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1

Piping benchmark problems for the Westinghouse AP600 Standardized Plant  

SciTech Connect

To satisfy the need for verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for the Westinghouse AP600 Standardized Plant, three benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the AP600 standard design. It will be required that the combined license licensees demonstrate that their solutions to these problems are in agreement with the benchmark problem set.

Bezler, P.; DeGrassi, G.; Braverman, J.; Wang, Y.K.

1997-01-01

2

Piping benchmark problems for the ABB/CE System 80+ Standardized Plant  

SciTech Connect

To satisfy the need for verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for the ABB/Combustion Engineering System 80+ Standardized Plant, three benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the System 80+ standard design. It will be required that the combined license licensees demonstrate that their solution to these problems are in agreement with the benchmark problem set. The first System 80+ piping benchmark is a uniform support motion response spectrum solution for one section of the feedwater piping subjected to safe shutdown seismic loads. The second System 80+ piping benchmark is a time history solution for the feedwater piping subjected to the transient loading induced by a water hammer. The third System 80+ piping benchmark is a time history solution of the pressurizer surge line subjected to the accelerations induced by a main steam line pipe break. The System 80+ reactor is an advanced PWR type.

Bezler, P.; DeGrassi, G.; Braverman, J.; Wang, Y.K. [Brookhaven National Lab., Upton, NY (United States)] [Brookhaven National Lab., Upton, NY (United States)

1994-07-01

3

Piping benchmark problems. Volume 1. Dynamic analysis uniform support motion response spectrum method  

SciTech Connect

A set of benchmark problems and solutions have been developed for verifying the adequacy of computer programs used for dynamic analysis and design of nuclear piping systems by the Response Spectrum Method. The problems range from simple to complex configurations which are assumed to experience linear elastic behavior. The dynamic loading is represented by uniform support motion, assumed to be induced by seismic excitation in three spatial directions. The solutions consist of frequencies, participation factors, nodal displacement components and internal force and moment components. Solutions to associated anchor point motion static problems are not included.

Bezler, P.; Hartzman, M.; Reich, M.

1980-08-01

4

MCNP: Neutron benchmark problems  

SciTech Connect

The recent widespread and increased use of radiation transport codes has produced greater user and institutional demand for assurances that such codes give correct results. Responding to these requirements for code validation, the general purpose Monte Carlo transport code MCNP has been tested on criticality, pulsed sphere, and shielding neutron problem families. Results for each were compared to experimental data. MCNP successfully predicted the experimental results of all three families within the expected data and statistical uncertainties. These successful predictions demonstrate that MCNP can successfully model a broad spectrum of neutron transport problems. 18 refs., 27 figs., 4 tabs.

Whalen, D.J.; Cardon, D.A.; Uhle, J.L.; Hendricks, J.S.

1991-11-01

5

MCNP: Photon benchmark problems  

SciTech Connect

The recent widespread, markedly increased use of radiation transport codes has produced greater user and institutional demand for assurance that such codes give correct results. Responding to these pressing requirements for code validation, the general purpose Monte Carlo transport code MCNP has been tested on six different photon problem families. MCNP was used to simulate these six sets numerically. Results for each were compared to the set's analytical or experimental data. MCNP successfully predicted the analytical or experimental results of all six families within the statistical uncertainty inherent in the Monte Carlo method. From this we conclude that MCNP can accurately model a broad spectrum of photon transport problems. 8 refs., 30 figs., 5 tabs.

Whalen, D.J.; Hollowell, D.E.; Hendricks, J.S.

1991-09-01

6

Brief Announcement: The Problem Based Benchmark Suite  

E-print Network

). PBBS is a set of benchmarks designed for comparing par- allel algorithmic approaches, parallel [Analysis of Algorithms and Problem Complexity]: General Keywords: Parallel Algorithms, BenchmarkingBrief Announcement: The Problem Based Benchmark Suite Julian Shun Guy E. Blelloch Jeremy T. Fineman

7

Calculator solves pipe flow problems  

Microsoft Academic Search

For facilitating pipe-flow calculations that involve the horizontal flow of constant-density fluids, a simple program tailored to the TI-59 hand-held calculator uses the Darcy pressure-drop formula (modified for expressing the friction factor) to compute the unknown parameter needed to solve the fluid problem. Instead of several friction-factor equations applicable only in the individual flow regimes, the program uses a single,

1980-01-01

8

Calculator solves pipe flow problems  

SciTech Connect

For facilitating pipe-flow calculations that involve the horizontal flow of constant-density fluids, a simple program tailored to the TI-59 hand-held calculator uses the Darcy pressure-drop formula (modified for expressing the friction factor) to compute the unknown parameter needed to solve the fluid problem. Instead of several friction-factor equations applicable only in the individual flow regimes, the program uses a single, full-range friction-factor equation with three sets of coefficients to suit the conditions of the problem.

Verma, C.P.

1980-07-28

9

Modeling the 2008 Ultrasonic Benchmark Problems  

NASA Astrophysics Data System (ADS)

Two studies were part of the 2008 QNDE ultrasonic benchmark session. The first study considered the effects of the curvature of a fluid-solid interface on the pulse-echo immersion response of a flat-bottom hole. This was a re-examination of a problem considered in the 2007 benchmark but with a well-characterized transducer and a different set of testing conditions. The second study considered the response of a series of side-drilled holes at different depths. Here we will summarize the results obtained at the Center for NDE (CNDE), Iowa State University, for these two benchmark problems.

Schmerr, Lester W.; Huang, Ruiju

2009-03-01

10

Benchmark Problems for Spacecraft Formation Flying Missions  

NASA Technical Reports Server (NTRS)

To provide high-level focus to distributed space system flight dynamics and control research, several benchmark problems are suggested. These problems are not specific to any current or proposed mission, but instead are intended to capture high-level features that would be generic to many similar missions.

Carpenter, J. Russell; Leitner, Jesse A.; Burns, Richard D.; Folta, David C.

2003-01-01

11

Analysis of ANS LWR physics benchmark problems.  

SciTech Connect

Various Monte Carlo and deterministic solutions to the three PWR Lattice Benchmark Problems recently defined by the ANS Ad Hoc Committee on Reactor Physics Benchmarks are presented. These solutions were obtained using the VIM continuous-energy Monte Carlo code and the DIF3D/WIMS-D4M code package implemented at the Argonne National Laboratory. The code results for the K{sub eff} and relative pin power distribution are compared to measured values. Additionally, code results for the three benchmark-prescribed infinite lattice configurations are also intercompared. The results demonstrate that the codes produce very good estimates of both the K{sub eff} and power distribution for the critical core and the lattice parameters of the infinite lattice configuration.

Taiwo, T. A.

1998-07-29

12

A Set of Neural Network Benchmark Problems and Benchmarking Rules  

Microsoft Academic Search

Proben1 is a collection of problems for neural network learning in the realm of pattern classificationand function approximation plus a set of rules and conventions for carrying out benchmarktests with these or similar problems. Proben1 contains 15 data sets from 12 different domains. Alldatasets represent realistic problems which could be called diagnosis tasks and all but one consist ofreal world

Fakultat Fur Informatik; Lutz Prechelt

1994-01-01

13

Benchmark problems and results for verifying resonance calculation methodologies  

SciTech Connect

Resonance calculation is one of the most important procedures for the multi-group neutron transport calculation. With the development of nuclear reactor concepts, many new types of fuel assembly are raised. Compared to the traditional designs, most of the new fuel assemblies have different fuel types either with complex isotopes or with complicated geometry. This makes the traditional resonance calculation method invalid. Recently, many advanced resonance calculation methods are proposed. However, there are few benchmark problems for evaluating those methods with a comprehensive comparison. In this paper, we design 5 groups of benchmark problems including 21 typical cases of different geometries and fuel contents. The reference results of the benchmark problems are generated based on the sub-group method, ultra-fine group method, function expanding method and Monte Carlo method. It is shown that those benchmark problems and their results could be helpful to evaluate the validity of the newly developed resonance calculation method in the future work. (authors)

Wu, H.; Yang, W.; Qin, Y.; He, L.; Cao, L.; Zheng, Y.; Liu, Q. [NECP Laboratory, School of Nuclear Science and Technology, Xi'An Jiaotong Univ., 710049 (China)

2012-07-01

14

Simulation of the 2008 Ultrasonic Benchmark Problems Using UTDefect  

NASA Astrophysics Data System (ADS)

The computer program UTDefect is used to solve some of the 2008 ultrasonic benchmark problems. UTDefect is a program for simulation of ultrasonic testing with applications within the nuclear industry in mind. Scattering from various types of defects, like a side-drilled hole and a flat-bottom hole, is modelled using solutions that are essentially exact. For the benchmark problems the results obtained from UTDefect are in fairly good agreement with the experimental data from CEA.

Jansson, Per-Åke; Boström, Anders

2009-03-01

15

Simplified two and three dimensional HTTR benchmark problems  

SciTech Connect

To assess the accuracy of diffusion or transport methods for reactor calculations, it is desirable to create heterogeneous benchmark problems that are typical of whole core configurations. In this paper we have created two and three dimensional numerical benchmark problems typical of high temperature gas cooled prismatic cores. Additionally, a single cell and single block benchmark problems are also included. These problems were derived from the HTTR start-up experiment. Since the primary utility of the benchmark problems is in code-to-code verification, minor details regarding geometry and material specification of the original experiment have been simplified while retaining the heterogeneity and the major physics properties of the core from a neutronics viewpoint. A six-group material (macroscopic) cross section library has been generated for the benchmark problems using the lattice depletion code HELIOS. Using this library, Monte Carlo solutions are presented for three configurations (all-rods-in, partially-controlled and all-rods-out) for both the 2D and 3D problems. These solutions include the core eigenvalues, the block (assembly) averaged fission densities, local peaking factors, the absorption densities in the burnable poison and control rods, and pin fission density distribution for selected blocks. Also included are the solutions for the single cell and single block problems.

Zhan Zhang; Dingkang Zhang; Justin M. Pounders; Abderrafi M. Ougouag

2011-05-01

16

MFL Benchmark Problem 2: Laboratory Measurements  

NASA Astrophysics Data System (ADS)

This experiment involves the measurement of the magnetic flux leaked from a rotating seamless steel tube with two machined notches. The signal measured is the radial component of the leaked field at a fixed point in space, as a function of the notch position, for four values of the liftoff and two notches. As the pipe tangential velocity was varied between 0.23 and 0.62 m/s, the sole observed effect was that of increasing the signal by a value that grows linearly with the velocity and is independent of the notch angular position.

Etcheverry, J.; Pignotti, A.; Sánchez, G.; Stickar, P.

2003-03-01

17

A proposed benchmark problem for cargo nuclear threat monitoring  

NASA Astrophysics Data System (ADS)

There is currently a great deal of technical and political effort focused on reducing the risk of potential attacks on the United States involving radiological dispersal devices or nuclear weapons. This paper proposes a benchmark problem for gamma-ray and X-ray cargo monitoring with results calculated using MCNP5, v1.51. The primary goal is to provide a benchmark problem that will allow researchers in this area to evaluate Monte Carlo models for both speed and accuracy in both forward and inverse calculational codes and approaches for nuclear security applications. A previous benchmark problem was developed by one of the authors (RPG) for two similar oil well logging problems (Gardner and Verghese, 1991, [1]). One of those benchmarks has recently been used by at least two researchers in the nuclear threat area to evaluate the speed and accuracy of Monte Carlo codes combined with variance reduction techniques. This apparent need has prompted us to design this benchmark problem specifically for the nuclear threat researcher. This benchmark consists of conceptual design and preliminary calculational results using gamma-ray interactions on a system containing three thicknesses of three different shielding materials. A point source is placed inside the three materials lead, aluminum, and plywood. The first two materials are in right circular cylindrical form while the third is a cube. The entire system rests on a sufficiently thick lead base so as to reduce undesired scattering events. The configuration was arranged in such a manner that as gamma-ray moves from the source outward it first passes through the lead circular cylinder, then the aluminum circular cylinder, and finally the wooden cube before reaching the detector. A 2 in.×4 in.×16 in. box style NaI (Tl) detector was placed 1 m from the point source located in the center with the 4 in.×16 in. side facing the system. The two sources used in the benchmark are 137Cs and 235U.

Wesley Holmes, Thomas; Calderon, Adan; Peeples, Cody R.; Gardner, Robin P.

2011-10-01

18

Second Computational Aeroacoustics (CAA) Workshop on Benchmark Problems  

NASA Technical Reports Server (NTRS)

The proceedings of the Second Computational Aeroacoustics (CAA) Workshop on Benchmark Problems held at Florida State University are the subject of this report. For this workshop, problems arising in typical industrial applications of CAA were chosen. Comparisons between numerical solutions and exact solutions are presented where possible.

Tam, C. K. W. (Editor); Hardin, J. C. (Editor)

1997-01-01

19

The Traveling Tournament Problem Description and Benchmarks  

Microsoft Academic Search

The Traveling Tournament Problem is a sports timetablingproblem that abstracts the important issues in creating timetables whereteam travel is an important issue. Instances of this problem seem tobe very dicult to solve even for very small cases. Given the practicalimportance of solving instances similar to these, this makes this probleman interesting challenge for combinatorial optimization techniques. Weintroduce this problem, give

Kelly Easton; George L. Nemhauser; Michael A. Trick

2001-01-01

20

Third Computational Aeroacoustics (CAA) Workshop on Benchmark Problems  

NASA Technical Reports Server (NTRS)

The proceedings of the Third Computational Aeroacoustics (CAA) Workshop on Benchmark Problems cosponsored by the Ohio Aerospace Institute and the NASA Glenn Research Center are the subject of this report. Fan noise was the chosen theme for this workshop with representative problems encompassing four of the six benchmark problem categories. The other two categories were related to jet noise and cavity noise. For the first time in this series of workshops, the computational results for the cavity noise problem were compared to experimental data. All the other problems had exact solutions, which are included in this report. The Workshop included a panel discussion by representatives of industry. The participants gave their views on the status of applying computational aeroacoustics to solve practical industry related problems and what issues need to be addressed to make CAA a robust design tool.

Dahl, Milo D. (Editor)

2000-01-01

21

Validation of NESTLE against static reactor benchmark problems  

SciTech Connect

The NESTLE advanced modal code was developed at North Carolina State University with support from Los Alamos National Laboratory and Idaho National Engineering Laboratory. It recently has been benchmarked successfully against measured data from pressurized water reactors (PWRs). However, NESTLE`s geometric capabilities are very flexible, and it can be applied to a variety of other types of reactors. This study presents comparisons of NESTLE results with those from other codes for static benchmark problems for PWRs, boiling water reactors (BWRs), high-temperature gas-cooled reactors (HTGRs) and CANDU heavy- water reactors (HWRs).

Mosteller, R.D.

1996-02-01

22

Benchmark problems in which equality plays the major role  

SciTech Connect

We have recently heard rumors that researchers are again studying paramodulation (Wos87) in the context of strategy for its control. In part to facilitate such research, and in part to provide test problems for evaluating other approaches to equality-oriented reasoning, we offer in this article a set of benchmark problems in which equality plays the dominant role. The test problems are taken from group theory, Robbins algebra, combinatory logic, and other areas. For each problem, we include appropriate clauses and comment as to its status with regard to provability by an unaided automated reasoning program.

Lusk, E.; Wos, L.

1992-01-01

23

Benchmark problems in which equality plays the major role  

SciTech Connect

We have recently heard rumors that researchers are again studying paramodulation [Wos87] in the context of strategy for its control. In part to facilitate such research, and in part to provide test problems for evaluating other approaches to equality-oriented reasoning, we offer in this article a set of benchmark problems in which equality plays the dominant role. The test problems are taken from group theory, Robbins algebra, combinatory logic, and other areas. For each problem, we include appropriate clauses and comment as to its status with regard to provability by an unaided automated reasoning program.

Lusk, E.; Wos, L.

1992-05-01

24

Model Predictions to the 2005 Ultrasonic Benchmark Problems  

NASA Astrophysics Data System (ADS)

The World Federation of NDE Centers (WFNDEC) has addressed the 2005 ultrasonic benchmark problems including linear scanning of the side drilled hole (SDH) specimen with oblique incidence with an emphasis on further study on SV-wave responses of the SDH versus angles around 60 degrees and responses of a circular crack. To solve these problems, we adopted the multi-Gaussian beam model as beam models and the Kirchhoff approximation and the separation of variables method as far-field scattering models. By integration of the beam and scattering models and the system efficiency factor obtained from the given reference experimental setups provided by Center for Nondestructive Evaluation into our ultrasonic measurement models, we predicted the responses of the SDH and the circular cracks (pill-box crack like flaws). This paper summarizes our models and predicted results for the 2005 ultrasonic benchmark problems.

Kim, Hak-Joon; Song, Sung-Jin; Park, Joon-Soo

2006-03-01

25

Model Prediction Results for 2008 Ultrasonic Benchmark Problems  

NASA Astrophysics Data System (ADS)

The World Federation of NDE Centers (WFNDEC) has addressed two types of problems for the 2008 ultrasonic benchmark problems: effects of surface curvatures on the ultrasonic responses of flat-bottomed holes, and prediction of side-drilled hole responses at various depths in a steel block. To solve this year ultrasonic benchmark problems, multi-Gaussian beam models was adopted for calculation of insonifying fields on the flat-bottomed holes and the side-drilled holes. And, the Kirchhoff approximation and the separation of variables method were applied for calculation of far-field scattering amplitudes of flat-bottomed holes and side-drilled holes, respectively. In this paper, we present comparison of the model predictions to the experiments for side-drilled holes and discuss the effect of interface curvatures on ultrasonic responses by comparison of the peak-to-peak amplitudes of the flat-bottomed hole responses with different interface curvatures.

Kim, Hak-Joon; Song, Sung-Jin

2009-03-01

26

Fourth Computational Aeroacoustics (CAA) Workshop on Benchmark Problems  

NASA Technical Reports Server (NTRS)

This publication contains the proceedings of the Fourth Computational Aeroacoustics (CAA) Workshop on Benchmark Problems. In this workshop, as in previous workshops, the problems were devised to gauge the technological advancement of computational techniques to calculate all aspects of sound generation and propagation in air directly from the fundamental governing equations. A variety of benchmark problems have been previously solved ranging from simple geometries with idealized acoustic conditions to test the accuracy and effectiveness of computational algorithms and numerical boundary conditions; to sound radiation from a duct; to gust interaction with a cascade of airfoils; to the sound generated by a separating, turbulent viscous flow. By solving these and similar problems, workshop participants have shown the technical progress from the basic challenges to accurate CAA calculations to the solution of CAA problems of increasing complexity and difficulty. The fourth CAA workshop emphasized the application of CAA methods to the solution of realistic problems. The workshop was held at the Ohio Aerospace Institute in Cleveland, Ohio, on October 20 to 22, 2003. At that time, workshop participants presented their solutions to problems in one or more of five categories. Their solutions are presented in this proceedings along with the comparisons of their solutions to the benchmark solutions or experimental data. The five categories for the benchmark problems were as follows: Category 1:Basic Methods. The numerical computation of sound is affected by, among other issues, the choice of grid used and by the boundary conditions. Category 2:Complex Geometry. The ability to compute the sound in the presence of complex geometric surfaces is important in practical applications of CAA. Category 3:Sound Generation by Interacting With a Gust. The practical application of CAA for computing noise generated by turbomachinery involves the modeling of the noise source mechanism as a vortical gust interacting with an airfoil. Category 4:Sound Transmission and Radiation. Category 5:Sound Generation in Viscous Problems. Sound is generated under certain conditions by a viscous flow as the flow passes an object or a cavity.

Dahl, Milo D. (Editor)

2004-01-01

27

RADIOGRAPHIC BENCHMARK PROBLEM 2009 - SCATTER CALCULATIONS IN MODELLING  

SciTech Connect

Code Validation is a permanent concern in computer simulation, and has been addressed repeatedly in eddy current and ultrasonic modelling. A good benchmark problem is sufficiently simple to be taken into account by various codes without strong requirements on geometry representation capabilities, focuses on few or even a single aspect of the problem at hand to facilitate interpretation and to avoid that compound errors compensate themselves, yields a quantitative result and is experimentally accessible. In this paper we attempt to address code validation for one aspect of radio-graphic modelling, the scattered radiation prediction. An update of the results of the 2008 benchmark is presented. Additionally we discuss the extension of this benchmark on the lower energy part for 60 and 80 keV as well as for higher energies up to 10 MeV to study the contribution of pair production. Of special interest will be the primary radiation (attenuation law as reference), the total scattered radiation, the relative contribution of scattered radiation separated by order of scatter events (1st, 2nd, ..., 20th), and the spectrum of scattered radiation. We present the results of three Monte Carlo codes (MC-Ray, Sindbad and Moderato) as well as an analytical first order scattering code (VXI) and compare to MCNP as reference.

Jaenisch, G.-R.; Bellon, C. [Bundesanstalt fuer Materialforschung und -pruefung, Unter den Eichen 87, 12205 Berlin (Germany); Schumm, A. [Electricite de France R and D, 1 avenue du general de Gaulle, 92141 Clamart (France); Tabary, J. [CEA, LETI, MINATEC, F38054 Grenoble (France); Duvauchelle, Ph. [INSA-Lyon, Laboratoire de Controle Non Destructif par Rayonnements Ionisants Bat Saint Exupery, 20 avenue Albert Einstein 69 621 Villeurbanne Cedex (France)

2010-02-22

28

A PROPOSED BENCHMARK PROBLEM FOR SCATTER CALCULATIONS IN RADIOGRAPHIC MODELLING  

SciTech Connect

Code Validation is a permanent concern in computer modelling, and has been addressed repeatedly in eddy current and ultrasonic modeling. A good benchmark problem is sufficiently simple to be taken into account by various codes without strong requirements on geometry representation capabilities, focuses on few or even a single aspect of the problem at hand to facilitate interpretation and to avoid that compound errors compensate themselves, yields a quantitative result and is experimentally accessible. In this paper we attempt to address code validation for one aspect of radiographic modeling, the scattered radiation prediction. Many NDT applications can not neglect scattered radiation, and the scatter calculation thus is important to faithfully simulate the inspection situation. Our benchmark problem covers the wall thickness range of 10 to 50 mm for single wall inspections, with energies ranging from 100 to 500 keV in the first stage, and up to 1 MeV with wall thicknesses up to 70 mm in the extended stage. A simple plate geometry is sufficient for this purpose, and the scatter data is compared on a photon level, without a film model, which allows for comparisons with reference codes like MCNP. We compare results of three Monte Carlo codes (McRay, Sindbad and Moderato) as well as an analytical first order scattering code (VXI), and confront them to results obtained with MCNP. The comparison with an analytical scatter model provides insights into the application domain where this kind of approach can successfully replace Monte-Carlo calculations.

Jaenisch, G.-R.; Bellon, C. [Bundesanstalt fuer Materialforschung und-pruefung, Unter den Eichen 87, 12205 Berlin (Germany); Schumm, A. [Electricite de France R and D, 1 avenue du general de Gaulle, 92141 Clamart (France); Tabary, J. [CEA, LETI, MINATEC, F38054 Grenoble (France); Duvauchelle, Ph. [INSA-Lyon, Laboratoire de Controle Non Destructif par Rayonnements Ionisants Bat Saint Exupery, 20 avenue Albert Einstein 69 621 Villeurbanne Cedex (France)

2009-03-03

29

Numerical Boundary Conditions for Computational Aeroacoustics Benchmark Problems  

NASA Technical Reports Server (NTRS)

Category 1, Problems 1 and 2, Category 2, Problem 2, and Category 3, Problem 2 are solved computationally using the Dispersion-Relation-Preserving (DRP) scheme. All these problems are governed by the linearized Euler equations. The resolution requirements of the DRP scheme for maintaining low numerical dispersion and dissipation as well as accurate wave speeds in solving the linearized Euler equations are now well understood. As long as 8 or more mesh points per wavelength is employed in the numerical computation, high quality results are assured. For the first three categories of benchmark problems, therefore, the real challenge is to develop high quality numerical boundary conditions. For Category 1, Problems 1 and 2, it is the curved wall boundary conditions. For Category 2, Problem 2, it is the internal radiation boundary conditions inside the duct. For Category 3, Problem 2, they are the inflow and outflow boundary conditions upstream and downstream of the blade row. These are the foci of the present investigation. Special nonhomogeneous radiation boundary conditions that generate the incoming disturbances and at the same time allow the outgoing reflected or scattered acoustic disturbances to leave the computation domain without significant reflection are developed. Numerical results based on these boundary conditions are provided.

Tam, Chritsopher K. W.; Kurbatskii, Konstantin A.; Fang, Jun

1997-01-01

30

Comet solutions to a stylized BWR benchmark problem  

SciTech Connect

In this paper, a stylized 3-D BWR benchmark problem was used to evaluate the performance of the coarse mesh radiation transport method COMET. The benchmark problem consists of 560 fuel bundles at 3 different burnups and 3 coolant void states. The COMET solution was compared with the corresponding Monte Carlo reference solution using the same 2-group material cross section library for three control blade (rod) configurations, namely, all rods out (ARO), all rods in (ARI) and some rods in (SRJ). The differences in the COMET and MCNP eigenvalues were 43 pcm, 66 pcm and 32 pcm for the ARO, ARI and SRI cases, respectively. These differences are all within 3 standard deviations of the COMET uncertainty. The average relative differences in the bundle averaged fission densities for these three cases were 0.89%, 1.24%, and 1.05%, respectively. The corresponding differences in the fuel pin averaged fission densities were 1.24%, 1.84% and 1.29%, respectively. It was found that COMET is 3,000 times faster than Monte Carlo, while its statistical uncertainty in the fuel pin fission density is much lower than that of Monte Carlo (i.e., {approx}40 times lower). (authors)

Zhang, D.; Rahnema, F. [Georgia Inst. of Technology, 770 State Street, Atlanta, GA 30332-0745 (United States)

2012-07-01

31

Pericles and Attila results for the C5G7 MOX benchmark problems  

SciTech Connect

Recently the Nuclear Energy Agency has published a new benchmark entitled, 'C5G7 MOX Benchmark.' This benchmark is to test the ability of current transport codes to treat reactor core problems without spatial homogenization. The benchmark includes both a two- and three-dimensional problem. We have calculated results for these benchmark problems with our Pericles and Attila codes. Pericles is a one-,two-, and three-dimensional unstructured grid discrete-ordinates code and was used for the twodimensional benchmark problem. Attila is a three-dimensional unstructured tetrahedral mesh discrete-ordinate code and was used for the three-dimensional problem. Both codes use discontinuous finite element spatial differencing. Both codes use diffusion synthetic acceleration (DSA) for accelerating the inner iterations.

Wareing, T. A. (Todd A.); McGhee, J. M. (John M.)

2002-01-01

32

A Benchmark Problem for Development of Autonomous Structural Modal Identification  

NASA Technical Reports Server (NTRS)

This paper summarizes modal identification results obtained using an autonomous version of the Eigensystem Realization Algorithm on a dynamically complex, laboratory structure. The benchmark problem uses 48 of 768 free-decay responses measured in a complete modal survey test. The true modal parameters of the structure are well known from two previous, independent investigations. Without user involvement, the autonomous data analysis identified 24 to 33 structural modes with good to excellent accuracy in 62 seconds of CPU time (on a DEC Alpha 4000 computer). The modal identification technique described in the paper is the baseline algorithm for NASA's Autonomous Dynamics Determination (ADD) experiment scheduled to fly on International Space Station assembly flights in 1997-1999.

Pappa, Richard S.; Woodard, Stanley E.; Juang, Jer-Nan

1996-01-01

33

Benchmark problems for defect size and shape determination in eddy-current nondestructive evaluation  

Microsoft Academic Search

A set of four benchmark problems is presented for verification of theoretical calculations of defect size and shape in eddy-current nondestructive evaluation. The benchmark problems are based on careful measurements of the change in coil impedance as a function of frequency for a circular air-cored coil which is scanned along the axis of an electrodischarge machined slot in a thick

D. J. Harrison; L. D. Jones; S. K. Burke

1996-01-01

34

Identification of significant problems related to light water reactor piping systems  

SciTech Connect

Work on the project was divided into three tasks. In Task 1, past surveys of LWR piping system problems and recent Licensee Event Report summaries are studied to identify the significant problems of LWR piping systems and the primary causes of these problems. Pipe cracking is identified as the most recurring problem and is mainly due to the vibration of pipes due to operating pump-pipe resonance, fluid-flow fluctuations, and vibration of pipe supports. Research relevant to the identified piping system problems is evaluated. Task 2 studies identify typical LWR piping systems and the current loads and load combinations used in the design of these systems. Definitions of loads are reviewed. In Task 3, a comparative study is carried out on the use of nonlinear analysis methods in the design of LWR piping systems. The study concludes that the current linear-elastic methods of analysis may not predict accurately the behavior of piping systems under seismic loads and may, under certain circumstances, result in nonconservative designs. Gaps at piping supports are found to have a significant effect on the response of the piping systems.

None

1980-07-01

35

COMET solutions to whole core CANDU-6 benchmark problems  

SciTech Connect

In this paper, the coarse mesh transport code COMET is used to solve CANDU-6 benchmark problems in two and three dimensional geometry. These problems are representative of a simplified quarter core reactor model. The COMET solutions, the core eigenvalue and the fuel pin fission density distribution, are compared to those from the Monte Carlo code MCNP using two-group cross sections. COMET decomposes the core volume into a set of non-overlapping sub-volumes (coarse meshes) and uses pre-computed heterogeneous response functions that are constructed using Legendre polynomials as boundary conditions to generate a user selected whole core solution (e.g., the core eigenvalue and fuel pin fission density distribution). These response functions are pre-computed by performing fixed source calculations with a modified version of MCNP in only the unique coarse meshes in the core. Reference solutions are calculated by MCNP5 with a two-group energy library generated with the HELIOS lattice code. In the 2-D problem, the angular current on the coarse mesh interfaces in COMET is expanded to 2. order in both spatial and angular variables. The COMET eigenvalue error is 0.09%. The corresponding average error in the fission density over all 3515 fuel pins is 0.5%. The maximum error observed is 2.0%. For the 3-D case, with 4. order expansion in space and azimuthal angle and 2. order expansion in the cosine of the polar angle, the eigenvalue differs from the reference solution by 0.05%. The average fission density error over the 42180 fuel pins is 0.7% with a maximum error of 3.3%. (authors)

Forget, B.; Rahnema, F. [Nuclear and Radiological Engineering / Medical Physics Programs, George W. Woodruff School, Georgia Inst. of Technology, Atlanta, GA 30332-0405 (United States)

2006-07-01

36

Benchmark on Anisotropic Problems Numerical investigation of a mimetic finite difference method  

E-print Network

Benchmark on Anisotropic Problems Numerical investigation of a mimetic finite difference method@iws.uni-stuttgart.de ABSTRACT. This benchmark study investigates the behavior of a mimetic finite difference method. It solves, mimetic finite difference method 1. Presentation of the scheme Mimetic finite difference methods

Cirpka, Olaf Arie

37

Single pin BWR benchmark problem for coupled Monte Carlo - Thermal hydraulics analysis  

SciTech Connect

As part of the European NURISP research project, a single pin BWR benchmark problem was defined. The aim of this initiative is to test the coupling strategies between Monte Carlo and subchannel codes developed by different project participants. In this paper the results obtained by the Delft Univ. of Technology and Karlsruhe Inst. of Technology will be presented. The benchmark problem was simulated with the following coupled codes: TRIPOLI-SUBCHANFLOW, MCNP-FLICA, MCNP-SUBCHANFLOW, and KENO-SUBCHANFLOW. (authors)

Ivanov, A.; Sanchez, V. [Karlsruhe Inst. of Technology, Inst. for Neutron Physics and Reactor Technology, Herman-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Hoogenboom, J. E. [Delft Univ. of Technology, Faculty of Applied Sciences, Mekelweg 15, 2629 JB Delft (Netherlands)

2012-07-01

38

Finite element spherical harmonics (P N ) solutions of the three-dimensional Takeda benchmark problems  

Microsoft Academic Search

A set of multi-group eigenvalue (Keff) benchmark problems in three-dimensional homogenised reactor core configurations have been solved using the deterministic finite element transport theory code EVENT and the Monte Carlo code MCNP4C. The principal aim of this work is to qualify numerical methods and algorithms implemented in EVENT. The benchmark problems were compiled and published by the Nuclear Data Agency

A. K. Ziver; M. S. Shahdatullah; M. D. Eaton; C. R. E. de Oliveira; A. P. Umpleby; C. C. Pain; A. J. H. Goddard

2005-01-01

39

Sonic limitations and startup problems of heat pipes  

NASA Technical Reports Server (NTRS)

Introduction of small amounts of inert, noncombustible gas aids startup in certain types of heat pipes. When the heat pipe is closely coupled to the heat sink, the startup system must be designed to bring the heat sink on-line slowly.

Deverall, J. E.; Kemme, J. E.; Florschuetz, L. W.

1972-01-01

40

Large Core Code Evaluation Working Group Benchmark Problem Four: neutronics and burnup analysis of a large heterogeneous fast reactor. Part 1. Analysis of benchmark results. [LMFBR  

Microsoft Academic Search

The Large Core Code Evaluation Working Group Benchmark Problem Four was specified to provide a stringent test of the current methods which are used in the nuclear design and analyses process. The benchmark specifications provided a base for performing detailed burnup calculations over the first two irradiation cycles for a large heterogeneous fast reactor. Particular emphasis was placed on the

C. L. Cowan; R. Protsik; J. W. Lewellen

1984-01-01

41

Comparison of Numerical Schemes for a Realistic Computational Aeroacoustics Benchmark Problem  

NASA Technical Reports Server (NTRS)

In this work, a nonlinear structured-multiblock CAA solver, the NASA GRC BASS code, will be tested on a realistic CAA benchmark problem. The purpose of this test is to ascertain what effect the high-accuracy solution methods used in CAA have on a realistic test problem, where both the mean flow and the unsteady waves are simultaneously computed on a fully curvilinear grid from a commercial grid generator. The proposed test will compare the solutions obtained using several finite-difference methods on identical grids to determine whether high-accuracy schemes have advantages for this benchmark problem.

Hixon, R.; Wu, J.; Nallasamy, M.; Sawyer, S.; Dyson, R.

2004-01-01

42

Clad piping - a novel approach for solving nuclear plant service water and erosion-corrosion problems  

SciTech Connect

This paper discusses the application of clad piping components to solve various nuclear plant corrosion problems, such as service water system corrosion and feedwater/condensate/steam erosion-corrosion. This approach uses a carbon steel piping component which has a metallurgically bonded alloy cladding on the ID. Different alloys are available as cladding, from stainless steels to Inconel 625, so that a specific alloy can be selected based on the service requirements. Clad piping components represent a novel approach, as they provide a mechanism to utilize resistant alloys to solve corrosion problems without affecting the plant design. Clad piping products are designed such that the carbon steel backing acts as the pressure boundary and the cladding the corrosion allowance. By selecting the proper carbon steel backing, the clad product can be engineered to allow {open_quotes}like-for-like{close_quotes} component replacement. The wall thickness, weight and stiffness of the piping would remain essentially the same. The thermal expansion coefficient of the bulk piping also remains the same. Thus, the piping design and layout is wholly unaffected, with no structural reanalysis being required. This paper discusses two applications where clad piping products are being applied for solving nuclear power plant corrosion problems. The first is in solving steam/condensate/feedwater erosion-corrosion. The second application is the utilization of Inconel 625 clad piping products for solving service water system corrosion. Clad piping products solve these problems while improving plant operation and performance by basically providing the benefits of the alloy without any of the accompanying disadvantages of redesign.

Chakravarti, B. [NUTECH Engineers, Inc., Westmont, IL (United States)

1992-12-31

43

A comparative study of differential evolution, particle swarm optimization, and evolutionary algorithms on numerical benchmark problems  

Microsoft Academic Search

Several extensions to evolutionary algorithms (EAs) and particle swarm optimization (PSO) have been suggested during the last decades offering improved performance on selected benchmark problems. Recently, another search heuristic termed differential evolution (DE) has shown superior performance in several real-world applications. In this paper, we evaluate the performance of DE, PSO, and EAs regarding their general applicability as numerical optimization

J. Vesterstrom; R. Thomsen

2004-01-01

44

Exact analytical solutions for some popular benchmark problems in topology optimization III: L -shaped domains  

Microsoft Academic Search

In this paper exact, analytical solutions are derived for another highly popular benchmark problem, namely, L-shaped domains having a horizontal line support and one or several point loads. The optimal topologies are obtained in the\\u000a context of Michell structures, i.e., least-weight, stress, or compliance-controlled trusses with a single load condition.

T. Lewi?ski; G. I. N. Rozvany

2008-01-01

45

Results of Benchmark Problems for the Third Computational Aeroacoustics Workshop  

E-print Network

values of the flow. The nozzle flow is modeled by the one­dimensional Euler equations with variable]. Propagation of sound waves through transonic nozzle In this problem, an acoustic wave is introduced at the nozzle exit region and the sound wave that travels upstream through the transonic nozzle

Hu, Fang Q.

46

Results of Benchmark Problems for the Third Computational Aeroacoustics Workshop  

E-print Network

of the flow. The nozzle flow is modeled by the one-dimensional Euler equations with variable nozzle area]. Propagation of sound waves through transonic nozzle In this problem, an acoustic wave is introduced at the nozzle exit region and the sound wave that travels upstream through the transonic nozzle

Hu, Fang Q.

47

A Benchmark for Methods in Reverse Engineering and Model Discrimination: Problem Formulation and Solutions  

PubMed Central

A benchmark problem is described for the reconstruction and analysis of biochemical networks given sampled experimental data. The growth of the organisms is described in a bioreactor in which one substrate is fed into the reactor with a given feed rate and feed concentration. Measurements for some intracellular components are provided representing a small biochemical network. Problems of reverse engineering, parameter estimation, and identifiability are addressed. The contribution mainly focuses on the problem of model discrimination. If two or more model variants describe the available experimental data, a new experiment must be designed to discriminate between the hypothetical models. For the problem presented, the feed rate and feed concentration of a bioreactor system are available as control inputs. To verify calculated input profiles an interactive Web site (http://www.sysbio.de/projects/benchmark/) is provided. Several solutions based on linear and nonlinear models are discussed. PMID:15342560

Kremling, Andreas; Fischer, Sophia; Gadkar, Kapil; Doyle, Francis J.; Sauter, Thomas; Bullinger, Eric; Allgöwer, Frank; Gilles, Ernst D.

2004-01-01

48

TOPS nodal code solutions for the OECD/PBMR-400 benchmark problem  

SciTech Connect

This paper provides the solution of the OECD/PBMR-400 benchmark problem by the TOPS code based on the Analytic Function Expansion Nodal (AFEN) method in 3-D cylindrical geometry. The paper is focused on the multi-group methodology, two methods (partial current translation and AFEN formulation) of treating the void regions, and comparison of the their results. We also suggest a modified benchmark problem, which does not have void regions where special treatments are required, to be used to verify the calculational methods in cylindrical geometry. The results indicate that the effect of void regions is significant and that the method how to treat the voids in computation is important. (authors)

Lee, J.; Lee, J. H.; Yoo, H. J.; Lee, G. S.; Cho, N. Z. [Korea Advanced Inst. of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Daejeon (Korea, Republic of)

2006-07-01

49

MC21 analysis of the nuclear energy agency Monte Carlo performance benchmark problem  

SciTech Connect

Due to the steadily decreasing cost and wider availability of large scale computing platforms, there is growing interest in the prospects for the use of Monte Carlo for reactor design calculations that are currently performed using few-group diffusion theory or other low-order methods. To facilitate the monitoring of the progress being made toward the goal of practical full-core reactor design calculations using Monte Carlo, a performance benchmark has been developed and made available through the Nuclear Energy Agency. A first analysis of this benchmark using the MC21 Monte Carlo code was reported on in 2010, and several practical difficulties were highlighted. In this paper, a newer version of MC21 that addresses some of these difficulties has been applied to the benchmark. In particular, the confidence-interval-determination method has been improved to eliminate source correlation bias, and a fission-source-weighting method has been implemented to provide a more uniform distribution of statistical uncertainties. In addition, the Forward-Weighted, Consistent-Adjoint-Driven Importance Sampling methodology has been applied to the benchmark problem. Results of several analyses using these methods are presented, as well as results from a very large calculation with statistical uncertainties that approach what is needed for design applications. (authors)

Kelly, D. J.; Sutton, T. M. [Knolls Atomic Power Laboratory, Bechtel Marine Propulsion Corporation, P. O. Box 1072, Schenectady, NY 12301-1072 (United States); Wilson, S. C. [Bertis Atomic Power Laboratory, Bechtel Marine Propulsion Corporation, P. O. Box 79, West Mifflin, PA 15122-0079 (United States)

2012-07-01

50

Whole-core comet solutions to a 3-dimensional PWR benchmark problem with gadolinium  

SciTech Connect

A pressurized water reactor (PWR) benchmark problem with gadolinium was used to determine the accuracy and computational efficiency of the coarse mesh radiation transport method COMET. The benchmark problem contains 193 square fuel assemblies. The COMET solution (eigenvalue, assembly averaged and fuel pin averaged fission density distributions) was compared with those obtained from the corresponding Monte Carlo reference solution using the same 2-group material cross section library. The comparison showed that both the core eigenvalue and fission density distribution averaged over each assembly and fuel pin predicated by COMET agree very well with the corresponding MCNP reference solution if the incident flux response expansion used in COMET is truncated at 2nd order in the two spatial and the two angular variables. The benchmark calculations indicate that COMET has Monte Carlo accuracy. In, particular, the eigenvalue difference between the codes ranged from 17 pcm to 35 pcm, being within 2 standard deviations of the calculational uncertainty. The mean flux weighted relative differences in the assembly and fuel pin fission densities were 0.47% and 0.65%, respectively. It was also found that COMET's full (whole) core computational speed is 30,000 times faster than MCNP in which only 1/8 of the core is modeled. It is estimated that COMET would have been about over 6 orders of magnitude faster than MCNP if the full core were also modeled in MCNP. (authors)

Zhang, D.; Rahnema, F. [Georgia Inst. of Technology, 770 State Street, Atlanta, GA 30332-0745 (United States)

2012-07-01

51

Benchmark solutions for the galactic ion transport equations: Energy and spatially dependent problems  

NASA Technical Reports Server (NTRS)

Nontrivial benchmark solutions are developed for the galactic ion transport (GIT) equations in the straight-ahead approximation. These equations are used to predict potential radiation hazards in the upper atmosphere and in space. Two levels of difficulty are considered: (1) energy independent, and (2) spatially independent. The analysis emphasizes analytical methods never before applied to the GIT equations. Most of the representations derived have been numerically implemented and compared to more approximate calculations. Accurate ion fluxes are obtained (3 to 5 digits) for nontrivial sources. For monoenergetic beams, both accurate doses and fluxes are found. The benchmarks presented are useful in assessing the accuracy of transport algorithms designed to accommodate more complex radiation protection problems. In addition, these solutions can provide fast and accurate assessments of relatively simple shield configurations.

Ganapol, Barry D.; Townsend, Lawrence W.; Wilson, John W.

1989-01-01

52

TOPAZ - the transient one-dimensional pipe flow analyzer: code validation and sample problems  

SciTech Connect

TOPAZ is a ''user friendly'' computer code for modeling the one-dimensional-transient physics of multi-species gas transfer in arbitrary arrangements of pipes, valves, vessels, and flow branches. This document presents a series of sample problems designed to aid potential users in creating TOPAZ input files. To the extent possible, sample problems were selected for which analytical solutions currently exist. TOPAZ comparisons with such solutions are intended to provide a measure of code validation.

Winters, W.S.

