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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 for the General Electric Advanced Boiling Water Reactor  

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 an advanced boiling water reactor standard design, 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 advanced reactor standard design. It will be required that the combined license holders demonstrate that their solutions to these problems are in agreement with the benchmark problem set.

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

1993-08-01

4

Compilation of Piping Benchmark Problems - Cooperative International Effort.  

National Technical Information Service (NTIS)

This report is the culmination of an effort initiated in 1976 by the IWGFR to evaluate detailed and simplified analysis methods for piping systems with particular emphasis on piping bends. The procedure was to collect from participating member IWGFR count...

W. J. McAfee

1979-01-01

5

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

6

Eddy Current Benchmark Problem  

NASA Astrophysics Data System (ADS)

This paper describes the proposal of a benchmark activity. The objective of the proposed eddy current benchmark problem is to evaluate accuracy of various numerical or semi-analytical methods in predicting an eddy current probe multi-frequency response. The probe has a complicated structure and it consists of a cylindrical ferrite core with five symmetrically placed columns. The probe was used to test plates made from nickel-base superalloy INCONEL 600. In the plate a set of defects were introduced. An AC currents consist of 15 harmonic components are applied to the excitation coils. In all cases the specimens were examined by placing the probe on the reverse side of the flaws. The acquired data will be send by email to all participants of the benchmark's activity.

Chady, T.; Sikora, R.

2008-02-01

7

VHTRC temperature coefficient benchmark problem.  

National Technical Information Service (NTIS)

As an activity of IAEA Coordinated Research Programme, a benchmark problem is proposed for verifications of neutronic calculation codes for a low enriched uranium fuel high temperature gas-cooled reactor. Two problems are given on the base of heating expe...

H. Yasuda T. Yamane T. Sasa

1994-01-01

8

Overview of cooperative international piping benchmark analyses  

SciTech Connect

This paper presents an overview of an effort initiated in 1976 by the International Working Group on Fast Reactors (IWGFR) of the International Atomic Energy Agency (IAEA) to evaluate detailed and simplified inelastic analysis methods for piping systems with particular emphasis on piping bends. The procedure was to collect from participating member IAEA countries descriptions of tests and test results for piping systems or bends (with emphasis on high temperature inelastic tests), to compile, evaluate, and issue a selected number of these problems for analysis, and to compile and make a preliminary evaluation of the analyses results. The Oak Ridge National Laboratory coordinated this activity, including compilation of the original problems and the final analyses results. Of the problem descriptions submitted, three were selected to be used. These were issued in December 1977. As a follow-on activity, addenda were issued that provided additional data or corrections to the original problem statement. A variety of both detailed and simplified analysis solutions was obtained. A brief comparative assessment of the analyses is contained in this paper.

McAfee, W.J.

1983-01-01

9

Overview of cooperative international piping benchmark analyses  

SciTech Connect

This paper presents an overview of an effort initiated in 1976 by the International Working Group on Fast Reactors (IWGFR) of the International Atomic Energy Agency (IAEA) to evaluate detailed and simplified inelastic analysis methods for piping systems with particular emphasis on piping bends. The procedure was to collect from participating member IAEA countries descriptions of tests and test results for piping systems or bends (with emphasis on high temperature inelastic tests), to compile, evaluate, and issue a selected number of these problems for analysis, and to compile and make a preliminary evaluation of the analyses results. Of the problem descriptions submitted three were selected to be used: a 90/sup 0/-elbow at 600/sup 0/C with an in-plane transverse force; a 90/sup 0/-elbow with an in-plane moment; and a 180/sup 0/-elbow at room temperature with a reversed, cyclic, in-plane transverse force. A variety of both detailed and simplified analysis solutions were obtained. A brief comparative assessment of the analyses is contained in this paper. 15 figures.

McAfee, W.J.

1982-01-01

10

Benchmark Problems in Structural Optimization  

Microsoft Academic Search

\\u000a Structural optimization is an important area related to both optimization and structural engineering. Structural optimization\\u000a problems are often used as benchmarks to validate new optimization algorithms or to test the suitability of a chosen algorithm.\\u000a In almost all structural engineering applications, it is very important to find the best possible parameters for given design\\u000a objectives and constraints which are highly

Amir Hossein Gandomi; Xin-She Yang

11

Overview of cooperative international piping benchmark analyses  

Microsoft Academic Search

This paper presents an overview of an effort initiated in 1976 by the International Working Group on Fast Reactors (IWGFR) of the International Atomic Energy Agency (IAEA) to evaluate detailed and simplified inelastic analysis methods for piping systems with particular emphasis on piping bends. The procedure was to collect from participating member IAEA countries descriptions of tests and test results

McAfee

1983-01-01

12

Overview of cooperative international piping benchmark analyses  

Microsoft Academic Search

This paper presents an overview of an effort initiated in 1976 by the International Working Group on Fast Reactors (IWGFR) of the International Atomic Energy Agency (IAEA) to evaluate detailed and simplified inelastic analysis methods for piping systems with particular emphasis on piping bends. The procedure was to collect from participating member IAEA countries descriptions of tests and test results

McAfee

1982-01-01

13

COG validation: SINBAD Benchmark Problems  

SciTech Connect

We validated COG, a 3D Monte Carlo radiation transport code, against experimental data and MNCP4C simulations from the Shielding Integral Benchmark Archive Database (SINBAD) compiled by RSICC. We modeled three experiments: the Osaka Nickel and Aluminum sphere experiments conducted at the OKTAVIAN facility, and the liquid oxygen experiment conducted at the FNS facility. COG results are in good agreement with experimental data and generally within a few % of MCNP results. There are several possible sources of discrepancy between MCNP and COG results: (1) the cross-section database versions are different, MCNP uses ENDFB VI 1.1 while COG uses ENDFB VIR7, (2) the code implementations are different, and (3) the models may differ slightly. We also limited the use of variance reduction methods when running the COG version of the problems.

Lent, E M; Sale, K E; Buck, R M; Descalle, M

2004-02-23

14

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

15

Benchmark Problems for Space Mission Formation Flying  

NASA Technical Reports Server (NTRS)

To provide a high-level focus to distributed space system flight dynamics and control research, several benchmark problems are suggested for space mission formation flying. The problems cover formation flying in low altitude, near-circular Earth orbit, high altitude, highly elliptical Earth orbits, and large amplitude lissajous trajectories about co-linear libration points of the Sun-Earth/Moon system. 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 that are of interest to various agencies.

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

2003-01-01

16

Finite Element Modeling of the World Federation's Second MFL Benchmark Problem  

NASA Astrophysics Data System (ADS)

This paper presents results obtained by simulating the second magnetic flux leakage benchmark problem proposed by the World Federation of NDE Centers. The geometry consists of notches machined on the internal and external surfaces of a rotating steel pipe that is placed between two yokes that are part of a magnetic circuit energized by an electromagnet. The model calculates the radial component of the leaked field at specific positions. The nonlinear material property of the ferromagnetic pipe is taken into account in simulating the problem. The velocity effect caused by the rotation of the pipe is, however, ignored for reasons of simplicity.

Zeng, Zhiwei; Tian, Yong; Udpa, Satish; Udpa, Lalita

2004-02-01

17

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

18

A 3D stylized half-core CANDU benchmark problem  

Microsoft Academic Search

A 3D stylized half-core Canadian deuterium uranium (CANDU) reactor benchmark problem is presented. The benchmark problem is comprised of a heterogeneous lattice of 37-element natural uranium fuel bundles, heavy water moderated, heavy water cooled, with adjuster rods included as reactivity control devices. Furthermore, a 2-group macroscopic cross section library has been developed for the problem to increase the utility of

Justin M. Pounders; Farzad Rahnema; Dumitru Serghiuta; John Tholammakkil

2011-01-01

19

Error Analysis of Variations on Larsen's Benchmark Problem.  

National Technical Information Service (NTIS)

Error norms for three variants of Larsen's benchmark problem are evaluated using three numerical methods for solving the discrete ordinates approximation of the neutron transport equation in multidimensional Cartesian geometry. The three variants of Larse...

Y. Y. Azmy

2001-01-01

20

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

21

Numerical Solutions to the Third CAA Workshop Benchmark Problems  

NASA Technical Reports Server (NTRS)

This paper presents numerical solutions to the problems of propagation of sound waves through a transonic nozzle, shock-sound interactions, and automobile noise involving feedback of the third NASA Computational Aeroacoustics (CAA) Workshop on benchmark problems. The numerical algorithm is based on a dual time scheme for temporal discretization and a third-order finite volume scheme for spatial discretization. The aims of this study are to apply a dual time stepping scheme to treat aeroacoustic problems of sound propagation and to validate our CAA solver with the benchmark problems for developing a numerical tool for noise analysis and control.

Loh, Roy H.; Lin, Wen H.

2000-01-01

22

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

23

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

24

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

25

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

26

A Two Body Benchmark Problem for Transient and Ultrawideband Scattering  

Microsoft Academic Search

In this paper we propose a novel benchmark for numerical solutions of transient and ultrawideband scattering from perfectly conducting targets. The target for the problem comprises two open concentric spherical shells with a common axis of symmetry, which represents the direction of propagation of the incident field. This geometry includes a variety of physical features including surfaces, edges, cavities and

S. M. Booker; S. S. Vinogradov

2002-01-01

27

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

28

Workshops and problems for benchmarking eddy current codes  

SciTech Connect

A series of six workshops was held to compare eddy current codes, using six benchmark problems. The problems include transient and steady-state ac magnetic fields, close and far boundary conditions, magnetic and non-magnetic materials. All the problems are based either on experiments or on geometries that can be solved analytically. The workshops and solutions to the problems are described. Results show that many different methods and formulations give satisfactory solutions, and that in many cases reduced dimensionality or coarse discretization can give acceptable results while reducing the computer time required. 13 refs., 1 tab.

Turner, L.R.; Davey, K.; Ida, N.; Rodger, D.; Kameari, A.; Bossavit, A.; Emson, C.R.I.

1988-02-01

29

MODEL PREDICTION RESULTS FOR 2008 ULTRASONIC BENCHMARK PROBLEMS  

SciTech Connect

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 [School of Mechanical Eng., Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of)

2009-03-03

30

ERW line pipe-1; Installed pipe, especially pre-1970, plagued by problems  

SciTech Connect

Understanding the manufacture and unique problems of electric-resistance welded (ERW) line pipe can aid operators in safely maintaining and using existing ERW pipe and in sharpening key requirements when they specify new ERW materials. Abandoning or replacing large quantities of ERW line pipe is impractical and undesirable. This paper reviews what constitutes ERW pipe, the weaknesses and deficiencies that can occur in ERW materials, and their possible effects on pipeline safety, and offers some suggestions for continuing to operate such pipelines with a minimum of risk to the public.

Kiefner, J.F. (Kiefner and Associates Inc., Worthington, OH (US))

1992-08-10

31

OTEC Cold Water Pipe: Program, Problems, and Procedures.  

National Technical Information Service (NTIS)

The purpose of this presentation is to provide a comprehensive overview of the OTEC Cold Water Pipe program. The overview includes a discussion of the technical problems being addressed, the rationale behind the technology development program, and the ana...

T. McGuinness R. S. Scotti

1980-01-01

32

Benchmark Problems Used to Assess Computational Aeroacoustics Codes  

NASA Technical Reports Server (NTRS)

The field of computational aeroacoustics (CAA) encompasses numerical techniques for calculating all aspects of sound generation and propagation in air directly from fundamental governing equations. Aeroacoustic problems typically involve flow-generated noise, with and without the presence of a solid surface, and the propagation of the sound to a receiver far away from the noise source. It is a challenge to obtain accurate numerical solutions to these problems. The NASA Glenn Research Center has been at the forefront in developing and promoting the development of CAA techniques and methodologies for computing the noise generated by aircraft propulsion systems. To assess the technological advancement of CAA, Glenn, in cooperation with the Ohio Aerospace Institute and the AeroAcoustics Research Consortium, organized and hosted the Fourth CAA Workshop on Benchmark Problems. Participants from industry and academia from both the United States and abroad joined to present and discuss solutions to benchmark problems. These demonstrated technical progress ranging from the basic challenges to accurate CAA calculations to the solution of CAA problems of increasing complexity and difficulty. The results are documented in the proceedings of the workshop. Problems were solved in five categories. In three of the five categories, exact solutions were available for comparison with CAA results. A fourth category of problems representing sound generation from either a single airfoil or a blade row interacting with a gust (i.e., problems relevant to fan noise) had approximate analytical or completely numerical solutions. The fifth category of problems involved sound generation in a viscous flow. In this case, the CAA results were compared with experimental data.

Dahl, Milo D.; Envia, Edmane

2005-01-01

33

The rotating movement of three immiscible fluids - A benchmark problem  

USGS Publications Warehouse

A benchmark problem involving the rotating movement of three immiscible fluids is proposed for verifying the density-dependent flow component of groundwater flow codes. The problem consists of a two-dimensional strip in the vertical plane filled with three fluids of different densities separated by interfaces. Initially, the interfaces between the fluids make a 45??angle with the horizontal. Over time, the fluids rotate to the stable position whereby the interfaces are horizontal; all flow is caused by density differences. Two cases of the problem are presented, one resulting in a symmetric flow field and one resulting in an asymmetric flow field. An exact analytical solution for the initial flow field is presented by application of the vortex theory and complex variables. Numerical results are obtained using three variable-density groundwater flow codes (SWI, MOCDENS3D, and SEAWAT). Initial horizontal velocities of the interfaces, as simulated by the three codes, compare well with the exact solution. The three codes are used to simulate the positions of the interfaces at two times; the three codes produce nearly identical results. The agreement between the results is evidence that the specific rotational behavior predicted by the models is correct. It also shows that the proposed problem may be used to benchmark variable-density codes. It is concluded that the three models can be used to model accurately the movement of interfaces between immiscible fluids, and have little or no numerical dispersion. ?? 2003 Elsevier B.V. All rights reserved.

Bakker, M.; Oude, Essink, G. H. P.; Langevin, C. D.

2004-01-01

34

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

35

AFMM solution to the benchmark radar tracking problem  

NASA Astrophysics Data System (ADS)

The paper describes a new approach for an adaptive update- rate-tracking algorithm for phased array radars. Since phased array radars have the ability to perform adaptive sampling of the target by radar beam positioning, proper control of radar has the potential for significantly improving many aspects associated with tracking of multiple maneuvering targets. An adaptive multiple model filter for tracking maneuvering targets has been designed for applications to the Benchmark Tracking Problem (BTP). The first Benchmark Problem has previously been solved with (alpha) - (beta) -filters, standard Kalman filters and two and three model IMM filters. The tracking algorithm used in this paper is an Adaptive Forgetting through Multiple Model filter (AFMM). AFMM is especially suited for tracking of dynamic system with jumping and rapidly changing parameters. It can be viewed as a particular way of implementing adaptive gains or adaptive forgetting factors for tracking. Two motion models have been used: a constant velocity and a 3D turning rate. Preliminary result indicate promising capabilities of the filter in solving the BTP. This paper presents results for the BTP solved with an AFMM filter.

Carlsson, Mattias J.; Laaksonen, Mika V.

1999-07-01

36

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

37

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

38

Benchmark problem for beam pointing control of phased array radar against maneuvering targets  

Microsoft Academic Search

Presents a benchmark problem for tracking maneuvering targets. The benchmark problem involves beam pointing control of a phased array (agile beam) radar against highly maneuvering targets. A testbed simulation program that includes the effects of target amplitude fluctuations, beamshape, missed detections, finite resolution, target maneuvers, and track loss is described. Limits on the position and maneuverability of the targets are

W. D. Blair; G. A. Watson; S. A. Hoffman

1994-01-01

39

Benchmark problems in nuclear data processing and utilization system for innovative reactors  

NASA Astrophysics Data System (ADS)

A nuclear data processing and utilization system has been developed for research and development of innovative reactors such as accelerator-driven systems. The system is able to handle JENDL-3.3, ENDF/B-VI, and JEFF-3.1 to generate pointwise and groupwise cross sections in several formats, and has a capability to perform criticality and shielding benchmarks. Verification of nuclear data is available by using various criticality and shielding benchmark problems selected from database such as ICSBEP and SINBAD. The system performance highly depends on the quality of benchmark problems so that appropriate benchmarks should be selected from existing database. However a number of adequate benchmarks are quite a few to verify nuclear data for application of the accelerator-driven systems. Hence that new measurement should be necessary concerning criticality and shielding benchmarks. In the JENDL high-energy file (JENDL/HE) project, the intermediate-energy nuclear data integral test working group of Japanese Nuclear Data Committee made critical review of existing benchmark problems for accelerator-driven systems and performed verification of nuclear data in JENDL/HE. In this paper, the scheme of benchmark procedure and the selected benchmarks in the nuclear data processing and utilization system have been described.

Yamano, Naoki; Fukahori, Tokio; Igashira, Masayuki

2006-06-01

40

PARTISN results for the C5G7 MOX benchmark problems  

Microsoft Academic Search

In early 2001 the Nuclear Energy Agency solicited participants for a proposed new benchmark. The benchmark, known as C5G7 MOX, is intended to be a basis to measure current transport code abilities in the treatment of reactor core problems without spatial homogenization. We have participated with the code transport code PARTISN. PARTISN (PARallel TIme Dependent SN), PARTISN solves the linear

J. A. Dahl; Raymond E. Alcouffe

2002-01-01

41

A benchmarking system for MBS simulation software: Problem standardization and performance measurement  

Microsoft Academic Search

Despite the importance given to the computational efficiency of multibody system (MBS) simulation tools, there is a lack of standard benchmarks to measure the performance of these kinds of software applications. Benchmarking is done on an individual basis: different sets of problems are used, and the procedures and conditions considered to measure computational efficiency are also different. In this scenario,

M. González; D. Dopico; U. Lugrís; J. Cuadrado

2006-01-01

42

Calculation of sample problems related to two-phase flow blowdown transients in pressure relief piping of a PWR pressurizer  

SciTech Connect

A method was published, based on the integral method of characteristics, by which the junction and boundary conditions needed in computation of a flow in a piping network can be accurately formulated. The method for the junction and boundary conditions formulation together with the two-step Lax-Wendroff scheme are used in a computer program; the program in turn, is used here in calculating sample problems related to the blowdown transient of a two-phase flow in the piping network downstream of a PWR pressurizer. Independent, nearly exact analytical solutions also are obtained for the sample problems. Comparison of the results obtained by the hybrid numerical technique with the analytical solutions showed generally good agreement. The good numerical accuracy shown by the results of our scheme suggest that the hybrid numerical technique is suitable for both benchmark and design calculations of PWR pressurizer blowdown transients.

Shin, Y.W.; Wiedermann, A.H.

1984-02-01

43

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

44

Levermore-Pomraning Model Results for an Interior Source Binary Stochastic Medium Benchmark Problem  

SciTech Connect

The accuracy of the Levermore-Pomraning model for particle transport through a binary stochastic medium is investigated using an interior source benchmark problem. As in previous comparisons of the model for incident angular flux benchmark problems, the model accurately computes the leakage and the scalar flux distributions for optically thin slabs. The model is less accurate for more optically thick slabs but has a maximum relative error in the leakage of approximately 10% for the problems examined. The maximum root-mean-squared relative errors for the total and material scalar flux distributions approach 65% for the more optically thick slabs. Consistent with previous benchmark comparisons, the results of these interior source benchmark comparisons demonstrate that the Levermore-Pomraning model produces qualitatively correct and semi-quantitatively correct results for both leakage values and scalar flux distributions.

Brantley, P S; Palmer, T S

2009-02-24

45

Higher-order finite element discretizations in a benchmark problem for incompressible flows  

NASA Astrophysics Data System (ADS)

We present a numerical study of several finite element discretizations applied to a benchmark problem for the two-dimensional steady state incompressible Navier-Stokes equations defined in Schäfer and Turek (The benchmark problem Flow around a cylinder. In Flow Simulation with High-Performance Computers II. Notes on Numerical Fluid Mechanics, vol. 52, Hirschel EH (ed.). Vieweg: Wiesbaden, 1996; 547-566). The discretizations are compared with respect to the accuracy of the computed benchmark parameters. Higher-order isoparametric finite element discretizations turned out to be by far the most accurate. The discrete systems obtained with higher-order discretizations are solved with a modified coupled multigrid method whose behaviour within the benchmark problem is also studied numerically. Copyright

John, Volker; Matthies, Gunar

2001-12-01

46

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

47

HEATING6 analysis of international thermal benchmark problem sets 1 and 2  

SciTech Connect

In order to assess the heat transfer computer codes used in the analysis of nuclear fuel shipping casks, the Nuclear Energy Agency Committee on Reactor Physics has defined seven problems for benchmarking thermal codes. All seven of these problems have been solved using the HEATING6 heat transfer code. This report presents the results of five of the problems. The remaining two problems were used in a previous benchmarking of thermal codes used in the United States, and their solutions have been previously published.

Childs, K.W.; Bryan, C.B.

