super paramagnetic iron oxide nanoparticles (MNPs) for biomedical applications, the number of FDA or EMA approved formulations is few. It is not known commonly that the approved formulations in many instances have already been withdrawn or discontinued by the producers; at present, hardly any approved formulations are produced and marketed. Literature survey reveals that there is a lack for a commonly accepted physicochemical practice in designing and qualifying formulations before they enter in vitro and in vivo biological testing. Such a standard procedure would exclude inadequate formulations from clinical trials thus improving their outcome. Here we present a straightforward route to assess eligibility of carboxylated MNPs for biomedical tests applied for a series of our core-shell products, i.e., citric acid, gallic acid, poly(acrylic acid) and poly(acrylic acid-co-maleic acid) coated MNPs. The discussion is based on physicochemical studies (carboxylate adsorption/desorption, FTIR-ATR, iron dissolution, zeta potential, particle size, coagulation kinetics and magnetization measurements) and involves in vitro and in vivo tests. Our procedure can serve as an example to construct adequate physico-chemical selection strategies for preparation of other types of core-shell nanoparticles as well. PMID:23857054

Szekeres, Marta; Toth, Ildiko Y.; Illes, Erzsebet; Hajdu, Angela; Zupko, Istvan; Farkas, Katalin; Oszlanczi, Gabor; Tiszlavicz, Laszlo; Tombacz, Etelka

2013-01-01

114

Novel design of dual-core microstructured fiber with enhanced longitudinal strain sensitivity  

NASA Astrophysics Data System (ADS)

Constantly refined technology of manufacturing increasingly complex photonic crystal fibers (PCF) leads to new optical fiber sensor concepts. The ways of enhancing the influence of external factors (such as hydrostatic pressure, temperature, acceleration) on the fiber propagating conditions are commonly investigated in literature. On the other hand longitudinal strain analysis, due to the calculation difficulties caused by the three dimensional computation, are somehow neglected. In this paper we show results of such a 3D numerical simulation and report methods of tuning the fiber strain sensitivity by changing the fiber microstructure and core doping level. Furthermore our approach allows to control whether the modes' effective refractive index is increasing or decreasing with strain, with the possibility of achieving zero strain sensitivity with specific fiber geometries. The presented numerical analysis is compared with experimental results of the fabricated fibers characterization. Basing on the aforementioned methodology we propose a novel dual-core fiber design with significantly increased sensitivity to longitudinal strain for optical fiber sensor applications. Furthermore the reported fiber satisfies all conditions necessary for commercial applications like good mode matching with standard single-mode fiber, low confinement loss and ease of manufacturing with the stack-and-draw technique. Such fiber may serve as an integrated Mach-Zehnder interferometer when highly coherent source is used. With the optimization of single mode transmission to 850 nm, we propose a VCSEL source to be used in order to achieve a low-cost, reliable and compact strain sensing transducer.

Szostkiewicz, Lukasz; Tenderenda, T.; Napierala, M.; Szyma?ski, M.; Murawski, M.; Mergo, P.; Lesiak, P.; Marc, P.; Jaroszewicz, L. R.; Nasilowski, T.

2014-05-01

115

Design and fabrication of an asymmetric twin-core fiber directional coupler for gain-flattened EDFA  

E-print Network

of such an inherently gain flattened EDFA by the MCVD fiber preform fabrication process, the design had to be modified from the two assembled preforms. Preliminary characterization of the fabricated fiber shows filteringDesign and fabrication of an asymmetric twin-core fiber directional coupler for gain-flattened EDFA

Paris-Sud XI, Université de

116

Design and fabrication of an asymmetric twin-core fiber directional coupler for gain-flattened EDFA  

NASA Astrophysics Data System (ADS)

Fiber directional couplers made of highly asymmetric twin-cores (ATC), one of which is doped with erbium, are designed to achieve an inherently gain flattened erbium doped fiber amplifier (EDFA). The refractive index profiles of the fibers as well as the spacing between the two cores were carefully designed to achieve a targeted gain with low gain excursions across the C-band. One of the designs yielded a theoretical median gain ~ 38 dB with an excursion within +/-1 dB. In order to suite fabrication of such an inherently gain flattened EDFA by the MCVD fiber preform fabrication process, the design had to be modified and a more modest target of about 20 dB was set with excursion below +/- 1.5 dB for metro-centric applications. It involved preparation of two independent preforms, which required selective polishing of the cladding from one side by a certain amount to meet the required nominal separation between the two cores set at the design stage of the fiber. Several intricate operations were required to implement the fiber drawing step from the two assembled preforms. Preliminary characterization of the fabricated fiber shows filtering of ASE peak through selective wavelength coupling from Er-doped core to un-doped core.

Nagaraju, B.; Ude, M.; Trzésien, S.; Dussardier, B.; Varshney, R. K.; Monnom, G.; Blanc, W.; Pal, B. P.

2011-12-01

117

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

118

Design and analysis of a refractive index sensor based on dual-core large-mode-area fiber  

NASA Astrophysics Data System (ADS)

We present a novel co-axial dual core large-mode-area (LMA) fiber design for refractive index sensing. In a dual-core fiber there is resonant coupling between the two cores, which is strongly affected by the refractive index (RI) of the outermost region. The transmittance of the fiber, therefore, varies sharply with the refractive index of surrounding medium. This characteristic of the proposed structure has been utilized to design a RI sensor. We have analyzed the structure by using the transfer matrix method. Our numerical results show that the proposed sensor is highly sensitive with the resolution of 2.0 × 10-6 around nex = 1.44376. Effect of design parameters on sensitivity of the proposed sensor has also been investigated.

Kamakshi, Koppole; Rastogi, Vipul; Kumar, Ajeet

2013-08-01

119

High accuracy modeling for advanced nuclear reactor core designs using Monte Carlo based coupled calculations  

NASA Astrophysics Data System (ADS)

The main objective of this PhD research is to develop a high accuracy modeling tool using a Monte Carlo based coupled system. The presented research comprises the development of models to include the thermal-hydraulic feedback to the Monte Carlo method and speed-up mechanisms to accelerate the Monte Carlo criticality calculation. Presently, deterministic codes based on the diffusion approximation of the Boltzmann transport equation, coupled with channel-based (or sub-channel based) thermal-hydraulic codes, carry out the three-dimensional (3-D) reactor core calculations of the Light Water Reactors (LWRs). These deterministic codes utilize nuclear homogenized data (normally over large spatial zones, consisting of fuel assembly or parts of fuel assembly, and in the best case, over small spatial zones, consisting of pin cell), which is functionalized in terms of thermal-hydraulic feedback parameters (in the form of off-line pre-generated cross-section libraries). High accuracy modeling is required for advanced nuclear reactor core designs that present increased geometry complexity and material heterogeneity. Such high-fidelity methods take advantage of the recent progress in computation technology and coupled neutron transport solutions with thermal-hydraulic feedback models on pin or even on sub-pin level (in terms of spatial scale). The continuous energy Monte Carlo method is well suited for solving such core environments with the detailed representation of the complicated 3-D problem. The major advantages of the Monte Carlo method over the deterministic methods are the continuous energy treatment and the exact 3-D geometry modeling. However, the Monte Carlo method involves vast computational time. The interest in Monte Carlo methods has increased thanks to the improvements of the capabilities of high performance computers. Coupled Monte-Carlo calculations can serve as reference solutions for verifying high-fidelity coupled deterministic neutron transport methods with detailed and accurate thermal-hydraulic models. The development of such reference high-fidelity coupled multi-physics scheme is described in this dissertation on the basis of MCNP5, NEM, NJOY and COBRA-TF (CTF) computer codes. This work presents results from studies performed and implemented at the Pennsylvania State University (PSU) on both accelerating Monte Carlo criticality calculations by using hybrid nodal diffusion Monte Carlo schemes and thermal-hydraulic feedback modeling in Monte Carlo core calculations. The hybrid MCNP5/CTF/NEM/NJOY coupled code system is proposed and developed in this dissertation work. The hybrid coupled code system contains a special interface developed to update the required MCNP5 input changes to account for dimension and density changes provided by the thermal-hydraulics feedback module. The interface has also been developed to extract the flux and reaction rates calculated by MCNP5 to later transform the data into the power feedback needed by CTF (axial and radial peaking factors). The interface is contained in a master program that controls the flow of the calculations. Both feedback modules (thermal-hydraulic and power subroutines) use a common internal interface to further accelerate the data exchange. One of the most important steps to correctly include the thermal hydraulic feedback into MCNP5 calculations begins with temperature dependent cross section libraries. If the cross sections used for the calculations are not at the correct temperature, the temperature feedback cannot be included into MCNP5 (referred to the effect of temperature on cross sections: Doppler boarding of resolve and unresolved resonances, thermal scattering and elastic scattering). The only method of considering the temperature effects on cross sections is through the generation (or as introduced in this dissertation through a novel interpolation mechanism) of continuous energy temperature-dependent cross section libraries. An automated methodology for generation of continuous energy temperature-dependent cross section libraries has been developed

Espel, Federico Puente

120

Preliminary scoping safety analyses of the limiting design basis protected accidents for the Fast Flux Test Facility tritium production core  

SciTech Connect

The SAS4A/SASSYS-l computer code is used to perform a series of analyses for the limiting protected design basis transient events given a representative tritium and medical isotope production core design proposed for the Fast Flux Test Facility. The FFTF tritium and isotope production mission will require a different core loading which features higher enrichment fuel, tritium targets, and medical isotope production assemblies. Changes in several key core parameters, such as the Doppler coefficient and delayed neutron fraction will affect the transient response of the reactor. Both reactivity insertion and reduction of heat removal events were analyzed. The analysis methods and modeling assumptions are described. Results of the analyses and comparison against fuel pin performance criteria are presented to provide quantification that the plant protection system is adequate to maintain the necessary safety margins and assure cladding integrity.

Heard, F.J.

1997-11-19

121

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

SciTech Connect

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

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

2012-07-01

122

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

123

Concrete core activation and suspended ceilings: Designing for comfort, energy efficiency, and good acoustics.  

PubMed

The trend to design energy-efficient buildings continues. Both legislation as sustainability assessment methods have increased the popularity of thermally activated concrete slabs. It is a way to use low temperature heating and high temperature cooling which makes it very suited for the use in low energy systems. The efficiency of these systems relate to the surface area, often the ceiling area. Exactly that surface was already the domain for the sound absorbing ceiling. So in new buildings with high energy performance due to concrete core activation, the sound absorption is often banned, resulting in very poor acoustics. The use of open, sound absorbing ceilings will have an influence on the thermal capacity of the concrete slabs, However, little is known about this effect. To investigate the effect of open ceilings to both the cooling capacity as the sound absorption, theoretical/empirical models have been made to estimate the effect on the cooling capacity and the sound absorption. The method is also tested in a field situation. It turns out that optimization is possible, with both cooling capacity as sound absorption around 70% of the maximum. PMID:25235705

Vercammen, Martijn; Peperkamp, Hanneke

2014-04-01

124

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

Microsoft Academic Search

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

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

2005-01-01

125

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

ERIC Educational Resources Information Center

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

Moshier, Kenneth

126

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

ERIC Educational Resources Information Center

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

Hume, Anne; Berry, Amanda

2013-01-01

127

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

128

Design of metallic textile core sandwich panels F.W. Zok *, H.J. Rathbun, Z. Wei, A.G. Evans  

E-print Network

Design of metallic textile core sandwich panels F.W. Zok *, H.J. Rathbun, Z. Wei, A.G. Evans-5050, USA Received 3 March 2003 Abstract Metallic sandwich panels with textile cores have been analyzed are made with competing concepts, especially honeycomb and truss core systems. It is demonstrated that all

Zok, Frank

129

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

130

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

SciTech Connect

Sodium-cooled mixed-oxide core design studies are performed with a target burnup of 150 GWd/t and possible measures against the recriticality issues in core disruptive accidents. Four types of core are compared from the viewpoints of core performance and reliability. Results show that all the types of core satisfy the target and that a homogeneous core with an axial blanket partial elimination subassembly is the superior concept, although experimental demonstration is required of molten fuel motion for mitigation of recriticality following fuel melting and loss of fuel pin integrity.

Mizuno, Tomoyasu; Niwa, Hajime [Japan Nuclear Cycle Development Institute (Japan)

2004-05-15

131

SAS3D analysis of unprotected loss-of-flow transients for 1200MW(electric) liquid-metal fast breeder reactor homogeneous and heterogeneous core designs  

Microsoft Academic Search

A safety comparison was made for two 1200-MW(electric) liquid-metal fast breeder reactor cores with homogeneous and heterogeneous fuel arrangements, respectively. The two cores were conceptually designed to be identical except for those parameters affected by different fuel arrangements. The comparison was limited to the issue of initiating phase energetics in the hypothetical core disruptive accident. Both cores were assumed to

T. A. Shih; M. I. Temme

1978-01-01

132

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

PubMed Central

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

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

2013-01-01

133

Design of single-mode large-mode area bandgap fibre with microstructured-core  

NASA Astrophysics Data System (ADS)

Tailoring the modal characteristics of all-solid photonic bandgap fibre by the inclusion of low-index rods in the fibre core is investigated. By lowering the core index of the fibre, the high-order modes in the fibre can be shifted to the border of the bandgap, as a result, single-mode operation in large-mode area bandgap fibre can be realized without bending the fibre. In addition, large-mode area and single-mode operation in the all-solid microstructured-core bandgap fibre can be achieved by bending the fibre at a wide bending radius range.

Chen, Ming-Yang; Gong, Tian-Yi; Gao, Yong-Feng; Zhou, Jun

2014-11-01

134

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

135

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

PubMed

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

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

2009-02-16

136

Biomechanical evaluation of bending strength of spinal pedicle screws, including cylindrical, conical, dual core and double dual core designs using numerical simulations and mechanical tests.  

PubMed

Pedicle screws are used for treating several types of spinal injuries. Although several commercial versions are presently available, they are mostly either fully cylindrical or fully conical. In this study, the bending strengths of seven types of commercial pedicle screws and a newly designed double dual core screw were evaluated by finite element analyses and biomechanical tests. All the screws had an outer diameter of 7 mm, and the biomechanical test consisted of a cantilever bending test in which a vertical point load was applied using a level arm of 45 mm. The boundary and loading conditions of the biomechanical tests were applied to the model used for the finite element analyses. The results showed that only the conical screws with fixed outer diameter and the new double dual core screw could withstand 1,000,000 cycles of a 50-500 N cyclic load. The new screw, however, exhibited lower stiffness than the conical screw, indicating that it could afford patients more flexible movements. Moreover, the new screw produced a level of stability comparable to that of the conical screw, and it was also significantly stronger than the other screws. The finite element analysis further revealed that the point of maximum tensile stress in the screw model was comparable to the point at which fracture occurred during the fatigue test. PMID:25060212

Amaritsakul, Yongyut; Chao, Ching-Kong; Lin, Jinn

2014-09-01

137

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

PubMed

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

Perez, Roman A; Kim, Hae-Won

2013-04-01

138

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

139

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

SciTech Connect

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

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

1980-01-01

140

Design of a compact polarization splitter based on the dual-elliptical-core photonic crystal fiber  

NASA Astrophysics Data System (ADS)

We propose a compact polarization splitter based on dual-elliptical-core photonic crystal fiber. Two elliptical cores are introduced to increase the difference of effective index between x-polarized and y-polarized mode and three elliptical modulation air holes are used to control the power transfer between the two cores. By optimizing the structure parameters, the length of the polarization splitter is distinctly shortened. Numerical results demonstrate that the compact splitter has the length of 775 ?m and up to 50 dB extinction ratio at the central wavelength of 1.55 ?m. The corresponding bandwidth of 32 nm could be achieved from the wavelength of 1.534-1.566 ?m with the extinction ratio over 20 dB

Sheng, Zhufeng; Wang, Jiasheng; Feng, Ruijuan

2014-11-01

141

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

Microsoft Academic Search

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

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

2011-01-01

142

Core design study on CANDU-SCWR with 3D neutronics\\/thermal-hydraulics coupling  

Microsoft Academic Search

Using separated heavy water as moderator and supercritical water (SCW) as coolant introduces challenge for CANDU-SCWR to get a negative coolant void reactivity (CVR), due to which the moderator thickness of the fuel channel is optimized in this paper. When SCW flows through the core, there is a rapid variation in SCW density, which is directly related to the neutron

Ping Yang; Liangzhi Cao; Hongchun Wu; Changhui Wang

143

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

144

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

NASA Astrophysics Data System (ADS)

An operating mode with a very high confinement core like the VH-mode but a very low power flow to the divertor plates and low edge particle confinement like an L-mode would be beneficial. For a large tokamak like the proposed ITER, the power density at the separatrix is not that far above the scaled H-mode power threshold so not much of the power can be radiated inside the separatrix without causing a return to L-mode. The thicker scrape-off layer of an L-mode increases the radiating volume of the scrape-off layer and helps shield impurities from the core. This is especially important if the first wall is metallic. In this paper an H-mode transport model based on 0741-3335/38/8/055/img6 velocity shear suppression of turbulence will be used to show that it is possible to have a strongly radiating mantle near the separatrix, which keeps the edge in L-mode, while having a VH-mode core with a broad region of suppressed turbulence. The existing results of enhanced L-mode confinement during impurity injection on a number of tokamaks will be surveyed. We will identify the operating conditions which will most likely result in further improvement of the core confinement by control of the heating, fuelling, and torque profiles.

Staebler, G. M.; Hinton, F. L.; Wiley, J. C.

1996-08-01

145

Possible Methods to Estimate Core Location in a Beyond-Design-Basis Accident at a GE BWR with a Mark I Containment Stucture  

SciTech Connect

It is difficult to track to the location of a melted core in a GE BWR with Mark I containment during a beyond-design-basis accident. The Cooper Nuclear Station provided a baseline of normal material distributions and shielding configurations for the GE BWR with Mark I containment. Starting with source terms for a design-basis accident, methods and remote observation points were investigated to allow tracking of a melted core during a beyond-design-basis accident. The design of the GE BWR with Mark-I containment highlights an amazing poverty of expectations regarding a common mode failure of all reactor core cooling systems resulting in a beyond-design-basis accident from the simple loss of electric power. This design is shown in Figure 1. The station blackout accident scenario has been consistently identified as the leading contributor to calculated probabilities for core damage. While NRC-approved models and calculations provide guidance for indirect methods to assess core damage during a beyond-design-basis loss-of-coolant accident (LOCA), there appears to be no established method to track the location of the core directly should the LOCA include a degree of fuel melt. We came to the conclusion that - starting with detailed calculations which estimate the release and movement of gaseous and soluble fission products from the fuel - selected dose readings in specific rooms of the reactor building should allow the location of the core to be verified.

Walston, S; Rowland, M; Campbell, K

2011-07-27

146

ABWR-II Core Design with Spectral Shift Rods for Operation with All Control Rods Withdrawn  

SciTech Connect

An innovative reactor core concept applying spectral shift rods (SSRs) is proposed to improve the plant economy and the operability of the 1700-MW(electric) Advanced Boiling Water Reactor II (ABWR-II). The SSR is a new type of water rod in which a water level is naturally developed during operation and changed according to the coolant flow rate through the channel. By taking advantage of the large size of the ABWR-II bundle, the enhanced spectral shift operation by eight SSRs allows operation of the ABWR-II with all control rods withdrawn. In addition, the uranium-saving factor of 6 to 7% relative to the reference ABWR-II core with conventional water rods can be expected due to the greater effect of spectral shift. The combination of these advantages means the ABWR-II with SSRs should be an attractive alternative for the next-generation nuclear reactor.