1985-10-01

53

TOPAZ - the transient one-dimensional pipe flow analyzer: code validation and sample problems  

Microsoft Academic Search

TOPAZ is a ''user friendly'' computer code for modeling the one-dimensional-transient physics of multi-species gas transfer in arbitrary arrangements of pipes, valves, vessels, and flow branches. This document presents a series of sample problems designed to aid potential users in creating TOPAZ input files. To the extent possible, sample problems were selected for which analytical solutions currently exist. TOPAZ comparisons

Winters

1985-01-01

54

Benchmark Solution For The Category 3, Problem 2: Cascade - Gust Interaction  

NASA Technical Reports Server (NTRS)

The benchmark solution for the cascade-gust interaction problem is computed using a linearized Euler code called LINFLUX. The inherently three-dimensional code is run in the thin-annulus limit to compute the two-dimensional cascade response. The calculations are carried out in the frequency-domain and the unsteady response at each of the gust s three frequency component is computed. The results are presented on modal basis for pressure perturbations (i.e., acoustic modes) as well as velocity perturbations (i.e., convected gust modes) at each frequency.

Envia, Edmane

2004-01-01

55

Validation of depth-averaged flow model using flat-bottomed benchmark problems.  

PubMed

In this study, a shallow water flow code was developed and tested against four benchmark problems of practical relevance. The results demonstrated that as the eddy viscosity increased, the velocity slope along the spanwise direction decreased, and the larger roughness coefficient induced a higher flow depth over the channel width. The mass conservation rate was determined to be 99.2%. This value was measured by the variation of the total volume of the fluid after a cylinder break. As the Re increased to 10,000 in the internal recirculating flow problem, the intensity of the primary vortex had a clear trend toward the theoretically infinite Re value of -1.886. The computed values of the supercritical flow evolved by the oblique hydraulic jump agreed well with the analytic solutions within an error bound of 0.2%. The present model adopts the nonconservative form of shallow water equations. These equations are weighted by the SU/PG scheme and integrated by a fully implicit method, which can reproduce physical problems with various properties. The model provides excellent results under various flow conditions, and the solutions of benchmark tests can present criteria for the evaluation of various algorithmic approaches. PMID:24982929

Seo, Il Won; Kim, Young Do; Song, Chang Geun

2014-01-01

56

Validation of Depth-Averaged Flow Model Using Flat-Bottomed Benchmark Problems  

PubMed Central

In this study, a shallow water flow code was developed and tested against four benchmark problems of practical relevance. The results demonstrated that as the eddy viscosity increased, the velocity slope along the spanwise direction decreased, and the larger roughness coefficient induced a higher flow depth over the channel width. The mass conservation rate was determined to be 99.2%. This value was measured by the variation of the total volume of the fluid after a cylinder break. As the Re increased to 10,000 in the internal recirculating flow problem, the intensity of the primary vortex had a clear trend toward the theoretically infinite Re value of ?1.886. The computed values of the supercritical flow evolved by the oblique hydraulic jump agreed well with the analytic solutions within an error bound of 0.2%. The present model adopts the nonconservative form of shallow water equations. These equations are weighted by the SU/PG scheme and integrated by a fully implicit method, which can reproduce physical problems with various properties. The model provides excellent results under various flow conditions, and the solutions of benchmark tests can present criteria for the evaluation of various algorithmic approaches. PMID:24982929

Seo, Il Won; Kim, Young Do; Song, Chang Geun

2014-01-01

57

A new algorithm for generating highly accurate benchmark solutions to transport test problems  

SciTech Connect

We present a new algorithm for solving the neutron transport equation in its discrete-variable form. The new algorithm is based on computing the full matrix relating the scalar flux spatial moments in all cells to the fixed neutron source spatial moments, foregoing the need to compute the angular flux spatial moments, and thereby eliminating the need for sweeping the spatial mesh in each discrete-angular direction. The matrix equation is solved exactly in test cases, producing a solution vector that is free from iteration convergence error, and subject only to truncation and roundoff errors. Our algorithm is designed to provide method developers with a quick and simple solution scheme to test their new methods on difficult test problems without the need to develop sophisticated solution, e.g. acceleration, algorithms before establishing the worthiness of their innovation. We demonstrate the utility of the new algorithm by applying it to the Arbitrarily High Order Transport Nodal (AHOT-N) method, and using it to solve Burre`s Test Problem, a suite of benchmark problems that covers a large region in parameter space. Our results provide highly accurate benchmark solutions, that can be distributed electronically and used to verify the pointwise accuracy of other solution methods and algorithms.

Azmy, Y.Y.

1995-03-01

58

MHD and heat transfer benchmark problems for liquid metal flow in rectangular ducts  

SciTech Connect

Liquid metal cooling systems of a self-cooled blanket in a tokamak reactor will likely include channels of rectangular cross section where liquid metal is circulated in the presence of strong magnetic fields. MHD pressure drop, velocity distribution and heat transfer characteristics are important issues in the engineering design considerations. Computer codes for the reliable solution of three-dimensional MHD flow problems are needed for fusion relevant conditions. Argonne National Laboratory and The Efremov Institute have jointly defined several benchmark problems for code validation. The problems, described in this paper, are based on two series of rectangular duct experiments conducted at ANL; one of the series is a joint ANL/Efremov experiment. The geometries consist of variation of aspect ratio and wall thickness (thus wall conductance ratio). The transverse magnetic fields are uniform and nonuniform in the axial direction.

Sidorenkov, S.I. [D.V. Efremov Scientific Research Inst. of Electrophysical Apparatus, St. Petersburg (Russian Federation); Hua, T.Q. [Argonne National Lab., IL (United States); Araseki, H. [Central Research Inst. of Electric Power Industry, Tokoyo (Japan)

1994-12-31

59

A Study of Fixed-Order Mixed Norm Designs for a Benchmark Problem in Structural Control  

NASA Technical Reports Server (NTRS)

This study investigates the use of H2, p-synthesis, and mixed H2/mu methods to construct full-order controllers and optimized controllers of fixed dimensions. The benchmark problem definition is first extended to include uncertainty within the controller bandwidth in the form of parametric uncertainty representative of uncertainty in the natural frequencies of the design model. The sensitivity of H2 design to unmodelled dynamics and parametric uncertainty is evaluated for a range of controller levels of authority. Next, mu-synthesis methods are applied to design full-order compensators that are robust to both unmodelled dynamics and to parametric uncertainty. Finally, a set of mixed H2/mu compensators are designed which are optimized for a fixed compensator dimension. These mixed norm designs recover the H, design performance levels while providing the same levels of robust stability as the u designs. It is shown that designing with the mixed norm approach permits higher levels of controller authority for which the H, designs are destabilizing. The benchmark problem is that of an active tendon system. The controller designs are all based on the use of acceleration feedback.

Whorton, Mark S.; Calise, Anthony J.; Hsu, C. C.

1998-01-01

60

ICASE/LaRC Workshop on Benchmark Problems in Computational Aeroacoustics (CAA)  

NASA Technical Reports Server (NTRS)

The proceedings of the Benchmark Problems in Computational Aeroacoustics Workshop held at NASA Langley Research Center are the subject of this report. The purpose of the Workshop was to assess the utility of a number of numerical schemes in the context of the unusual requirements of aeroacoustical calculations. The schemes were assessed from the viewpoint of dispersion and dissipation -- issues important to long time integration and long distance propagation in aeroacoustics. Also investigated were the effect of implementation of different boundary conditions. The Workshop included a forum in which practical engineering problems related to computational aeroacoustics were discussed. This discussion took the form of a dialogue between an industrial panel and the workshop participants and was an effort to suggest the direction of evolution of this field in the context of current engineering needs.

Hardin, Jay C. (editor); Ristorcelli, J. Ray (editor); Tam, Christopher K. W. (editor)

1995-01-01

61

The Problem with the Linpack Benchmark Matrix Generator June 28, 2008  

E-print Network

to rank computer systems based on the results obtained on the High Performance Linpack (HPL) Benchmark number generator, must be used in running the HPL benchmark. The supplied matrix generator can be found in HPL [2] which is an implementation of the High Performance Computing Linpack Benchmark. In the HPL

Dongarra, Jack

62

C5 Benchmark Problem with Discrete Ordinate Radiation Transport Code DENOVO  

SciTech Connect

The C5 benchmark problem proposed by the Organisation for Economic Co-operation and Development/Nuclear Energy Agency was modeled to examine the capabilities of Denovo, a three-dimensional (3-D) parallel discrete ordinates (S{sub N}) radiation transport code, for problems with no spatial homogenization. Denovo uses state-of-the-art numerical methods to obtain accurate solutions to the Boltzmann transport equation. Problems were run in parallel on Jaguar, a high-performance supercomputer located at Oak Ridge National Laboratory. Both the two-dimensional (2-D) and 3-D configurations were analyzed, and the results were compared with the reference MCNP Monte Carlo calculations. For an additional comparison, SCALE/KENO-V.a Monte Carlo solutions were also included. In addition, a sensitivity analysis was performed for the optimal angular quadrature and mesh resolution for both the 2-D and 3-D infinite lattices of UO{sub 2} fuel pin cells. Denovo was verified with the C5 problem. The effective multiplication factors, pin powers, and assembly powers were found to be in good agreement with the reference MCNP and SCALE/KENO-V.a Monte Carlo calculations.

Yesilyurt, Gokhan [ORNL; Clarno, Kevin T [ORNL; Evans, Thomas M [ORNL; Davidson, Gregory G [ORNL; Fox, Patricia B [ORNL

2011-01-01

63

Solutions of the benchmark problems by the dispersion-relation-preserving scheme  

NASA Technical Reports Server (NTRS)

The 7-point stencil Dispersion-Relation-Preserving scheme of Tam and Webb is used to solve all the six categories of the CAA benchmark problems. The purpose is to show that the scheme is capable of solving linear, as well as nonlinear aeroacoustics problems accurately. Nonlinearities, inevitably, lead to the generation of spurious short wave length numerical waves. Often, these spurious waves would overwhelm the entire numerical solution. In this work, the spurious waves are removed by the addition of artificial selective damping terms to the discretized equations. Category 3 problems are for testing radiation and outflow boundary conditions. In solving these problems, the radiation and outflow boundary conditions of Tam and Webb are used. These conditions are derived from the asymptotic solutions of the linearized Euler equations. Category 4 problems involved solid walls. Here, the wall boundary conditions for high-order schemes of Tam and Dong are employed. These conditions require the use of one ghost value per boundary point per physical boundary condition. In the second problem of this category, the governing equations, when written in cylindrical coordinates, are singular along the axis of the radial coordinate. The proper boundary conditions at the axis are derived by applying the limiting process of r approaches 0 to the governing equations. The Category 5 problem deals with the numerical noise issue. In the present approach, the time-independent mean flow solution is computed first. Once the residual drops to the machine noise level, the incident sound wave is turned on gradually. The solution is marched in time until a time-periodic state is reached. No exact solution is known for the Category 6 problem. Because of this, the problem is formulated in two totally different ways, first as a scattering problem then as a direct simulation problem. There is good agreement between the two numerical solutions. This offers confidence in the computed results. Both formulations are solved as initial value problems. As such, no Kutta condition is required at the trailing edge of the airfoil.

Tam, Christopher K. W.; Shen, H.; Kurbatskii, K. A.; Auriault, L.

1995-01-01

64

Theoretical analysis of the worthiness of Henry and Elder problems as benchmarks of density-dependent groundwater  

E-print Network

-dependent groundwater flow models M.J. Simpson a , T.P. Clement a,b,* a Centre for Water Research, Department the availability of benchmark problems for testing density-dependent groundwater models is limited, one should: Groundwater-modeling; Density-dependent flow; Unsaturated flow; Contaminant transport 1. Introduction

Clement, Prabhakar

65

A new algorithm for generating highly accurate benchmark solutions to transport test problems  

SciTech Connect

We present a new algorithm for solving the neutron transport equation in its discrete-variable form. The new algorithm is based on computing the full matrix relating the scalar flux spatial moments in all cells to the fixed neutron source spatial moments, foregoing the need to compute the angular flux spatial moments, and thereby eliminating the need for sweeping the spatial mesh in each discrete-angular direction. The matrix equation is solved exactly in test cases, producing a solution vector that is free from iteration convergence error, and subject only to truncation and roundoff errors. Our algorithm is designed to provide method developers with a quick and simple solution scheme to test their new methods on difficult test problems without the need to develop sophisticated solution techniques, e.g. acceleration, before establishing the worthiness of their innovation. We demonstrate the utility of the new algorithm by applying it to the Arbitrarily High Order Transport Nodal (AHOT-N) method, and using it to solve two of Burre`s Suite of Test Problems (BSTP). Our results provide highly accurate benchmark solutions, that can be distributed electronically and used to verify the pointwise accuracy of other solution methods and algorithms.

Azmy, Y.Y.

1997-06-01

66

NAS Parallel Benchmark Results  

Microsoft Academic Search

The NAS Parallel Benchmarks have been developed at NASA Ames Research Center to studythe performance of parallel supercomputers. The eight benchmark problems are specified in a"pencil and paper" fashion. In other words, the complete details of the problem to be solved aregiven in a technical document, and except for a few restrictions, benchmarkers are free to selectthe language constructs and

Subhash Saini; David H. Bailey

1995-01-01

67

Practical analytical solutions for benchmarking of 2-D and 3-D geodynamic Stokes problems with variable viscosity  

NASA Astrophysics Data System (ADS)

Geodynamic modeling often involves challenging computations involving solution of Stokes and continuity equations under condition of highly variable viscosity. Based on new analytical approach we developed generalized analytical solutions for 2-D and 3-D incompressible Stokes flows with both linearly and exponentially variable viscosity. We demonstrated how these generalized solutions can be converted into 2-D and 3-D test problems suitable for benchmarking numerical codes aimed at modeling various mantle convection and lithospheric dynamics problems. Main advantage of this new generalized approach is that large variety of benchmark solutions can be generated including relatively complex cases with open model boundaries, non-vertical gravity and variable gradients of viscosity and density fields, which are not parallel to Cartesian axes. Examples of respective 2-D and 3-D MatLab codes are provided with this paper.

Popov, I. Yu.; Lobanov, I. S.; Popov, S. I.; Popov, A. I.; Gerya, T. V.

2013-12-01

68

Practical analytical solutions for benchmarking of 2-D and 3-D geodynamic Stokes problems with variable viscosity  

NASA Astrophysics Data System (ADS)

Geodynamic modeling is often related with challenging computations involving solution of the Stokes and continuity equations under the condition of highly variable viscosity. Based on a new analytical approach we have developed particular analytical solutions for 2-D and 3-D incompressible Stokes flows with both linearly and exponentially variable viscosity. We demonstrate how these particular solutions can be converted into 2-D and 3-D test problems suitable for benchmarking numerical codes aimed at modeling various mantle convection and lithospheric dynamics problems. The Main advantage of this new generalized approach is that a large variety of benchmark solutions can be generated, including relatively complex cases with open model boundaries, non-vertical gravity and variable gradients of the viscosity and density fields, which are not parallel to the Cartesian axes. Examples of respective 2-D and 3-D MatLab codes are provided with this paper.

Popov, I. Yu.; Lobanov, I. S.; Popov, S. I.; Popov, A. I.; Gerya, T. V.

2014-06-01

69

Mesoscale Benchmark Demonstration Problem 1: Mesoscale Simulations of Intra-granular Fission Gas Bubbles in UO2 under Post-irradiation Thermal Annealing  

SciTech Connect

A study was conducted to evaluate the capabilities of different numerical methods used to represent microstructure behavior at the mesoscale for irradiated material using an idealized benchmark problem. The purpose of the mesoscale benchmark problem was to provide a common basis to assess several mesoscale methods with the objective of identifying the strengths and areas of improvement in the predictive modeling of microstructure evolution. In this work, mesoscale models (phase-field, Potts, and kinetic Monte Carlo) developed by PNNL, INL, SNL, and ORNL were used to calculate the evolution kinetics of intra-granular fission gas bubbles in UO2 fuel under post-irradiation thermal annealing conditions. The benchmark problem was constructed to include important microstructural evolution mechanisms on the kinetics of intra-granular fission gas bubble behavior such as the atomic diffusion of Xe atoms, U vacancies, and O vacancies, the effect of vacancy capture and emission from defects, and the elastic interaction of non-equilibrium gas bubbles. An idealized set of assumptions was imposed on the benchmark problem to simplify the mechanisms considered. The capability and numerical efficiency of different models are compared against selected experimental and simulation results. These comparisons find that the phase-field methods, by the nature of the free energy formulation, are able to represent a larger subset of the mechanisms influencing the intra-granular bubble growth and coarsening mechanisms in the idealized benchmark problem as compared to the Potts and kinetic Monte Carlo methods. It is recognized that the mesoscale benchmark problem as formulated does not specifically highlight the strengths of the discrete particle modeling used in the Potts and kinetic Monte Carlo methods. Future efforts are recommended to construct increasingly more complex mesoscale benchmark problems to further verify and validate the predictive capabilities of the mesoscale modeling methods used in this study.

Li, Yulan; Hu, Shenyang Y.; Montgomery, Robert; Gao, Fei; Sun, Xin; Tonks, Michael; Biner, Bullent; Millet, Paul; Tikare, Veena; Radhakrishnan, Balasubramaniam; Andersson , David

2012-04-11

70

Benchmark Characterization  

Microsoft Academic Search

An abstract system of benchmark characteristics that makes it possible, in the beginning of the design stage, to design with benchmark performance in mind is presented. The benchmark characteristics for a set of commonly used benchmarks are then shown. The benchmark set used includes some benchmarks from the Systems Performance Evaluation Cooperative. The SPEC programs are industry-standard applications that use

Thomas M. Conte; Wen-mei W. Hwu

1991-01-01

71

2013 eddy current benchmark problem: Solution via a coupled integral approach  

NASA Astrophysics Data System (ADS)

This work proposes a solution to the 2013 eddy current testing benchmark, published by the WFNDEC. The simulated results have been obtained by employing a newly developed semi-analytical approach, based on the coupled use of the classical Volume Integral Method (VIM) and the Boundary Element Method (BEM). An analytical overview on the coupled VIM-BEM approach is first given, in order to explain its theoretical background. Then, the results obtained are discussed from the points of view of accuracy and efficiency, respectively.

Miorelli, Roberto; Reboud, Christophe; Theodoulidis, Theodoros

2014-02-01

72

Summary of the Tandem Cylinder Solutions from the Benchmark Problems for Airframe Noise Computations-I Workshop  

NASA Technical Reports Server (NTRS)

Fifteen submissions in the tandem cylinders category of the First Workshop on Benchmark problems for Airframe Noise Computations are summarized. Although the geometry is relatively simple, the problem involves complex physics. Researchers employed various block-structured, overset, unstructured and embedded Cartesian grid techniques and considerable computational resources to simulate the flow. The solutions are compared against each other and experimental data from 2 facilities. Overall, the simulations captured the gross features of the flow, but resolving all the details which would be necessary to compute the noise remains challenging. In particular, how to best simulate the effects of the experimental transition strip, and the associated high Reynolds number effects, was unclear. Furthermore, capturing the spanwise variation proved difficult.

Lockard, David P.

2011-01-01

73

Generating, Benchmarking and Simulating Production Schedules: From Formalisation to Real Problems  

Microsoft Academic Search

Production scheduling has attracted the interest of production economics communities for decades, but there is still a gap between academic research, real-world problems, operations research and simulation. Genetic Algorithms (GA) represent a technique that has already been applied to a variety of combinatorial problems. Simulation can be used to find a solution to problems through repetitive simulation runs or to

Gert Zülch; Peter Steininger; Thilo Gamber; Michael Leupold

2009-01-01

74

Pipe Flow Simulation Software: A Team Approach to Solve an Engineering Education Problem.  

ERIC Educational Resources Information Center

A computer simulation program for use in the study of fluid mechanics is described. The package is an interactive tool to explore the fluid flow characteristics of a pipe system by manipulating the physical construction of the system. The motivation, software design requirements, and specific details on how its objectives were met are presented.…

Engel, Renata S.; And Others

1996-01-01

75

Benchmarking a Wide Spectrum of Metaheuristic Techniques for the Radio Network Design Problem  

Microsoft Academic Search

The radio network design (RND) is an NP-hard optimization problem which consists of the maximization of the coverage of a given area while minimizing the base station deployment. Solving RND problems efficiently is relevant to many fields of application and has a direct impact in the engineering, telecommunication, scientific, and industrial areas. Numerous works can be found in the literature

Silvio Priem-Mendes; Guillermo Molina; Miguel A. Vega-Rodríguez; Juan Antonio Gómez Pulido; Yago Sáez; Gara Miranda; Carlos Segura; Enrique Alba; Pedro Isasi; Coromoto León; Juan Manuel Sánchez-Pérez

2009-01-01

76

Piping Connector  

NASA Technical Reports Server (NTRS)

A complex of high pressure piping at Stennis Space Center carries rocket propellants and other fluids/gases through the Center's Component Test Facility. Conventional clamped connectors tend to leak when propellant lines are chilled to extremely low temperatures. Reflange, Inc. customized an existing piping connector to include a secondary seal more tolerant of severe thermal gradients for Stennis. The T-Con connector solved the problem, and the company is now marketing a commercial version that permits testing, monitoring or collecting any emissions that may escape the primary seal during severe thermal transition.

1993-01-01

77

Benchmarking the SPHINX and CTH shock physics codes for three problems in ballistics  

SciTech Connect

The CTH Eulerian hydrocode, and the SPHINX smooth particle hydrodynamics (SPH) code were used to model a shock tube, two long rod penetrations into semi-infinite steel targets, and a long rod penetration into a spaced plate array. The results were then compared to experimental data. Both SPHINX and CTH modeled the one-dimensional shock tube problem well. Both codes did a reasonable job in modeling the outcome of the axisymmetric rod impact problem. Neither code correctly reproduced the depth of penetration in both experiments. In the 3-D problem, both codes reasonably replicated the penetration of the rod through the first plate. After this, however, the predictions of both codes began to diverge from the results seen in the experiment. In terms of computer resources, the run times are problem dependent, and are discussed in the text.

Wilson, L.T. [Naval Surface Warfare Center, Dahlgren, VA (United States); Hertel, E. [Sandia National Labs., Albuquerque, NM (United States); Schwalbe, L.; Wingate, C. [Los Alamos National Lab., NM (United States)

1998-02-01

78

Constant-concentration boundary condition: Lessons from the HYDROCOIN variable-density groundwater benchmark problem  

USGS Publications Warehouse

In a solute-transport model, if a constant-concentration boundary condition is applied at a node in an active flow field, a solute flux can occur by both advective and dispersive processes. The potential for advective release is demonstrated by reexamining the Hydrologic Code Intercomparison (HYDROCOIN) project case 5 problem, which represents a salt dome overlain by a shallow groundwater system. The resulting flow field includes significant salinity and fluid density variations. Several independent teams simulated this problem using finite difference or finite element numerical models. We applied a method-of-characteristics model (MOCDENSE). The previous numerical implementations by HYDROCOIN teams of a constant-concentration boundary to represent salt release by lateral dispersion only (as stipulated in the original problem definition) was flawed because this boundary condition allows the release of salt into the flow field by both dispersion and advection. When the constant-concentration boundary is modified to allow salt release by dispersion only, significantly less salt is released into the flow field. The calculated brine distribution for case 5 depends very little on which numerical model is used, as long as the selected model is solving the proper equations. Instead, the accuracy of the solution depends strongly on the proper conceptualization of the problem, including the detailed design of the constant-concentration boundary condition. The importance and sensitivity to the manner of specification of this boundary does not appear to have been recognized previously in the analysis of this problem.

Konikow, L.F.; Sanford, W.E.; Campbell, P.J.

1997-01-01

79

Sensitivity of MCNP5 calculations for a spherical numerical benchmark problem to the angular scattering distributions for deuterium  

SciTech Connect

This paper examines the sensitivity of MCNP5 k{sub eff} results to various deuterium data files for a simple benchmark problem consisting of an 8.4-cm radius sphere of uranium surrounded by an annulus of deuterium at the nuclide number density corresponding to heavy water. This study was performed to help clarify why {Delta}k{sub eff} values of about 10 mk are obtained when different ENDF/B deuterium data files are used in simulations of critical experiments involving solutions of high-enrichment uranyl fluoride in heavy water, while simulations of low-leakage, heterogeneous critical lattices of natural-uranium fuel rods in heavy water show differences of <1 mk. The benchmark calculations were performed as a function of deuterium reflector thickness for several uranium compositions using deuterium ACE files derived from ENDF/B-VII.b1 (release beta 1), ENDF/B-VI.4 and JENDL-3.3, which differ primarily in the energy/angle distributions for elastic scattering <3.2 MeV. Calculations were also performed using modified ACE files having equiprobable cosine bin values in the centre-of-mass reference frame in a progressive manner with increasing energy. It was found that the {Delta}k{sub eff} values increased with deuterium reflector thickness and uranium enrichment. The studies using modified ACE files indicate that most of the reactivity differences arise at energies <1 MeV; hence, this energy range should be given priority if new scattering distribution measurements are undertaken. (authors)

Kozier, K. S. [Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ont. K0J 1J0 (Canada)

2006-07-01

80

Applicability domains for classification problems: benchmarking of distance to models for AMES mutagenicity set  

EPA Science Inventory

For QSAR and QSPR modeling of biological and physicochemical properties, estimating the accuracy of predictions is a critical problem. The ?distance to model? (DM) can be defined as a metric that defines the similarity between the training set molecules and the test set compound ...

81

CO 2 leakage through an abandoned well: problem-oriented benchmarks  

Microsoft Academic Search

The efficiency and sustainability of carbon dioxide (CO2) storage in deep geological formations crucially depends on the integrity of the overlying cap-rocks. Existing oil and gas\\u000a wells, which penetrate the formations, are potential leakage pathways. This problem has been discussed in the literature,\\u000a and a number of investigations using semi-analytical mathematical approaches have been carried out by other authors to

Anozie Ebigbo; Rainer Helmig

2007-01-01

82

Benchmarks for target tracking  

NASA Astrophysics Data System (ADS)

The term benchmark originates from the chiseled horizontal marks that surveyors made, into which an angle-iron could be placed to bracket ("bench") a leveling rod, thus ensuring that the leveling rod can be repositioned in exactly the same place in the future. A benchmark in computer terms is the result of running a computer program, or a set of programs, in order to assess the relative performance of an object by running a number of standard tests and trials against it. This paper will discuss the history of simulation benchmarks that are being used by multiple branches of the military and agencies of the US government. These benchmarks range from missile defense applications to chemical biological situations. Typically, a benchmark is used with Monte Carlo runs in order to tease out how algorithms deal with variability and the range of possible inputs. We will also describe problems that can be solved by a benchmark.

Dunham, Darin T.; West, Philip D.

2011-09-01

83

Intercomparison of the finite difference and nodal discrete ordinates and surface flux transport methods for a LWR pool-reactor benchmark problem in X-Y geometry  

SciTech Connect

The aim of the present work is to compare and discuss the three of the most advanced two dimensional transport methods, the finite difference and nodal discrete ordinates and surface flux method, incorporated into the transport codes TWODANT, TWOTRAN-NODAL, MULTIMEDIUM and SURCU. For intercomparison the eigenvalue and the neutron flux distribution are calculated using these codes in the LWR pool reactor benchmark problem. Additionally the results are compared with some results obtained by French collision probability transport codes MARSYAS and TRIDENT. Because the transport solution of this benchmark problem is close to its diffusion solution some results obtained by the finite element diffusion code FINELM and the finite difference diffusion code DIFF-2D are included.

O'Dell, R.D.; Stepanek, J.; Wagner, M.R.

1983-01-01

84

NAS parallel benchmark results  

NASA Technical Reports Server (NTRS)

The NAS (Numerical Aerodynamic Simulation) parallel benchmarks have been developed at NASA Ames Research Center to study the performance of parallel supercomputers. The eight benchmark problems are specified in a 'pencil and paper' fashion. The performance results of various systems using the NAS parallel benchmarks are presented. These results represent the best results that have been reported to the authors for the specific systems listed. They represent implementation efforts performed by personnel in both the NAS Applied Research Branch of NASA Ames Research Center and in other organizations.

Bailey, D. H.; Barszcz, E.; Dagum, L.; Simon, H. D.

1992-01-01

85

Heat pipe investigations  

NASA Technical Reports Server (NTRS)

The OAO-C spacecraft has three circular heat pipes, each of a different internal design, located in the space between the spacecraft structural tube and the experiment tube, which are designed to isothermalize the structure. Two of the pipes are used to transport high heat loads, and the third is for low heat loads. The test problems deal with the charging of the pipes, modifications, the mobile tilt table, the position indicator, and the heat input mechanisms. The final results showed that the techniques used were adequate for thermal-vacuum testing of heat pipes.

Marshburn, J. P.

1972-01-01

86

Preventing and Thawing Frozen Pipes  

MedlinePLUS

... do freeze. Why Pipe Freezing is a Problem Water has a unique property in that it expands as it freezes. This expansion puts tremendous pressure on whatever is containing it, including ... a container, expanding water can cause pipes to break. Pipes that freeze ...

87

DRAINAGE PIPE DETECTOR  

Technology Transfer Automated Retrieval System (TEKTRAN)

One of the more frustrating problems confronting farmers and land improvement contractors in the Midwestern United States involves locating buried agricultural drainage pipes. Conventional geophysical methods, particularly ground penetrating radar (GPR), presently being used for environmental and co...

88

Comparison of Whole-Domain and Sequential Algorithms for Function Specification Method in the Inverse Heat Transfer Problem of Laminar Convective Pipe Flow  

Microsoft Academic Search

This article compares the application of the whole-domain function specification method (WDFSM) and the sequential function specification method (SFSM) to the inverse problem of transient conjugate heat transfer of laminar forced convection in a circular pipe. The two inverse methods are used to estimate the time-varying inlet temperature and the outer-wall heat flux simultaneously on the basis of temperature measurements

Cha'o.-Kuang Chen; Li-Wen Wu; Yue-Tzu Yang

2006-01-01

89

High temperature heat pipe experiments aboard the space shuttle  

Microsoft Academic Search

Although high temperature, liquid metal heat pipe radiators have become a standard component on most space nuclear power systems, there is no experimental data on the operation of these heat pipes in a zero gravity or micro gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation. Three SST\\/potassium

Keith A. Woloshun; Michael A. Merrigan; J. Tom Sena; Joseph Secary Capt

1993-01-01

90

High temperature heat pipe experiments in low earth orbit  

Microsoft Academic Search

Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for

K. Woloshun; M. A. Merrigan; J. T. Sena; E. Critchley

1993-01-01

91

Comet whole-core solution to a stylized 3-dimensional pressurized water reactor benchmark problem with UO{sub 2}and MOX fuel  

SciTech Connect

A stylized pressurized water reactor (PWR) benchmark problem with UO{sub 2} and MOX fuel was used to test the accuracy and efficiency of the coarse mesh radiation transport (COMET) code. The benchmark problem contains 125 fuel assemblies and 44,000 fuel pins. The COMET code was used to compute the core eigenvalue and assembly and pin power distributions for three core configurations. In these calculations, a set of tensor products of orthogonal polynomials were used to expand the neutron angular phase space distribution on the interfaces between coarse meshes. The COMET calculations were compared with the Monte Carlo code MCNP reference solutions using a recently published an 8-group material cross section library. The comparison showed both the core eigenvalues and assembly and pin power distributions predicated by COMET agree very well with the MCNP reference solution if the orders of the angular flux expansion in the two spatial variables and the polar and azimuth angles on the mesh boundaries are 4, 4, 2 and 2. The mean and maximum differences in the pin fission density distribution ranged from 0.28%-0.44% and 3.0%-5.5%, all within 3-sigma uncertainty of the MCNP solution. These comparisons indicate that COMET can achieve accuracy comparable to Monte Carlo. It was also found that COMET's computational speed is 450 times faster than MCNP. (authors)

Zhang, D.; Rahnema, F. [Georgia Inst. of Technology, 770 State Street, Atlanta, GA 30332-0745 (United States)

2012-07-01

92

The SEQUOIA 2000 storage benchmark  

Microsoft Academic Search

This paper presents a benchmark that concisely captures the data base requirements of a collection of Earth Scientists working in the SEQUOIA 2000 project on various aspects of global change research. This benchmark has the novel characteristic that it uses real data sets and real queries that are representative of Earth Science tasks. Because it appears that Earth Science problems

Michael Stonebraker; Jim Frew; Kenn Gardels; Jeff Meredith

1993-01-01

93

Benchmarking B-cell epitope prediction for the design of peptide-based vaccines: problems and prospects.  

PubMed

To better support the design of peptide-based vaccines, refinement of methods to predict B-cell epitopes necessitates meaningful benchmarking against empirical data on the cross-reactivity of polyclonal antipeptide antibodies with proteins, such that the positive data reflect functionally relevant cross-reactivity (which is consistent with antibody-mediated change in protein function) and the negative data reflect genuine absence of cross-reactivity (rather than apparent absence of cross-reactivity due to artifactual masking of B-cell epitopes in immunoassays). These data are heterogeneous in view of multiple factors that complicate B-cell epitope prediction, notably physicochemical factors that define key structural differences between immunizing peptides and their cognate proteins (e.g., unmatched electrical charges along the peptide-protein sequence alignments). If the data are partitioned with respect to these factors, iterative parallel benchmarking against the resulting subsets of data provides a basis for systematically identifying and addressing the limitations of methods for B-cell epitope prediction as applied to vaccine design. PMID:20368996

Caoili, Salvador Eugenio C

2010-01-01

94

Testing (Validating?) Cross Sections with ICSBEP Benchmarks  

SciTech Connect

We discuss how to use critical benchmarks from the International Handbook of Evaluated Criticality Safety Benchmark Experiments to determine the applicability of specific cross sections to the end-user's problem of interest. Particular attention is paid to making sure the selected suite of benchmarks includes the user's range of applicability (ROA).

Kahler, Albert C. III [Los Alamos National Laboratory

2012-06-28

95

An investigation of the origin of Rock City and cause of piping problems at Mountain Lake, Giles County, Virginia  

NASA Astrophysics Data System (ADS)

Mountain Lake is one of only two natural lakes in the state of Virginia. The lake's origin has been attributed to either a natural solution-collapse basin, or to a landslide damming the valley of northwesterly flowing Pond Drain, or to a NW-SE trending fracture lineation. The lake is located within the breached northwest limb of a gently plunging anticline, a part of the larger Valley and Ridge physiographic province. In recent years, the lake drained almost completely, exposing the lake bottom and revealing the presence of four sinkhole-like depressions, containing piping holes at their sides and bottoms, at the northeastern and northwestern margins of the lake. This study focuses on the most likely origin of large sandstone blocks present at the northern end of the lake in an area locally referred to as "Rock City", including mapping of the block locations and analyzing the mode and extent of displacement that they have undergone. An additional objective is to investigate the piping potential of the lake-bottom sediment and its role in seepage out of the lake basin causing lake-level fluctuations. Mapping of Rock City was conducted by taking GPS readings at the corners of the rock blocks and using ArcMap Software. Investigations of the displacement mode of the rock blocks was done by comparing the measured orientations of principal discontinuity sets, forming the rock-block boundaries, with discontinuity orientations of undisturbed outcrops within the headscarp, using stereonet analysis. Grain size analysis, Atterberg limits, and a compaction-mold permeameter test were used to evaluate lake sediment's susceptibility to piping. Field observations and discontinuity data analysis indicate that Rock City is a landslide that dammed the valley of Pond Drain, consequently forming the lake. The primary mode of slope movement involves lateral spreading that is associated with extension occurring along discontinuities. The Tuscarora Sandstone rock blocks comprising Rock City were detached from the scarp face along a northwest-southeast trending joint set and were displaced laterally towards the west. A seismic event appears to be the most likely triggering mechanism for slope movement. Laboratory testing reveals that lake-bottom sediment is susceptible to piping, which is the primary mechanism responsible for the formation of the lake-bed depressions and lake-levels fluctuations. Grain size analysis reveals that lake-bottom sediment consists predominantly of fine sand and silt, both of which are highly susceptible to piping. Results of the compaction-mold permeameter test show that the hydraulic gradient at which lake-bottom sediment starts to pipe, the critical hydraulic gradient, ranges between 1 and 10, depending on the density, grain size distribution and cohesive properties of the sediment.

Atallah, Nidal Walid

96

Applications of the Space-Time Conservation Element and Solution Element (CE/SE) Method to Computational Aeroacoustic Benchmark Problems  

NASA Technical Reports Server (NTRS)

The Internal Propagation problems, Fan Noise problem, and Turbomachinery Noise problems are solved using the space-time conservation element and solution element (CE/SE) method. The problems in internal propagation problems address the propagation of sound waves through a nozzle. Both the nonlinear and linear quasi 1D Euler equations are solved. Numerical solutions are presented and compared with the analytical solution. The fan noise problem concerns the effect of the sweep angle on the acoustic field generated by the interaction of a convected gust with a cascade of 3D flat plates. A parallel version of the 3D CE/SE Euler solver is developed and employed to obtain numerical solutions for a family of swept flat plates. Numerical solutions for sweep angles of 0, 5, 10, and 15 deg are presented. The turbomachinery problems describe the interaction of a 2D vortical gust with a cascade of flat-plate airfoils with/without a downstream moving grid. The 2D nonlinear Euler Equations are solved and the converged numerical solutions are presented and compared with the corresponding analytical solution. All the comparisons demonstrate that the CE/SE method is capable of solving aeroacoustic problems with/without shock waves in a simple and efficient manner. Furthermore, the simple non-reflecting boundary condition used in the CE/SE method which is not based on the characteristic theory works very well in 1D, 2D and 3D problems.

Wang, Xiao-Yen; Himansu, Ananda; Chang, Sin-Chung; Jorgenson, Philip C. E.

2000-01-01

97

A stabilized mixed finite element method for shear-rate dependent non-Newtonian fluids: 3D benchmark problems and application to blood flow in bifurcating arteries  

NASA Astrophysics Data System (ADS)

This paper presents a stabilized mixed finite element method for shear-rate dependent fluids. The nonlinear viscosity field is a function of the shear-rate and varies uniformly in space and in time. The stabilized form is developed via application of Variational Multiscale (VMS) framework to the underlying generalized Navier-Stokes equation. Linear and quadratic tetrahedral and hexahedral elements are employed with equal-order interpolations for the velocity and pressure fields. A variety of benchmark problems are solved to assess the stability and accuracy properties of the resulting method. The method is then applied to non-Newtonian shear-rate dependent flows in bifurcating artery geometry, and significant non-Newtonian fluid effects are observed. A comparative study of the proposed method shows that the additional computational costs due to the nonlinear shear-rate dependent viscosity are only ten percent more than the computational cost for a Newtonian model.

Kwack, JaeHyuk; Masud, Arif

2014-04-01

98

Heat Pipes  

NASA Technical Reports Server (NTRS)

Phoenix Refrigeration Systems, Inc.'s heat pipe addition to the Phoenix 2000, a supermarket rooftop refrigeration/air conditioning system, resulted from the company's participation in a field test of heat pipes. Originally developed by NASA to control temperatures in space electronic systems, the heat pipe is a simple, effective, heat transfer system. It has been used successfully in candy storage facilities where it has provided significant energy savings. Additional data is expected to fully quantify the impact of the heat pipes on supermarket air conditioning systems.

1991-01-01

99

NAS Parallel Benchmarks Results  

NASA Technical Reports Server (NTRS)

The NAS Parallel Benchmarks (NPB) were developed in 1991 at NASA Ames Research Center to study the performance of parallel supercomputers. The eight benchmark problems are specified in a pencil and paper fashion i.e. the complete details of the problem to be solved are given in a technical document, and except for a few restrictions, benchmarkers are free to select the language constructs and implementation techniques best suited for a particular system. In this paper, we present new NPB performance results for the following systems: (a) Parallel-Vector Processors: Cray C90, Cray T'90 and Fujitsu VPP500; (b) Highly Parallel Processors: Cray T3D, IBM SP2 and IBM SP-TN2 (Thin Nodes 2); (c) Symmetric Multiprocessing Processors: Convex Exemplar SPP1000, Cray J90, DEC Alpha Server 8400 5/300, and SGI Power Challenge XL. We also present sustained performance per dollar for Class B LU, SP and BT benchmarks. We also mention NAS future plans of NPB.

Subhash, Saini; Bailey, David H.; Lasinski, T. A. (Technical Monitor)

1995-01-01

100

Piping Plover  

USGS Multimedia Gallery

Chicks and eggs of piping plovers. The piping plover is a small migratory shorebird listed as endangered in Canada and the U.S. Great Lakes, and threatened throughout the remainder of its U.S. breeding and winter range. Recent surveys indicate that there are only about 8,000 adults in existence.  Th...

2010-02-24

101

Piping Plover  

USGS Multimedia Gallery

An adult piping plover. The piping plover is a small migratory shorebird listed as endangered in Canada and the U.S. Great Lakes, and threatened throughout the remainder of its U.S. breeding and winter range. Recent surveys indicate that there are only about 8,000 adults in existence. The USGS is co...

2010-02-24

102

The DaCapo benchmarks: java benchmarking development and analysis  

Microsoft Academic Search

Since benchmarks drive computer science research and industry product development, which ones we use and how we evaluate them are key questions for the community. Despite complex run-time tradeoffs due to dynamic compilation and garbage collection required for Java programs, many evaluations still use methodolo-gies developed for C, C++, and Fortran. SPEC, the dominant pur-veyor of benchmarks, compounded this problem

Stephen M. Blackburn; Robin Garner; Chris Hoffmann; Asjad M. Khan; Kathryn S. Mckinley; Rotem Bentzur; Amer Diwan; Daniel Feinberg; Daniel Frampton; Samuel Z. Guyer; Martin Hirzel; Antony L. Hosking; Maria Jump; Han Bok Lee; J. Eliot B. Moss; Aashish Phansalkar; Darko Stefanovic; Thomas Vandrunen; Daniel Von Dincklage; Ben Wiedermann

2006-01-01

103

Interpolation and extrapolation problems of multivariate regression in analytical chemistry: benchmarking the robustness on near-infrared (NIR) spectroscopy data.  

PubMed

Modern analytical chemistry of industrial products is in need of rapid, robust, and cheap analytical methods to continuously monitor product quality parameters. For this reason, spectroscopic methods are often used to control the quality of industrial products in an on-line/in-line regime. Vibrational spectroscopy, including mid-infrared (MIR), Raman, and near-infrared (NIR), is one of the best ways to obtain information about the chemical structures and the quality coefficients of multicomponent mixtures. Together with chemometric algorithms and multivariate data analysis (MDA) methods, which were especially created for the analysis of complicated, noisy, and overlapping signals, NIR spectroscopy shows great results in terms of its accuracy, including classical prediction error, RMSEP. However, it is unclear whether the combined NIR + MDA methods are capable of dealing with much more complex interpolation or extrapolation problems that are inevitably present in real-world applications. In the current study, we try to make a rather general comparison of linear, such as partial least squares or projection to latent structures (PLS); "quasi-nonlinear", such as the polynomial version of PLS (Poly-PLS); and intrinsically non-linear, such as artificial neural networks (ANNs), support vector regression (SVR), and least-squares support vector machines (LS-SVM/LSSVM), regression methods in terms of their robustness. As a measure of robustness, we will try to estimate their accuracy when solving interpolation and extrapolation problems. Petroleum and biofuel (biodiesel) systems were chosen as representative examples of real-world samples. Six very different chemical systems that differed in complexity, composition, structure, and properties were studied; these systems were gasoline, ethanol-gasoline biofuel, diesel fuel, aromatic solutions of petroleum macromolecules, petroleum resins in benzene, and biodiesel. Eighteen different sample sets were used in total. General conclusions are made about the applicability of ANN- and SVM-based regression tools in the modern analytical chemistry. The effectiveness of different multivariate algorithms is different when going from classical accuracy to robustness. Neural networks, which are capable of producing very accurate results with respect to classical RMSEP, are not able to solve interpolation problems or, especially, extrapolation problems. The chemometric methods that are based on the support vector machine (SVM) ideology are capable of solving both classical regression and interpolation/extrapolation tasks. PMID:22337290

Balabin, Roman M; Smirnov, Sergey V

2012-04-01

104

High temperature heat pipe experiments aboard the space shuttle  

SciTech Connect

Although high temperature, liquid metal heat pipe radiators have become a standard component on most space nuclear power systems, there is no experimental data on the operation of these heat pipes in a zero gravity or micro gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation. Three SST/potassium heat pipes are being designed, fabricated, and ground tested. It is anticipated that these heat pipes will fly aboard the space shuttle in 1995. Three wick structures will be tested: homogeneous, arterial, and annular gap. Ground tests are described that simulate the space shuttle environment in every way except gravity field.