1986-10-01

48

Benchmarking Strategies for Measuring the Quality of Healthcare: Problems and Prospects  

PubMed Central

Over the last few years, increasing attention has been directed toward the problems inherent to measuring the quality of healthcare and implementing benchmarking strategies. Besides offering accreditation and certification processes, recent approaches measure the performance of healthcare institutions in order to evaluate their effectiveness, defined as the capacity to provide treatment that modifies and improves the patient's state of health. This paper, dealing with hospital effectiveness, focuses on research methods for effectiveness analyses within a strategy comparing different healthcare institutions. The paper, after having introduced readers to the principle debates on benchmarking strategies, which depend on the perspective and type of indicators used, focuses on the methodological problems related to performing consistent benchmarking analyses. Particularly, statistical methods suitable for controlling case-mix, analyzing aggregate data, rare events, and continuous outcomes measured with error are examined. Specific challenges of benchmarking strategies, such as the risk of risk adjustment (case-mix fallacy, underreporting, risk of comparing noncomparable hospitals), selection bias, and possible strategies for the development of consistent benchmarking analyses, are discussed. Finally, to demonstrate the feasibility of the illustrated benchmarking strategies, an application focused on determining regional benchmarks for patient satisfaction (using 2009 Lombardy Region Patient Satisfaction Questionnaire) is proposed.

Lovaglio, Pietro Giorgio

2012-01-01

49

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

50

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

51

Upper bounds on Taillard's benchmark suite for the no-wait flowshop scheduling problem with makespan criterion  

Microsoft Academic Search

In this paper, the discrete particle swarm optimization (DPSO) algorithm is employed to solve the no-wait flowshop scheduling problem with the makespan criterion for Taillardpsilas benchmark suite [1]. As known, there exist 31 benchmark instances provided by Carlier [2], Heller [3], and Revees [4] for the makespan criterion. However, these benchmarks are relatively small in size and easy to be

Quan-qe Pan; Mehmet Fatih Tasgetiren; Yun-chia Liang; Ponnuthurai N. Suganthan

2008-01-01

52

Benchmarking Problems Used in Second Year Level Organic Chemistry Instruction  

ERIC Educational Resources Information Center

Investigations of the problem types used in college-level general chemistry examinations have been reported in this Journal and were first reported in the "Journal of Chemical Education" in 1924. This study extends the findings from general chemistry to the problems of four college-level organic chemistry courses. Three problem typologies were…

Raker, Jeffrey R.; Towns, Marcy H.

2010-01-01

53

Least-Squares Spectral Element Solutions to the CAA Workshop Benchmark Problems  

NASA Technical Reports Server (NTRS)

This paper presents computed results for some of the CAA benchmark problems via the acoustic solver developed at Rocketdyne CFD Technology Center under the corporate agreement between Boeing North American, Inc. and NASA for the Aerospace Industry Technology Program. The calculations are considered as benchmark testing of the functionality, accuracy, and performance of the solver. Results of these computations demonstrate that the solver is capable of solving the propagation of aeroacoustic signals. Testing of sound generation and on more realistic problems is now pursued for the industrial applications of this solver. Numerical calculations were performed for the second problem of Category 1 of the current workshop problems for an acoustic pulse scattered from a rigid circular cylinder, and for two of the first CAA workshop problems, i. e., the first problem of Category 1 for the propagation of a linear wave and the first problem of Category 4 for an acoustic pulse reflected from a rigid wall in a uniform flow of Mach 0.5. The aim for including the last two problems in this workshop is to test the effectiveness of some boundary conditions set up in the solver. Numerical results of the last two benchmark problems have been compared with their corresponding exact solutions and the comparisons are excellent. This demonstrates the high fidelity of the solver in handling wave propagation problems. This feature lends the method quite attractive in developing a computational acoustic solver for calculating the aero/hydrodynamic noise in a violent flow environment.

Lin, Wen H.; Chan, Daniel C.

1997-01-01

54

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

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. This paper describes four benchmark problems to validate magnetohydrodynamic (MHD) and heat transfer computer codes. The problems include rectangular duct geometry with uniform and nonuniform magnetic fields, with and without surface heat flux, and various rectangular cross sections. Two of the problems are based on experiments. Participants in this benchmarking activity come from three countries: The Russian Federation, The United States, and Japan. The solution methods to the problems are described. Results from the different computer codes are presented and compared.

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, Hideo [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

1994-07-01

55

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

56

Benchmarking a Recurrent Linear GP Model on Prediction and Control Problems  

Microsoft Academic Search

In this work, a recurrent linear GP model is designed by introducing the concept of internal state to the standard linear\\u000a Genetic Programming (GP), so that it has the capacity of working on temporal sequence data. We benchmarked this model over\\u000a four standard prediction and control problems, which include generic even parity problem, sun spot series prediction, Lorenz\\u000a Chaotic time

Xiao Luo; Malcolm Heywood; A. Nur Zincir-Heywood

57

PARTISN results for the C5G7 MOX benchmark problems  

SciTech Connect

In early 2001 the Nuclear Energy Agency solicited participants for a proposed new benchmark. The benchmark, known as C5G7 MOX, is intended to be a basis to measure current transport code abilities in the treatment of reactor core problems without spatial homogenization. We have participated with the code transport code PARTISN. PARTISN (PARallel TIme Dependent SN), PARTISN solves the linear Boltzmann transport equation in static and time dependent forms on one, two and three dimensional orthogonal grids using the deterministic (SN) method. A variety of spatial discritization methods are incorporated into PARTISN, however all calculations performed here used the diamond difference approach, coupled with a volume fraction method for non-Cartesian problem geometries. Acceleration of the source iterations is accomplished with diffusion synthetic acceleration (DSA).

Dahl, J. A. (Jon A.); Alcouffe, Raymond E.

2002-01-01

58

Evaluation of a consistent point-kinetics model for the TMI-1 MSLB benchmark problem  

SciTech Connect

The SAS-DIF3DK coupled code system is currently being used for analyzing the Three Mile Island Unit 1 (TMI-1) main-steam-line-break (MSLB) benchmark problem sponsored by the Organization for Economic Cooperation and Development Nuclear Energy Agency, the US Nuclear Regulatory Commission, and the Pennsylvania State University. The code uses the DIF3D-K spatial kinetics module for calculating the detailed core power evolution during the transient. The current analysis of the benchmark problem focuses on exercise 2, in which performance of three-dimensional, coupled neutronic/thermal-hydraulic codes is being evaluated. For this exercise, thermal-hydraulic boundary conditions are prescribed. Other exercises are defined to model the whole reactor system using point kinetics (exercise 1) and multidimensional kinetics (exercise 3) for calculating the power evolution. These exercises are useful for evaluating the accuracy of the point-kinetics schemes currently used in the nuclear industry for analyzing such transient scenarios.

Taiwo, T.A.; Dunn, F.E.; Cahalan, J.E. [Argonne National Lab., IL (United States)

1999-09-01

59

3D radiation transport benchmark problems and results for simple geometries with void region  

Microsoft Academic Search

Three-dimensional (3D) transport benchmark problems for simple geometries with void region were proposed at the OECD\\/NEA in order to check the accuracy of deterministic 3D transport programs. The exact total fluxes by the analytical method are given for the pure absorber cases, and Monte Carlo values are given for the 50% scattering cases as the reference values. The total fluxes

Yasunobu Nagaya; Naoki Sugimura

2001-01-01

60

The classical dipole-wall collision as a numerical benchmark problem  

Microsoft Academic Search

The numerical experiment on the collision of a dipole and a no-slip boundary provides a well-defined problem needed for benchmarking numerical methods, as well gives insight on vortex wall interactions. Simulations are performed on a square domain bounded by no-slip walls with a finite-difference code and a Chebyshev pseudo-spectral method, and for a periodic channel with no-slip boundaries using a

Werner Kramer; Herman Clercx; Charles-Henri Bruneau

2004-01-01

61

2D - Numerical Simulation Results of Magnetic Flux Leakage Benchmark Problem 1  

NASA Astrophysics Data System (ADS)

Three typical nondestructive benchmark problems on MFL testing modeling were proposed by the World Federation of Nondestructive Evaluation Centers to compare the numerical techniques used by different Federation Members, and validate them against experimental measurements. Results obtained with a 2D-version of EFCAD with a regular mesh generator are presented here. These results compare well with those from the 3D simulations of the ISU and PUC groups presented at a previous conference.

Ruch, Marta; Bastos, Joa~O. P. A.

2005-04-01

62

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

63

Benchmark calculations on the phase II problem of uncertainty analyses for criticality safety assessment  

SciTech Connect

The phase II benchmark problem of expert group UACSA includes a configuration of a PWR fuel storage rack and focuses on the uncertainty of criticality from manufacturing tolerance of design parameters such as fuel enrichment, density, diameter, thickness of neutron absorber and structural material, and so on. It provides probability density functions for each design parameter. In this paper, upper limits of k{sub eff} of 95%/95% tolerance with two methods are calculated by sampling design parameters using given probability distributions and compared with the result from traditional approach. (authors)

Lee, G. S.; Lee, J.; Kim, G. Y.; Woo, S. W. [Korea Inst. of Nuclear Safety, 62 Gwahak-ro, Yuseong-gu, Daejeon, 305-338 (Korea, Republic of)

2012-07-01

64

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

65

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.

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

2014-01-01

66

Elimination or control of material problems in water heat pipes. Final report, January 1, 1974March 30, 1976  

Microsoft Academic Search

A definition was made of a water heat pipe for use with a parabolic cylindrical solar collector that will operate in the temperature range of ambient to 300°C, and a literature survey was conducted on the problem of noncondensable gas generation in water heat pipes. Heat pipes measuring 76 cm long were fabricated from 316 SS, 347 SS, 430 SS,

Pittinato

1976-01-01

67

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

68

New ideas, methods address serious piping-seam problems  

SciTech Connect

This article describes how failures in longitudinal seam welds in particular have focused attention on inspection techniques as well as on study of basic failure mechanisms. The threat of ruptures in longitudinal welded seams of high-energy steam lines is still spurring search for improved non-destructive flaw-detection methods, evaluation standards, and way of predicting the progression of flaws. The inspections are expensive. The inspections must be none, however, and plants must find and monitor potentially disastrous flaws. At present, ultrasonic examination is still the most common technique and is undergoing steady improvement, but other methods are being adapted to pipe-seam inspection. For example, there is now some ability to size subsurface flaws reliably--important because the dimension in the through-wall direction is a factor in determining crack growth and re-inspection schedules.

O`Keefe, W.

1995-02-01

69

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

70

Integrating CFD, CAA, and Experiments Towards Benchmark Datasets for Airframe Noise Problems  

NASA Technical Reports Server (NTRS)

Airframe noise corresponds to the acoustic radiation due to turbulent flow in the vicinity of airframe components such as high-lift devices and landing gears. The combination of geometric complexity, high Reynolds number turbulence, multiple regions of separation, and a strong coupling with adjacent physical components makes the problem of airframe noise highly challenging. Since 2010, the American Institute of Aeronautics and Astronautics has organized an ongoing series of workshops devoted to Benchmark Problems for Airframe Noise Computations (BANC). The BANC workshops are aimed at enabling a systematic progress in the understanding and high-fidelity predictions of airframe noise via collaborative investigations that integrate state of the art computational fluid dynamics, computational aeroacoustics, and in depth, holistic, and multifacility measurements targeting a selected set of canonical yet realistic configurations. This paper provides a brief summary of the BANC effort, including its technical objectives, strategy, and selective outcomes thus far.

Choudhari, Meelan M.; Yamamoto, Kazuomi

2012-01-01

71

Helmholtz and parabolic equation solutions to a benchmark problem in ocean acoustics.  

PubMed

The Helmholtz equation (HE) describes wave propagation in applications such as acoustics and electromagnetics. For realistic problems, solving the HE is often too expensive. Instead, approximations like the parabolic wave equation (PE) are used. For low-frequency shallow-water environments, one persistent problem is to assess the accuracy of the PE model. In this work, a recently developed HE solver that can handle a smoothly varying bathymetry, variable material properties, and layered materials, is used for an investigation of the errors in PE solutions. In the HE solver, a preconditioned Krylov subspace method is applied to the discretized equations. The preconditioner combines domain decomposition and fast transform techniques. A benchmark problem with upslope-downslope propagation over a penetrable lossy seamount is solved. The numerical experiments show that, for the same bathymetry, a soft and slow bottom gives very similar HE and PE solutions, whereas the PE model is far from accurate for a hard and fast bottom. A first attempt to estimate the error is made by computing the relative deviation from the energy balance for the PE solution. This measure gives an indication of the magnitude of the error, but cannot be used as a strict error bound. PMID:12765364

Larsson, Elisabeth; Abrahamsson, Leif

2003-05-01

72

Higher order finite element methods and multigrid solvers in a benchmark problem for the 3D Navier-Stokes equations  

NASA Astrophysics Data System (ADS)

This paper presents a numerical study of the 3D flow around a cylinder which was defined as a benchmark problem for the steady state Navier-Stokes equations within the DFG high-priority research program flow simulation with high-performance computers by Schafer and Turek (Vol. 52, Vieweg: Braunschweig, 1996). The first part of the study is a comparison of several finite element discretizations with respect to the accuracy of the computed benchmark parameters. It turns out that boundary fitted higher order finite element methods are in general most accurate. Our numerical study improves the hitherto existing reference values for the benchmark parameters considerably. The second part of the study deals with efficient and robust solvers for the discrete saddle point problems. All considered solvers are based on coupled multigrid methods. The flexible GMRES method with a multiple discretization multigrid method proves to be the best solver.

John, Volker

2002-10-01

73

Study shows shift in line pipe service problems  

SciTech Connect

Research before 1979 adequately described the causes of degradation in gas transmission pipelines that have led to failures. Although more current research has shown to new failure causes, many variations have been identified. They are covered in this article. Between 1979 and 1986, the new types of service problems that have been experienced are due to: Hydrogen effects causing failure of the steel; Long ductile fracture propagation in a 16-in.-diameter line; Bacterial corrosion. Causes of failure have been divided into two categories: those associated with both preservice test failures and with service failures. A table summarizes the types of defects that have caused pipeline incidents.

Kiefner, J.F.; Eiber, R.J.

1987-03-30

74

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

NASA Astrophysics Data System (ADS)

Computer models must be tested to ensure that the mathematical statements and solution schemes accurately represent the physical processes of interest. Because the availability of benchmark problems for testing density-dependent groundwater models is limited, one should be careful in using these problems appropriately. Details of a Galerkin finite-element model for the simulation of density-dependent, variably saturated flow processes are presented here. The model is tested using the Henry salt-water intrusion problem and Elder salt convection problem. The quality of these benchmark problems is then evaluated by solving the problems in the standard density-coupled mode and in a new density-uncoupled mode. The differences between the solutions indicate that the Henry salt-water intrusion problem has limited usefulness in benchmarking density-dependent flow models because the internal flow dynamics are largely determined by the boundary forcing. Alternatively, the Elder salt-convection problem is more suited to the model testing process because the flow patterns are completely determined by the internal balance of pressure and gravity forces.

Simpson, M. J.; Clement, T. P.

75

Application of PML Absorbing Boundary Conditions to the Benchmark Problems of Computational Aeroacoustics  

NASA Technical Reports Server (NTRS)

Accurate numerical non-reflecting boundary conditions are important in all the proposed benchmark problems of the Second Workshop. Recently, a new absorbing boundary condition has been developed using Perfectly Matched Layer (PML) equations for the Euler equations. In this approach, a region with a width of a few grid points is introduced adjacent to the non-reflecting boundaries. In the added region, Perfectly Matched Layer equations are constructed and applied so that the out-going waves are absorbed inside the layer with little reflection to the interior domain. It will be demonstrated in the present paper that the proposed absorbing boundary condition is quite general and versatile, applicable to radiation boundaries as well as inflow and outflow boundaries. It is also easy to implement. The emphasis of the paper will be on the application of the PML absorbing boundary condition to problems in Categories 1, 2, and 3. In Category 1, solutions of problems 1 and 2 are presented. Both problems are solved using a multi-domain polar grid system. Perfectly Matched Layer equations for a circular boundary are constructed and their effectiveness assessed. In Category 2, solutions of problem 2 are presented. Here, in addition to the radiation boundary conditions at the far field in the axisymmetric coordinate system, the inflow boundary condition at the duct inlet is also dealt with using the proposed Perfectly Match Layer equations. At the inlet, a PML domain is introduced in which the incident duct mode is simulated while the waves reflected from the open end of the duct are absorbed at the same time. In Category 3, solutions of all three problems are presented. Again, the PML absorbing boundary condition is used at the inflow boundary so that the incoming vorticity wave is simulated while the outgoing acoustic waves are absorbed with very little numerical reflection. All the problems are solved using central difference schemes for spatial discretizations and the optimized Low-Dissipation and Low-Dispersion Runge-Kutta scheme for the time integration. Issues of numerical accuracy and efficiency are also addressed.

Hu, Fang Q.; Manthey, Joe L.

1997-01-01

76

Benchmark problem for beam pointing control of phased array radar against maneuvering targets in the presence of ECM and false alarms  

Microsoft Academic Search

This paper extends an earlier benchmark problem for beam pointing control of a phased array radar to include the effects of false alarms and ECM. Multiple waveforms are included in the benchmark problem so that the radar energy can be coordinated with the tracking algorithm. The ECM includes a standoff jammer broadcasting wideband noise and targets attempting range gate pull

W. D. Blair; Watson G. L. Gentry; G. L. Gentry; S. A. Hoffman

1995-01-01

77

Numerical Prediction of Signal for Magnetic Flux Leakage Benchmark Task  

NASA Astrophysics Data System (ADS)

Numerical results predicted by the finite element method based code are presented. The nonlinear magnetic time-dependent benchmark problem proposed by the World Federation of Nondestructive Evaluation Centers, involves numerical prediction of normal (radial) component of the leaked field in the vicinity of two practically rectangular notches machined on a rotating steel pipe (with known nonlinear magnetic characteristic). One notch is located on external surface of pipe and other is on internal one, and both are oriented axially.

Lunin, V.; Alexeevsky, D.

2003-03-01

78

OTEC cold water pipe design for problems caused by vortex-excited oscillations  

SciTech Connect

Vortex-excited oscillations of marine structures result in reduced fatigue life, large hydrodynamic forces and induced stresses, and sometimes lead to structural damage and to diestructive failures. The cold water pipe of an OTEC plant is nominally a bluff, flexible cylinder with a large aspect ratio (L/D = length/diameter), and is likely to be susceptible to resonant vortex-excited oscillations. The objective of this report is to survey recent results pertaining to the vortex-excited oscillations of structures in general and to consider the application of these findings to the design of the OTEC cold water pipe. Practical design calculations are given as examples throughout the various sections of the report. This report is limited in scope to the problems of vortex shedding from bluff, flexible structures in steady currents and the resulting vortex-excited oscillations. The effects of flow non-uniformities, surface roughness of the cylinder, and inclination to the incident flow are considered in addition to the case of a smooth cyliner in a uniform stream. Emphasis is placed upon design procedures, hydrodynamic coefficients applicable in practice, and the specification of structural response parameters relevant to the OTEC cold water pipe. There are important problems associated with in shedding of vortices from cylinders in waves and from the combined action of waves and currents, but these complex fluid/structure interactions are not considered in this report.

Griffin, O. M.

1980-03-14

79

Benchmark problem for IAEA coordinated research program (CRP-3) on GCR afterheat removal. 1.  

National Technical Information Service (NTIS)

In this report, detailed data which are necessary for the benchmark analysis of International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP-3) on 'Heat Transport and Afterheat Removal for Gas-cooled Reactors under Accident Conditions' are ...

S. Takada Y. Shiina Y. Inagaki M. Hishida Y. Sudo

1995-01-01

80

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

81

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

82

Benchmark solutions for the natural convective heat transfer problem in a square cavity with large horizontal temperature differences  

Microsoft Academic Search

In this study, Benchmark solutions are derived for the problem of two-dimensional laminar flow of air in a square cavity which is heated on the left, cooled on the right and insulated on the top and bottom boundaries. The temperature differences between the hot and cold walls are large. Neither Boussinesq nor low-Mach number approximations of the Navier-Stokes equations are

Jan Vierendeels; Bart Merci; Erik Dick

2003-01-01

83

Evaluating Heat Pipe Performance in 1/6 g Acceleration: Problems and Prospects  

NASA Technical Reports Server (NTRS)

Heat pipes composed of titanium and water are being considered for use in the heat rejection system of a fission power system option for lunar exploration. Placed vertically on the lunar surface, the heat pipes would operate as thermosyphons in the 1/6 g environment. The design of thermosyphons for such an application is determined, in part, by the flooding limit. Flooding is composed of two components, the thickness of the fluid film on the walls of the thermosyphon and the interaction of the fluid flow with the concurrent vapor counter flow. Both the fluid thickness contribution and interfacial shear contribution are inversely proportional to gravity. Hence, evaluating the performance of a thermosyphon in a 1 g environment on Earth may inadvertently lead to overestimating the performance of the same thermosyphon as experienced in the 1/6 g environment on the moon. Several concepts of varying complexity have been proposed for evaluating thermosyphon performance in reduced gravity, ranging from tilting the thermosyphons on Earth based on a cosine function, to flying heat pipes on a low-g aircraft. This paper summarizes the problems and prospects for evaluating thermosyphon performance in 1/6 g.

Jaworske, Donald A.; McCollum, Timothy A.; Gibson, Marc A.; Sanzi, James L.; Sechkar, Edward A.