Moriwaki, Masanao [Hitachi, Ltd. (Japan); Aoyama, Motoo [Hitachi, Ltd. (Japan); Anegawa, Takafumi [Tokyo Electric Power Company (Japan); Okada, Hiroyuki [Tokyo Electric Power Company (Japan); Sakurada, Koichi [Toshiba Corporation (Japan); Tanabe, Akira [Global Nuclear Fuel-Japan Company, Ltd. (Japan)

2004-03-15

147

Conceptual core design of Advanced Recycling Reactor based on mature technologies  

Microsoft Academic Search

This paper presents about comprehensive investigations into Advanced Recycling Reactor (ARR) based on existing and\\/or mature technologies (called “Early ARR”), aiming transuranics (TRU) burning and considering harmonization of TRU burning capability, technology readiness, economy and safety. The ARR is a 500MWe (1180MWth) oxide fueled sodium cooled fast reactor, which the low core height of 70cm and the large structure volume

Kazumi Ikeda; Kim O. Stein; Wataru Nakazato; Makoto Mito

2011-01-01

148

Embedded Software-Based Self-Test for Programmable Core-Based Designs  

Microsoft Academic Search

At-speed testing of high-speed circuits is becoming increasingly difficult with external testers. Therefore, empowering the chip to test itself seems like a natural solution. Hardware-based self- testing techniques have limitations due to performance and area overhead as well as problems caused by application of non-functional patterns. Another possible solution is software-based self-testing where the programmable cores are used for on-chip

Angela Krstic; Wei-cheng Lai; Kwang-ting Cheng; Li Chen; Sujit Dey

2002-01-01

149

Design and characterization of large-core optical fiber for Light Peak applications  

NASA Astrophysics Data System (ADS)

Bandwidth demand for transferring data among different consumer electronic products is increasing rapidly. Due to issues of high propagation loss, electromagnetic interference, and limited bandwidth-distance product of the present copper-based electrical cables, consumer electronic devices may not provide the bandwidth required for future high-capacity applications. The Intel Corporation has proposed Light Peak technology, allowing data transfer between electronic devices at 10 Gb/s in optical domain. To establish a reliable Light Peak connection, robust optical fiber is highly required. In this paper, we discuss the fabrication and characterization of a new type of 80-?m large-core optical fiber. We perform 10 Gb/s bit-error-rate measurements using 850 and 1550-nm transceivers. The results show that even though we have enlarged the fiber core diameter by 60% (from 50 to 80 ?m) in order to increase the laser-to-fiber alignment tolerance, transmission bandwidth and distance required by Light Peak can still be achieved in this new type of large-core optical fiber.

Chow, Chi-Wai; Yeh, Chien-Hung; Yang, Ling-Gang; Sung, Jiun-Yu; Huang, Sung-Ping; Pan, Ci-Ling; Chou, Gary

2012-01-01

150

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

SciTech Connect

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

Burns, T.D. Jr.

1996-05-01

151

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

152

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

ERIC Educational Resources Information Center

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

Miller, Daniel R.; And Others

153

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

E-print Network

birevit 'fer testing or fo'r come other applioation, ainoe na I" ' I information on the, ohiraoteristloshand type of sore uasd are t , 'given or no iuch core ia'available. The number. -cf . turne in'd' burient ratings af?. the winding?. ars, seldom...:::eetpat @alta@a ia developed. . when the, swltoh'. esrrant is tamed off' it is desirable to cake the "on" peri'od of the switnh cwrrent aa snail as possible and still obtain full eeitshing of the flex~ This sill elise the highest possible oonversion tate...

Hughes, Robert William

2012-06-07

154

Designing truly one-sided MPI2 RMA intra-node communication on multi-core systems  

Microsoft Academic Search

The increasing popularity of multi-core processors has made MPI intra-node communication, including the intra-node RMA (Remote\\u000a Memory Access) communication, a critical component in high performance computing. MPI-2 RMA model includes one-sided data\\u000a transfer and synchronization operations. Existing designs in popularly used MPI stacks do not provide truly one-sided intra-node\\u000a RMA communication. They are built on top of two-sided send-receive operations,

Ping Lai; Sayantan Sur; Dhabaleswar K. Panda

2010-01-01

155

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

NASA Astrophysics Data System (ADS)

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.

2010-06-01

156

The evolution and application of VXIbus common core based ATS design  

Microsoft Academic Search

This paper looks at one system integrator's experiences of VXIbus ATS design over the past decade. A number of specific successful ATS implementations, for factory and depot, fixed installation and deployable, are examined. The evolution of the overall ATS designs detailing influencing factors, differences, and common aspects are highlighted. The benefits, to the through life support of ATSs, of a

John Paul

1998-01-01

157

Staying True to the Core: Designing the Future Academic Library Experience  

ERIC Educational Resources Information Center

In 2014, the practice of user experience design in academic libraries continues to evolve. It is typically applied in the context of interactions with digital interfaces. Some academic librarians are applying user experience approaches more broadly to design both environments and services with human-centered strategies. As the competition for the…

Bell, Steven J.

2014-01-01

158

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

159

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. PMID:22685582

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

2012-01-01

160

Design, Syntheses, and Characterization of a Sterically Encumbered Dioxo Molybdenum (VI) Core  

PubMed Central

Dioxo-MoVI complexes of general formula Tp*MoO2(p-SC6H4Dn) (6a-6c) (where Tp* = hydrotris(3,5-dimethyl-pyrazol-1-yl)borate and Dn= dendritic unit) have been synthesized and characterized by spectroscopy and mass spectrometry. 1H NMR spectra of the metal complexes indicate that the Cs local symmetry about the metal core does not change by the incorporation of dendritic functionality at the thiophenolato ring. Electrochemical data show ?20 mV change in the redox potential in the complexes with dendritic ligands suggesting a very small perturbation in the redox orbital, which is also supported by small changes in the electronic spectra. The peak-to peak separation (?Ep) increases from 125 mV in 6(a) to 240 mV in 6(c), suggesting sluggish electron transfer in molecules with larger dendritic ligands. PMID:18425212

Sengar, Raghvendra S.; Basu, Partha

2007-01-01

161

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

162

Impulse-Response Analysis of Toroidal Core Distribution Transformers for Dielectric Design  

Microsoft Academic Search

Toroidal transformers are currently used only in low- voltage applications. There is no published experience for toroidal transformer design at distribution-level voltages. This paper ex- ploresthelightningimpulseresponseoftoroidaldistributiontrans- formers in order to obtain a dielectric design able to withstand standardized impulse tests. Three-dimensional finite-element sim- ulations are performed to determine the capacitance matrix on a turn-to-turn basis. Then, a lumped parameter RLC

Pablo Gomez; Francisco de Leon; Iván A. Hernandez

2011-01-01

163

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

164

A survey of alternative once-through fast reactor core designs  

SciTech Connect

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

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

2012-07-01

165

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

E-print Network

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

Yarsky, Peter

2005-01-01

166

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

167

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

168

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

169

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

PubMed

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

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

2011-01-01

170

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

171

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

172

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 Central

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

173

Fracture strength of three-unit fixed partial denture cores (Y-TZP) with different connector dimension and design.  

PubMed

True crystalline ceramic materials presently used in restorative dentistry are Al2O3 (alumina) and yttrium-oxide stabilised tetragonal polycrystalline zirconium-dioxide (Y-TZP). To ensure optimal clinical performance, the dimensions of the Fixed Partial Denture (FPD) framework in general and of the connectors in particular, must be adequate. Considered recommendations for connector dimensions for Y-TZP FPDs vary from 2 to 4 mm in occluso-gingival height and 2 to 4 mm in bucco-lingual width. In order to reduce the fracture probability when designing all-ceramic FPDs, the shape of the connector is an important factor to consider. The radius of curvature at the gingival embrasure plays a significant role in the load-bearing capacity. FPDs with small gingival embrasure radii are subjected to high stress concentrations in the connector area during loading, compared to FPDs with large embrasure radii. The aim of this in-vitro study was to investigate how different radii of curvature in the embrasure of the connector area and different connector dimensions could affect the fracture resistance of 3-unit all-ceramic FPDs made of Y-TZP. Forty-eight FPDs in 6 groups of 8 FPDs with different connector design were produced in Procera Zirconia Bridge material. The FPD cores were subjected to heat treatment to simulate veneering. Following cementation, the FPDs were firstly thermocycled for 5,000 cycles, then preloaded for 10,000 cycles and finally loaded to fracture. All the FPDs fractured in the connector area. All the crack propagation which led to fracture started at the gingival embrasure of the connector. Within the limitations of this in-vitro study,the recommended minimum dimension of an anterior 3-unit all-ceramic FPD of Y-TZP is 3 mm in incisal-cervical direction and 2 mm in buccal-lingual direction. By increasing the radius of the gingival embrasure from 0.6 to 0.9 mm, the fracture strength for a Y-TZP FPD with connector dimension 3 x 3 mm increases by 20%. PMID:19994565

Bahat, Zdravko; Mahmood, Deyar J Hadi; Vult von Steyern, Per

2009-01-01

174

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

SciTech Connect

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 Cuiping; Liu Xingjun; Shi Rongpei; Shen Chen; Wang Yunzhi; Ohnuma, Ikuo; Kainuma, Ryosuke; Ishida, Kiyohito [Department of Materials Science and Engineering, Xiamen University, Xiamen 361005 (China); Department of Materials Science and Engineering, Ohio State University, 2041 College Road, Columbus, Ohio 43210 (United States); Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan)

2007-10-01

175

Novel design of a refractive index sensor based on a dual-core micro-structured optical fiber  

E-print Network

In the present work a new model of a refractive index (RI) sensor is exhibited. This is based on a dual core micro-structured optical fiber (MOF), where two holes are introduced at the core centers. In this way, the model enhances the interaction of the fiber modes propagated in the core region, providing the possibility of increasing the dimensions of the fiber sensor. Thus, the filling of the fiber holes with the fluid under study is facilitated, and generally the practical use of the system as a refractive index sensor is simplified. The influence of the core separation and the diameter of the central holes on the sensitivity of the sensor have been studied by a numerical simulation. The results are in agreement with the expected behavior as it is determined by the physics of the problem. Based on the same operating principle, it is verified that a dual-core conventional optical fiber with micro-fluidic channels at the center of the cores, can also operates as an RI sensor.

Tsigaridas, G; Persephonis, P

2014-01-01

176

Design of refractive index sensors based on the wavelength-selective resonant coupling phenomenon in dual-core photonic crystal fibers  

NASA Astrophysics Data System (ADS)

Design strategies for high-sensitivity refractive index sensors based on the principle of wavelength-selective resonant coupling in dual-core photonic crystal fibers are presented. Phase matching at a single wavelength can be achieved between an analyte-filled microstructured core and a small core with a down-doped rod or one small air hole in the center, thus enabling selectively directional resonant-coupling between the two cores. The transmission spectra of the output light presents a notch at the index-matched wavelength, yielding a resonant wavelength depending on the refractive index of the analyte. Numerical simulations demonstrate that both of the two proposed sensors can be used for highly sensitive detection of low-index analyte. In particular, the configuration realized by introducing the fiber with a small air hole in one core can be used to the detection of the analyte index around 1.33 and the sensitivity reach to 1.2×104 nm per refractive index unit (RIU). In addition, the detection limit is as low as 2.5×10-7 RIU at na=1.33.

Sun, Bing; Chen, Ming-Yang; Zhang, Yong-Kang; Yang, Ji-chang

2012-03-01

177

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

178

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

179

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

PubMed

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. PMID:24825997

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

2010-12-01

180

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. PMID:24825997

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

2010-01-01

181

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

182

Design of add-drop multiplexer based on multi-core optical fibers for mode-division multiplexing.  

PubMed

A multi-core fiber coupler is proposed to extract one of the modes in a few-mode optical fiber from a light beam, leaving the other modes undisturbed, and allowing a new signal to be retransmitted on that mode. Selective coupling of higher-order modes from a few-mode optical fiber can be realized by increasing the coupling length difference of the modes in the fiber using the multi-core configuration. Low cross-talk and wide bandwidth operation are realized owing to the fact that only one mode can be effectively coupled. PMID:24515151

Chen, Ming-Yang; Zhou, Jun

2014-01-27

183

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

184

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

185

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

Microsoft Academic Search

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

Shirley Vincent; Will Focht

2009-01-01

186

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

SciTech Connect

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

Parish, T.A.

1995-03-02

187

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

188

Mapping the Active Site in Vasoactive Intestinal Peptide to a Core of Four Amino Acids: Neuroprotective Drug Design  

Microsoft Academic Search

The understanding of the molecular mechanisms leading to peptide action entails the identification of a core active site. The major 28-aa neuropeptide, vasoactive intestinal peptide (VIP), provides neuroprotection. A lipophilic derivative with a stearyl moiety at the N-terminal and norleucine residue replacing the Met-17 was 100-fold more potent than VIP in promoting neuronal survival, acting at femtomolar-picomolar concentration. To identify

I. Gozes; O. Perl; E. Giladi; A. Davidson; O. Ashur-Fabian; S. Rubinraut; M. Fridkin

1999-01-01

189

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

190

Designing analysis of the polarization beam splitter in two communication bands based on a gold-filled dual-core photonic crystal fiber  

NASA Astrophysics Data System (ADS)

We design a novel kind of polarization beam splitter based on a gold-filled dual-core photonic crystal fiber (DC-PCF). Owing to filling with two gold wires in this DC-PCF, its coupling characteristics can be changed greatly by the second-order surface plasmon polariton (SPP) and the resonant coupling between the surface plasmon modes and the fiber-core guided modes can enhance the directional power transfer in the two fiber-cores. Numerical results by using the finite element method show the extinction ratio at the wavethlengths of 1.327 ?m and 1.55 ?m can reach -58 dB and -60 dB and the bandwidths as the extinction ratio better than -12 dB are about 54 nm and 47 nm, respectively. Compared with the gold-unfilled DC-PCF, a 1.746-mm-long gold-filled DC-PCF is better applied to the polarization beam splitter in the two communication bands of ? = 1.327 ?m and 1.55 ?m.

Fan, Zhen-Kai; Li, Shu-Guang; Fan, Yu-Qiu; Zhang, Wan; An, Guo-Wen; Bao, Ya-Jie

2014-09-01

191

Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64  

PubMed Central

Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its noninvasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective “CORE-64” trial (“Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors”). This multi-centre trialwas unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows. PMID:18998142

Vavere, Andrea L.; Rochitte, Carlos E.; Niinuma, Hiroyuki; Arbab-Zadeh, Armin; Paul, Narinder; Hoe, John; de Roos, Albert; Yoshioka, Kunihiro; Lemos, Pedro A.; Bush, David E.; Lardo, Albert C.; Texter, John; Brinker, Jeffery; Cox, Christopher; Clouse, Melvin E.; Lima, Joao A. C.

2012-01-01

192

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

193

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

E-print Network

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

Ellis, Tyler Shawn

2009-01-01

194

The fast-spectrum transmutation experimental facility FASTEF: Main design achievements (Part 1: Core and primary system) within the FP7-CDT collaborative project of the European Commission  

SciTech Connect

MYRRHA (Multi-purpose hybrid Research Reactor for High-tech Applications) is the flexible experimental accelerator-driven system (ADS) in development at SCK CEN in replacement of its material testing reactor BR2. SCK CEN in association with 17 European partners from industry, research centres and academia, responded to the FP7 (Seventh Framework Programme) call from the European Commission to establish a Central Design Team (CDT) for the design of a Fast Spectrum Transmutation Experimental Facility (FASTEF) able to demonstrate efficient transmutation and associated technology through a system working in subcritical and/or critical mode. The project has started on April 01, 2009 for a period of three years. In this paper, we present the latest configuration of the reactor core and primary system. The FASTEF facility has evolved quite a lot since the intermediate reporting done at the ICAPP'10 and ICAPP'11 conferences 1 2. If it remains a small-scale facility, the core power amounts now up to 100 MWth in critical mode. In a companion paper 3, we present the concept of the reactor building and the plant layout. (authors)

De Bruyn, D.; Fernandez, R. [Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400 Mol (Belgium); Mansani, L. [ANSALDO, Corso Perrone 25, 16152 Genova (Italy); Woaye-Hune, A. [AREVA-NP, rue Juliette Recamier 10, 69456 Lyon Cedex 06 (France); Sarotto, M. [ENEA, Via Martiri di Monte Sole 4, 40129 Bologna (Italy); Bubelis, E. [KIT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2012-07-01

195

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

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

196

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

197

Case Studies of Leading Edge Small Urban High Schools. Core Academic Strategic Designs: 2. Noble Street Charter High 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

198

Fusion Engineering and Design 41 (1998) 371376 The ARIES-RS power core--recent development in Li/V  

E-print Network

McDonnell Douglas Aerospace, City, USA Abstract The ARIES-RS fusion power plant design study is based tritium breeding, excellent high heat flux removal capability, long structural life time, low activation the performance of a fu- sion power plant. Proper selection of the materials have the following effects: 1

California at San Diego, University of

199

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

200

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

201

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

202

CANADIAN RISK MANAGEMENT PROGRAM (CRM) The CRM designation is awarded to students who have successfully completed the three core courses in Risk  

E-print Network

successfully completed the three core courses in Risk Management. These core courses also comprise the Risk Management major for the Fellow-Chartered Insurance Professional (FCIP/FIIC) RISK MANAGEMENT COURSES: · Risk successfully complete the three core courses in Risk Management, which also comprise the risk management major

Martin, Jeff

203

DUBLIN CORE  

EPA Science Inventory

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

204

Swinburne University of Technology Faculty of Design  

E-print Network

Complete Yet to be completed TP Year Core HDC004 Digital Design Core HDCOM124/ DCO10002 Design Studio: Digital Nil Nil Core HDCOM111 Introduction to Communication Design Core HDCOM113/ DCO10007 Design Studio Nil Nil Core HDC003 Design Studio Core HDCOM115/ DCO10001 Design Studio: Concepts & Narratives Nil Nil

Liley, David

205

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

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

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

206

MHTGR core temperature measurement trade study  

SciTech Connect

The objective of this task was to assess the need for core non-nuclear instrumentation. The focus of this study was the evaluation of core investment risk events. Three categories of events were considered: (1) unanticipated primary loop flow leakages and core bypass flows, (2) core coolant channel flow blockages and (3) off-design core power distributions. The measurements that were considered include column average coolant exit temperatures, core average coolant exit temperature, core pressure drop and core flow rate. The findings are summarized. 3 refs., 7 figs.

Kapernick, R.; Howard, W.

1989-09-29

207

Wire core reactor for NTP  

NASA Technical Reports Server (NTRS)

The development of the wire core system for Nuclear Thermal Propulsion (NTP) that took place from 1963 to 1965 is discussed. A wire core consists of a fuel wire with spacer wires. It's an annular flow core having a central control rod. There are actually four of these, with beryllium solid reflectors on both ends and all the way around. Much of the information on the concept is given in viewgraph form. Viewgraphs are presented on design details of the wire core, the engine design, engine weight vs. thrust, a technique used to fabricate the wire fuel element, and axial temperature distribution.

Harty, R. B.

1991-01-01

208

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

PubMed Central

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

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

2001-01-01

209

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

210

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

211

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

212

Core fluctuations test. Revision 1  

SciTech Connect

Fluctuations were first encountered in the Fort St. Vrain reactor early in cycle 1 operation, during the initial rise from 40% to 70% power. Subsequent in-core tests and operation throughout cycles 1 and 2 demonstrated that fluctuations were repeatable, occurring at core pressure drops of between 2.5 psi and 4.0 psi, and that in each instance their characteristics were very similar. Subsequently, tests and analysis were done to understand the core fluctuation phenomenon. These efforts also lead to a design fix which stopped these fluctuations in the FSV reactor core. This fix required that keys be used in addition to the keys in the core support floor which already existed. This report outlines a test plan to validate that core fluctuations will not occur in the MHTGR core. 2 refs., 12 figs., 3 tabs.

Betts, W.S.

1987-06-01

213

Cellular Truss Core Sandwich Structures  

Microsoft Academic Search

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

David J. Sypeck

2005-01-01

214

Core Challenge  

NSDL National Science Digital Library

This learning community provides a forum for teachers, parents, and students to share ideas about teaching and learning. The concept of this forum is centered around the Common Core Standards to aide in moving mathematics education forward through shared knowledge. The website provides opportunities for community members to contribute, review, and learn through "Educational Objects".