Woloshun, K.A.; Merrigan, M.A.; Sena, J.T. (Los Alamos National Laboratory, P.O. Box 1663, Mail Stop J576, Los Alamos, New Mexico 87545 (United States)); Secary, C.J. (PL/VTPT, Kirtland AFB, Albuquerque, New Mexico 87117 (United States))

1993-01-10

105

Light pipes for LED measurements  

NASA Technical Reports Server (NTRS)

Light pipe directly couples LED optical output to single detector. Small area detector measures total optical output of diode. Technique eliminates thermal measurement problems and channels optical output to remote detector.

Floyd, S. R.; Thomas, E. F., Jr.

1976-01-01

106

High temperature heat pipe experiments in low earth orbit  

SciTech Connect

Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for testing in low earth orbit. It is anticipated that these heat pipes will be tested aborad the Space Shuttle in 1995. Three heat pipes will be tested in a cargo bay Get Away Special (GAS) canister. The heat pipes are SST/potassium, each with a different wick structure; homogeneous, arterial, and annular gap, the heat pipes have been designed, fabricated, and ground tested. In this paper, the heat pipe designs are specified, and transient and steady-state ground test data are presented.

Woloshun, K.; Merrigan, M.A.; Sena, J.T. (Los Alamos National Lab., NM (United States)); Critchley, E. (Phillips Lab., Kirtland AFB, NM (United States))

1993-01-01

107

High temperature heat pipe experiments in low earth orbit  

SciTech Connect

Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for testing in low earth orbit. It is anticipated that these heat pipes will be tested aborad the Space Shuttle in 1995. Three heat pipes will be tested in a cargo bay Get Away Special (GAS) canister. The heat pipes are SST/potassium, each with a different wick structure; homogeneous, arterial, and annular gap, the heat pipes have been designed, fabricated, and ground tested. In this paper, the heat pipe designs are specified, and transient and steady-state ground test data are presented.

Woloshun, K.; Merrigan, M.A.; Sena, J.T. [Los Alamos National Lab., NM (United States); Critchley, E. [Phillips Lab., Kirtland AFB, NM (United States)

1993-02-01

108

Large-bore pipe decontamination  

SciTech Connect

The decontamination and decommissioning (D and D) of 1200 buildings within the US Department of Energy-Office of Environmental Management (DOE-EM) Complex will require the disposition of miles of pipe. The disposition of large-bore pipe, in particular, presents difficulties in the area of decontamination and characterization. The pipe is potentially contaminated internally as well as externally. This situation requires a system capable of decontaminating and characterizing both the inside and outside of the pipe. Current decontamination and characterization systems are not designed for application to this geometry, making the direct disposal of piping systems necessary in many cases. The pipe often creates voids in the disposal cell, which requires the pipe to be cut in half or filled with a grout material. These methods are labor intensive and costly to perform on large volumes of pipe. Direct disposal does not take advantage of recycling, which could provide monetary dividends. To facilitate the decontamination and characterization of large-bore piping and thereby reduce the volume of piping required for disposal, a detailed analysis will be conducted to document the pipe remediation problem set; determine potential technologies to solve this remediation problem set; design and laboratory test potential decontamination and characterization technologies; fabricate a prototype system; provide a cost-benefit analysis of the proposed system; and transfer the technology to industry. This report summarizes the activities performed during fiscal year 1997 and describes the planned activities for fiscal year 1998. Accomplishments for FY97 include the development of the applicable and relevant and appropriate regulations, the screening of decontamination and characterization technologies, and the selection and initial design of the decontamination system.

Ebadian, M.A.

1998-01-01

109

Unstructured Adaptive (UA) NAS Parallel Benchmark, Version 1.0  

Microsoft Academic Search

We present a complete specification of a new benchmark for measuring the perfor- mance of modern computer systems when solving scientific problems featuring irregular, dynamic memory accesses. It complements the existing NAS Parallel Benchmark suite. The benchmark involves the solution of a stylized heat transfer problem in a cubic domain, discretized on an adaptively refined, unstructured mesh.

Huiyu Feng; Rob F. Van der Wijngaart; Rupak Biswas; Catherine Mavriplis

2004-01-01

110

Unstructured Adaptive (UA) NAS Parallel Benchmark. Version 1.0  

NASA Technical Reports Server (NTRS)

We present a complete specification of a new benchmark for measuring the performance of modern computer systems when solving scientific problems featuring irregular, dynamic memory accesses. It complements the existing NAS Parallel Benchmark suite. The benchmark involves the solution of a stylized heat transfer problem in a cubic domain, discretized on an adaptively refined, unstructured mesh.

Feng, Huiyu; VanderWijngaart, Rob; Biswas, Rupak; Mavriplis, Catherine

2004-01-01

111

BENCHMARKING PARALLEL MACHINES VIA A SOFTWARE ARCHITECTURE Srikanth Kambhatla, Jon Inouye, Jonathan Walpole  

E-print Network

BENCHMARKING PARALLEL MACHINES VIA A SOFTWARE ARCHITECTURE Srikanth Kambhatla, Jon Inouye, Jonathan, Parallel Processing, Software Architecture, Synthetic Benchmark, Linda] ABSTRACT The diversity in parallel architectures and the programming styles induced thereof, make benchmarking of parallel machines a hard problem

Walpole, Jonathan

112

Heat Pipes  

NASA Technical Reports Server (NTRS)

Bobs Candies, Inc. produces some 24 million pounds of candy a year, much of it 'Christmas candy.' To meet Christmas demand, it must produce year-round. Thousands of cases of candy must be stored a good part of the year in two huge warehouses. The candy is very sensitive to temperature. The warehouses must be maintained at temperatures of 78-80 degrees Fahrenheit with relative humidities of 38- 42 percent. Such precise climate control of enormous buildings can be very expensive. In 1985, energy costs for the single warehouse ran to more than $57,000 for the year. NASA and the Florida Solar Energy Center (FSEC) were adapting heat pipe technology to control humidity in building environments. The heat pipes handle the jobs of precooling and reheating without using energy. The company contacted a FSEC systems engineer and from that contact eventually emerged a cooperative test project to install a heat pipe system at Bobs' warehouses, operate it for a period of time to determine accurately the cost benefits, and gather data applicable to development of future heat pipe systems. Installation was completed in mid-1987 and data collection is still in progress. In 1989, total energy cost for two warehouses, with the heat pipes complementing the air conditioning system was $28,706, and that figures out to a cost reduction.

1990-01-01

113

Silicate globules in kyanite from grospydites of the Zagadochnaya kimberlite pipe, Yakutia: The problem of the origin  

NASA Astrophysics Data System (ADS)

The results of complex study of silicate globules and ?-quartz paramorphs after coesite in kyanite from grospydites from the Zagadochnaya kimberlite pipe, Yakutia, using optical and scanning electron spectroscopy, electron and ion microprobes, LA ICP MS and Raman spectroscopy, are presented. The existence of radial fractures diverging from silicate globules into the matrix (kyanite) attests to the fact that the content of the globules is extremely condensed. A zonal structure is usually typical for globules: a coat and a core, which can be explicitly distinguished under the electron microscope, can be differentiated in them. Compositionally, the coat of the globule corresponds to potassium feldspar (wt %: 66.4 SiO2; 16.9 Al2O3; 0.4 FeO; 0.1 CaO; 0.2 Na2O; 14.7 K2O). The globules were also detected in which along with K, a high content of Na and Ca was also ascertained in the silicate coat. The globule coat is considerably enriched with Ba, La, Ce, Nb, and a number of other noncompatible elements as compared with xenolith minerals. The water content in globules is ˜0.6 wt %. As compared with the host mineral (kyanite), the core part of the globules is also enriched with Co, Ni, Zn, and Cu; their content in kyanite is negligibly low. The entire data collection attests to the fact that the formation of silicate globules could have been caused by interaction of the conservated fluid and/or water-silicate melt with the host mineral and crystalline inclusions of clinopyroxene and garnet with decreasing pressure during the transportation of grospydite xenoliths by the kimberlite melt to the Earth's surface.

Tomilenko, A. A.; Kovyazin, S. V.; Pokhilenko, L. N.; Sobolev, N. V.

2011-01-01

114

The NAS Parallel Benchmark Kernels in MPL  

Microsoft Academic Search

The Numerical Aerodynamic Simulation (NAS) Parallel Benchmarks are a set ofalgorithmically specified benchmarks indicative of the computation and communicationneeds of typical large-scale aerodynamics problems. Although a greatdeal of work has been done with respect to implementing the NAS ParallelBenchmark suite on high-end vector supercomputers, multiprocessors, and multicomputers,only recently has the possibility of running such demanding applicationson workstation clusters begun to

Adam Ferrari; Adrian Filipi-martin; Soumya Viswanathan

1995-01-01

115

CFD validation in OECD/NEA t-junction benchmark.  

SciTech Connect

When streams of rapidly moving flow merge in a T-junction, the potential arises for large oscillations at the scale of the diameter, D, with a period scaling as O(D/U), where U is the characteristic flow velocity. If the streams are of different temperatures, the oscillations result in experimental fluctuations (thermal striping) at the pipe wall in the outlet branch that can accelerate thermal-mechanical fatigue and ultimately cause pipe failure. The importance of this phenomenon has prompted the nuclear energy modeling and simulation community to establish a benchmark to test the ability of computational fluid dynamics (CFD) codes to predict thermal striping. The benchmark is based on thermal and velocity data measured in an experiment designed specifically for this purpose. Thermal striping is intrinsically unsteady and hence not accessible to steady state simulation approaches such as steady state Reynolds-averaged Navier-Stokes (RANS) models.1 Consequently, one must consider either unsteady RANS or large eddy simulation (LES). This report compares the results for three LES codes: Nek5000, developed at Argonne National Laboratory (USA), and Cabaret and Conv3D, developed at the Moscow Institute of Nuclear Energy Safety at (IBRAE) in Russia. Nek5000 is based on the spectral element method (SEM), which is a high-order weighted residual technique that combines the geometric flexibility of the finite element method (FEM) with the tensor-product efficiencies of spectral methods. Cabaret is a 'compact accurately boundary-adjusting high-resolution technique' for fluid dynamics simulation. The method is second-order accurate on nonuniform grids in space and time, and has a small dispersion error and computational stencil defined within one space-time cell. The scheme is equipped with a conservative nonlinear correction procedure based on the maximum principle. CONV3D is based on the immersed boundary method and is validated on a wide set of the experimental and benchmark data. The numerical scheme has a very small scheme diffusion and is the second and the first order accurate in space and time, correspondingly. We compare and contrast simulation results for three computational fluid dynamics codes CABARET, Conv3D, and Nek5000 for the T-junction thermal striping problem that was the focus of a recent OECD/NEA blind benchmark. The corresponding codes utilize finite-difference implicit large eddy simulation (ILES), finite-volume LES on fully staggered grids, and an LES spectral element method (SEM), respectively. The simulations results are in a good agreement with experimenatl data. We present results from a study of sensitivity to computational mesh and time integration interval, and discuss the next steps in the simulation of this problem.

Obabko, A. V.; Fischer, P. F.; Tautges, T. J.; Karabasov, S.; Goloviznin, V. M.; Zaytsev, M. A.; Chudanov, V. V.; Pervichko, V. A.; Aksenova, A. E. (Mathematics and Computer Science); (Cambridge Univ.); (Moscow Institute of Nuclar Energy Safety)

2011-08-23

116

Radiation Detection Computational Benchmark Scenarios  

SciTech Connect

Modeling forms an important component of radiation detection development, allowing for testing of new detector designs, evaluation of existing equipment against a wide variety of potential threat sources, and assessing operation performance of radiation detection systems. This can, however, result in large and complex scenarios which are time consuming to model. A variety of approaches to radiation transport modeling exist with complementary strengths and weaknesses for different problems. This variety of approaches, and the development of promising new tools (such as ORNL’s ADVANTG) which combine benefits of multiple approaches, illustrates the need for a means of evaluating or comparing different techniques for radiation detection problems. This report presents a set of 9 benchmark problems for comparing different types of radiation transport calculations, identifying appropriate tools for classes of problems, and testing and guiding the development of new methods. The benchmarks were drawn primarily from existing or previous calculations with a preference for scenarios which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22. From a technical perspective, the benchmarks were chosen to span a range of difficulty and to include gamma transport, neutron transport, or both and represent different important physical processes and a range of sensitivity to angular or energy fidelity. Following benchmark identification, existing information about geometry, measurements, and previous calculations were assembled. Monte Carlo results (MCNP decks) were reviewed or created and re-run in order to attain accurate computational times and to verify agreement with experimental data, when present. Benchmark information was then conveyed to ORNL in order to guide testing and development of hybrid calculations. The results of those ADVANTG calculations were then sent to PNNL for compilation. This is a report describing the details of the selected Benchmarks and results from various transport codes.

Shaver, Mark W.; Casella, Andrew M.; Wittman, Richard S.; McDonald, Ben S.

2013-09-24

117

Whistling of a pipe system with multiple side branches: Comparison with corrugated pipes  

Microsoft Academic Search

Corrugated pipes are widely used because they combine local rigidity with global flexibility. Whistling induced by flow through such pipes can lead to serious environmental and structural problems. The whistling of a multiple side branch system is compared to the whistling behavior of corrugated pipes. The study has been restricted to cavities with sharp edges which are convenient for theoretical

D. Tonon; B. J. T. Landry; S. P. C. Belfroid; J. F. H. Willems; G. C. J. Hofmans; A. Hirschberg

2010-01-01

118

Sequential Circuit Test Generator (STG) benchmark results  

Microsoft Academic Search

The authors report on the results of running a version of the Sequential Circuit Test Generator (STG3) on the ISCAS-89 sequential circuit benchmarks. First, they present a brief history of STG and briefly describe the algorithms used. They then describe the conditions under which the experiments were run and give the benchmark results. No particular problems were encountered when running

W.-T. Cheng; S. Davidson

1989-01-01

119

Evaluation of high-energy pipe rupture experiments: Final report  

SciTech Connect

Fracture mechanics and thermal hydraulic evaluations of the EPRI high energy pipe rupture experiments have been carried out. The purpose of these evaluations was to benchmark analytical methods with prototypical pipe leak and rupture behavior. Fracture mechanics predictions were made using methods and materials property data available in the literature. Conditions which were predicted to produce a pipe leak did result in a leak while conditions expected to result in pipe rupture did rupture. Further, system blowdown following breaching of the pipe wall does not appear to influence the pipe leak or rupture behavior except for long axial defects. The thermal hydraulic behavior of the EPRI high energy pipe tests was typical of system blowdowns from an initial subcooled condition. Predictions of vessel depressurization, discharge flow rate from the final crack opening area, and blowdown thrust forces are consistent with observations. 22 refs., 18 figs., 12 tabs.

Gerber, T.L.; Kuo, A.Y.; Copeland, J.F.; Abdollahian, D.

1988-01-01

120

Heat Pipe Systems  

NASA Technical Reports Server (NTRS)

Solar Fundamentals, Inc.'s hot water system employs space-derived heat pipe technology. It is used by a meat packing plant to heat water for cleaning processing machinery. Unit is complete system with water heater, hot water storage, electrical controls and auxiliary components. Other than fans and a circulating pump, there are no moving parts. System's unique design eliminates problems of balancing, leaking, corroding, and freezing.

1988-01-01

121

The NAS parallel benchmarks  

NASA Technical Reports Server (NTRS)

A new set of benchmarks has been developed for the performance evaluation of highly parallel supercomputers in the framework of the NASA Ames Numerical Aerodynamic Simulation (NAS) Program. These consist of five 'parallel kernel' benchmarks and three 'simulated application' benchmarks. Together they mimic the computation and data movement characteristics of large-scale computational fluid dynamics applications. The principal distinguishing feature of these benchmarks is their 'pencil and paper' specification-all details of these benchmarks are specified only algorithmically. In this way many of the difficulties associated with conventional benchmarking approaches on highly parallel systems are avoided.

Bailey, D. H.; Barszcz, E.; Barton, J. T.; Carter, R. L.; Lasinski, T. A.; Browning, D. S.; Dagum, L.; Fatoohi, R. A.; Frederickson, P. O.; Schreiber, R. S.

1991-01-01

122

The NAS parallel benchmarks  

NASA Technical Reports Server (NTRS)

A new set of benchmarks was developed for the performance evaluation of highly parallel supercomputers. These benchmarks consist of a set of kernels, the 'Parallel Kernels,' and a simulated application benchmark. Together they mimic the computation and data movement characteristics of large scale computational fluid dynamics (CFD) applications. The principal distinguishing feature of these benchmarks is their 'pencil and paper' specification - all details of these benchmarks are specified only algorithmically. In this way many of the difficulties associated with conventional benchmarking approaches on highly parallel systems are avoided.

Bailey, David (editor); Barton, John (editor); Lasinski, Thomas (editor); Simon, Horst (editor)

1993-01-01

123

Heat pipe technology  

NASA Technical Reports Server (NTRS)

A bibliography of heat pipe technology to provide a summary of research projects conducted on heat pipes is presented. The subjects duscussed are: (1) heat pipe applications, (2) heat pipe theory, (3) design and fabrication, (4) testing and operation, (5) subject and author index, and (6) heat pipe related patents.

1972-01-01

124

Measuring and modelling sewer pipes from video  

Microsoft Academic Search

This article presents a system for the automatic measurement and modelling of sewer pipes. The system recovers the interior shape of a sewer pipe from a video sequence which is acquired by a sh-e ye lens camera moving inside the pipe. The approach is based on tracking interest points across successive video frames and posing the general structure-from-motion problem. It

Juho Kannala; Sami S. Brandt; Janne Heikkilä

2008-01-01

125

Benchmarking for Higher Education.  

ERIC Educational Resources Information Center

The chapters in this collection explore the concept of benchmarking as it is being used and developed in higher education (HE). Case studies and reviews show how universities in the United Kingdom are using benchmarking to aid in self-regulation and self-improvement. The chapters are: (1) "Introduction to Benchmarking" (Norman Jackson and Helen…

Jackson, Norman, Ed.; Lund, Helen, Ed.

126

Steam bubble collapse, water hammer and piping network response. Volume I. Steam bubble collapse and water hammer in piping systems: experiments and analysis. Final report  

SciTech Connect

Water hammer incidents in conventional and nuclear steam systems are an important problem of broad general interest in piping network design and transient operation. Water hammer in PWR steam generator sparger feed lines has, for example, been a recurrent problem when the sparger becomes uncovered during certain operational transients (Creare 1977). The central goal of this research has been to develop experimental data and supporting analyses that will contribute to the evolving understanding of water hammer created by steam bubble entrapment in a pipe containing subcooled liquid. The first objective of this study has been to obtain a body of experimental data on water hammer initiated by steam bubble collapse. These experiments include measurement of pressure transients and high speed films of the process of bubble collapse and impact, and, in conjunction with Hurwitz (1980), records of the resultant pressure wave propagation through a variety of simple piping configurations and measurements of the induced structural response. The data that have been obtained should be useful in benchmarking existing analytic models and numerical codes.

Gruel, R.; Hurwitz, W.; Huber, P.; Griffith, P.

1980-06-01

127

Benchmarking your benchmarks: a user's perspective  

SciTech Connect

This paper is intended for anyone faced with the responsibility for computer hardware or software selection. The content is biased toward administrative considerations, although some technical issues are presented. The basic goal is to promote a role for benchmarking in the computer acquisition process that is significantly broader than that commonly employed. We attempt to do this by showing how a thorough benchmarking effort (in the usual sense) did not provide sufficient information to accurately predict user satisfaction and productivity. We describe other measures of a system's properties that should be included in benchmarking.

Brice, R.

1982-01-01

128

The feasibility of electrohydrodynamic heat pipes  

NASA Technical Reports Server (NTRS)

The effect of a nonuniform electrostatic field on insulating dielectric liquids in heat pipes was studied. Topics discussed include the theory of operation, design criteria, and evaluation of optimal design features. It is concluded that the electrodynamic heat pipes offer advantages that must be weighed against the disadvantages in order to arrive at a proper assessment of their value in solving heat transfer problems.

Jones, T. B.

1971-01-01

129

Heat Pipe Precools and Reheats Dehumidified Air  

NASA Technical Reports Server (NTRS)

Precooling and reheating by heat pipe reduces operating costs of air-conditioning. Warm air returned from air-conditioned space and cooled air supplied are precooled and reheated, respectively, by each other through a heat pipe. Heat-pipe technology brought to bear on problem of conserving airconditioning energy in hot, humid environments. Any increase in the cost of equipment due to installation of heat-pipe heat exchangers expected to be recovered in energy savings during service period of 2 years or less.

Koning, R. C.; Boggs, W. H.; Barnett, U. R.; Dinh, K.

1986-01-01

130

Flow conditions of fresh mortar and concrete in different pipes  

SciTech Connect

The variation in fresh concrete flow rate over the pipe cross section was investigated on differently coloured and highly flowable concrete mixes flowing through pipes of different materials (rubber, steel, acryl). First, uncoloured (gray) concrete was poured through the pipe and the pipe blocked. Similar but coloured (black) concrete was then poured into the pipe filled with gray concrete, flowing after the gray concrete for a while before being blocked and hardened. The advance of the colouring along the pipe wall (showing boundary flow rate) was observed on the moulded concrete surface appearing after removing the pipe from the hardened concrete. The shapes of the interfaces between uncoloured and coloured concrete (showing variation of flow rate over the pipe cross section) were observed on sawn surfaces of concrete half cylinders cut along the length axes of the concrete-filled pipe. Flow profiles over the pipe cross section were clearly seen with maximum flow rates near the centre of the pipe and low flow rate at the pipe wall (typically rubber pipe with reference concrete without silica fume and/or stabilizers). More plug-shaped profiles, with long slip layers and less variation of flow rate over the cross section, were also seen (typically in smooth acrylic pipes). Flow rate, amount of concrete sticking to the wall after flow and SEM-images of pipe surface roughness were observed, illustrating the problem of testing full scale pumping.

Jacobsen, Stefan, E-mail: stefan.jacobsen@ntnu.n [Norwegian University of Science and Technology, Dept of Structural Engineering, Trondheim (Norway); Haugan, Lars; Hammer, Tor Arne [SINTEF Byggforsk AS Building and Infrastructure, Trondheim (Norway); Kalogiannidis, Evangelos [Norwegian University of Science and Technology, Dept of Structural Engineering, Trondheim (Norway)

2009-11-15

131

Computation of flow-induced vibrations in piping systems  

Microsoft Academic Search

Local pressure fluctuations and associated acoustic sources in piping systems are experimentally characterized for several current singularities. Attention is then given to the response problem of piping system to such sources: a theoretical formulation for the modal characteristics and transfer function computation of piping systems conveying fluid is presented. The results of an experimental test are compared with the TEDEL

R. J. Gibert

1980-01-01

132

NAS Grid Benchmarks. 1.0  

NASA Technical Reports Server (NTRS)

We provide a paper-and-pencil specification of a benchmark suite for computational grids. It is based on the NAS (NASA Advanced Supercomputing) Parallel Benchmarks (NPB) and is called the NAS Grid Benchmarks (NGB). NGB problems are presented as data flow graphs encapsulating an instance of a slightly modified NPB task in each graph node, which communicates with other nodes by sending/receiving initialization data. Like NPB, NGB specifies several different classes (problem sizes). In this report we describe classes S, W, and A, and provide verification values for each. The implementor has the freedom to choose any language, grid environment, security model, fault tolerance/error correction mechanism, etc., as long as the resulting implementation passes the verification test and reports the turnaround time of the benchmark.

VanderWijngaart, Rob; Frumkin, Michael; Biegel, Bryan A. (Technical Monitor)

2002-01-01

133

Corrosion problem solutions for pipe and equipment during manufacture, fabrication, and storage using vapor corrosion inhibitors (VCI`s) and dry air  

SciTech Connect

This paper presents current technology and use of environmentally friendly, cost effective materials and techniques for pipe and equipment preservation. This includes the use of Temporary Inhibitor Coatings (TIC), Vapor Corrosion Inhibitors (VCI), and dehumidified air (DH). Materials are described in detail, and applications of each are discussed.

Gelner, L. [Protec, Inc., North Hampton, NH (United States)

1998-12-31

134

Magnetohydrodynamic pipe flow. Part 1  

Microsoft Academic Search

The solution is obtained to the problem of the steady onedimensional ; flow of an incompressible, viscous, electrically fluid through a circular pipe in ; the presence of an applied (transverse) uniform magnetic field. A no-slip ; condition on the velocity is assumed at the nonconducting wall. The solution is ; exact and thus valid for all values of the

Richard R. Gold

1962-01-01

135

Organ pipe resonance induced vibration in piping system  

SciTech Connect

Acoustic-induced vibration is a fluid-structure interaction phenomenon. The feedback mechanism between the acoustic pressure pulsation and the structure movements determines the excited acoustic modes which, in turn, amplify the structure response when confidence frequency and mode shape matching occurs. The acoustic modes are not determined from the acoustic boundary conditions alone, structure feedback is as responsible for determining the acoustic modes and shaping the resulting forcing functions. Acoustic-induced piping vibration, when excited, does not attenuate much with distance. Pressure pulsation can be transmitted throughout the piping system and its branch connections. It is this property that makes vibration monitoring difficult, because vibration can surface at locations far away from the acoustic source when resonance occurs. For a large piping system with interconnected branches, the monitoring task can be formidable, particularly when there is no indication what the real source is. In organ pipe resonance induced vibration, the initiating acoustic source may be inconspicuous or unavoidable during operation. In these situations, the forcing function approach can offer an optimal tool for vibration assessment. The forcing function approach was used in the evaluation of a standby steam piping vibration problem. Monitoring locations and instrument specifications were determined from the acoustic eigenfunction profiles. Measured data confirmed the presence of coherent vibrations in the large bore piping. The developed forcing function permits design evaluation of the piping system, which leads to remedial actions and enables fatigue life determination, thus providing confidence to system operation. The forcing function approach is shown to be useful in finding potential vibration area and verifying the integrity of weak structure links. Application is to steam lines at BWR plants.

Wang, T.

1996-12-01

136

The 007 Benchmark  

Microsoft Academic Search

The OO7 Benchmark represents a comprehensive test of OODBMS performance. In this paper we describe the benchmark and present performance results from its implementation in three OODBMS systems. It is our hope that the OO7 Benchmark will provide useful insight for end-users evaluating the performance of OODBMS systems; we also hope that the research community will find that OO7 provides

Michael J. Carey; David J. DeWitt; Jeffrey F. Naughton

1993-01-01

137

The oo7 Benchmark  

Microsoft Academic Search

The OO7 Benchmark represents a comprehensive test of OODBMS performance. In thisreport we describe the benchmark and present performance results from its implementationin four OODB systems. It is our hope that the OO7 Benchmark will provide useful insightfor end-users evaluating the performance of OODB systems# we also hope that the researchcommunity will find that OO7 provides a database schema, instance,

Michael J. Carey; David J. Dewitt; Jeffrey F. Naughton

1993-01-01

138

Genetic Operators and Constraint Handling for Pipe Network Optimization  

Microsoft Academic Search

Evolution Programs (EPs), including Genetic Algorithms and Evolution Strategies, are well-suited for pipe network optimization problems due to the large number of candidate solutions to be examined, non-linearity of the problem and discrete decision space. However, pipe network problems are highly constrained and random initialization and standard genetic operators often cause infeasibility of generated solutions. The paper describes coding and

Dragan A. Savic; Godfrey A. Walters

1995-01-01

139

Local Search with Memory: Benchmarking RTS  

Microsoft Academic Search

Summary The purpose of this work is that of presenting a version of the Reactive Tabu Search method (RTS) that is suitable for constrained problems, and that of testing RTS on a series of constrained and unconstrained Combinatorial Optimization tasks. The benchmark suite consists of many instances of the N-K model and of the Knapsack problem with various sizes and

Roberto Battiti; Giampietro Tecchiolli

1994-01-01

140

Thermal Performance Benchmarking (Presentation)  

SciTech Connect

This project will benchmark the thermal characteristics of automotive power electronics and electric motor thermal management systems. Recent vehicle systems will be benchmarked to establish baseline metrics, evaluate advantages and disadvantages of different thermal management systems, and identify areas of improvement to advance the state-of-the-art.

Moreno, G.

2014-11-01

141

A Synthetic Benchmark  

Microsoft Academic Search

A simple method of measuring performance is by means of a benchmark pro- gram. Unless such a program is carefully constructed it is unlikely to be typical of the many thousands of programs run at an installation. An example benchmark for measuring the processor power of scientific computers is presented: this is compared with other methods of assessing computer power.

H. J. Curnow; Brian A. Wichmann

1976-01-01

142

USGS Yosemite Benchmark Streamgage  

USGS Multimedia Gallery

In this image, the USGS Hydrologic Benchmark Streamgage on the Merced River in Yosemite Valley can be seen. Hydrologic Benchmark streamgages are those at which no human development exists upstream of the streamgage. This streamgage is a cooperation between the National Park Service, National Oceanic...

143

IU parallel processing benchmark  

Microsoft Academic Search

A benchmark is presented that was designed to evaluate the merits of various parallel architectures as applied to image understanding (IU). This benchmark exercise addresses the issue of system performance on an integrated set of tasks, where the task interactions that are typical of complex vision application are present. The goal of this exercise is to gain a better understanding

Charles Weems; Edward Riseman; Allen Hanson; Azriel Rosenfeld

1988-01-01

144

BENCHMARK DOSE SOFTWARE (BMDS)  

EPA Science Inventory

EPA has announced the latest update to the Benchmark Dose Software (BMDS) tool which is used to facilitate the application of benchmark dose (BMD) methods to EPA hazardous pollutant risk assessments. This latest version (1.4.1b) contains seventeen (17) different models that ar...

145

WIPP Benchmark calculations with the large strain SPECTROM codes  

SciTech Connect

This report provides calculational results from the updated Lagrangian structural finite-element programs SPECTROM-32 and SPECTROM-333 for the purpose of qualifying these codes to perform analyses of structural situations in the Waste Isolation Pilot Plant (WIPP). Results are presented for the Second WIPP Benchmark (Benchmark II) Problems and for a simplified heated room problem used in a parallel design calculation study. The Benchmark II problems consist of an isothermal room problem and a heated room problem. The stratigraphy involves 27 distinct geologic layers including ten clay seams of which four are modeled as frictionless sliding interfaces. The analyses of the Benchmark II problems consider a 10-year simulation period. The evaluation of nine structural codes used in the Benchmark II problems shows that inclusion of finite-strain effects is not as significant as observed for the simplified heated room problem, and a variety of finite-strain and small-strain formulations produced similar results. The simplified heated room problem provides stratigraphic complexity equivalent to the Benchmark II problems but neglects sliding along the clay seams. The simplified heated problem does, however, provide a calculational check case where the small strain-formulation produced room closures about 20 percent greater than those obtained using finite-strain formulations. A discussion is given of each of the solved problems, and the computational results are compared with available published results. In general, the results of the two SPECTROM large strain codes compare favorably with results from other codes used to solve the problems.

Callahan, G.D.; DeVries, K.L. [RE/SPEC, Inc., Rapid City, SD (United States)

1995-08-01

146

NAS Parallel Benchmark (Version 1.0) Results 11-96  

Microsoft Academic Search

The NAS Parallel Benchmarks have been developed at NASA Ames Research Center to study the performance of parallel supercomputers. The eight benchmark problems are specified in a ''pencil and paper'' fashion. In other words, the complete details of the problem to be solved are given in a technical document, and except for a few restrictions, benchmarkers are free to select

Subhash Saini; David H. Bailey

147

Verification and validation benchmarks.  

SciTech Connect

Verification and validation (V&V) are the primary means to assess the accuracy and reliability of computational simulations. V&V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V&V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the level of achievement in V&V activities, how closely related the V&V benchmarks are to the actual application of interest, and the quantification of uncertainties related to the application of interest.

Oberkampf, William Louis; Trucano, Timothy Guy

2007-02-01

148

NAS Parallel Benchmarks I\\/O Version 2.4  

Microsoft Academic Search

We describe a benchmark problem, based on the Block-Tridiagonal (BT) prob- lem of the NAS Parallel Benchmarks (NPB), which is used to test the output capa- bilities of high-performance computing systems, especially parallel systems. We also present a source code implementation of the benchmark, called NPBIO2.4- MPI, based on the MPI implementation of NPB, using a variety of ways to

Parkson Wong; Rob F. Van der Wijngaart

2003-01-01

149

Heat pipe system  

Microsoft Academic Search

A heat pipe diode device for transferring heat from a heat source component to a heat sink wall is described. It contains a heat pipe body member attached to the best source; the heat source having a wall forming at least a portion of the normal evaporator section of the heat pipe diode; a working fluid within the body member;

H. L. Kroebig; F. J. Riha

1974-01-01

150

Heat pipes. [technology utilization  

NASA Technical Reports Server (NTRS)

The development and use of heat pipes are described, including space requirements and contributions. Controllable heat pipes, and designs for automatically maintaining a selected constant temperature, are discussed which would add to the versatility and usefulness of heat pipes in industrial processing, manufacture of integrated circuits, and in temperature stabilization of electronics.

1975-01-01

151

Singing Corrugated Pipes  

ERIC Educational Resources Information Center

Presents theoretical and experimental observations made with a musical toy called Hummer consisting of a corrugated flexible plastic tube about three-feet long and one-inch diam open at both ends. Included are descriptions of three new instruments: the Water Pipe, the Gas-Pipe Corrugahorn Bugle, and the Gas-Pipe Blues Corrugahorn. (CC)

Crawford, Frank S.

1974-01-01

152

Benchmarking expert system tools  

NASA Technical Reports Server (NTRS)

As part of its evaluation of new technologies, the Artificial Intelligence Section of the Mission Planning and Analysis Div. at NASA-Johnson has made timing tests of several expert system building tools. Among the production systems tested were Automated Reasoning Tool, several versions of OPS5, and CLIPS (C Language Integrated Production System), an expert system builder developed by the AI section. Also included in the test were a Zetalisp version of the benchmark along with four versions of the benchmark written in Knowledge Engineering Environment, an object oriented, frame based expert system tool. The benchmarks used for testing are studied.

Riley, Gary

1988-01-01

153

Benchmark Solutions for Computational Aeroacoustics (CAA) Code Validation  

NASA Technical Reports Server (NTRS)

NASA has conducted a series of Computational Aeroacoustics (CAA) Workshops on Benchmark Problems to develop a set of realistic CAA problems that can be used for code validation. In the Third (1999) and Fourth (2003) Workshops, the single airfoil gust response problem, with real geometry effects, was included as one of the benchmark problems. Respondents were asked to calculate the airfoil RMS pressure and far-field acoustic intensity for different airfoil geometries and a wide range of gust frequencies. This paper presents the validated that have been obtained to the benchmark problem, and in addition, compares them with classical flat plate results. It is seen that airfoil geometry has a strong effect on the airfoil unsteady pressure, and a significant effect on the far-field acoustic intensity. Those parts of the benchmark problem that have not yet been adequately solved are identified and presented as a challenge to the CAA research community.

Scott, James R.

2004-01-01

154

Diagnostic Algorithm Benchmarking  

NASA Technical Reports Server (NTRS)

A poster for the NASA Aviation Safety Program Annual Technical Meeting. It describes empirical benchmarking on diagnostic algorithms using data from the ADAPT Electrical Power System testbed and a diagnostic software framework.

Poll, Scott

2011-01-01

155

Toxicological Benchmarks for Wildlife  

Microsoft Academic Search

Ecological risks of environmental contaminants are evaluated by using a two-tiered process. In the first tier, a screening assessment is performed where concentrations of contaminants in the environment are compared to no observed adverse effects level (NOAEL)-based toxicological benchmarks. These benchmarks represent concentrations of chemicals (i.e., concentrations presumed to be nonhazardous to the biota) in environmental media (water, sediment, soil,

B. E. Opresko; D. M. Suter

1993-01-01

156

Object operations benchmark  

Microsoft Academic Search

Performance is a major issue in the acceptance of object-oriented and relational database systems aimed at engineering applications such as computer-aided software engineering (CASE) and computer-aided design (CAD). Because traditional database systems benchmarks are inapproriate to measure performance for operations on engineering objects, we designed a new benchmark Object Operations version 1 (OO1) to focus on important characteristics of these

R. G. G. Cattell; J. Skeen

1992-01-01

157

Benchmarking a network storage service  

Microsoft Academic Search

Benchmarking a network file server introduces some unique considerations over traditional benchmarking scenarios. Since the user is executing on a client system interconnected to the file server, the client and network must be provided for during benchmarking. During a recent procurement action, Sandia National Laboratories (SNL) was challenged to develop a benchmark suite that would accurately test the network requirements.

Suzanne M. Kelly; Rena A. Haynes; M. J. Ernest

1991-01-01

158

Full sphere hydrodynamic and dynamo benchmarks  

NASA Astrophysics Data System (ADS)

Convection in planetary cores can generate fluid flow and magnetic fields, and a number of sophisticated codes exist to simulate the dynamic behaviour of such systems. We report on the first community activity to compare numerical results of computer codes designed to calculate fluid flow within a whole sphere. The flows are incompressible and rapidly rotating and the forcing of the flow is either due to thermal convection or due to moving boundaries. All problems defined have solutions that allow easy comparison, since they are either steady, slowly drifting or perfectly periodic. The first two benchmarks are defined based on uniform internal heating within the sphere under the Boussinesq approximation with boundary conditions that are uniform in temperature and stress-free for the flow. Benchmark 1 is purely hydrodynamic, and has a drifting solution. Benchmark 2 is a magnetohydrodynamic benchmark that can generate oscillatory, purely periodic, flows and magnetic fields. In contrast, Benchmark 3 is a hydrodynamic rotating bubble benchmark using no slip boundary conditions that has a stationary solution. Results from a variety of types of code are reported, including codes that are fully spectral (based on spherical harmonic expansions in angular coordinates and polynomial expansions in radius), mixed spectral and finite difference, finite volume, finite element and also a mixed Fourier-finite element code. There is good agreement between codes. It is found that in Benchmarks 1 and 2, the approximation of a whole sphere problem by a domain that is a spherical shell (a sphere possessing an inner core) does not represent an adequate approximation to the system, since the results differ from whole sphere results.

Marti, P.; Schaeffer, N.; Hollerbach, R.; Cébron, D.; Nore, C.; Luddens, F.; Guermond, J.-L.; Aubert, J.; Takehiro, S.; Sasaki, Y.; Hayashi, Y.-Y.; Simitev, R.; Busse, F.; Vantieghem, S.; Jackson, A.

2014-04-01

159

Remotely operated pipe connector  

SciTech Connect

An apparatus for remotely assembling and disassembling a connector between a pipe and a closure for the pipe is described, wherein the connector includes an angled flange defining an annular camming surface on the end of the pipe, an angled flange defining an annular camming surface on the closure, two semicircular collars which surround the flanges on the pipe and the closure, each of the collars having annular camming surfaces thereon adapted to contact the annular camming surfaces on the pipe and closure, a nut and bolt means extending through the two collars at each side for drawing the collars together, and an annular sealing ring located between the pipe and closure. The sealing ring is compressed between the pipe and the closure as the camming action of the camming surfaces on the collars against the camming surfaces on the pipe and closure draws the pipe and closure toward one another. The apparatus comprises: a base, a receptacle on the base, the closure being positioned on the receptacle with the flange of the closure upwardmost and horizontally disposed, and the sealing ring resting on the flange; a positioning means for moving the pipe into position vertically above the closure with the flange on the end of the pipe immediately adjacent to and the sealing ring resting on the flange of the closure; a moving means for each collar for reciprocally moving each collar horizontally from a position free of the closure to a position such that the annular camming surfaces on each collar are in contact with the annular camming surfaces on the pipe and closure; and a tensioning means for automatically tightening the nut and bolt means in each side of the collars to draw the collars together and thereby draw the pipe and closure toward one another to cause the seal ring to be compressed between the pipe and closure.

Josefiak, L.J.; Cramer, C.E.

1988-02-16

160

Performance Results for Two of the NAS Parallel Benchmarks David H. Bailey Paul O. Frederickson  

E-print Network

Performance Results for Two of the NAS Parallel Benchmarks David H. Bailey Paul O. Frederickson NAS Moffett Field, CA 94035 Abstract Two problems from the recently published "NAS Parallel Benchmarks" have been implemented on three advanced parallel computer systems. These two benchmarks are the following

Bailey, David H.

161

The LINPACK Benchmark: Past, Present, and Future Jack J. Dongarra, Piotr Luszczek, and Antoine Petitet  

E-print Network

program), and a scalable parallel problem. The names and rules for running the LINPACK suite of benchmarks: (+865) 974-8295, Fax: (+865) 974- #12;Benchmark Matrix Optimizations Parallel name dimension allowedThe LINPACK Benchmark: Past, Present, and Future Jack J. Dongarra, Piotr Luszczek, and Antoine

Luszczek, Piotr

162

Abrasion resistant heat pipe  

DOEpatents

A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

Ernst, D.M.

1984-10-23

163

The FTIO Benchmark  

NASA Technical Reports Server (NTRS)

We introduce a new benchmark for measuring the performance of parallel input/ouput. This benchmark has flexible initialization. size. and scaling properties that allows it to satisfy seven criteria for practical parallel I/O benchmarks. We obtained performance results while running on the a SGI Origin2OOO computer with various numbers of processors: with 4 processors. the performance was 68.9 Mflop/s with 0.52 of the time spent on I/O, with 8 processors the performance was 139.3 Mflop/s with 0.50 of the time spent on I/O, with 16 processors the performance was 173.6 Mflop/s with 0.43 of the time spent on I/O. and with 32 processors the performance was 259.1 Mflop/s with 0.47 of the time spent on I/O.

Fagerstrom, Frederick C.; Kuszmaul, Christopher L.; Woo, Alex C. (Technical Monitor)

1999-01-01

164

Accelerated randomized benchmarking  

NASA Astrophysics Data System (ADS)

Quantum information processing offers promising advances for a wide range of fields and applications, provided that we can efficiently assess the performance of the control applied in candidate systems. That is, we must be able to determine whether we have implemented a desired gate, and refine accordingly. Randomized benchmarking reduces the difficulty of this task by exploiting symmetries in quantum operations. Here, we bound the resources required for benchmarking and show that, with prior information, we can achieve several orders of magnitude better accuracy than in traditional approaches to benchmarking. Moreover, by building on state-of-the-art classical algorithms, we reach these accuracies with near-optimal resources. Our approach requires an order of magnitude less data to achieve the same accuracies and to provide online estimates of the errors in the reported fidelities. We also show that our approach is useful for physical devices by comparing to simulations.

Granade, Christopher; Ferrie, Christopher; Cory, D. G.

2015-01-01

165

Heat Pipe Materials Compatibility  

NASA Technical Reports Server (NTRS)

An experimental program to evaluate noncondensable gas generation in ammonia heat pipes was completed. A total of 37 heat pipes made of aluminum, stainless steel and combinations of these materials were processed by various techniques, operated at different temperatures and tested at low temperature to quantitatively determine gas generation rates. In order of increasing stability are aluminum/stainless combination, all aluminum and all stainless heat pipes. One interesting result is the identification of intentionally introduced water in the ammonia during a reflux step as a means of surface passivation to reduce gas generation in stainless-steel/aluminum heat pipes.

Eninger, J. E.; Fleischman, G. L.; Luedke, E. E.