2011-01-01

84

The elimination or control of material problems in water heat pipes  

Microsoft Academic Search

Several different concepts for using solar energy involve the use of heat pipes to transport energy within the systems. Two 347 SS water heat pipes measuring 86.5 cm long were fabricated with one of the pipes containing a 200 mesh 347 SS screen wick. Fourteen additional heat pipes measuring 76 cm long were also fabricated, two from each of the

G. F. Pittinato

1974-01-01

85

Elimination or control of material problems in water heat pipes. Annual progress report, January 1December 31, 1974  

Microsoft Academic Search

This report documents the research and development efforts conducted at McDonnell Douglas Astronautics Company on water heat pipes from January 1 to December 31, 1974. A definition was made of water heat pipe associated with a parabolic cylindrical solar collector that will operate in the temperature range of ambient to 300°C. A literature survey was conducted on the problem of

Pittinato

1975-01-01

86

USS Princeton (CG 59): Impact of Marine Macrofouling (Mussels and Hydroids) on Failures/Corrosion Problems in Seawater Piping Systems.  

National Technical Information Service (NTIS)

The presentation summarized some of the information that will be released as NAVSWC TR 90-176 on macrofouling problems within the seawater piping system of the USS PRINCETON (CG 59) and its contribution to the failures/corrosion problems observed. Some se...

B. J. Little J. M. Jones

1990-01-01

87

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

88

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

89

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

90

Two and Three Dimensional Nonlocal DFT for Inhomogeneous Fluids II: Solvated Polymers as a Benchmark Problem  

SciTech Connect

In a previous companion paper, we presented the details of our algorithms for performing nonlocal density functional theory (DFT) calculations in complex 2D and 3D geometries. We discussed scaling and parallelization, but did not discuss other issues of performance. In this paper, we detail the precision of our methods with respect to changes in the mesh spacing. This is a complex issue because given a Cartesian mesh, changes in mesh spacing will result in changes in surface geometry. We discuss these issue using a series of rigid solvated polymer models including square rod polymers, cylindrical polymers, and bead-chain polymers. By comparing the results of the various models, it becomes clear that surface curvature or roughness plays an important role in determining the strength of structural solvation forces between interacting solvated polymers. The results in this paper serve as benchmarks for future application of these algorithms to complex fluid systems.

Frink, Laura J. Douglas; Salinger, Andrew G.

1999-08-09

91

Verification of Core Mechanical Performance Code ARKAS with IAEA Benchmark Problems  

Microsoft Academic Search

Verification of the “ARKAS” code, using problems defined in the IWGFR Coordinated Research Programme (CRP) on the comparison between LMFBR Core Mechanics Codes, is discussed. The problems of verification were defined and calculated by 11 core mechanics codes from 9 countries. A comparison of the solutions obtained by these codes was carried out as Stage 1 of the CRP. This

Masatoshi NAKAGAWA

1991-01-01

92

Verification and Validation of Core Mechanical Performance Code ARKAS with IAEA Benchmark Problems, (II)  

Microsoft Academic Search

Verification and validation of the “ARKAS” code, using problems defined in the IWGFR Coordinated Research Programme (CRP) for the comparison of LMFBR Core Mechanics Codes, are discussed. The problems to be used in the verification (code against code) and validation (code against experiment) were defined and calculated by 11 core mechanics codes from 9 countries. The solutions obtained by these

Masatoshi NAKAGAWA

1993-01-01

93

Evaluating Heat Pipe Performance in 1/6 g Acceleration: Problems and Prospects.  

National Technical Information Service (NTIS)

Heat pipes composed of titanium and water are being considered for use in the heat rejection system of a fission power system option for lunar exploration. Placed vertically on the lunar surface, the heat pipes would operate as thermosyphons in the 1/6 g ...

D. A. Jaworske E. A. Sechkar J. L. Sanzi M. A. Gibson T. A. McCollum

2011-01-01

94

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

95

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

Microsoft Academic Search

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

L. T. Wilson; E. Hertel; L. Schwalbe; C. Wingate

1998-01-01

96

Transient heat-pipe modeling - The frozen start-up problem  

NASA Astrophysics Data System (ADS)

This paper describes work to better understand numerical modeling of heat-pipe transients. Two methods of modeling liquid thawing are discussed. For one model, the solid/liquid phase change process is modeled using an effective specific heat capacity method. For the other model, an energy sink equal to the heat of fusion is used to account for the energy associated with the phase change process. The later method worked best. Also, two methods of modeling friction between the vapor and the heat-pipe wall are studied. Both methods gave comparable results. Results from the numerical models are compared to experimental results for two different heat-pipes started from a frozen state.

Bowman, W. Jerry

1990-06-01

97

Making Benchmark Testing Work  

ERIC Educational Resources Information Center

Many schools are moving to develop benchmark tests to monitor their students' progress toward state standards throughout the academic year. Benchmark tests can provide the ongoing information that schools need to guide instructional programs and to address student learning problems. The authors discuss six criteria that educators can use to…

Herman, Joan L.; Baker, Eva L.

2005-01-01

98

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

99

OTEC cold water pipe design for problems caused by vortex-excited oscillations  

Microsoft Academic Search

The objective of this paper is to survey recent results pertaining to the vortex-excited oscillations of structures in general and to consider the application of these findings to the design of the OTEC Ocean Thermal Energy Conversion cold water pipe. Practical design calculations are given as examples throughout the various sections of the report. This paper is limited in scope

O GRIFFIN

1981-01-01

100

Analysis of chlorinated polyvinyl chloride pipe burst problems :Vasquez residence system inspection.  

SciTech Connect

This report documents the investigation regarding the failure of CPVC piping that was used to connect a solar hot water system to standard plumbing in a home. Details of the failure are described along with numerous pictures and diagrams. A potential failure mechanism is described and recommendations are outlined to prevent such a failure.

Black, Billy D.; Menicucci, David F.; Harrison, John (Florida Solar Energy Center)

2005-10-01

101

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

102

Comparison of numerical methods for simulating strongly nonlinear and heterogeneous reactive transport problems—the MoMaS benchmark case  

Microsoft Academic Search

Although multicomponent reactive transport modeling is gaining wider application in various geoscience fields, it continues\\u000a to present significant mathematical and computational challenges. There is a need to solve and compare the solutions to complex\\u000a benchmark problems, using a variety of codes, because such intercomparisons can reveal promising numerical solution approaches\\u000a and increase confidence in the application of reactive transport codes.

Jérôme Carrayrou; Joachim Hoffmann; Peter Knabner; Serge Kräutle; Caroline de Dieuleveult; Jocelyne Erhel; Jan Van der Lee; V. Lagneau; K. Ulrich Mayer; Kerry T. B. MacQuarrie

2010-01-01

103

Inhomogeneous temperature problems inside a Li/SOCl2 cell - Homogenization by integrated heat pipes  

SciTech Connect

The effect of the temperature gradient on the electrical capacity of the lithium/thionyl chloride (Li/SOCl2) cells and the dependence of internal heat generation on the temperature level were investigated by studying the thermal behavior of a cell constituted by a number of couples stacken in a stainless steel cylinder during a discharge profile. It is shown that the temperature gradient between couples affected the depth of discharge, indicating that this gradient must be limited to prevent discrepancy in couple's voltage and inversion phenomenon. It was found that a cooling concept based on integrated heat pipes is effective in reducing the temperature gradient and in yielding homogeneous cell behavior in overdischarge. 6 refs.

Lefriec, C.; Suleiman, A.; Alexandre, A.

1992-01-01

104

Nas Parallel Benchmark Results 3-94  

Microsoft Academic Search

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

David H. Bailey; Eric Barszcz; Leonardo Dagum; Horst D. Simon

1994-01-01

105

Nonlinear fluid flows in pipe-like domain problem using variational-iteration method  

Microsoft Academic Search

The propagation of nonlinear waves in viscoelastic tube filled with incompressible viscous fluid is investigated. Various modified KdV equations and modified Burger equations derived from the discussed problem are solved analytically by He’s variational-iteration method.

Essam M. Abulwafa; M. A. Abdou; Aber A. Mahmoud

2007-01-01

106

Analysis of the OECD Main Steam Line Break Benchmark Problem Using the Refined Core Thermal-Hydraulic Nodalization Feature of the MARS/MASTER Code  

SciTech Connect

The refined core thermal-hydraulics (T-H) nodalization feature of the MARS/MASTER code is used to generate a high-fidelity solution to the OECD main steam line break benchmark problem and to investigate the effects of core T-H nodalization. The MARS/MASTER coupling scheme is introduced first that enables efficient refined node core T-H calculations via the COBRA-III module. The base solution is generated using a fine T-H nodalization consisting of fuel assembly-sized radial nodes. Sensitivity studies are performed on core T-H nodalization to examine the impacts on core reactivity, power distribution, and transient behavior. The results indicate that the error in the peak local power can be very large (up to 25%) with a coarse T-H nodalization because of the inability to incorporate detailed thermal feedback. A demonstrative departure from nucleate boiling (DNB) calculation shows no occurrence of DNB in this problem.

Joo, Han Gyu; Jeong, Jae-Jun; Cho, Byung-Oh; Lee, Won Jae; Zee, Sung Quun [Korea Atomic Energy Research Institute (Korea, Republic of)

2003-05-15

107

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

108

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

109

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

110

A heterogeneous coarse mesh solution for the 2-D NEA C5G7 mox benchmark problem  

Microsoft Academic Search

This paper presents a transport solution to the C5G7 2-Dbenchmark problem using a Monte Carlo adaptation of a heterogeneous coarse mesh transport method. The method couples Monte Carlo response function calculations to deterministic sweeps for converging the partial currents on coarse mesh boundaries. The propagation of statistical uncertainties is accounted for in a straightforward fashion. Presently, eigenvalue iterations have been

Benoit Forget; Farzad Rahnema; Scott W. Mosher

2004-01-01

111

Range Graphics Benchmark.  

National Technical Information Service (NTIS)

This document will detail the various avenues available to the government in determining what benchmarks are applicable to the test range community. Areas explored include vendor benchmarks, government developed benchmarks, third party benchmarks, and pro...

1995-01-01

112

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

113

Benchmarking Reference Services  

Microsoft Academic Search

This article is a companion to an introductory article on benchmarking published in an earlier issue of Medical Reference Services Quarterly. Librarians interested in benchmarking often ask the following questions: How do I determine what to benchmark; how do I form a benchmarking team; how do I identify benchmarking partners; what's the best way to collect and analyze benchmarking information;

Holly Shipp Buchanan; Joanne G. Marshall

1996-01-01

114

Miniature Heat Pipes  

NASA Technical Reports Server (NTRS)

Small Business Innovation Research contracts from Goddard Space Flight Center to Thermacore Inc. have fostered the company work on devices tagged "heat pipes" for space application. To control the extreme temperature ranges in space, heat pipes are important to spacecraft. The problem was to maintain an 8-watt central processing unit (CPU) at less than 90 C in a notebook computer using no power, with very little space available and without using forced convection. Thermacore's answer was in the design of a powder metal wick that transfers CPU heat from a tightly confined spot to an area near available air flow. The heat pipe technology permits a notebook computer to be operated in any position without loss of performance. Miniature heat pipe technology has successfully been applied, such as in Pentium Processor notebook computers. The company expects its heat pipes to accommodate desktop computers as well. Cellular phones, camcorders, and other hand-held electronics are forsible applications for heat pipes.

1997-01-01

115

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

116

Heat pipe development status  

SciTech Connect

Test heat pipes have been operated in the 1400 K to 1700 K range for periods in excess of 20,000 hours with the objective of understanding and controlling corrosion and failure mechanisms. The results of a post test analysis of one of these heat pipes that was operated for 25,216 hours at 1700 K are reviewed and the implications for heat pipe lifetime discussed. An in-process report of an investigation of transient heat pipe behavior is presented. This investigation is being conducted as a result of restart problems encountered during life test of a 2 m. radiation cooled heat pipe. The results of a series of shut-down tests from power and temperature are given and probable causes of the restart problem discussed.

Merrigan, M.A.

1984-01-01

117

Drowning - a scientometric analysis and data acquisition of a constant global problem employing density equalizing mapping and scientometric benchmarking procedures  

PubMed Central

Background Drowning is a constant global problem which claims approximately half a million victims worldwide each year, whereas the number of near-drowning victims is considerably higher. Public health strategies to reduce the burden of death are still limited. While research activities in the subject drowning grow constantly, yet there is no scientometric evaluation of the existing literature at the present time. Methods The current study uses classical bibliometric tools and visualizing techniques such as density equalizing mapping to analyse and evaluate the scientific research in the field of drowning. The interpretation of the achieved results is also implemented in the context of the data collection of the WHO. Results All studies related to drowning and listed in the ISI-Web of Science database since 1900 were identified using the search term "drowning". Implementing bibliometric methods, a constant increase in quantitative markers such as number of publications per state, publication language or collaborations as well as qualitative markers such as citations were observed for research in the field of drowning. The combination with density equalizing mapping exposed different global patterns for research productivity and the total number of drowning deaths and drowning rates respectively. Chart techniques were used to illustrate bi- and multilateral research cooperation. Conclusions The present study provides the first scientometric approach that visualizes research activity on the subject of drowning. It can be assumed that the scientific approach to this topic will achieve even greater dimensions because of its continuing actuality.

2011-01-01

118

Benchmark Glaciers  

NSDL National Science Digital Library

The United States Geological Survey (USGS) operates a long-term "benchmark" glacier program to intensively monitor climate, glacier motion, glacier mass balance, glacier geometry, and stream runoff at a few select sites. The data collected are used to understand glacier-related hydrologic processes and improve the quantitative prediction of water resources, glacier-related hazards, and the consequences of climate change. This page presents some of the balance, runoff, and temperature data for three glaciers: Gulkana, South Cascade and Wolverine. Reports for each of these glaciers uses the collected data to draw many conclusions. There is also a section with common questions and myths about glaciers.

119

The Nas Parallel Benchmarks  

Microsoft Academic Search

A new set of benchmarks has been developed for the performance evaluation of highly parallel supercomputers. These benchmarks consist of five parallel kernels and three simulated application benchmarks. Together theymimic the computation and data movement characteristics of large scale computational fluid dynamics (CFD) applications.The principal distinguishing feature of these benchmarks is their penciland paper specification---all details of these benchmarks are

D. Bailey; E. Barszcz; J. Barton; D. Browning; R. Carter; L. Dagum

1994-01-01

120

Ceramic heat pipe development  

NASA Astrophysics Data System (ADS)

Ceramic materials used in conventional brickwork heat exchanger configurations increase allowable temperatures; however, joint leakage problems limit use of these designs. Ceramic tube heat exchanger designs reduce these problems but still require sliding joints and compliant tube end seals. Ceramic heat pipe based recuperator designs eliminate the sealing problems that limited the high temperature heat recovery installations. Heat pipe recuperators offer high corrosion and abrasion resistance, high temperature capability, reduced leakage, element redundancy, and simplified replacement and cleaning. The development of ceramic heat pipe recuperator elements involves the selection and test of materials and fabrication techniques having production potential, evaluation of technology in subscale tests, design and test of components for full scale recuperator applications, and demonstration of heat pipes in subscale and full scale recuperator installation.

Merrigan, M.

1980-09-01

121

A study of circumferentially-heated and block-heated heat pipes. I - Experimental analysis and generalized analytical prediction of capillary limits. II - Three-dimensional numerical modeling as a conjugate problem  

NASA Technical Reports Server (NTRS)

The wall and centerline vapor temperatures and heat output are determined experimentally for a low-temperature copper-water heat pipe under uniform circumferential heating and block heating. The time required to reach a vapor temperature of 60 C from an initial ambient temperature of 21 C is determined for both modes of heating. The experimental capillary limit of the heat pipe is compared to the generalized capillary limits for block-heated pipes over a range of vapor temperatures. A three-dimensional numerical model is then developed for determining the temperature, pressure, and velocity distributions in the entire domain of a circumferentially heated and a block-heated pipe. The problem is formulated as a conjugate problem, without the assumption of a uniform vapor temperature. The predictions of the model are found to be in good agreement with the experimental data.

Schmalhofer, Joseph; Faghri, Amir

1993-01-01

122

The DARPA Dynamic Programming Benchmark on a Reconfigurable Computer  

Microsoft Academic Search

The Defense Advanced Research Projects Agency (DARPA) has released high productivity computing systems (HPCS) benchmarks as specifications of performance required to solve important problems. This work reports on the design, implementation, and benchmarking of the benchmark number two, dynamic programming (DP), as developed in a general purpose reconfigurable computer. DP methods are used to solve DNA sequencing problems. DP has

Luis E. Cordova; Duncan A. Buell; Sreesa Akella

2005-01-01

123

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

124

Heat Pipes  

ERIC Educational Resources Information Center

Describes the construction, function, and applications of heat pipes. Suggests using the heat pipe to teach principles related to heat transfer and gives sources for obtaining instructional kits for this purpose. (GS)

Lewis, J.

1975-01-01

125

Pipe Dreams.  

ERIC Educational Resources Information Center

Discusses the importance of attention to plumbing in college facilities, offering examples from various campuses. Addresses preventive maintenance, technology, and piping materials, including the debate between cast iron and PVC for drain pipes. (EV)

Milshtein, Amy

2002-01-01

126

Benchmarking in Student Affairs.  

ERIC Educational Resources Information Center

Discusses the use of benchmarking in student affairs, focusing on issues related to student housing. Provides examples of how benchmarking has influenced administrative practice at many institutions. (EV)

Mosier, Robert E.; Schwarzmueller, Gary J.

2002-01-01

127

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

128

Benchmarking methodologies applied to UK facilities management  

Microsoft Academic Search

The use of benchmarking is regarded by many as a panacea to modern day business problems. Irrespective of what business you are in, or the financial state of your business; proponents of the procedure insist benchmarking, if correctly applied, ensures organizations are able to gain the competitive edge necessary in today’s business world. But how can this technique be usefully

Keith Massheder; Edward Finch

1998-01-01

129

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

130

Perspective: Selected benchmarks from commercial CFD codes  

Microsoft Academic Search

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

C. J. Freitas

1995-01-01

131

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

132

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

133

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

134

Silicon Heat Pipe Array  

NASA Technical Reports Server (NTRS)

Improved methods of heat dissipation are required for modern, high-power density electronic systems. As increased functionality is progressively compacted into decreasing volumes, this need will be exacerbated. High-performance chip power is predicted to increase monotonically and rapidly with time. Systems utilizing these chips are currently reliant upon decades of old cooling technology. Heat pipes offer a solution to this problem. Heat pipes are passive, self-contained, two-phase heat dissipation devices. Heat conducted into the device through a wick structure converts the working fluid into a vapor, which then releases the heat via condensation after being transported away from the heat source. Heat pipes have high thermal conductivities, are inexpensive, and have been utilized in previous space missions. However, the cylindrical geometry of commercial heat pipes is a poor fit to the planar geometries of microelectronic assemblies, the copper that commercial heat pipes are typically constructed of is a poor CTE (coefficient of thermal expansion) match to the semiconductor die utilized in these assemblies, and the functionality and reliability of heat pipes in general is strongly dependent on the orientation of the assembly with respect to the gravity vector. What is needed is a planar, semiconductor-based heat pipe array that can be used for cooling of generic MCM (multichip module) assemblies that can also function in all orientations. Such a structure would not only have applications in the cooling of space electronics, but would have commercial applications as well (e.g. cooling of microprocessors and high-power laser diodes). This technology is an improvement over existing heat pipe designs due to the finer porosity of the wick, which enhances capillary pumping pressure, resulting in greater effective thermal conductivity and performance in any orientation with respect to the gravity vector. In addition, it is constructed of silicon, and thus is better suited for the cooling of semiconductor devices.

Yee, Karl Y.; Ganapathi, Gani B.; Sunada, Eric T.; Bae, Youngsam; Miller, Jennifer R.; Beinsford, Daniel F.

2013-01-01

135

Solar piping considerations: a simplified and more effective solar piping scheme  

Microsoft Academic Search

This article explores the piping problems and piping costs associated with the one large solar collector array on the North Campus Community College project presently under construction near Denver. (WDM)

Supple

1976-01-01

136

Benchmarking multimedia performance  

NASA Astrophysics Data System (ADS)

With the introduction of faster processors and special instruction sets tailored to multimedia, a number of exciting applications are now feasible on the desktops. Among these is the DVD playback consisting, among other things, of MPEG-2 video and Dolby digital audio or MPEG-2 audio. Other multimedia applications such as video conferencing and speech recognition are also becoming popular on computer systems. In view of this tremendous interest in multimedia, a group of major computer companies have formed, Multimedia Benchmarks Committee as part of Standard Performance Evaluation Corp. to address the performance issues of multimedia applications. The approach is multi-tiered with three tiers of fidelity from minimal to full compliant. In each case the fidelity of the bitstream reconstruction as well as quality of the video or audio output are measured and the system is classified accordingly. At the next step the performance of the system is measured. In many multimedia applications such as the DVD playback the application needs to be run at a specific rate. In this case the measurement of the excess processing power, makes all the difference. All these make a system level, application based, multimedia benchmark very challenging. Several ideas and methodologies for each aspect of the problems will be presented and analyzed.

Zandi, Ahmad; Sudharsanan, Subramania I.

1998-03-01

137

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.

138

Piping Flexibility  

NASA Technical Reports Server (NTRS)

A NASA computer program aids Hudson Engineering Corporation, Houston, Texas, in the design and construction of huge petrochemical processing plants like the one shown, which is located at Ju'aymah, Saudi Arabia. The pipes handling the flow of chemicals are subject to a variety of stresses, such as weight and variations in pressure and temperature. Hudson Engineering uses a COSMIC piping flexibility analysis computer program to analyze stresses and unsure the necessary strength and flexibility of the pipes. This program helps the company realize substantial savings in reduced engineering time.