2012-01-01

215

Core restraint contributions to radial expansion reactivity  

SciTech Connect

Bowing of core assemblies caused by thermal gradients, swelling gradients, and irradiation creep can cause significant changes in reactivity of an LMFBR during startup, overpower and loss-of-flow without scram transients. This paper summarizes calculations of bowing reactivity effects for both a small homogeneous and a small heterogeneous core design. It includes two core restraint concepts for each core design and concentrates on reactivity changes in the critical power-to-flow range of 1.0 to 2.0.

Moran, T.J.

1986-01-01

216

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

217

Core-to-core uniformity improvement in multi-core fiber Bragg gratings  

NASA Astrophysics Data System (ADS)

Multi-core fiber Bragg gratings (MCFBGs) will be a valuable tool not only in communications but also various astronomical, sensing and industry applications. In this paper we address some of the technical challenges of fabricating effective multi-core gratings by simulating improvements to the writing method. These methods allow a system designed for inscribing single-core fibers to cope with MCFBG fabrication with only minor, passive changes to the writing process. Using a capillary tube that was polished on one side, the field entering the fiber was flattened which improved the coverage and uniformity of all cores.

Lindley, Emma; Min, Seong-Sik; Leon-Saval, Sergio; Cvetojevic, Nick; Jovanovic, Nemanja; Bland-Hawthorn, Joss; Lawrence, Jon; Gris-Sanchez, Itandehui; Birks, Tim; Haynes, Roger; Haynes, Dionne

2014-07-01

218

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

219

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

220

Design and testing of full-scale 10 kV prototype of inductive fault current limiter with a common core and trifilar windings  

Microsoft Academic Search

Fault Current Limiters (FCLs) are expected to play an important role in protection of future power systems against excessive fault currents. Inductive saturated-core FCLs have supreme performance in comparison to other FCLs types: inherent reaction on a fault, inherent post-fault recovery and unrestricted duration of a fault limiting period. However, they are not commercialized due to too large amount of

D. Cvoric; S. W. H. de Haan; J. A. Ferreira; M. van Riet; J. Bozelie

2010-01-01

221

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

222

Illusionist: Transforming Lightweight Cores into Aggressive Cores on Demand  

E-print Network

of Illinois amina@illinois.edu Shuguang Feng Northrop Grumman Corp. shoe@umich.edu Shantanu Gupta Intel Corp integration have led microprocessor vendors to design chip multiprocessors (CMPs) with relatively simple (lightweight) cores. While these designs provide high throughput, single- thread performance has stagnated

Torrellas, Josep

223

A scaling study of the natural circulation flow of the ex-vessel core catcher cooling system of EU-APR1400 for designing a scale-down test facility for design verification  

SciTech Connect

In this paper a scaling study on the steady state natural circulation flow along the flow path of the ex vessel core catcher cooling system of EU-APR1400 is described, and the scaling criteria for reproducing the same steady state thermalhydraulic characteristics of the natural circulation flow as a prototype core catcher cooling system in the scale-down test facility are derived in terms of the down-comer pipe diameter and orifice resistance. (authors)

Rhee, B. W.; Ha, K. S.; Park, R. J.; Song, J. H. [Korea Atomic Energy Research Inst., 1045 Daedukdaero, Yusong-Gu, Daejon (Korea, Republic of); Revankar, S. T. [Div. of Advanced Nuclear Engineering, POSTECH, Pohang (Korea, Republic of)

2012-07-01

224

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

225

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

226

An Innovative Three-Dimensional Heterogeneous Coarse-Mesh Transport Method for Advanced and Generation IV Reactor Core Analysis and Design  

SciTech Connect

This project has resulted in a highly efficient method that has been shown to provide accurate solutions to a variety of 2D and 3D reactor problems. The goal of this project was to develop (1) an accurate and efficient three-dimensional whole-core neutronics method with the following features: based sollely on transport theory, does not require the use of cross-section homogenization, contains a highly accurate and self-consistent global flux reconstruction procedure, and is applicable to large, heterogeneous reactor models, and to (2) create new numerical benchmark problems for code cross-comparison.

Farzad Rahnema

2009-11-12

227

A study on the effect of various design parameters on the natural circulation flow rate of the ex-vessel core catcher cooling system of EU-APR1400  

SciTech Connect

In this paper, a study on the effect of various design parameters such as the channel gap width, heat flux distribution, down-comer pipe size and two-phase flow slip ratio on the natural circulation flow rate is performed based on a physical model for a natural circulation flow along the flow path of the ex-vessel core catcher cooling system of an EU-APR1400, and these effects on the natural circulation flow rate are analyzed and compared with the minimum flow rate required for the safe operation of the system. (authors)

Rhee, B. W.; Ha, K. S.; Park, R. J.; Song, J. H. [Korea Atomic Energy Research Inst., 1045 Daedukdaero, Yusong-Gu, Daejon (Korea, Republic of)

2012-07-01

228

Structural and optical properties of Zn0.9Mn0.1O/ZnO core-shell nanowires designed by pulsed laser deposition  

NASA Astrophysics Data System (ADS)

Core-shell ZnO/ZnMnO nanowires on a-Al2O3 and GaN (buffer layer)/Si (111) substrates were fabricated by pulsed laser deposition using a Au catalyst. Two ZnO targets with a Mn content of 10% were sintered at 1150 and 550 °C in order to achieve the domination in them of paramagnetic MnO2 and ferromagnetic Mn2O3 phases, respectively. Cluster mechanism of laser ablation as a source of possible incorporation of secondary phases to the wire shell is discussed. Raman spectroscopy under excitation by an Ar+ laser revealed a broad peak related to the Mn-induced disorder and a redshift in the A1-LO phonon. Resonant Raman measurements revealed an increase in the multiphonon scattering caused by disorder in ZnO upon doping by Mn. Besides the UV emission, a vibronic green emission band assisted by a ˜71 meV LO phonon is also observed in the photoluminescence spectra. Core-shell structures with smooth shells show a high exciton to green band intensity ratio (˜10) even at room temperature.

Kaydashev, V. E.; Kaidashev, E. M.; Peres, M.; Monteiro, T.; Correia, M. R.; Sobolev, N. A.; Alves, L. C.; Franco, N.; Alves, E.

2009-11-01

229

Residential Utility Core Wall System - ResCore  

SciTech Connect

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

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

1999-06-01

230

Designing of a polarization beam splitter for the wavelength of 1310 nm on dual-core photonic crystal fiber with high birefringence and double-zero dispersion  

NASA Astrophysics Data System (ADS)

We have proposed a novel kind of photonic crystal fiber which contains two asymmetric cores. The birefringence and the dispersion are numerically analyzed based on finite element method when the size of the air holes and the pitch of two adjacent air holes are changed. It is shown that the proposed photonic crystal fiber has high birefringence up to the order of 10−2 and double-zero dispersion points are at the wavelengths of 1310 nm and 800 nm, simultaneously. At the same time, the normalized power and the extinction ratios of the proposed photonic crystal fiber have been simulated. It is demonstrated that, at the wavelength of 1310 nm, the x-polarized mode and the y-polarized mode are separated when the propagation distance is 2.481 mm.

Bao, Ya-Jie; Li, Shu-Guang; Zhang, Wan; An, Guo-Wen; Fan, Zhen-Kai

2014-10-01

231

Bowing of core assemblies in advanced liquid metal fast reactors  

Microsoft Academic Search

Two alternative core restraint concepts are considered for a conceptual design of a 900 MWth liquid metal fast reactor core with a heterogeneous layout. The two concepts, known as limited free bowing and free flowering, are evaluated based on core bowing criteria that emphasize the echancement of inherent reactor safety. The core reactivity change during a postulated loss of flow

S. A. Kamal; Y. Orechwa

1986-01-01

232

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. PMID:22146496

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

233

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

234

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

PubMed

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

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

2013-11-01

235

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

236

RIKEN Quantitative Biology Center Cell Dynamics Research Core  

E-print Network

Regulation Laboratory for Biomolecular Structure and Dynamics Computational Biology Research Core LaboratoryRIKEN Quantitative Biology Center Cell Dynamics Research Core Laboratory for Cell Dynamics for Computational Molecular Design Drug Discovery Molecular Simulation Platform Unit Laboratory for Biomolecular

Fukai, Tomoki

237

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

238

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

239

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

240

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

241

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

242

Core performance tests for the JOYO MK-III upgrade  

Microsoft Academic Search

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

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

2007-01-01

243

"CanCore": In Canada and around the World  

ERIC Educational Resources Information Center

In this article, the author discusses "CanCore," a learning resource metadata initiative funded by Industry Canada and supported by Athabasca University, Alberta, and TeleUniversite du Quebec, and describes the increasing range of international uses of the "CanCore" metadata for the indexing of learning objects. "CanCore" is designed to facilitate…

Friesen, Norm

2005-01-01

244

An Alternating Current Amplitude Sensor Utilizing Saturating Magnetic Cores  

Microsoft Academic Search

Toroidal magnetic cores are used for noncontacting alternating current-sensing in applications such as circuit breakers and ground fault interrupters. In such applications, it is often desirable to maximize the voltage induced in the sense coil on the core. In order to maximize this voltage with respect to the sensed current, core design parameters are developed for 60- and 400-Hz applications.

THEODORE BERNSTEIN

1970-01-01

245

23. CORE WORKER OPERATING A COREBLOWER THAT PNEUMATICALLY FILLED CORE ...  

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

23. CORE WORKER OPERATING A CORE-BLOWER THAT PNEUMATICALLY FILLED CORE BOXES WITH RESIGN IMPREGNATED SAND AND CREATED A CORE THAT THEN REQUIRED BAKING, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

246

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

247

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

248

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

249

Turbo decoder core design for system development  

Microsoft Academic Search

Due to their near Shannon-capacity performance, turbo codes have received a considerable amount of attention since their introduction. They are particularly attractive for cellular communication systems and have been included in the specifications for both the WCDMA(UMTS) and cdma2000 third-generation cellular standards. The log-MAP decoding algorithm and some technologies used to reduce the complexity have discussed in the past days.

Xiaoyi Chen; Qingdong Yao; Peng Liu

2003-01-01

250

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

251

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. PMID:24066701

2013-01-01

252

The effects of core geometry on core power for passively safe HTGRs  

SciTech Connect

Decay heat removal under accident conditions is one of the major concerns of nuclear reactor safety. By imposing a limit on the core power density, reactor designers can ensure that the energy generated after shutdown would not pose any problem even when the active cooling agent is lost. On the other hand, it is usually desirable to have a high power density for the competitiveness of the reactor design. Therefore, the design approach must make maximum use of passive means of heat transfer for obtaining the highest achievable core power density without sacrificing passive safety. The strong temperature dependence of radiative heat transfer combined with the high-temperature operability of coated-particle-fueled gas-cooled reactors can provide a valuable opportunity in this regard. To enhance radiative heat transfer within the core, an optimization of the design parameters, such as core geometry, fuel element configuration, and a proper choice of the materials, would be necessary in addition to neutronics considerations.

Kubali, V.C.; Lidsky, L.M. (Massachusetts Institute of Technology, Cambridge (United States))

1993-01-01

253

KSI's Cross Insulated Core Transformer Technology  

NASA Astrophysics Data System (ADS)

Cross Insulated Core Transformer (CCT) technology improves on Insulated Core Transformer (ICT) implementations. ICT systems are widely used in very high voltage, high power, power supply systems. In an ICT transformer ferrite core sections are insulated from their neighboring ferrite cores. Flux leakage is present at each of these insulated gaps. The flux loss is raised to the power of stages in the ICT design causing output voltage efficiency to taper off with increasing stages. KSI's CCT technology utilizes a patented technique to compensate the flux loss at each stage of an ICT system. Design equations to calculate the flux compensation capacitor value are presented. CCT provides corona free operation of the HV stack. KSI's CCT based High Voltage power supply systems offer high efficiency operation, high frequency switching, low stored energy and smaller size over comparable ICT systems.

Uhmeyer, Uwe

2009-08-01

254

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

255

Dublin Core Metadata Initiative  

NSDL National Science Digital Library

Dublin Core metadata has been implemented in several ways, including as HTML metatags and as database elements, as it is used in the Scout Archives (discussed in the June 20, 1997 issue of the Scout Report). The DC elements are title, author, subject, description, publisher, other contributor, date, resource type, format, resource identifier, source, language, relation, coverage, and rights management. Information about the Dublin Core Workshop Series, DC semantics and syntax, working papers, and projects that have implemented Dublin Core metadata can be found at the Dublin Core Metadata homepage.

1995-01-01

256

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

257

Core Physics and Kinetics Calculations for the Fissioning Plasma Core Reactor  

NASA Technical Reports Server (NTRS)

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

Butler, C.; Albright, D.

2007-01-01

258

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

259

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

260

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

261

Core Concepts of Kinesiology.  

ERIC Educational Resources Information Center

Core concepts of kinesiology are the basis of communication about movement that facilitate progression of skill levels. The article defines and exemplifies each of 10 core concepts: range of motion, speed of motion, number of segments, nature of segments, balance, coordination, compactness, extension at release/contact, path of projection, and…

Hudson, Jackie L.

1995-01-01

262

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

263

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

264

Ice Core Investigations  

ERIC Educational Resources Information Center

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

Krim, Jessica; Brody, Michael

2008-01-01

265

Thermal hydraulics analysis of the MIT research reactor in support of a low enrichment uranium (LEU) core conversion  

E-print Network

The MIT research reactor (MITR) is converting from the existing high enrichment uranium (HEU) core to a low enrichment uranium (LEU) core using a high-density monolithic UMo fuel. The design of an optimum LEU core for the ...

Ko, Yu-Chih, Ph. D. Massachusetts Institute of Technology

2008-01-01

266

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.

267

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

268

Core sample depth relationships - Apollo 14 and 15.  

NASA Technical Reports Server (NTRS)

The depth relationships for the Apollo 14 and 15 core tubes and the Apollo 15 drill core are presented, as determined from laboratory simulation studies. Sample at a depth of 40 cm in the Apollo 14 double core tube (virtually the same as the Apollo 12 tubes) represents material from a depth of approximately 58 cm in the lunar surface. The new design of the Apollo 15 core tube results in much less sample disturbance and the depth relationship is practically one-to-one, with sample recovery approaching 100%. The depth relationship for the drill core is also probably close to one-to-one, and its recovery ratio was also 100%.

Carrier, W. D., III; Johnson, S. W.; Carrasco, L. H.; Schmidt, R.

1972-01-01

269

Biopolymers & Proteomics Core Facility  

E-print Network

Biopolymers & Proteomics Core Facility 76-185 x4-2609 Proteomics Sample Form (one form per sample information, previously acquired mass spectral data, etc.) Proteomics Division Use Only DATES RECEIVED

Sabatini, David M.

270

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.

271

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.

272

Transient bowing of core assemblies in advanced liquid metal fast reactors  

Microsoft Academic Search

Two alternative core restraint concepts are considered for a conceptual design of a 900 MWth liquid metal fast reactor core with a heterogeneous layout. The two concepts, known as limited free bowing and free flowering, are evaluated based on core bowing criteria that emphasize the enhancement of inherent reactor safety. The core reactivity change during a postulated loss of flow

S. A. Kamal; Y. Orechwa

1986-01-01

273

Central core disease  

Microsoft Academic Search

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

Heinz Jungbluth

2007-01-01

274

Daylighting Design  

NSDL National Science Digital Library

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

Integrated Teaching And Learning Program

275

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

276

Cannulated screw with solid core insert: stronger than cannulated screws.  

PubMed

We conducted a study to determine if there is a significant difference in ultimate load, yield strength, and fatigue strength between solid core screws and cannulated screws and if a solid core insert placed inside a cannulated screw would have biomechanical effects similar to those of a solid core screw. Five screw designs were tested: Synthes 4.5-mm solid core and 4.5-mm cannulated and our prototype 4.0-mm solid core, 4.0-mm cannulated, and 4.0-mm cannulated with solid core insert. Biomechanical testing with 3-point bending was used to determine ultimate load, yield strength, and cycles to failure for 6 screws of each design. Ultimate load, yield strength, and cycles to failure were significantly (P < .05) lower in the Synthes 4.5-mm cannulated screws than in the Synthes solid core screws and significantly lower in the prototype cannulated screws than in the prototype solid core screws (P < .05) and prototype cannulated screws with solid core inserts (P < .05). There was no significant difference (P > .05) in ultimate load, yield strength, or cycles to failure between the prototype cannulated screws with solid core inserts and the prototype solid core screws. PMID:25251531

Dundon, John M; Gould, Gregory C; Herbenick, Michael A; Hamilton, J Adam

2014-09-01

277

Efficiency of static core turn-off in a system-on-a-chip with variation  

DOEpatents

A processor-implemented method for improving efficiency of a static core turn-off in a multi-core processor with variation, the method comprising: conducting via a simulation a turn-off analysis of the multi-core processor at the multi-core processor's design stage, wherein the turn-off analysis of the multi-core processor at the multi-core processor's design stage includes a first output corresponding to a first multi-core processor core to turn off; conducting a turn-off analysis of the multi-core processor at the multi-core processor's testing stage, wherein the turn-off analysis of the multi-core processor at the multi-core processor's testing stage includes a second output corresponding to a second multi-core processor core to turn off; comparing the first output and the second output to determine if the first output is referring to the same core to turn off as the second output; outputting a third output corresponding to the first multi-core processor core if the first output and the second output are both referring to the same core to turn off.

Cher, Chen-Yong; Coteus, Paul W; Gara, Alan; Kursun, Eren; Paulsen, David P; Schuelke, Brian A; Sheets, II, John E; Tian, Shurong

2013-10-29

278

Ice core drilling at Vostok  

NSF Publications Database

... Subject: Initial Environmental Evaluation (Deep Ice Core Drilling at Vostok Station, Antarctica ... for the National Science Foundation's Deep Ice Core Drilling project at Vostok Station, prepare an ...

279

Fast Flux Test Facility core system  

SciTech Connect

A review of Liquid Metal Reactor (LMR) core system accomplishments provides an excellent road map through the maze of issues that faced reactor designers 10 years ago. At that time relatively large uncertainties were associated with fuel pin and fuel assembly performance, irradiation of structural materials, and performance of absorber assemblies. The extensive core systems irradiation program at the US Department of Energy's Fast Flux Test Facility (FFTF) has addressed each of these principal issues. As a result of the progress made, the attention of long-range LMR planners and designers can shift away from improving core systems and focus on reducing capital costs to ensure the LMR can compete economically in the 21st century with other nuclear reactor concepts. 3 refs., 6 figs., 1 tab.

Ethridge, J.L. (Pacific Northwest Lab., Richland, WA (USA)); Baker, R.B.; Leggett, R.D.; Pitner, A.L.; Waltar, A.E. (Westinghouse Hanford Co., Richland, WA (USA))

1990-11-01

280

Nested antiresonant nodeless hollow core fiber.  

PubMed

We propose a novel hollow core fiber design based on nested and non-touching antiresonant tube elements arranged around a central core. We demonstrate through numerical simulations that such a design can achieve considerably lower loss than other state-of-the-art hollow fibers. By adding additional pairs of coherently reflecting surfaces without introducing nodes, the Hollow Core Nested Antiresonant Nodeless Fiber (HC-NANF) can achieve values of confinement loss similar or lower than that of its already low surface scattering loss, while maintaining multiple and octave-wide antiresonant windows of operation. As a result, the HC-NANF can in principle reach a total value of loss - including leakage, surface scattering and bend contributions - that is lower than that of conventional solid fibers. Besides, through resonant out-coupling of high order modes they can be made to behave as effectively single mode fibers. PMID:25321960

Poletti, Francesco

2014-10-01

281

Interfacing Cores with On-chip Packet-Switched Networks  

Microsoft Academic Search

With the emergence of the packet-switched networks as a possible system-on-chip (SoC) communication paradigm, the design of network-on-chips (NoC) has provided a challenge to the designers. Meeting latency requirements of communication among various cores is one of the crucial objectives for system designers. The core interface to the networking logic and the communication network are the key contributors to latency.