1976-01-01

166

External artery heat pipe  

NASA Technical Reports Server (NTRS)

An improved heat pipe with an external artery. The longitudinal slot in the heat pipe wall which interconnects the heat pipe vapor space with the external artery is completely filled with sintered wick material and the wall of the external artery is also covered with sintered wick material. This added wick structure assures that the external artery will continue to feed liquid to the heat pipe evaporator even if a vapor bubble forms within and would otherwise block the liquid transport function of the external artery.

Gernert, Nelson J. (Inventor); Ernst, Donald M. (Inventor); Shaubach, Robert M. (Inventor)

1989-01-01

167

Internal pipe attachment mechanism  

DOEpatents

An attachment mechanism is described for repairing or extending fluid carrying pipes, casings, conduits, etc. utilizing one-way motion of spring tempered fingers to provide a mechanical connection between the attachment mechanism and the pipe. The spring tempered fingers flex to permit insertion into a pipe to a desired insertion depth. The mechanical connection is accomplished by reversing the insertion motion and the mechanical leverage in the fingers forces them outwardly against the inner wall of the pipe. A seal is generated by crushing a sealing assembly by the action of setting the mechanical connection. 6 figures.

Bast, R.M.; Chesnut, D.A.; Henning, C.D.; Lennon, J.P.; Pastrnak, J.W.; Smith, J.A.

1994-12-13

168

The NAS Parallel Benchmarks in Titanium  

E-print Network

Titanium is an explicitly parallel dialect of Java TM designed for high-performance scientific programming. It offers object-orientation, strong typing, and safe memory management in the context of a language that supports high performance and scalable parallelism. We present an overview of the language features and demonstrate their use in the context of the NAS Parallel Benchmarks, a benchmark suite of common scientific kernels. We argue that parallel languages like Titanium provide greater expressive power than conventional approaches, thereby enabling more concise and expressive code and minimizing time to solution. Moreover, the Titanium implementations of three of the NAS Parallel Benchmarks can match or even exceed the performance of the standard Fortran/MPI implementations at realistic problem sizes and processor scales, while still using far cleaner, shorter and more maintainable code.

Kaushik Datta; Kaushik Datta

169

Benchmarking the Urology Practice  

PubMed Central

The medical practice today is relentlessly challenged by medical progress, by rising costs, and by the mounting pressures of the managed care environment. It should be the approach of every medical practice manager and practitioner to seek out and measure up to the best standards so as to optimize patient care and business outcomes. This requires the resolute pursuit of good models, brought about by the fostering of key collaborative relationships that are both practical and strategic. Integral to this process is benchmarking: the way by which information is obtained from both internal and external sources to determine and set the standards for performance. Benchmarking is an invaluable strategic tool. PMID:19107215

Brower, Paul A.

2008-01-01

170

An overview of American Nuclear Society Mathematics and Computation Division benchmark activities  

SciTech Connect

A review of the objectives and accomplishments of the Computational Benchmark Problem Committee (CBPC) of the American Nuclear Society Mathematics and Computation Division is presented. A list of the benchmark problems compiled by the CBPC and published by the Argonne Code Center is included, along with a list of the problems currently under review. A brief discussion of the challenge of benchmarking in the current environment of rapidly evolving computing technology is given. 20 refs., 3 tabs.

Badruzzaman, A.

1991-01-01

171

Benchmarks: WICHE Region 2012  

ERIC Educational Resources Information Center

Benchmarks: WICHE Region 2012 presents information on the West's progress in improving access to, success in, and financing of higher education. The information is updated annually to monitor change over time and encourage its use as a tool for informed discussion in policy and education communities. To establish a general context for the…

Western Interstate Commission for Higher Education, 2013

2013-01-01

172

Benchmark Comparisons August 2006  

E-print Network

administered oversamples are not included. Mean The mean is the weighted arithmetic average of student level Comparisons Report Class Mean a Sig b Effect Size c Mean a Sig b Effect Size c Mean a Sig b Effect Size c Benchmark Mean Comparisons NSSE 2006 51.9 NSSEville State compared with: 54.3 Mean a NSSEville State Level

Rainforth, Emma C.

173

Bryce Canyon Benchmark  

USGS Multimedia Gallery

A USGS elevation benchmark in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that ...

174

Cast Bronze Benchmark  

USGS Multimedia Gallery

Benchmarks can be divided into two general groups: the "vertical control points" are points that mark a very precise elevation above the standard datum plane (usually referred to as elevation above sea level) and the "horizontal control points" are points with precisely established latitude and long...

2009-07-22

175

Surveys and Benchmarks  

ERIC Educational Resources Information Center

Surveys and benchmarks continue to grow in importance for community colleges in response to several factors. One is the press for accountability, that is, for colleges to report the outcomes of their programs and services to demonstrate their quality and prudent use of resources, primarily to external constituents and governing boards at the state…

Bers, Trudy

2012-01-01

176

Benchmarks Momentum on Increase  

ERIC Educational Resources Information Center

No longer content with the patchwork quilt of assessments used to measure states' K-12 performance, top policy groups are pushing states toward international benchmarking as a way to better prepare students for a competitive global economy. The National Governors Association, the Council of Chief State School Officers, and the standards-advocacy…

McNeil, Michele

2008-01-01

177

Resources for Educational Benchmarks  

NSDL National Science Digital Library

The Resources for Educational Benchmarks connects learning resources to the NSDL Science Literacy Maps. The Science Literacy Maps illustrate connections between science concepts and show how they build upon one another across grade levels. Science Literacy Maps are intended to serve as a browsing interface to NSDL resources, allowing teachers and students to find resources that relate to specific science and math concepts.

2008-04-18

178

Airport Capacity Benchmark Report 2001  

NSDL National Science Digital Library

Released in April 2001 by the FAA (Federal Aviation Administration), this report provides the first capacity benchmarks for 31 of the nation's busiest airports. Capacity benchmarks are defined as "the maximum number of flights an airport can routinely handle in an hour." The report finds, among other things, that at a number of airports so many flights are scheduled that it is simply not possible for all of them to take off and land on time. The worst offender in 2000 was New York LaGuardia, with 15.6 percent of takeoffs or landings delayed, more than twice as many as the second-ranked airport, Chicago O'Hare. Predictably, opinion is divided on the root of the problem, with the airlines blaming an antiquated air traffic control system and too few runways and critics blaming the airlines for over-scheduling at peak travel times. The full text of the 195-page report may be downloaded in .pdf or Word format at the FAA site.

2001-01-01

179

Verification and benchmarking of ABAQUS and PATRAN for heat transfer applications  

SciTech Connect

This report contains the verification and benchmarking performed at the Idaho National Engineering Laboratory (INEL) on ABAQUS and PATRAN for heat transfer calculations. ABAQUS and PATRAN were used to perform the thermal analysis of the Advanced Test Reactor (ATR) loop 2A piping components. These codes are commercially available and are used extensively within the industry to solve structural and heat transfer problems using finite element methods. They have been extensively verified and documented by the companies developing and providing them. This report documents work performed by EG G Idaho Inc. to further verify that ABAQUS and PATRAN properly solve a variety of heat transfer problems and that performance on the INEL computers was the same as on the developer's computers. Methods employed to verify ABAQUS and PATRAN are presented within this report. Heat transfer problems with known exact solutions are compared to ABAQUS results. Computer output from the ABAQUS introductory workbook was compared to calculations performed on INEL computers using the same input deck. The verification of ABAQUS and PATRAN at INEL has shown the codes applicable to solve heat transfer problems encountered at INEL. 7 refs., 2 figs., 2 tabs.

Hawkes, G.L.

1989-08-01

180

NAS Parallel Benchmarks Results 3-95  

NASA Technical Reports Server (NTRS)

The NAS Parallel Benchmarks (NPB) were developed in 1991 at NASA Ames Research Center to study the performance of parallel supercomputers. The eight benchmark problems are specified in a "pencil and paper" fashion, i.e., the complete details of the problem are given in a NAS technical document. Except for a few restrictions, benchmark implementors are free to select the language constructs and implementation techniques best suited for a particular system. In this paper, we present new NPB performance results for the following systems: (a) Parallel-Vector Processors: CRAY C90, CRAY T90 and Fujitsu VPP500; (b) Highly Parallel Processors: CRAY T3D, IBM SP2-WN (Wide Nodes), and IBM SP2-TN2 (Thin Nodes 2); and (c) Symmetric Multiprocessors: Convex Exemplar SPPIOOO, CRAY J90, DEC Alpha Server 8400 5/300, and SGI Power Challenge XL (75 MHz). We also present sustained performance per dollar for Class B LU, SP and BT benchmarks. We also mention future NAS plans for the NPB.

Saini, Subhash; Bailey, David H.; Walter, Howard (Technical Monitor)

1995-01-01

181

Avoid freeze-up of steam traps and their piping  

Microsoft Academic Search

This article addresses the problem of keeping steam traps free of ice in cold weather. The topics of the article include piping configurations and trap types that contribute to freezing, freeze damage, obstructions in piping, insulation of lines to retard freezing, common manifolds for heating of condensate, draining of low points, temperature-actuated devices, and water hammer damage.

OKeefe

1993-01-01

182

Avoid freeze-up of steam traps and their piping  

SciTech Connect

This article addresses the problem of keeping steam traps free of ice in cold weather. The topics of the article include piping configurations and trap types that contribute to freezing, freeze damage, obstructions in piping, insulation of lines to retard freezing, common manifolds for heating of condensate, draining of low points, temperature-actuated devices, and water hammer damage.

O'Keefe, W.

1993-12-01

183

Analysis of Rotary Bayonets and Piping  

SciTech Connect

This report quantifies certain characteristics of the rotary bayonets and associated platform piping on the DO detector. The Vacuum Jacketed 4-inch x 6-inch and 1.5-inch x 3-inch and the 4-inch and 6-inch vacuum pipe articulating jumpers are considered here. The values of greatest importance are the forces required at the bayonet moment arms given in Table II and the stresses summarized in Table III. The forces required should be noted and checked that they are acceptable to the problem. The maximum bending stresses of the vacuum pipes do not exceed 1000 psi and are essentially negligible. The 4-inch x 6-inch vacuum jacketed line experiences the maximum bending stress of 10,300 psi. According to code B31.1, the maximum allowable bending stress is 25,500 psi. The major sources of error in these calculations should be summarized. First, all weights used were approximations and all lengths used were scaled from drawings. Second, while the FRAME MAC{trademark} models resemble the vacuum pipe articulating jumpers, they are definitely simplified. For instance, they do not account for the different stiffnesses of the unions. Finally, the bayonets in the ANSYS models consist of an outer jacket and an inner pipe fixed together at the end of the male sleeve. The actual bayonets are more complex and are composed of various sizes of tubes and pipes which affect the stiffness of the section.

Chess, K.; Wendlandt, J.; /Fermilab

1988-08-19

184

Quantum benchmarks for pure single-mode Gaussian states.  

PubMed

Teleportation and storage of continuous variable states of light and atoms are essential building blocks for the realization of large-scale quantum networks. Rigorous validation of these implementations require identifying, and surpassing, benchmarks set by the most effective strategies attainable without the use of quantum resources. Such benchmarks have been established for special families of input states, like coherent states and particular subclasses of squeezed states. Here we solve the longstanding problem of defining quantum benchmarks for general pure Gaussian single-mode states with arbitrary phase, displacement, and squeezing, randomly sampled according to a realistic prior distribution. As a special case, we show that the fidelity benchmark for teleporting squeezed states with totally random phase and squeezing degree is 1/2, equal to the corresponding one for coherent states. We discuss the use of entangled resources to beat the benchmarks in experiments. PMID:24483875

Chiribella, Giulio; Adesso, Gerardo

2014-01-10

185

Quantum Benchmarks for Pure Single-Mode Gaussian States  

NASA Astrophysics Data System (ADS)

Teleportation and storage of continuous variable states of light and atoms are essential building blocks for the realization of large-scale quantum networks. Rigorous validation of these implementations require identifying, and surpassing, benchmarks set by the most effective strategies attainable without the use of quantum resources. Such benchmarks have been established for special families of input states, like coherent states and particular subclasses of squeezed states. Here we solve the longstanding problem of defining quantum benchmarks for general pure Gaussian single-mode states with arbitrary phase, displacement, and squeezing, randomly sampled according to a realistic prior distribution. As a special case, we show that the fidelity benchmark for teleporting squeezed states with totally random phase and squeezing degree is 1/2, equal to the corresponding one for coherent states. We discuss the use of entangled resources to beat the benchmarks in experiments.

Chiribella, Giulio; Adesso, Gerardo

2014-01-01

186

Verification and benchmarking of ABAQUS and PATRAN for heat transfer applications  

Microsoft Academic Search

This report contains the verification and benchmarking performed at the Idaho National Engineering Laboratory (INEL) on ABAQUS and PATRAN for heat transfer calculations. ABAQUS and PATRAN were used to perform the thermal analysis of the Advanced Test Reactor (ATR) loop 2A piping components. These codes are commercially available and are used extensively within the industry to solve structural and heat

Hawkes

1989-01-01

187

Common causes of material degradation in buried piping  

SciTech Connect

Buried pipe may fail for innumerable reasons. Causes can be mechanical damage/breakage, chemically initiated corrosion, or a combination. Failures may originate either internally or externally on the pipe. They may be related to flaws in the design, to excessive or unanticipated internal pressure or ground level loading, and/or to poor or uncertain installation practice. Or the pipe may simply ``wear out`` in service. Steel is strong and very forgiving in underground applications, especially with regard to backfill. However, soil support developed through densification or compaction is critical for brittle concrete and vitrified clay tile pipe, and is very important for cast iron and plastic pipe. Chemistry of the soil determines whether or not it will enhance corrosion or other types of degradation. Various causes and mechanisms for deterioration of buried pipe are indicated. Some peculiarities of the different materials of construction are characterized. Repair methods and means to circumvent special problems are described.

Jenkins, C.F.

1997-01-20

188

Benchmarking The Influence of Information-Processing Architectures on Intelligent  

E-print Network

on intelligent robots. We separate this problem into two sub-problems: benchmarking the architecture design-overlooked, element of the science of designing and building intelligent robots (and other systems). This paper to intelligent system design has a number of problems (some of which this work- shop is trying to address

Wyatt, Jeremy

189

Computational evaluation of two reactor benchmark problems  

E-print Network

U238 F238 F239 F240 F241 F242 A 41 OX16 HYDR B 10 B 11 VECTOR 4 8 23 BEGINC * 8. 7 8 Pu pin FUEL CELL (NEA WPPR Bnch Phase 2) CELL 6 SEQUENCE 2 NGROUP 23 3 3 NMESH 25 25 NREGION 4 0 4 NMATERIAL 4 1 PREOUT INITIATE ANNULUS 1 0. 4095 1... DRVR4 0. 81788 06 DRVR5 17. 17548 06 DRVR6 17. 17548 06 DRVR7 33. 53308 06 DRVRB 33. 53308 06 DRVR9 49. 89068 06 DRVR10 49. 89068 06 DRVR11 58. 06948 06 DRVR12 58. 06948 09 X 0. 81788 09 Y 2 0. 81788 14 FUEL A1AO 1. 0 14 REFL B4BO 1. 0 15...

Cowan, James Anthony

2012-06-07

190

Benchmarking for Steganography  

Microsoft Academic Search

With the increasing number of new steganographic algorithms as well as methods for detecting them, the issue of comparing\\u000a security of steganographic schemes in a fair manner is of the most importance. A fair benchmark for steganography should only\\u000a be dependent on the model chosen to represent cover and stego objects. In particular, it should be independent of any specific

Tomás Pevný; Jessica J. Fridrich

2008-01-01

191

Benchmark Comparisons August 2006  

E-print Network

administered oversamples are not included. Mean The mean is the weighted arithmetic average of student level Report Class Mean a Sig b Effect Size c Mean a Sig b Effect Size c Mean a Sig b Effect Size c First-Year 53.0 51.6 52.6 Seniors 57.5 56.0 56.5 Level of Academic Challenge (LAC) Selected Peers Benchmark Mean

Haykin, Simon

192

Estimating with Benchmark Fractions  

NSDL National Science Digital Library

Teachers can use this interactive tool to help students develop fraction sense. After a teacher places a fraction, decimal, or expression on the screen, students determine which given benchmark number it is closest to. An adjustable number line supports conceptual understanding. This page includes a video demonstration of the tool and sample lessons from the Conceptua curriculum. Free registration is required to use the tool. A paid subscription is necessary to access full curriculum and allow full student use.

2011-01-01

193

Benchmarking Corporate Energy Management  

E-print Network

management practices at the corporate to energy manager levels. THE ENERGY TO OUTPUT INDEX It would be nice ifthere were a simple quantitative measure to how well a company managed its energy One measure that is often used is energy use per unit...BENCHMARKING CORPORATE ENERGY MANAGEMENT Dr. Douglas L. Norland Director of Research and Industrial Programs Alliance to Save Energy Washington, DC ABSTRACT There is growing interest among energy managers in finding out how their company...

Norland, D. L.

194

Mercury Flow through a Long Curved Pipe Wenhai Li & Foluso Ladeinde  

E-print Network

Mercury Flow through a Long Curved Pipe Wenhai Li & Foluso Ladeinde Department of Mechanical Engineering Stony Brook University Summary The flow of mercury in a long, curved pipe is simulated Description The problem is that of mercury flow in a curved pipe, with specific interest on the velocity

McDonald, Kirk

195

Automated Ultrasonic Pipe Weld Inspection  

Microsoft Academic Search

Summary This article contains an overview on automated ultrasonic w eld inspection for various pipe types. Some inspection steps might by carried out with portable t est equipment (e.g. pipe end test), but the weld inspection in all internationally relevant specif ications must be automated. The pipe geometry, the production process, and the further pipe usage determine if ND T

Wolfram A. Karl; Peter SCHULTE; Michael JOSWIG; Rainer KATTWINKEL

196

Flexible ultrasonic pipe inspection apparatus  

DOEpatents

Pipe crawlers, pipe inspection {open_quotes}rabbits{close_quotes} and similar vehicles are widely used for inspecting the interior surfaces of piping systems, storage tanks and process vessels for damaged or flawed structural features. This paper describes the design of a flexible, modular ultrasonic pipe inspection apparatus.

Jenkins, C.F.; Howard, B.D.

1994-01-01

197

Improved Thin, Flexible Heat Pipes  

NASA Technical Reports Server (NTRS)

Flexible heat pipes of an improved type are fabricated as layers of different materials laminated together into vacuum- tight sheets or tapes. In comparison with prior flexible heat pipes, these flexible heat pipes are less susceptible to leakage. Other advantages of these flexible heat pipes, relative to prior flexible heat pipes, include high reliability and greater ease and lower cost of fabrication. Because these heat pipes are very thin, they are highly flexible. When coated on outside surfaces with adhesives, these flexible heat pipes can be applied, like common adhesive tapes, to the surfaces of heat sinks and objects to be cooled, even if those surfaces are curved.

Rosenfeld, John H.; Gernert, Nelson J.; Sarraf, David B.; Wollen, Peter J.; Surina, Frank C.; Fale, John E.

2004-01-01

198

NAS Parallel Benchmarks I/O Version 2.4. 2.4  

NASA Technical Reports Server (NTRS)

We describe a benchmark problem, based on the Block-Tridiagonal (BT) problem of the NAS Parallel Benchmarks (NPB), which is used to test the output capabilities of high-performance computing systems, especially parallel systems. We also present a source code implementation of the benchmark, called NPBIO2.4-MPI, based on the MPI implementation of NPB, using a variety of ways to write the computed solutions to file.

Wong, Parkson; VanderWijngaart, Rob F.; Biegel, Bryan A. (Technical Monitor)

2002-01-01

199

Heat pipe development  

NASA Technical Reports Server (NTRS)

The objective of this program was to investigate analytically and experimentally the performance of heat pipes with composite wicks--specifically, those having pedestal arteries and screwthread circumferential grooves. An analytical model was developed to describe the effects of screwthreads and screen secondary wicks on the transport capability of the artery. The model describes the hydrodynamics of the circumferential flow in triangular grooves with azimuthally varying capillary menisci and liquid cross-sections. Normalized results were obtained which give the influence of evaporator heat flux on the axial heat transport capability of the arterial wick. In order to evaluate the priming behavior of composite wicks under actual load conditions, an 'inverted' glass heat pipe was designed and constructed. The results obtained from the analysis and from the tests with the glass heat pipe were applied to the OAO-C Level 5 heat pipe, and an improved correlation between predicted and measured evaporator and transport performance were obtained.

Bienart, W. B.

1973-01-01

200

Heat Pipe Systems  

NASA Technical Reports Server (NTRS)

The heat pipe was developed to alternately cool and heat without using energy or any moving parts. It enables non-rotating spacecraft to maintain a constant temperature when the surface exposed to the Sun is excessively hot and the non Sun-facing side is very cold. Several organizations, such as Tropic-Kool Engineering Corporation, joined NASA in a subsequent program to refine and commercialize the technology. Heat pipes have been installed in fast food restaurants in areas where humid conditions cause materials to deteriorate quickly. Moisture removal was increased by 30 percent in a Clearwater, FL Burger King after heat pipes were installed. Relative humidity and power consumption were also reduced significantly. Similar results were recorded by Taco Bell, which now specifies heat pipe systems in new restaurants in the Southeast.

1993-01-01

201

Heat pipe manufacturing study  

NASA Technical Reports Server (NTRS)

Heat pipe manufacturing methods are examined with the goal of establishing cost effective procedures that will ultimately result in cheaper more reliable heat pipes. Those methods which are commonly used by all heat pipe manufacturers have been considered, including: (1) envelope and wick cleaning, (2) end closure and welding, (3) mechanical verification, (4) evacuation and charging, (5) working fluid purity, and (6) charge tube pinch off. The study is limited to moderate temperature aluminum and stainless steel heat pipes with ammonia, Freon-21 and methanol working fluids. Review and evaluation of available manufacturers techniques and procedures together with the results of specific manufacturing oriented tests have yielded a set of recommended cost-effective specifications which can be used by all manufacturers.

Edelstein, F.

1974-01-01

202

Deterministic solutions for 3D Kobayashi benchmarks  

Microsoft Academic Search

We present results for the set of three-dimensional radiation transport benchmark problems with void region proposed by Kobayashi. Reference solutions for the pure absorber cases were obtained by direct quadrature. All cases were calculated by the three-dimensional discrete ordinates nodal and characteristics code IDT. The discrete ordinates results for the pure-absorber case suffer strongly from ray effects which remain present

Igor Zmijarevic; Richard Sanchez

2001-01-01

203

VVER-1000 weapons-grade MOX computational benchmark analysis  

SciTech Connect

Calculations of computational benchmark problems for the disposition of weapons-grade plutonium fuel in VVER-1000 reactors have been performed under the Joint US/Russian Fissile Material Disposition Program. The benchmarks cover pin cell, single fuel assembly, and multi-assembly structures with several different fuel types, moderator densities, and boron content for operational and off-normal conditions. Fuel depletion is performed to a burnup of 60 MWd/kgHM. The results of the analysis of the benchmarks with US and Russian code systems have been compared and indicated good agreement among the different methods and data.

Kalugin, M.A.; Lazarenko, A.P.; Kalahnikov, A.G.; Gehin, J.C.

2000-05-07

204

Transient analysis of the startup of a sodium heat pipe from a frozen state  

NASA Astrophysics Data System (ADS)

The capabilities of HPTAM, a two-dimensional Heat Pipe Transient Analysis Model, are extended to include modeling of free-molecular and transition vapor flow regimes during the startup from either a frozen state or fully-thawed condition of high-temperature heat pipes. The one-dimensional transient vapor flow model developed herein is based on the Dusty Gas Model. Results presented for the startup from a frozen state are successfully benchmarked using available experimental data for a radiatively-cooled sodium heat pipe.

Tournier, Jean-Michel; El-Genk, Mohamed S.

1996-03-01

205

A benchmark for galactic cosmic ray transport codes  

NASA Technical Reports Server (NTRS)

A nontrivial analytic benchmark solution for galactic cosmic ray transport is presented for use in transport code validation. Computational accuracy for a previously-developed cosmic ray transport code is established to within one percent by comparison with this exact benchmark. Hence, solution accuracy for the transport problem is mainly limited by inaccuracies in the input spectra, input interaction databases, and the use of a straight ahead/velocity-conserving approximation.

Wilson, John W.; Townsend, Lawrence W.

1987-01-01

206

Benchmark for galactic cosmic-ray transport codes  

SciTech Connect

A nontrivial analytic benchmark solution for galactic cosmic ray transport is presented for use in transport code validation. Computational accuracy for a previously-developed cosmic ray transport code is established to within one percent by comparison with this exact benchmark. Hence, solution accuracy for the transport problem is mainly limited by inaccuracies in the input spectra, input interaction databases, and the use of a straight ahead/velocity-conserving approximation. 9 references.

Wilson, J.W.; Townsend, L.W.

1988-01-01

207

Calculator programs for pipe stress engineering  

SciTech Connect

This book contains a collection of programs for solving a wide variety of stress problems using both the TI-59 and HP-41CV calculators. Each program is prefaced with a description of the problem to be solved, nomenclature, code restrictions and program limitations. Solutions are explained analytically and then followed by the complete program listing, documentation and checklists. Topics include calculations for pipewall thickness, pressure vessel analysis, reinforcement pads, allowable span, vibration, stress, and two-anchor piping systems.

Morgan, K.S.

1985-01-01

208

PIPES: A Portable Integrated Piping Engineering Interface System  

SciTech Connect

This paper describes software developed by the authors to integrate and automate several piping engineering applications for high-volume production use in the power and petrochemical industries. The system utilizes piping component geometry from a CAD model together with associated engineering and material data. It produces input for an industry-standard piping isometric drawing program, Electronic Data Interchange information for pipe spool fabrication, and input for several,common pipe stress analysis codes. The piping isometric drawings feature stress analysis data points and material tabulations. The software is based on an open architecture and incorporates rule-driven Expert System technology to provide flexibility and ease of customization.

Lee, N.L.; Kanga, D. [Bechtel Corp., Gaithersburg, MD (United States)

1995-12-01

209

Benchmarking, BOMA BESt and BBEER  

E-print Network

?or?worse?than?????? Energy?Use?Intensity?(EUI)?=?? total?energy?consumed?in?one?year?(ekWh)?/?total?floor?space?of? the?building?(ft2) Benchmarking and BBEER 2013 ? reliable?information on?energy?use?and?benefits?of?improvements; ? prioritize poorly...?energy?efficiency?among?building?occupants. BENCHMARKING ? Benefits Source:?NRCan Benchmarking and BBEER 2013 ABOUT BOMA BESt ? Program Description Building?Environmental?Standards?(BESt) ? Environmental?performance?and?management? practices?of?existing?buildings ? Five...

Smiciklas, J.

2013-01-01

210

Fast System Level Benchmarks for Multicore Architectures  

E-print Network

% similarity to the real benchmarks. Index Terms--Synthetic benchmarks, SystemC, Parallel pat- ternsFast System Level Benchmarks for Multicore Architectures Alper Sen, Gokcehan Kara Etem Deniz, Smail level synthetic benchmarks from traditional bench- marks. Synthetic benchmarks have similar performance

Sen, Alper

211

NAS Parallel Benchmarks. 2.4  

NASA Technical Reports Server (NTRS)

We describe a new problem size, called Class D, for the NAS Parallel Benchmarks (NPB), whose MPI source code implementation is being released as NPB 2.4. A brief rationale is given for how the new class is derived. We also describe the modifications made to the MPI (Message Passing Interface) implementation to allow the new class to be run on systems with 32-bit integers, and with moderate amounts of memory. Finally, we give the verification values for the new problem size.

VanderWijngaart, Rob; Biegel, Bryan A. (Technical Monitor)

2002-01-01

212

Perspective: Selected benchmarks from commercial CFD codes  

SciTech Connect

This paper summarizes the results of a series of five benchmark simulations which were completed using commercial Computational Fluid Dynamics (CFD) codes. These simulations were performed by the vendors themselves, and then reported by them in ASME`s CFD Triathlon Forum and CFD Biathlon Forum. The first group of benchmarks consisted of three laminar flow problems. These were the steady, two-dimensional flow over a backward-facing step, the low Reynolds number flow around a circular cylinder, and the unsteady three-dimensional flow in a shear-driven cubical cavity. The second group of benchmarks consisted of two turbulent flow problems. These were the two-dimensional flow around a square cylinder with periodic separated flow phenomena, and the stead, three-dimensional flow in a 180-degree square bend. All simulation results were evaluated against existing experimental data nd thereby satisfied item 10 of the Journal`s policy statement for numerical accuracy. The objective of this exercise was to provide the engineering and scientific community with a common reference point for the evaluation of commercial CFD codes.

Freitas, C.J. [Southwest Research Inst., San Antonio, TX (United States). Computational Mechanics Section

1995-06-01

213

Heat-pipe Earth.  

PubMed

The heat transport and lithospheric dynamics of early Earth are currently explained by plate tectonic and vertical tectonic models, but these do not offer a global synthesis consistent with the geologic record. Here we use numerical simulations and comparison with the geologic record to explore a heat-pipe model in which volcanism dominates surface heat transport. These simulations indicate that a cold and thick lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downwards. Declining heat sources over time led to an abrupt transition to plate tectonics. Consistent with model predictions, the geologic record shows rapid volcanic resurfacing, contractional deformation, a low geothermal gradient across the bulk of the lithosphere and a rapid decrease in heat-pipe volcanism after initiation of plate tectonics. The heat-pipe Earth model therefore offers a coherent geodynamic framework in which to explore the evolution of our planet before the onset of plate tectonics. PMID:24067709

Moore, William B; Webb, A Alexander G

2013-09-26

214

Comparison of two modeling approaches of eddy current industrial non-destructive testing of steel pipes  

NASA Astrophysics Data System (ADS)

In the framework of the COFREND working group "Eddy current modeling", a benchmark has been proposed by the Vallourec research center. This case corresponds to the modeling of an industrial online testing of seamless steel pipes by eddy current method with encircling coils. The centering of the steel pipe in the coil is not considered as perfect and a shift is imposed to the pipe. For this benchmark, the Vallourec research center (VRA, Vallourec Research Aulnoye) has compared two solutions with different approaches: the first one is based on semi-analytical methods through the CIVA software developed by the CEA, the second one on finite element method through the software Flux. Results for these two approaches are very similar between them and coherent to experimental data. It proves that these two simulations methods are valid and could be used as a complementary approach.

Trillon, Adrien; Deneuville, François; Reboud, Christophe; Foucher, Fabrice; Lesselier, Dominique; Maurice, Lea

2014-02-01

215

Benchmarking. A Guide for Educators.  

ERIC Educational Resources Information Center

This book offers strategies for enhancing a school's teaching and learning by using benchmarking, a team-research and data-driven process for increasing school effectiveness. Benchmarking enables professionals to study and know their systems and continually improve their practices. The book is designed to lead a team step by step through the…

Tucker, Sue

216

Former Yosemite Hydrologic Benchmark Streamgage  

USGS Multimedia Gallery

In this image, the former USGS Hydrologic Benchmark Streamgage on the Merced River in Yosemite Valley can be seen. Hydrologic Benchmark streamgages are those at which no human development exists upstream of the streamgage. The streamgage station has been in existence since 1915, and was replaced by ...

217

46 CFR 119.455 - Fuel piping.  

Code of Federal Regulations, 2013 CFR

...construction of fuel lines, including pipe, tube, and hose, must comply...piping of other materials, such as seamless steel pipe or tubing, which provide equivalent...installation of fuel lines, including pipe, tube, and hose, must...

2013-10-01

218

46 CFR 182.455 - Fuel piping.  

Code of Federal Regulations, 2014 CFR

...construction of fuel lines, including pipe, tube, and hose, must comply...piping of other materials, such as seamless steel pipe or tubing, which provide equivalent...installation of fuel lines, including pipe, tube, and hose, must...

2014-10-01

219

46 CFR 182.455 - Fuel piping.  

Code of Federal Regulations, 2013 CFR

...construction of fuel lines, including pipe, tube, and hose, must comply...piping of other materials, such as seamless steel pipe or tubing, which provide equivalent...installation of fuel lines, including pipe, tube, and hose, must...

2013-10-01

220

46 CFR 119.455 - Fuel piping.  

Code of Federal Regulations, 2011 CFR

...construction of fuel lines, including pipe, tube, and hose, must comply...piping of other materials, such as seamless steel pipe or tubing, which provide equivalent...installation of fuel lines, including pipe, tube, and hose, must...

2011-10-01

221

46 CFR 119.455 - Fuel piping.  

Code of Federal Regulations, 2010 CFR

...construction of fuel lines, including pipe, tube, and hose, must comply...piping of other materials, such as seamless steel pipe or tubing, which provide equivalent...installation of fuel lines, including pipe, tube, and hose, must...

2010-10-01

222

46 CFR 119.455 - Fuel piping.  

Code of Federal Regulations, 2012 CFR

...construction of fuel lines, including pipe, tube, and hose, must comply...piping of other materials, such as seamless steel pipe or tubing, which provide equivalent...installation of fuel lines, including pipe, tube, and hose, must...

2012-10-01

223

46 CFR 119.455 - Fuel piping.  

Code of Federal Regulations, 2014 CFR

...construction of fuel lines, including pipe, tube, and hose, must comply...piping of other materials, such as seamless steel pipe or tubing, which provide equivalent...installation of fuel lines, including pipe, tube, and hose, must...

2014-10-01

224

Apparatus for moving a pipe inspection probe through piping  

DOEpatents

A method and apparatus for controllably moving devices for cleaning or inspection through piping systems, including piping systems with numerous piping bends therein, by using hydrostatic pressure of a working fluid introduced into the piping system. The apparatus comprises a reservoir or other source for supplying the working fluid to the piping system, a launch tube for admitting the device into the launcher and a reversible, positive displacement pump for controlling the direction and flow rate of the working fluid. The device introduced into the piping system moves with the flow of the working fluid through the piping system. The launcher attaches to the valved ends of a piping system so that fluids in the piping system can recirculate in a closed loop. The method comprises attaching the launcher to the piping system, supplying the launcher with working fluid, admitting the device into the launcher, pumping the working fluid in the direction and at the rate desired so that the device moves through the piping system for pipe cleaning or inspection, removing the device from the launcher, and collecting the working fluid contained in the launcher.

Zollinger, W. Thor (Martinez, GA); Appel, D. Keith (Aiken, SC); Lewis, Gregory W. (North Augusta, SC)

1995-01-01

225

Apparatus for moving a pipe inspection probe through piping  

DOEpatents

A method and apparatus are disclosed for controllably moving devices for cleaning or inspection through piping systems, including piping systems with numerous piping bends therein, by using hydrostatic pressure of a working fluid introduced into the piping system. The apparatus comprises a reservoir or other source for supplying the working fluid to the piping system, a launch tube for admitting the device into the launcher and a reversible, positive displacement pump for controlling the direction and flow rate of the working fluid. The device introduced into the piping system moves with the flow of the working fluid through the piping system. The launcher attaches to the valved ends of a piping system so that fluids in the piping system can recirculate in a closed loop. The method comprises attaching the launcher to the piping system, supplying the launcher with working fluid, admitting the device into the launcher, pumping the working fluid in the direction and at the rate desired so that the device moves through the piping system for pipe cleaning or inspection, removing the device from the launcher, and collecting the working fluid contained in the launcher. 8 figs.

Zollinger, W.T.; Appel, D.K.; Lewis, G.W.

1995-07-18

226

Heat pipe cooled probe  

NASA Technical Reports Server (NTRS)

The basic heat pipe principle is employed to provide a self-contained passively cooled probe that may be placed into a high temperature environment. The probe consists of an evaporator region of a heat pipe and a sensing instrument. Heat is absorbed as the working fluid evaporates in the probe. The vapor is transported to the vapor space of the condenser region. Heat is dissipated from the condenser region and fins causing condensation of the working fluid, which returns to the probe by gravity and the capillary action of the wick. Working fluid, wick and condenser configurations and structure materials can be selected to maintain the probe within an acceptable temperature range.

Camarda, C. J. (inventor); Couch, L. M.

1984-01-01

227

Tippy Tap Plus Piping  

NSDL National Science Digital Library

The Tippy Tap hand-washing station is an inexpensive and effective device used extensively in the developing world. One shortcoming of the homemade device is that it must be manually refilled with water and therefore is of limited use in high-traffic areas. In this activity, student teams design, prototype and test piping systems to transport water from a storage tank to an existing Tippy Tap hand-washing station, thereby creating a more efficient hand-washing station. Through this example service-learning engineering project, students learn basic fluid dynamic principles that are needed for creating efficient piping systems.

Integrated Teaching and Learning Program, College of Engineering, University of Colorado at Boulder,

228

Heat transfer in pipes  

NASA Technical Reports Server (NTRS)

The heat transfer from hot water to a cold copper pipe in laminar and turbulent flow condition is determined. The mean flow through velocity in the pipe, relative test length and initial temperature in the vessel were varied extensively during tests. Measurements confirm Nusselt's theory for large test lengths in laminar range. A new equation is derived for heat transfer for large starting lengths which agrees satisfactorily with measurements for large starting lengths. Test results are compared with the new Prandtl equation for heat transfer and correlated well. Test material for 200- and to 400-diameter test length is represented at four different vessel temperatures.

Burbach, T.

1985-01-01

229

NAS Grid Benchmarks: A Tool for Grid Space Exploration  

NASA Technical Reports Server (NTRS)

We present an approach for benchmarking services provided by computational Grids. It is based on the NAS Parallel Benchmarks (NPB) and is called NAS Grid Benchmark (NGB) in this paper. We present NGB as a data flow graph encapsulating an instance of an NPB code in each graph node, which communicates with other nodes by sending/receiving initialization data. These nodes may be mapped to the same or different Grid machines. Like NPB, NGB will specify several different classes (problem sizes). NGB also specifies the generic Grid services sufficient for running the bench-mark. The implementor has the freedom to choose any specific Grid environment. However, we describe a reference implementation in Java, and present some scenarios for using NGB.

Frumkin, Michael; VanderWijngaart, Rob F.; Biegel, Bryan (Technical Monitor)

2001-01-01

230

Benchmarking Parallel Java Master's Project Report  

E-print Network

Benchmarking Parallel Java Master's Project Report Asma'u Sani Mohammed Java API by implementing the OpenMP version of the NAS Parallel Benchmark (NPB in comparison with FORTRAN OpenMP. Benchmarking Parallel Java allows us to understand

Kaminsky, Alan

231

Heat pipe array heat exchanger  

DOEpatents

A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

Reimann, Robert C. (Lafayette, NY)

1987-08-25

232

Aircraft Engine Gas Path Diagnostic Methods: Public Benchmarking Results  

NASA Technical Reports Server (NTRS)

Recent technology reviews have identified the need for objective assessments of aircraft engine health management (EHM) technologies. To help address this issue, a gas path diagnostic benchmark problem has been created and made publicly available. This software tool, referred to as the Propulsion Diagnostic Method Evaluation Strategy (ProDiMES), has been constructed based on feedback provided by the aircraft EHM community. It provides a standard benchmark problem enabling users to develop, evaluate and compare diagnostic methods. This paper will present an overview of ProDiMES along with a description of four gas path diagnostic methods developed and applied to the problem. These methods, which include analytical and empirical diagnostic techniques, will be described and associated blind-test-case metric results will be presented and compared. Lessons learned along with recommendations for improving the public benchmarking processes will also be presented and discussed.

Simon, Donald L.; Borguet, Sebastien; Leonard, Olivier; Zhang, Xiaodong (Frank)

2013-01-01

233

Benchmarking foreign electronics technologies  

SciTech Connect

This report has been drafted in response to a request from the Japanese Technology Evaluation Center`s (JTEC) Panel on Benchmarking Select Technologies. Since April 1991, the Competitive Semiconductor Manufacturing (CSM) Program at the University of California at Berkeley has been engaged in a detailed study of quality, productivity, and competitiveness in semiconductor manufacturing worldwide. The program is a joint activity of the College of Engineering, the Haas School of Business, and the Berkeley Roundtable on the International Economy, under sponsorship of the Alfred P. Sloan Foundation, and with the cooperation of semiconductor producers from Asia, Europe and the United States. Professors David A. Hodges and Robert C. Leachman are the project`s Co-Directors. The present report for JTEC is primarily based on data and analysis drawn from that continuing program. The CSM program is being conducted by faculty, graduate students and research staff from UC Berkeley`s Schools of Engineering and Business, and Department of Economics. Many of the participating firms are represented on the program`s Industry Advisory Board. The Board played an important role in defining the research agenda. A pilot study was conducted in 1991 with the cooperation of three semiconductor plants. The research plan and survey documents were thereby refined. The main phase of the CSM benchmarking study began in mid-1992 and will continue at least through 1997. reports are presented on the manufacture of integrated circuits; data storage; wireless technology; human-machine interfaces; and optoelectronics. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

Bostian, C.W.; Hodges, D.A.; Leachman, R.C.; Sheridan, T.B.; Tsang, W.T.; White, R.M.

1994-12-01

234

Heat Pipe With Interrupted Slot  

NASA Technical Reports Server (NTRS)

Newer version of heat pipe slot interrupted by plug or, if heat pipe is cast, by bridge of heat-pipe material cast integrally across groove. Small barrier assists in priming heat pipe. Vapor and noncondensible gas still accumulates in liquid channel at evaporator before or during startup, but barrier keeps liquid out of small part of slot at bubble. Dry part of slot allows bubble to escape into vapor channel, making room for liquid to move in during startup.

Brown, Richard F.; Kosson, Robert L.; Edelstein, Fred

1994-01-01

235

Reusable high-temperature heat pipes and heat pipe panels  

NASA Technical Reports Server (NTRS)

A reusable, durable heat pipe which is capable of operating at temperatures up to about 3000 F in an oxidizing environment and at temperatures above 3000 F in an inert or vacuum environment is produced by embedding a refractory metal pipe within a carbon-carbon composite structure. A reusable, durable heat pipe panel is made from an array of refractory-metal pipes spaced from each other. The reusable, durable, heat-pipe is employed to fabricate a hypersonic vehicle leading edge and nose cap.

Camarda, Charles J. (inventor); Ransone, Philip O. (inventor)

1989-01-01

236

Heat pipe investigations  

NASA Technical Reports Server (NTRS)

Techniques associated with thermal-vacuum and bench testing, along with flight testing of the OAO-C spacecraft heat pipes are outlined, to show that the processes used in heat transfer design and testing are adequate for good performance evaluations.

Marshburn, J. P.

1973-01-01

237

Aeronautical tubes and pipes  

NASA Astrophysics Data System (ADS)

The main and subcomponent French suppliers of aircraft tubes and pipes are discussed, and the state of the industry is analyzed. Quality control is essential for tubes with regard to their i.d. and metallurgical compositions. French regulations do not allow welded seam tubes in hydraulic circuits unless no other form is available, and then rustproofed steel must be installed. The actual low level of orders for any run of tubes dictates that the product is only one of several among the manufacturers' line. Automation, both in NDT and quality control, assures that the tubes meet specifications. A total of 10 French companies participate in the industry, serving both civil and military needs, with some companies specializing only in titanium, steel, or aluminum materials. Concerns wishing to enter the market must upgrade their equipment to meet the higher aeronautical specifications and be prepared to furnish tubes and pipes that serve both functional and structural purposes simultaneously. Additionally, pipe-bending machines must also perform to tight specifications. Pipes can range from 0.2 mm exterior diameter to 40 mm, with wall thicknesses from 0.02 mm to 3 mm. A chart containing a list of manufacturers and their respective specifications and characteristics is presented, and a downtrend in production with reduction of personnel is noted.

Beauclair, N.