1978-01-01

139

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

140

Cleanroom energy benchmarking results  

SciTech Connect

A utility market transformation project studied energy use and identified energy efficiency opportunities in cleanroom HVAC design and operation for fourteen cleanrooms. This paper presents the results of this work and relevant observations. Cleanroom owners and operators know that cleanrooms are energy intensive but have little information to compare their cleanroom's performance over time, or to others. Direct comparison of energy performance by traditional means, such as watts/ft{sup 2}, is not a good indicator with the wide range of industrial processes and cleanliness levels occurring in cleanrooms. In this project, metrics allow direct comparison of the efficiency of HVAC systems and components. Energy and flow measurements were taken to determine actual HVAC system energy efficiency. The results confirm a wide variation in operating efficiency and they identify other non-energy operating problems. Improvement opportunities were identified at each of the benchmarked facilities. Analysis of the best performing systems and components is summarized, as are areas for additional investigation.

Tschudi, William; Xu, Tengfang

2001-09-01

141

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

142

The elimination or control of material problems in water heat pipes. Quarterly progress report, No. 3, 1 Jul30 Sep 1974  

Microsoft Academic Search

This study is designed to determine the most effective combination of materials, fabrication methods, and operating procedures for a water heat pipe that will provide satisfactory performance when used as a local absorption, solar-thermal energy collector. Fourteen heat pipes measuring 76 cm long, 2 each from 316 SS, 347 SS, 430 SS, Monel 400, Inconel 600, CDA 715, and Incoloy

Pittinato

1974-01-01

143

Heat Pipe Integrated Microsystems  

SciTech Connect

The trend in commercial electronics packaging to deliver ever smaller component packaging has enabled the development of new highly integrated modules meeting the demands of the next generation nano satellites. At under ten kilograms, these nano satellites will require both a greater density electronics and a melding of satellite structure and function. Better techniques must be developed to remove the subsequent heat generated by the active components required to-meet future computing requirements. Integration of commercially available electronics must be achieved without the increased costs normally associated with current generation multi chip modules. In this paper we present a method of component integration that uses silicon heat pipe technology and advanced flexible laminate circuit board technology to achieve thermal control and satellite structure. The' electronics/heat pipe stack then becomes an integral component of the spacecraft structure. Thermal management on satellites has always been a problem. The shrinking size of electronics and voltage requirements and the accompanying reduction in power dissipation has helped the situation somewhat. Nevertheless, the demands for increased onboard processing power have resulted in an ever increasing power density within the satellite body. With the introduction of nano satellites, small satellites under ten kilograms and under 1000 cubic inches, the area available on which to place hot components for proper heat dissipation has dwindled dramatically. The resulting satellite has become nearly a solid mass of electronics with nowhere to dissipate heat to space. The silicon heat pipe is attached to an aluminum frame using a thermally conductive epoxy or solder preform. The frame serves three purposes. First, the aluminum frame provides a heat conduction path from the edge of the heat pipe to radiators on the surface of the satellite. Secondly, it serves as an attachment point for extended structures attached to the satellite such as solar panels, radiators, antenna and.telescopes (for communications or sensors). Finally, the packages make thermal contact to the surface of the silicon heat pipe through soft thermal pads. Electronic components can be placed on both sides of the flexible circuit interconnect. Silicon heat pipes have a number of advantages over heat pipe constructed from other materials. Silicon heat pipes offer the ability to put the heat pipe structure beneath the active components of a processed silicon wafer. This would be one way of efficiently cooling the heat generated by wafer scale integrated systems. Using this technique, all the functions of a satellite could be reduced to a few silicon wafers. The integration of the heat pipe and the electronics would further reduce the size and weight of the satellite.

Gass, K.; Robertson, P.J.; Shul, R.; Tigges, C.

1999-03-30

144

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

145

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

146

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

147

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

148

CSNI/NRC workshop on ductile piping fracture mechanics: Proceedings. [Includes combined bending and tension stress  

SciTech Connect

This report contains the papers presented at a workshop meeting that was conducted to compare the various different elastic-plastic fracture mechanics analysis methods that can be applied to assess the margin of safety in cracked nuclear plant pipes. A specific problem -- a circumferentially cracked Type 304 stainless steel pipe in combined axial tension and bending -- was addressed. The applied bending moments at crack growth initiation and at fracture instability were sought. Seven estimation type solutions were performed along with a benchmark elastic-plastic finite element solution. It was learned that precise specification of the material stress-strain curve must be made to obtain meaningful results. But, when applied under controlled conditions, the different estimation method solutions do provide reasonably consistent results. These results appear to be conservative in comparison with an elastic-plastic finite element solution that was performed to provide a comparison with these results. Individual papers have been entered into EDB and ERA.

Kanninen, M.F. (comp.)

1988-05-01

149

Heat Pipes  

NASA Technical Reports Server (NTRS)

Heat Pipes were originally developed by NASA and the Los Alamos Scientific Laboratory during the 1960s to dissipate excessive heat build- up in critical areas of spacecraft and maintain even temperatures of satellites. Heat pipes are tubular devices where a working fluid alternately evaporates and condenses, transferring heat from one region of the tube to another. KONA Corporation refined and applied the same technology to solve complex heating requirements of hot runner systems in injection molds. KONA Hot Runner Systems are used throughout the plastics industry for products ranging in size from tiny medical devices to large single cavity automobile bumpers and instrument panels.

1996-01-01

150

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...

151

LASL Benchmark Performance 1978.  

National Technical Information Service (NTIS)

This report presents the results of running several benchmark programs on a CDC STAR-100, a Cray Research CRAY-1, a CDC 6600, a CDC 7600, and a CDC Cyber 73. The benchmark effort included CRAY-1's at several installations running different operating syste...

A. L. McKnight

1979-01-01

152

NAS Parallel Benchmarks.  

National Technical Information Service (NTIS)

The NAS Parallel Benchmarks (NPB) are a suite of parallel computer performance benchmarks. They were originally developed at the NASA Ames Research Center in 1991 to assess high-end parallel supercomputers. Although they are no longer used as widely as th...

D. H. Bailey

2009-01-01

153

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

154

Benchmarking in public procurement  

Microsoft Academic Search

Purpose – This paper investigates the technique of benchmarking to improve the quality of the public procurement process and discusses the importance of benchmarking to overcome perceived weaknesses with these processes. This is followed by a case study of Sri-Lanka, exploring the difficulties faced by public sector employees in separating the daily business of government from the political influences of

Jeanette Raymond

2008-01-01

155

Benchmark Dose Modeling-2  

EPA Science Inventory

The objective of this full-day course is to provide participants with interactive training on the use of the U.S. Environmental Protection Agency’s (EPA) Benchmark Dose Software (BMDS) and its application to risk assessment. Benchmark dose (BMD) modeling involves fitting m...

156

Bag Pipe  

NSDL National Science Digital Library

In this activity, learners explore sound by constructing their very own bagpipe instrument. Learners use PVC pipe, a ziploc bag, rubber tubing, rubber bands, a plastic bottle, and a rubber glove to build their bagpipe. Note: a drill is required, but is not included in the cost of materials.

Workshop, Environmental S.

2011-01-01

157

Benchmark calculations from summarized data: an example  

SciTech Connect

Benchmark calculations often are made from data extracted from publications. Such datamay not be in a formmost appropriate for benchmark analysis, and, as a result, suboptimal and/or non-standard benchmark analyses are often applied. This problem can be mitigated in some cases using Monte Carlo computational methods that allow the likelihood of the published data to be calculated while still using an appropriate benchmark dose (BMD) definition. Such an approach is illustrated herein using data from a study of workers exposed to styrene, in which a hybrid BMD calculation is implemented from dose response data reported only as means and standard deviations of ratios of scores on neuropsychological tests from exposed subjects to corresponding scores from matched controls. The likelihood of the data is computed using a combination of analytic and Monte Carlo integration methods.

Crump, K. S.; Teeguarden, Justin G.

2009-03-01

158

MIDACO software performance on interplanetary trajectory benchmarks  

NASA Astrophysics Data System (ADS)

A numerical study of the MIDACO optimization software on the well known GTOP benchmark set, published by the European Space Agency (ESA), is presented. The GTOP database provides trajectory models of real-world interplanetary space missions such as Cassini, Messenger or Rosetta. The trajectory models are formulated as constrained nonlinear optimization problems and are known to be difficult to solve. Here a comprehensive and rigorous numerical analysis of the MIDACO out-of-the-box performance on the GTOP benchmark set is presented and discussed. In the past, the putative best known solutions of these benchmarks often required several months and even years to be found. In this contribution it will be shown, that MIDACO is able to solve five out of seven of these benchmarks to their best known solution within minutes to hours.

Schlueter, Martin

2014-08-01

159

Electrohydrodynamic heat pipe research  

NASA Technical Reports Server (NTRS)

Experimental and theoretical applications to electrohydrodynamic heat pipe (EHDHP) research are presented. Two problems in the research which are discussed are the prediction of the effective thermal conductance of an EHDHP with threaded grooves for fluid distribution to the evaporator of an EHDHP. Hydrodynamic equations are included along with a discussion of boundary conditions and burn-out conditions. A discussion of the theoretical and experimental results is presented.

Jones, T. B.; Perry, M. P.

1973-01-01

160

Heat Pipe Systems  

NASA Astrophysics Data System (ADS)

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

161

Translational benchmark risk analysis  

PubMed Central

Translational development – in the sense of translating a mature methodology from one area of application to another, evolving area – is discussed for the use of benchmark doses in quantitative risk assessment. Illustrations are presented with traditional applications of the benchmark paradigm in biology and toxicology, and also with risk endpoints that differ from traditional toxicological archetypes. It is seen that the benchmark approach can apply to a diverse spectrum of risk management settings. This suggests a promising future for this important risk-analytic tool. Extensions of the method to a wider variety of applications represent a significant opportunity for enhancing environmental, biomedical, industrial, and socio-economic risk assessments.

Piegorsch, Walter W.

2010-01-01

162

Toxicological Benchmarks for Wildlife  

SciTech Connect

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, food, etc.). While exceedance of these benchmarks does not indicate any particular level or type of risk, concentrations below the benchmarks should not result in significant effects. In practice, when contaminant concentrations in food or water resources are less than these toxicological benchmarks, the contaminants may be excluded from further consideration. However, if the concentration of a contaminant exceeds a benchmark, that contaminant should be retained as a contaminant of potential concern (COPC) and investigated further. The second tier in ecological risk assessment, the baseline ecological risk assessment, may use toxicological benchmarks as part of a weight-of-evidence approach (Suter 1993). Under this approach, based toxicological benchmarks are one of several lines of evidence used to support or refute the presence of ecological effects. Other sources of evidence include media toxicity tests, surveys of biota (abundance and diversity), measures of contaminant body burdens, and biomarkers. This report presents NOAEL- and lowest observed adverse effects level (LOAEL)-based toxicological benchmarks for assessment of effects of 85 chemicals on 9 representative mammalian wildlife species (short-tailed shrew, little brown bat, meadow vole, white-footed mouse, cottontail rabbit, mink, red fox, and whitetail deer) or 11 avian wildlife species (American robin, rough-winged swallow, American woodcock, wild turkey, belted kingfisher, great blue heron, barred owl, barn owl, Cooper's hawk, and red-tailed hawk, osprey) (scientific names for both the mammalian and avian species are presented in Appendix B). [In this document, NOAEL refers to both dose (mg contaminant per kg animal body weight per day) and concentration (mg contaminant per kg of food or L of drinking water)]. The 20 wildlife species were chosen because they are widely distributed and provide a representative range of body sizes and diets. The chemicals are some of those that occur at U.S. Department of Energy (DOE) waste sites. The NOAEL-based benchmarks presented in this report represent values believed to be nonhazardous for the listed wildlife species; LOAEL-based benchmarks represent threshold levels at which adverse effects are likely to become evident. These benchmarks consider contaminant exposure through oral ingestion of contaminated media only. Exposure through inhalation and/or direct dermal exposure are not considered in this report.

Sample, B.E. Opresko, D.M. Suter, G.W.

1993-01-01

163

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

164

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

165

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

166

Benchmark guided wave transmission at an adhered stringer  

NASA Astrophysics Data System (ADS)

A BEM model for plate wave transmission at geometric obstructions is adapted to the 2011 QNDE benchmark problem of guided wave transmission at an adhered stringer. Model adaptation is summarized, and predicted signals are compared to benchmark experimental data. Good agreement is obtained, and is noted to depend on consideration of incident field phase front curvature.

Roberts, R. A.

2012-05-01

167

An enhanced RNA alignment benchmark for sequence alignment programs  

Microsoft Academic Search

BACKGROUND: The performance of alignment programs is traditionally tested on sets of protein sequences, of which a reference alignment is known. Conclusions drawn from such protein benchmarks do not necessarily hold for the RNA alignment problem, as was demonstrated in the first RNA alignment benchmark published so far. For example, the twilight zone – the similarity range where alignment quality

Andreas Wilm; Indra Mainz; Gerhard Steger

2006-01-01

168

Higher Education Ranking and Leagues Tables: Lessons Learned from Benchmarking  

ERIC Educational Resources Information Center

The paper intends to contribute to the debate on ranking and league tables by adopting a critical approach to ranking methodologies from the point of view of a university benchmarking exercise. The absence of a strict benchmarking exercise in the ranking process has been, in the opinion of the author, one of the major problems encountered in the…

Proulx, Roland

2007-01-01

169

Experimental evaluation of the nonlinear seismic response of a nuclear piping system with different support conditions  

Microsoft Academic Search

Nonlinear analysis of nuclear power plant piping systems can be costly, and results can be questionable. However, reserve plastic ductility, evidenced in nonlinear effects, shows high reserve strength and is a very important consideration in design. Efforts are being made within the industry to benchmark analysis and observe nonlinear effects through testing. A series of tests performed on a piping

J. C. Stoessel; P. Ibanez

1983-01-01

170

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

171

Vortex Induced Vibrations in Gapped Restrainted Pipes.  

National Technical Information Service (NTIS)

The vortex induced vibration problem of gapped restrained piping is solved numerically. The model proposed by Skop-Griffin is used to describe the pipe-fluid interaction. The variational formulation is obtained modeling the gapped restraints as non-linear...

P. A. A. Veloso A. F. D. Loula

1984-01-01

172

Generation of synthetic sequential benchmark circuits  

Microsoft Academic Search

Programmable logic architectures increase in capacity before commercial circuits are designed for them, yielding a distinct problem for FPGA vendors: how to test and evaluate the effectiveness of new architectures and software. Benchmark circuits arc a precious commodity, and often cannot be found at the correct granularity, or in the desired quantity. In previous work, we have defined important physical

Michael D. Hutton; Jonathan Rose; Derek G. Corneil

1997-01-01

173

Robot Competitions Ideal Benchmarks for Robotics Research  

Microsoft Academic Search

In this paper, I argue for the use of robotic competitions as benchmarks for robotics research. By providing a common task to be solved at a specific place and a specific time, competitions avoid some of the difficulties arising when evalu- ating robotics research in the own lab. Competitions also bring together multiple research groups working on the same problem.

Sven Behnke

174

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

175

Pipe-to-Pipe Impact Tests.  

National Technical Information Service (NTIS)

The objective of the program is to generate experimental data to evaluate the Nuclear Regulatory Commission's requirements for predicting impact damage. These state that upon impact between two pipes it shall be assumed that the moving pipe will: rupture ...

M. C. C. Bampton J. M. Alzheimer F. A. Simonen

1982-01-01

176

COVE 2A benchmarking calculations using LLUVIA  

SciTech Connect

Benchmarking calculations using the code LLUVIA have been performed in support of the code verification activity (COVE 2A) for the Yucca Mountain Project (YMP). LLUVIA is a program designed for the efficient solution of one-dimensional, steady flow through multiple layers of saturated or partially saturated, fractured, porous media. The benchmarking calculations involve six steady-state and six time-dependent infiltration problems. For the time-dependent analyses, LLUVIA reported only the final steady-state results. This report documents preliminary calculations, resulting code modifications and final calculations for the COVE 2A study. 7 refs., 79 figs., 3 tabs.

Hopkins, P.L.

1990-07-01

177

Use of Fiber Light Pipes with Magnetically Driven Shock Tubes  

Microsoft Academic Search

Glass-fiber light pipes were used to minimize the electrically driven ; shock tube. These pipes eliminated the problem of optical alignment. The ; flexibility of the light pipes permits removal from the shock tube for bakeout ; with a minimum of inconvenience. (B.O.G.);

Eugene Feild; Eldred F. Tubbs

1960-01-01

178

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

179

Task force reduces stuck-pipe costs  

SciTech Connect

A task-force approach to stuck pipe has produced more than a 70% reduction in BP Exploration Operating Co.'s worldwide stuck-pipe costs during 1989 and 1990. We believe that these results have been primarily due to focusing our attention on improving personnel performance rather than to the introduction of new technology. Key elements in this paper of the efforts involved: Recognizing the importance of the drilling contractor and the service company staff's role in helping control stuck pipe; Promoting a rig-team approach to tackling the problem; Providing training on rig-team, stuck-pipe problem solving; and raising awareness of stuck pipe through a coordinated worldwide communications program among BP, contractors, and service companies.

Bradley, W.B. (BP Research, Houston, TX (US)); Jarman, D. (BP Exploration Operation Co., Aberdeen (GB)); Auflick, R.A.; Plott, R.S. (BP Exploration Operating Co., Houston, TX (US)); Wood, R.D. (BP Exploration Operating Co., London (GB)); Schofield, T.R. (BP Exploration Operating Co., Beijing (CN)); Cocking, D. (BP Exploration Operating Co., Ho Chi Minh City (CN))

1991-05-27

180

The Sacred Calf Pipe.  

ERIC Educational Resources Information Center

Tells how the author learned of and recorded the list of Sioux tribe members who have kept the White Buffalo Calf Pipe. Reviews the legend surrounding the origin of the pipe and describes the succession of pipe-keepers and how they inherit the pipe. (Author/AEM)

Simms, Thomas E.

1987-01-01

181

Shield For Flexible Pipe  

NASA Technical Reports Server (NTRS)

Cylindrical shield designed to fit around flexible pipe to protect nearby workers from injury and equipment from damage if pipe ruptures. Designed as pressure-relief device. Absorbs impact of debris ejected radially from broken flexible pipe. Also redirects flow of pressurized fluid escaping from broken pipe onto flow path allowing for relief of pressure while minimizing potential for harm.

Ponton, Michael K.; Williford, Clifford B.; Lagen, Nicholas T.

1995-01-01

182

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

183

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

184

Benchmarking the World's Best  

ERIC Educational Resources Information Center

A century ago, the United States was a world leader in industrial benchmarking. However, after World War II, once no one could compete with the U.S., it became complacent. Many industrialized countries now have higher student achievement and more equitable and efficient education systems. A higher proportion of young people in their workforces…

Tucker, Marc S.

2012-01-01

185

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

186

Scattering of guided waves by circumferential cracks in steel pipes  

Microsoft Academic Search

A novel numerical procedure is presented in this paper to study wave scattering by circumferential cracks in steel pipes. The study is motivated by the need to develop a quantitative ultrasonic technique to characterize properties of cracks in pipes. By employing wave function expansion in axial direction and decomposing the problem into a symmetry problem and an anti-symmetry problem, a

H. Bai; A. H. Shah; N. Popplewell; S. K. Datta

2001-01-01

187

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

188

Magnetic Flux Leakage: a Benchmark Problem  

NASA Astrophysics Data System (ADS)

The magnetic flux leaked by artificial notches machined by EDM is measured for two different rectangular steel plates. The measurements were performed for different field intensities, different liftoffs, and both sides, simultaneously recording the three components of the magnetic field. Attention was paid to the accurate measurement of the liftoff, and to make the magnetic history of the material as predictable as possible. This was achieved by measuring for decreasing magnetic excitations, starting from saturation. The descending branch of the major loop is measured and reported, to allow for a detailed comparison against numerical experiments.

Etcheverry, J. I.; Sánchez, G. A.; Bonadeo, N.

2011-06-01

189

THE MATCHED-FIELD PROCESSING BENCHMARK PROBLEMS  

Microsoft Academic Search

In matched-fleld processing sophisticated acoustic models are combined with signal processing techniques to localize an acoustic source in the ocean. A key challenge has been to develop schemes that work not just in idealized simulations but in realistic scenarios. Additionally it has been di-cult to get a sense of the relative merits of difierent schemes: there has been no common

MICHAEL B. PORTER

190

Benchmarking image fusion system design parameters  

NASA Astrophysics Data System (ADS)

A clear and absolute method for discriminating between image fusion algorithm performances is presented. This method can effectively be used to assist in the design and modeling of image fusion systems. Specifically, it is postulated that quantifying human task performance using image fusion should be benchmarked to whether the fusion algorithm, at a minimum, retained the performance benefit achievable by each independent spectral band being fused. The established benchmark would then clearly represent the threshold that a fusion system should surpass to be considered beneficial to a particular task. A genetic algorithm is employed to characterize the fused system parameters using a Matlab® implementation of NVThermIP as the objective function. By setting the problem up as a mixed-integer constraint optimization problem, one can effectively look backwards through the image acquisition process: optimizing fused system parameters by minimizing the difference between modeled task difficulty measure and the benchmark task difficulty measure. The results of an identification perception experiment are presented, where human observers were asked to identify a standard set of military targets, and used to demonstrate the effectiveness of the benchmarking process.