Praveen Bhojwani; Rabi N. Mahapatra

2003-01-01

282

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

283

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

284

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

285

Core Curriculum. A Workplace Specific Curriculum.  

ERIC Educational Resources Information Center

This core curriculum is designed for use in helping employees participating in a workplace-specific basic skills program develop basic team-building skills while simultaneously developing basic reading, writing, and mathematics skills. Although many of the instructional materials and sample forms included are applicable to employees in most…

Nickles, Ann; And Others

286

Matrix Acidizing Parallel Core Flooding Apparatus  

E-print Network

, the apparatus is readily portable. Electrical components were enclosed and wiring was shielded. The heating system was designed to maintain temperature. The pressure transducers were appropriately calibrated. A LabVIEW VI file was written with proper function... .................................................................................. 92 Figure 74: Save File Location ...................................................................................... 94 Figure 75: Core Data Inputs and Temperature Observation .......................................... 94 Figure 76: Temperature...

Ghosh, Vivek

2013-07-23

287

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.

288

Ice Core Exercise  

NSDL National Science Digital Library

Students access the ice core data archived at Lamont-Doherty Geological Observatory. They select a core (Greenland, Antarctica, Quelcaya), pose a working hypothesis regarding the data, import the data in an Excel-readable format, and examine the data to determine correlations between variables and cause/effect as recorded in leads and lags. They generate a written and graphical analysis of the data and, in the next lab period, discuss the similarities and differences among their group outputs in terms of demonstrated correlations, assumptions required, effects of latitude, and any other item that arises.

Locke, William

289

Experiment and calculation on seismic behavior of RC composite core walls with concealed steel truss  

Microsoft Academic Search

To improve the seismic performance of reinforced concrete core walls, reinforced concrete composite core walls with concealed\\u000a steel truss were proposed and systemically investigated. Two 1\\/6 scale core wall specimens, including a normal reinforced\\u000a concrete core wall and a reinforced concrete composite core wall with concealed steel truss, were designed. The experimental\\u000a study on seismic performance under cyclic loading was

Wanlin Cao; Weihua Chang; Changjun Zhao; Jianwei Zhang

2009-01-01

290

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

291

Measurement of flux distribution in toroidal and multiaperture cores  

Microsoft Academic Search

Recently, magnetic devices utilizing a partial switching have been used in many fields. From a point of core design, a flux distribution must be known. It is possible to calculate them under some assumptions, but it is difficult to measure them experimentally. This paper describes a technique of determining a flux distribution in toroidal and multiaperture ferrite cores. The patterns

Y. Ohbuchi; T. Urabe; Y. Sakurai

1971-01-01

292

BREAKING THE MEMORY WALL FOR HIGHLY MULTI-THREADED CORES  

E-print Network

BREAKING THE MEMORY WALL FOR HIGHLY MULTI-THREADED CORES THIS DISSERTATION IS SUBMITTED IN PARTIAL mining are commonly computation- and data- intensive [1], and they usually exhibit abundant parallelism. These applications motivate the design of throughput- oriented many- and multi-core architectures that employ many

Skadron, Kevin

293

Allied Health Core Curriculum: Its Time Has Come  

ERIC Educational Resources Information Center

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

McPherson, M. LaCheeta

2004-01-01

294

Acoustics in mechanical engineering undergraduate core courses: Challenges and opportunities  

Microsoft Academic Search

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

M. G. Prasad

2005-01-01

295

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.

296

Core Security Requirements Artefacts  

Microsoft Academic Search

Although security requirements engineering has recently attracted increasing attention, it has lacked a context in which to operate. A number of papers have described how security requirements may be violated, but apart from a few hints in the general literature, none have described satisfactorily what security requirements are. This paper proposes a framework of core security requirements artefacts, which unifies

Jonathan D Moffett Charles; B Haley; Bashar Nuseibeh

2004-01-01

297

Authentic to the Core  

ERIC Educational Resources Information Center

When educators think about what makes learning relevant to students, often they narrow their thinking to electives or career technical education. While these provide powerful opportunities for students to make relevant connections to their learning, they can also create authentic experiences in the core curriculum. In the San Juan Unified School…

Kukral, Nicole; Spector, Stacy

2012-01-01

298

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

299

The Uncommon Core  

ERIC Educational Resources Information Center

This author contends that the United States neglects creativity in its education system. To see this, he states, one may look at the Common Core State Standards. If one searches the English Language Arts and Literacy standards for the words "creative," "innovative," and "original"--and any associated terms, one will find scant mention of the words…

Ohler, Jason

2013-01-01

300

QEP Core Committee  

Microsoft Academic Search

Charge The QEP Core Committee creates, writes, and coordinates the implementation of the Quality Enhancement Plan. It is the Committee's responsibility to ensure that the plan is technically responsive to requirements outlined in the Quality Enhancement Plan section of the DRAFT Handbook for Institutional Analysis by the Southern Association of Colleges and Schools, Commission on Colleges, 2003; to keep the

Suzanne Morales; John Frith; Terri Jackson

301

Electromagnetic pump stator core  

SciTech Connect

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

302

The Earth's Core.  

ERIC Educational Resources Information Center

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

Jeanloz, Raymond

1983-01-01

303

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

304

Renewing the Core Curriculum  

ERIC Educational Resources Information Center

The core curriculum accompanied the development of the academic discipline with multiple names such as Kinesiology, Exercise and Sport Science, and Health and Human Performance. It provides commonalties for undergraduate majors. It is timely to renew this curriculum. Renewal involves strategic reappraisals. It may stimulate change or reaffirm the…

Lawson, Hal A.

2007-01-01

305

Navagating the Common Core  

ERIC Educational Resources Information Center

This article presents a debate over the Common Core State Standards Initiative as it has rocketed to the forefront of education policy discussions around the country. The author contends that there is value in having clear cross state standards that will clarify the new online and blended learning that the growing use of technology has provided…

McShane, Michael Q.

2014-01-01

306

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

307

Core competence (knowledge) (skill)  

E-print Network

Core competence 8 5~8 2 3 4 5 6 7 8 PPS003 Ver. 1.1 2011/03/07 #12; 2 (knowledge) (skill) (attitude) Set of skill, knowledge or attitude which should be learned or acquired by each, 2000) (knowledge) (skill) (attitude) Set of skill, knowledge or attitude which should be learned

Wu, Yih-Min

308

The ADNI PET Core  

PubMed Central

Background This is a progress report of the Alzheimer's Disease Neuroimaging Initiative (ADNI) PET Core. Methods The Core has supervised the acquisition, quality control, and analysis of longitudinal [18F]fluorodeoxyglucose PET (FDG-PET) data in approximately half of the ADNI cohort. In an “add on” study, approximately 100 subjects also underwent scanning with [11C]PIB-PET for amyloid imaging. The Core developed quality control procedures and standardized image acquisition by developing an imaging protocol that has been widely adopted in academic and pharmaceutical industry studies. Data processing provides users with scans that have identical orientation and resolution characteristics despite acquisition on multiple scanner models. The Core labs have used a number of different approaches to characterize differences between subject groups (AD, MCI, controls), to examine longitudinal change over time in glucose metabolism and amyloid deposition, and to assess the use of FDG-PET as a potential outcome measure in clinical trials. Results ADNI data indicate that FDG-PET increases statistical power over traditional cognitive measures, might aid subject selection, and could substantially reduce the sample size in a clinical trial. PIB-PET data showed expected group differences, and identified subjects with significant annual increases in amyloid load across the subject groups. The next activities of the PET core in ADNI will entail developing standardized protocols for amyloid imaging using the [18F]-labeled amyloid imaging agent AV45, which can be delivered to virtually all ADNI sites. Conclusions ADNI has demonstrated the feasibility and utility of multicenter PET studies and is helping to clarify the role of biomarkers in the study of aging and dementia. PMID:20451870

Jagust, William J.; Bandy, Dan; Chen, Kewei; Foster, Norman L.; Landau, Susan M.; Mathis, Chester A.; Price, Julie C.; Reiman, Eric M.; Skovronsky, Daniel; Koeppe, Robert A.

2010-01-01

309

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

310

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

311

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

312

Designing structural sandwich composites  

SciTech Connect

Composite sandwich structures have been used in aircraft for many years. Most are based on honeycomb cores with relatively high modulus composite skin materials. Today, with increasing use of composites in many other markets, designing structural sandwich composites has become very important. Most of these applications use relatively low modulus composite skins and a low density core other than honeycomb. The mechanics and the failure mode of these sandwich structures differ significantly from honeycomb core structures. Designers of structural sandwich composites must take into account not only the safety of a structural part, defined as strength design, but the functionality of the part as well. Doing so requires rigidity design, in which both strength and deflection requirements must be met. The process of optimizing dimensions is initially based on rigidity requirements. Once these are met, strength verification can be carried out. In addition to design strength and rigidity, the designer must also select structural core material which meets the temperature, pressure, and processing conditions of molding composite sandwich skins, a core material which results in good skin-to-core bonding, and one which provides good economics. ISORCA has been conducting research and development on a new concept of structural syntactic phenolic foam, called Alba-Core{trademark}. It excels in shear modulus, compression strength, temperature stability, skin resin absorption, skin bonding, smoke, flame, toxicity, and moisture absorption. It is moldable to any shape, can be made with domestic raw materials, and has very attractive economics.

Meteer, C.L. [ISORCA, Inc., Granville, OH (United States)

1996-11-01

313

Solid0Core Heat-Pipe Nuclear Batterly Type Reactor  

SciTech Connect

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

Ehud Greenspan

2008-09-30

314

PRISMATIC CORE COUPLED TRANSIENT BENCHMARK  

SciTech Connect

The Prismatic Modular Reactor (PMR) is one of the High Temperature Reactor (HTR) design concepts that have existed for some time. Several prismatic units have operated in the world (DRAGON, Fort St. Vrain, Peach Bottom) and one unit is still in operation (HTTR). The deterministic neutronics and thermal-fluids transient analysis tools and methods currently available for the design and analysis of PMRs have lagged behind the state of the art compared to LWR reactor technologies. This has motivated the development of more accurate and efficient tools for the design and safety evaluations of the PMR. In addition to the work invested in new methods, it is essential to develop appropriate benchmarks to verify and validate the new methods in computer codes. The purpose of this benchmark is to establish a well-defined problem, based on a common given set of data, to compare methods and tools in core simulation and thermal hydraulics analysis with a specific focus on transient events. The benchmark-working group is currently seeking OECD/NEA sponsorship. This benchmark is being pursued and is heavily based on the success of the PBMR-400 exercise.

J. Ortensi; M.A. Pope; G. Strydom; R.S. Sen; M.D. DeHart; H.D. Gougar; C. Ellis; A. Baxter; V. Seker; T.J. Downar; K. Vierow; K. Ivanov

2011-06-01

315

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

316

NEW SOIL VOC SAMPLERS: EN CORE AND ACCU CORE SAMPLING/STORAGE DEVICES FOR VOC ANALYSIS  

SciTech Connect

Soil sampling and storage practices for volatile organic analysis must be designed to minimize loss of volatile organic compounds (VOCs) from samples. The En Core{reg_sign} sampler is designed to collect and store soil samples in a manner that minimizes loss of contaminants due to volatilization and/or biodegradation. An ASTM International (ASTM) standard practice, D 6418, Standard Practice for Using the Disposable En Core Sampler for Sampling and Storing Soil for Volatile Organic Analysis, describes use of the En Core sampler to collect and store a soil sample of approximately 5 grams or 25 grams for volatile organic analysis and specifies sample storage in the En Core sampler at 4 {+-} 2 C for up to 48 hours; -7 to -21 C for up to 14 days; or 4 {+-} 2 C for up to 48 hours followed by storage at -7 to -21 C for up to five days. This report discusses activities performed during the past year to promote and continue acceptance of the En Core samplers based on their performance to store soil samples for VOC analysis. The En Core sampler is designed to collect soil samples for VOC analysis at the soil surface. To date, a sampling tool for collecting and storing subsurface soil samples for VOC analysis is not available. Development of a subsurface VOC sampling/storage device was initiated in 1999. This device, which is called the Accu Core{trademark} sampler, is designed so that a soil sample can be collected below the surface using a dual-tube penetrometer and transported to the laboratory for analysis in the same container. Laboratory testing of the current Accu Core design shows that the device holds low-level concentrations of VOCs in soil samples during 48-hour storage at 4 {+-} 2 C and that the device is ready for field evaluation to generate additional performance data. This report discusses a field validation exercise that was attempted in Pennsylvania in 2004 and activities being performed to plan and conduct a field validation study in 2006. A draft ASTM practice describing use of the Accu Core sampler is being prepared. An update on the status of the ASTM practice is given in this report.

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

2006-06-01

317

Long Valley Coring Project  

USGS Publications Warehouse

In December 1997, the California Energy Commission (CEC) agreed to provide funding for Phase III continued drilling of the Long Valley Exploratory Well (LVEW) near Mammoth Lakes, CA, from its present depth. The CEC contribution of $1 million completes a funding package of $2 million from a variety of sources, which will allow the well to be cored continuously to a depth of between 11,500 and 12,500 feet. The core recovered from Phase III will be crucial to understanding the origin and history of the hydrothermal systems responsible for the filling of fractures in the basement rock. The borehole may penetrate the metamorphic roof of the large magmatic complex that has fed the volcanism responsible for the caldera and subsequent activity.

Sass, John; Finger, John; McConnel, Vicki

1998-01-01

318

Coring Methane Hydrate by using Hybrid Pressure Coring System of D/V Chikyu  

NASA Astrophysics Data System (ADS)

Pressure coring is a technique to keep in-situ conditions in recovering sub-seafloor sediment samples, which are potentially rich in soluble or hydrated gas. In regular core sampling, gas fractions are easily lost through the changes in the pressure and temperature during core recovery, and it has significant impact on the chemical components of the sample. Rapid degassing may also cause critical damages of original structures. To study original characteristics of gaseous sub-seafloor sediment, a new Hybrid Pressure Coring System (Hybrid PCS) was developed for the D/V Chikyu operation by adapting some of the existing pressure sampling technologies. Hybrid PCS is composed of three main parts: top section for the wireline operation, middle section for the accumulator and pressure controlling system, and the bottom section for the autoclave chamber. The design concept is based on that of Pressure Core Sampler used in Ocean Drilling Program, and of Pressure Temperature Core Sampler (PTCS) and Non-cooled PTCS of Japan Oil, Gas and Metals National Corporation (JOGMEC). Several modifications were made including that on the ball valve, which operates to close the autoclave after coring. The core samples are 51 mm in diameter and up to 3.5 m in length. The system is combined with the Extented Shoe Coring System on the Chikyu and best suited for coring of semi-consolidated formation up to about 3400 m from the sea level. Sample autoclave is compatible with Pressure Core Analysis and Transfer System (PCATS) of Geotek Ltd for sub-sampling and analysis under in-situ pressure. The analysis in PCATS includes X-ray CT scan and core logging with P-wave velocity and gamma density. Depressurization provides accurate volume of gas and its sub-sampling. Hybrid PCS was first tested during the Chikyu Exp. 906 at a submarine mud-volcano in the Nankai Trough. A 0.9 m of hydrate rich material was recovered from the summit (water depth: 2000 m) and the intact hydrate structure was observed by X-ray CT scan. Hybrid PCS was also used in the following JOGMEC methane hydrate cruise, resulting in the good recovery of methane hydrate-bearing cores (approx. 69%).

Kubo, Y.; Mizuguchi, Y.; Inagaki, F.; Eguchi, N.; Yamamoto, K.

2013-12-01

319

Cross Cell Sandwich Core  

NASA Technical Reports Server (NTRS)

A sandwich core comprises two faceplates separated by a plurality of cells. The cells are comprised of walls positioned at oblique angles relative to a perpendicular axis extending through the faceplates. The walls preferably form open cells and are constructed from open cells and are constructed from rows of ribbons. The walls may be obliquely angled relative to more than one plane extending through the perpendicular axis.

Ford, Donald B. (Inventor)

2004-01-01

320

Banded electromagnetic stator core  

DOEpatents

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figs.

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

1996-06-11

321

Banded electromagnetic stator core  

DOEpatents

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

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

1994-04-05

322

Banded electromagnetic stator core  

DOEpatents

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

Fanning, Alan W. (San Jose, CA); Gonzales, Aaron A. (San Jose, CA); Patel, Mahadeo R. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

1994-01-01

323

Banded electromagnetic stator core  

DOEpatents

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

Fanning, Alan W. (San Jose, CA); Gonzales, Aaron A. (San Jose, CA); Patel, Mahadeo R. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

1996-01-01

324

Electromagnetic pump stator core  

SciTech Connect

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. 21 figures.

Fanning, A.W.; Olich, E.E.; Dahl, L.R.

1995-01-17

325

Variable depth core sampler  

DOEpatents

A variable depth core sampler apparatus is described comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member. 7 figs.

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

1996-02-20

326

Variable depth core sampler  

DOEpatents

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

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

1996-01-01

327

Core-collapse Supernovae  

SciTech Connect

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

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

2013-01-01

328

The Core Diseasome.  

PubMed

Large amounts of protein-protein interaction (PPI) data are available. The human PPI network currently contains over 56?000 interactions between 11?100 proteins. It has been demonstrated that the structure of this network is not random and that the same wiring patterns in it underlie the same biological processes and diseases. In this paper, we ask if there exists a subnetwork of the human PPI network such that its topology is the key to disease formation and hence should be the primary object of therapeutic intervention. We demonstrate that such a subnetwork exists and can be obtained purely computationally. In particular, by successively pruning the entire human PPI network, we are left with a "core" subnetwork that is not only topologically and functionally homogeneous, but is also enriched in disease genes, drug targets, and it contains genes that are known to drive disease formation. We call this subnetwork the Core Diseasome. Furthermore, we show that the topology of the Core Diseasome is unique in the human PPI network suggesting that it may be the wiring of this network that governs the mutagenesis that leads to disease. Explaining the mechanisms behind this phenomenon and exploiting them remains a challenge. PMID:22820726

Janji?, Vuk; Pržulj, Nataša

2012-10-01

329

Core Vessel Insert Handling Robot for the Spallation Neutron Source  

SciTech Connect

The Spallation Neutron Source provides the world's most intense pulsed neutron beams for scientific research and industrial development. Its eighteen neutron beam lines will eventually support up to twenty-four simultaneous experiments. Each beam line consists of various optical components which guide the neutrons to a particular instrument. The optical components nearest the neutron moderators are the core vessel inserts. Located approximately 9 m below the high bay floor, these inserts are bolted to the core vessel chamber and are part of the vacuum boundary. They are in a highly radioactive environment and must periodically be replaced. During initial SNS construction, four of the beam lines received Core Vessel Insert plugs rather than functional inserts. Remote replacement of the first Core Vessel Insert plug was recently completed using several pieces of custom-designed tooling, including a highly complicated Core Vessel Insert Robot. The design of this tool are discussed.

Graves, Van B [ORNL; Dayton, Michael J [ORNL

2011-01-01

330

Evaluation of Analysis Techniques for Fluted-Core Sandwich Cylinders  

NASA Technical Reports Server (NTRS)

Buckling-critical launch-vehicle structures require structural concepts that have high bending stiffness and low mass. Fluted-core, also known as truss-core, sandwich construction is one such concept. In an effort to identify an analysis method appropriate for the preliminary design of fluted-core cylinders, the current paper presents and compares results from several analysis techniques applied to a specific composite fluted-core test article. The analysis techniques are evaluated in terms of their ease of use and for their appropriateness at certain stages throughout a design analysis cycle (DAC). Current analysis techniques that provide accurate determination of the global buckling load are not readily applicable early in the DAC, such as during preliminary design, because they are too costly to run. An analytical approach that neglects transverse-shear deformation is easily applied during preliminary design, but the lack of transverse-shear deformation results in global buckling load predictions that are significantly higher than those from more detailed analysis methods. The current state of the art is either too complex to be applied for preliminary design, or is incapable of the accuracy required to determine global buckling loads for fluted-core cylinders. Therefore, it is necessary to develop an analytical method for calculating global buckling loads of fluted-core cylinders that includes transverse-shear deformations, and that can be easily incorporated in preliminary design.