1984-12-01

238

Heat pipe dynamic behavior  

Microsoft Academic Search

The vapor flow in a heat pipe was mathematically modeled and the equations governing the transient behavior of the core were solved numerically. The modeled vapor flow is transient, axisymmetric (or two-dimensional) compressible viscous flow in a closed chamber. The two methods of solution are described. The more promising method failed (a mixed Galerkin finite difference method) whereas a more

F. Issacci; G. L. Roche; D. B. Klein; I. Catton

1988-01-01

239

RIEMANN PROBLEMS WITH A KINK Helge Holden, Nils Henrik Risebro  

E-print Network

problem for isothermal flow of a gas in a thin pipe with a kink in it. This is modeled by a 2 \\Theta 2. We consider the flow of an isothermal gas in a (infinitely) long thin pipe of constant cross section. If the walls of the pipe have no effect on the flow, and the pipe is straight, this can be modeled

240

Using ductile iron pipe for penstocks: A new option  

SciTech Connect

When choosing the type of material for the penstock at a new project or when repairing or replacing pipe at existing plants, it may pay off to take a look at ductile iron pipe. This type of pipe was used at the Wailuku River hydro project, resulting in a more corrosion resistant, durable, and cost-effective penstock. This article reviews the planning and decision-making that went into this effort, including: (1) material properties, (2) testing, (3) performance under negative pressure conditions, (4) pressure rating, (5) corrosion resistance, (6) seismic effects, (7) installation problems, and (8) economic considerations.

Hurless, R.C. [Synergics Energy Development, Inc., Annapolis, MD (United States)

1996-04-01

241

Benchmarking in water project analysis  

NASA Astrophysics Data System (ADS)

The with/without principle of cost-benefit analysis is examined for the possible bias that it brings to water resource planning. Theory and examples for this question are established. Because benchmarking against the demonstrably low without-project hurdle can detract from economic welfare and can fail to promote efficient policy, improvement opportunities are investigated. In lieu of the traditional, without-project benchmark, a second-best-based "difference-making benchmark" is proposed. The project authorizations and modified review processes instituted by the U.S. Water Resources Development Act of 2007 may provide for renewed interest in these findings.

Griffin, Ronald C.

2008-11-01

242

California commercial building energy benchmarking  

SciTech Connect

Building energy benchmarking is the comparison of whole-building energy use relative to a set of similar buildings. It provides a useful starting point for individual energy audits and for targeting buildings for energy-saving measures in multiple-site audits. Benchmarking is of interest and practical use to a number of groups. Energy service companies and performance contractors communicate energy savings potential with ''typical'' and ''best-practice'' benchmarks while control companies and utilities can provide direct tracking of energy use and combine data from multiple buildings. Benchmarking is also useful in the design stage of a new building or retrofit to determine if a design is relatively efficient. Energy managers and building owners have an ongoing interest in comparing energy performance to others. Large corporations, schools, and government agencies with numerous facilities also use benchmarking methods to compare their buildings to each other. The primary goal of Task 2.1.1 Web-based Benchmarking was the development of a web-based benchmarking tool, dubbed Cal-Arch, for benchmarking energy use in California commercial buildings. While there were several other benchmarking tools available to California consumers prior to the development of Cal-Arch, there were none that were based solely on California data. Most available benchmarking information, including the Energy Star performance rating, were developed using DOE's Commercial Building Energy Consumption Survey (CBECS), which does not provide state-level data. Each database and tool has advantages as well as limitations, such as the number of buildings and the coverage by type, climate regions and end uses. There is considerable commercial interest in benchmarking because it provides an inexpensive method of screening buildings for tune-ups and retrofits. However, private companies who collect and manage consumption data are concerned that the identities of building owners might be revealed and hence are reluctant to share their data. The California Commercial End Use Survey (CEUS), the primary source of data for Cal-Arch, is a unique source of information on commercial buildings in California. It has not been made public; however, it was made available by CEC to LBNL for the purpose of developing a public benchmarking tool.

Kinney, Satkartar; Piette, Mary Ann

2003-07-01

243

Techniques associated with thermal-vacuum testing of the OAO C heat pipes  

NASA Technical Reports Server (NTRS)

The mechanical problems associated with the testing of two heat pipes installed in the OAO C spacecraft are described. The test problems discussed concern the specially designed heat removal devices, the mobile tilt table, the table position indicator, and the heat input machanisms. It was determined that the techniques used were adequate for thermal-vacuum testing of heat pipes.

Marshburn, J. P.

1972-01-01

244

Performance characteristics of gravity-assisted potassium heat pipes  

NASA Astrophysics Data System (ADS)

Experiments with potassium-stainless steel gravity-assisted heat pipes were performed. Performance limitations due to entrainment or flooding of the liquid return flow are compared with analytical model predictions. The effect of heated pool height was investigated, and problems with surface wetting are discussed. A comparison between entrainment limits for smoothand textured-walled heat pipes was made, and a minimum internal surface texturing depth is suggested.

Prenger, F. C.; Keddy, E. S.; Sena, J. T.

1986-08-01

245

Transient Anomalous Diffusion in Pipe Poiseuille Flow  

Microsoft Academic Search

In this paper we revisit the classical problem of dispersion of a point-discharge of tracer in laminar pipe Poiseuille flow. We show that in the limit of small non-dimensional diffusion, D, that tracer dispersion can be divided into three regimes. For small times (t << D-1\\/3),diffusion dominates advection yielding a roughly spherically symmetric dispersion cloud. At large times (t >>

Marco Latini; Andrew J. Bernoff

2000-01-01

246

Utilizing clad piping to improve process plant piping integrity, reliability, and operations  

SciTech Connect

During the past four years carbon steel piping clad with type 304L (UNS S30403) stainless steel has been used to solve the flow accelerated corrosion (FAC) problem in nuclear power plants with exceptional success. The product is designed to allow ``like for like`` replacement of damaged carbon steel components where the carbon steel remains the pressure boundary and type 304L (UNS S30403) stainless steel the corrosion allowance. More than 3000 feet of piping and 500 fittings in sizes from 6 to 36-in. NPS have been installed in the extraction steam and other lines of these power plants to improve reliability, eliminate inspection program, reduce O and M costs and provide operational benefits. This concept of utilizing clad piping in solving various corrosion problems in industrial and process plants by conservatively selecting a high alloy material as cladding can provide similar, significant benefits in controlling corrosion problems, minimizing maintenance cost, improving operation and reliability to control performance and risks in a highly cost effective manner. This paper will present various material combinations and applications that appear ideally suited for use of the clad piping components in process plants.

Chakravarti, B. [KLAD Inc., Naperville, IL (United States)

1996-07-01

247

Virtual machine performance benchmarking.  

PubMed

The attractions of virtual computing are many: reduced costs, reduced resources and simplified maintenance. Any one of these would be compelling for a medical imaging professional attempting to support a complex practice on limited resources in an era of ever tightened reimbursement. In particular, the ability to run multiple operating systems optimized for different tasks (computational image processing on Linux versus office tasks on Microsoft operating systems) on a single physical machine is compelling. However, there are also potential drawbacks. High performance requirements need to be carefully considered if they are to be executed in an environment where the running software has to execute through multiple layers of device drivers before reaching the real disk or network interface. Our lab has attempted to gain insight into the impact of virtualization on performance by benchmarking the following metrics on both physical and virtual platforms: local memory and disk bandwidth, network bandwidth, and integer and floating point performance. The virtual performance metrics are compared to baseline performance on "bare metal." The results are complex, and indeed somewhat surprising. PMID:21207096

Langer, Steve G; French, Todd

2011-10-01

248

Eddy currents benchmark analysis with COMSOL  

NASA Astrophysics Data System (ADS)

Several benchmark studies in eddy currents have been proposed by the WFNDEC. Also, there are many analytical exact and approximate solution of interest to quantitatively evaluate the capability of numerical codes to predict the magnitude of the induced currents effects. In this paper we present the results obtained using COMSOL for a representative set of cases of interest. We analyze the accuracy of the results, but also the elements we believe are relevant from the perspective of the NDE specialist (simplicity, computer requirements, things to take into account to get good results, problems faced when solving, failures, etc.).

Etcheverry, Javier I.; Ziella, Daniel H.

2014-02-01

249

Memory-intensive benchmarks: IRAM vs. cache-based machines  

SciTech Connect

The increasing gap between processor and memory performance has led to new architectural models for memory-intensive applications. In this paper, we explore the performance of a set of memory-intensive benchmarks and use them to compare the performance of conventional cache-based microprocessors to a mixed logic and DRAM processor called VIRAM. The benchmarks are based on problem statements, rather than specific implementations, and in each case we explore the fundamental hardware requirements of the problem, as well as alternative algorithms and data structures that can help expose fine-grained parallelism or simplify memory access patterns. The benchmarks are characterized by their memory access patterns, their basic structures, and the ratio of computation to memory operation.

Gaeke, Brian G.; Husbands, Parry; Kim, Hyun Jin; Li, Xiaoye S.; Moon, Hyun Jin; Oliker, Leonid; Yelick, Katherine A.; Biswas, Rupak

2001-09-29

250

Interpreting the Benchmark Comparisons Report  

E-print Network

are not included. Mean The mean is the weighted arithmetic average of student level benchmark scores. Bar ChartsInterpreting the Benchmark Comparisons Report Class Mean a Sig b Effect Size c Mean a Sig b Effect Size c Mean a Sig b Effect Size c First-Year 51.6 .05 50.4 * .14 51.8 .04 Senior 55.9 -.01 55.6 .02 55

Rhode Island, University of

251

Benchmarking hypercube hardware and software  

NASA Technical Reports Server (NTRS)

It was long a truism in computer systems design that balanced systems achieve the best performance. Message passing parallel processors are no different. To quantify the balance of a hypercube design, an experimental methodology was developed and the associated suite of benchmarks was applied to several existing hypercubes. The benchmark suite includes tests of both processor speed in the absence of internode communication and message transmission speed as a function of communication patterns.

Grunwald, Dirk C.; Reed, Daniel A.

1986-01-01

252

Randomized Benchmarking of Clifford Operators  

NASA Astrophysics Data System (ADS)

Randomized benchmarking is an experimental procedure intended to demonstrate control of quantum systems. The procedure extracts the average error introduced by a set of control operations. When the target set of operations is intended to be the set of Clifford operators, the randomized benchmarking algorithm is particularly easy to perform and its results have an important interpretation with respect to quantum computation. The aim of the benchmark is to provide a simple, useful parameter describing the quality of quantum control with an experiment that can be performed in a standard way on any prospective quantum computer. This parameter can be used to fairly compare different experiments or to mark improvement in a single experiment. In this thesis I discuss first the original randomized-benchmarking procedure and the importance of the Clifford operators for its implementation. I develop the statistical analysis of the results and the physical assumptions that are required for the simplest analysis to apply. The original procedure does not extend in an obvious way to benchmarking of more than one qubit, so I introduce a standardized procedure for randomized benchmarking that applies to any number of qubits. This new procedure also enables the benchmarking of an individual control operation. I describe two randomized-benchmarking experiments I helped to design: one involved a single qubit and utilized a variation of the original procedure and the second involved two qubits and demonstrated the new procedure. I conclude with several potential extensions to the original and new procedures that give them reduced experimental overhead, the ability to describe encoded operations, and fairer comparisons between experiments.

Meier, A. M.

253

Benchmarking Small Business Performance: Barriers and Benefits  

Microsoft Academic Search

Abstract Benchmarking,is now ,a commonplace ,term in business ,and many ,definitions have been proposed. Despite its increasing popularity there is growing ,evidence that it is often used incorrectly. ‘Benchmarking’ seems to be confused with competitive comparison studies, which are simply a component part of benchmarking. This paper reviews previous benchmarking studies in general, identifying the background to its growth, and

Sue Bergin

254

Commbench - a telecommunication benchmark for network processors  

Microsoft Academic Search

Abstract This paper presents a benchmark, CommBench, for use in evaluating and designing telecommunications network processors. The benchmark applications focus on small, computationally intense program kernels typical of the network processor environment. The benchmark is composed of eight programs, four of them oriented towards packet header processing and four oriented towards data stream processing. The benchmark is dened,and various characteristics

T. Wolf; M. Franklin

2000-01-01

255

NHT-1 I/O Benchmarks  

NASA Technical Reports Server (NTRS)

The NHT-1 benchmarks am a set of three scalable I/0 benchmarks suitable for evaluating the I/0 subsystems of high performance distributed memory computer systems. The benchmarks test application I/0, maximum sustained disk I/0, and maximum sustained network I/0. Sample codes are available which implement the benchmarks.

Carter, Russell; Ciotti, Bob; Fineberg, Sam; Nitzbert, Bill

1992-01-01

256

Benchmarking for the Learning and Skills Sector.  

ERIC Educational Resources Information Center

This document is designed to introduce practitioners in the United Kingdom's learning and skills sector to the principles and practice of benchmarking. The first section defines benchmarking and differentiates metric, diagnostic, and process benchmarking. The remainder of the booklet details the following steps of the benchmarking process: (1) get…

Owen, Jane

257

Instability in pipe flow  

PubMed Central

The long-puzzling, unphysical result that linear stability analyses lead to no transition in pipe flow, even at infinite Reynolds number, is ascribed to the use of stick boundary conditions, because they ignore the amplitude variations associated with the roughness of the wall. Once that length scale is introduced (here, crudely, through a corrugated pipe), linear stability analyses lead to stable vortex formation at low Reynolds number above a finite amplitude of the corrugation and unsteady flow at a higher Reynolds number, where indications are that the vortex dislodges. Remarkably, extrapolation to infinite Reynolds number of both of these transitions leads to a finite and nearly identical value of the amplitude, implying that below this amplitude, the vortex cannot form because the wall is too smooth and, hence, stick boundary results prevail. PMID:18178623

Cotrell, D. L.; McFadden, G. B.; Alder, B. J.

2008-01-01

258

Performance of NAS parallel application-benchmarks on IBM SP1  

Microsoft Academic Search

We present the performance of three application benchmarks (BT, LU, and SP) from the NAS Parallel Benchmark suite on the IBM scalable POWERparallel 1 (SP1) system. We present performance results on both Class A and Class B problem sets. We compare the performance of two communication protocols, MPL and MPL\\/p, and also present results on a cluster of workstations called

Vijay K. Naik

1994-01-01

259

Using Premia and Nsp for Constructing a Risk Management Benchmark for Testing Parallel  

E-print Network

Using Premia and Nsp for Constructing a Risk Management Benchmark for Testing Parallel Architecture useful for benchmarking (software/hardware) parallel architectures. Unfortunately, in our knowledge problems on a cluster. This unified framework can then be used to test different parallel architectures. 1

260

Benchmarking Intelligent Service Robots through Scientific Competitions: the RoboCup@Home approach  

E-print Network

implemented test is the most important outcome of RoboCup@Home, namely the benchmarking of robot cognition and service robots that addresses the previ- ously mentioned problems. In particular, this methodologyBenchmarking Intelligent Service Robots through Scientific Competitions: the RoboCup@Home approach

Behnke, Sven

261

Benchmarks for GADRAS performance validation.  

SciTech Connect

The performance of the Gamma Detector Response and Analysis Software (GADRAS) was validated by comparing GADRAS model results to experimental measurements for a series of benchmark sources. Sources for the benchmark include a plutonium metal sphere, bare and shielded in polyethylene, plutonium oxide in cans, a highly enriched uranium sphere, bare and shielded in polyethylene, a depleted uranium shell and spheres, and a natural uranium sphere. The benchmark experimental data were previously acquired and consist of careful collection of background and calibration source spectra along with the source spectra. The calibration data were fit with GADRAS to determine response functions for the detector in each experiment. A one-dimensional model (pie chart) was constructed for each source based on the dimensions of the benchmark source. The GADRAS code made a forward calculation from each model to predict the radiation spectrum for the detector used in the benchmark experiment. The comparisons between the GADRAS calculation and the experimental measurements are excellent, validating that GADRAS can correctly predict the radiation spectra for these well-defined benchmark sources.

Mattingly, John K.; Mitchell, Dean James; Rhykerd, Charles L., Jr.

2009-09-01

262

NAFEMS Finite Element Benchmarks for MDG Code Verification  

SciTech Connect

NAFEMS was originally founded at the United Kingdom's National Engineering Laboratory as the National Agency for Finite Element Methods and Standards. It was subsequently privatized as the not-for-profit organization NAFEMS, Ltd., but retains its mission ''To promote the safe and reliable use of finite element and related technology''. That mission has been pursued in part by sponsoring a series of studies that published benchmarked deemed suitable to assess the basic accuracy of engineering simulation tools. The early studies focused on FEA for linear solid and structural mechanics and then extended to nonlinear solid mechanics, eventually including contact. These benchmarks are complemented by educational materials concerning analysis technologies and approaches. More recently NAFEMS is expanding to consider thermal-fluid problems. Further information is available at www.nafems.org. Essentially all major commercial firms selling FEA for solid mechanics are members of NAFEMS and it seemed clear that Methods Development Group should leverage from this information resource, too. In 2002, W Program ASCI funding purchased a three-year membership in NAFEMS. In the summer of 2003 the first author hosted a summer graduate student to begin modeling some of the benchmark problems. We concentrated on NIKE3D, as the benchmarks are most typically problems most naturally run with implicit FEA. Also, this was viewed as a natural path to generate verification problems that could be subsequently incorporated into the Diablo code's test suite. This report documents and archives our initial efforts. The intent is that this will be a ''living document'' that can be expanded as further benchmarks are generated, run, interpreted and documented. To this end each benchmark, or related grouping, is localized in its own section with its own pagination. Authorship (test engineers) will be listed section by section.

Greer, R; Ferencz, R M

2004-02-24

263

Guidable pipe plug  

DOEpatents

A plugging device for closing an opening defined by an end of a pipe with sealant comprises a cap, an extension, an inner seal, a guide, and at least one stop. The cap has an inner surface which defines a chamber adapted for retaining the sealant. The chamber is dimensioned slightly larger than the end so as to receive the end. The chamber and end define a gap therebetween. The extension has a distal end and is attached to the inner surface opposite the distal end. The inner seal is attached to the extension and sized larger than the opening. The guide is positioned forward of the inner seal and attached to the distal end. The guide is also dimensioned to be inserted into the opening. The stop is attached to the extender, and when the stop is disposed in the pipe, the stop is movable with respect to the conduit in one direction and also prevents misalignment of the cap with the pipe. A handle can also be included to allow the cap to be positioned robotically.

Glassell, Richard L. (Knoxville, TN); Babcock, Scott M. (Farragut, TN); Lewis, Benjamin E. (Farragut, TN)

2001-01-01

264

Implementation of Benchmarking Transportation Logistics Practices and Future Benchmarking Organizations  

SciTech Connect

The purpose of the Office of Civilian Radioactive Waste Management's (OCRWM) Logistics Benchmarking Project is to identify established government and industry practices for the safe transportation of hazardous materials which can serve as a yardstick for design and operation of OCRWM's national transportation system for shipping spent nuclear fuel and high-level radioactive waste to the proposed repository at Yucca Mountain, Nevada. The project will present logistics and transportation practices and develop implementation recommendations for adaptation by the national transportation system. This paper will describe the process used to perform the initial benchmarking study, highlight interim findings, and explain how these findings are being implemented. It will also provide an overview of the next phase of benchmarking studies. The benchmarking effort will remain a high-priority activity throughout the planning and operational phases of the transportation system. The initial phase of the project focused on government transportation programs to identify those practices which are most clearly applicable to OCRWM. These Federal programs have decades of safe transportation experience, strive for excellence in operations, and implement effective stakeholder involvement, all of which parallel OCRWM's transportation mission and vision. The initial benchmarking project focused on four business processes that are critical to OCRWM's mission success, and can be incorporated into OCRWM planning and preparation in the near term. The processes examined were: transportation business model, contract management/out-sourcing, stakeholder relations, and contingency planning. More recently, OCRWM examined logistics operations of AREVA NC's Business Unit Logistics in France. The next phase of benchmarking will focus on integrated domestic and international commercial radioactive logistic operations. The prospective companies represent large scale shippers and have vast experience in safely and efficiently shipping spent nuclear fuel and other radioactive materials. Additional business processes may be examined in this phase. The findings of these benchmarking efforts will help determine the organizational structure and requirements of the national transportation system. (authors)

Thrower, A.W. [U.S. Department of Energy, Office of Civilian Radioactive Waste Management, Washington, DC (United States); Patric, J. [Booz Allen Hamilton, Washington, DC (United States); Keister, M. [Idaho National Laboratory, Idaho Falls, ID (United States)

2008-07-01

265

Correlational Effect Size Benchmarks.  

PubMed

Effect size information is essential for the scientific enterprise and plays an increasingly central role in the scientific process. We extracted 147,328 correlations and developed a hierarchical taxonomy of variables reported in Journal of Applied Psychology and Personnel Psychology from 1980 to 2010 to produce empirical effect size benchmarks at the omnibus level, for 20 common research domains, and for an even finer grained level of generality. Results indicate that the usual interpretation and classification of effect sizes as small, medium, and large bear almost no resemblance to findings in the field, because distributions of effect sizes exhibit tertile partitions at values approximately one-half to one-third those intuited by Cohen (1988). Our results offer information that can be used for research planning and design purposes, such as producing better informed non-nil hypotheses and estimating statistical power and planning sample size accordingly. We also offer information useful for understanding the relative importance of the effect sizes found in a particular study in relationship to others and which research domains have advanced more or less, given that larger effect sizes indicate a better understanding of a phenomenon. Also, our study offers information about research domains for which the investigation of moderating effects may be more fruitful and provide information that is likely to facilitate the implementation of Bayesian analysis. Finally, our study offers information that practitioners can use to evaluate the relative effectiveness of various types of interventions. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:25314367

Bosco, Frank A; Aguinis, Herman; Singh, Kulraj; Field, James G; Pierce, Charles A

2014-10-13

266

Pipe inspection using the pipe crawler. Innovative technology summary report  

SciTech Connect

The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned.

NONE

1999-05-01

267

Evaluation of the HPC Challenge Benchmarks in Virtualized Environments  

E-print Network

of the High Performance Linpack (HPL) benchmark used in the TOP500 list. The tests include four local (matrix-matrix multiply, STREAM, RandomAc- cess and FFT) and four global (High Performance Linpack ­ HPL, paral- lel of problem sizes. As expected, the HPL results had some overhead in all the virtual environments

Dongarra, Jack

268

Heat pipe technology: A bibliography with abstracts  

NASA Technical Reports Server (NTRS)

The annual supplement on heat pipe technology for 1971 is presented. The document contains 101 references with abstracts and 47 patents. The subjects discussed are: (1) heat pipe applications, (2) heat pipe theory, (3) design, development, and fabrication of heat pipes, (4) testing and operation, (5) subject and author index, and (6) heat pipe related patents.

1971-01-01

269

Insulating Cryogenic Pipes With Frost  

NASA Technical Reports Server (NTRS)

Crystallized water vapor fills voids in pipe insulation. Small, carefully controlled amount of water vapor introduced into dry nitrogen gas before it enters aft fuselage. Vapor freezes on pipes, filling cracks in insulation. Ice prevents gaseous nitrogen from condensing on pipes and dripping on structure, in addition to helping to insulate all parts. Industrial applications include large refrigeration plants or facilities that use cryogenic liquids.

Stephenson, J. G.; Bova, J. A.

1985-01-01

270

Radiation crosslinked plasticized PVC - pipes  

NASA Astrophysics Data System (ADS)

The efficiency of polyfunctional monomers triallyl cyanurate, allyl methacrylate, diallyl phtalate, 2-ethyl-2(hydroxy-methyl)-propanediol-(1,3) trimethacrylate, divinyl benzene and ethylene glycol dimethacrylate in radiation crosslinking of PVC was investigated. Patterns of pipes were produced and irradiated with gamma rays. The resistance to internal pressure of crosslinked PVC pipes was measured at 80°C and compared with resistance of unirradiated PVC pipes.

Hell, Z.; Ravli?, M.; Bogdanovi?, Lj.; Maleš, J.; Dvornik, I.; Ranogajec, F.; Ranogajec, M.; Tudori?-Ghemo, J.

271

Numerical heat-pipe modeling  

Microsoft Academic Search

The research described in this paper was conducted to better understand numerical modeling of heat-pipe transients. In the numerical model, the vapor flow was assumed to be unsteady, compressible and one-dimensional, while the one-dimensional, unsteady, heat diffusion equation was used to model energy conduction through the heat-pipe wall. The liquid return process in the heat-pipe wick was not modeled. Finite

Jerry Bowman; Richard W. Sweeten

1989-01-01

272

Coupling analysis of fluid-structure interaction in fluid-filled elbow pipe  

NASA Astrophysics Data System (ADS)

Fluid in the ship pipeline, due to power equipment components (such as impellers, plungers, etc.) and valves, will induce turbulence, cavitations, which generate high-frequency vibration excitation lines. The measurements results show that fluid-induced vibration of the pipeline is not only confined to the pipeline, but also have an impact on the hull structure. Pipe vibration due to transient flow is very common in marine pipe system Thus fluid-structure interaction problems in shipping lines is being paid more and more attention. In this paper, the fluid-filled elbow pipe is simulated considering fluid-structure interaction (FSI) by the software ADINA. And the simulation results are validated through comparison with results obtained by other numerical solution. The results show that FSI affects the pipe-filled-water modal frequencies seriously, but have little effects on pipe vibration shapes, and the free vibration frequency of the fluid-filled pipe is lower than that of empty pipe. The pipe vibration amplitude and effective stress caused by fluid increase as the fluid velocity increase. Pipe continues vibrating after fluid velocity is steady, and the vibration is dispersing as time increase. The protection against vibration near the elbow is important because the maximum pipe deformation caused by fluid near the elbow. The maximum effective stress increases from 0 to 1.4MPa due to the fluid velocity increases from 0 to 20m/s in 5 seconds. So it is necessary to consider the FSI for fluid-filled pipe.

Xu, W. W.; Wu, D. Z.; Wang, L. Q.

2012-11-01

273

Thermostructural applications of heat pipes  

NASA Technical Reports Server (NTRS)

The feasibility of integrating heat pipes in high temperature structure to reduce local hot spot temperature was evaluated for a variety of hypersonic aerospace vehicles. From an initial list of twenty-two potential applications, the single stage to orbit wing leading edge showed the greatest promise and was selected for preliminary design of an integrated heat pipe thermostructural system. The design consisted of a Hastelloy X assembly with sodium heat pipe passages aligned normal to the wing leading edge. A d-shaped heat pipe cross section was determined to be optimum from the standpoint of structural weight.

Peeples, M. E.; Reeder, J. C.; Sontag, K. E.

1979-01-01

274

Evaluation of Corrosion in Carbon Steel Pipes by Laser-Generated Guided Wave  

Microsoft Academic Search

\\u000a The objective of this research is to locate and evaluate wall thinning in pipe elbow by a non-contact guided wave technique\\u000a with laser source as a transmitter and air-bone transducer as a receiver, respectively. Wall thinning of carbon steel pipe\\u000a is one of the most serious problems in nuclear industry; especially the one in carbon steel pipe elbow caused by

Do-Youn Kim; Joon-Hyun Lee; Younho Cho; Jaesun Lee; Jan D. Achenbach

275

Heat Pipe Impact on Dehumidification, Indoor Air Quality and Energy Savings  

E-print Network

exist. In 1897, Perkins pipes - gravitational flow, heat pipes v the bread making industry. R. in 1942, was the first to propo pipes be used in refrigeration. since the mid 1960's, has used 1 aerospace applications for en management ranging from..., in time, create health, environmental and maintenance problems. The increased moisture promotes mold, mildew, bacteria, spores and viruses in the air which make people sick; supply registers rust and drip with condensation, wall paper peels off...

Cooper, J. T.

1996-01-01

276

Procedures for measuring the properties of heat-pipe wick materials  

SciTech Connect

Accurate measurements of wick properties must be available to design high-performance beat pipes and to properly interpret results from heat pipe tests. In a program that is aimed at developing heat-pipe receivers for solar-Stirling electric systems, we have recently explored procedures to measure the effective pore radius and permeability of wick materials in their final ``as fabricated`` condition. Measurement techniques are compared in this paper and problems that are frequently encountered in measuring wick properties are discussed.

Adkins, D.R.; Dykhuizen, R.C.

1993-07-01

277

Benchmarking of finite element codes for radioactive material transportation packages  

SciTech Connect

The increased power of computers and computer codes makes the use of nonlinear dynamic finite element analyses attractive for use as a tool used in the design and certification of radioactive material transportation packages. For this analysis technique to be acceptable it must be demonstrated. The technique has the ability to accurately capture the response of the packages to accident environments required by the regulations. The best method of demonstrating this ability is via a series of benchmark analyses. In this paper three benchmark problems involving significant inelastic deformations will be discussed. One of the problems has been analyzed using many different finite element codes. The other two problems involve comparison of finite element calculations to the results form physical tests. The ability of the finite element method to accurately capture the response in these three problems indicates the method should be acceptable for radioactive material transportation package design and certification.

Ammerman, D.J.

1996-10-01

278

Polymeric heat pipe wick  

NASA Technical Reports Server (NTRS)

A wick for use in a capillary loop pump heat pipe is described. The wick material is an essentially uniformly porous, permeable, open-cell, polyethylene thermoplastic foam having an ultrahigh average molecular weight of from approximately 1 to 5 million, and an average pore size of about 10 to 12 microns. A representative material having these characteristics is POREX UF, which has an average molecular weight of about 3 million. This material is fully compatible with the FREONs and anhydrous ammonia and allows for the use of these very efficient working fluids in capillary loops.

Seidenberg, Benjamin

1988-01-01

279

Intermediate Temperature Fluids for Heat Pipes and Loop Heat Pipes  

Microsoft Academic Search

Potential working fluids for heat pipes and loop heat pipes include water, organic fluids, elements, and halides. The paper surveys life tests conducted with 30 different intermediate temperature working fluids, and over 60 different working fluid\\/envelope combinations. Life tests have been run with three elemental working fluids: sulfur, sulfur-iodine mixtures, and mercury. Other fluids offer benefits over these three liquids

William G. Anderson; John R. Hartenstine; David B. Sarraf; Calin Tarau

280

Vapor spill pipe monitor  

DOEpatents

The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote ir gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote ir sensor which measures the gas composition.

Bianchini, G.M.; McRae, T.G.

1983-06-23

281

Building a Copper Pipe "Xylophone."  

ERIC Educational Resources Information Center

Explains how to use the equation for frequency of vibration of a transversely oscillating bar or pipe with both ends free to vibrate to build a simple and inexpensive xylophone from a 3-meter section of copper pipe. The instrument produces a full major scale and can be used to investigate various musical intervals. (Author/NB)

Lapp, David R.

2003-01-01

282

Heat pipe transient response approximation  

Microsoft Academic Search

A simple and concise routine that approximates the response of an alkali metal heat pipe to changes in evaporator heat transfer rate is described. This analytically based routine is compared with data from a cylindrical heat pipe with a crescent-annular wick that undergoes gradual (quasi-steady) transitions through the viscous and condenser boundary heat transfer limits. The sonic heat transfer limit

2001-01-01

283

Heat pipe transient response approximation  

Microsoft Academic Search

A simple and concise routine that approximates the response of an alkali metal heat pipe to changes in evaporator heat transfer rate is described. This analytically based routine is compared with data from a cylindrical heat pipe with a crescent-annular wick that undergoes gradual (quasi-steady) transitions through the viscous and condenser boundary heat transfer limits. The sonic heat transfer limit

Robert S. Reid

2002-01-01

284

Heat Pipe Blocks Return Flow  

NASA Technical Reports Server (NTRS)

Metal-foil reed valve in conventional slab-wick heat pipe limits heat flow to one direction only. With sink warmer than source, reed is forced closed and fluid returns to source side through annular transfer wick. When this occurs, wick slab on sink side of valve dries out and heat pipe ceases to conduct heat.

Eninger, J. E.

1982-01-01

285

Turbulence Transition in Pipe Flow  

Microsoft Academic Search

Pipe flow is a prominent example among the shear flows that undergo transition to turbulence without mediation by a linear instability of the laminar profile. Experiments on pipe flow, as well as plane Couette and plane Poiseuille flow, show that triggering turbulence depends sensitively on initial conditions, that between the laminar and the turbulent states there exists no intermediate state

Bruno Eckhardt; Tobias M. Schneider; Bjorn Hof; Jerry Westerweel

2007-01-01

286

Vibration analysis methods for piping  

Microsoft Academic Search

Attention is given to flow vibrations in pipe flow induced by singularity points in the piping system. The types of pressure fluctuations induced by flow singularities are examined, including the intense wideband fluctuations immediately downstream of the singularity and the acoustic fluctuations encountered in the remainder of the circuit, and a theory of noise generation by unsteady flow in internal

R. J. Gibert

1981-01-01

287

Alternate high capacity heat pipe  

NASA Technical Reports Server (NTRS)

The performance predictions for a fifty foot heat pipe (4 foot evaporator - 46 foot condensor) are discussed. These performance predictions are supported by experimental data for a four foot heat pipe. Both heat pipes have evaporators with axial groove wick structures and condensers with powder metal external artery wick structures. The predicted performance of a rectangular axial groove/external artery heat pipe operating in space is given. Heat transport versus groove width is plotted for 100, 200 and 300 grooves in the evaporator. The curves show that maximum power is achieved for groove widths from 0.040 to 0.053 as the number of grooves varies from 300 to 100. The corresponding range of maximum power is 3150 to 2400 watts. The relationships between groove width and heat pipe evaporate diameter for 100, 200 and 300 grooves in the evaporator are given. A four foot heat pipe having a three foot condenser and one foot evaporator was built and tested. The evaporator wick structure used axial grooves with rectangular cross sections, and the condenser wick structure used powder metal with an external artery configuration. Fabrication drawings are enclosed. The predicted and measured performance for this heat pipe is shown. The agreement between predicted and measured performance is good and therefore substantiates the predicted performance for a fifty foot heat pipe.

Voss, F. E.

1986-01-01

288

Flexible ultrasonic pipe inspection apparatus  

DOEpatents

A flexible, modular ultrasonic pipe inspection apparatus, comprising a flexible, hollow shaft that carries a plurality of modules, including at least one rotatable ultrasonic transducer, a motor/gear unit, and a position/signal encoder. The modules are connected by flexible knuckle joints that allow each module of the apparatus to change its relative orientation with respect to a neighboring module, while the shaft protects electrical wiring from kinking or buckling while the apparatus moves around a tight corner. The apparatus is moved through a pipe by any suitable means, including a tether or drawstring attached to the nose or tail, differential hydraulic pressure, or a pipe pig. The rotational speed of the ultrasonic transducer and the forward velocity of the apparatus are coordinated so that the beam sweeps out the entire interior surface of the pipe, enabling the operator to accurately assess the condition of the pipe wall and determine whether or not leak-prone corrosion damage is present.

Jenkins, Charles F. (Aiken, SC); Howard, Boyd D. (Augusta, GA)

1998-01-01

289

Prometheus Hot Leg Piping Concept  

SciTech Connect

The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

Gribik, Anastasia M. [Bechtel Bettis, Inc., Bettis Atomic Power Laboratory, West Mifflin, PA 15122 (United States); DiLorenzo, Peter A. [KAPL, Inc., Knolls Atomic Power Laboratory, Schenectady, NY 12301 (United States)

2007-01-30

290

Numerical heat-pipe modeling  

NASA Astrophysics Data System (ADS)

The research described in this paper was conducted to better understand numerical modeling of heat-pipe transients. In the numerical model, the vapor flow was assumed to be unsteady, compressible and one-dimensional, while the one-dimensional, unsteady, heat diffusion equation was used to model energy conduction through the heat-pipe wall. The liquid return process in the heat-pipe wick was not modeled. Finite difference techniques were used to solve the governing equations. Damping was needed to stabilize the numerical scheme. To validate the numerical model, experimental data was obtained from a copper-water heat-pipe start-up. The heat-pipe's external evaporator and condenser temperatures were recorded during the experiment. In the paper, the results from the numerical model are compared to the experimental data.

Bowman, Jerry; Sweeten, Richard W.

1989-06-01

291

Vibration analysis methods for piping  

NASA Astrophysics Data System (ADS)

Attention is given to flow vibrations in pipe flow induced by singularity points in the piping system. The types of pressure fluctuations induced by flow singularities are examined, including the intense wideband fluctuations immediately downstream of the singularity and the acoustic fluctuations encountered in the remainder of the circuit, and a theory of noise generation by unsteady flow in internal acoustics is developed. The response of the piping systems to the pressure fluctuations thus generated is considered, and the calculation of the modal characteristics of piping containing a dense fluid in order to obtain the system transfer function is discussed. The TEDEL program, which calculates the vibratory response of a structure composed of straight and curved pipes with variable mechanical characteristics forming a three-dimensional network by a finite element method, is then presented, and calculations of fluid-structural coupling in tubular networks are illustrated.

Gibert, R. J.

1981-09-01

292

Numerical-analytical investigation into impact pipe driving in soil with dry friction. Part I: Nondeformable external medium  

E-print Network

The study focuses on propagation of longitudinal waves in an elastic pipe partly embedded in a medium with dry friction. Mathematical formulation of the problem on the impact pipe driving into the soil is based on the model of longitudinal vibration of an elastic rod with taking into account lateral resistance. The lateral resistance of soil is described by the law of the contact dry friction. Numerical and analytical solutions to problems on longitudinal impulse loading of a pipe are compared.

Aleksandrova, Nadezhda

2013-01-01

293

Technology for concrete pipe manipulator  

NASA Astrophysics Data System (ADS)

The pipe manipulator is a developing mechatronic system to enhance productivity and protects workers from cave-ins in the trench while excavating and laying pipe. The pipe manipulator is for installing concrete pipe into the trench. It is an optical-electro-mechanical system. The mechanism is make up of two parts, the upside and underside. The upside is for lifting the equipment by backhoe and rotating the underside mechanism. It includes rigidity lift beams, holding pad, four-bar linkages, hydraulic cylinder, rotating support, and rotating mechanism. Holding pad will press the bucket back to keep the bucket hooking the pipe man safely and stably. The underside mechanism is for lifting, holding and adjusting the pipe section's stance. The underside mechanism includes support trolley, and lift fork. The support trolley is driven by hydraulic cylinder for moving the fork forward or backward while laying a pipe into trench. The fork is with a self-lock mechanism for preventing the pipe from slide out of the prongs. A new photoelectric locating system is developed for auto-measuring the installing pipe section's stance within the work area. The laser target has been developed as a key part in the photoelectric locating systems. The photoelectric target is a rotating polar coordinate. Photodiodes are used for making the polar radius. There is an angular displacement sensor sitting on the heart-axis of the target for measuring angle of the target rotating. The pipe manipulator can be located by the system, and the locating methods have been presented at last of the paper.

Li, Bin; Wang, Dan; Lin, Renzhi

2010-01-01

294

Technology for concrete pipe manipulator  

NASA Astrophysics Data System (ADS)

The pipe manipulator is a developing mechatronic system to enhance productivity and protects workers from cave-ins in the trench while excavating and laying pipe. The pipe manipulator is for installing concrete pipe into the trench. It is an optical-electro-mechanical system. The mechanism is make up of two parts, the upside and underside. The upside is for lifting the equipment by backhoe and rotating the underside mechanism. It includes rigidity lift beams, holding pad, four-bar linkages, hydraulic cylinder, rotating support, and rotating mechanism. Holding pad will press the bucket back to keep the bucket hooking the pipe man safely and stably. The underside mechanism is for lifting, holding and adjusting the pipe section's stance. The underside mechanism includes support trolley, and lift fork. The support trolley is driven by hydraulic cylinder for moving the fork forward or backward while laying a pipe into trench. The fork is with a self-lock mechanism for preventing the pipe from slide out of the prongs. A new photoelectric locating system is developed for auto-measuring the installing pipe section's stance within the work area. The laser target has been developed as a key part in the photoelectric locating systems. The photoelectric target is a rotating polar coordinate. Photodiodes are used for making the polar radius. There is an angular displacement sensor sitting on the heart-axis of the target for measuring angle of the target rotating. The pipe manipulator can be located by the system, and the locating methods have been presented at last of the paper.

Li, Bin; Wang, Dan; Lin, Renzhi

2009-12-01

295

WATER QUALITY AND TREATMENT CONSIDERATIONS FOR CEMENT-LINED AND A-C PIPE  

EPA Science Inventory

Both cement mortar lined (CML) and asbestos-cement pipes (A-C) are widely used in many water systems. Cement linings are also commonly applied in-situ after pipe cleaning, usually to prevent the recurrence of red water or tuberculation problems. Unfortunately, little consideratio...

296

Internal erosion during soil pipe flow: Role in gully erosion and hillslope instability  

Technology Transfer Automated Retrieval System (TEKTRAN)

Many field observations have lead to speculation on the role of piping in embankment failures, landslides, and gully erosion. However, there has not been a consensus on the subsurface flow and erosion processes involved and inconsistent use of terms have exasperated the problem. One such piping proc...

297

Forming Force Calculation and Experimental Study on HydroForming Process of Lined Steel Pipe  

Microsoft Academic Search

Corrosion of oil tubular goods is becoming more and more serious in the exploitation of oil and gas wells, so it is very significant to study new anti-corrosion materials of lined steel pipe. Aiming at the mechanical problem of lined steel pipe hydro-forming, a parametric finite element analysis (FEA) mechanical model is established in this paper to simulate the plastic

Zeng Dezhi; Lin Yuanhua; Zhu Dajiang; Yang Bin; Zhu Hongjun; Shi Taihe

2011-01-01

298

Evaluation of sea water piping system after fifteen years of service  

SciTech Connect

Seawater is the main cooling medium in the petrochemical plant. Failure of the seawater piping systems could lead to total shutdown of the plant. The main piping system in the plant consists of prestressed concrete cylinder pipe (PCCP), cement mortar--lined carbon steel, fiberglass and nickel-copper alloy N04400/ASTM B165 pipe. After more than fifteen years of experience with these materials, evaluation was made to select the most durable material for replacement projects and new construction. This paper discusses the problems associated with each material, repair procedure and materials selection decisions for the long-term operation of the plant.

Al Beed, A.A. [Saudi Petrochemical Co. (Saudi Arabia); Ali, M. [SABIC R and D (Saudi Arabia)

1999-11-01

299

A comparison of five benchmarks  

NASA Technical Reports Server (NTRS)

Five benchmark programs were obtained and run on the NASA Lewis CRAY X-MP/24. A comparison was made between the programs codes and between the methods for calculating performance figures. Several multitasking jobs were run to gain experience in how parallel performance is measured.

Huss, Janice E.; Pennline, James A.

1987-01-01

300

Simple mathematical law benchmarks human confrontations.  

PubMed

Many high-profile societal problems involve an individual or group repeatedly attacking another - from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a 'lone wolf'; identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds. PMID:24322528

Johnson, Neil F; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

2013-01-01

301

Simple mathematical law benchmarks human confrontations  

NASA Astrophysics Data System (ADS)

Many high-profile societal problems involve an individual or group repeatedly attacking another - from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a `lone wolf' identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds.

Johnson, Neil F.; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S.; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

2013-12-01

302

Simple mathematical law benchmarks human confrontations  

PubMed Central

Many high-profile societal problems involve an individual or group repeatedly attacking another – from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a ‘lone wolf'; identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds. PMID:24322528

Johnson, Neil F.; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S.; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

2013-01-01

303

Monitoring pipe line stress due to ground displacement  

SciTech Connect

Northwest Pipeline Corp. has a large-diameter natural gas pipe line system from Ignacio, Colo., to Sumas, Wash. At Douglas Pass in Colorado, large landslides required several sections of the line to be relocated outside the slide areas: 4,400 ft of new line in April 1962 and 3,200 ft in March 1963. No serious disruptions occurred for the next 16 years. Then in July 1979, some 1,200 ft had to be relocated. From 1980 to date, many landslides in the Douglas Pass area have caused new deformations, with the springs of 1983 and 1984 being the worst years. In 1980, Northwest Pipeline began engineering and geotechnical studies of the landslide problems. These led to instrumentation and pipe monitoring which indicated that pipe failure can be predicted and prevented if important slope deformations or increases in pipe stresses are detected early enough to implement some mitigating measures. Excavation of the pipe to relieve the stresses was used in most cases. The method was so successful that no pipe failure occurred in 1984 within instrumented sections, in spite of the exceptionally bad climatic conditions experienced.