Howell, Christopher L.

2013-06-01

191

Benchmarking optimization software with performance profiles.  

SciTech Connect

The benchmarking of optimization software has recently gained considerable visibility. Hans Mittlemann's work on a variety of optimization software has frequently uncovered deficiencies in the software and has generally led to software improvements. Although Mittelmann's efforts have gained the most notice, other researchers have been concerned with the evaluation and performance of optimization codes. Recent examples are cited. The interpretation and analysis of the data generated by the benchmarking process are the main technical issues addressed in this paper. Most benchmarking efforts involve tables displaying the performance of each solver on each problem for a set of metrics such as CPU time, number of function evaluations, or iteration counts for algorithms where an iteration implies a comparable amount of work. Failure to display such tables for a small test set would be a gross omission, but they tend to be overwhelming for large test sets. In all cases, the interpretation of the results from these tables is often a source of disagreement. The quantities of data that result from benchmarking with large test sets have spurred researchers to try various tools for analyzing the data. The solver's average or cumulative total for each performance metric over all problems is sometimes used to evaluate performance. As a result, a small number of the most difficult problems can tend to dominate these results, and researchers must take pains to give additional information. In this paper, the authors propose performance profiles -- distribution functions for a performance metric -- as a tool for benchmarking and comparing optimization software. They show that performance profiles combine the best features of other tools for performance evaluation.

Dolan, E. D.; More, J. J.; Mathematics and Computer Science

2002-01-01

192

Evaluation of the protective properties of organic coatings on copper pipes for refrigerator cooling circuit  

Microsoft Academic Search

Copper pipes which are widely used in the refrigerator industry can sometimes work in high humidity atmospheres and in aggressive conditions which can produce dangerous corrosion phenomena of the pipes. Moreover, the design of the refrigerator cooling circuit can introduce some other corrosion problems because copper pipes are frequently in electrical contact with aluminium pipes causing serious galvanic attack on

Lorenzo Fedrizzi; Flavio Deflorian; PierLuigi Bonora

1999-01-01

193

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

194

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

195

Insulated pipe clamp design  

SciTech Connect

Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized.

Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

1980-01-01

196

Flexible ocean upwelling pipe  

DOEpatents

In an ocean thermal energy conversion facility, a cold water riser pipe is releasably supported at its upper end by the hull of the floating facility. The pipe is substantially vertical and has its lower end far below the hull above the ocean floor. The pipe is defined essentially entirely of a material which has a modulus of elasticity substantially less than that of steel, e.g., high density polyethylene, so that the pipe is flexible and compliant to rather than resistant to applied bending moments. The position of the lower end of the pipe relative to the hull is stabilized by a weight suspended below the lower end of the pipe on a flexible line. The pipe, apart from the weight, is positively buoyant. If support of the upper end of the pipe is released, the pipe sinks to the ocean floor, but is not damaged as the length of the line between the pipe and the weight is sufficient to allow the buoyant pipe to come to a stop within the line length after the weight contacts the ocean floor, and thereafter to float submerged above the ocean floor while moored to the ocean floor by the weight. The upper end of the pipe, while supported by the hull, communicates to a sump in the hull in which the water level is maintained below the ambient water level. The sump volume is sufficient to keep the pipe full during heaving of the hull, thereby preventing collapse of the pipe.

Person, Abraham (Los Alamitos, CA)

1980-01-01

197

Benchmark Airport Charges  

NASA Technical Reports Server (NTRS)

The Netherlands Directorate General of Civil Aviation (DGCA) commissioned Hague Consulting Group (HCG) to complete a benchmark study of airport charges at twenty eight airports in Europe and around the world, based on 1996 charges. This study followed previous DGCA research on the topic but included more airports in much more detail. The main purpose of this new benchmark study was to provide insight into the levels and types of airport charges worldwide and into recent changes in airport charge policy and structure, This paper describes the 1996 analysis. It is intended that this work be repeated every year in order to follow developing trends and provide the most up-to-date information possible.

deWit, A.; Cohn, N.

1999-01-01

198

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

199

Benchmarking Modern Web Browsers  

Microsoft Academic Search

Abstract— Many different Web browsers are available on the Internet, free of charge. A browser performs several tasks, such as rendering Web pages on the screen and executing client-side code often embedded,in Web pages. Users typically choose a browser that gives them a satisfying browsing experience, which is partly determined by the speed of the browser. This paper presents benchmark,performance

Jordan Nielson; Carey Williamson; Martin Arlitt

200

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

201

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

202

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

203

Insulation for Piping.  

National Technical Information Service (NTIS)

A foamed insulation for cryogenic pipe lines comprised of a pair of preformed, semicircular foamed insulation half-sections is described. The faying surfaces are coated with a polyurethane adhesive and bonded together about the pipe. The faying surfaces o...

G. Lerma

1975-01-01

204

Flexible Pipe Technology.  

National Technical Information Service (NTIS)

The conference proceedings contain 12 papers. The topics covered are: Technology, products and offshore applications; Steel reinforced elastomer pipes - Design approach and performance characteristics; Flexible pipe installation techniques; Gullfaks ''A''...

1986-01-01

205

Pipe selection guide  

SciTech Connect

Four parameters are used to define a particular pipe: inside diameter, wall thickness, material, and ends. The factors influencing pipe selection are limited to fluid pressure, temperature, chemistry, flow rate, and cost. Other pipe parameters and factors that influence pipe selection and design are mentioned, and, where appropriate, the user is warned that at some stage in the project these factors must be dealt with. It is assumed that the objective is the direct application of geothermal water at temperatures lower than 200/sup 0/F and with 12-in. or smaller pipe. When considering friction losses for sizing purposes, only straight pipe is considered. A discussion of the characteristics and attributes of readily available pipe is included to aid in making a preliminary selection. Energy loss from buried pipe is considered.

Sanders, R.D.

1982-04-01

206

Miniature Heat Pipes.  

National Technical Information Service (NTIS)

Small Business Innovation Research contracts from Goddard Space Flight Center to Thermacore Inc. have fostered the company work on devices tagged 'heat pipes' for space application. To control the extreme temperature ranges in space, heat pipes are import...

1997-01-01

207

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

208

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

209

Comparison of numerical oblique detonation solutions with an asymptotic benchmark  

NASA Technical Reports Server (NTRS)

In order to have confidence in a numerical method, the verification of its reproduction of known benchmark analytic solutions for simple model problems is of great importance. Attention is presently given to a novel benchmarking procedure for numerical models of high speed, reactive 2D flows. The procedure is illustrated by comparing asymptotic and numerical solutions for oblique detonations in which an attached oblique shock is followed by an exothermic reaction with a thick reaction zone.

Grismer, Matthew J.; Powers, Joseph M.

1992-01-01

210

Leaks in pipe networks  

USGS Publications Warehouse

Leak detection in water-distribution systems can be accomplished by solving an inverse problem using measurements of pressure and/or flow. The problem is formulated with equivalent orifice areas of possible leaks as the unknowns. Minimization of the difference between measured and calculated heads produces a solution for the areas. The quality of the result depends on number and location of the measurements. A sensitivity matrix is key to deciding where to make measurements. Both location and magnitude of leaks are sensitive to the quantity and quality of pressure measurements and to how well the pipe friction parameters are known. The overdetermined problem (more measurements than suspected leaks) gives the best results, but some information can be derived from the underdetermined problem. The variance of leak areas, based on the quality of system characteristics and pressure data, indicates the likely accuracy of the results. The method will not substitute for more traditional leak surveys but can serve as a guide and supplement.

Pudar, Ranko, S.; Liggett, James, A.

1992-01-01

211

SPEC CPU2006 benchmark tools  

Microsoft Academic Search

The benchmarks that make up the SPEC CPU2006 benchmark suite are set-up, run, timed, and scored by the CPU tools harness. The tools have evolved over time from a collection of edit-it-yourself makefiles, scripts, and an Excel spreadsheet to the current Perl-based suite. The basic purpose of the tools is to make life easier for the benchmarker; they make it

Cloyce D. Spradling

2007-01-01

212

Image processing benchmark study  

NASA Astrophysics Data System (ADS)

This paper describes the benchmarking of image processing algorithms using high-performance workstations and personal desktop computers. For the various platforms evaluated which included machines from Sun, SGI, Apple, and Gateway, compiler options were varied to obtain the fastest execution times. Algorithms evaluated included typical image processing operations such as derivatives, logical operations, morphology, subtraction, median filter, and the new SKIPSM approach. Data were collected using the different platforms and are presented here in tabular form. The results indicate that the latest generation of personal computers have processing capabilities that are similar to UNIX-based work stations.

Miller, John W. V.; Eddy, C.; Waltz, Frederick M.; Hack, Ralf; Wood, James; Stokes, D.

1998-10-01

213

A benchmark comparison of Monte Carlo particle transport algorithms for binary stochastic mixtures  

Microsoft Academic Search

We numerically investigate the accuracy of two Monte Carlo algorithms originally proposed by Zimmerman [1] and Zimmerman and Adams [2] for particle transport through binary stochastic mixtures. We assess the accuracy of these algorithms using a standard suite of planar geometry incident angular flux benchmark problems and a new suite of interior source benchmark problems. In addition to comparisons of

Patrick S. Brantley

2011-01-01

214

Pipe Line Control  

NASA Technical Reports Server (NTRS)

The array of tanks, pipes and valves in the photo below is a petroleum tank farm in Georgia, part of a petrochemical pipe line system that moves refined petroleum products from Texas and Louisiana to the mid-Eastern seaboard. The same pipes handle a number of different products, such as gasoline, kerosene, jet fuel or fuel oil. The fluids are temporarily stored in tanks, pumped into the pipes in turn and routed to other way stations along the pipe line. The complex job of controlling, measuring and monitoring fuel flow is accomplished automatically by a computerized control and communications system which incorporates multiple space technologies.

1978-01-01

215

Data analysis and laboratory investigation of the behaviour of pipes buried in reactive clay  

Microsoft Academic Search

Buried pipe failures due to ground movement is a common problem which leads to the loss of water or gas supply in urban areas. Statistical analysis of pipe asset data indicates that pipe failure is correlated to ground movement caused by the shrinking and swelling of reactive soils due to seasonal climatic variations. This problem was studied in a large

Derek Chan

216

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

217

Friction Finite Elements Numerical Analysis of Piping Systems: Theory and Applications.  

National Technical Information Service (NTIS)

Contact problems are often encountered in civil engineering applications and specially in nuclear piping systems: pipe whip, impact on supports in case of seismic analysis, non linear calculations of thermal expansions, etc.. Most of the time, the geometr...

A. Millard J. M. Prost A. Ricard

1983-01-01

218

OCTALIS benchmarking: comparison of four watermarking techniques  

NASA Astrophysics Data System (ADS)

In this paper, benchmarking results of watermarking techniques are presented. The benchmark includes evaluation of the watermark robustness and the subjective visual image quality. Four different algorithms are compared, and exhaustively tested. One goal of these tests is to evaluate the feasibility of a Common Functional Model (CFM) developed in the European Project OCTALIS and determine parameters of this model, such as the length of one watermark. This model solves the problem of image trading over an insecure network, such as Internet, and employs hybrid watermarking. Another goal is to evaluate the resistance of the watermarking techniques when subjected to a set of attacks. Results show that the tested techniques do not have the same behavior and that no tested methods has optimal characteristics. A last conclusion is that, as for the evaluation of compression techniques, clear guidelines are necessary to evaluate and compare watermarking techniques.

Piron, Laurent; Arnold, Michael; Kutter, Martin; Funk, Wolfgang; Boucqueau, Jean M.; Craven, Fiona

1999-04-01

219

Benchmarking Bwr Neutron Fluence Calculations  

NASA Astrophysics Data System (ADS)

Calculations of fast neutron fluence to structures in boiling water reactor plant geometries have been performed using two-dimensional transport and a synthesis method. The calculations have been benchmarked using NRC recommended standard benchmarks and using measured data from operating BWR nuclear power plants. Comparisons of the calculations with measurements indicate that the calculations produce fluence estimates with acceptable accuracy.

Lippincott, E. P.; Manahan, M. P.

2003-06-01

220

The benchmarking of airport performance  

Microsoft Academic Search

This paper examines how benchmarking is being used by airport managers as a means of internal performance comparison and improvement. Drawing on interviews with airport managers and a questionnaire survey of the world's top 200 busiest passenger airports, the paper discusses the nature, prevalence and consequences of current benchmarking practices in airports. The authors also include a review of the

Graham Francis; Ian Humphreys; Jackie Fry

2002-01-01

221

Benchmark Dose Modeling - Basic Methdologies  

EPA Science Inventory

Benchmark Dose Modeling – Basic Methodologies Course The objective of this full-day course is to provide participants with interactive training on the use of the U.S. Environmental Protection Agency’s (EPA) Benchmark Dose Software (BMDS) and its application to risk as...

222

Internal Benchmarking for Institutional Effectiveness  

ERIC Educational Resources Information Center

Internal benchmarking is an established practice in business and industry for identifying best in-house practices and disseminating the knowledge about those practices to other groups in the organization. Internal benchmarking can be done with structures, processes, outcomes, or even individuals. In colleges or universities with multicampuses or a…

Ronco, Sharron L.

2012-01-01

223

Handbook for Preparation of Vendor Benchmark Instructions.  

National Technical Information Service (NTIS)

This document suggests the content for benchmark instructions which are used as part of the ADP procurement process. The handbook describes an approach for the benchmark instructions which provides an overview of the benchmark from a management perspectiv...

1976-01-01

224

65. FIRE SUPPRESSION PIPES BEHIND FLAME BUCKET. PIPES TO UMBILICAL ...  

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

65. FIRE SUPPRESSION PIPES BEHIND FLAME BUCKET. PIPES TO UMBILICAL MAST IN LOWER LEFT CORNER; PIPES TO LAUNCHER IN UPPER LEFT CORNER; PIPES TO FLAME BUCKET IN LOWER RIGHT CORNER OF PHOTOGRAPH. POTABLE WATER PIPING IN UPPER RIGHT CORNER OF PHOTO. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

225

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

226

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

227

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

228

Piping Cracks in JPDR, (III)  

Microsoft Academic Search

Failure analysis was made on samples taken from type 304 stainless steel piping systems (core spray, unloading and feed water pipes) that had cracked in service. In the core spray pipe, large cracks including one penetrating through the wall were found in the upper half of the pipe wall, within the heat-affected zone of the weld joint between the pipe

Yutaka OGAWA; Masami SHINDO; Masahiko KIKUCHI

1979-01-01

229

Involvement in plastic pipe  

SciTech Connect

Vested with the responsibility of writing plastic pipe standards, ASTM's Subcommittee D20.17 on Thermoplastic Pipe and Fittings (later reorganized as a full committee, F-17) compiled many of the test methods and standards now accepted by local, state, and federal agencies. One of the most comprehensive piping specifications under F-17's jurisdiction covers gas-pressure piping materials including cellusone acetate butyrate, acrylonitrile butadiene styrene, high- and normal-impact polyvinyl chloride, a variety of polyethylenes, and polybutylene. All of these materials have been used for gas distribution service, some dating back to 1942. As of 1982, figures show that 200,000 miles of all sizes of plastic gas pipe for both gas services and mains have been installed, representing 16.5% of the total gas distribution system in the US. From a handful of early pioneers, the number of utilities using plastic pipe now stands at 933.

Buczala, G.S.; Walker, R.P.

1983-08-01

230

Deployable Heat Pipe Radiator  

NASA Technical Reports Server (NTRS)

A 1.2- by 1.8-m variable conductance heat pipe radiator was designed, built, and tested. The radiator has deployment capability and can passively control Freon-21 fluid loop temperatures under varying loads and environments. It consists of six grooved variable conductance heat pipes attached to a 0.032-in. aluminum panel. Heat is supplied to the radiator via a fluid header or a single-fluid flexible heat pipe header. The heat pipe header is an artery design that has a flexible section capable of bending up to 90 degrees. Radiator loads as high as 850 watts were successfully tested. Over a load variation of 200 watts, the outlet temperature of the Freon-21 fluid varied by 7 F. An alternate control system was also investigated which used a variable conductance heat pipe header attached to the heat pipe radiator panel.

Edelstein, F.

1975-01-01

231

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

232

Abrasion resistant heat pipe  

DOEpatents

A specially constructed heat pipe 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, Donald M. (Leola, PA)

1984-10-23

233

Benchmarking in Academic Pharmacy Departments  

PubMed Central

Benchmarking in academic pharmacy, and recommendations for the potential uses of benchmarking in academic pharmacy departments are discussed in this paper. Benchmarking is the process by which practices, procedures, and performance metrics are compared to an established standard or best practice. Many businesses and industries use benchmarking to compare processes and outcomes, and ultimately plan for improvement. Institutions of higher learning have embraced benchmarking practices to facilitate measuring the quality of their educational and research programs. Benchmarking is used internally as well to justify the allocation of institutional resources or to mediate among competing demands for additional program staff or space. Surveying all chairs of academic pharmacy departments to explore benchmarking issues such as department size and composition, as well as faculty teaching, scholarly, and service productivity, could provide valuable information. To date, attempts to gather this data have had limited success. We believe this information is potentially important, urge that efforts to gather it should be continued, and offer suggestions to achieve full participation.

Chisholm-Burns, Marie; Nappi, Jean; Gubbins, Paul O.; Ross, Leigh Ann

2010-01-01

234

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

235

The optimal shape of a pipe  

NASA Astrophysics Data System (ADS)

In shape optimization, recently the question arose, whether or not the cylindrical pipe has the optimal shape for the transport of an incompressible fluid. In this short note, a proof will be presented that a cylindrical pipe with Poiseuille's flow inside indeed is optimal for the transportation of an incompressible fluid under the criterion "energy dissipated by the fluid." The proof reduces the problem to the minimization of a two-dimensional Dirichlet's integral. This simpler problem can be solved with a symmetrization argument.

Schulz, Andreas

2013-08-01

236

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

237

MHD Benchmarking of Desktop Machines  

NASA Astrophysics Data System (ADS)

For code development, parameter space surveys, and code debugging, dedicated use of a fast, single processor machine is often better than shared, queued use of a supercomputer. Although there are many benchmark results available, most deal with the most common use of single processor machines (e.g. web, entertainment, and business applications) to arrive at a large variance of rankings. To best determine what machines would serve a small MHD group such as ours at ASIAA, we needed MHD benchmark results. Here we present results from a few benchmark tests for running MHD Zeus 2D codes on a variety of platforms of PCs and Sun Workstations.

Allen, A.; Chou, M.; Shang, H.

238

A Heterogeneous Medium Analytical Benchmark  

SciTech Connect

A benchmark, called benchmark BLUE, has been developed for one-group neutral particle (neutron or photon) transport in a one-dimensional sub-critical heterogeneous plane parallel medium with surface illumination. General anisotropic scattering is accommodated through the Green's Function Method (GFM). Numerical Fourier transform inversion is used to generate the required Green's functions which are kernels to coupled integral equations that give the exiting angular fluxes. The interior scalar flux is then obtained through quadrature. A compound iterative procedure for quadrature order and slab surface source convergence provides highly accurate benchmark qualities (4- to 5- places of accuracy) results.

Ganapol, B.D.

1999-09-27

239

Reference Piping Design Stress Analysis.  

National Technical Information Service (NTIS)

A history of the piping stress analysis is presented, tracing the work done from the conceptual stage to the final reference design layout. The piping stress analysis of the final reference design piping layout is also presented.

S. Mathias S. Westerman

1973-01-01

240

Smoke Production of Nonmetallic Pipes.  

National Technical Information Service (NTIS)

The smoke production of nonmetallic pipes was investigated using 'Test Method for Specific Optical Density of Smoke Generated by Solid Materials,' ASTM E 662. The pipe samples consisted of two epoxy resin glass reinforced pipes, two vinyl ester resin glas...

W. H. McLain L. Nash

1995-01-01

241

Benchmarking unstructured systems  

SciTech Connect

Systems developed without the advantage of structured techniques can currently be found, even though most managers agree that the lack of such techniques is apt to produce an inferior product. When an unstructured system is identified, management must decide if it should be rewritten according to modern standards. The case study presented here describes how management in one Data Processing shop made that decision and learned something about their perceptions of the staff as well. To be judged successful, a system should be friendly, useful and easily maintainable. Research has shown that psychologically complex programs are more expensive to maintain than those developed with structured techniques, free from such complexity. In this study, three suspect systems were statistically measured against a base system. When a suspect system proved at least as psychologically complex as the base system, future maintenance costs were assumed to be at least as high as for the benchmark system. In addition to judging whether or not a system should be rewritten to provide ease of maintenance, the study provided management with a more accurate view of programmer work habits. Programmers previously judged to be extremely competent had created a high level of psychological complexity which is expected to result in high maintenance costs when other programmers become responsible for the system.

Brice, L.; Connell, J.; Lockhart, G.

1983-01-01

242

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

243

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

244

NASA Software Engineering Benchmarking Study.  

National Technical Information Service (NTIS)

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. Th...