Lovejoy, Andrew E.; Schultz, Marc R.

2012-01-01

331

Recent Developments and Adaptations in Diamond Wireline Core Drilling Technology  

NASA Astrophysics Data System (ADS)

Scientific drilling using diamond wireline technology is presently undergoing a significant expansion and extension of activities that has allowed us to recover geologic samples that have heretofore been technically or financially unattainable. Under the direction and management of DOSECC, a high-capacity hybrid core drilling system was designed and fabricated for the Hawaii Scientific Drilling Project (HSDP) in 1998. This system, the DOSECC Hybrid Coring System (DHCS), has the capacity to recover H-sized core from depths of more than 6 km. In 1999, the DHCS completed the first phase of the HSDP to a depth of 3100 m at a substantially lower cost per foot than any previous scientific borehole to comparable depths and, in the process, established a new depth record for recovery of H-sized wireline core. This system has been offered for use in the Unzen Scientific Drilling Project, the Chicxulub (impact crater) Scientific Drilling Project, and the Geysers Deep Geothermal Reservoir Project. More recently, DOSECC has developed a smaller barge-mounted wireline core drilling system, the GLAD800, that is capable of recovering P-sized sediment core to depths of up to 800 m. The GLAD800 has been successfully deployed on Great Salt Lake and Bear Lake in Utah and is presently being mobilized to Lake Titicaca in South America for an extensive core recovery effort there. The coring capabilities of the GLAD800 system will be available to the global lakes drilling community for acquisition of sediment cores from many of the world's deep lakes for use in calibrating and refining global climate models. Presently under development by DOSECC is a heave-compensation system that will allow us to expand the capabilities of the moderate depth coring system to allow us to collect sediment and bottom core from the shallow marine environment. The design and capabilities of these coring systems will be presented along with a discussion of their potential applications for addressing a range of earth sciences questions.

Thomas, D. M.; Nielson, D. L.; Howell, B. B.; Pardey, M.

2001-05-01

332

Sneak in Some Core Subjects  

ERIC Educational Resources Information Center

Even if students don't have an aversion to core subjects, they may not see the relationship between the core subjects and their career path. In this article, the author outlines a career path project that can be adapted to work in any career and technical education (CTE) class to highlight the relationship between core subjects and the real world.…

Clarke, Lynne

2011-01-01

333

78 FR 56174 - In-Core Thermocouples at Different Elevations and Radial Positions in Reactor Core  

Federal Register 2010, 2011, 2012, 2013

...the adequacy of the AP1000 design and hydrogen control, the NRC regards this portion...reflooding an overheated core could generate hydrogen, at rates as high as 5.0 kg per second...the measured temperatures, the time evolution of the CET signal readings in the...

2013-09-12

334

Calculation methods for core distortions and mechanical behavior  

SciTech Connect

This paper describes ABADAN, a general purpose, nonlinear, multi-dimensional finite element structural analyses computer code developed for the express purpose of solving large nonlinear problems as typified by the Liquid Metal Fast Breeder Reactor (LMFBR) Core Restraint System design problem. All of the structural modeling features inherent in a general purpose finite element code and required to adequately model an LMFBR core restraint system are demonstrated. Typical results for a radial row and a sixty degree sector model of FFTF are presented. The sixty degree sector results are interpreted in terms of the design criteria that the core restraint system must satisfy. Extensions and adaptations of these modeling techniques to different core restraint design concepts can be readily achieved. 27 figures.

Sutherland, W.H.

1984-09-01

335

CANOPEN Controller IP Core  

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

336

Core 4: Image Bank  

NSDL National Science Digital Library

This Image Bank supplements the coursework for Core 4: The Shaping of the Modern World, an introductory course offered by the History Department of Brooklyn College. The Image Bank indexes numerous historical images spanning from the Scientific Revolution to the present. The images are divided into eight major topic indexes: Ancien Regime and Critics; Age of Revolutions; Industry and Society; Liberalism and Nationalism; Varieties of Imperialism; The World Turned Upside Down; Fascism, Depression & WWII; and, The World Since 1945. Indexes for major topics contain clustered subtopics, allowing users to locate relevant images quickly. This Image Bank presents students and educators with a valuable, visual method for understanding Modern Western History.

337

Hydraulic core cutting motor  

SciTech Connect

This patent describes an apparatus for drilling core cutting from the sidewall of a drill hole wherein the apparatus comprises an elongated housing with a hydraulic operated back-up shoe mounted within the housing for wedging the housing at a selected location in the drill hole and a hydraulic motor with a drilling bit connected thereto for rotation by the hydraulic motor and hydraulic means mounted within the housing and connected to the hydraulic motor for moving the bit into drilling engagement with the sidewall of the drill hole.

Kilmer, L.G.; Carter, J.W.

1987-11-24

338

Heterogeneous Multiprocessor System Design with ESPAM  

E-print Network

Heterogeneous Multiprocessor System Design with ESPAM: Integration of Hardware IP Cores MASTER . . . . . . . . . . . . . . . . . . . . . . . . . 9 2 Heterogeneous Multiprocessor System Generation 11 2.1 IP Core Integration in ESPAM­ Basic . . . . . . . . . . . . . . . . . . . . . . . . 54 3.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 #12;iv Contents 4

Emmerich, Michael

339

Design space exploration of photonic interconnects  

E-print Network

As processors scale deep into the multi-core and many-core regimes, bandwidth and energy-efficiency of the on-die interconnect network have become paramount design issues. Recognizing potential limits of electrical ...

Sun, Chen, S.M. Massachusetts Institute of Technology

2011-01-01

340

Acoustics in mechanical engineering undergraduate core courses: Challenges and opportunities  

NASA Astrophysics Data System (ADS)

Generally in an undergraduate curriculum of mechanical engineering, acoustics is not included as a core course. The major core courses deal with mechanics, design, dynamics of machinery, etc. However, engineering aspects of acoustics or noise can be included through elective courses. Given the limited slots for elective courses in a curriculum, it is difficult to run elective courses in acoustics regularly with a required number of students. The challenge is to find innovative ways to include acoustics into core courses so that all students are exposed to the field and its applications. The design and analysis of machine elements such as cams, gears, etc. are always part of core courses. It is in these contexts that the acoustics through noise aspects including multimedia can be introduced. Acoustics as an effect due to vibration as cause can be included in vibration analysis. A core course on system modeling can include acoustics. The integration of acoustical topics not only strengthens the core courses but also prepares the graduating engineer to deal with real problems better. Thus, it is important for academic acousticians to bring acoustics into the core courses. This paper presents some efforts to include the acoustics material in some core courses.

Prasad, M. G.

2005-04-01

341

Inner core structure caused by quasi-geostrophic core flows  

NASA Astrophysics Data System (ADS)

The Earth's inner-core has developed a significant degree of structural complexity since its formation around 1 Ga ago, epitomised by a top 100 km layer that is seismically slow in the western hemisphere and fast in the eastern. Establishing the cause of this hemispheric pattern has significant implications for the evolution of Earth's deep interior and the geodynamo process generating the Earth's magnetic field. Recent results from numerical geodynamo simulations suggest that fluid motions in the liquid outer core can induce heterogeneity at the inner-core boundary in broad agreement with the hemispheric seismic anomalies. The applicability of this mechanism to the present-day outer core has, however, never been established. In this work we show that the fluid motions inside the core can be used to estimate the induced lateral temperature anomalies at the inner-core surface. The flow in the outer core is assumed quasi-geostrophic and is obtained from its tangentially-geostrophic projection onto the core surface, derived from historical observations of the geomagnetic field and its variation with time. Over time, the imposed temperature anomalies lead to a pattern of crystal growth in the inner core which is in striking agreement with the observed hemispherical seismic pattern. In this manner, we link the independent geomagnetic and seismological datasets through a simple dynamical model of the outer core.

Silva, L.; Davies, C. J.; Mound, J. E.

2011-12-01

342

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

Microsoft Academic Search

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

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

2006-01-01

343

Tests of shale and coal cores from proposed spillway site, Shelbyville Reservoir, Kaskaskia River, Illinois  

Microsoft Academic Search

Thirteen shale cores and one coal core from the Shelbyville Reservoir spillway site were tested for shear strength, and the shale cores were tested for modulus of elasticity, effects of exposure to air, and bond to concrete to provide information for use in the spillway design study. (GRA)

Saucier

1964-01-01

344

Mode-Area Scaling of Helical-Core Dual-Clad Fiber Lasers and Amplifiers  

SciTech Connect

Helical-core, dual-clad fibers have been designed for single-mode operation with 60-um cores and 0.10 NA. Helical fibers are shown to perform where conventional coiled fibers cannot operate, with possible scaling to 200-um-diameter helical cores.

Jiang, Z.; Marciante, J.R.

2005-09-30

345

Structurally optimized sandwich panels with prismatic cores L. Valdevit a,*, J.W. Hutchinson b  

E-print Network

Structurally optimized sandwich panels with prismatic cores L. Valdevit a,*, J.W. Hutchinson b , A sandwich panels with corrugated and prismatic diamond cores have been analyzed and their behavior compared with panels designed using truss and honeycomb cores. Failure mechanism maps have been devised that account

Hutchinson, John W.

346

Development of Air Core Type 500 kV HV Pulse Transformer  

Microsoft Academic Search

Cylindrical type air core pulse transformers capable of passing high voltage and energy pulse waveforms with high efficiency and low distortion require a much more delicate design balance of physical dimensions and electrical parameters than iron or ferrite core units. The structure of an air core high voltage pulse transformer is relatively simple, but considerable attention is needed to prevent

S. C. Kim; S. S. Park; S. H. Kim; H. Heo; S. H. Nam; S. T. Ko

2005-01-01

347

Vibration and sound radiation from a sandwich cylindrical shell with prismatic core  

Microsoft Academic Search

The vibration and the sound radiation of cylindrical shells with cellular core is here analyzed. The considered structure is composed of a repeated unit cell and can be classified as a Linear Cellular Alloy (LCA) core. The unit cells are of a tetrahedral configuration, arranged according to a honeycomb lay-out. The considered configuration has previously been proposed for core designs

Sang M. Jeong; Massimo Ruzzene

2004-01-01

348

TU Electric's core model  

SciTech Connect

In 1985, prior to the completion of its nuclear power plant, Texas Utilities (TU) Electric established a corporate commitment to develop and license a fuel vendor-independent reactor analysis capability. Since TU Electric had no nuclear operating plants at that time, the analytical tools were selected without the benefit of comparisons of calculated results to measured data from TU Electric plants. After selection of the code package, reactor models were developed and bench-marked against measured data from two operating pressurized water reactors (PWRs). These benchmarks, along with the results of pin-cell and small-core analyses, formed the bases of a topical report submitted to the US Nuclear Regulatory Commission (NRC) in mid-1989. Included with that NRC submittal were predictions of Comanche Peak Steam Electric Station (CPSES) low-power physics tests results and other physics parameters routinely measured during power operation. The results of recent CPSES initial start-up tests as well as data obtained during power ascension testing continue to validate the high reliability of the three-dimensional nodal core model developed by TU Electric.

Killgore, M.R.; Janne, R.L.; Husain, A. (Texas Utilities, Dallas (United States))

1990-01-01

349

Distribution of Core Oligosaccharide Types in Lipopolysaccharides from Escherichia coli  

PubMed Central

In the lipopolysaccharides of Escherichia coli there are five distinct core oligosaccharide (core OS) structures, designated K-12 and R1 to R4. The objective of this work was to determine the prevalences of these core OS types within the species. Unique sequences in the waa (core OS biosynthesis) gene operon were used to develop a PCR-based system that facilitated unequivocal determination of the core OS types in isolates of E. coli. This system was applied to the 72 isolates in the E. coli ECOR collection, a compilation of isolates that is considered to be broadly representative of the genetic diversity of the species. Fifty (69.4%) of the ECOR isolates contained the R1 core OS, 8 (11.1%) were representatives of R2, 8 (11.1%) were R3, 2 (2.8%) were R4, and only 4 (5.6%) were K-12. R1 is the only core OS type found in all four major phylogenetic groups (A, B1, B2, and D) in the ECOR collection. Virulent extraintestinal pathogenic E. coli isolates tend to be closely related to group B2 and, to a lesser extent, group D isolates. All of the ECOR representatives from the B2 and D groups had the R1 core OS. In contrast, commensal E. coli isolates are more closely related to group A, which contains isolates representing each of the five core OS structures. R3 was the only core OS type found in 38 verotoxigenic E. coli (VTEC) isolates from humans and cattle belonging to the common enterohemorrhagic E. coli serogroups O157, O111, and O26. Although isolates from other VTEC serogroups showed more core OS diversity, the R3 type (83.1% of all VTEC isolates) was still predominant. When non-VTEC commensal isolates from cattle were analyzed, it was found that most possessed the R1 core OS type. PMID:10678915

Amor, Karen; Heinrichs, David E.; Frirdich, Emilisa; Ziebell, Kim; Johnson, Roger P.; Whitfield, Chris

2000-01-01

350

Safety design of prototype fast breeder reactor  

SciTech Connect

The basic design and safety design of Prototype Fast Breeder Reactor (PFBR) is presented. Design aspects covered include safety classification, seismic categorization, design basis conditions, design safety limits, core physics, core monitoring, shutdown system, decay heat removal system, protection against sodium leaks and tube leaks in steam generator, plant layout, radiation protection, event analysis, beyond design basis accidents, integrity of primary containment, reactor containment building and design pressure resulting from core disruptive accident. The measures provided in the design represent a robust case of the safety of the reactor. (authors)

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

2004-07-01

351

Implement of time division multiplexing high speed programmable Viterbi decoder IP core  

NASA Astrophysics Data System (ADS)

The programmable Time Division multiplexing high Viterbi decoder IP core is studied in this paper. According to the characteristics of multiple communication system, the method of programmable time-division multiplexing is puts forward, the high-performance and less resource occupy IP core is designed. Based on SMIC 0.18um CMOS technology, the ASIC of IP core is test. The test results show that the IP core areas, power and frequency could satisfy demand of real-time communication.

Wu, Lan; Chen, Qiliang

2013-03-01

352

SPEAR3 Gradient Dipole Core Fabrication  

SciTech Connect

Traditional means of core fabrication are to glue the laminations or weld them to form the yoke structure. These means result in good yoke assemblies for shorter (<0.6m) magnets. However, because of weld distortions or mechanical strength limitations, welding and/or gluing techniques are difficult to gain high mechanical precision for longer cores. The SPEAR3 gradient dipoles are up to 1.45m long and require distortions of <0.05mm. Therefore, the SPEAR3 gradient dipole core design incorporated an assembly technique, originally devised for the PEPII insertion quadrupoles and later adapted for the ALS gradient magnets. This technique involved fabricating a rigid frame for the core, precisely stacking and compressing the laminations using hydraulic jacks and granite surfaces and straight edges, and fixing the laminations in the frame by filling the grooves between the laminations and frame using steel loaded epoxy. Although this technique has been used in the past, it has never been fully described and published. This paper is written to provide a detailed description of the procedure and to present measurement data demonstrating the mechanical precision and stiffness of the resulting product.

Li, Nanyang

2003-07-29

353

Fabricating the Solid Core Heatpipe Reactor  

NASA Astrophysics Data System (ADS)

The solid core heatpipe nuclear reactor has the potential to be the most dependable concept for the nuclear space power system. The design of the conversion system employed permits multiple failure modes instead of the single failure mode of other concepts. Regardless of the material used for the reactor, either stainless steel, high-temperature alloys, Nb1Zr, Tantalum Alloys or MoRe Alloys, making the solid core by machining holes in a large diameter billet is not satisfactory. This is because the large diameter billet will have large grains that are detrimental to the performance of the reactor due to grain boundary diffusion. The ideal fabrication method for the solid core is by hot isostatic pressure diffusion bonding, (HIPing). By this technique, wrought fine-grained tubes of the alloy chosen are assembled into the final shape with solid cusps and seal welded so that there is a vacuum in between all surfaces to be diffusion bonded. This welded structure is then HIPed for diffusion bonding. A solid core made of Type 321 stainless steel has been satisfactorily produced by Advanced Methods and Materials and is undergoing evaluation by NASA Marshall Space Flight Center.

Ring, Peter J.; Sayre, Edwin D.; Houts, Mike

2006-01-01

354

Growth outside the core.  

PubMed

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

Zook, Chris; Allen, James

2003-12-01

355

Nanocomposite plasmonic fluorescence emitters with core/shell configurations.  

SciTech Connect

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

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

2010-06-01

356

Research of UMTS core network firewall base on IXP1200  

NASA Astrophysics Data System (ADS)

The 3G network security was a problem in the practice. The particularity of the 3G core network determined that the new firewall technology must be adopt in order to protect the core network. The development of the network processor (NP) technology offered a high-performance realization platform for core network firewall. On the basis analyzing the shelter method of the attack to each interface in the 3G core network, a scheme of 3G core network firewall design was put forward. It was on the network processor hardware platform. How to use IPSEC protocol to protect the GPRS tunnel protocol (GTP) and implement on the NP was discussed in detail. The aggregated bit vector algorithm was applied on NP for packet classification. In the end result table of firewall performance test with SMART BIT instrument was provided.

Peng, Kai; Deng, Tian Ping; Lu, YiMin

2005-12-01

357

Cryptographic rights management of FPGA intellectual property cores  

Microsoft Academic Search

As the capacity of FPGA's increases to millions of equivalent gates the use of Intellectual Property (IP) cores becomes increasingly important to control design complexity. FPGA's are becoming platforms for integrating a system solution from components supplied by independent vendors in the same way as printed circuit boards provided a platform for earlier generations of designers. However, the current commercial

Tom Kean

2002-01-01

358

Static Aeroelastic Response of Chiral-core Airfoils  

Microsoft Academic Search

Extensive research is being devoted to the analysis and application of cellular solids for the design of innovative structural components. The chiral geometry in particular features a unique mechanical behavior which is here exploited for the design of 2D airfoils with morphing capabilities. A coupled-physics model, comprising computational fluid dynamics and structural analyses, investigates the influence of the chiral core

A. Spadoni; M. Ruzzene

2007-01-01

359

Sandia in-core molten fuel pool experiment results  

Microsoft Academic Search

The major initial objective of the in-core molten fuel pool program at Sandia has been to develop a versatile experiment in which relative heat fluxes and structural ablation could be studied using real materials under typical temperature and heating conditions. The initial experiment series is designed to prove containment design, test ultrasonic thermometers, and provide material interaction data. The first

H. G. Plein; G. A. Carlson

1977-01-01

360

GPM Core Observatory Launch Animation  

NASA Video Gallery

This animation depicts the launch of the Global Precipitation Measurement (GPM) Core Observatory satellite from Tanegashima Space Center, Japan. The launch is currently scheduled for Feb. 27, 2014....

361

One-dimensional mesoporous Fe2O3@TiO2 core-shell nanocomposites: Rational design, synthesis and application as high-performance photocatalyst in visible and UV light region  

NASA Astrophysics Data System (ADS)

An ideal photocatalyst for degradation of organic pollutants should combine the features of efficient visible light response, fast electron transport, high electron-hole separation efficiency, and large specific surface area. However, these requirements usually cannot be achieved simultaneously in the present state-of-the-art research. In this work, we develop a rational synthesis strategy for the preparation of one-dimensional (1D) mesoporous Fe2O3@TiO2 core-shell composites. In this strategy, FeOOH nanorods are firstly coated by TiO2 shell, followed by a calcination process. The as-prepared composites are thoroughly investigated with X-ray powder diffraction, scanning electron microscope, energy dispersive spectroscopy, transmission electron microscope, N2 adsorption-desorption isotherms, UV-visible diffuse-reflectance spectra, and photoluminescence spectra. Endowed with the advantages of its composition and specific structural features, the presented sample possesses the combined advantages mentioned above, thus delivering evidently enhanced photocatalytic activity for the degradation of methyl orange under UV light irradiation and Rhodamine B under visible light irradiation. And the possible mechanism of the enhanced photocatalytic performance is proposed.