Greenwood, J.H. Jr.

1986-04-01

304

Transient flows and pressure waves in pipes  

SciTech Connect

Transient laminar flows and pressure-wave propagations in pipes connected with components, commonly known as water hammer, are analyzed. The system studied consists of a constant-pressure vessel, a uniform circular pipe, a valve between them, and a receiver vessel. A pressure-wave equation and a linearized velocity equation are derived from the equations of mass and momentum conservation. Waveform distortion due to viscous dissipation and pipe-wall elastic expansion is characterized by a dimensionless transmission number, K. The coefficients of the damping of the pressure waves were found to be related to the roots of the Bessel function J{sub 0}. An exact solution of the pressure-wave equation was obtained numerically. The relationship between the distortion of a traveling wave and the transmission number K was studied. The problem is also calculated with a general-purpose computer code, COMMIX, which solves the exact mass conservation equation and Navier-Stokes equations. The COMMIX calculational results agreed well with the analytical solutions.

Wang, X.Q.; Sun, J.G.; Sha, W.T.

1994-06-01

305

Avoiding steam bubble collapse-induced water hammer in the auxiliary piping of steam power plants  

SciTech Connect

The mechanisms of steam bubble collapse-induced water hammer are identified for nominally horizontal or inclined pipes. On the basis of these observations, two methods of preventing steam bubble collapse-induced water hammer in nominally horizontal pipes are proposed. They are inclining them and injecting the water at a controlled rate at either the lowest point or injecting the water at several locations. The success of these methods is demonstrated for horizontal pipes and for pipes of other orientations. These ways of preventing steam bubble collapse-induced water hammer are then used to test filling strategies for L''-shaped pipes oriented in practically every way. Both methods are found to work though the application of multiple injection ports and has complications when applied to a complex piping system. The use of the recommended design guidelines for avoiding steam bubble collapse-induced water hammer is demonstrated in an example problem.

Lobo, C.A.O.C. (COPESP, Sao Paulo (Brazil)); Griffith, P. (Massachusetts Inst. of Tech., Cambridge, MA (United States))

1994-02-01

306

Inviscid vortex breakdown models in pipes  

NASA Astrophysics Data System (ADS)

The inviscid evolution along a pipe of two families of inlet cylindrical swirling flows is analysed using the Bragg-Hawthorne equation. The first flow corresponds to exact solutions of the axisymmetric Euler equations near the axis, at which the velocity field is singular. The quasi-cylindrical problem is reduced to solving a phase-plane first order differential equation. It is found that, for both converging and diverging pipes, cylindrical solutions for the downstream flow determined by the inlet flow exist even for very high values of the swirl parameter (L). The second family of inlet flows coincides with the first except inside an axial core of radius rc, where the flow now has constant axial velocity and rotates as a rigid body. For diverging or straight pipes, this regularised family exhibits the usual behaviour, with a maximum value of L = Lf above which one-cell cylindrical solutions for the downstream flow fail to exist, even for very small rc. The downstream flow may also stagnate at the axis above another value Lo < Lf. Thus, there is no inviscid breakdown unless the vortex core is (arbitrarily) regularised. Since regularization of singular inviscid flows is actually carried out by viscosity, it follows that, within the limitations of the present simple model, the presence of viscosity is essential to describe the phenomenon of vortex breakdown in pipes from the inviscid equations, regularising the usually singular inlet inviscid flow. The jet-like radial decay of the axial and swirl velocities in the present inlet model flows leads also to values of Lf closer to those observed experimentally than those found in some previous models.

Fernendez-Feria, R.; Ortega-Casanova, J.

307

Dhrystone: a synthetic systems programming benchmark  

Microsoft Academic Search

Reflecting current data on the use of programming language constructs in systems programming, a synthetic benchmark is constructed based on the distribution appearing in the data. The benchmark executes 100 Ada statements that are balanced in terms of the distribution of statement types, data types, and data locality. Pascal and C versions of the benchmark are discussed.

Reinhold P. Weicker

1984-01-01

308

The LINPACK Benchmark: past, present and future  

Microsoft Academic Search

This paper describes the LINPACK Benchmark (41) and some of its variations commonly used to assess perfor- mance of computer systems. Aside from the LINPACK benchmark suite, the TOP500 (43), and the HPL (48) code are presented. The latter is frequently used to obtained results for TOP500 submissions. Information is also given on how to interpret results of the benchmark

Jack J. Dongarra; Piotr Luszczek; Antoine Petitet

2003-01-01

309

DPF: A Data Parallel Fortran Benchmark Suite  

E-print Network

DPF: A Data Parallel Fortran Benchmark Suite Yu Charlie Hu S. Lennart Johnsson Dimitris Kehagias Parallel Processing Symposium, Geneva, Switzerland, April 1997. #12; DPF: A Data Parallel Fortran Benchmark@deas.harvard.edu Abstract We present the Data Parallel Fortran (DPF) benchmark suite, a set of data parallel Fortran codes

Johnsson, S. Lennart

310

Developing Internet E-Commerce Benchmarks  

Microsoft Academic Search

A benchmark is a standard for measuring and comparing the performance of like systems. For new product makers, a benchmark can provide important statistical information so products can be fine-tuned before their deployment. For end users, on the other hand, a benchmark can be used to compare the strengths and weaknesses of different products so that an informed decision can

Dawn N. Jutla; Peter Bodorik; Yie Wang

1999-01-01

311

NAS Parallel Benchmark Results 11-96. 1.0  

NASA Technical Reports Server (NTRS)

The NAS Parallel Benchmarks have been developed at NASA Ames Research Center to study the performance of parallel supercomputers. The eight benchmark problems are specified in a "pencil and paper" fashion. In other words, the complete details of the problem to be solved are given in a technical document, and except for a few restrictions, benchmarkers are free to select the language constructs and implementation techniques best suited for a particular system. These results represent the best results that have been reported to us by the vendors for the specific 3 systems listed. In this report, we present new NPB (Version 1.0) performance results for the following systems: DEC Alpha Server 8400 5/440, Fujitsu VPP Series (VX, VPP300, and VPP700), HP/Convex Exemplar SPP2000, IBM RS/6000 SP P2SC node (120 MHz), NEC SX-4/32, SGI/CRAY T3E, SGI Origin200, and SGI Origin2000. We also report High Performance Fortran (HPF) based NPB results for IBM SP2 Wide Nodes, HP/Convex Exemplar SPP2000, and SGI/CRAY T3D. These results have been submitted by Applied Parallel Research (APR) and Portland Group Inc. (PGI). We also present sustained performance per dollar for Class B LU, SP and BT benchmarks.

Bailey, David H.; Bailey, David; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

312

Superconducting pipes and levitating magnets.  

PubMed

Motivated by a beautiful demonstration of the Faraday and the Lenz laws in which a small neodymium magnet falls slowly through a conducting nonferromagnetic tube, we consider the dynamics of a magnet falling coaxially through a superconducting pipe. Unlike the case of normal conducting pipes, in which the magnet quickly reaches the terminal velocity, inside a superconducting tube the magnet falls freely. On the other hand, to enter the pipe the magnet must overcome a large electromagnetic energy barrier. For sufficiently strong magnets, the barrier is so large that the magnet will not be able to penetrate it and will be levitated over the mouth of the pipe. We calculate the work that must done to force the magnet to enter a superconducting tube. The calculations show that superconducting pipes are very efficient at screening magnetic fields. For example, the magnetic field of a dipole at the center of a short pipe of radius a and length L approximately > a decays, in the axial direction, with a characteristic length xi approximately 0.26a. The efficient screening of the magnetic field might be useful for shielding highly sensitive superconducting quantum interference devices. Finally, the motion of the magnet through a superconducting pipe is compared and contrasted to the flow of ions through a trans-membrane channel. PMID:17280160

Levin, Yan; Rizzato, Felipe B

2006-12-01

313

A numerical benchmark test for continuous casting of steel  

NASA Astrophysics Data System (ADS)

There is a continuously developing need for benchmarking of solidification simulations - from the theoretical as well as from the applied points of view. The benchmarking is usually done in two parts. The verification part confirms the proper numerical solution (Are we solving the equations correctly?) and the validation part (Are we solving the right equations?) confirms the proper response of the simulations regarding the experimental evidence. The history of related benchmarking shows differences of the results between different numerical methods, and differences in comparison with the experiments when solving even quite simple solidification situations. The present benchmark test proposes the verification benchmark for continuous casting of steel. Since the simulations of the temperatures, velocities, pressures and concentrations in the continuous casting represent a multiscale and multiphysics problem of high complexity (far away from a closed form solution), the verification can be done only by comparing the results of different numerical methods for solving the same governing equations. This has been done in the context of continuous casting by breaking the considered two dimensional problem into several sub problems by increasing complexity of geometry (straight in vertical direction, curved), boundary conditions (linear, non-linear), material properties (only Fe and Fe - C), microscopic considerations (Lever rule and Scheil rule). The governing equations complexity first involves only convective - diffusive heat transport with a predetermined velocity field, and assumed laminar and turbulent velocity calculations afterwards, modelled by a low Reynolds number turbulence model. Further complications involve the presence of the electromagnetic forces. The paper represents guidelines for the presentation of the numerical method, discretisation and results, as well as some of the results, obtained by the commercial finite volume based code and our in-house meshless method based laboratory code.

Šarler, B.; Vertnik, R.; Mramor, K.

2012-07-01

314

Piping instability resulting from bellows misalignment  

SciTech Connect

The failure of the single phase bellows and magnet test stand during quench testing of SSC dipole magnet DD0011 has led to much speculation about the inherent stability of operating SSC magnets. This note addresses the problem of instabilities resulting from both translational and angular misalignment between pipes connected by bellows in the general sense and with respect to the SSC single phase system specifically. Note that none of the instabilities referenced here result from bellows 'squirm'. Inelastic bellows failure is not within the scope of this work. The failure mode referenced here is an elastic instability. 3 refs., 7 figs.

Nicol, T.H.

1989-05-30

315

42 CFR 440.385 - Delivery of benchmark and benchmark-equivalent coverage through managed care entities.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Delivery of benchmark and benchmark-equivalent coverage through managed care entities...ASSISTANCE PROGRAMS SERVICES: GENERAL PROVISIONS Benchmark Benefit and Benchmark-Equivalent Coverage §...

2014-10-01

316

42 CFR 440.385 - Delivery of benchmark and benchmark-equivalent coverage through managed care entities.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Delivery of benchmark and benchmark-equivalent coverage through managed care entities...ASSISTANCE PROGRAMS SERVICES: GENERAL PROVISIONS Benchmark Benefit and Benchmark-Equivalent Coverage §...

2010-10-01

317

Abrasion protection in process piping  

SciTech Connect

Process piping often is subjected to failure from abrasion or a combination of abrasion and corrosion. Abrasion is a complex phenomenon, with many factors involved to varying degrees. Hard, mineral based alumina ceramic and basalt materials are used to provide protection against abrasion in many piping systems. Successful life extension examples are presented from many different industries. Lined piping components require special attention with regard to operating conditions as well as design and engineering considerations. Economic justification involves direct cost comparisons and avoided costs.

Accetta, J. [Abresist Corp., Urbana, IN (United States)

1996-07-01

318

Heat pipe transient response approximation.  

SciTech Connect

A simple and concise routine that approximates the response of an alkali metal heat pipe to changes in evaporator heat transfer rate is described. This analytically based routine is compared with data from a cylindrical heat pipe with a crescent-annular wick that undergoes gradual (quasi-steady) transitions through the viscous and condenser boundary heat transfer limits. The sonic heat transfer limit can also be incorporated into this routine for heat pipes with more closely coupled condensers. The advantages and obvious limitations of this approach are discussed. For reference, a source code listing for the approximation appears at the end of this paper.

Reid, R. S. (Robert Stowers)

2001-01-01

319

Variable conductance heat pipe technology  

NASA Technical Reports Server (NTRS)

Research and development programs in variable conductance heat pipe technology were conducted. The treatment has been comprehensive, involving theoretical and/or experimental studies in hydrostatics, hydrodynamics, heat transfer into and out of the pipe, fluid selection, and materials compatibility, in addition to the principal subject of variable conductance control techniques. Efforts were not limited to analytical work and laboratory experimentation, but extended to the development, fabrication and test of spacecraft hardware, culminating in the successful flight of the Ames Heat Pipe Experiment on the OAO-C spacecraft.

Marcus, B. D.; Edwards, D. K.; Anderson, W. T.

1973-01-01

320

Analysis of benchmark characteristics and benchmark performance prediction  

Microsoft Academic Search

Standard benchmarking provides to run-times for given programs on given machines, but fails to provide insight as to why those results were obtained (either in terms of machine or program characteristics) and fails to provide run-times for that program on some other machine, or some other programs on that machine. We have developed a machine-imdependent model of program execution to

Rafael H. Saavedra; Alan Jay Smith

1996-01-01

321

Heat pipe technology: A biblography with abstracts  

NASA Technical Reports Server (NTRS)

A bibliography of heat pipe research and development projects conducted during April through June 1972, is presented. The subjects discussed are: (1) general information, (2) heat pipe applications, (3) heat pipe theory, (4) design and fabrication, (5) test and operation, (6) subject and author index, and (7) heat pipe related patents.

1972-01-01

322

Determination of Secondary Encasement Pipe Design Pressure  

SciTech Connect

This document published results of iterative calculations for maximum tank farm transfer secondary pipe (encasement) pressure upon failure of the primary pipe. The maximum pressure was calculated from a primary pipe guillotine break. Results show encasement pipeline design or testing pressures can be significantly lower than primary pipe pressure criteria.

TEDESCHI, A.R.

2000-10-26

323

Grooving mill for pipe-heating department  

Microsoft Academic Search

To meet the rising demands on the strength and quality of seamless pipe, heat-treatment sections must be organized at pipe plants. To obtain the required geometric parameters of the pipe, a grooving mill for heat treatment of external pipe diameter over the whole length is established in the heating department. In accordance with the reequipment program at OAO Sinarskii Trubnyi

N. V. Pasechnik; N. A. Tselikov; A. I. Grinshpun; G. A. Furlender; A. V. Chekulaev

2007-01-01

324

Heat pipe technology: A bibliography with abstracts  

NASA Technical Reports Server (NTRS)

A cumulative bibliography on heat pipe research and development projects is presented. The subjects discussed are: (1) general information, (2) heat pipe applications, (3) heat pipe theory, (4) design and fabrication, (5) testing and operation, (6) subject and author index, and (7) heat pipe related patents.

1971-01-01

325

A homogeneous heat pipe design code  

NASA Technical Reports Server (NTRS)

A computer program was developed to facilitate parametric performance evaluation of heat pipes in lightweight heat rejection systems. A description of the code, user's manual, and sample inputs are provided. The emphasis is placed on the analysis and design of homogeneous wick heat pipes. The analysis of the annular heat pipe is included as part of the heat pipe radiator subroutine.

Nakashima, A. M.; Kikin, G. M.

1974-01-01

326

Acoustic Signal Processing for Pipe Condition Assessment  

EPA Science Inventory

Unique to prestressed concrete cylinder pipe (PCCP), individual wire breaks create an excitation in the pipe wall that may vary in response to the remaining compression of the pipe core. This project was designed to improve acoustic signal processing for pipe condition assessment...

327

Analysis of perforated-pipe watercollector systems  

Microsoft Academic Search

When there is the need for domestic or industrial use of water from a natural stream or lake, a filtering process through layers of soil and a perforated collector-pipe system is customarily used. The water enters the pipe through a series of small opening cut in the pipe wall. Discharge through the pipe increasing as flow proceeds along its length.

Rouhollah Fatahi; Otto Haszpra

2004-01-01

328

Heat pipe experiment on SPAS 01  

NASA Astrophysics Data System (ADS)

The second flight of Challenger carried a heat pipe experiment, designed to measure the performance of constant conductance heat pipe diodes over a period of 16 hr. The experiment platform and the flight results on variable conductance heat pipe housekeeping radiators, including the temperature distribution at these heat pipe versus experiment time are presented. All equipment is shown to be space qualified.

Kock, H.; Kreeb, H.; Savage, C.

1986-08-01

329

Ground truth and benchmarks for performance evaluation  

NASA Astrophysics Data System (ADS)

Progress in algorithm development and transfer of results to practical applications such as military robotics requires the setup of standard tasks, of standard qualitative and quantitative measurements for performance evaluation and validation. Although the evaluation and validation of algorithms have been discussed for over a decade, the research community still faces a lack of well-defined and standardized methodology. The range of fundamental problems include a lack of quantifiable measures of performance, a lack of data from state-of-the-art sensors in calibrated real-world environments, and a lack of facilities for conducting realistic experiments. In this research, we propose three methods for creating ground truth databases and benchmarks using multiple sensors. The databases and benchmarks will provide researchers with high quality data from suites of sensors operating in complex environments representing real problems of great relevance to the development of autonomous driving systems. At NIST, we have prototyped a High Mobility Multi-purpose Wheeled Vehicle (HMMWV) system with a suite of sensors including a Riegl ladar, GDRS ladar, stereo CCD, several color cameras, Global Position System (GPS), Inertial Navigation System (INS), pan/tilt encoders, and odometry . All sensors are calibrated with respect to each other in space and time. This allows a database of features and terrain elevation to be built. Ground truth for each sensor can then be extracted from the database. The main goal of this research is to provide ground truth databases for researchers and engineers to evaluate algorithms for effectiveness, efficiency, reliability, and robustness, thus advancing the development of algorithms.

Takeuchi, Ayako; Shneier, Michael; Hong, Tsai Hong; Chang, Tommy; Scrapper, Christopher; Cheok, Geraldine S.

2003-09-01

330

Flexible heat pipe cold plates for aircraft thermal control  

Microsoft Academic Search

This paper describes the development of flexible heat pipe cold plate (FHPCP) technology for aircraft thermal control. Four different FHPCP's were constructed for a variety of difficult aircraft cooling problems. This included an electronics package embedded in a moving actuator, and a new digital computer installed in a fighter aircraft upgrade. In each application, a cold plate transfers the electronics'

Nelson Gernert; David Sarraf; Marc Steinberg

1991-01-01

331

Geothermal Heat Pump Benchmarking Report  

SciTech Connect

A benchmarking study was conducted on behalf of the Department of Energy to determine the critical factors in successful utility geothermal heat pump programs. A Successful program is one that has achieved significant market penetration. Successfully marketing geothermal heat pumps has presented some major challenges to the utility industry. However, select utilities have developed programs that generate significant GHP sales. This benchmarking study concludes that there are three factors critical to the success of utility GHP marking programs: (1) Top management marketing commitment; (2) An understanding of the fundamentals of marketing and business development; and (3) An aggressive competitive posture. To generate significant GHP sales, competitive market forces must by used. However, because utilities have functioned only in a regulated arena, these companies and their leaders are unschooled in competitive business practices. Therefore, a lack of experience coupled with an intrinsically non-competitive culture yields an industry environment that impedes the generation of significant GHP sales in many, but not all, utilities.

None

1997-01-17

332

Physics of heat pipe rewetting  

NASA Technical Reports Server (NTRS)

This is the final report which summarizes the research accomplishments under the project entitled 'Physics of Heat Pipe Rewetting' under NASA Grant No. NAG 9-525, Basic, during the period of April 1, 1991 to January 31, 1994. The objective of the research project was to investigate both analytically and experimentally the rewetting characteristics of the heated, grooved plate. The grooved plate is to simulate the inner surface of the vapor channel in monogroove heat pipes for space station design. In such designs, the inner surface of the vapor channel is threaded with monogrooves. When the heat pipe is thermally overloaded, dryout of the monogroove surface occurs. Such a dryout surface should be promptly rewetted to prevent the failure of the heat pipe operation in the thermal radiator of the space station.

Chan, S. H.

1994-01-01

333

Heat Pipes: An Industrial Application  

E-print Network

This paper reviews the basics of heat pipe exchangers. Included are how they are constructed, how they operate, where they have application, and various aspects of evaluating a potential application. After discussing the technical aspects of heat...

Murray, F.

1984-01-01

334

Corrugated pipe adhesive applicator apparatus  

DOEpatents

Apparatus for coating selected portions of the troughs of a corrugated pipe with an adhesive includes a support disposed within the pipe with a reservoir containing the adhesive disposed on the support. A pump, including a spout, is utilized for supplying the adhesive from the reservoir to a trough of the pipe. A rotatable applicator is supported on the support and contacts the trough of the pipe. The applicator itself is sized so as to fit within the trough, and contacts the adhesive in the trough and spreads the adhesive in the trough upon rotation. A trough shield, supported by the support and disposed in the path of rotation of the applicator, is utilized to prevent the applicator from contacting selected portions of the trough. A locator head is also disposed on the support and provides a way for aligning the spout, the applicator, and the trough shield with the trough. 4 figs.

Shirey, R.A.

1983-06-14

335

Heat pipe radiators for space  

NASA Technical Reports Server (NTRS)

Analysis of the data heat pipe radiator systems tested in both vacuum and ambient environments was continued. The systems included (1) a feasibility VCHP header heat-pipe panel, (2) the same panel reworked to eliminate the VCHP feature and referred to as the feasibility fluid header panel, and (3) an optimized flight-weight fluid header panel termed the 'prototype.' A description of freeze-thaw thermal vacuum tests conducted on the feasibility VCHP was included. In addition, the results of ambient tests made on the feasibility fluid header are presented, including a comparison with analytical results. A thermal model of a fluid header heat pipe radiator was constructed and a computer program written. The program was used to make a comparison of the VCHP and fluid-header concepts for both single and multiple panel applications. The computer program was also employed for a parametric study, including optimum feeder heat pipe spacing, of the prototype fluid header.

Sellers, J. P.

1976-01-01

336

Outlook for Industrial Energy Benchmarking  

E-print Network

Maintenance Operating Expenses (including energy costs) ? Distribution ? Sales & Marketing Some companies, such as DuPont, Royal Dutch ShelL Dow, Lyondell, and Exxon, have dedicated energy management teams which collect information and do internal... BENCHMARKING In 1989, DuPont set out to answer two questions about power and energy: ? How does DuPont compare to leading companies in technology, cost, performance and management of the Power and Utilities function? ? What actions should DuPont take...

Hartley, Z.

337

Intermediate Temperature Water Heat Pipe Tests  

NASA Technical Reports Server (NTRS)

Heat pipes are among the most promising technologies for space radiator systems. Water heat pipes are explored in the intermediate temperature range of 400 to above 500 K. The thermodynamic and thermo-physical properties of water are reviewed in this temperature range. Test data are reported for a copper-water heat pipe. The heat pipe was tested under different orientations. Water heat pipes show promise in this temperature range. Fabrication and testing issues are being addressed.

Devarakonda, Angirasa; Xiong, Da-Xi; Beach, Duane E.

2005-01-01

338

Lifetests of telecommunications satellite heat pipes  

Microsoft Academic Search

The life testing of low temperature heat pipes designed for satellite thermal control is discussed. Five stainless steel\\/ammonia artery heat pipes and four aluminum\\/ammonia artery heat pipes were operated at elevated temperatures of about 60 C with a heat load of 15 watts for each pipe. In addition, two axially grooved aluminum\\/ammonia heat pipes operating at 60 C with a

W. D. Muenzel

1979-01-01

339

Unsteady axial viscoelastic pipe flows  

Microsoft Academic Search

The main objective of this work is to examine in detail basic unsteady pipe flows and to investigate any new physical phenomena. We take the viscoelastic upper-convected Maxwell fluid as our non-Newtonian model and consider the flow of such a fluid in pipes of uniform circular cross-section in the following three cases: 1.(a) when the pressure gradient varies exponentially with

K. D. Rahaman; H. Ramkissoon

1995-01-01

340

Heat pipe turbine vane cooling  

SciTech Connect

The applicability of using heat pipe principles to cool gas turbine vanes is addressed in this beginning program. This innovative concept involves fitting out the vane interior as a heat pipe and extending the vane into an adjacent heat sink, thus transferring the vane incident heat transfer through the heat pipe to heat sink. This design provides an extremely high heat transfer rate and a uniform temperature along the vane due to the internal change of phase of the heat pipe working fluid. Furthermore, this technology can also eliminate hot spots at the vane leading and trailing edges and increase the vane life by preventing thermal fatigue cracking. There is also the possibility of requiring no bleed air from the compressor, and therefore eliminating engine performance losses resulting from the diversion of compressor discharge air. Significant improvement in gas turbine performance can be achieved by using heat pipe technology in place of conventional air cooled vanes. A detailed numerical analysis of a heat pipe vane will be made and an experimental model will be designed in the first year of this new program.

Langston, L.; Faghri, A. [Connecticut Univ., Storrs, CT (United States). Dept. of Mechanical Engineering

1995-12-31

341

Heat pipe cooled power magnetics  

NASA Technical Reports Server (NTRS)

A high frequency, high power, low specific weight (0.57 kg/kW) transformer developed for space use was redesigned with heat pipe cooling allowing both a reduction in weight and a lower internal temperature rise. The specific weight of the heat pipe cooled transformer was reduced to 0.4 kg/kW and the highest winding temperature rise was reduced from 40 C to 20 C in spite of 10 watts additional loss. The design loss/weight tradeoff was 18 W/kg. Additionally, allowing the same 40 C winding temperature rise as in the original design, the KVA rating is increased to 4.2 KVA, demonstrating a specific weight of 0.28 kg/kW with the internal loss increased by 50W. This space environment tested heat pipe cooled design performed as well electrically as the original conventional design, thus demonstrating the advantages of heat pipes integrated into a high power, high voltage magnetic. Another heat pipe cooled magnetic, a 3.7 kW, 20A input filter inductor was designed, developed, built, tested, and described. The heat pipe cooled magnetics are designed to be Earth operated in any orientation.

Chester, M. S.

1979-01-01

342

Benchmarking the Q/TRAN thermal analysis computer code  

SciTech Connect

Q/TRAN, a new thermal analysis computer code, was examined for its use in modeling the responses of radioactive material shipping casks in accident conditions. A comparison between Q/TRAN and HEATING-6 was made using four benchmark problems chosen for their cask-like geometries and similarity to packaging thermal environments. HEATING-6 was chosen for comparison because HEATING-5, a predecessor to HEATING-6, was used in previous cask analyses. Modeling capabilities for each code are discussed as they relate to the four benchmark model problems. Q/TRAN was determined to be advantageous because of (1) its superior numerical algorithms and (2) the pre- and postprocessing capabilities (with PATRAN) that allow the graphic display of flexible meshing schemes and thermal results.

Manteufel, R.D.; Klein, D.E.; Yoshimura, H.R.

1986-01-01

343

Piping inspection round robin  

SciTech Connect

The piping inspection round robin was conducted in 1981 at the Pacific Northwest National Laboratory (PNNL) to quantify the capability of ultrasonics for inservice inspection and to address some aspects of reliability for this type of nondestructive evaluation (NDE). The round robin measured the crack detection capabilities of seven field inspection teams who employed procedures that met or exceeded the 1977 edition through the 1978 addenda of the American Society of Mechanical Engineers (ASME) Section 11 Code requirements. Three different types of materials were employed in the study (cast stainless steel, clad ferritic, and wrought stainless steel), and two different types of flaws were implanted into the specimens (intergranular stress corrosion cracks (IGSCCs) and thermal fatigue cracks (TFCs)). When considering near-side inspection, far-side inspection, and false call rate, the overall performance was found to be best in clad ferritic, less effective in wrought stainless steel and the worst in cast stainless steel. Depth sizing performance showed little correlation with the true crack depths.

Heasler, P.G.; Doctor, S.R. [Pacific Northwest National Lab., Richland, WA (United States)

1996-04-01

344

Meteoroid Protection Methods for Spacecraft Radiators Using Heat Pipes  

NASA Technical Reports Server (NTRS)

Various aspects of achieving a low mass heat pipe radiator for the nuclear electric propulsion spacecraft were studied. Specific emphasis was placed on a concept applicable to a closed Brayton cycle power sub-system. Three aspects of inter-related problems were examined: (1) the armor for meteoroid protection, (2) emissivity of the radiator surface, and (3) the heat pipe itself. The study revealed several alternatives for the achievement of the stated goal, but a final recommendation for the best design requires further investigation.

Ernst, D. M.

1979-01-01

345

New Implementations and Results for the NAS Parallel Benchmarks 2  

Microsoft Academic Search

We present new implementations and results for the NAS Parallel Benchmarks 2suite. The suite currently consists of seven programs. Of these LU, SP, BT, MG andFT have previously been released. Here we describe implementations of EP and IS, aswell as a rewritten version of FT that corrects some problems with the original release.Performance results are shown for several architectures: IBM

William Saphir; Rob F. Van Der Wijngaart; Alex Woo; Maurice Yarrow

1997-01-01

346

Transient conjugated heat transfer in pipes involving two-dimensional wall and axial fluid conduction  

Microsoft Academic Search

This paper presents an analysis for an unsteady conjugated heat transfer problem in thermally developing laminar pipe flow, involving two-dimensional wall and fluid axial conduction. The problem is solved numerically by a finite-difference method for a thick-walled, infinitely long, two-regional pipe which is initially isothermal with a step change in the constant outside temperature of the heated downstream section. A

?efik Bilir

2002-01-01

347

Present Status and Extensions of the Monte Carlo Performance Benchmark  

NASA Astrophysics Data System (ADS)

The NEA Monte Carlo Performance benchmark started in 2011 aiming to monitor over the years the abilities to perform a full-size Monte Carlo reactor core calculation with a detailed power production for each fuel pin with axial distribution. This paper gives an overview of the contributed results thus far. It shows that reaching a statistical accuracy of 1 % for most of the small fuel zones requires about 100 billion neutron histories. The efficiency of parallel execution of Monte Carlo codes on a large number of processor cores shows clear limitations for computer clusters with common type computer nodes. However, using true supercomputers the speedup of parallel calculations is increasing up to large numbers of processor cores. More experience is needed from calculations on true supercomputers using large numbers of processors in order to predict if the requested calculations can be done in a short time. As the specifications of the reactor geometry for this benchmark test are well suited for further investigations of full-core Monte Carlo calculations and a need is felt for testing other issues than its computational performance, proposals are presented for extending the benchmark to a suite of benchmark problems for evaluating fission source convergence for a system with a high dominance ratio, for coupling with thermal-hydraulics calculations to evaluate the use of different temperatures and coolant densities and to study the correctness and effectiveness of burnup calculations. Moreover, other contemporary proposals for a full-core calculation with realistic geometry and material composition will be discussed.

Hoogenboom, J. Eduard; Petrovic, Bojan; Martin, William R.

2014-06-01

348

Material characterizations for Benchmark 1 and Benchmark 2  

NASA Astrophysics Data System (ADS)

This report summarizes material testing on three metals used in the Numisheet 2014 Benchmark Study, a DP 600 steel sheet, a TRIP 780 steel sheet, and an aluminum alloy 5182-O sheet. The tests include r value, yield stress, and hardening in uniaxial tension at 15 degree increments of the loading axis in the plane of the sheet, r value, yield stress, and hardening in equal biaxial tension, and forming limit curves for all three metals. In addition, cyclic tension-compression tests along the rolling direction are reported for the DP 600 and aluminum alloy.

Stoughton, Thomas B.; Shi, Ming F.; Huang, Gang; Yoon, Jeong Whan

2013-12-01

349

Effects of pipe diameters on the pressures during delayed load rejection in high-head pumped storage power stations  

NASA Astrophysics Data System (ADS)

High-head pumped storage power stations face serious problems related to the transient process, especially in the area of delayed load rejection in stations with annular piping layouts. The controlled pressures are adversely affected, which leads to many problems in the engineering design phase. In this study, we investigated this condition through theoretical analysis, numerical simulation, and actual engineering practice. We concluded that the root cause of the pressure issues is the flow switching resulted from the non-synchronous changes in pressure between each branch pipe. Moreover, we examined the impact of the diameters of the upstream main pipe and branch pipe on the controlled pressures and determined that the diameter of the branch pipe has a major influence on the pressures as it changes the flow switching rate. A similar investigation was conducted for downstream pipes. Our conclusions can be applied to actual engineering practice for high-head pumped storage power stations.

Zeng, W.; Yang, J. D.

2014-12-01

350

A pipe stress program for the microcomputer: III  

SciTech Connect

A program for multianchor stress problems in piping is presented. This paper focuses on introducing and verifying data, running the program, and analyzing the results. The portion of pipe is selected, and an isometric sketch made of it. Branch divisions are specified. An ''origin point'' must be chosen so that every member can be dimensioned from the chosen origin in every direction. The origin should be in the center, and at floor level. The pipe variables are then calculated. A loading diagram is derived. Various moments--gravity moments, bending moments--are calculated to determine distribution of load. A molar circle type analysis must be made only for higher stresses. This program publishes a generalized scope code stress.

Bridge, T.E.

1983-04-01

351

NEP heat pipe radiators. [Nuclear Electric Propulsion  

NASA Technical Reports Server (NTRS)

This paper covers improvements of heat pipe radiators for the thermionic NEP design. Liquid metal heat pipes are suitable as spacecraft radiator elements because of high thermal conductance, low mass and reliability, but the NEP thermionic system design was too large and difficult to fabricate. The current integral collector-radiator design consisting of several layers of thermionic converters, the annular-tangential collector heat pipe, the radiator heat pipe, and the transition zone designed to minimize the temperature difference between the collector heat pipe and radiator heat pipe are described. Finally, the design of micrometeoroid armor protection and the fabrication of the stainless steel annular heat pipe with a tangential arm are discussed, and it is concluded that the heat rejection system for the thermionic NEP system is well advanced, but the collector-radiator heat pipe transition and the 8 to 10 m radiator heat pipe with two bends require evaluation.

Ernst, D. M.

1979-01-01

352

Estimate CO 2 storage capacity of the Johansen formation: numerical investigations beyond the benchmarking exercise  

Microsoft Academic Search

In this paper, Shell’s in-house reservoir simulator MoReS is applied to a recently introduced CO2 sequestration benchmark problem entitled “Estimation of the CO2 Storage Capacity of a Geological Formation” (Class et al. 2008). The principal objective of this benchmark is the simulation of CO2 distribution within a modeling region, and leakage of CO2 outside of it, for a period of

Lingli Wei; Fredrik Saaf

2009-01-01

353

The reflection of guided waves from simple dents in pipes.  

PubMed

Guided elastic waves have been anticipated as a rapid screening technique for pipe inspection. Dents occurring in pipes are a severe problem which may lead to the possibility of pipe failure. A study of the reflection characteristics of guided waves from dents of varying geometrical profile in pipes is investigated through experiments. Dented region is represented by a series of circumferential cross-sections and its geometric parameters are described by axial length and the maximum and minimum outer diameters. Both single and double sided dents are mechanically simulated in hollow aluminum pipes and then experimentally tested by exciting the longitudinal L(0,2) mode. A quantitative parameter, so-called deformation rate relating to the maximum and minimum outer diameters of the dents is defined to evaluate the effect of the extent of the deformation on the reflection. For both types of dents, it is shown that the reflection coefficients of the L(0,2) mode are all approximately a linear function of their respective deformation rates. Mode conversion occurs at the dents and reflections of the F(1,3) mode are identified. The results show that the amplitude of the reflected F(1,3) mode is generally higher when the dent has stronger non-axisymmetric features. PMID:25497001

Ma, Shuyi; Wu, Zhanjun; Wang, Yishou; Liu, Kehai

2015-03-01

354

A solar mean field dynamo benchmark  

NASA Astrophysics Data System (ADS)

Context: The solar magnetic activity and cycle are linked to an internal dynamo. Numerical simulations are an efficient and accurate tool to investigate such intricate dynamical processes. Aims: We present the results of an international numerical benchmark study based on two-dimensional axisymmetric mean field solar dynamo models in spherical geometry. The purpose of this work is to provide reference cases that can be analyzed in detail and that can help in further development and validation of numerical codes that solve such kinematic problems. Methods: The results of eight numerical codes solving the induction equation in the framework of mean field theory are compared for three increasingly computationally intensive models of the solar dynamo: an ?? dynamo with constant magnetic diffusivity, an ?? dynamo with magnetic diffusivity sharply varying with depth and an example of a flux-transport Babcock-Leighton dynamo which includes a non-local source term and one large single cell of meridional circulation per hemisphere. All cases include a realistic profile of differential rotation and thus a sharp tachocline. Results: The most important finding of this study is that all codes agree quantitatively to within less than a percent for the ?? dynamo cases and within a few percent for the flux-transport case. Both the critical dynamo numbers for the onset of dynamo action and the corresponding cycle periods are reasonably well recovered by all codes. Detailed comparisons of butterfly diagrams and specific cuts of both toroidal and poloidal fields at given latitude and radius confirm the good quantitative agreement. Conclusions: We believe that such a benchmark study will be a very useful tool since it provides detailed standard cases for comparison and reference.

Jouve, L.; Brun, A. S.; Arlt, R.; Brandenburg, A.; Dikpati, M.; Bonanno, A.; Käpylä, P. J.; Moss, D.; Rempel, M.; Gilman, P.; Korpi, M. J.; Kosovichev, A. G.

2008-06-01

355

Gaia FGK benchmark stars: Metallicity  

NASA Astrophysics Data System (ADS)

Context. To calibrate automatic pipelines that determine atmospheric parameters of stars, one needs a sample of stars, or "benchmark stars", with well-defined parameters to be used as a reference. Aims: We provide detailed documentation of the iron abundance determination of the 34 FGK-type benchmark stars that are selected to be the pillars for calibration of the one billion Gaia stars. They cover a wide range of temperatures, surface gravities, and metallicities. Methods: Up to seven different methods were used to analyze an observed spectral library of high resolutions and high signal-to-noise ratios. The metallicity was determined by assuming a value of effective temperature and surface gravity obtained from fundamental relations; that is, these parameters were known a priori and independently from the spectra. Results: We present a set of metallicity values obtained in a homogeneous way for our sample of benchmark stars. In addition to this value, we provide detailed documentation of the associated uncertainties. Finally, we report a value of the metallicity of the cool giant ? Phe for the first time. Based on NARVAL and HARPS data obtained within the Gaia DPAC (Data Processing and Analysis Consortium) and coordinated by the GBOG (Ground-Based Observations for Gaia) working group and on data retrieved from the ESO-ADP database.Tables 6-76 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/564/A133

Jofré, P.; Heiter, U.; Soubiran, C.; Blanco-Cuaresma, S.; Worley, C. C.; Pancino, E.; Cantat-Gaudin, T.; Magrini, L.; Bergemann, M.; González Hernández, J. I.; Hill, V.; Lardo, C.; de Laverny, P.; Lind, K.; Masseron, T.; Montes, D.; Mucciarelli, A.; Nordlander, T.; Recio Blanco, A.; Sobeck, J.; Sordo, R.; Sousa, S. G.; Tabernero, H.; Vallenari, A.; Van Eck, S.

2014-04-01

356

Magnetic refrigeration apparatus with heat pipes  

DOEpatents

A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe of pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

Barclay, John A. (Los Alamos, NM); Prenger, Jr., F. Coyne (Madison, WI)

1987-01-01

357

Benchmarking for Excellence and the Nursing Process  

NASA Technical Reports Server (NTRS)

Nursing is a service profession. The services provided are essential to life and welfare. Therefore, setting the benchmark for high quality care is fundamental. Exploring the definition of a benchmark value will help to determine a best practice approach. A benchmark is the descriptive statement of a desired level of performance against which quality can be judged. It must be sufficiently well understood by managers and personnel in order that it may serve as a standard against which to measure value.

Sleboda, Claire

1999-01-01

358

Pipe crawler with extendable legs  

DOEpatents

A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs.

Zollinger, W.T.

1992-06-16

359

Flexible ultrasonic pipe inspection apparatus  

DOEpatents

A flexible, modular ultrasonic pipe inspection apparatus, comprises a flexible, hollow shaft that carries a plurality of modules, including at least one rotatable ultrasonic transducer, a motor/gear unit, and a position/signal encoder. The modules are connected by flexible knuckle joints that allow each module of the apparatus to change its relative orientation with respect to a neighboring module, while the shaft protects electrical wiring from kinking or buckling while the apparatus moves around a tight corner. The apparatus is moved through a pipe by any suitable means, including a tether or drawstring attached to the nose or tail, differential hydraulic pressure, or a pipe pig. The rotational speed of the ultrasonic transducer and the forward velocity of the apparatus are coordinated so that the beam sweeps out the entire interior surface of the pipe, enabling the operator to accurately assess the condition of the pipe wall and determine whether or not leak-prone corrosion damage is present. 7 figs.

Jenkins, C.F.; Howard, B.D.

1998-06-23

360

NASA Software Engineering Benchmarking Effort  

NASA Technical Reports Server (NTRS)

Benchmarking was very interesting and provided a wealth of information (1) We did see potential solutions to some of our "top 10" issues (2) We have an assessment of where NASA stands with relation to other aerospace/defense groups We formed new contacts and potential collaborations (1) Several organizations sent us examples of their templates, processes (2) Many of the organizations were interested in future collaboration: sharing of training, metrics, Capability Maturity Model Integration (CMMI) appraisers, instructors, etc. We received feedback from some of our contractors/ partners (1) Desires to participate in our training; provide feedback on procedures (2) Welcomed opportunity to provide feedback on working with NASA

Godfrey, Sally; Rarick, Heather

2012-01-01

361

Benchmarks for acute stroke care delivery  

PubMed Central

Objective Despite widespread interest in many jurisdictions in monitoring and improving the quality of stroke care delivery, benchmarks for most stroke performance indicators have not been established. The objective of this study was to develop data-derived benchmarks for acute stroke quality indicators. Design Nine key acute stroke quality indicators were selected from the Canadian Stroke Best Practice Performance Measures Manual. Participants A population-based retrospective sample of patients discharged from 142 hospitals in Ontario, Canada, between 1 April 2008 and 31 March 2009 (N = 3191) was used to calculate hospital rates of performance and benchmarks. Intervention The Achievable Benchmark of Care (ABC™) methodology was used to create benchmarks based on the performance of the upper 15% of patients in the top-performing hospitals. Main Outcome Measures Benchmarks were calculated for rates of neuroimaging, carotid imaging, stroke unit admission, dysphasia screening and administration of stroke-related medications. Results The following benchmarks were derived: neuroimaging within 24 h, 98%; admission to a stroke unit, 77%; thrombolysis among patients arriving within 2.5 h, 59%; carotid imaging, 93%; dysphagia screening, 88%; antithrombotic therapy, 98%; anticoagulation for atrial fibrillation, 94%; antihypertensive therapy, 92% and lipid-lowering therapy, 77%. ABC™ acute stroke care benchmarks achieve or exceed the consensus-based targets required by Accreditation Canada, with the exception of dysphagia screening. Conclusions Benchmarks for nine hospital-based acute stroke care quality indicators have been established. These can be used in the development of standards for quality improvement initiatives. PMID:24141011

Hall, Ruth E.; Khan, Ferhana; Bayley, Mark T.; Asllani, Eriola; Lindsay, Patrice; Hill, Michael D.; O'Callaghan, Christina; Silver, Frank L.; Kapral, Moira K.

2013-01-01

362

Method and system for benchmarking computers  

DOEpatents

A testing system and method for benchmarking computer systems. The system includes a store containing a scalable set of tasks to be performed to produce a solution in ever-increasing degrees of resolution as a larger number of the tasks are performed. A timing and control module allots to each computer a fixed benchmarking interval in which to perform the stored tasks. Means are provided for determining, after completion of the benchmarking interval, the degree of progress through the scalable set of tasks and for producing a benchmarking rating relating to the degree of progress for each computer.