H. L. Rarick J. C. Kelly J. M. Wifl R. T. Crumbley S. H. Godfrey

2013-01-01

245

The heat pipe  

Microsoft Academic Search

The heat pipe is a device having a high thermal conductance which utilizes the transport of a vapour and rejection of latent heat to achieve efficient thermal energy transport. The theory of heat pipes is well developed. Their use in applications involving temperatures in the cryogenic regime, and with development units running as high as 2000 degrees C, shows that

P. D. Dunn; D. A. Reay

1973-01-01

246

Loop heat pipes  

Microsoft Academic Search

Loop heat pipes (LHPs) are two-phase heat-transfer devices with capillary pumping of a working fluid. They possess all the main advantages of conventional heat pipes, but owing to the original design and special properties of the capillary structure are capable of transferring heat efficiency for distances up to several meters at any orientation in the gravity field, or to several

Yu. F. Maydanik

2005-01-01

247

Heat pipe technology issues  

SciTech Connect

Critical high temperature, high power applications in space nuclear power designs are near the current state of the art of heat pipe technology in terms of power density, operating temperature, and lifetime. Recent heat pipe development work at Los Alamos National Laboratory has involved performance testing of typical space reactor heat pipe designs to power levels in excess of 19 kW/cm/sup 2/ axially and 300 W/cm/sup 2/ radially at temperatures in the 1400 to 1500 K range. Operation at conditions in the 10 kW/cm/sup 2/ range has been sustained for periods of up to 1000 hours without evidence of performance degradation. The effective length for heat transport in these heat pipes was from 1.0 to 1.5 M. Materials used were molybdenum alloys with lithium employed as the heat pipe operating fluid. Shorter, somewhat lower power, molybdenum heat pipes have been life tested at Los Alamos for periods of greater than 25,000 hours at 1700 K with lithium and 20,000 hours at 1500/sup 0/K with sodium. These life test demonstrations and the attendant performance limit investigations provide an experimental basis for heat pipe application in space reactor design and represent the current state-of-the-art of high temperature heat pipe technology.

Merrigan, M.A.

1984-04-01

248

Apparatus for cleaning pipe  

SciTech Connect

This patent describes an apparatus for cleaning pipe having a pipe interior, the apparatus comprising: a rigid, longitudinally extending stem; a motor stationarily mounted on the stem; an outer body which surrounds the motor; drive means for connecting the motor to the outer body; a power coupling connected to the stem for supplying power to the motor.

Allison, A.; Tarsha, S.; McMillan, J.S.

1992-02-25

249

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

250

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

251

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

252

Memory-Intensive Benchmarks: IRAM vs. Cache-Based Machines  

NASA Technical Reports Server (NTRS)

The increasing gap between processor and memory performance has lead 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 control structures, and the ratio of computation to memory operation.

Biswas, Rupak; Gaeke, Brian R.; Husbands, Parry; Li, Xiaoye S.; Oliker, Leonid; Yelick, Katherine A.; Biegel, Bryan (Technical Monitor)

2002-01-01

253

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

254

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

255

Pipe wiper system  

SciTech Connect

This patent describes improvement in a pipe wiper assembly for stripping fluid from the outer surface of a well string. The assembly comprises: a container having side walls, a pair of pipe wiper blades situated within the container and movable between an open position, wherein they are disassociated from the well string, and a closed position, wherein they are pressed against the well string. The improvement comprises: a frame situated within the container, for limited horizontal movement therein, having a horizontal guideway to accept the pipe wiper blades for movement from opposite sides of the well string between the open and the closed positions; a pair of fluid power cylinder assemblies for each of the pipe wiper blades, mounted on the frame, arranged for linking the frame and the pipe wiper blade for movement between the open and the closed positions; and flexible means, connected to the fluid power cylinder assembly, for supplying fluid power thereto.

Reddock, J.A.

1991-01-08

256

Extendable pipe crawler  

DOEpatents

A pipe crawler is described having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by inchworm'-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward. 5 figures.

Hapstack, M.

1991-05-28

257

Research on computer systems benchmarking  

NASA Technical Reports Server (NTRS)

This grant addresses the topic of research on computer systems benchmarking and is more generally concerned with performance issues in computer systems. This report reviews work in those areas during the period of NASA support under this grant. The bulk of the work performed concerned benchmarking and analysis of CPUs, compilers, caches, and benchmark programs. The first part of this work concerned the issue of benchmark performance prediction. A new approach to benchmarking and machine characterization was reported, using a machine characterizer that measures the performance of a given system in terms of a Fortran abstract machine. Another report focused on analyzing compiler performance. The performance impact of optimization in the context of our methodology for CPU performance characterization was based on the abstract machine model. Benchmark programs are analyzed in another paper. A machine-independent model of program execution was developed to characterize both machine performance and program execution. By merging these machine and program characterizations, execution time can be estimated for arbitrary machine/program combinations. The work was continued into the domain of parallel and vector machines, including the issue of caches in vector processors and multiprocessors. All of the afore-mentioned accomplishments are more specifically summarized in this report, as well as those smaller in magnitude supported by this grant.

Smith, Alan Jay (Principal Investigator)

1996-01-01

258

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

259

RASSP benchmark 1 technical description. Revision 1  

NASA Astrophysics Data System (ADS)

This report describes the first in a series of application problems which are intended to measure the performance of a process for rapid prototyping of embedded digital signal processors. The rapid prototyping process is being developed for the ARPA/Tri-Services Rapid Prototyping of Application Specific Signal Processors (RASSP) program. The first application problem is to develop a virtual prototype for a real time digital signal processor capable of forming images from high resolution synthetic aperture radar data. Details of the application are provided along with design constraints and optimization requirements for the processor. The report also describes product and process metrics which are to be collected to derive measures of process and product performance. The application problem and associated performance metrics comprise what is termed a benchmark technical description.

Zuerndorfer, B. W.; Anderson, J. C.; Ford, R. A.; Anderson, A. H.; Rocco, G. A.

1995-01-01

260

Real-parameter optimization performance study on the CEC2005 benchmark with SPC-PNX  

Microsoft Academic Search

This paper presents a performance study of a real-parameter genetic algorithm (SPC-PNX) on a new benchmark of real-parameter optimisation problems. This benchmark provides a systematic way to compare different optimisation methods on exactly the same test problems. These problems were designed to be hard as they incorporate features that have been shown to pose great difficulty to many optimisation methods

Pedro J. Ballester; John Stephenson; Jonathan N. Carter; Kerry Gallagher

2005-01-01

261

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

262

Development of magnetic flux leakage pipe inspection robot using Hall sensors  

Microsoft Academic Search

Pipeline safety evaluation is an important problem of industry, and this paper presents an automated pipe inspection robot to inspect pipeline defects. Based on magnetic flux leakage (MFL) method, the robot utilizes established mechatronic principles to produce a low-cost device capable of detecting inner pipe defects. The pipe inspection robot's design mainly includes its mechanical design, electronic design and data

Jin Tao; Que Peiwen; Tao Zhengsu

2004-01-01

263

High-level Vibration and Noise Analysis of Nuclear Pipes with Orifice  

Microsoft Academic Search

Vibration caused structure failure is a common occurrence in industry piping. In the design process of nuclear piping, fluid-induced vibration effect is normally not taken into account because of the lack of practical guidance and regulatory requirements. Nuclear pipes suffering from high-level vibration and noise problems have been studied in this paper. Field investigation and vibration measurement provide basic information

MAO Qing; ZHANG Yixiong; XIANG Wenyuan; BI Qincheng; LI Huixiong; ZANG Fenggang

264

Verification and benchmark testing of the NUFT computer code  

Microsoft Academic Search

This interim report presents results of work completed in the ongoing verification and benchmark testing of the NUFT (Nonisothermal Unsaturated-saturated Flow and Transport) computer code. NUFT is a suite of multiphase, multicomponent models for numerical solution of thermal and isothermal flow and transport in porous media, with application to subsurface contaminant transport problems. The code simulates the coupled transport of

K. H. Lee; J. J. Nitao; A. Kulshrestha

1993-01-01

265

Gas pipe explorer robot  

NASA Technical Reports Server (NTRS)

A gas pipe explorer formed of a plurality of connecting elements, and an articulation element between the connected elements. The connected elements include drive capabilities, and the articulation element allows the connected elements to traverse gas pipes of arbitrary shapes and sizes. A sensor may sends the characteristics of the gas pipe, and the communication element may send back those sends characteristics. The communication can be wired, over a tether connecting the device to a remote end. Alternatively, the connection can be wireless, driven by either a generator or a battery.

Wilcox, Brian (Inventor)

2004-01-01

266

T-Junction Benchmark  

SciTech Connect

Part 1: Two different volume renderings of fluid temperatures in a turbulent T-junction mixing problem at Reynolds number Re=40,000. Part 2: Volume rendering of fluid temperatures in a turbulent T-junction mixing problem at Reynolds number Re=40,000, simulated using Nek5000 at three different resolutions. Part 3: Temperature distribution for a turbulent T-junction mixing problem at Reynolds number Re=40,000, simulated using Nek5000 with 89056 spectral elements of order N=9 (65 million grid points). Credits: Science: Aleks Obabko and Paul Fisher, Argonne National Laboratory? Visualization: Hank Childs, Lawrence Berkeley National Laboratory?? This research used resources of the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under contract DE-AC02-06CH11357

None

2010-01-01

267

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

268

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

269

Experimenting with a "Pipe" Whistle  

ERIC Educational Resources Information Center

A simple pipe whistle can be made using pieces of PVC pipe. The whistle can be used to measure the resonant frequencies of open or closed pipes. A slightly modified version of the device can be used to also investigate the interesting dependence of the sound frequencies produced on the orifice-to-edge distance. The pipe whistle described here…

Stafford, Olga

2012-01-01

270

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

271

Penalty adapting ant algorithm: application to pipe network optimization  

NASA Astrophysics Data System (ADS)

A penalty adapting ant algorithm is presented in an attempt to eliminate the dependency of ant algorithms on the penalty parameter used for the solution of constrained optimization problems. The method uses an adapting mechanism for determination of the penalty parameter leading to elimination of the costly process of penalty parameter tuning. The method is devised on the basis of observation that for large penalty parameters, infeasible solutions will have a higher total cost than feasible solutions and vice versa. The method therefore uses the best feasible and infeasible solution costs of the iteration to adaptively adjust the penalty parameter to be used in the next iteration. The pheromone updating procedure of the max-min ant system is also modified to keep ants on and around the boundary of the feasible search space where quality solutions can be found. The sensitivity of the proposed method to the initial value of the penalty parameter is investigated and indicates that the method converges to optimal or near-optimal solutions irrespective of the initial starting value of the penalty parameter. This is significant as it eliminates the need for sensitivity analysis of the method with respect to the penalty factor, thus adding to the computational efficiency of ant algorithms. Furthermore, it is shown that the success rate of the search algorithm in locating an optimal solution is increased when a self-adapting mechanism is used. The presented method is applied to a benchmark pipe network optimization problem in the literature and the results are presented and compared with those of existing algorithms.

Afshar, M. H.

2008-10-01

272

An electrohydrodynamic heat pipe  

NASA Technical Reports Server (NTRS)

Dielectric liquid for transfer of heat provides liquid flow from the condenser section to the evaporator section in conventional heat pipes. Working fluid is guided or pumped by an array of wire electrodes connected to a high-voltage source.

Jones, T. B.

1972-01-01

273

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

274

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

275

Impregnation of Concrete Pipe.  

National Technical Information Service (NTIS)

The program was undertaken to investigate methods to increase the corrosion resistance, increase the strength, and reduce the permeability of concrete used in sewer line applications by impregnating the concrete pipe with relatively low cost resins such a...

1971-01-01

276

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

277

Deformation of metal pipe due to underwater shock wave  

SciTech Connect

The deformation process of the metal pipes, accelerated by underwater shock wave resulting from the underwater detonation of explosive inside the metal pipe, was investigated by means of both the optical observation experiment and the numerical calculation. The expanding deformation of metal pipes was experimentally viewed by both framing and streak photographic means. A computer code based on the arbitrary Lagrangian and Eulerian (ALE) method was used to perform the numerical simulation on this problem. It has confirmed that the deformations of the metal pipes obtained from the streak photographs agree quite well with those obtained by the numerical calculation. The experimental and numerical results both show that the expanding velocity along the radial direction in aluminum pipe is larger than that in copper pipe, under the same loading conditions: and also, the time needed to reach the maximum radial velocity is shorter in aluminum pipe than in copper pipe. The calculations clearly indicate that the metal pipes are able to acquire a maximum expanding velocity along the radial direction in a very short time after the beginning of the action of underwater shock wave, and also this maximum velocity value only decreases a little in the later time period.

Itoh, S.; Kira, A.; Liu, Z.Y.; Nagano, S. [Kumamoto Univ. (Japan). Dept. of Mechanical Engineering and Materials Science

1999-05-01

278

Freezable heat pipe  

DOEpatents

A heat pipe whose fluid can be repeatedly frozen and thawed without damage to the casing. An additional part is added to a conventional heat pipe. This addition is a simple porous structure, such as a cylinder, self-supporting and free standing, which is dimensioned with its diameter not spanning the inside transverse dimension of the casing, and with its length surpassing the depth of maximum liquid.

Ernst, Donald M. (Leola, PA); Sanzi, James L. (Lancaster, PA)

1981-02-03

279

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

280

A comparison and benchmark of two electron cloud packages  

Microsoft Academic Search

We present results from precision simulations of the electron cloud (EC) problem in the Fermilab Main Injector using two distinct codes. These two codes are (i)POSINST, a F90 2D+ code, and (ii)VORPAL, a 2D\\/3D electrostatic and electromagnetic code used for self-consistent simulations of plasma and particle beam problems. A specific benchmark has been designed to demonstrate the strengths of both

Paul L. G. Lebrun; James F. Amundson; Panagiotis G. Spentzouris; Seth A. Veitzer

2012-01-01

281

Robust Extraction of Tomographic Information via Randomized Benchmarking  

NASA Astrophysics Data System (ADS)

We describe how randomized benchmarking can be used to reconstruct the unital part of any trace-preserving quantum map, which in turn is sufficient for the full characterization of any unitary evolution or, more generally, any unital trace-preserving evolution. This approach inherits randomized benchmarking's robustness to preparation, measurement, and gate imperfections, thereby avoiding systematic errors caused by these imperfections. We also extend these techniques to efficiently estimate the average fidelity of a quantum map to unitary maps outside of the Clifford group. The unitaries we consider correspond to large circuits commonly used as building blocks to achieve scalable, universal, and fault-tolerant quantum computation. Hence, we can efficiently verify all such subcomponents of a circuit-based universal quantum computer. In addition, we rigorously bound the time and sampling complexities of randomized benchmarking procedures, proving that the required nonlinear estimation problem can be solved efficiently.

Kimmel, Shelby; da Silva, Marcus P.; Ryan, Colm A.; Johnson, Blake R.; Ohki, Thomas

2014-01-01

282

Benchmarking variable cost performance in an industrial power plant  

SciTech Connect

One of the most perplexing problems for industrial power plants committed to improving competitiveness is measuring variable cost performance over time. Because variable costs like fuel and electricity represent the overwhelming majority of power plant expenses, it is imperative to develop and deploy a tool that can help plants benchmark operating performance. This article introduces a benchmarking methodology designed to meet this need. The energy conversion index (ECI) ratios the value of utilities exported from the power plant to the actual cost of the fuel and electricity required to produce them, generating a single number or index. Variable cost performance is benchmarked by comparing the index from one period of time to the index of another comparable period of time. Savings (or costs) attributable to excellent (or poor) performance can easily be calculated by using the former period`s index to project the current period`s cost.

Kane, J.F. Jr.; Bailey, W.F. [E.I. du Pont de Nemours and Co., Inc., Charlotte, NC (United States)

1999-04-01

283

Reducing stress in contained pipes  

SciTech Connect

Increasingly, chemical-process-industries plants are conveying fluids in contained pipes. These pipes inside pipes improve operational and environmental safety by keeping leaks from escaping into the plant, if the pipes are indoors, or into the soil, air or water if they are outdoors. Du Pont recently installed two contained-piping systems in one of its Wilmington, Del., facilities. The lines are made from fiberglass-reinforced vinyl ester, with 3-in.-dia. carrier pipes and 6-in.-dia. containment pipes. Heat from flowing liquid makes the carrier pipes expand, which causes them to move laterally inside the containment pipe. When flow stops, the temperature drops and the carrier pipes contract. To limit carrier-pipe movement, DuPont planned to install donut-shaped support at the ends of straight-run sections. However, a computerized analysis found that the supports cause high stress in the carrier pipes. The paper describes the solution that Du Pont found to reduce the stress on the piping and prolong the service life of the pipes.

Not Available

1993-07-01

284

Benchmarking: Achieving the best in class.  

National Technical Information Service (NTIS)

Oftentimes, people find the process of organizational benchmarking an onerous task, or, because they do not fully understand the nature of the process, end up with results that are less than stellar. This paper presents the challenges of benchmarking and ...

L. Kaemmerer

1996-01-01

285

The Impact Hydrocode Benchmark and Validation Project  

Microsoft Academic Search

When properly benchmarked and validated against observations computer models offer a powerful tool for understanding the mechanics of impact crater formation. We present results from a project to benchmark and validate shock physics codes.

E. Pierazzo; N. Artemieva; E. Asphaug; E. C. Baldwin; J. Cazamias; R. Coker; G. S. Collins; D. A. Crawford; T. Davison; D. Elbeshausen; K. A. Holsapple; K. R. Housen; D. G. Korycansky; K. Wünnemann

2008-01-01

286

VVER-440 dosimetry and neutron spectrum benchmark.  

National Technical Information Service (NTIS)

Light Water Reactor (LWR) benchmark experiments performed in the United States under the Surveillance Dosimetry Improvement Program (SDIP), in general, reported measured reaction rates and not neutron flux spectrum. The VVER-440 benchmark experiments, usi...

E. Sajot F. B. K. Kam

1993-01-01

287

Neutronics benchmark experiment on tungsten  

Microsoft Academic Search

In order to validate neutron cross sections for W, a benchmark experiment was carried out at the Frascati Neutron Generator (FNG), that consisted of the irradiation with 14 MeV neutrons of a tungsten block. Neutron flux and gamma heating were measured inside the block. The results were analysed with the Monte Carlo code MCNP-4C using for W, Fe and Ni

P. Batistoni; M. Angelone; L. Petrizzi; M. Pillon

2004-01-01

288

Benchmarking Multipacting Simulations in VORPAL  

Microsoft Academic Search

We will present the results of benchmarking simulations run to test the ability of VORPAL to model multipacting processes in Superconducting Radio Frequency structures. VORPAL is an electromagnetic (FDTD) particle-in-cell simulation code originally developed for applications in plasma and beam physics. The addition of conformal boundaries and algorithms for secondary electron emission allow VORPAL to be applied to multipacting processes.

C. Nieter; C. Roark; P. Stoltz; K. Tian

2009-01-01

289

Science Grades K-4 Benchmarks.  

ERIC Educational Resources Information Center

This document explains the Arkansas science benchmarks for grades K-4 which were developed to provide guidance to science teachers. The content standards for three strands--physical science systems, life science systems, and Earth science/space science systems--were identified based on grade levels. (YDS)

Arkansas State Dept. of Education, Little Rock.

290

Using Benchmarks to Compare Fractions  

NSDL National Science Digital Library

This task is intended primarily for instruction purposes. The goal is to provide examples for comparing two fractions. This is an important method for comparing fractions and one which requires a strong number sense and ability to make mental calculations. It is, however, a difficult ability to assess because the method is only appropriate when there is a clear benchmark fraction to be used.

IInstitute for Mathematics & Education funded by the Bill & Melinda Gates Foundation

2012-08-01

291

CALOR89: Calorimetry analysis and benchmarking  

SciTech Connect

The CALOR89 code system has been utilized for extensive calorimeter benchmarking and design calculations. Even though this code system has previously demonstrated its power in the design of calorimeters, major revisions in the form of better collision models and cross-section data bases have expanded its capabilities. The benchmarking has been done with respect to the ZEUS and DO calorimeters. For the most part, good agreement with experimental data has been obtained. The design calculations presented here were done for a variety of absorbers (depleted uranium, lead, and iron) of various thickness, for a given scintillator thickness and for a fixed absorber thickness using various thickness for the scintillator. These studies indicate that a compensating calorimeter can be built using depleted uranium or lead as the absorber, whereas a purely iron calorimeter would be non-compensating. One possibly major problem exists with the depleted uranium calorimeter due to the large number of neutrons produced and due to the large capture cross-section of uranium. These captured neutrons will produce a signal in the scintillator due to secondary gamma rays for many hundreds of nanoseconds and this may contribute substantially to background noise and pile up. 14 figs.