Zhang, Xiao; Xie, Yaping; Chen, Haoxin; Guo, Jinxue; Meng, Alan; Li, Chunfang

2014-10-01

362

Isentropic Finite Volume Dynamical Core  

NASA Astrophysics Data System (ADS)

Numerous studies have demonstrated that vertical discretizations of atmospheric general circulation models have a significant impact on the characteristics of tracer transport and atmospheric dynamics. The NCAR Finite Volume (FV) dynamical core employs quasi-Lagrangian surfaces in the vertical which reduces all advective processes of the governing equations to 2D. Vertical transport is accounted for by an occasional remapping process to a set of layers defined by coordinate surfaces that are a function of pressure and surface pressure (a "hybrid coordinate" formulation). Although this model has quite desirable transport properties compared to many other formulations, we believe that some of the less desirable properties are attributable to the remapping to the hybrid pressure coordinate layers. A very desirable feature for the vertical discretization is that the Lagrangian model surfaces are defined by a conserved variable. Under adiabatic and inviscid processes in the atmosphere, potential temperature is conserved following the motion of fluid and isentropic surfaces correspond to material coordinates. In this study, we implement a hybrid isentropic vertical coordinate in the FV model. We will address the consequence of changing the model vertical discretization. The performance of the isentropic FV model is first assessed by conducting an idealized adiabatic baroclinic wave test case. Secondly, a suite of tests designed to examine the model behavior on tracer transport are performed. Finally, the climatology simulated by the new isentropic FV model coupled with full physics will be presented and compared with that carried out with the hybrid-pressure FV model.

Chen, C.; Rasch, P. J.; Nair, R. D.; Tufo, H. M.

2006-12-01

363

The practice of design is at the central core of engineering. While the basic sciences are concerned with the discovery of new knowledge, engineering is concerned with the application  

E-print Network

, a difficult but immensely rewarding task. Our curriculum is dedicated to providing graduates with a strong computer based graphical tools, which are taught in these courses. A series of projects are also used of these fundamental concepts in most of these courses. Design projects and/or open-ended homework problems are used

Chini, Gregory P.

364

Ice Core Dating Software for Interactive Dating of Ice Cores  

Microsoft Academic Search

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

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

2005-01-01

365

A New Design Approach for Axial-Field Electrical Machines  

Microsoft Academic Search

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

Wai Leung; James C. Chan

1980-01-01

366

A method for reducing encapsulation stress to ferrite pot cores  

SciTech Connect

This paper describes a method of reducing the mechanical stress caused when a ferrite pot core is encapsulated in a rigid epoxy. the stresses are due to the differences of coefficient of thermal expansion between the two materials. A stress relief medium, phenolic micro-balloon-filled, syntactic polysulfide, is molded into the shape of the pot core. The molded polysulfide is bonded to the core prior to encapsulation. The new package design has made a significant difference in the ability to survive temperature cycles.

Sanchez, R.O.

1994-08-01

367

Heterotrimeric Coiled Coils with Core Residue Urea Side Chains  

PubMed Central

We report several coiled coil heterotrimers with varying core residue buried polar groups, all with Tm values > 43° C. Introduction of new synthetic side chain structures, including some terminating in mono-substituted ureas, diversifies the pool of viable core residue candidates. A study of core charge pairings demonstrates that, unlike dimeric systems, trimeric coiled coils do not tolerate guanidine-guanidine contacts, even in the presence of a compensating carboxylate. Overall, the roster of feasible coiled coil designs is significantly expanded. PMID:19032043

Diss, Maria L.; Kennan, Alan J.

2009-01-01

368

THz propagation in kagome hollow-core microstructured fibers.  

PubMed

We demonstrate single mode terahertz (THz) guidance in hollow-core kagome microstructured fibers over a broad frequency bandwidth. The fibers are characterized using a THz time-domain spectroscopy (THz-TDS) setup, incorporating specially designed THz lenses to achieve good mode overlap with the fundamental mode field distribution. Losses 20 times lower than the losses of the fiber material are observed in the experiments, as well as broad frequency ranges of low dispersion, characteristic of hollow-core fibers. PMID:21935215

Anthony, Jessienta; Leonhardt, Rainer; Leon-Saval, Sergio G; Argyros, Alexander

2011-09-12

369

Detection of stator core faults in large turbo-generators  

Microsoft Academic Search

Many large turbo-generators today are now operating beyond their design lifetime, with careful condition-based maintenance and operation having extended their life expectancy. Monitoring the health of large turbo-generators is now an integral part of their operation. This paper describes the use of non-invasive electromagnetic sensors to detect core inter-lamination insulation faults in the stator cores of large turbo-generators before they

A. C. Smith; D. Bertenshaw; C. W. Ho; T. Chan; M. Sasic

2009-01-01

370

MOX fuel arrangement for nuclear core  

DOEpatents

In order to use up a stockpile of weapons-grade plutonium, the plutonium is converted into a mixed oxide (MOX) fuel form wherein it can be disposed in a plurality of different fuel assembly types. Depending on the equilibrium cycle that is required, a predetermined number of one or more of the fuel assembly types are selected and arranged in the core of the reactor in accordance with a selected loading schedule. Each of the fuel assemblies is designed to produce different combustion characteristics whereby the appropriate selection and disposition in the core enables the resulting equilibrium cycle to closely resemble that which is produced using urania fuel. The arrangement of the MOX rods and burnable absorber rods within each of the fuel assemblies, in combination with a selective control of the amount of plutonium which is contained in each of the MOX rods, is used to tailor the combustion characteristics of the assembly. 38 figs.

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

1998-10-13

371

MOX fuel arrangement for nuclear core  

DOEpatents

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

Kantrowitz, Mark L. (Portland, CT); Rosenstein, Richard G. (Windsor, CT)

2001-07-17

372

Core Competencies for Injury and Violence Prevention  

PubMed Central

Efforts to reduce the burden of injury and violence require a workforce that is knowledgeable and skilled in prevention. However, there has been no systematic process to ensure that professionals possess the necessary competencies. To address this deficiency, we developed a set of core competencies for public health practitioners in injury and violence prevention programs. The core competencies address domains including public health significance, data, the design and implementation of prevention activities, evaluation, program management, communication, stimulating change, and continuing education. Specific learning objectives establish goals for training in each domain. The competencies assist in efforts to reduce the burden of injury and violence and can provide benchmarks against which to assess progress in professional capacity for injury and violence prevention. PMID:19197083

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

2009-01-01

373

Next Generation CANDU Core Physics Innovations  

SciTech Connect

NG CANDU is the 'Next Generation' CANDU{sup R} reactor, aimed at producing electrical power at a capital cost significantly less than that of the current reactor designs. A key element of cost reduction is the use of H{sub 2}O as coolant and Slightly Enriched Uranium fuel in a tight D{sub 2}O-moderated lattice. The innovations in the CANDU core physics result in substantial improvements in economics as well as significant enhancements in reactor licensability, controllability, and waste reduction. The full-core coolant-void reactivity in NG CANDU is about -3 mk. Power coefficient is substantially negative. Fuel burnup is about three times the current natural-uranium burnup. (authors)

Chan, P.S.W.; Hopwood, J.M.; Love, J.W. [Atomic Energy of Canada Ltd., Ontario (Canada)

2002-07-01

374

Mox fuel arrangement for nuclear core  

DOEpatents

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

Kantrowitz, Mark L. (Portland, CT); Rosenstein, Richard G. (Windsor, CT)

2001-05-15

375

Business Planning Core Facilities  

PubMed Central

Thoughtful business planning is pivotal to the success of any business/operational venture. When planned in a thoughtful and detailed manner there are very few operational or financial surprises for an institution or facility (service center) to contend with. At Stony Brook Medicine we include SWOT analysis and a detailed Market Analysis as part of the process. This is bolstered by an initiative to ensure institutional policies are met so that facilities remain in compliance throughout their lifecycle. As we operate 14 facilities we have had the opportunity to become creative in our approach to coordinate activities, virtualize services, integrate new software business-to-business partners, and finally coordinate plans for phased consolidation instead of outright termination of services when required. As the Associate Dean for Scientific Operations and Research Facilities, the shared research facilities (cores) of the Medical School are in my direct line of sight. We understand their value to the meeting our overall research mission. We have found that an active process of monitoring to predict trouble as much as possible is the best approach for facilities. Some case analysis of this type of interaction will be presented as well.

Itzkowitz, G.N.

2014-01-01

376

The Noncommutative Bion Core  

E-print Network

We examine new noncommutative solutions of the nonabelian theory on the world-volume of N coincident D-strings. These solutions can be interpreted in terms of noncommutative geometry as funnels describing the nonabelian D-string expanding out into an orthogonal D3-brane. These configurations are `dual' to the bion solutions in the abelian world-volume theory of the D3-brane. In the latter, an charge N magnetic monopole describes N D-strings attached to the D3-brane with a spike deformation of the world-volume. The noncommutative D-string solutions give a reliable account of physics at the core of the monopole, where the bion description is expected to breakdown. In the large N limit, we find good agreement between the two points of view, including the energy, couplings to background fields, and the shape of the funnel. We also study fluctuations traveling along the D-string, again obtaining agreement in the large N limit. At finite N, our results give a limit on the number of modes that can travel to infinity...

Constable, N R; Tafjord, O Yu; Constable, Neil R.; Myers, Robert C.; Tafjord, Oyvind

2000-01-01

377

Determination of optimal core fissile loadings in the TREAT Upgrade reactor  

Microsoft Academic Search

The TREAT Upgrade (TU) reactor design is presently nearing completion. The reactor will be used to test LMFBR fuel under simulated accident conditions. The physics of the TU core is complicated by a number of factors related to the planned application of the facility. In this paper the design approach used to produce the core fissile loading spatial distribution needed

S. K. Bhattacharyya; R. M. Lell; A. J. Ulrich; S. Yang

1983-01-01

378

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

SciTech Connect

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

Robert L. Bratton; Tim D. Burchell

2005-08-01

379

The EPOS Integrated Core Services  

NASA Astrophysics Data System (ADS)

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

Jeffery, Keith; Michelini, Alberto; Bailo, Daniele

2013-04-01

380

Common Core: Victory Is Yours!  

ERIC Educational Resources Information Center

In this article, the author discusses how to implement the Common Core State Standards in the classroom. She presents examples and activities that will leave teachers feeling "rosy" about tackling the new standards. She breaks down important benchmarks and shows how other teachers are doing the Core--and loving it!

Fink, Jennifer L. W.

2012-01-01

381

Connecticut's Common Core of Learning.  

ERIC Educational Resources Information Center

Since its adoption in January 1987, Connecticut's Common Core of Learning has set the standard of an educated citizen for the state, and the five 1991-1995 Statewide Educational Goals for Students incorporate its policy on the skills, knowledge and attitudes that are expected of Connecticut's public secondary school graduates. The Common Core

Connecticut State Dept. of Education, Hartford. Bureau of Curriculum and Instruction.

382

Core percolation on complex networks  

NASA Astrophysics Data System (ADS)

As a fundamental structural transition in complex networks, core percolation is related to a wide range of important problems, including combinatorial optimizations and network controllability. Yet, previous theoretical studies of core percolation have been focusing on the classical Erdos-Rényi random networks with Poisson degree distribution, which are quite unlike many real-world networks with scale-free or fat-tailed degree distributions. Here we show that core percolation can be analytically studied for complex networks with arbitrary degree distributions. We derive the condition for core percolation and find that purely scale-free networks have no core for any degree exponents. We show that for undirected networks if core percolation occurs then it is always continuous while for directed networks it becomes discontinuous (and hybrid) if the in- and out-degree distributions differ. We also find that core percolations on undirected and directed networks have completely different critical exponents associated with their critical singularities. Finally, we apply our theory to real-world directed networks and find, surprisingly, that they often have much larger core sizes as compared to random models.

Liu, Yang-Yu; Csóka, Endre; Zhou, Haijun; Pósfai, Márton

2013-03-01

383

The Common Core Takes Hold  

ERIC Educational Resources Information Center

A survey administered in the spring of 2013 by the Center on Education Policy (CEP) inquired into the implementation of Common Core State Standards at that time. Based on self-reports by state officials, the survey found that curricula aligned to the common core were already being taught in at least some districts or grade levels. All states…

Rothman, Robert

2014-01-01

384

Understanding Common Core State Standards  

ERIC Educational Resources Information Center

Now that the Common Core standards are coming to just about every school, what every school leader needs is a straightforward explanation that lays out the benefits of the Common Core in plain English, provides a succinct overview, and gets everyone thinking about how to transition to this promising new paradigm. This handy, inexpensive booklet…

Kendall, John S.

2011-01-01

385

Rotation of the Inner Core  

Microsoft Academic Search

We cannot observe the magnetic field inside the earth's core directly, but there is likely to be a large toroidal part of 10-100 Gauss which, together with the dipole component, could produce a magnetic torque on the inner core that tends to rotate it. Estimates based on dynamo calculations give torques of 10 --N m which is large enough to

D. Gubbins

1981-01-01

386

An Ensemble of Turbulent Cores  

NASA Astrophysics Data System (ADS)

We present preliminary results from 50 smoothed particle hydrodynamics (SPH) simulations of weakly turbulent cores of molecular gas with turbulent Mach number 0.2, radius 0.13 pc and mass 5×M?. We use the SEREN code which includes self-gravity and sink particles to model protostars. We use a barotropic equation of state and do not include magnetic fields or radiative transfer due to computational limitations. The cores collapse and fragment, forming protostars; we examine their mass function and binary properties. Each core produces approximately 4 stars with a core mass to star mass efficiency of 25%. The system multiplicity is approximately 40%; cores may produce more than one multiple system.

McLeod, Andrew; Chabrier, Gilles

2013-07-01

387

Spacecraft transformer and inductor design  

NASA Technical Reports Server (NTRS)

The conversion process in spacecraft power electronics requires the use of magnetic components which frequently are the heaviest and bulkiest items in the conversion circuit. This handbook pertains to magnetic material selection, transformer and inductor design tradeoffs, transformer design, iron core dc inductor design, toroidal power core inductor design, window utilization factors, regulation, and temperature rise. Relationships are given which simplify and standardize the design of transformers and the analysis of the circuits in which they are used. The interactions of the various design parameters are also presented in simplified form so that tradeoffs and optimizations may easily be made.

Mclyman, W. T.

1977-01-01

388

Gas core reactors for actinide transmutation and breeder applications  

NASA Technical Reports Server (NTRS)

This work consists of design power plant studies for four types of reactor systems: uranium plasma core breeder, uranium plasma core actinide transmuter, UF6 breeder and UF6 actinide transmuter. The plasma core systems can be coupled to MHD generators to obtain high efficiency electrical power generation. A 1074 MWt UF6 breeder reactor was designed with a breeding ratio of 1.002 to guard against diversion of fuel. Using molten salt technology and a superheated steam cycle, an efficiency of 39.2% was obtained for the plant and the U233 inventory in the core and heat exchangers was limited to 105 Kg. It was found that the UF6 reactor can produce high fluxes (10 to the 14th power n/sq cm-sec) necessary for efficient burnup of actinide. However, the buildup of fissile isotopes posed severe heat transfer problems. Therefore, the flux in the actinide region must be decreased with time. Consequently, only beginning-of-life conditions were considered for the power plant design. A 577 MWt UF6 actinide transmutation reactor power plant was designed to operate with 39.3% efficiency and 102 Kg of U233 in the core and heat exchanger for beginning-of-life conditions.

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

1978-01-01

389

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

PubMed

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

Zhang, Chao; Lee, Jim Yang

2013-05-28

390

Radiation Effects: Core Project  

NASA Technical Reports Server (NTRS)

The risks to personnel in space from the naturally occurring radiations are generally considered to be one of the most serious limitations to human space missions, as noted in two recent reports of the National Research Council/National Academy of Sciences. The Core Project of the Radiation Effects Team for the National Space Biomedical Research Institute is the consequences of radiations in space in order to develop countermeasure, both physical and pharmaceutical, to reduce the risks of cancer and other diseases associated with such exposures. During interplanetary missions, personnel in space will be exposed to galactic cosmic rays, including high-energy protons and energetic ions with atomic masses of iron or higher. In addition, solar events will produce radiation fields of high intensity for short but irregular durations. The level of intensity of these radiations is considerably higher than that on Earth's surface, and the biological risks to astronauts is consequently increased, including increased risks of carcinogenesis and other diseases. This group is examining the risk of cancers resulting from low-dose, low-dose rate exposures of model systems to photons, protons, and iron by using ground-based accelerators which are capable of producing beams of protons, iron, and other heavy ions at energies comparable to those encountered in space. They have begun the first series of experiments using a 1-GeV iron beam at the Brookhaven National Laboratory and 250-MeV protons at Loma Linda University Medical Center's proton synchrotron facility. As part of these studies, this group will be investigating the potential for the pharmaceutical, Tamoxifen, to reduce the risk of breast cancer in astronauts exposed to the level of doses and particle types expected in space. Theoretical studies are being carried out in a collaboration between scientists at NASA's Johnson Space Center and Johns Hopkins University in parallel with the experimental program have provided methods and predictions which are being used to assess the levels of risks to be encountered and to evaluate appropriate strategies for countermeasures. Although the work in this project is primarily directed toward problems associated with space travel, the problem of protracted exposures to low-levels of radiation is one of national interest in our energy and defense programs, and the results may suggest new paradigms for addressing such risks.

Dicello, John F.

1999-01-01

391

Experimental Constraints on Core Composition  

NASA Astrophysics Data System (ADS)

The Earth's core was discovered in 1906, when Oldham inferred the existence of a low-velocity region inside the Earth from changes in the amplitude of compressional waves traveling through the Earth's interior (Oldham, 1906). Over the last century, a wealth of knowledge has been obtained on the nature and dynamics of the core ( Figure 1; Dziewonski and Anderson, 1981; Stacey, 1992). Residing in the center of the planet, the core has a radius of 3,480 km, more than half of the Earth's radius. It occupies roughly one-eighth of the Earth's volume, and accounts for nearly one-third of its mass. The mass fraction in the core is much higher than its volume fraction, because the density in the core is much higher than that of the mantle ( Figure 2). With the density jumping from 5.5 g cm-3 to 9.9 g cm-3, the density contrast at the core-mantle boundary (CMB) is the largest in the whole planet. Based on analyses of the velocity and attenuation of seismic waves, the core has been established to have a layered structure. The central part comprising less than 5% of the core's mass or volume is solid, while the rest is largely molten. The pressure in the core ranges from 136 GPa (1,380 kbar) at the CMB to 360 GPa at the very center. In order to stay in the liquid state under such high pressures, the temperature in the core must be high as well. The temperature of the liquid-solid interface at the inner-outer core boundary (ICB) is estimated at 5,400±400 K (e.g., Brown and McQueen, 1986; Boehler, 2000; Hemley and Mao, 2001). (5K)Figure 1. Cross-section of the Earth showing its layered structure (source Dziewonski and Anderson, 1981). (6K)Figure 2. Preliminary reference Earth model (PREM) (source Dziewonski and Anderson, 1981). Combining geochemical and seismological observations on the Earth with laboratory measurements on relevant materials, more than 80 wt.% of the core has been deduced to consist of iron. Other elements with significant concentrations in the core include nickel (˜5 wt.%) and one or more elements that are lighter than iron (e.g., Stevenson, 1981; Jacobs, 1987; Jeanloz, 1990). The age of the core has been determined using isotope geochronometers. According to the most recent measurements based on tungsten-hafnium systematics, most of the core-mantle segregation took place in less than 30Myr ( Yin et al., 2002; Kleine et al., 2002). In other words, the core is almost as old as the Earth itself. Core formation occurred as soon as the Earth accreted, or simultaneously with accretion.Despite its old age, the core is dynamically active. The geomagnetic field observed on the Earth's surface is believed to originate in the outer core through the convection of the liquid conductive metal (Jacobs, 1987). A number of observations have been made recently that are indicative of chemical reaction and dynamical coupling between the core and the mantle (e.g., Lay et al., 1998). Moreover, the core is widely accepted to be a major energy source for our planet. Not only did it acquire a large amount of energy early on during core-mantle segregation from radioactive decay of short-life isotopes, but it is also capable of producing more heat through solidification of the liquid outer core. Speculation suggests that the core contains a significant amount of potassium, which could have been generating heat over the history of the Earth (e.g., Jacobs, 1987; see Chapter 2.15).The surface of the core is only 2,900 km in depth. However, drilling into the Earth's interior turns out to be much more challenging than flying into outer space. Spacecrafts have reached Jupiter, more than 600 million km away from the Earth, but the deepest hole we have successfully drilled has reached less than 14 km below the Earth's surface. Volcanic eruptions are unlikely to bring up pristine samples of the core to the surface of the Earth. To date, the most direct observations of the core have come from seismological studies using remote-sensing techniques. Due to the complex structure of the Earth's interior, seismic investigations require extensive data cove

Li, J.; Fei, Y.