Gustafson, John L. (Ames, IA)

1993-09-14

363

Heat pipe - Design and fabrication for a magnetron and TWT of radar systems  

NASA Astrophysics Data System (ADS)

The present investigation is concerned with an employment of heat pipes instead of local ventilator systems in two cases, including a magnetron and a traveling-wave tube (TWT). In the case of the magnetron utilizing a ventilation system, it was found that much noise was produced by the general ventilation system, the magnetron centrifugal fan, and the air motion in the magnetron. In order to solve the noise problem, the installation of heat pipes was considered. Details related to the design and the appropriate installation of the heat pipe are discussed. The second application of a heat pipe is related to the design of a cold plate for draining the heat generated by the operation of a 1200 W TWT in a naval cabinet. The achievement of a low noise level and a low TWT collector temperature were the objectives which led to the consideration of an employment of heat pipes in this case.

Alesse, R.; Corsi, U.; Malagoli, G.

1983-10-01

364

[Study on the automatic parameters identification of water pipe network model].  

PubMed

Based on the problems analysis on development and application of water pipe network model, the model parameters automatic identification is regarded as a kernel bottleneck of model's application in water supply enterprise. The methodology of water pipe network model parameters automatic identification based on GIS and SCADA database is proposed. Then the kernel algorithm of model parameters automatic identification is studied, RSA (Regionalized Sensitivity Analysis) is used for automatic recognition of sensitive parameters, and MCS (Monte-Carlo Sampling) is used for automatic identification of parameters, the detail technical route based on RSA and MCS is presented. The module of water pipe network model parameters automatic identification is developed. At last, selected a typical water pipe network as a case, the case study on water pipe network model parameters automatic identification is conducted and the satisfied results are achieved. PMID:20329520

Jia, Hai-Feng; Zhao, Qi-Feng

2010-01-01

365

Pynamic: the Python Dynamic Benchmark  

SciTech Connect

Python is widely used in scientific computing to facilitate application development and to support features such as computational steering. Making full use of some of Python's popular features, which improve programmer productivity, leads to applications that access extremely high numbers of dynamically linked libraries (DLLs). As a result, some important Python-based applications severely stress a system's dynamic linking and loading capabilities and also cause significant difficulties for most development environment tools, such as debuggers. Furthermore, using the Python paradigm for large scale MPI-based applications can create significant file IO and further stress tools and operating systems. In this paper, we present Pynamic, the first benchmark program to support configurable emulation of a wide-range of the DLL usage of Python-based applications for large scale systems. Pynamic has already accurately reproduced system software and tool issues encountered by important large Python-based scientific applications on our supercomputers. Pynamic provided insight for our system software and tool vendors, and our application developers, into the impact of several design decisions. As we describe the Pynamic benchmark, we will highlight some of the issues discovered in our large scale system software and tools using Pynamic.

Lee, G L; Ahn, D H; de Supinksi, B R; Gyllenhaal, J C; Miller, P J

2007-07-10

366

Mutual Fund Performance Evaluation: A Comparison of Benchmarks and Benchmark Comparisons  

Microsoft Academic Search

Our primary goal in this paper is to ascertain whether the absolute and relative rankings of managed funds are sensitive to the benchmark chosen to measure normal performance. We employ the standard CAPM benchmarks and a variety of APT benchmarks to investigate this question. We found that there is little similarity between the absolute and relative mutual fund rankings obtained

Bruce N. Lehmann; David M. Modest

1987-01-01

367

46 CFR 56.30-3 - Piping joints (reproduces 110).  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56...APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping...

2012-10-01

368

46 CFR 56.30-3 - Piping joints (reproduces 110).  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56...APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping...

2013-10-01

369

46 CFR 56.30-3 - Piping joints (reproduces 110).  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56...APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping...

2011-10-01

370

46 CFR 56.30-3 - Piping joints (reproduces 110).  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56...APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping...

2010-10-01

371

46 CFR 154.512 - Piping: Thermal isolation.  

Code of Federal Regulations, 2010 CFR

...Shipping 5 2010-10-01 2010-10-01 false Piping: Thermal isolation. 154.512 Section 154.512 Shipping ...Cargo and Process Piping Systems § 154.512 Piping: Thermal isolation. Low temperature piping must be thermally...

2010-10-01

372

24 CFR 3280.705 - Gas piping systems.  

Code of Federal Regulations, 2013 CFR

...B36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded brass pipe in iron...may be used. Threaded brass pipe shall comply with ASTM B43-91, Standard Specification for Seamless Red Brass Pipe, Standard Sizes....

2013-04-01

373

24 CFR 3280.705 - Gas piping systems.  

Code of Federal Regulations, 2014 CFR

...B36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded brass pipe in iron...may be used. Threaded brass pipe shall comply with ASTM B43-91, Standard Specification for Seamless Red Brass Pipe, Standard Sizes....

2014-04-01

374

24 CFR 3280.706 - Oil piping systems.  

Code of Federal Regulations, 2010 CFR

...Steel or wrought-iron pipe shall comply with ANSI B 36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded copper or brass pipe in iron pipe sizes may be used. ...Standard Specification for Seamless Copper Water Tube,...

2010-04-01

375

24 CFR 3280.706 - Oil piping systems.  

Code of Federal Regulations, 2014 CFR

...Steel or wrought-iron pipe shall comply with ANSI B 36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded copper or brass pipe in iron pipe sizes may be used. ...Standard Specification for Seamless Copper Water Tube,...

2014-04-01

376

24 CFR 3280.705 - Gas piping systems.  

Code of Federal Regulations, 2010 CFR

...B36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded brass pipe in iron...may be used. Threaded brass pipe shall comply with ASTM B43-91, Standard Specification for Seamless Red Brass Pipe, Standard Sizes....

2010-04-01

377

24 CFR 3280.706 - Oil piping systems.  

Code of Federal Regulations, 2011 CFR

...Steel or wrought-iron pipe shall comply with ANSI B 36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded copper or brass pipe in iron pipe sizes may be used. ...Standard Specification for Seamless Copper Water Tube,...

2011-04-01

378

24 CFR 3280.706 - Oil piping systems.  

Code of Federal Regulations, 2012 CFR

...Steel or wrought-iron pipe shall comply with ANSI B 36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded copper or brass pipe in iron pipe sizes may be used. ...Standard Specification for Seamless Copper Water Tube,...

2012-04-01

379

24 CFR 3280.706 - Oil piping systems.  

Code of Federal Regulations, 2013 CFR

...Steel or wrought-iron pipe shall comply with ANSI B 36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded copper or brass pipe in iron pipe sizes may be used. ...Standard Specification for Seamless Copper Water Tube,...

2013-04-01

380

24 CFR 3280.705 - Gas piping systems.  

Code of Federal Regulations, 2011 CFR

...B36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded brass pipe in iron...may be used. Threaded brass pipe shall comply with ASTM B43-91, Standard Specification for Seamless Red Brass Pipe, Standard Sizes....

2011-04-01

381

Cryogenic thermal diode heat pipes  

NASA Technical Reports Server (NTRS)

The development of spiral artery cryogenic thermal diode heat pipes was continued. Ethane was the working fluid and stainless steel the heat pipe material in all cases. The major tasks included: (1) building a liquid blockage (blocking orifice) thermal diode suitable for the HEPP space flight experiment; (2) building a liquid trap thermal diode engineering model; (3) retesting the original liquid blockage engineering model, and (4) investigating the startup dynamics of artery cryogenic thermal diodes. An experimental investigation was also conducted into the wetting characteristics of ethane/stainless steel systems using a specially constructed chamber that permitted in situ observations.

Alario, J.

1979-01-01

382

High performance flexible heat pipes  

NASA Technical Reports Server (NTRS)

A Phase I SBIR NASA program for developing and demonstrating high-performance flexible heat pipes for use in the thermal management of spacecraft is examined. The program combines several technologies such as flexible screen arteries and high-performance circumferential distribution wicks within an envelope which is flexible in the adiabatic heat transport zone. The first six months of work during which the Phase I contract goal were met, are described. Consideration is given to the heat-pipe performance requirements. A preliminary evaluation shows that the power requirement for Phase II of the program is 30.5 kilowatt meters at an operating temperature from 0 to 100 C.

Shaubach, R. M.; Gernert, N. J.

1985-01-01

383

Laboratory evaluation of the Pipe Explorer{trademark} gamma measurement and deployment capability  

SciTech Connect

The DOE is faced with the responsibility of decommissioning and dismantling many of its nuclear process facilities. Much of this will involve piping systems which may or may not be contaminated with radioactive material. It is important to be able to differentiate contaminated from non-contaminated material, since the disposal costs for radioactive waste are significant (on the order of hundreds of dollars per cubic foot). In the case of pipes, this determination may be particularly difficult if the pipes are not easily accessible. As a solution to this problem, SEA is developing an inverting membrane technology, called Pipe Explorer{trademark} which uses commercial gamma spectroscopy systems to characterize the radiation levels inside of pipes. The heart of the system is an air-tight membrane which is initially spooled inside of a canister. The end of the membrane protruding out of the canister is folded over and attached to a basepipe. With this configuration, when the canister becomes pressurized the pressure force on the membrane causes the membrane to be pulled from the spool. This continues until the membrane is completely off the spool. A radiation detector is attached to the end of the membrane and towed into the pipe as the membrane continues to evert. The detector cabling is also towed into the pipe. To retrieve the system from a pipe the process is simply reversed, where the cabling, detector, and membrane are wound back onto the spool. The system can thus be used to move a detector freely back and forth through a pipe to provide high resolution analysis of the location of radioactive contamination in pipes. This unique method can deploy the detector and analyze piping systems with multiple elbows and vertical runs. The membrane also serves to protect the expensive detector from contamination.

Cremer, C.D.; Cramer, E.; Lowry, W.

1994-08-01

384

Benchmarking: A tool to enhance performance  

SciTech Connect

The Office of Environmental Management is bringing Headquarters and the Field together to implement process improvements throughout the Complex through a systematic process of organizational learning called benchmarking. Simply stated, benchmarking is a process of continuously comparing and measuring practices, processes, or methodologies with those of other private and public organizations. The EM benchmarking program, which began as the result of a recommendation from Xerox Corporation, is building trust and removing barriers to performance enhancement across the DOE organization. The EM benchmarking program is designed to be field-centered with Headquarters providing facilitatory and integrative functions on an ``as needed`` basis. One of the main goals of the program is to assist Field Offices and their associated M&O/M&I contractors develop the capabilities to do benchmarking for themselves. In this regard, a central precept is that in order to realize tangible performance benefits, program managers and staff -- the ones closest to the work - must take ownership of the studies. This avoids the ``check the box`` mentality associated with some third party studies. This workshop will provide participants with a basic level of understanding why the EM benchmarking team was developed and the nature and scope of its mission. Participants will also begin to understand the types of study levels and the particular methodology the EM benchmarking team is using to conduct studies. The EM benchmarking team will also encourage discussion on ways that DOE (both Headquarters and the Field) can team with its M&O/M&I contractors to conduct additional benchmarking studies. This ``introduction to benchmarking`` is intended to create a desire to know more and a greater appreciation of how benchmarking processes could be creatively employed to enhance performance.

Munro, J.F. [Oak Ridge National Lab., TN (United States); Kristal, J. [USDOE Assistant Secretary for Environmental Management, Washington, DC (United States); Thompson, G.; Johnson, T. [Los Alamos National Lab., NM (United States)

1996-12-31

385

TORT solutions for the 3D radiation transport benchmarks for simple geometries with void region  

Microsoft Academic Search

We present the solutions for the set of three-dimensional radiation transport Benchmark problems obtained with the TORT transport code using its three optional methods: Theta Weighted (?W), Linear Nodal (LN), and Linear Characteristic (LC). Only the cases with 50% scattering are presented in this paper since the nonscattering cases are bound to suffer severe ray effects. By solving the problems

Yousry Y. Azmy; Franz X. Gallmeier; Dick A. Lillie

2001-01-01

386

46 CFR 154.660 - Pipe welding.  

Code of Federal Regulations, 2014 CFR

...of this chapter. (b) Longitudinal butt welds, in piping that does not meet a standard or...56.60-1 of this chapter, and girth butt welds must meet the following: (1) Butt welds of pipes made from carbon, carbon...

2014-10-01

387

46 CFR 154.660 - Pipe welding.  

Code of Federal Regulations, 2013 CFR

...of this chapter. (b) Longitudinal butt welds, in piping that does not meet a standard or...56.60-1 of this chapter, and girth butt welds must meet the following: (1) Butt welds of pipes made from carbon, carbon...

2013-10-01

388

Flat heat pipe design, construction, and analysis  

SciTech Connect

This paper details the design, construction and partial analysis of a low temperature flat heat pipe in order to determine the feasibility of implementing flat heat pipes into thermophotovoltaic (TPV) energy conversion systems.

Voegler, G.; Boughey, B.; Cerza, M.; Lindler, K.W.

1999-08-02

389

A benchmark model to assess community structure in evolving networks  

E-print Network

Detecting the time evolution of the community structure of networks is crucial to identify major changes in the internal organization of many complex systems, which may undergo important endogenous or exogenous events. This analysis can be done in two ways: considering each snapshot as an independent community detection problem or taking into account the whole evolution of the network. In the first case, one can apply static methods on the temporal snapshots, which correspond to configurations of the system in short time windows, and match afterwards the communities across layers. Alternatively, one can develop dedicated dynamic procedures, so that multiple snapshots are simultaneously taken into account while detecting communities, which allows to keep memory of the flow. To check how well a method of any kind could capture the evolution of communities, suitable benchmarks are needed. Here we propose a model for generating simple dynamic benchmark graphs, based on stochastic block models. In them, the time e...

Granell, Clara; Arenas, Alex; Fortunato, Santo; Gómez, Sergio

2015-01-01

390

Benchmarking Database Systems A Systematic Approach  

Microsoft Academic Search

This paper describes a customized database and a comprehensive set of queries that can be used for systematic benchmarking of relational database systems. Designing this database and a set of carefully tuned benchmarks represents a first attempt in developing a scientific methodology for performance evaluation of database management systems. We have used this database to perform a comparative evaluation of

Dina Bitton; David J. Dewitt; Carolyn Turbyfill

1983-01-01

391

Benchmarking Database Systems A Systematic Approach  

E-print Network

Benchmarking Database Systems A Systematic Approach Dina Bitton David J. DeWitt Carolyn Turbyfill-81ER10920. #12;ABSTRACT This paper describes a customized database and a comprehensive set of queries that can be used for sys- tematic benchmarking of relational database systems. Designing this database

Liblit, Ben

392

A Benchmark Diagnostic Model Generation System  

Microsoft Academic Search

It is critical to use automated generators for synthetic models and data given the sparsity of benchmark models for empirical analysis and the cost of generating models by hand. We describe an automated generator for benchmark models that is based on using a compositional modeling framework and employs graphical models for the system topology. We propose a three-step process for

Jun Wang; Gregory M. Provan

2010-01-01

393

The PRISM Benchmark Suite Marta Kwiatkowska  

E-print Network

The PRISM Benchmark Suite Marta Kwiatkowska Department of Computer Science, University of Oxford.a.parker@cs.bham.ac.uk Abstract--We present the PRISM benchmark suite: a col- lection of probabilistic models and property of which is the PRISM model checker [1]. Many models for use with PRISM are publicly available, either

Paris-Sud XI, Université de

394

Best practice benchmarking: a route to competitiveness?  

Microsoft Academic Search

This paper examines the use of best practice benchmarking as an approach to performance improvement in the airline industry. The case study draws upon phenomenological evidence from the aircraft maintenance section of Britannia Airways. A range of benchmarking issues, which could be applied to different divisions of an airline are highlighted. In particular, inter disciplinary team building, employee involvement, relationships

Graham Francis; Matthew Hinton; Jacky Holloway; Ian Humphreys

1999-01-01

395

The ISPD98 circuit benchmark suite  

Microsoft Academic Search

From 1985-1993, the MCNC regularly introduced and maintained circuit benchmarks for use by the Design Automation community. However, during the last five years, no new circuits have been introduced that can be used for developing fundamental physical design applications, such as partitioning and placement. The largest circuit in the existing set of benchmark suites has over 100,000 modules, but the

Charles J. Alpert

1998-01-01

396

Benchmark Assessment for Improved Learning. AACC Report  

ERIC Educational Resources Information Center

This report describes the purposes of benchmark assessments and provides recommendations for selecting and using benchmark assessments--addressing validity, alignment, reliability, fairness and bias and accessibility, instructional sensitivity, utility, and reporting issues. We also present recommendations on building capacity to support schools'…

Herman, Joan L.; Osmundson, Ellen; Dietel, Ronald

2010-01-01

397

A parallel java grande benchmark suite  

Microsoft Academic Search

Increasing interest is being shown in the use of Java for large scale or Grande applications. This new use of Java places specific demands on the Java execution environments that can be tested using the Java Grande benchmark suite [5], [6], [7]. The large processing requirements of Grande applications makes parallelisation of interest. A suite of parallel benchmarks has been

L. A. Smith; J. Mark Bull; J. Obdrzálek

2001-01-01

398

DPF: A Data Parallel Fortran Benchmark Suite  

Microsoft Academic Search

We present the Data Parallel Fortran (DPF) benchmark suite, a set of data parallel Fortran codes for evaluating data parallel compilers appropriate for any target parallel archi- tecture, with shared or distributed memory. The codes are provided in basic, optimized and several library versions. The functionality of the benchmarks cover collective commu- nication functions, scientific software library functions, and application

Y. Charlie Hu; S. Lennart Johnsson; Dimitris Kehagias; Nadia Shalaby

1997-01-01

399

DPF: A Data Parallel Fortran Benchmark Suite  

Microsoft Academic Search

The Data Parallel Fortran (DPF) benchmark suite is designed for evaluating data parallelcompilers and scalable architectures. Many of the DPF codes are provided in three versions:basic, optimized and with library calls for performance critical operations typically foundin software libraries. The functionality of the benchmarks cover collective communicationfunctions, scientific software library functions, and application kernels that reflect the computationalstructure and...

Nadia Shalaby; Dimitris Kehagias; S. Lennart Johnsson; Yu Hu

1995-01-01

400

Parallel benchmarks on the Transtech Paramid  

Microsoft Academic Search

This paper presents the results of running the some benchmarks from the Genesis suite on the Transtech Paramid. The benchmarks use the PARMACS parallel processing standard, and are based on applications in the fields of general relativity, molecular dynamics and QCD. The Paramid is a distributed memory parallel computer, using up to 64 Intel i860-XP processors. The results demonstrate good

R. S. Stephens

1994-01-01

401

A Parallel Java Grande Benchmark Suite  

Microsoft Academic Search

Increasing interest is being shown in the use of Java for large scale or Grande applications. This new use of Java places speci.c demands on the Java execution environments that can be tested using the Java Grande benchmark suite [5], [6], [7]. The large processing requirements of Grande applications makes parallelisation of interest. A suite of parallel benchmarks has been

L. A. Smith; J. M. Bull; J. Obdrizalek

2001-01-01

402

DARPA February 1992 ATIS benchmark test results  

Microsoft Academic Search

This paper documents the third in a series of Benchmark Tests for the DARPA Air Travel Information System (ATIS) common task domain. The first results in this series were reported at the June 1990 Speech and Natural Language Workshop [1], and the second at the February 1991 Speech and Natural Language Workshop [2]. The February 1992 Benchmark Tests include: (1)

David S. Pallett; Nancy L. Dahlgren; Jonathan G. Fiscus; William M. Fisher; John S. Garofolo; Brett C. Tjaden

1992-01-01

403

Beyond Benchmarking: Value-Adding Metrics  

ERIC Educational Resources Information Center

HR metrics has grown up a bit over the past two decades, moving away from simple benchmarking practices and toward a more inclusive approach to measuring institutional performance and progress. In this article, the acknowledged "father" of human capital performance benchmarking provides an overview of several aspects of today's HR metrics…

Fitz-enz, Jac

2007-01-01

404

The Rat's Life benchmark: competing cognitive robots  

Microsoft Academic Search

This paper describes Rat's Life: a complete cognitive robotics benchmark that was carefully designed to be easily reproducible in a research lab with limited resources. It relies on two e-puck robots, some LEGO bricks and the Webots robot simulation software. This benchmark is a survival game where two robots compete against each other for resources in an unknown maze. Like

Olivier Michel; Fabien Rohrer

2008-01-01

405

Development of gprs-based leak detection system for pipe pushing crossing part of nature gas pipeline  

Microsoft Academic Search

There would be a sealed space, called culvert box, between the nature gas pipeline and the concrete pipe when the nature gas pipeline crossing highways, railways and rivers using the trenchless pipe pushing technology. To deal with the problem of leak detection and monitoring for these culvert boxes, which were located in the field and scattered, a GPRS-based (GPRS: general

Fujun Liu; Shuai Kong; Zhangwei Ling; Mulin Zheng; Yueqiang Qian

2011-01-01

406

Mathematical Model of the Optimum Heat Pipe Heat Exchanger for a Condenser of Vapor-Compression Refrigeration Cycle  

Microsoft Academic Search

Problem statement: This study theoretically investigated applying heat pipe as a heat exchanger in the condenser of vapor compression refrigeration system for sustainable well-being. Split- type air conditioner for residential propose was co nsidered. To reduce pressure drop and recover heat from the condensing process of the refrigeration cy cle, this investigation tried to use Closed Loop Oscillating Heat Pipe

P. Yeunyongkul; P. Sakulchangsatjatai; P. Terdto

2010-01-01

407

Optimizing pipe deformation in a reduction mill  

Microsoft Academic Search

The typical manufacturing technology for general- purpose pipe includes rolling and subsequent normal- ization with separate heating. This is associated with additional heating costs and relatively poor pipe perfor- mance. The use of thermomechanical treatment in the pro- duction of seamless pipe both reduces the cost and improves the mechanical properties. Accordingly, the introduction of this technology is a high

L. G. Marchenko

2008-01-01

408

The magnetic properties of seamless steel pipe  

Microsoft Academic Search

The magnetic and metallurgical properties of seamless pipe steel have been investigated as a function of position around the pipe circumference. No changes in magnetic properties were found to be associated with the four cycle spiral variations in pipe wall thickness introduced during forging. A weaker single cycle thickness variation was accompanied by a change both in magnetic properties and

S. N. M. Willcock; B. K. Tanner; P. A. Mundell

1987-01-01

409

NEUTRON STREAMING IN DâO PIPES  

Microsoft Academic Search

An investigation wae carried out concerning the attenuation of neutrons ; inside DâO-filled pipes penetrating a concrete shield. Pipes surrounded by ; an annular air gap were also considered. Thermal, epithermal, and fast neutron ; fluxes were raeasured in three separate pipes (15, 22, and 28 cm in diameter and ; 100 cm long) with annulii ranging from 0 to

J. Braun; K. Randen

1962-01-01

410

49 CFR 192.59 - Plastic pipe.  

Code of Federal Regulations, 2010 CFR

... 3 2010-10-01 2010-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation...FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe is qualified for use under this part...

2010-10-01

411

49 CFR 192.59 - Plastic pipe.  

Code of Federal Regulations, 2011 CFR

... 3 2011-10-01 2011-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation...FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe is qualified for use under this part...

2011-10-01

412

Bag Test Measures Leakage From Insulated Pipe  

NASA Technical Reports Server (NTRS)

Test quantifies leakage of gas from pipe even though pipe covered with insulation. Involves use of helium analyzer to measure concentration of helium in impermeable bag around pipe. Test administered after standard soap-solution bubble test indicates presence and general class of leakage.

Schock, Kent D.; Easter, Barry P.

1994-01-01

413

Transient heat pipe response and rewetting behavior  

Microsoft Academic Search

This paper describes the results of an investigation of pulsed heat pipe start up. Two types of pulsed start up of a copper and water heat pipe are examined. In the first, the mean temperature of the transport section is nearly constant with time. In the second, the entire heat pipe is increasing in temperature, so thermal energy storage is

J. H. Ambrose; L. C. Chow; J. E. Beam

1986-01-01

414

Development of a cryogenic heat pipe  

Microsoft Academic Search

Heat pipe operating characteristics can be used to advantage in cryogenic systems. Diode operation of the heat pipe, the ability to conduct heat in one direction only, is useful in protecting the heat load if the heat sink temperature rises above the load temperature. Because of this, the heat pipe can be made to act as a thermal switch. A

F. C. Prenger; W. F. Stewart; J. E. Runyan

1993-01-01

415

The THROHPUT code: Thermohydraulic heat pipe modeling  

Microsoft Academic Search

The THROHPUT code is a special purpose transient thermodynamic model of high temperature liquid-metal heat pipe response (THROHPUT is an acronym for Thermal Hydraulic Response Of Heat Pipes Under Transients). A special purpose code like THROHPUT is needed due to the complex nature and interconection of the physical processes occurring in the operation of a heat pipe with the working

Michael L. Hall; Joseph M. Doster

1988-01-01

416

49 CFR 195.424 - Pipe movement.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Pipe movement. 195.424 Section...Maintenance § 195.424 Pipe movement. (a) No operator may move any line pipe, unless the pressure in the...liquid state with continuous flow, but not less than 50...

2013-10-01

417

49 CFR 195.424 - Pipe movement.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Pipe movement. 195.424 Section...Maintenance § 195.424 Pipe movement. (a) No operator may move any line pipe, unless the pressure in the...liquid state with continuous flow, but not less than 50...

2014-10-01

418

49 CFR 195.424 - Pipe movement.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Pipe movement. 195.424 Section...Maintenance § 195.424 Pipe movement. (a) No operator may move any line pipe, unless the pressure in the...liquid state with continuous flow, but not less than 50...

2012-10-01

419

49 CFR 195.424 - Pipe movement.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Pipe movement. 195.424 Section...Maintenance § 195.424 Pipe movement. (a) No operator may move any line pipe, unless the pressure in the...liquid state with continuous flow, but not less than 50...

2011-10-01

420

Two-dimensional rotating heat pipe analysis  

Microsoft Academic Search

A detailed transient numerical simulation of rotating heat pipes is presented. This two-dimensional, axisymmetric formulation accounts for the thin liquid condensate film on the inner surface of the rotating pipe wall, the vapor flow in the vapor space, and the unsteady heat conduction in the pipe wall. The thin liquid film is coupled to the vapor velocity at the liquid-vapor

C. Harley; A. Faghri

1995-01-01

421

The locating ways of laying pipe manipulator  

NASA Astrophysics Data System (ADS)

The laying pipe manipulator is a new equipment to lay concrete pipe. This kind of manipulator makes the work of laying pipes mechanized and automated. We report here a new laying pipe manipulator. The manipulator has 5 free degrees, and is driven by the hydraulic system. In the paper, one critical question of manipulator is studied: the locating ways of the manipulator to lay concrete pipe. During the process of laying concrete pipe, how to locate the manipulator is realized by the locating system of manipulator. The locating system consists of photoelectric target, laser producer, and computer. According to different construction condition, one or two or three photoelectric targets can be used. During the process of laying concrete pipe, if the interface of pipes are jointed together, and the other segment of pipe deviates from the pipe way, one target can be used, if the angle that the manipulator rotates around the holding pipe's axes is 0°, two targets can be used, three targets can be used at any site. In the paper, according to each locating way, the theory analysis is done. And the mathematical models of the manipulator moving from original position to goal position are obtained by different locating way. And the locating experiment was done. According to the experiment result, the work principle and mathematical models of different locating way was turned out to be well adopted for requirement, the mathematical model of different locating way supplies the basic control theory for the manipulator to lay and joint concrete pipe automatically.

Wang, Dan; Li, Bin; Lei, Dongliang

2009-12-01

422

The locating ways of laying pipe manipulator  

NASA Astrophysics Data System (ADS)

The laying pipe manipulator is a new equipment to lay concrete pipe. This kind of manipulator makes the work of laying pipes mechanized and automated. We report here a new laying pipe manipulator. The manipulator has 5 free degrees, and is driven by the hydraulic system. In the paper, one critical question of manipulator is studied: the locating ways of the manipulator to lay concrete pipe. During the process of laying concrete pipe, how to locate the manipulator is realized by the locating system of manipulator. The locating system consists of photoelectric target, laser producer, and computer. According to different construction condition, one or two or three photoelectric targets can be used. During the process of laying concrete pipe, if the interface of pipes are jointed together, and the other segment of pipe deviates from the pipe way, one target can be used, if the angle that the manipulator rotates around the holding pipe's axes is 0°, two targets can be used, three targets can be used at any site. In the paper, according to each locating way, the theory analysis is done. And the mathematical models of the manipulator moving from original position to goal position are obtained by different locating way. And the locating experiment was done. According to the experiment result, the work principle and mathematical models of different locating way was turned out to be well adopted for requirement, the mathematical model of different locating way supplies the basic control theory for the manipulator to lay and joint concrete pipe automatically.

Wang, Dan; Li, Bin; Lei, DongLiang

2010-01-01

423

Calculate the heat loss from pipes  

Microsoft Academic Search

Heat lost from piped fluids is energy wasted. Even a fluid-temperature drop of 1 C or less from the pipe's inlet to its outlet is a sign of heat loss. This raises energy costs because heat must usually be added back to the fluid later. If the pipe-wall temperature is not unduly high, convection can be assumed to be the

Konak

1993-01-01

424

ECTFE lined steel pipe is trouble-free with oleum  

SciTech Connect

Penreco, a division of Pennzoil Company in Karns City, PA, makes a variety of specialty petroleum products including white mineral oils and petroleum jellies for cosmetics and pharmaceuticals, and solvents for printing inks. A 2'' carbon steel transfer line failed repeatedly due to corrosion. A fluoropolymer--lined steel piping system was installed in 1983. The straight spool pieces were lined with a fluoropolymer that exhibits excellent resistance to a wide range of aggressive chemicals at temperatures to 450/sup 0/F. The elbows and tees were lined with ECTFE, a copolymer of ethylene (E) and chlorotrifluoroethylene (CTFE). The thermoplastic offers the same resistance to attack by chemicals and solvents as TFE, but is more resistant to abrasion, flexing and permeation by gases and liquids. About a year after the lined piping system was installed, the flanges began to leak. The problem was identified as embrittlement of the fluoropolymer used to line the spool pieces, which resulted in cracks and fissures in the integral flared flange gasket. Embrittlement and stress cracking may have been caused by free SO/sub 2/ reacting with the polymer. The flange faces of ECTFE were intact, and the lining showed no signs of corrosion or erosion by the aggressive media. In July 1984, the leaking pipe sections were replaced with new spool pieces lined with ECTFE, since the fittings lined with this material were still in excellent condition. The fittings were not replaced. The spent acid piping system, with both fittings and straight sections lines with ECTFE, has been trouble-free since July 1984. The superior permeation resistance of the fluoropolymer also enhances the integrity and service life of the steel pipe by eliminating the need for weepholes to prevent a build-up of gases and liquids, between the liner OD and pipe ID.

Powers, B.; Gaines, A.

1986-10-01

425

Thermal Performance of High Temperature Titanium - Water Heat Pipes by Multiple Heat Pipe Manufacturers  

NASA Astrophysics Data System (ADS)

Titanium - water heat pipes are being investigated for use in heat rejection systems for lunar and Mars fission surface power systems. Heat pipes provide an efficient and reliable means to transfer heat to a radiator heat rejection system. NASA Glenn Research Center requisitioned nine titanium water heat pipes from three vendors. Each vendor supplied three heat pipes 1.25 cm diameter by 1.1 meter long with each vendor selecting a different wick design. Each of the three heat pipes is slightly different in construction. Additional specifications for the heat pipes included 500 K nominal operating temperature, light weight, and freeze tolerance. The heat pipes were performance tested gravity aided, in the horizontal position and elevations against gravity at 450 K and 500 K. Performance of the three heat pipes is compared. The heat pipe data will be used to verify models of heat pipe radiators that will be used in future space exploration missions.

Sanzi, James L.

2007-01-01

426

Thermal Performance of High Temperature Titanium-Water Heat Pipes by Multiple Heat Pipe Manufacturers  

NASA Technical Reports Server (NTRS)

Titanium-water heat pipes are being investigated for use in heat rejection systems for lunar and Mars fission surface power systems. Heat pipes provide an efficient and reliable means to transfer heat to a radiator heat rejection system. NASA Glenn Research Center requisitioned nine titanium water heat pipes from three vendors. Each vendor supplied three heat pipes 1.25 cm diameter by 1.1 meter long with each vendor selecting a different wick design. Each of the three heat pipes is slightly different in construction. Additional specifications for the heat pipes included 500 K nominal operating temperature, light weight, and freeze tolerance. The heat pipes were performance tested gravity-aided, in the horizontal position and at elevations against gravity at 450 and 500 K. Performance of the three heat pipes is compared. The heat pipe data will be used to verify models of heat pipe radiators that will be used in future space exploration missions.

Sanzi, James L.

2007-01-01

427

Thermal Performance of High Temperature Titanium -- Water Heat Pipes by Multiple Heat Pipe Manufacturers  

NASA Technical Reports Server (NTRS)

Titanium - water heat pipes are being investigated for use in heat rejection systems for lunar and Mars fission surface power systems. Heat pipes provide an efficient and reliable means to transfer heat to a radiator heat rejection system. NASA Glenn Research Center requisitioned nine titanium water heat pipes from three vendors. Each vendor supplied three heat pipes 1.25 cm diameter by 1.1 meter long with each vendor selecting a different wick design. Each of the three heat pipes is slightly different in construction. Additional specifications for the heat pipes included 500 K nominal operating temperature, light weight, and freeze tolerance. The heat pipes were performance tested gravity-aided, in the horizontal position and at elevations against gravity at 450 K and 500 K. Performance of the three heat pipes is compared. The heat pipe data will be used to verify models of heat pipe radiators that will be used in future space exploration missions.

Sanzi, James L.

2007-01-01

428

Heat pipe dynamics. Final report, April 30, 1981. [Uses of heat pipe, especially in solar collector  

SciTech Connect

A heat-pipe flat plate solar collector is constructed like a typical flat plate collector with the exception that individual heat pipes are attached to the collector surface to transfer collected heat via a phase change from collector surface into an attached jacket containing a phase change material. The efficiency of such a collector was measured roughly. Also briefly described are: a heat-pipe heat exchanger, heat-pipe heat exchanger freeze proofing, heat-pipe attic ventilation, transfer of light bulb heat via a heat pipe to heat water, heat recovery via heat pipe, cooling of oil in engines and transmissions via heat pipe, a tracking reflector, automatic sun tracker, single-stroke vacuum pump for heat-pipe manufacture, and heat pipe heat transfer from rock bed. (LEW)

Norman, R.M. Sr.

1981-01-01

429

Steam bubble collapse, water hammer and piping network response. Volume I. Steam bubble collapse and water hammer in piping systems: experiments and analysis. Final report  

Microsoft Academic Search

Water hammer incidents in conventional and nuclear steam systems are an important problem of broad general interest in piping network design and transient operation. Water hammer in PWR steam generator sparger feed lines has, for example, been a recurrent problem when the sparger becomes uncovered during certain operational transients (Creare 1977). The central goal of this research has been to

R. Gruel; W. Hurwitz; P. Huber; P. Griffith

1980-01-01

430

29 CFR 1952.203 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.203 Section 1952.203... § 1952.203 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall, compliance staffing levels (benchmarks) necessary for a “fully...

2014-07-01

431

29 CFR 1952.323 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.323 Section 1952.323... § 1952.323 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall compliance staffing levels (benchmarks) necessary for a “fully...

2014-07-01

432

29 CFR 1952.93 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.93 Section 1952.93 ...§ 1952.93 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall compliance staffing levels (benchmarks) necessary for a “fully...

2014-07-01

433

29 CFR 1952.233 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.233 Section 1952.233... § 1952.233 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall compliance staffing levels (benchmarks) necessary for a “fully...

2014-07-01

434

29 CFR 1952.153 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.153 Section 1952.153... § 1952.153 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall, compliance staffing levels (“benchmarks”) necessary for a “fully...

2014-07-01

435

29 CFR 1952.223 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.223 Section 1952.223... § 1952.223 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall compliance staffing levels (benchmarks) necessary for a “fully...

2014-07-01

436

29 CFR 1952.363 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.363 Section 1952.363... § 1952.363 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall, compliance staffing levels (“benchmarks”) necessary for a “fully...

2014-07-01

437

29 CFR 1952.343 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.343 Section 1952.343... § 1952.343 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall, Compliance staffing levels (benchmarks) necessary for a “fully...

2014-07-01

438

29 CFR 1952.163 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.163 Section 1952.163... § 1952.163 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall, compliance staffing levels (benchmarks) necessary for a “fully...

2014-07-01

439

45 CFR 156.100 - State selection of benchmark.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false State selection of benchmark. 156.100 Section 156.100 Public...Package § 156.100 State selection of benchmark. Each State may identify a single EHB-benchmark plan according to the selection...

2014-10-01

440

29 CFR 1952.293 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.293 Section 1952.293... § 1952.293 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall compliance staffing levels (benchmarks) necessary for a “fully...

2014-07-01

441

29 CFR 1952.353 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Compliance staffing benchmarks. 1952.353 Section 1952.353... § 1952.353 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall, compliance staffing levels (benchmarks) necessary for a “fully...

2014-07-01

442

42 CFR 422.258 - Calculation of benchmarks.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Calculation of benchmarks. 422.258 Section 422.258...Approval § 422.258 Calculation of benchmarks. (a) The term “MA area-specific non-drug monthly benchmark amount” means, for a month in...

2010-10-01

443

Characterizing Microprocessor Benchmarks Towards Understanding the Workload Design Space  

E-print Network

#12;Characterizing Microprocessor Benchmarks Towards Understanding the Workload Design Space The University of Texas at Austin December 2003 #12;Characterizing Microprocessor Benchmarks Towards #12;Characterizing Microprocessor Benchmarks Towards Understanding the Workload Design Space

John, Lizy Kurian

444

SP2Bench: A SPARQL Performance Benchmark  

NASA Astrophysics Data System (ADS)

A meaningful analysis and comparison of both existing storage schemes for RDF data and evaluation approaches for SPARQL queries necessitates a comprehensive and universal benchmark platform. We present SP2Bench, a publicly available, language-specific performance benchmark for the SPARQL query language. SP2Bench is settled in the DBLP scenario and comprises a data generator for creating arbitrarily large DBLP-like documents and a set of carefully designed benchmark queries. The generated documents mirror vital key characteristics and social-world distributions encountered in the original DBLP data set, while the queries implement meaningful requests on top of this data, covering a variety of SPARQL operator constellations and RDF access patterns. In this chapter, we discuss requirements and desiderata for SPARQL benchmarks and present the SP2Bench framework, including its data generator, benchmark queries and performance metrics.

Schmidt, Michael; Hornung, Thomas; Meier, Michael; Pinkel, Christoph; Lausen, Georg

445

Lawrence Livermore plutonium button critical experiment benchmark  

SciTech Connect

The end of the Cold War and the subsequent weapons reductions have led to an increased need for the safe storage of large amounts of highly enriched plutonium. In support of code validation required to address this need, a set of critical experiments involving arrays of weapons-grade plutonium metal that were performed at the Lawrence Livermore National Laboratory (LLNL) in the late 1960s has been revisited. Although these experiments are well documented, discrepancies and omissions have been found in the earlier reports. Many of these have been resolved in the current work, and these data have been compiled into benchmark descriptions. In addition, a computational verification has been performed on the benchmarks using multiple computer codes. These benchmark descriptions are also being made available to the US Department of Energy (DOE)-sponsored Nuclear Criticality Safety Benchmark Evaluation Working Group for dissemination in the DOE Handbook on Evaluated Criticality Safety Benchmark Experiments.

Trumble, E.F.; Justice, J.B.; Frost, R.L.

1994-12-31

446

Forming of seamless pipe fittings  

Microsoft Academic Search

Analysis and results of the high temperature forming of seamless pipe fittings produced at a local factory are presented in this work. The studies were conducted by recording the thermal evolution in different parts of the piece as it was being forged, which was done by placing a series of type K thermocouples within the part and logging the data

Andrés Rodr??guez; Margarita Mezzetti; Peter Fodor; Rafael Colás

2002-01-01

447

Pipe Leak Detection Technology Development  

EPA Science Inventory

The U. S. Environmental Protection Agency (EPA) has determined that one of the nation?s biggest infrastructural needs is the replacement or rehabilitation of the water distribution and transmission systems. The institution of more effective pipe leak detection technology will im...

448

Modeling of pulsating heat pipes  

Microsoft Academic Search

This report summarizes the results of a computer model that describes the behavior of pulsating heat pipes (PHP). The purpose of the project was to develop a highly efficient (as compared to the heat transfer capability of solid copper) thermal groundplane (TGP) using silicon carbide (SiC) as the substrate material and water as the working fluid. The objective of this

Richard C. Givler; Mario J. Martinez

2009-01-01

449

Transient thermohydraulic heat pipe modeling  

Microsoft Academic Search

Many space based reactor designs employ heat pipes as a means of conveying heat. In these designs, thermal radiation is the principle means for rejecting waste heat from the reactor system, making it desirable to operate at high temperatures. Lithium is generally the working fluid of choice as it undergoes a liquid-vapor transformation at the preferred operating temperature. The nature

Michael L. Hall; Joseph M. Doster

1987-01-01

450

Welding HSLA line pipe steels  

Microsoft Academic Search

This paper has reviewed the various aspects of weldability as it is influenced by the base metal composition and processing in HSLA line pipe steels. The Mo-Nb steels meet these stringent weldability requirements. Consumables have been developed for both girth and seam welding the Mo-Nb steels, and the strength and toughness required for severe service can be obtained with consumables

J. M. Sawhill

1977-01-01

451

Pump assisted heat pipe system  

NASA Astrophysics Data System (ADS)

A laboratory model of a pump assisted heat pipe has been fabricated and tested in order to assess the potential for advanced thermal systems for future spacecraft. New arterial heat pipes with axial grooves and gear pump driven through a magnetic coupling have been developed for this purpose and two sets of heat pipe, 0.2 m and 1 m models, have been prepared. Component tests for the heat pipes have been carried out and its heat transfer characteristics, especially the dry-out phenomenon, are discussed. This system test revealed that the condition for stable operation without anomalous loop behavior can be established, and it is found that excess working fluid flow rate is needed in order to avoid dry-out at high heat flux condition. In the accumulator pressure test, it is seen that the thermal conductance of the condenser varies so as to keep the system vapor pressure same as that in the accumulator. This is due to liquid blockage in the condenser and it would provide an effective means of controlling temperature through the accumulator pressure regulated externally.

Miyazaki, Y.; Oshima, S.; Furukawa, M.; Imai, R.