Gabriel, T.A.; Alsmiller, R.G. Jr.; Bishop, B.L.; Fu, C.Y. (Oak Ridge National Lab., TN (USA)); Handler, T. (Tennessee Univ., Knoxville, TN (USA)); Panakkal, J.K.; Proudfoot, J. (Argonne National Lab., IL (USA)); Cremaldi, L.; Moore, B.; Reidy, J.J. (Mississippi Univ., University, MS (USA))

1990-01-01

292

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

293

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

294

Analysis of the delay hot\\/cold water problem  

Microsoft Academic Search

We have analysed the delay hot\\/cold water problem in a fluid-pipe system. Our simplified model has been used to evaluate variations of pipe and fluid temperatures with time at different locations when the fluid-pipe system is subjected to a sudden increase in fluid temperature at the pipe entrance. The analysis shows a slow increase in pipe temperature with time and

Namir Saman; Hashim Mahdi

1996-01-01

295

Benchmarking ENDF\\/B-VII.0  

Microsoft Academic Search

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

Steven C. van der Marck; Steven C. van der

2006-01-01

296

Benchmarking ENDF\\/B-VII.0  

Microsoft Academic Search

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

Steven C. van der Marck

2006-01-01

297

Benchmarking ETL Workflows  

NASA Astrophysics Data System (ADS)

Extraction-Transform-Load (ETL) processes comprise complex data workflows, which are responsible for the maintenance of a Data Warehouse. A plethora of ETL tools is currently available constituting a multi-million dollar market. Each ETL tool uses its own technique for the design and implementation of an ETL workflow, making the task of assessing ETL tools extremely difficult. In this paper, we identify common characteristics of ETL workflows in an effort of proposing a unified evaluation method for ETL. We also identify the main points of interest in designing, implementing, and maintaining ETL workflows. Finally, we propose a principled organization of test suites based on the TPC-H schema for the problem of experimenting with ETL workflows.

Simitsis, Alkis; Vassiliadis, Panos; Dayal, Umeshwar; Karagiannis, Anastasios; Tziovara, Vasiliki

298

Benchmarking: Achieving the best in class  

SciTech Connect

Oftentimes, people find the process of organizational benchmarking an onerous task, or, because they do not fully understand the nature of the process, end up with results that are less than stellar. This paper presents the challenges of benchmarking and reasons why benchmarking can benefit an organization in today`s economy.

Kaemmerer, L

1996-05-01

299

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

300

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

301

Autopilot: A Platform for System Software Benchmarking  

Microsoft Academic Search

When developing software, it is essential to evaluate its performance and stability, making benchmarking an es- sential and significant part of the software development cycle. Benchmarking is also used to show that a sys- tem is useful or provide insight into how systems be- have. However, benchmarking is a tedious task that few enjoy, but every programmer or systems researcher

Charles P. Wright; Nikolai Joukov; Devaki Kulkarni; Yevgeniy Miretskiy; Erez Zadok

2005-01-01

302

Performance Benchmarking of Australian Business Regulation  

Microsoft Academic Search

The Productivity Commission’s research report into ‘Performance Benchmarking of Australian Business Regulation’ was released in March 2007. The Australian Government asked the Commission to develop a framework to benchmark regulatory regimes and their cost burdens across all levels of government for stage 1 of a two-stage study. The Commission found that benchmarking regulatory compliance burdens across all jurisdictions in Australia

303

lmbench: an extensible micro-benchmark suite  

Microsoft Academic Search

SUMMARY lmbench is a powerful and extensible suite of micro-benchmarks that measures a variety of important aspects of system performance. It has a powerful timing harness that manages most of the 'housekeeping' chores associated with benchmarking, making it easy to create new benchmarks that analyze systems or components of specific interest to the user. In many ways lmbench is a

Carl Staelin

2005-01-01

304

Explosive Welding of Pipes  

NASA Astrophysics Data System (ADS)

For connection by welding it is suggested to use the explosive welding method. This method is rather new. Nevertheless, it has become commonly used among the technological developments. This method can be advantageous (saving material and physical resources) comparing to its statical analogs (electron-beam welding, argon-arc welding, plasma welding, gas welding, etc.), in particular, in hard-to-reach areas due to their geographic and climatic conditions. The suggestion is to use water as filler. The principle of non-compressibility of liquid under quasi-dynamic loading is used. In one-dimensional gasdynamic and elastic-plastic calculations we determined non-deformed mass of water (perturbations, which are moving in the axial direction with sound velocity, should not reach the layer end boundaries for 5-7 circulations of shock waves in the radial direction). Linear dimension of the water layer from the zone of pipe coupling along axis in each direction is >= 2R, where R is the internal radius of pipe. Model experiments with pipes having radii R = 57 mm confirmed results of the calculations and the possibility in principle to weld pipes by explosion with use of water as filler. Reduction of pipe diameter after dynamic loading and explosive welding was ˜2%.

Burtseva, Olga

2007-06-01

305

Pipe Clamp Effects on Thin-Walled Pipe Design.  

National Technical Information Service (NTIS)

Clamp induced stresses in FFTF piping are sufficiently large to require structural assessment. The basic principles and procedures used in analyzing FFTF piping at clamp support locations for compliance with ASME Code rules are given. Typical results from...

M. R. Lindquist

1980-01-01

306

Benchmarking Gas Path Diagnostic Methods: A Public Approach  

NASA Technical Reports Server (NTRS)

Recent technology reviews have identified the need for objective assessments of engine health management (EHM) technology. The need is two-fold: technology developers require relevant data and problems to design and validate new algorithms and techniques while engine system integrators and operators need practical tools to direct development and then evaluate the effectiveness of proposed solutions. This paper presents a publicly available gas path diagnostic benchmark problem that has been developed by the Propulsion and Power Systems Panel of The Technical Cooperation Program (TTCP) to help address these needs. The problem is coded in MATLAB (The MathWorks, Inc.) and coupled with a non-linear turbofan engine simulation to produce "snap-shot" measurements, with relevant noise levels, as if collected from a fleet of engines over their lifetime of use. Each engine within the fleet will experience unique operating and deterioration profiles, and may encounter randomly occurring relevant gas path faults including sensor, actuator and component faults. The challenge to the EHM community is to develop gas path diagnostic algorithms to reliably perform fault detection and isolation. An example solution to the benchmark problem is provided along with associated evaluation metrics. A plan is presented to disseminate this benchmark problem to the engine health management technical community and invite technology solutions.

Simon, Donald L.; Bird, Jeff; Davison, Craig; Volponi, Al; Iverson, R. Eugene

2008-01-01

307

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

308

Allowable Cover on Corrugated Steel Pipe.  

National Technical Information Service (NTIS)

The objective of the research project was to develop tables of allowable heights of cover for various sizes of prefabricated corrugated steel pipe, pipe arches and field assembled corrugated steel structural plate pipe and pipe arches. Ring compression th...

K. M. Fenwick

1969-01-01

309

Composite drill pipe  

DOEpatents

A composite pipe segment is formed to include tapered in wall thickness ends that are each defined by opposed frustoconical surfaces conformed for self centering receipt and intimate bonding contact within an annular space between corresponding surfaces of a coaxially nested set of metal end pieces. The distal peripheries of the nested end pieces are then welded to each other and the sandwiched and bonded portions are radially pinned. The composite segment may include imbedded conductive leads and the axial end portions of the end pieces are shaped to form a threaded joint with the next pipe assembly that includes a contact ring in one pipe assembly pierced by a pointed contact in the other to connect the corresponding leads across the joint.

Leslie, James C. (Fountain Valley, CA); Leslie, II, James C. (Mission Viejo, CA); Heard, James (Huntington Beach, CA); Truong, Liem (Anaheim, CA), Josephson; Marvin (Huntington Beach, CA), Neubert; Hans (Anaheim, CA)

2008-12-02

310

Heat Pipe Technology  

NASA Technical Reports Server (NTRS)

The heat pipe, a sealed chamber whose walls are lined with a "wick," a thin capillary network containing a working fluid in liquid form was developed for a heat distribution system for non-rotating satellites. Use of the heat pipe provides a continuous heat transfer mechanism. "Heat tubes" that improve temperature control in plastics manufacturing equipment incorporated the heat pipe technology. James M. Stewart, an independent consultant, patented the heat tubes he developed and granted a license to Kona Corporation. The Kona Nozzle for heaterless injection molding gets heat for its operation from an external source and has no internal heating bands, reducing machine maintenance and also eliminating electrical hazards associated with heater bands. The nozzles are used by Eastman Kodak, Bic Pen Corporation, Polaroid, Tupperware, Ford Motor Company, RCA, and Western Electric in the molding of their products.

1981-01-01

311

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

312

Apparatus for inspecting piping  

DOEpatents

An inspection rabbit for inspecting piping systems having severe bends therein. The rabbit consists of a flexible, modular body containing a miniaturized eddy current inspection probe, a self-contained power supply for proper operation of the rabbit, an outer surface that allows ease of movement through piping systems and means for transmitting data generated by the inspection device. The body is preferably made of flexible polyvinyl chloride (PVC) tubing or, alternatively, silicone rubber with a shrink wrapping of polytetrafluoroethylene (TEFLON.RTM.). The body is formed to contain the power supply, preferably a plurality of batteries, and a spool of communication wire that connects to a data processing computer external to the piping system.

Zollingger, W. Thor (Martinez, GA); Appel, D. Keith (Aiken, SC); Park, Larry R. (Raleigh, NC)

1995-01-01

313

Apparatus for inspecting piping  

DOEpatents

An inspection rabbit is described for inspecting piping systems having severe bends therein. The rabbit consists of a flexible, modular body containing a miniaturized eddy current inspection probe, a self-contained power supply for proper operation of the rabbit, an outer surface that allows ease of movement through piping systems and means for transmitting data generated by the inspection device. The body is preferably made of flexible polyvinyl chloride (PVC) tubing or, alternatively, silicone rubber with a shrink wrapping of polytetrafluoroethylene (TEFLON{trademark}). The body is formed to contain the power supply, preferably a plurality of batteries, and a spool of communication wire that connects to a data processing computer external to the piping system. 6 figures.

Zollingger, W.T.; Appel, D.K.; Park, L.R.

1995-03-21

314

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

315

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Delivery of benchmark and benchmark-equivalent coverage through managed care entities...ASSISTANCE PROGRAMS SERVICES: GENERAL PROVISIONS Benchmark Benefit and Benchmark-Equivalent Coverage §...

2013-10-01

316

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

317

Excitation and Scattering of Guided Waves-Relationships Between Solutions for Plates and Pipes  

NASA Astrophysics Data System (ADS)

In many important industrial applications the diameter of a pipe is much larger than wall thickness. In this case the approximate theory is applicable, when a pipe is considered as an unwrapped isotropic plate. In this paper, a technique for obtaining pipe mode amplitudes in terms of the solution to the forced 3D problem on a plate is presented. The same principle can be extended to relate guided wave scattering from defects in plates to scattered circumferential modal amplitudes from defects in pipe. Results are shown that illustrate the application of the method to reflection from through thickness circumferential cracks in pipes.

Velichko, A.; Wilcox, P. D.

2008-02-01

318

Heat pipes and use of heat pipes in furnace exhaust  

DOEpatents

An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

Polcyn, Adam D. (Pittsburgh, PA) [Pittsburgh, PA

2010-12-28

319

NRC-BNL BENCHMARK PROGRAM ON EVALUATION OF METHODS FOR SEISMIC ANALYSIS OF COUPLED SYSTEMS.  

SciTech Connect

A NRC-BNL benchmark program for evaluation of state-of-the-art analysis methods and computer programs for seismic analysis of coupled structures with non-classical damping is described. The program includes a series of benchmarking problems designed to investigate various aspects of complexities, applications and limitations associated with methods for analysis of non-classically damped structures. Discussions are provided on the benchmarking process, benchmark structural models, and the evaluation approach, as well as benchmarking ground rules. It is expected that the findings and insights, as well as recommendations from this program will be useful in developing new acceptance criteria and providing guidance for future regulatory activities involving licensing applications of these alternate methods to coupled systems.

XU,J.

1999-08-15

320

Scattering of guided waves by circumferential cracks in steel pipes  

NASA Astrophysics Data System (ADS)

A novel numerical procedure is presented in this paper to study wave scattering by circumferential cracks in steel pipes. The study is motivated by the need to develop a quantitative ultrasonic technique to characterize properties of cracks in pipes. By employing wave function expansion in axial direction and decomposing the problem into a symmetry problem and an anti-symmetry problem, a three-dimensional wave scattering problem is then reduced to two quasi-one-dimensional problems. This simplification greatly reduces the computational time. Numerical results for reflection and transmission coefficients of different incident wave modes are presented here for a steel pipe with cracks of arbitrary circumferential lengths and radial depths. They are shown to agree quite well with available experimental data. .

Bai, H.; Shah, A. H.; Popplewell, N.; Datta, S. K.

2001-04-01

321

Insituform Pipe Rehabilation, Construction Report.  

National Technical Information Service (NTIS)

The report covers the construction evaluation of a pipe rehabilitation project where INSITUFORM was used. INSITUFORM is a manufacturer's name for a pipe relining process which uses cold water inversion to propel a thermo-setting resin coated polyester fib...

B. Yedinak K. Highlands

1986-01-01

322

HS06 Benchmark for an ARM Server  

NASA Astrophysics Data System (ADS)

We benchmarked an ARM cortex-A9 based server system with a four-core CPU running at 1.1 GHz. The system used Ubuntu 12.04 as operating system and the HEPSPEC 2006 (HS06) benchmarking suite was compiled natively with gcc-4.4 on the system. The benchmark was run for various settings of the relevant gcc compiler options. We did not find significant influence from the compiler options on the benchmark result. The final HS06 benchmark result is 10.4.

Kluth, Stefan

2014-06-01

323

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,

324

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

325

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

326

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

327

Beneficial impact of coatings on biological generation of sulfide in concrete sewer pipes  

Microsoft Academic Search

Hydrogen sulfide is a serious problem for many municipalities across North America and worldwide. Odor, safety, and corrosion are the major problems associated with the presence of hydrogen sulfide in sewerage systems. This paper investigates the effect on sulfide generation of using innovative coatings in concrete sewer pipes. A pilot-scale model, consisting of three concrete pipes (each 75 cm in length

Esam H. Hewayde; George F. Nakhla; Erez N. Allouche; Prasanna K. Mohan

2007-01-01

328

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

329

Failure Limiting Pipe Expansion Joint.  

National Technical Information Service (NTIS)

The patent application describes a failure limiting pipe expansion joint for fluid conduits. It comprises a bellows, single or multi-ply, welded into each pipe section, a ribbed inner sleeve welded to the pipe at one end of the expansion joint; an outer s...

F. A. Flint

1974-01-01

330

Transient flow in pipe networks  

Microsoft Academic Search

In order to apply the fixed-grid method of characteristics to transient flow in multi-pipe systems, some pipe reaches may not satisfy the Courant condition. Various numerical techniques can be applied for these reaches. In the present study, the finite difference or interpolation techniques are coupled with the method of characteristics. The location of the disproportionate pipe, which does not satisfy

Hossein M. V. Sam Ani; Alireza Khayatzadeh

2002-01-01

331

Pump assisted heat pipe system  

Microsoft Academic Search

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,

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

1988-01-01

332

Optimal disturbances in pipe flows  

Microsoft Academic Search

The growth of optimal disturbances in pipe Poiseuille flow and in a rotating pipe is investigated. In pipe Poiseuille flow the role of a pair of nearly parallel least stable modes, as a key element of the transient growth mechanism, is explored. Temporal and spatial disturbances are analyzed. The time and distance, at which the maximum energy amplification of an

Guy Ben-Dov; Jacob Cohen

2004-01-01

333

Deployable heat-pipe radiator  

NASA Technical Reports Server (NTRS)

Loop temperatures are controlled effectively under varying load conditions. Radiator has four separate pieces of hardware: heat-pipe panel, flexible heat-pipe leader, heat exchanger, fluid header. Single-fluid transport capacities of about 850 watts, corresponding to 51,000 watt-inches, have been achieved in 90 degree bend orientation of heat-pipe header.

Edelstein, F.

1978-01-01

334

Electrohydrodynamically augmented micro heat pipes  

Microsoft Academic Search

For high power density dissipation, micro heat pipes and micro grooves have demonstrated much promise. Several experimental investigations were conducted to evaluate the potential benefits of electrohydrodynamic (EHD) forces on the operation of micro heat pipes. In these experiments, electric fields were used to orient and guide the flow of the dielectric liquid within the micro heat pipes from the

Zhiquan Yu

2001-01-01

335

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

336

No free lunch and benchmarks.  

PubMed

We extend previous results concerning black box search algorithms, presenting new theoretical tools related to no free lunch (NFL) where functions are restricted to some benchmark (that need not be permutation closed), algorithms are restricted to some collection (that need not be permutation closed) or limited to some number of steps, or the performance measure is given. Minimax distinctions are considered from a geometric perspective, and basic results on performance matching are also presented. PMID:22452316

Duéñez-Guzmán, Edgar A; Vose, Michael D

2013-01-01

337

Description of the Steelquake Benchmark  

NASA Astrophysics Data System (ADS)

A large-size two-storey steel structure with reinforced-concrete slabs was used for a damage detection benchmark. The modal tests at the original and damaged states were performed by impact-hammer excitation. The damage consisted of major cracks at some of the beam-to-column joints and was introduced by seismic testing up to large deformations by means of hydraulic jacks.

Molina, F. J.; Pascual, R.; Golinval, J.-C.

2003-01-01

338

Restaurant Energy Use Benchmarking Guideline  

SciTech Connect

A significant operational challenge for food service operators is defining energy use benchmark metrics to compare against the performance of individual stores. Without metrics, multiunit operators and managers have difficulty identifying which stores in their portfolios require extra attention to bring their energy performance in line with expectations. This report presents a method whereby multiunit operators may use their own utility data to create suitable metrics for evaluating their operations.

Hedrick, R.; Smith, V.; Field, K.

2011-07-01

339

RISKIND verification and benchmark comparisons  

SciTech Connect

This report presents verification calculations and benchmark comparisons for RISKIND, a computer code designed to estimate potential radiological consequences and health risks to individuals and the population from exposures associated with the transportation of spent nuclear fuel and other radioactive materials. Spreadsheet calculations were performed to verify the proper operation of the major options and calculational steps in RISKIND. The program is unique in that it combines a variety of well-established models into a comprehensive treatment for assessing risks from the transportation of radioactive materials. Benchmark comparisons with other validated codes that incorporate similar models were also performed. For instance, the external gamma and neutron dose rate curves for a shipping package estimated by RISKIND were compared with those estimated by using the RADTRAN 4 code and NUREG-0170 methodology. Atmospheric dispersion of released material and dose estimates from the GENII and CAP88-PC codes. Verification results have shown the program to be performing its intended function correctly. The benchmark results indicate that the predictions made by RISKIND are within acceptable limits when compared with predictions from similar existing models.

Biwer, B.M.; Arnish, J.J.; Chen, S.Y.; Kamboj, S.

1997-08-01

340

Defect characterization in pipe-to-pipe welds in large diameter stainless steel piping  

SciTech Connect

Metallurgical evaluation of pipe-to-pipe welds in large-diameter, Type 304 stainless steel piping used to construct the moderator/coolant water systems for Savannah River Site reactors has demonstrated that small weld defects found in this 1950-vintage system do not compromise the integrity of the system. The weld defects were too small for detection by the pre-service standard radiographic inspection, but were found through systematic ultrasonic testing (UT) and penetrant testing (PT) evaluations of piping that had been removed during upgrades to the piping system. The defects include lack of weld penetration, slag inclusions, and other weld metal discontinuities. These discontinuities typically did not propagate during more than 35 years of service. The defects examined were too small and isolated to degrade the mechanical properties of the pipe-to-pipe weldments and therefore did not compromise the integrity of the piping system. 14 refs., 7 figs.

Rawl, D.E. Jr.; West, S.L.; Wheeler, D.A.; Louthan, M.R. Jr.

1990-01-01

341

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

342

Ceramic Heat Pipe Wick.  

National Technical Information Service (NTIS)

A wick for use in a capillary loop pump heat pipe is disclosed. The wick material is an essentially uniformly porous, permeable, open-cell, silicon dioxide/aluminum oxide inorganic ceramic foam having a silica fiber ratio, by weight, of about 78 to 22, re...

B. Seidenberg T. Swanson

1989-01-01

343

Flexible pipe crawling device.  

National Technical Information Service (NTIS)

This invention is comprised of an apparatus for moving through the linear and non-linear segments of piping systems. The apparatus comprises a front leg assembly, a rear leg assembly, means for extension and retraction of said front and rear leg assembles...

W. T. Zollinger

1993-01-01

344

Flexible Heat Pipe  

NASA Technical Reports Server (NTRS)

Narrow Tube carries 10 watts or more to moving parts. Heat pipe 12 inches long and diameter of 0.312 inch (7.92mm). Bent to minimum radius of 2.5 blocks. Flexible section made of 321 stainless steel tubing (Cajon Flexible Tubing or equivalent). Evaporator and condenser made of oxygen free copper. Working fluid methanol.

Bienert, W. B.; Wolf, D. A.

1985-01-01

345

Piping network model program for small computers  

SciTech Connect

A model of fluid piping networks was developed to aid in solving problems in the recirculating water coolant system at the Portsmouth Gaseous Diffusion Plant. The piping network model can be used to solve steady state problems in which water flow rates and temperatures are to be determined, or in which temperature is an important factor in determining pressure losses. The model can be implemented on desktop computers to perform these calculations as needed to track changing process conditions. The report includes a description of the coolant system, the mathematical development f the computer model, a case study utilizing the model and a listing and sample run of the computer codes. 2 figs., 1 tab.

Kruckenberg, N.E.