2003-12-01

392

Characterizing Facesheet/Core Disbonding in Honeycomb Core Sandwich Structure  

NASA Technical Reports Server (NTRS)

Results are presented from an experimental investigation into facesheet core disbonding in carbon fiber reinforced plastic/Nomex honeycomb sandwich structures using a Single Cantilever Beam test. Specimens with three, six and twelve-ply facesheets were tested. Specimens with different honeycomb cores consisting of four different cell sizes were also tested, in addition to specimens with three different widths. Three different data reduction methods were employed for computing apparent fracture toughness values from the test data, namely an area method, a compliance calibration technique and a modified beam theory method. The compliance calibration and modified beam theory approaches yielded comparable apparent fracture toughness values, which were generally lower than those computed using the area method. Disbonding in the three-ply facesheet specimens took place at the facesheet/core interface and yielded the lowest apparent fracture toughness values. Disbonding in the six and twelve-ply facesheet specimens took place within the core, near to the facesheet/core interface. Specimen width was not found to have a significant effect on apparent fracture toughness. The amount of scatter in the apparent fracture toughness data was found to increase with honeycomb core cell size.

Rinker, Martin; Ratcliffe, James G.; Adams, Daniel O.; Krueger, Ronald

2013-01-01

393

Uncovering the information core in recommender systems  

PubMed Central

With the rapid growth of the Internet and overwhelming amount of information that people are confronted with, recommender systems have been developed to effectively support users' decision-making process in online systems. So far, much attention has been paid to designing new recommendation algorithms and improving existent ones. However, few works considered the different contributions from different users to the performance of a recommender system. Such studies can help us improve the recommendation efficiency by excluding irrelevant users. In this paper, we argue that in each online system there exists a group of core users who carry most of the information for recommendation. With them, the recommender systems can already generate satisfactory recommendation. Our core user extraction method enables the recommender systems to achieve 90% of the accuracy of the top-L recommendation by taking only 20% of the users into account. A detailed investigation reveals that these core users are not necessarily the large-degree users. Moreover, they tend to select high quality objects and their selections are well diversified. PMID:25142186

Zeng, Wei; Zeng, An; Liu, Hao; Shang, Ming-Sheng; Zhou, Tao

2014-01-01

394

Uncovering the information core in recommender systems  

NASA Astrophysics Data System (ADS)

With the rapid growth of the Internet and overwhelming amount of information that people are confronted with, recommender systems have been developed to effectively support users' decision-making process in online systems. So far, much attention has been paid to designing new recommendation algorithms and improving existent ones. However, few works considered the different contributions from different users to the performance of a recommender system. Such studies can help us improve the recommendation efficiency by excluding irrelevant users. In this paper, we argue that in each online system there exists a group of core users who carry most of the information for recommendation. With them, the recommender systems can already generate satisfactory recommendation. Our core user extraction method enables the recommender systems to achieve 90% of the accuracy of the top-L recommendation by taking only 20% of the users into account. A detailed investigation reveals that these core users are not necessarily the large-degree users. Moreover, they tend to select high quality objects and their selections are well diversified.

Zeng, Wei; Zeng, An; Liu, Hao; Shang, Ming-Sheng; Zhou, Tao

2014-08-01

395

Core compressor exit stage study, 2  

NASA Technical Reports Server (NTRS)

A total of two three-stage compressors were designed and tested to determine the effects of aspect ratio on compressor performance. The first compressor was designed with an aspect ratio of 0.81; the other, with an aspect ratio of 1.22. Both compressors had a hub-tip ratio of 0.915, representative of the rear stages of a core compressor, and both were designed to achieve a 15.0% surge margin at design pressure ratios of 1.357 and 1.324, respectively, at a mean wheel speed of 167 m/sec. At design speed the 0.81 aspect ratio compressor achieved a pressure ratio of 1.346 at a corrected flow of 4.28 kg/sec and an adiabatic efficiency of 86.1%. The 1.22 aspect ratio design achieved a pressure ratio of 1.314 at 4.35 kg/sec flow and 87.0% adiabatic efficiency. Surge margin to peak efficiency was 24.0% with the lower aspect ratio blading, compared with 12.4% with the higher aspect ratio blading.

Behlke, R. F.; Burdsall, E. A.; Canal, E., Jr.; Korn, N. D.

1979-01-01

396

Quiet Clean Short-Haul Experimental Engine (QCSEE). Preliminary analyses and design report, volume 2  

NASA Technical Reports Server (NTRS)

The experimental and flight propulsion systems are presented. The following areas are discussed: engine core and low pressure turbine design; bearings and seals design; controls and accessories design; nacelle aerodynamic design; nacelle mechanical design; weight; and aircraft systems design.

1974-01-01

397

A Treasure Chest of Cores  

NSDL National Science Digital Library

Over the years, the combined ocean drilling programs (Deep Sea Drilling Project, Ocean Drilling Program, and Integrated Ocean Drilling Program) have recovered thousands of cores from beneath the ocean floor. Students can study a brief synopsis of some of the most important discoveries made from these cores by clicking on an interactive map which shows sampling locations where major discoveries were made. Each link provides access to a photograph of a core section which is accompanied by a description of the events or phenomena preserved in the sediment. Important discoveries preserved in these cores include the asteroid impact at the Cretaceous-Tertiary boundary, mineral-bearing hydrothermal deposits from the Mid-Atlantic Ridge, evidence of plate tectonics, and evidence of climate change.

398

Statewide General Education Core Program  

E-print Network

Statewide General Education Core Program #12;Project Timeline Date Activity Sept. 26 Faculty Senate Chemistry I · ESC X000 Intro to Earth Science · EVR X001 Intro to Environmental Science · PHY X020

Pilyugin, Sergei S.

399

Assessing Core Competencies  

NASA Astrophysics Data System (ADS)

Catherine Palomba and Trudy Banta offer the following definition of assessment, adapted from one provided by Marches in 1987. Assessment in the systematic collection, review, and use of information about educational programs undertaken for the purpose of improving student learning and development. (Palomba and Banta 1999). It is widely recognized that sophisticated computing technologies are becoming a key element in today's classroom instructional techniques. Regardless, the Professor must be held responsible for creating an instructional environment in which the technology actually supplements learning outcomes of the students. Almost all academic disciplines have found a niche for computer-based instruction in their respective professional domain. In many cases, it is viewed as an essential and integral part of the educational process. Educational institutions are committing substantial resources to the establishment of dedicated technology-based laboratories, so that they will be able to accommodate and fulfill students' desire to master certain of these specific skills. This type of technology-based instruction may raise some fundamental questions about the core competencies of the student learner. Some of the most important questions are : 1. Is the utilization of these fast high-powered computers and user-friendly software programs creating a totally non-challenging instructional environment for the student learner ? 2. Can technology itself all too easily overshadow the learning outcomes intended ? 3. Are the educational institutions simply training students how to use technology rather than educating them in the appropriate field ? 4. Are we still teaching content-driven courses and analysis oriented subject matter ? 5. Are these sophisticated modern era technologies contributing to a decline in the Critical Thinking Capabilities of the 21st century technology-savvy students ? The author tries to focus on technology as a tool and not on the technology itself. He further argues that students must demonstrate that they have the have the ability to think critically before they make an attempt to use technology in a chosen application-specific environment. The author further argues that training-based instruction has a very narrow focus that puts modern technology at the forefront of the learning enterprise system. The author promotes education-oriented strategies to provide the students with a broader perspective of the subject matter. The author is also of the opinion that students entering the workplace should clearly understand the context in which modern technologies are influencing the productive outcomes of the industrialized world. References : Marchese, T. J. (1987). Third Down, Ten Years to go. AAHE Bulletin, Vol. 40, pages 3-8. Marchese, T. J. (1994). Assessment, Quality and Undergraduate Improvement. Assessment Update, Vol. 6, No. 3. pages 1-14. Montagu, A. S. (2001). High-technology instruction: A framework for teaching computer-based technologies. Journal on Excellence in College Teaching, 12 (1), 109-128. Palomba, Catherine A. and Banta, Trudy W.(1999). Assessment Essentials :Planning, Implementing and Improving Assessment in Higher Education. San Francisco : Jossey Bass Publishers.

Narayanan, M.

2004-12-01

400

Summary of multi-core hardware and programming model investigations  

SciTech Connect

This report summarizes our investigations into multi-core processors and programming models for parallel scientific applications. The motivation for this study was to better understand the landscape of multi-core hardware, future trends, and the implications on system software for capability supercomputers. The results of this study are being used as input into the design of a new open-source light-weight kernel operating system being targeted at future capability supercomputers made up of multi-core processors. A goal of this effort is to create an agile system that is able to adapt to and efficiently support whatever multi-core hardware and programming models gain acceptance by the community.

Kelly, Suzanne Marie; Pedretti, Kevin Thomas Tauke; Levenhagen, Michael J.

2008-05-01

401

Thermal barrier and support for nuclear reactor fuel core  

DOEpatents

A thermal barrier/core support for the fuel core of a nuclear reactor having a metallic cylinder secured to the reactor vessel liner and surrounded by fibrous insulation material. A top cap is secured to the upper end of the metallic cylinder that locates and orients a cover block and post seat. Under normal operating conditions, the metallic cylinder supports the entire load exerted by its associated fuel core post. Disposed within the metallic cylinder is a column of ceramic material, the height of which is less than that of the metallic cylinder, and thus is not normally load bearing. In the event of a temperature excursion beyond the design limits of the metallic cylinder and resulting in deformation of the cylinder, the ceramic column will abut the top cap to support the fuel core post.

Betts, Jr., William S. (Del Mar, CA); Pickering, J. Larry (Del Mar, CA); Black, William E. (San Diego, CA)

1987-01-01

402

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Core or test hole cores, samples, cuttings. 3593.1 Section 3593.1...EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings. (a) The...

2013-10-01

403

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Core or test hole cores, samples, cuttings. 3593.1 Section 3593.1...EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings. (a) The...

2011-10-01

404

43 CFR 3593.1 - Core or test hole cores, samples, cuttings.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Core or test hole cores, samples, cuttings. 3593.1 Section 3593.1...EXPLORATION AND MINING OPERATIONS Bore Holes and Samples § 3593.1 Core or test hole cores, samples, cuttings. (a) The...

2012-10-01

405

Vapor core propulsion reactors  

NASA Technical Reports Server (NTRS)

Many research issues were addressed. For example, it became obvious that uranium tetrafluoride (UF4) is a most preferred fuel over uranium hexafluoride (UF6). UF4 has a very attractive vaporization point (1 atm at 1800 K). Materials compatible with UF4 were looked at, like tungsten, molybdenum, rhenium, carbon. It was found that in the molten state, UF4 and uranium attacked most everything, but in the vapor state they are not that bad. Compatible materials were identified for both the liquid and vapor states. A series of analyses were established to determine how the cavity should be designed. A series of experiments were performed to determine the properties of the fluid, including enhancement of the electrical conductivity of the system. CFD's and experimental programs are available that deal with most of the major issues.

Diaz, Nils J.

1991-01-01

406

Welding Technician National Core Curriculum  

NSDL National Science Digital Library

The National Center for Welding Education and Training (Weld-Ed) created this document to help educational institutions develop or review welding technician programs. This core curriculum provides a validated listing of the core of what students should know and be able to do after completing a welding technician program. Experts consulted in the creation of this curriculum included Weld-Ed regional centers and a validation panel of education and industry representatives from across the country.

2011-10-11

407

Common Core in Mathematics: Overview  

NSDL National Science Digital Library

This 13-minute video shows CCSS contributing author David Coleman discussing the background of the Common Core State Standards, their value in the state, the principles of their development, and the changes required of schools during this transition. The video details six important shifts in math instruction that will take place through the Common Core, these include: more focus, coherence, fluency, deeper understanding, flexible application, and dual intensity. Included with this video are resources for teachers and discussion questions.

Engageny

2011-01-01

408

Truth about motor core loss  

SciTech Connect

The phenomena of energy losses in electric motors known as core losses is discussed. Both hysteresis losses and eddy losses were included in the presentation. Factors affecting hysteresis losses include the chemical composition of the steel, the physical properties of the steel, the strength of the magnetic field, and the frequency of the applied voltage. The lamination of cores for the reduction of eddy losses is also mentioned.

Nailen, R.L.

1983-03-01

409

Lunar magnetism. [primordial core model  

NASA Technical Reports Server (NTRS)

It is shown, for a very simple model of the moon, that the existence of a primordial core magnetic field would give rise to a present day nonzero dipole external field. In the investigation a uniformly magnetized core embedded in a permeable mantle is considered. The significance of the obtained results for the conclusions reported by Runcorn (1975) is discussed. Comments provided by Runcorn to the discussion are also presented.

Goldstein, M. L.

1975-01-01

410

Comparing the Common Core State Standards in Mathematics to the Recommendations of the National Mathematics Advisory Panel. 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

411

Comparing the Common Core State Standards in Mathematics and Japan's Mathematics Curriculum in the Course of Study. Achieving the Common Core  

ERIC Educational Resources Information Center

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

412

Radial modulation doping in core-shell nanowires  

NASA Astrophysics Data System (ADS)

Semiconductor nanowires are potential candidates for applications in quantum information processing, Josephson junctions and field-effect transistors and provide a unique test bed for low-dimensional physical phenomena. The ability to fabricate nanowire heterostructures with atomically flat, defect-free interfaces enables energy band engineering in both axial and radial directions. The design of radial, or core-shell, nanowire heterostructures relies on energy band offsets that confine charge carriers into the core region, potentially reducing scattering from charged impurities on the nanowire surface. Key to the design of such nanoscale heterostructures is a fundamental understanding of the heterointerface properties, particularly energy band offsets and strain. The charge-transfer and confinement mechanism can be used to achieve modulation doping in core-shell structures. By selectively doping the shell, which has a larger bandgap, charge carriers are donated and confined in the core, generating a quasi-one-dimensional electron system with higher mobility. Here, we demonstrate radial modulation doping in coherently strained Ge-SixGe1-x core-shell nanowires and a technique to directly measure their valence band offset. Radial modulation doping is achieved by incorporating a B-doped layer during epitaxial shell growth. In contrast to previous work showing site-selective doping in Ge-Si core-shell nanowires, we find both an enhancement in peak hole mobility compared with undoped nanowires and observe a decoupling of electron transport in the core and shell regions. This decoupling stems from the higher carrier mobility in the core than in the shell and allows a direct measurement of the valence band offset for nanowires of various shell compositions.

Dillen, David C.; Kim, Kyounghwan; Liu, En-Shao; Tutuc, Emanuel

2014-02-01

413

Use of Thoria-Urania Fuels in PWRs: A General Review of a NERI Project to Assess Feasible Core Designs, Economics, Fabrication Methods, In-Pile Thermal/Mechanical Behavior, and Waste Form Characteristics  

SciTech Connect

This paper provides an introduction to and a summary of the remaining papers in this issue of Nuclear Technology. The papers in this issue present the important results from a U.S. Department of Energy-sponsored Nuclear Engineering Research Initiative (NERI) project to study the efficacy of the thorium-uranium dioxide (ThO{sub 2}-UO{sub 2}) once-through fuel cycle in current light water reactors. The project addressed fuel cycle neutronics and economics; ThO{sub 2}-UO{sub 2} fuel manufacturing; the in-pile thermal/mechanical behavior of ThO{sub 2}-UO{sub 2} fuel during normal, off-normal, and accident conditions; and the long-term stability of ThO{sub 2}-UO{sub 2} waste. Results from this work show that a small-scale separation of the uranium and thorium will enhance the fuel reactivity and achievable burnup from uranium-thorium dioxide fuels. Under conditions that meet the thermal requirements in present pressurized water reactors (PWRs), a properly designed microheterogeneous fuel will have more reactivity than all-uranium fuel, and the overall production of plutonium is significantly reduced. The use of thorium as a host for actinide fuels when PWRs are used for actinide transmutation was also explored. It was also determined that there were no fundamental obstacles to converting the current plants that manufacture uranium oxide-only fuel to a mixed ThO{sub 2}-UO{sub 2} fuel. Also, the in-service and transient thermal and mechanical performance of homogeneous ThO{sub 2}-UO{sub 2}-based fuels with respect to safety is generally equal to or better than that of all-uranium fuel. Furthermore, a mixed thorium-uranium dioxide spent fuel appears to be a much more stable waste form than uranium oxide spent fuel.

MacDonald, Philip E. [Idaho National Engineering and Environmental Laboratory (United States); Lee, Chan Bock [Korea Atomic Energy Research Institute (Korea, Republic of)

2004-07-15

414

Use of Thoria-Urania Fuels in PWRs - A General Review of a NERI Project to Assess Feasible Core Design, Economics, Fabrication Methods, In-Pile Thermal/Mechanical Behavior, and Waste Form Characteristics  

SciTech Connect

This paper provides an introduction to and a summary of the remaining papers in this issue of Nuclear Technology. The papers in this issue present the important results from a U.S. Department of Energy-sponsored Nuclear Engineering Research Initiative (NERI) project to study the efficacy of the thorium-uranium dioxide (ThO2-UO2) once-through fuel cycle in current light water reactors. The project addressed fuel cycle neutronics and economics; ThO2-UO2 fuel manufacturing; the in-pile thermal/mechanical behavior of ThO2-UO2 fuel during normal, off-normal, and accident conditions; and the long-term stability of ThO2-UO2 waste. Results from this work show that a small-scale separation of the uranium and thorium will enhance the fuel reactivity and achievable burnup from uranium-thorium dioxide fuels. Under conditions that meet the thermal requirements in present pressurized water reactors (PWRs), a properly designed microheterogeneous fuel will have more reactivity than all-uranium fuel, and the overall production of plutonium is significantly reduced. The use of thorium as a host for actinide fuels when PWRs are used for actinide transmutation was also explored. It was also determined that there were no fundamental obstacles to converting the current plants that manufacture uranium oxide-only fuel to a mixed ThO2-UO2 fuel. Also, the in-service and transient thermal and mechanical performance of homogeneous ThO2-UO2-based fuels with respect to safety is generally equal to or better than that of all-uranium fuel. Furthermore, a mixed thorium-uranium dioxide spent fuel appears to be a much more stable waste form than uranium oxide spent fuel.