1988-06-01

452

Traveling Waves in Pipe Flow  

Microsoft Academic Search

A family of three-dimensional traveling waves for flow through a pipe of circular cross section is identified. The traveling waves are dominated by pairs of downstream vortices and streaks. They originate in saddle-node bifurcations at Reynolds numbers as low as 1250. All states are immediately unstable. Their dynamical significance is that they provide a skeleton for the formation of a

Holger Faisstand; Bruno Eckhardt

2003-01-01

453

Hydrogen Piping Experience in Chevron  

E-print Network

experienced engineers Many of our practices such as bridge welding are effectively aimed at preventing fatigue commonly SA 333 Gr6); may call for A672 (specific grades) electric-fusion-welded pipe for sizes >16" 100% radiographic examination required for all welds Postweld Heat Treatment requirements as a function of thickness

454

NASA Software Engineering Benchmarking Study  

NASA Technical Reports Server (NTRS)

To identify best practices for the improvement of software engineering on projects, NASA's Offices of Chief Engineer (OCE) and Safety and Mission Assurance (OSMA) formed a team led by Heather Rarick and Sally Godfrey to conduct this benchmarking study. The primary goals of the study are to identify best practices that: Improve the management and technical development of software intensive systems; Have a track record of successful deployment by aerospace industries, universities [including research and development (R&D) laboratories], and defense services, as well as NASA's own component Centers; and Identify candidate solutions for NASA's software issues. Beginning in the late fall of 2010, focus topics were chosen and interview questions were developed, based on the NASA top software challenges. Between February 2011 and November 2011, the Benchmark Team interviewed a total of 18 organizations, consisting of five NASA Centers, five industry organizations, four defense services organizations, and four university or university R and D laboratory organizations. A software assurance representative also participated in each of the interviews to focus on assurance and software safety best practices. Interviewees provided a wealth of information on each topic area that included: software policy, software acquisition, software assurance, testing, training, maintaining rigor in small projects, metrics, and use of the Capability Maturity Model Integration (CMMI) framework, as well as a number of special topics that came up in the discussions. NASA's software engineering practices compared favorably with the external organizations in most benchmark areas, but in every topic, there were ways in which NASA could improve its practices. Compared to defense services organizations and some of the industry organizations, one of NASA's notable weaknesses involved communication with contractors regarding its policies and requirements for acquired software. One of NASA's strengths was its software assurance practices, which seemed to rate well in comparison to the other organizational groups and also seemed to include a larger scope of activities. An unexpected benefit of the software benchmarking study was the identification of many opportunities for collaboration in areas including metrics, training, sharing of CMMI experiences and resources such as instructors and CMMI Lead Appraisers, and even sharing of assets such as documented processes. A further unexpected benefit of the study was the feedback on NASA practices that was received from some of the organizations interviewed. From that feedback, other potential areas where NASA could improve were highlighted, such as accuracy of software cost estimation and budgetary practices. The detailed report contains discussion of the practices noted in each of the topic areas, as well as a summary of observations and recommendations from each of the topic areas. The resulting 24 recommendations from the topic areas were then consolidated to eliminate duplication and culled into a set of 14 suggested actionable recommendations. This final set of actionable recommendations, listed below, are items that can be implemented to improve NASA's software engineering practices and to help address many of the items that were listed in the NASA top software engineering issues. 1. Develop and implement standard contract language for software procurements. 2. Advance accurate and trusted software cost estimates for both procured and in-house software and improve the capture of actual cost data to facilitate further improvements. 3. Establish a consistent set of objectives and expectations, specifically types of metrics at the Agency level, so key trends and models can be identified and used to continuously improve software processes and each software development effort. 4. Maintain the CMMI Maturity Level requirement for critical NASA projects and use CMMI to measure organizations developing software for NASA. 5.onsolidate, collect and, if needed, develop common processes principles and other assets across t

Rarick, Heather L.; Godfrey, Sara H.; Kelly, John C.; Crumbley, Robert T.; Wifl, Joel M.

2013-01-01

455

Benchmarking ICRF simulations for ITER  

SciTech Connect

Abstract Benchmarking of full-wave solvers for ICRF simulations is performed using plasma profiles and equilibria obtained from integrated self-consistent modeling predictions of four ITER plasmas. One is for a high performance baseline (5.3 T, 15 MA) DT H-mode plasma. The others are for half-field, half-current plasmas of interest for the pre-activation phase with bulk plasma ion species being either hydrogen or He4. The predicted profiles are used by seven groups to predict the ICRF electromagnetic fields and heating profiles. Approximate agreement is achieved for the predicted heating power partitions for the DT and He4 cases. Profiles of the heating powers and electromagnetic fields are compared.

R. V. Budny, L. Berry, R. Bilato, P. Bonoli, M. Brambilla, R.J. Dumont, A. Fukuyama, R. Harvey, E.F. Jaeger, E. Lerche, C.K. Phillips, V. Vdovin, J. Wright, and members of the ITPA-IOS

2010-09-28

456

The Challenge of Providing Safe Water with an Intermittently Supplied Piped Water Distribution System  

NASA Astrophysics Data System (ADS)

An increasing number of urban residents in low- and middle-income countries have access to piped water; however, this water is often not available continuously. 84% of reporting utilities in low-income countries provide piped water for fewer than 24 hours per day (van den Berg and Danilenko, 2010), while no major city in India has continuous piped water supply. Intermittent water supply leaves pipes vulnerable to contamination and forces households to store water or rely on alternative unsafe sources, posing a health threat to consumers. In these systems, pipes are empty for long periods of time and experience low or negative pressure even when water is being supplied, leaving them susceptible to intrusion from sewage, soil, or groundwater. Households with a non-continuous supply must collect and store water, presenting more opportunities for recontamination. Upgrading to a continuous water supply, while an obvious solution to these challenges, is currently out of reach for many resource-constrained utilities. Despite its widespread prevalence, there are few data on the mechanisms causing contamination in an intermittent supply and the frequency with which it occurs. Understanding the impact of intermittent operation on water quality can lead to strategies to improve access to safe piped water for the millions of people currently served by these systems. We collected over 100 hours of continuous measurements of pressure and physico-chemical water quality indicators and tested over 1,000 grab samples for indicator bacteria over 14 months throughout the distribution system in Hubli-Dharwad, India. This data set is used to explore and explain the mechanisms influencing water quality when piped water is provided for a few hours every 3-5 days. These data indicate that contamination occurs along the distribution system as water travels from the treatment plant to reservoirs and through intermittently supplied pipes to household storage containers, while real-time measurements document variability in water quality throughout the 2-8 hour supply period. Our results show that piped water is not always safe water, but that safe water can be achieved in an intermittent supply under certain physical and operational conditions. Intermittent piped water supply is an important constraint on access to safe water in towns and cities in low-income countries, and strategies that improve these existing systems can help urban residents gain access to safe water. References van den Berg, C., and Danilenko, A. (2010). "The IBNET Water Supply and Sanitation Performance Blue Book: The International Benchmarking Network for Water and Sanitation Utilities Databook." World Bank Washington, DC.

Kumpel, E.; Nelson, K. L.

2012-12-01

457

A numerical analysis of high-temperature heat pipe startup from the frozen state  

NASA Technical Reports Server (NTRS)

Continuum and rarefied vapor flows co-exist along the heat pipe length for most of the startup period. A two-region model is proposed in which the vapor flow in the continuum region is modeled by the compressible Navier-Stokes equations, and the vapor flow in the rarefied region is simulated by a self-diffusion model. The two vapor regions are linked with appropriate boundary conditions, and heat pipe wail, wick, and vapor flow are solved as a conjugate problem. The numerical solutions for the entire heat pipe startup process from the frozen state are compared with the corresponding experimental data with good agreement.

Cao, Y.; Faghri, A.

1993-01-01

458

Radiant heating tests of several liquid metal heat-pipe sandwich panels  

NASA Technical Reports Server (NTRS)

Integral heat-pipe sandwich panels, which synergistically combine the thermal efficiency of heat pipes and the structural efficiency of honeycomb sandwich construction, were conceived as a means of alleviating thermal stress problems in the Langley Scramjet Engine. Test panels which utilized two different wickable honeycomb cores, facesheets with screen mesh sintered to the internal surfaces, and a liquid metal working fluid (either sodium or potassium) were tested by radiant heating at various heat-load levels. The heat-pipe panels reduced maximum temperature differences by 31 percent with sodium working fluid and 45 percent with potassium working fluid. Results indicate that a heat-pipe sandwich panel is a potential, simple solution to the engine thermal stress problem. Other interesting applications of the concept include: cold plates for electronic component and circuit card cooling, radiators for large space platforms, low-distortion large area structures (e.g., space antennas) and laser mirrors.

Camarda, C. J.; Basiulis, A.

1983-01-01

459

Radiant heating tests of several liquid metal heat-pipe sandwich panels  

NASA Technical Reports Server (NTRS)

Integral heat pipe sandwich panels, which synergistically combine the thermal efficiency of heat pipes and the structural efficiency of honeycomb sandwich construction, were conceived as a means of alleviating thermal stress problems in the Langley Scramjet Engine. Test panels which utilized two different wickable honeycomb cores, facesheets with screen mesh sintered to the internal surfaces, and a liquid metal working fluid (either sodium or potassium) were tested by radiant heating at various heat load levels. The heat pipe panels reduced maximum temperature differences by 31 percent with sodium working fluid and 45 percent with potassium working fluid. Results indicate that a heat pipe sandwich panel is a potential, simple solution to the engine thermal stress problem. Other interesting applications of the concept include: cold plates for electronic component and circuit card cooling, radiators for large space platforms, low distortion large area structures (e.g., space antennas) and laser mirrors.

Camarda, C. J.; Basiulis, A.

1983-01-01

460

Heat pipes in space and on earth  

NASA Technical Reports Server (NTRS)

The performance of heat pipes used in the thermal control system of spacecraft such as OAO-III and ATS-6 is discussed, and applications of heat pipes to permafrost stabilization on the Alaska Pipeline and to heat recovery systems are described. Particular attention is given to the ATS-6, launched in 1974, which employs 55 heat pipes to carry solar and internal power loads to radiator surfaces. In addition, experiments involving radiative cooling based on cryogenic heat pipes have been planned for the Long Duration Exposure Facility spacecraft and for Spacelab. The role of heat pipes in Space Shuttle heat rejection services is also mentioned.

Ollendorf, S.

1978-01-01

461

Arterial and grooved cryogenic heat pipes.  

NASA Technical Reports Server (NTRS)

Tests were conducted on two cryogenic heat pipes using nitrogen as the working fluid. Both pipes are 1.27 cm in diameter. The first pipe is 141 cm long and uses longitudinal grooves in the aluminum wall as the wick structure. The second pipe is 91 cm long and has an arterial wick adjacent to the wall. In addition, circumferential screw threads are machined along the entire length of the inside pipe wall. Both heat pipes primed with no difficulty in the horizontal position. Start-up after burn-out was obtained repeatedly. However, more testing is required to determine whether the artery pipe is as reliable as the grooved pipe with respect to priming. Once primed, the artery heat pipe is much less sensitive to elevation than the grooved design and, consequently, offers a significant advantage with respect to ground testing. Heat-transfer characteristics of the two pipes were comparable, with both pipes achieving the initial goal of 1000 watt-cm of heat-transport capability.

Brennan, P.; Trimmer, D.; Sherman, A.; Cygnarowicz, T.

1971-01-01

462

Integrity of steel pipe during reeling  

SciTech Connect

An assessment of defect significance, with respect to fracture and plastic collapse, in parent pipe and girth welds in seamless 16in OD x 25mm WT pipe to API 5L X52 is described. Fracture mechanics (CTOD) resistance curve tests were conducted on parent pipe, cellulosic girth weld metal and HAZ. BSI PD6493 Level 3 analyses were conducted to assess the significance of potential flaws when the pipe is subjected to plastic strains of up to 2.4%, as experienced during the pipe reeling process (i.e. reeling and unreeling). The safety in the predicted flaw sizes was assessed against full scale bend tests on pipe containing artificial flaws and subjected to simulated pipe reeling. Despite the high strains involved, the predicted flaw sizes to avoid failure were conservative but realistic. It is shown that during service (when longitudinal stresses of up to 72% SMYS may be applied) flaws of the maximum predicted size will remain stable.

Pisarski, H.G.; Phaal, R.; Hadley, I. [TWI, Cambridge (United Kingdom). Dept. of Engineering; Francis, R. [Stena Offshore Ltd., Aberdeen (United Kingdom)

1994-12-31

463

Through Weld Inspection of Wrought Stainless Steel Piping Using Phased Arrays  

SciTech Connect

Outline: Discuss far-side weld problem and phased array techniques applied. Describe laboratory work on flawed piping specimens using L- and S-wave arrays and provide synopsis of results. Discuss conclusions ofr capability of phased array as applied to austenitic welds. Research Approach: Evaluate phased arrays on unifornly-welded piping specimens. Apply best methods to non-uniform welds. Correlate acoustic responses as function of weld microstructures.

Anderson, Michael T.; Cumblidge, Stephen E.; Doctor, Steven R.

2004-12-31

464

Development of a curved pipe capability for the NASTRAN finite element program  

NASA Technical Reports Server (NTRS)

A curved pipe element capability for the NASTRAN structural analysis program is developed using the NASTRAN dummy element feature. A description is given of the theory involved in the subroutines which describe stiffness, mass, thermal and enforced deformation loads, and force and stress recovery for the curved pipe element. Incorporation of these subroutines into NASTRAN is discussed. Test problems are proposed. Instructions on use of the new element capability are provided.

Jeter, J. W., Jr.

1977-01-01

465

Investigation of loads generated by temperature transients in pipes  

NASA Astrophysics Data System (ADS)

The effect of a transient temperature on the stress distribution due to a fluid flowing through a pipe is analytically determined using the definition of a variable called in this paper shifted time. This variable, which is related to the axial coordinate, the average fluid velocity and the real time, is defined to make the transient thermal problem one-dimensional. The stresses are then calculated from the temperature solution using the linear theory of viscoelasticity.

Maneschy, C. E.

1988-12-01

466

Heat pumps and heat pipes for applications in cold regions  

Microsoft Academic Search

Advanced active carbon fibre\\/NH3 heat pumps with dual sources of energy (solar\\/gas) were developed for providing space heating, cooling and sanitary hot water\\u000a for buildings. The next heat pump generation will include a combination of chemicals with an active carbon fibre to increase\\u000a the NH3 absorption. Combination of heat pipes and heat pumps solves the problem of heating the ground

Leonard L. Vasiliev

1999-01-01

467

ICSBEP Benchmarks For Nuclear Data Applications  

NASA Astrophysics Data System (ADS)

The International Criticality Safety Benchmark Evaluation Project (ICSBEP) was initiated in 1992 by the United States Department of Energy. The ICSBEP became an official activity of the Organization for Economic Cooperation and Development (OECD) — Nuclear Energy Agency (NEA) in 1995. Representatives from the United States, United Kingdom, France, Japan, the Russian Federation, Hungary, Republic of Korea, Slovenia, Serbia and Montenegro (formerly Yugoslavia), Kazakhstan, Spain, Israel, Brazil, Poland, and the Czech Republic are now participating. South Africa, India, China, and Germany are considering participation. The purpose of the ICSBEP is to identify, evaluate, verify, and formally document a comprehensive and internationally peer-reviewed set of criticality safety benchmark data. The work of the ICSBEP is published as an OECD handbook entitled "International Handbook of Evaluated Criticality Safety Benchmark Experiments." The 2004 Edition of the Handbook contains benchmark specifications for 3331 critical or subcritical configurations that are intended for use in validation efforts and for testing basic nuclear data. New to the 2004 Edition of the Handbook is a draft criticality alarm / shielding type benchmark that should be finalized in 2005 along with two other similar benchmarks. The Handbook is being used extensively for nuclear data testing and is expected to be a valuable resource for code and data validation and improvement efforts for decades to come. Specific benchmarks that are useful for testing structural materials such as iron, chromium, nickel, and manganese; beryllium; lead; thorium; and 238U are highlighted.

Briggs, J. Blair

2005-05-01

468

Benchmark Gamma Spectroscopy Measurements of Uranium Hexafluoride in Aluminmum Pipe with a Sodium Iodide Detector  

Microsoft Academic Search

The expected increased demand in fuel for nuclear power plants, combined with the fact that a significant portion of the current supply from the blend down of weapons-source material will soon be coming to an end, has led to the need for new sources of enriched uranium for nuclear fuel. As a result, a number of countries have announced plans,

Jose A March-Leuba; Taner Uckan; John E Gunning; Patrick D Brukiewa; Belle R Upadhyaya; Stephen M Revis

2010-01-01

469

Developing integrated benchmarks for DOE performance measurement  

SciTech Connect

The objectives of this task were to describe and evaluate selected existing sources of information on occupational safety and health with emphasis on hazard and exposure assessment, abatement, training, reporting, and control identifying for exposure and outcome in preparation for developing DOE performance benchmarks. Existing resources and methodologies were assessed for their potential use as practical performance benchmarks. Strengths and limitations of current data resources were identified. Guidelines were outlined for developing new or improved performance factors, which then could become the basis for selecting performance benchmarks. Data bases for non-DOE comparison populations were identified so that DOE performance could be assessed relative to non-DOE occupational and industrial groups. Systems approaches were described which can be used to link hazards and exposure, event occurrence, and adverse outcome factors, as needed to generate valid, reliable, and predictive performance benchmarks. Data bases were identified which contain information relevant to one or more performance assessment categories . A list of 72 potential performance benchmarks was prepared to illustrate the kinds of information that can be produced through a benchmark development program. Current information resources which may be used to develop potential performance benchmarks are limited. There is need to develop an occupational safety and health information and data system in DOE, which is capable of incorporating demonstrated and documented performance benchmarks prior to, or concurrent with the development of hardware and software. A key to the success of this systems approach is rigorous development and demonstration of performance benchmark equivalents to users of such data before system hardware and software commitments are institutionalized.

Barancik, J.I.; Kramer, C.F.; Thode, Jr. H.C.

1992-09-30

470

Visual alignment technology for seamless steel pipe linearity measurement  

NASA Astrophysics Data System (ADS)

Linearity measurement is the key problem in seamless steel pipe industry. For the modern industry of seamless steel pipe production, the traditional method cannot meet the needs of on-line and real-time measurement performance. Recently, visual inspection has developed rapidly and has the advantages of high speed, high precision, non-contact, automation and high manoeuvrability. So a novel approach to on-line and real-time linearity measurement of seamless steel pipe based on visual alignment technology is presented in this paper. Firstly the theory of visual alignment measuring is introduced. And then an on-line and real-time linearity measuring system, which consists of multistructured light sensor for seamless steel pipe factory of Tianjin, is invented with the technology of visual alignment. And key technologies for a visual alignment, such as the optimum design of high precision light-structured sensor, coordinates integration of multisensor, the mathematical model of visual measurement, and algorithm for ellipse center computations with high precision are studied in detail. Measurement results show that the measuring system is reasonable and can measure not only the linearity but also the coaxiality of large-scale parts.

Wu, Bin; Xue, Ting; Zhu, Jigui; Ye, Shenghua

2006-06-01

471

Ultrasonic multi-skip tomography for pipe inspection  

SciTech Connect

The inspection of wall loss corrosion is difficult at pipe supports due to limited accessibility. The recently developed ultrasonic Multi-Skip screening technique is suitable for this problem. The method employs ultrasonic transducers in a pitch-catch geometry positioned on opposite sides of the pipe support. Shear waves are transmitted in the axial direction within the pipe wall, reflecting multiple times between the inner and outer surfaces before reaching the receivers. Along this path, the signals accumulate information on the integral wall thickness (e.g., via variations in travel time). The method is very sensitive in detecting the presence of wall loss, but it is difficult to quantify both the extent and depth of the loss. Multi-skip tomography has been developed to reconstruct the wall thickness profile along the axial direction of the pipe. The method uses model-based full wave field inversion; this consists of a forward model for predicting the measured wave field and an iterative process that compares the predicted and measured wave fields and minimizes the differences with respect to the model parameters (i.e., the wall thickness profile). Experimental results are very encouraging. Various defects (slot and flat bottom hole) are reconstructed using the tomographic inversion. The general shape and width are well recovered. The current sizing accuracy is in the order of 1 mm.

Volker, Arno; Zon, Tim van [TNO, Stieltjesweg 1, P.O. Box 155 2600 AD Delft (Netherlands)

2014-02-18

472

Ultrasonic pipe inspection prove-ups can be improved  

SciTech Connect

In extensive tests conducted in its laboratories, Lone Star Steel found conventional manual ultrasonic prove-ups of pipe imperfections to be consistently inaccurate. Error rates ranged from 65% to 100%. On an average, the author found that of every five joints of casing rejected by manual prove-ups, four did not have rejectable imperfections. In many cases, the rejected pipe cost several thousand dollars a joint. The cost of rejecting acceptable pipe is not one pipe manufacturer can simply absorb. Buyers eventually pay the cost by paying higher overall prices. Yet, this research shows unnecessary rejection is a cost that can be easily eliminated by making simple changes in conventional ultrasonic prove-up procedures. The proposed changes do not involve loosening existing standards. But the author are convinced that it is to the oil and gas industry's best interests to ensure prove-up procedures produce accurate and repeatable results. The paper describes current inspection practices, indications of problems, the variable calibration notch, the variable wedge, the wrong transducer, the advantage of one-half inch transducers, surface preparation, common misconceptions, and recommendations.

Hodges, B.J. (Lone Star Steel, Lone Star, TX (United States))

1993-09-13

473

System for Testing Thermal Insulation of Pipes  

NASA Technical Reports Server (NTRS)

An apparatus and method have been developed for measuring the rates of leakage of heat into pipes carrying liquids, the purpose of the measurements being to quantify the thermal performance of the insulation system. The apparatus is designed primarily for testing pipes used to carry cryogenic liquids, but can also be used for measuring the thermal performance of other insulated pipes or piping systems. The basic measurement principle is straightforward: The outer surface of the pipe insulation is maintained at a fixed warmer temperature. The interior of the pipe is maintained in a narrow fixed lower-temperature range by means of a regular liquid (e.g., water) that is pumped through the pipe at a known flow rate or a cryogenic liquid (e.g., nitrogen) that is saturated at atmospheric pressure and replenished until steady-state conditions are achieved. In the case of water or another liquid pumped through, the inlet and outlet temperatures are measured and heat-leak power is calculated as the mass flow rate of the liquid multiplied by the specific heat of the liquid multiplied by the inlet-to-outlet temperature rise of the liquid. In the case of liquid nitrogen or another low-temperature boiling liquid, the heat-leak power is calculated as the rate of boil-off multiplied by the latent heat of vaporization of the liquid. Then the thermal-insulation performance of the pipe system can be calculated as a function of the measured heat-leak power, the inner and outer boundary temperatures, and the dimensions of the pipe. The apparatus can test as many as three pipes simultaneously. The pipes can have inner diameters up to .15 cm and outer diameters up to .20 cm. The lengths of the pipes may vary; typical lengths are of the order of 18 m. Two thermal guard boxes . one for each end of the pipe(s) under test . are used to make the inlet and outlet fluid connections to the pipe(s) (see figure). The connections include bellows that accommodate thermal expansion and contraction of the pipes. The guard boxes and pipe(s) are positioned so that the pipe(s) slope upward from the upstream to the downstream end at an angle of at least 2 . The upward slope allows vapor bubbles to accumulate at the downstream end. The thermal guard boxes keep the ends of the pipes at the lower interior temperature to prevent spurious lengthwise leakage of heat into the pipes. It is important to prevent this spurious heat leakage because, if it were allowed to occur, it could contribute a large error in the measured heat-leak power. The upstream thermal guard box includes a heat exchanger through which liquid flowing into the pipe(s) is subcooled to the saturation temperature corresponding to the ambient pressure. Conversely, this heat exchanger can also be used to warm the flowing liquid to a desired fixed temperature. The apparatus includes a temperature control device that is placed around each pipe under test. Each device is operated under thermostatic control to maintain the outer surface of the pipe insulation at the specified test temperature. All measurements are recorded on a portable data-acquisition system.

Fesmire, James E.; Augustynowicz, Stanislaw D.; Nagy, Zoltan F.

2003-01-01

474

Drinking Water Problems: Corrosion  

E-print Network

Drinking Water Problems: Corrosion Mark L. McFarland, Tony L. Provin, and Diane E. Boellstorff and fail. Corrosion can cause three types of damage: · The entire metal surface gradually thins and red (Fig. 1). · Deep pits appear that can penetrate pipe or tank walls. This type of corrosion may not add

475

Dual manifold heat pipe evaporator  

DOEpatents

An improved evaporator section is described for a dual manifold heat pipe. Both the upper and lower manifolds can have surfaces exposed to the heat source which evaporate the working fluid. The tubes in the tube bank between the manifolds have openings in their lower extensions into the lower manifold to provide for the transport of evaporated working fluid from the lower manifold into the tubes and from there on into the upper manifold and on to the condenser portion of the heat pipe. A wick structure lining the inner walls of the evaporator tubes extends into both the upper and lower manifolds. At least some of the tubes also have overflow tubes contained within them to carry condensed working fluid from the upper manifold to pass to the lower without spilling down the inside walls of the tubes. 1 figure.

Adkins, D.R.; Rawlinson, K.S.

1994-01-04

476

Axially grooved heat pipes - 1976  

NASA Technical Reports Server (NTRS)

This paper summarizes the 'state-of-the-art' of axially grooved heat pipes. Applications are identified and the related heat pipe design and performance are defined. Recent developments in the analysis, design and fabrication of axially grooved hardware are also discussed. A mathematical model which predicts the hydrodynamic behavior and accounts for liquid recession, liquid/vapor shear interaction and 1-g puddle flow is also presented. Performance data for various fluids in the 100-500 K range is compared to predictions from the Groove Analysis Program (GAP). Finally, a simplified closed form solution which accounts for gravity effects, self-priming and composite pumping by the grooves as well as all of the hydrodynamic losses is also discussed.

Brennan, P. J.; Kroliczek, E. J.; Jen, H.; Mcintosh, R.

1977-01-01

477

Metrics and Benchmarks for Visualization  

NASA Technical Reports Server (NTRS)

What is a "good" visualization? How can the quality of a visualization be measured? How can one tell whether one visualization is "better" than another? I claim that the true quality of a visualization can only be measured in the context of a particular purpose. The same image generated from the same data may be excellent for one purpose and abysmal for another. A good measure of visualization quality will correspond to the performance of users in accomplishing the intended purpose, so the "gold standard" is user testing. As a user of visualization software (or at least a consultant to such users) I don't expect visualization software to have been tested in this way for every possible use. In fact, scientific visualization (as distinct from more "production oriented" uses of visualization) will continually encounter new data, new questions and new purposes; user testing can never keep up. User need software they can trust, and advice on appropriate visualizations of particular purposes. Considering the following four processes, and their impact on visualization trustworthiness, reveals important work needed to create worthwhile metrics and benchmarks for visualization. These four processes are (1) complete system testing (user-in-loop), (2) software testing, (3) software design and (4) information dissemination. Additional information is contained in the original extended abstract.

Uselton, Samuel P.; Lasinski, T. A. (Technical Monitor)

1995-01-01

478

XBX: eXternal Benchmarking eXtension for the SUPERCOP Crypto Benchmarking Framework  

Microsoft Academic Search

\\u000a SUPERCOP [1] is a benchmarking framework for cryptographic algorithms like ciphers and hash functions. It automatically benchmarks\\u000a algorithms across several implementations, compilers, compiler options and input data lengths. Since it is freely available\\u000a for download the results are easily reproducible and benchmark results for virtually every computer that is capable of running\\u000a SUPERCOP are available. However, since SUPERCOP is a

Christian Wenzel-Benner; Jens Gräf

2010-01-01

479

The FLUKA Code: Description And Benchmarking  

SciTech Connect

The physics model implemented inside the FLUKA code are briefly described, with emphasis on hadronic interactions. Examples of the capabilities of the code are presented including basic (thin target) and complex benchmarks.

Battistoni, Giuseppe; Muraro, S.; Sala, Paola R.; /INFN, Milan; Cerutti, Fabio; Ferrari, A.; Roesler, Stefan; /CERN; Fasso, A.; /SLAC; Ranft, J.; /Siegen U.

2007-09-18

480

The FLUKA code: description and benchmarking  

SciTech Connect

The physics model implemented inside the FLUKA code are briefly described, with emphasis on hadronic interactions. Examples of the capabilities of the code are presented including basic (thin target) and complex benchmarks.

Battistoni, G.; Muraro, S.; Sala, P. R. [INFN sezione di Milano, via Celoria 16, I-20133 Milan (Italy); Cerutti, F.; Ferrari, A.; Roesler, S. [CERN, CH-1211 GENEVE 23 (Switzerland); Fasso, A. [SLAC, Stanford (United States); Ranft, J. [Siegen University (Germany)

2007-03-19

481

Benchmarking Sustainability: the use of Indicators  

E-print Network

Benchmarking Sustainability: the use of Indicators Introduction The concept of sustainable development is both very popular and elusive. The overwhelming appeal of sustainability is situated to build a generally shared perception of sustainable development (Butler, 1998). For many people

Zaferatos, Nicholas C.

482

Toward Scalable Benchmarks for Mass Storage Systems  

NASA Technical Reports Server (NTRS)

This paper presents guidelines for the design of a mass storage system benchmark suite, along with preliminary suggestions for programs to be included. The benchmarks will measure both peak and sustained performance of the system as well as predicting both short- and long-term behavior. These benchmarks should be both portable and scalable so they may be used on storage systems from tens of gigabytes to petabytes or more. By developing a standard set of benchmarks that reflect real user workload, we hope to encourage system designers and users to publish performance figures that can be compared with those of other systems. This will allow users to choose the system that best meets their needs and give designers a tool with which they can measure the performance effects of improvements to their systems.

Miller, Ethan L.

1996-01-01

483

Benchmarking ENDF/B-VII.0  

NASA Astrophysics Data System (ADS)

The new major release VII.0 of the ENDF/B nuclear data library has been tested extensively using benchmark calculations. These were based upon MCNP-4C3 continuous-energy Monte Carlo neutronics simulations, together with nuclear data processed using the code NJOY. Three types of benchmarks were used, viz., criticality safety benchmarks, (fusion) shielding benchmarks, and reference systems for which the effective delayed neutron fraction is reported. For criticality safety, more than 700 benchmarks from the International Handbook of Criticality Safety Benchmark Experiments were used. Benchmarks from all categories were used, ranging from low-enriched uranium, compound fuel, thermal spectrum ones (LEU-COMP-THERM), to mixed uranium-plutonium, metallic fuel, fast spectrum ones (MIX-MET-FAST). For fusion shielding many benchmarks were based on IAEA specifications for the Oktavian experiments (for Al, Co, Cr, Cu, LiF, Mn, Mo, Si, Ti, W, Zr), Fusion Neutronics Source in Japan (for Be, C, N, O, Fe, Pb), and Pulsed Sphere experiments at Lawrence Livermore National Laboratory (for 6Li, 7Li, Be, C, N, O, Mg, Al, Ti, Fe, Pb, D 2O, H 2O, concrete, polyethylene and teflon). For testing delayed neutron data more than thirty measurements in widely varying systems were used. Among these were measurements in the Tank Critical Assembly (TCA in Japan) and IPEN/MB-01 (Brazil), both with a thermal spectrum, and two cores in Masurca (France) and three cores in the Fast Critical Assembly (FCA, Japan), all with fast spectra. In criticality safety, many benchmarks were chosen from the category with a thermal spectrum, low-enriched uranium, compound fuel (LEU-COMP-THERM), because this is typical of most current-day reactors, and because these benchmarks were previously underpredicted by as much as 0.5% by most nuclear data libraries (such as ENDF/B-VI.8, JEFF-3.0). The calculated results presented here show that this underprediction is no longer there for ENDF/B-VII.0. The average over 257 benchmarks deviates only 0.017% from the measured benchmark value. Moreover, no clear trends (with e.g. enrichment, lattice pitch, or spectrum) have been observed. Also for fast spectrum benchmarks, both for intermediately or highly enriched uranium and for plutonium, clear improvements are apparent from the calculations. The results for bare assemblies have improved, as well as those with a depleted or natural uranium reflector. On the other hand, the results for plutonium solutions (PU-SOL-THERM) are still high, on average (over 120 benchmarks) roughly 0.6%. Furthermore there still is a bias for a range of benchmarks based on cores in the Zero Power Reactor (ANL) with sizable amounts of tungsten in them. The results for the fusion shielding benchmarks have not changed significantly, compared to ENDF/B-VI.8, for most materials. The delayed neutron testing shows that the values for both thermal and fast spectrum cases are now well predicted, which is an improvement when compared with ENDF/B-VI.8.

van der Marck, Steven C.

2006-12-01

484

Benchmark testing and independent verification of the VS2DT computer code  

SciTech Connect

The finite difference flow and transport simulator VS2DT was benchmark tested against several other codes which solve the same equations (Richards equation for flow and the Advection-Dispersion equation for transport). The benchmark problems investigated transient two-dimensional flow in a heterogeneous soil profile with a localized water source at the ground surface. The VS2DT code performed as well as or better than all other codes when considering mass balance characteristics and computational speed. It was also rated highly relative to the other codes with regard to ease-of-use. Following the benchmark study, the code was verified against two analytical solutions, one for two-dimensional flow and one for two-dimensional transport. These independent verifications show reasonable agreement with the analytical solutions, and complement the one-dimensional verification problems published in the code`s original documentation.

McCord, J.T. [Sandia National Labs., Albuquerque, NM (United States). Environmental Risk Assessment and Risk Management Dept.; Goodrich, M.T. [IT Corp., Albuquerque, NM (United States)

1994-11-01

485

Verification of the shift Monte Carlo code with the C5G7 reactor benchmark  

SciTech Connect

Shift is a new hybrid Monte Carlo/deterministic radiation transport code being developed at Oak Ridge National Laboratory. At its current stage of development, Shift includes a parallel Monte Carlo capability for simulating eigenvalue and fixed-source multigroup transport problems. This paper focuses on recent efforts to verify Shift's Monte Carlo component using the two-dimensional and three-dimensional C5G7 NEA benchmark problems. Comparisons were made between the benchmark eigenvalues and those output by the Shift code. In addition, mesh-based scalar flux tally results generated by Shift were compared to those obtained using MCNP5 on an identical model and tally grid. The Shift-generated eigenvalues were within three standard deviations of the benchmark and MCNP5-1.60 values in all cases. The flux tallies generated by Shift were found to be in very good agreement with those from MCNP. (authors)

Sly, N. C.; Mervin, B. T. [Dept. of Nuclear Engineering, Univ. of Tennessee, 311 Pasqua Engineering Building, Knoxville, TN 37996-2300 (United States); Mosher, S. W.; Evans, T. M.; Wagner, J. C. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831 (United States); Maldonado, G. I. [Dept. of Nuclear Engineering, Univ. of Tennessee, 311 Pasqua Engineering Building, Knoxville, TN 37996-2300 (United States)

2012-07-01

486

TR0607-1 June 2007 Benchmark Problem 1 Specification  

E-print Network

Treatment and Aortic Stenosis with Transient Ischemic Attacks), in both natural English and in the CIG with breast cancer. Actions: Admit Patient (n1), Surgery and radiotherapy Treatment (n2), Adjuvant Therapy (n3SurgeryTreatRN), (content, [(admitPatient(P,O),n1,[inPatient(P,O)]), (surgeryTreatment(P,Breast),n2,[results

Winstanley, Graham

487

Simple Benchmark Specifications for Space Radiation Protection  

NASA Technical Reports Server (NTRS)

This report defines space radiation benchmark specifications. This specification starts with simple, monoenergetic, mono-directional particles on slabs and progresses to human models in spacecraft. This report specifies the models and sources needed to what the team performing the benchmark needs to produce in a report. Also included are brief descriptions of how OLTARIS, the NASA Langley website for space radiation analysis, performs its analysis.

Singleterry, Robert C. Jr.; Aghara, Sukesh K.

2013-01-01

488

Postmark: a new file system benchmark  

Microsoft Academic Search

Existing file system benchmarks are deficient in portraying performance in the ephemeral small-file regime used by Internet software, especially: electronicmail; netnews; and web-based commerce. PostMark is a new benchmark to measure performance for this class of application.In this paper, PostMark test results are presented and analyzed for both UNIX and Windows NT application servers. Network Appliance Filers (file server appliances)

J. Katcher

1997-01-01

489

1Dimensional Parallel FFT Benchmark on SUPRENUM  

Microsoft Academic Search

. A distributed memory vectorised 1-dimensional FFT benchmarkis first presented. The performance results of this benchmark on SUPRENUMare given and discussed. A performance analysis of the distributed memoryFFT benchmark is performed and Hockney's performance parameters (r1and n 1=2 ) are then employed to derive the performance formula. This formulais shown to fit the experimental results very well. A generalization of

Vladimir Getov

1992-01-01

490

The NAS Parallel Benchmarks in Titanium  

Microsoft Academic Search

Titanium is an explicitly parallel dialect of JavaTM designed for high-performance scientific programming. It offers object-orientation, strong typing, and safe memory management in the context of a language that supports high performance and scal- able parallelism. We present an overview of the language features and demonstrate their use in the context of the NAS Parallel Benchmarks, a benchmark suite of

Kaushik Datta

2006-01-01

491

Implementation of NAS Parallel Benchmarks in Java  

NASA Technical Reports Server (NTRS)

A number of features make Java an attractive but a debatable choice for High Performance Computing (HPC). In order to gauge the applicability of Java to the Computational Fluid Dynamics (CFD) we have implemented NAS Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would move Java closer to Fortran in the competition for CFD applications.

Frumkin, Michael; Schultz, Matthew; Jin, Hao-Qiang; Yan, Jerry

2000-01-01

492

A framework for benchmarking land models  

NASA Astrophysics Data System (ADS)

Land models, which have been developed by the modeling community in the past few decades to predict future states of ecosystems and climate, have to be critically evaluated for their performance skills of simulating ecosystem responses and feedback to climate change. Benchmarking is an emerging procedure to measure performance of models against a set of defined standards. This paper proposes a benchmarking framework for evaluation of land model performances and, meanwhile, highlights major challenges at this infant stage of benchmark analysis. The framework includes (1) targeted aspects of model performance to be evaluated, (2) a set of benchmarks as defined references to test model performance, (3) metrics to measure and compare performance skills among models so as to identify model strengths and deficiencies, and (4) model improvement. Land models are required to simulate exchange of water, energy, carbon and sometimes other trace gases between the atmosphere and land surface, and should be evaluated for their simulations of biophysical processes, biogeochemical cycles, and vegetation dynamics in response to climate change across broad temporal and spatial scales. Thus, one major challenge is to select and define a limited number of benchmarks to effectively evaluate land model performance. The second challenge is to develop metrics of measuring mismatches between models and benchmarks. The metrics may include (1) a priori thresholds of acceptable model performance and (2) a scoring system to combine data-model mismatches for various processes at different temporal and spatial scales. The benchmark analyses should identify clues of weak model performance to guide future development, thus enabling improved predictions of future states of ecosystems and climate. The near-future research effort should be on development of a set of widely acceptable benchmarks that can be used to objectively, effectively, and reliably evaluate fundamental properties of land models to improve their prediction performance skills.

Luo, Y. Q.; Randerson, J. T.; Abramowitz, G.; Bacour, C.; Blyth, E.; Carvalhais, N.; Ciais, P.; Dalmonech, D.; Fisher, J. B.; Fisher, R.; Friedlingstein, P.; Hibbard, K.; Hoffman, F.; Huntzinger, D.; Jones, C. D.; Koven, C.; Lawrence, D.; Li, D. J.; Mahecha, M.; Niu, S. L.; Norby, R.; Piao, S. L.; Qi, X.; Peylin, P.; Prentice, I. C.; Riley, W.; Reichstein, M.; Schwalm, C.; Wang, Y. P.; Xia, J. Y.; Zaehle, S.; Zhou, X. H.

2012-10-01

493

A framework for benchmarking land models  

SciTech Connect

Land models, which have been developed by the modeling community in the past few decades to predict future states of ecosystems and climate, have to be critically evaluated for their performance skills of simulating ecosystem responses and feedback to climate change. Benchmarking is an emerging procedure to measure performance of models against a set of defined standards. This paper proposes a benchmarking framework for evaluation of land model performances and, meanwhile, highlights major challenges at this infant stage of benchmark analysis. The framework includes (1) targeted aspects of model performance to be evaluated, (2) a set of benchmarks as defined references to test model performance, (3) metrics to measure and compare performance skills among models so as to identify model strengths and deficiencies, and (4) model improvement. Land models are required to simulate exchange of water, energy, carbon and sometimes other trace gases between the atmosphere and land surface, and should be evaluated for their simulations of biophysical processes, biogeochemical cycles, and vegetation dynamics in response to climate change across broad temporal and spatial scales. Thus, one major challenge is to select and define a limited number of benchmarks to effectively evaluate land model performance. The second challenge is to develop metrics of measuring mismatches between models and benchmarks. The metrics may include (1) a priori thresholds of acceptable model performance and (2) a scoring system to combine data–model mismatches for various processes at different temporal and spatial scales. The benchmark analyses should identify clues of weak model performance to guide future development, thus enabling improved predictions of future states of ecosystems and climate. The near-future research effort should be on development of a set of widely acceptable benchmarks that can be used to objectively, effectively, and reliably evaluate fundamental properties of land models to improve their prediction performance skills.

Luo, Yiqi; Randerson, J.; Abramowitz, G.; Bacour, C.; Blyth, E.; Carvalhais, N.; Ciais, Philippe; Dalmonech, D.; Fisher, J.B.; Fisher, R.; Friedlingstein, P.; Hibbard, Kathleen A.; Hoffman, F. M.; Huntzinger, Deborah; Jones, C.; Koven, C.; Lawrence, David M.; Li, D.J.; Mahecha, M.; Niu, S.L.; Norby, Richard J.; Piao, S.L.; Qi, X.; Peylin, P.; Prentice, I.C.; Riley, William; Reichstein, M.; Schwalm, C.; Wang, Y.; Xia, J. Y.; Zaehle, S.; Zhou, X. H.

2012-10-09

494

Combinational profiles of sequential benchmark circuits  

Microsoft Academic Search

A set of 31 digital sequential circuits described at the gate level is presented. These circuits extend the size and complexity of the ISCAS'85 set of combinational circuits and can serve as benchmarks for researchers interested in sequential test generation, scan-based test generation, and mixed sequential\\/scan-based test generation using partial scan techniques. Although all the benchmark circuits are sequential, synchronous,

Franc Brglez; David Bryan; K. Kozminski

1989-01-01

495

Rat's Life: A Cognitive Robotics Benchmark  

Microsoft Academic Search

This paper describes Rat’s Life: a complete cognitive robotics benchmark that was carefully designed to be easily reproducible\\u000a in a research lab with limited resources. It relies on two e-puck robots, some LEGO bricks and the Webots robot simulation\\u000a software. This benchmark is a survival game where two robots compete against each other for resources in an unknown maze.\\u000a Like

Olivier Michel; Fabien Rohrer; Yvan Bourquin

2008-01-01

496

ITER RWM benchmarking VALEN modeling results  

E-print Network

[m] out Zvv[m] Zsep(m) coils Z[m] sensor Z[m] Z[m] R [m] ITER.RWM.comparison Benchmarking model continuous, walls, control coils, blanket modules, & Bp sensors Z[m] R[m] ITER.RWM.comparison #12;10-1 100 101 102;-6 -4 -2 0 2 4 6 0 2 4 6 8 10 12 ITER RWM benchmarking plasma, walls, control coils, & Bp sensor in Zvv

497

CommBench-a telecommunications benchmark for network processors  

Microsoft Academic Search

The paper presents a benchmark, CommBench, for use in evaluating and designing telecommunications network processors. The benchmark applications focus on small, computationally intense program kernels typical of the network processor environment. The benchmark is composed of eight programs, four of them oriented towards packet header processing and four oriented towards data stream processing. The benchmark is defined and characteristics such

Tilman Wolf; Mark Franklin

2000-01-01

498

A Set of Benchmarks fo Modular Testing of SOCs  

Microsoft Academic Search

Abstract: This paper presents the ITC'02 SOC Test Benchmarks. The purpose of this new benchmark set is to stimulate research into newmethods and tools for modular testing of SOCs and to enable the objective comparison of such methods and tools with respect toeffectiveness and efficiency. The paper defines the benchmark format and naming scheme, and presents the benchmark SOCs. Inaddition,

Erik Jan Marinissen; Vikram Iyengar; Krishnendu Chakrabarty

2002-01-01

499

TITLE: The NAS Parallel Benchmarks AUTHOR: David H Bailey1  

E-print Network

TITLE: The NAS Parallel Benchmarks AUTHOR: David H Bailey1 ACRONYMS: NAS, NPB DEFINITION: The NAS Parallel Benchmarks (NPB) are a suite of parallel computer per- formance benchmarks. They were originally. Venkatakrishnan and Sisira Weeratunga. DISCUSSION: The original NAS Parallel Benchmarks consisted of eight

Bailey, David H.

500

Towards a Benchmark for Model Checkers of Asynchronous Concurrent Systems  

E-print Network

parallel model checkers. Pel´anek [38] also recog- nises the need for benchmarking and suggestsTowards a Benchmark for Model Checkers of Asynchronous Concurrent Systems Diyaa­Addein Atiya, N,catano,luettgen}@cs.york.ac.uk Abstract. Benchmarks, such as the established ISCAS benchmarks of digital circuits, have been successfully