P. E. MacDonald

2004-07-01

415

Design of the upper internals structure for the Clinch River Breeder Reactor Plant  

Microsoft Academic Search

The Upper Internals Structure (UIS) is located above the core and is supported from the head at four locations. It is designed to perform the following primary functions: provide secondary core holddown in the event of a malfunction of the core hydraulic holddown system; provide support for routing all in-vessel instrumentation to core assemblies; maintain alignment between the core assemblies,

D. C. Thompson; E. H. Novendstern

1977-01-01

416

Analysis of Resistive-Bridging Defects in SRAM Core-Cells: a Comparative Study from 90nm  

E-print Network

132 Analysis of Resistive-Bridging Defects in SRAM Core-Cells: a Comparative Study from 90nm down a comparative study on the effects of resistive-bridging defects in the SRAM core-cells, considering different technology nodes. In particular, we analyze industrial designs of SRAM core-cell at the following technology

Paris-Sud XI, Université de

417

Standard 4-Year Course Plan for BS Computer Science & Engineering under Core 2009 (For students beginning Fall 2012)  

E-print Network

­ Embedded Systems Junior Fall Winter Spring University Core University Core University Core Free Elective ­ Software Engineering COEN 175 ­ Compilers COEN 122 ­ Computer Architecture COEN 194 ­ Senior Design I (2 or the department's programming diagnostic exam, may replace COEN 10 with a free elective. Such students should take

Holliday, JoAnne

418

Full Core 3-D Simulation of a Partial MOX LWR Core  

SciTech Connect

A comparative analysis and comparison of results obtained between 2-D lattice calculations and 3-D full core nodal calculations, in the frame of MOX fuel design, was conducted. This study revealed a set of advantages and disadvantages, with respect to each method, which can be used to guide the level of accuracy desired for future fuel and fuel cycle calculations. For the purpose of isotopic generation for fuel cycle analyses, the approach of using a 2-D lattice code (i.e., fuel assembly in infinite lattice) gave reasonable predictions of uranium and plutonium isotope concentrations at the predicted 3-D core simulation batch average discharge burnup. However, it was found that the 2-D lattice calculation can under-predict the power of pins located along a shared edge between MOX and UO2 by as much as 20%. In this analysis, this error did not occur in the peak pin. However, this was a coincidence and does not rule out the possibility that the peak pin could occur in a lattice position with high calculation uncertainty in future un-optimized studies. Another important consideration in realistic fuel design is the prediction of the peak axial burnup and neutron fluence. The use of 3-D core simulation gave peak burnup conditions, at the pellet level, to be approximately 1.4 times greater than what can be predicted using back-of-the-envelope assumptions of average specific power and irradiation time.

S. Bays; W. Skerjanc; M. Pope

2009-05-01

419

Dynamic Cores in Hydrostatic Disguise  

NASA Astrophysics Data System (ADS)

We discuss the column density profiles of ``cores'' in three-dimensional smoothed particle hydrodynamics (SPH) numerical simulations of turbulent molecular clouds. The SPH scheme allows us to perform a high spatial resolution analysis of the density maxima (cores) at scales between ~0.003 and 0.3 pc. We analyze simulations in three different physical conditions: large-scale driving (LSD), small-scale driving (SSD), and random Gaussian initial conditions without driving (GC), each one at two different time steps: just before self-gravity is turned on (t0) and when gravity has been operating such that 5% of the total mass in the box has been accreted into cores (t1). For this data set, we perform Bonnor-Ebert fits to the column density profiles of cores found by a clump-finding algorithm. We find that, for the particular fitting procedure we use, 65% of the cores can be matched to Bonnor-Ebert (BE) profiles, and of these, 47% correspond to stable equilibrium configurations with ?max<6.5, even though the cores analyzed in the simulations are not in equilibrium but instead are dynamically evolving. The temperatures obtained with the fitting procedure vary between 5 and 60 K (in spite of the simulations being isothermal, with T=11.3 K), with the peak of the distribution being at T=11 K and most clumps having fitted temperatures between 5 and 30 K. Central densities obtained with the BE fit tend to be smaller than the actual central densities of the cores. We also find that for the LSD and GC cases, there are more BE-like cores at t0 than at t1 with ?max<=20, while in the case of SSD, there are more such cores at t1 than at t0. We interpret this as a consequence of the stronger turbulence present in the cores of run SSD, which prevents good BE fits in the absence of gravity, and delays collapse in its presence. Finally, in some cases we find substantial superposition effects when we analyze the projection of the density structures, even though the scales over which we project are small (<~0.18 pc). As a consequence, different projections of the same core may give very different values of the BE fits. Finally, we briefly discuss recent results claiming that Bok globule B68 is in hydrostatic equilibrium, stressing that they imply that this core is unstable by a wide margin. We conclude that fitting BE profiles to observed cores is not an unambiguous test of hydrostatic equilibrium and that fit-estimated parameters such as mass, central density, density contrast, temperature, or radial profile of the BE sphere may differ significantly from the actual values in the cores.

Ballesteros-Paredes, Javier; Klessen, Ralf S.; Vázquez-Semadeni, Enrique

2003-07-01

420

Study on Ultra-Long Life,Small U-Zr Metallic Fuelled Core With Burnable Poison  

SciTech Connect

A conceptual design for a 50 MWe sodium cooled, U-Pu-Zr metallic fuelled, fast reactor core, which aims at a core lifetime of 30 years, has been performed [1]. As for the compensation for a large burn-up reactivity through 30 years, an axially movable reflector, which is located around the core, carries the major part of it and a burnable poison does the rest. This concept has achieved not only a long core lifetime but also a high discharged burn-up. On this study, a conceptual design for a small fast reactor loading U-Zr metallic fuelled core instead of U-Pu-Zr fuelled core has been conducted, based on the original core arrangement of 4S reactor [2]. Within the range of this study including safety requirements, adopting the burnable poison would be effective to construct a core concept that achieves both a long lifetime and a high discharged burn-up. (authors)

Kenji Tsuji; Hiromitsu Inagaki; Akira Nishikawa [Chubu Electric Power Company Inc., 1, Higashi-shincho Higashi-ku, Nagoya-shi, ACH 461-8680 (Japan); Hisato Matsumiya; Yoshiaki Sakashita; Yasuyuki Moriki; Mitsuaki Yamaoka; Norihiko Handa [Toshiba Corporation (Japan)

2002-07-01

421

Core formation in silicate bodies  

NASA Astrophysics Data System (ADS)

Differentiation of a body into a metallic core and silicate mantle occurs most efficiently if temperatures are high enough to allow at least the metal to melt [1], and is enhanced if matrix deformation occurs [2]. Elevated temperatures may occur due to either decay of short-lived radio-isotopes, or gravitational energy release during accretion [3]. For bodies smaller than the Moon, core formation happens primarily due to radioactive decay. The Hf-W isotopic system may be used to date core formation; cores in some iron meteorites and the eucrite parent body (probably Vesta) formed within 1 My and 1-4~My of solar system formation, respectively [4]. These formation times are early enough to ensure widespread melting and differentiation by 26Al decay. Incorporation of Fe60 into the core, together with rapid early mantle solidification and cooling, may have driven early dynamo activity on some bodies [5]. Iron meteorites are typically depleted in sulphur relative to chondrites, for unknown reasons [6]. This depletion contrasts with the apparently higher sulphur contents of cores in larger planetary bodies, such as Mars [7], and also has a significant effect on the timing of core solidification. For bodies of Moon-size and larger, gravitational energy released during accretion is probably the primary cause of core formation [3]. The final stages of accretion involve large, stochastic collisions [8] between objects which are already differentiated. During each collision, the metallic cores of the colliding objects merge on timescales of a few hours [9]. Each collision will reset the Hf-W isotopic signature of both mantle and core, depending on the degree to which the impactor core re-equilibrates with the mantle of the target [10]. The re-equilibration efficiency depends mainly on the degree to which the impactor emulsifies [11], which is very uncertain. Results from N-body simulations [8,12] suggest that significant degrees of re- equilibration are required [4,10]. Re-equilibration is also suggested by mantle siderophile abundances [13], though simple partitioning models do not capture the likely complex P,T evolution during successive giant impacts. The timescale of Martian core formation is currently uncertain (0-10 My) [14], though it is clear that Martian core formation ended before that of the Earth. [1] Stevenson, in Origin of the Earth, 1990. [2] Groebner and Kohlstedt, EPSL 2006. [3] Rubie et al., Treatise Geophys. 2007. [4] Kleine et al., GCA submitted. [5] Weiss et al., LPSC 39, 2008. [6] Keil and Wilson, EPSL 1993 [7] Wanke and Dreibus, PTRSL, 1984. [8] Agnor et al. Icarus 1999 [9] Canup and Asphaug, Nature 2001 [10] Nimmo and Agnor, EPSL 2006. [11] Rubie et al., EPSL 2003 [12] O'Brien et al, Icarus 2006 [13] Righter, AREPS 2003. [14] Nimmo and Kleine, Icarus 2007.

Nimmo, F.; O'Brien, D. P.; Kleine, T.

2008-12-01

422

Impact Vaporization of Planetesimal Cores  

NASA Astrophysics Data System (ADS)

The degree of mixing and chemical equilibration between the iron cores of planetesimals and the mantle of the growing Earth has important consequences for understanding the end stages of Earth's formation and planet formation in general. At the Sandia Z machine, we developed a new shock-and-release technique to determine the density on the liquid-vapor dome of iron, the entropy on the iron shock Hugoniot, and the criteria for shock-induced vaporization of iron. We find that the critical shock pressure to vaporize iron is 507(+65,-85) GPa and show that decompression from a 15 km/s impact will initiate vaporization of iron cores, which is a velocity that is readily achieved at the end stages of planet formation. Vaporization of the iron cores increases dispersal of planetesimal cores, enables more complete chemical equilibration of the planetesimal cores with Earth's mantle, and reduces the highly siderophile element abundance on the Moon relative to Earth due to the expanding iron vapor exceeding the Moon's escape velocity. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Securities Administration under Contract No. DE-AC04-94AL85000.

Kraus, R. G.; Root, S.; Lemke, R. W.; Stewart, S. T.; Jacobsen, S. B.; Mattsson, T. R.

2013-12-01

423

Towards a core calculus for implicitly migration-capable applications  

E-print Network

DRAFT Towards a core calculus for implicitly migration-capable applications Michael Greenberg mobile ones. Therefore, the ability to migrate UI- enabled applications is becoming increasingly important. We de- scribe a design-pattern for applications to simplify support for user- session migration

Plotkin, Joshua B.

424

Core exploration in optimization of chemokine receptor CCR4 antagonists.  

PubMed

The design, synthesis, and SAR studies of 'core' variations led to identification of novel, selective, and potent small molecule antagonist (22) of the CC chemokine receptor-4 (CCR4) with improved in vitro activity and liability profile. Compound 22 was efficacious in a murine allergic inflammation model (ED50 approximately 10 mg/kg). PMID:17098428

Purandare, Ashok V; Wan, Honghe; Somerville, John E; Burke, Christine; Vaccaro, Wayne; Yang, XiaoXia; McIntyre, Kim W; Poss, Michael A

2007-02-01

425

The Unified Core: A "Major" Learning Community Model in Action  

ERIC Educational Resources Information Center

The Unified Core is an innovative approach to higher education that blends content through linked courses within a major to create a community of learners. This article offers the theoretical background for the approach, describes the implementation, and offers suggestions to educators who would like to design their own version of this innovative…

Powell, Gwynn M.; Johnson, Corey W.; James, J. Joy; Dunlap, Rudy

2011-01-01

426

Thermal hydraulic analysis of the FFTF core usng SUPERENERGY-2  

Microsoft Academic Search

The temperature distribution for essentially the whole FFTF core for every cycle of operation is needed. This involves a very large amount of data for both input and output. SUPERENERGY was designed specifically to meet these operational needs. The simplified energy equation mixing model used by SUPERENERGY is well established and extremely economical in both computer storage and run time.

1981-01-01

427

Analysis of the Gas Core Actinide Transmutation Reactor (GCATR)  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

428

MIT Lincoln Laboratory CORE Confronting Obstacles & Realizing Excellence  

E-print Network

of 8th grade MCAS score Student Essay (no longer than 1 page) Passport sized photograph. Picture needs to maintain a need-blind admissions policy; however, some scholarship funds are designated for students whoMIT Lincoln Laboratory CORE Confronting Obstacles & Realizing Excellence Student Application 2014

Reuter, Martin

429

Kansas Vocational Agriculture Education. Basic Core Curriculum Project, Horticulture I.  

ERIC Educational Resources Information Center

This secondary horticulture curriculum guide is one of a set of three designated as the basic core of instruction for horticulture programs in Kansas. Units of instruction are presented in thirteen sections: (1) Orientation and Careers, (2) Leadership and Future Farmers of America, (3) Supervised Occupational Experience Program, (4) Plant…

Albracht, James, Ed.

430

Engineering Advising Aid 2014-16 Core Curriculum Requirements  

E-print Network

hours) African & African Diaspora Studies AFR 311C AFR 356C AFR 356D AFR 356E American Studies AMS C C 303 C C 307C C C 307D Core Texts & Ideas CTI 350 CTI 351 Design DES 308 English E 321P 1 & Behavioral Sciences: (3 hours) African & African Diaspora Studies AFR 324E Anthropology ANT 302 ANT 305

Ben-Yakar, Adela

431

Soft-core processor study for node-based architectures  

Microsoft Academic Search

Node-based architecture (NBA) designs for future satellite projects hold the promise of decreasing system development time and costs, size, weight, and power and positioning the laboratory to address other emerging mission opportunities quickly. Reconfigurable Field Programmable Gate Array (FPGA) based modules will comprise the core of several of the NBA nodes. Microprocessing capabilities will be necessary with varying degrees of

Jonathan Roger Van Houten; Jason P. Jarosz; Benjamin James Welch; Daniel E. Gallegos; Mark Walter Learn

2008-01-01

432

HTGR analytical methods and design verification  

SciTech Connect

Analytical methods for the high-temperature gas-cooled reactor (HTGR) include development, update, verification, documentation, and maintenance of all computer codes for HTGR design and analysis. This paper presents selected nuclear, structural mechanics, seismic, and systems analytical methods related to the HTGR core. This paper also reviews design verification tests in the reactor core, reactor internals, steam generator, and thermal barrier.

Neylan, A.J.; Northup, T.E.

1982-05-01

433

A 45nm 8-core enterprise Xeon® processor  

Microsoft Academic Search

The next-generation enterprise Xeonreg server processor consists of eight dual- threaded 64b Nehalem cores and a shared L3 cache. The system interface includes two on-chip memory controllers and supports multiple system topologies. This design has 2.3B transistors and is implemented in 45 nm CMOS using metal-gate high-K dielectric transistors and nine Cu interconnect layers. The thermal design power is 130

S. Rusu; S. Tam; H. Muljono; J. Stinson; D. Ayers; J. Chang; R. Varada; M. Ratta; S. Kottapalli

2009-01-01

434

Ring-core fluxgate magnetometers for use as observatory variometers  

Microsoft Academic Search

Ring-core magnetometers, based on the published design for the MAGSAT fluxgate magnetometer, are or will soon be in use in observatories in the U.S.A. and in Canada. Their low noise level and good stability with both temperature and time make them well suited for this purpose. We describe the critical performance features and design aspects for these instruments. Noise in

B. B. Narod; J. R. Bennest

1990-01-01

435

Ultrahigh temperature vapor core reactor-MHD system for space nuclear electric power  

NASA Technical Reports Server (NTRS)

The conceptual design of a nuclear space power system based on the ultrahigh temperature vapor core reactor with MHD energy conversion is presented. This UF4 fueled gas core cavity reactor operates at 4000 K maximum core temperature and 40 atm. Materials experiments, conducted with UF4 up to 2200 K, demonstrate acceptable compatibility with tungsten-molybdenum-, and carbon-based materials. The supporting nuclear, heat transfer, fluid flow and MHD analysis, and fissioning plasma physics experiments are also discussed.

Maya, Isaac; Anghaie, Samim; Diaz, Nils J.; Dugan, Edward T.

1991-01-01

436

Amphiphilic polymeric particles with core–shell nanostructures: emulsion-based syntheses and potential applications  

Microsoft Academic Search

The design and synthesis of amphiphilic nano- to micro-sized polymeric particles with core–shell nanostructures have attracted\\u000a more and more attention because of their wide applicability in modern material science and their technological importance\\u000a in the areas of colloid and interface science. Many synthetic strategies have been developed for the preparation of amphiphilic\\u000a core–shell particles that consist of hydrophobic polymer cores

Kin Man Ho; Wei Ying Li; Chun Him Wong; Pei Li

2010-01-01

437

Multiple defect-core hexagonal photonic crystal fiber with flattened dispersion and polarization maintaining properties  

Microsoft Academic Search

In this paper, we present a dispersion controlling technique with a multiple defect-core hexagonal photonic crystal fiber\\u000a (MD-HPCF). By omitting air holes in the core region of the conventional HPCF and adjusting the size of air holes around the\\u000a newly formed core, we can successfully design low flattened dispersion PCF with low confinement loss, as well as high birefringence.\\u000a The

Shubi F. Kaijage; Yoshinori Namihira; Nguyen H. Hai; Feroza Begum; S. M. Abdur Razzak; Tatsuya Kinjo; Hiroki Higa; Nianyu Zou

2008-01-01

438

Ice Core Paleoclimatology Research Group  

NSDL National Science Digital Library

This site, hosted by Ohio State University, contributes to our understanding of the complex interactions within the Earth's coupled climate system through the collection and study of a global array of ice cores. These acquisitions provides high resolution climatic and environmental histories that will include ice core histories from Africa, Antarctica, Bolivia, China, Greenland, Peru, Russia and the United States. The project makes it possible to study processes linking the Polar Regions to the lower latitudes where human activities are most intense. These ice core records contribute prominently to the Earth's paleoclimate record, the ultimate yardstick against which the significance of present and projected anthropogenic effects will be assessed. Images, data sets, publications and research projects are linked to the home page.

Center, Byrd P.; University, Ohio S.

439

Reactor core isolation cooling system  

DOEpatents

A reactor core isolation cooling system includes a reactor pressure vessel containing a reactor core, a drywell vessel, a containment vessel, and an isolation pool containing an isolation condenser. A turbine is operatively joined to the pressure vessel outlet steamline and powers a pump operatively joined to the pressure vessel feedwater line. In operation, steam from the pressure vessel powers the turbine which in turn powers the pump to pump makeup water from a pool to the feedwater line into the pressure vessel for maintaining water level over the reactor core. Steam discharged from the turbine is channeled to the isolation condenser and is condensed therein. The resulting heat is discharged into the isolation pool and vented to the atmosphere outside the containment vessel for removing heat therefrom. 1 figure.

Cooke, F.E.

1992-12-08

440

Time delays between core power production and external detector response from Monte Carlo calculations  

SciTech Connect

One primary concern for design of safety systems for reactors is the time response of external detectors to changes in the core. This paper describes a way to estimate the time delay between the core power production and the external detector response using Monte Carlo calculations and suggests a technique to measure the time delay. The Monte Carlo code KENO-NR was used to determine the time delay between the core power production and the external detector response for a conceptual design of the Advanced Neutron Source (ANS) reactor. The Monte Carlo estimated time delay was determined to be about 10 ms for this conceptual design of the ANS reactor.

Valentine, T.E.; Mihalczo, J.T.

1996-08-01

441

Initial Results From the new Long Coring System of RV Knorr  

NASA Astrophysics Data System (ADS)

A new long piston coring system has been designed and built for RV Knorr. The system is capable of deploying core lengths up to 46 m and weights of ~25000 lbs. With suitable modifications to other ships, a slightly smaller system could be deployed from other large UNOLS vessels. The handling system was designed around a hybrid rope blend of Vectran and Plasma braided with a torque-balanced, non- rotating construction. The rope is 7500 m long with a breaking strength (~360,000 lbs) more than 10 times greater than the pullout tensions experienced by the coring system. The high breaking strength limits stretching during coring operations, which minimizes rebound of the rope and movement of the piston during core penetration. An accelerometer placed on the release system documented that rope rebound was less than 2 m after the release of a ~15000 lb core at a water depth of 4585 m. The handling system for the new core includes a new A-frame mounted with a load transfer winch and a vertically-mounted rigging boom; a new stern-mounted grapple for transferring the corer from starboard to stern; a new deck-mounted traction winch for the Vectran-Plasma rope; and three new computer-controlled davit cranes along the starboard rail to raise and lower the corer between horizontal and vertical orientations. During testing at Bermuda Rise, core recovery exceeded 38 m, with cores generally filling 85% to 90% of the piston core barrel length. The test location has been cored