1986-07-01

346

Phenomenological model for dispersed bubbly flow in pipes  

Microsoft Academic Search

The ability to predict pressure drop as a function of flow parameters for gas-liquid pipe flows in general and dispersed, bubbly, pipe flows in particular is of considerable importance to a number of industries that utilize two-phase flow systems and processes (for instance, petroleum, chemical, nuclear, and geothermal). An analytical approach to the problem of steady-state, axisymmetrically dispersed, bubbly flow

D. E. Nikitopoulos; Efstathios E. Michaelides

1995-01-01

347

Performance characteristics of gravity-assisted, potassium heat pipes  

SciTech Connect

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 smooth-walled and textured-walled heat pipes was made and a minimum internal surface texturing depth is suggested.

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

1985-01-01

348

A Complete Piping Analysis With Thermal Stratification Loads  

Microsoft Academic Search

The U. S. Nuclear Regulatory Commission (USNRC) had issued Bulletins 88-08, 88-11, 89-90, and 93-38 to address the concerns and problems due to thermal stratification loading during the life span of normal plant operation. The thermal stratification condition typically will cause pipe to bow in on a long horizontal segment. These conditions have not been commonly considered in piping design.

Milton Dong; Hong Ming Lee; Chii Chern

2002-01-01

349

Gas-cooled fast breeder reactor shielding benchmark calculation  

Microsoft Academic Search

This report summarizes the results of a shielding benchmark calculation performed by General Atomic (GA) and Oak Ridge National Laboratory (ORNL). The problem analyzed was a neutron-coupled gamma ray transport calculation of the core blanket shield of the 300-MW(e) gas-cooled fast breeder reactor (GCFR). Comparison of the initial GA and ORNL results indicated good agreement for fast fluxes (E greater

C. A. Rouse; D. R. Mathews; P. K. Koch

1977-01-01

350

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

351

Extension of pipe failure models to consider the absence of data from replaced pipes.  

PubMed

Predictions of the expected number of failures of water distribution network pipes are important to develop an optimal management strategy. A number of probabilistic pipe failure models have been proposed in the literature for this purpose. They have to be calibrated on failure records. However, common data management practices mean that replaced pipes are often absent from available data sets. This leads to a 'survival selection bias', as pipes with frequent failures are more likely to be absent from the data. To address this problem, we propose a formal statistical approach to extend the likelihood function of a pipe failure model by a replacement model. Frequentist maximum likelihood estimation or Bayesian inference can then be applied for parameter estimation. This approach is general and is not limited to a particular failure or replacement model. We implemented this approach with a Weibull-exponential failure model and a simple constant probability replacement model. Based on this distribution assumptions, we illustrated our concept with two examples. First, we used simulated data to show how replacement causes a 'survival selection bias' and how to successfully correct for it. A second example with real data illustrates how a model can be extended to consider covariables. PMID:23726706

Scheidegger, Andreas; Scholten, Lisa; Maurer, Max; Reichert, Peter

2013-07-01

352

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

353

Pipe handling apparatus for reel pipe laying system  

SciTech Connect

An offshore system for laying a continuous length of pipe on the sea bottom from a pipe-carrying reel adapted to be mounted on a carrier vessel having an improved pipe handling and conditioning apparatus for working on the unspooled pipe. The improved apparatus includes a pipe straightener for imparting a reverse plastic bending moment to the unspooled pipe passing therethrough , and which comprises at least two pairs of pipe support rollers, each pair being aligned along the pipe path and mounted for rotational movement about respective rotational axes normal to the pipe path and parallel to the plane of the deck of the carrier vessel, and for pivoting movement about a pivot axis located between and substantially parallel to the respective rotational axes. A straightener carriage mounts the pipe straightening means for movement (1) about a pivot axis substantially parallel to the rotational axis of the reel, (2) in a substantially vertical direction relative to the deck of the carrier vessel, and (3) in a direction substantially parallel to the rotational axis of the reel.

Brown, W.A.; Cha, J.H.; Weldon, H.P.; Whyte, D.G.

1981-01-06

354

Comparative Performance of Isolation Systems for Benchmark Cable-stayed Bridge  

Microsoft Academic Search

Earthquake response of benchmark cable-stayed bridge with different isolation sys- tems is investigated. The selected isolation system consists of high damping rubber bearing (HDRB), lead-rubber bearing (LRB), friction pendulum system (FPS) and resilient-friction base isolator (R-FBI). Considering the phase-I benchmark problem, the ground acceleration is only applied in the longitudinal direction acting simultaneously at all supports. The seismic response of

Purnachandra Saha; R. S. Jangid

2008-01-01

355

Seismic control of benchmark cable-stayed bridge using passive hybrid systems  

Microsoft Academic Search

Earthquake response of benchmark cable-stayed bridge with passive hybrid control systems is investigated. The passive hybrid system consists of high damping rubber bearing, lead-rubber bearing, friction pendulum system and resilient-friction base isolator (R-FBI) supplemented with the linear and non-linear viscous fluid damper (VFD). Considering the phase-I benchmark problem, the ground acceleration is only applied in the longitudinal direction acting simultaneously

Purnachandra Saha; R. S. Jangid

2009-01-01

356

Adapting the SPEC 2000 Benchmark Suite for Simulation-Based Computer Architecture Research  

Microsoft Academic Search

\\u000a The large input datasets in the SPEC 2000 benchmark suite result in unreasonably long simulation times when using detailed\\u000a execution-driven simulators for evaluating future computer architecture ideas. To address this problem, we have an ongoing\\u000a project to reduce the execution times of the SPEC 2000 benchmarks in a quantitatively defensible way. Upon completion of this\\u000a work1, we will have smaller

AJ KleinOsowski; John Flynn; Nancy Meares; David J. Lilja

357

The effect of applying a pipe-joint lubricant to connect ductile iron pipe on off-flavors in drinking water distribution systems  

Microsoft Academic Search

This study was used to help define the contribution to taste and odor problems caused by the application of a pipe-joint lubricant to connect ductile iron pipe in drinking water distribution systems. Tyton Joint Lubricant (TJL) was studied. The lubricant produced odors that are continually oxidized by chlorine or oxygen. The mechanism of oxidative rancidity, one of the major causes

K. E. Wiesenthal; G. Amah; T. Lam; I. H. Suffet

358

Network condition simulator for benchmarking sewer deterioration models.  

PubMed

An accurate description of aging and deterioration of urban drainage systems is necessary for optimal investment and rehabilitation planning. Due to a general lack of suitable datasets, network condition models are rarely validated, and if so with varying levels of success. We therefore propose a novel network condition simulator (NetCoS) that produces a synthetic population of sewer sections with a given condition-class distribution. NetCoS can be used to benchmark deterioration models and guide utilities in the selection of appropriate models and data management strategies. The underlying probabilistic model considers three main processes: a) deterioration, b) replacement policy, and c) expansions of the sewer network. The deterioration model features a semi-Markov chain that uses transition probabilities based on user-defined survival functions. The replacement policy is approximated with a condition-class dependent probability of replacing a sewer pipe. The model then simulates the course of the sewer sections from the installation of the first line to the present, adding new pipes based on the defined replacement and expansion program. We demonstrate the usefulness of NetCoS in two examples where we quantify the influence of incomplete data and inspection frequency on the parameter estimation of a cohort survival model and a Markov deterioration model. Our results show that typical available sewer inventory data with discarded historical data overestimate the average life expectancy by up to 200 years. Although NetCoS cannot prove the validity of a particular deterioration model, it is useful to reveal its possible limitations and shortcomings and quantifies the effects of missing or uncertain data. Future developments should include additional processes, for example to investigate the long-term effect of pipe rehabilitation measures, such as inliners. PMID:21803394

Scheidegger, A; Hug, T; Rieckermann, J; Maurer, M

2011-10-15

359

Spent Fuel Criticality Benchmark Experiments  

SciTech Connect

Characteristics between commercial spent fuel waste packages (WP), Laboratory Critical Experiments (LCEs), and commercial reactor critical (CRC) evaluations are compared in this work. Emphasis is placed upon comparisons of CRC benchmark results and the relative neutron flux spectra in each system. Benchmark evaluations were performed for four different pressurized water reactors using four different sets of isotopes. As expected, as the number of fission products used to represent the burned fuel inventory approached reality, the closer to unity k{sub eff} became. Examination of material and geometry characteristics indicate several fundamental similarities between the WP and CRC systems. In addition, spectral evaluations were performed on a representative pressurized water reactor CRC, a 21-assembly area of the core modeled in a potential WP configuration, and three LCEs considered applicable benchmarks for storage packages. Fission and absorption reaction spectra as well as relative neutron flux spectra are generated and compared for each system. The energy dependent reaction rates are the product of the neutron flux spectrum and the energy dependent total macroscopic cross section. With constant source distribution functions, and the total macroscopic cross sections for the fuel region in the CRCs and WP being composed of nearly the same isotopics, the resulting relative flux spectra in the CRCs and WP are very nearly the same. Differences in the relative neutron flux spectra between WPs and CRCs are evident in the thermal energy range as expected. However, the relative energy distribution of the absorption, fission, and scattering reaction rates in both the CRCs and the WP are essentially the same.

J.M. Scaglione

2001-07-23

360

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

361

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

362

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

363

Benchmarking for the competitive marketplace.  

PubMed

One would get little argument these days regarding the importance of performance measurement in the health care industry. The traditional approach has been the straightforward use of measurable units such as financial comparisons and clinical indicators (e.g., length of stay). Also we in the health care industry have traditionally benchmarked our performance and strategies against those most like ourselves. Today's competitive market demands a more customer-focused set of performance measures that go beyond traditional approaches such as customer service. The most important task in today's environment is to study the customers' emerging priorities and adjust our business to meet those priorities. PMID:11184882

Clarke, R W; Sucher, T O

1999-07-01

364

Explosive welding of pipes  

NASA Astrophysics Data System (ADS)

For connection by welding it is suggested to use the explosive welding method. This method is rather new. Nevertheless, it has become commonly used among the technological developments. This method can be advantageous (saving material and physical resources) comparing to its statical analogs (electron-beam welding, argon-arc welding, plasma welding, gas welding, etc.), in particular, in hard-to-reach areas due to their geographic and climatic conditions. The suggestion is to use water as filler. The principle of non-compressibility of liquid under quasi-dynamic loading is used. In one-dimensional gasdynamic and elastic-plastic calculations we determined non-deformed mass of water. Model experiments with pipes having radii R = 57 mm confirmed results of the calculations and the possibility in principle to weld pipes by explosion with use of water as filler.

Drennov, O.; Burtseva, O.; Kitin, A.

2006-08-01

365

Drill pipe protector development  

SciTech Connect

The Geothermal Drilling Organization (GDO), formed in the early 1980s by the geothermal industry and the U.S. Department of Energy (DOE) Geothermal Division, sponsors specific development projects to advance the technologies used in geothermal exploration, drilling, and production phases. Individual GDO member companies can choose to participate in specific projects that are most beneficial to their industry segment. Sandia National Laboratories is the technical interface and contracting office for the DOE in these projects. Typical projects sponsored in the past have included a high temperature borehole televiewer, drill bits, muds/polymers, rotary head seals, and this project for drill pipe protectors. This report documents the development work of Regal International for high temperature geothermal pipe protectors.

Thomerson, C.; Kenne, R. [Regal International Corp., Corsicanna, TX (United States); Wemple, R.P. [Sandia National Lab., Albuquerque, NM (United States)] [ed.] [and others

1996-03-01

366

The Zoo, Benchmarks & You: How To Reach the Oregon State Benchmarks with Zoo Resources.  

ERIC Educational Resources Information Center

This document aligns Oregon state educational benchmarks and standards with Oregon Zoo resources. Benchmark areas examined include English, mathematics, science, social studies, and career and life roles. Brief descriptions of the programs offered by the zoo are presented. (SOE)

2002

367

A protein-DNA docking benchmark  

PubMed Central

We present a protein–DNA docking benchmark containing 47 unbound–unbound test cases of which 13 are classified as easy, 22 as intermediate and 12 as difficult cases. The latter shows considerable structural rearrangement upon complex formation. DNA-specific modifications such as flipped out bases and base modifications are included. The benchmark covers all major groups of DNA-binding proteins according to the classification of Luscombe et al., except for the zipper-type group. The variety in test cases make this non-redundant benchmark a useful tool for comparison and development of protein–DNA docking methods. The benchmark is freely available as download from the internet.

van Dijk, Marc; Bonvin, Alexandre M. J. J.

2008-01-01

368

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

369

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

370

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

371

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

372

Thirty years of fiberglass pipe in oilfield applications: A historical perspective  

SciTech Connect

A 30-year history of the use of fiberglass piping (FRP) systems for oil production piping is presented. Speculation about future uses of FRP in the oilfields is discussed. Problems encountered during the introduction of this type of pipe to the oilfields, and the evolution of early oilfield FRP systems is described. Improvements in FRP during the period of recent oilfield growth are reported. A representative list of significant uses of FRP in oilfield applications today is presented.

Oswald, K.J. [Smith Fiberglass Products Inc., Little Rock, AR (United States)

1996-05-01

373

Piezometric pressure measurements for water flow in a pipe with electrified inner surface  

Microsoft Academic Search

A novel approach to pipe flow improvement is presented on the basis of positive electric voltages applied to the pipe. The\\u000a flow improvement is measured by piezometry. A common problem, connected with all forms of transport of fluids in pipes, is\\u000a loss of pressure due to the friction, i.e. piezometric pressure loss. If the friction depends upon the fluid and

M. Waskaas

2006-01-01

374

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

375

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

376

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

377

Acoustic radiation from a circular pipe with an infinite flange  

NASA Astrophysics Data System (ADS)

The reflection of sound from the end of a flanged pipe is solved in a manner simpler than the procedure of Nomura et al. (1960 Journal of the Physical Society of Japan15, 510-517). Numerical calculations give the low-frequency end correction length as 0·82159… radii, which is very close to Rayleigh's conjectured value of 0·82 radii. The power gain in the transmitted region is illustrated as a function of angle for frequencies below the first cut-off. The related problem of the acoustic response in a flanged pipe when a plane wave is incident upon the pipe in the axial direction is also discussed. Some approximate formulae are presented for the reflection coefficients of flanged and unflanged pipes.

Norris, A. N.; Sheng, I. C.

1989-11-01

378

High Toughness ERW Pipes for Arctic Use.  

National Technical Information Service (NTIS)

Recent progress of ERW pipe manufacturing technology has made it possible for ERW pipes to substitute UOE and stainless pipes in several fields. In order to develop ERW pipe available for line pipe with high toughness at low temperature, the fundamental s...

T. Shimomura T. Takamura S. Ishiro T. Sugayoshi Y. Nagahama

1987-01-01

379

Request for Proposal 77. Horizontal Pipe Racker.  

National Technical Information Service (NTIS)

A pipe handling system will be required on the Mohole drilling platform for storing and handling a maximum quantity of 39,000 feet of drill pipe and 19,000 feet of riser pipe. An automated pipe racking system was required as an integral part of the pipe h...

1965-01-01

380

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.

381

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

382

Tsunami Modeling: Development of Benchmarked Models  

NASA Astrophysics Data System (ADS)

We discuss the progress towards the development of benchmarked models for forecasting tsunami inundation. Tsunami hydrodynamics has progressed slower than research in other natural hazards, because for several decades only the largest tsunamis were being reported. With the exception of the 1960 and 1964 events, there had been only qualitative information on inundation. While the basic equations for analysis have been known for decades, the existing synthesis leading to real time forecasts as currently available had to await the development of sophisticated modeling tools, the large-scale laboratory experiments in the 1980s-1990s and the tsunameter recordings of 2003 and since. The field survey results in the 1990s (Synolakis and Okal, 2005) served as crude proxies to free-field tsunami recordings and allowed for the validation and verification of numerical procedures. State-of-the-art inundation and forecasting codes have evolved through a painstaking process of careful validation and verification which can be traced back to the 1990 NSF Catalina workshop on Long-Wave Runup Models (Liu et al., 1991). Operational tsunami forecasting was only made possible through the availability of deep ocean measurements. We will describe this journey from development of the basic field equations to forecasts, through the scientific milestones that served as benchmarks and reality checks. In summary, as research in live networks -where problems and solution ideas arise spontaneously- tsunami hydrodynamic modeling was driven by milestone scientific meetings, and post tsunami surveys that kept identifying novel problem geometries and previously unrecognized phenomena. We discuss necessary validation and verification steps for numerical codes to be used for inundation mapping, design and operations (Synolakis et al., 2007). Liu, P. L.-F., C. E. Synolakis and H. H. Yeh, 1991. Report on the International Workshop on Long-Wave Run- up. J. Fluid Mech., 229, 675-688. Synolakis, C. E. and E. A. Okal, 2005. 1992-2002: perspective on a decade of post tsunami surveys. Adv. Nat. Technol. Hazards, 23, 1-30. Synolakis, C. E., E. N. Bernard, V. V. Titov, U. Kanoglu and F. Gonzalez, 2007. Standards, criteria, and procedures for NOAA evaluation of tsunami numerical models. NOAA OAR Special Report, Contribution No 3053, NOAA/OAR/PMEL, Seattle, WA, 55 pp.

Kanoglu, U.; Synolakis, C. E.

2008-12-01

383

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

384

Identifying priority issues in facilities management benchmarking  

Microsoft Academic Search

Considers the state of benchmarking in facilities management and finds that most academic and practice literature is mainly concerned with measurement techniques, and a formal approach of reducing performance gaps. Limitations are discussed, and the orientation of facilities management performance priorities is questioned. Argues that benchmarking is limited by the ability to identify the priorities, or performance indicators, that can

Gavin McDougall; John Hinks

2000-01-01

385

Shielding Integral Benchmark Archive and Database (SINBAD)  

Microsoft Academic Search

The Shielding Integral Benchmark Archive and Database (SINBAD) collection of benchmarks was initiated in the early 1990s. SINBAD is an international collaboration between the Organization for Economic Cooperation and Development's Nuclear Energy Agency Data Bank (OECD\\/NEADB) and the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory (ORNL). SINBAD is a major attempt to compile experiments and corresponding

Bernadette Lugue Kirk; Robert E Grove; I. Kodeli; Enrico Sartori; J. Gulliford

2011-01-01

386

Benchmarking, Total Quality Management, and Libraries.  

ERIC Educational Resources Information Center

Discussion of the use of Total Quality Management (TQM) in higher education and academic libraries focuses on the identification, collection, and use of reliable data. Methods for measuring quality, including benchmarking, are described; performance measures are considered; and benchmarking techniques are examined. (11 references) (MES)

Shaughnessy, Thomas W.

1993-01-01

387

VHSIC Hardware Description Language (VHDL) Benchmark Suite.  

National Technical Information Service (NTIS)

This report documents the development of a VHDL Benchmark Suite system. Each benchmark is designed to test one or more of a set of 71 VHDL language features in terms of the limitations of user's of vendor's system architecture, operating system, and VHDL ...

K. Serafino

1989-01-01

388

OCTALIS benchmarking: comparison of four watermarking techniques  

Microsoft Academic Search

In this paper, benchmarking results of watermarking techniques are presented. The benchmark includes evaluation of the watermark robustness and the subjective visual image quality. Four different algorithms are compared, and exhaustively tested. One goal of these tests is to evaluate the feasibility of a Common Functional Model (CFM) developed in the European Project OCTALIS and determine parameters of this model,

Laurent Piron; Michael Arnold; Martin Kutter; Wolfgang Funk; Jean M. Boucqueau; Fiona Craven

1999-01-01

389

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

390

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

391

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

392

Benchmark Dose Modeling - Basic Methodologies Course  

EPA Science Inventory

Benchmark Dose Modeling – Basic Methodologies Course The objective of this full-day course is to provide participants with interactive training on the use of the U.S. Environmental Protection Agency’s (EPA) Benchmark Dose Software (BMDS) and its application to risk as...

393

Benchmarking Learning and Teaching: Developing a Method  

ERIC Educational Resources Information Center

Purpose: To develop a method for benchmarking teaching and learning in response to an institutional need to validate a new program in Dentistry at the University of Sydney, Australia. Design/methodology/approach: After a collaborative partner, University of Adelaide, was identified, the areas of teaching and learning to be benchmarked, PBL…

Henderson-Smart, Cheryl; Winning, Tracey; Gerzina, Tania; King, Shalinie; Hyde, Sarah

2006-01-01

394

29 CFR 1952.213 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Compliance staffing benchmarks. 1952.213 Section 1952.213... § 1952.213 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall compliance staffing levels (benchmarks) necessary for a âfully...

2013-07-01

395

29 CFR 1952.293 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 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 âfully...

2013-07-01

396

29 CFR 1952.203 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 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 âfully...

2013-07-01

397

29 CFR 1952.93 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 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 âfully...

2013-07-01

398

29 CFR 1952.223 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 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 âfully...

2013-07-01

399

42 CFR 440.330 - Benchmark health benefits coverage.  

Code of Federal Regulations, 2010 CFR

... 4 2009-10-01 2009-10-01 false Benchmark health benefits coverage. 440.330 Section...PROGRAMS SERVICES: GENERAL PROVISIONS Subpart C-Benchmark Benefit and Benchmark-Equivalent Coverage § 440.330...

2009-10-01

400

29 CFR 1952.353 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 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 âfully...

2013-07-01

401

42 CFR 425.602 - Establishing the benchmark.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Establishing the benchmark. 425.602 Section 425.602 ...Losses § 425.602 Establishing the benchmark. (a) Computing per capita Medicare Part A and Part B benchmark expenditures. In computing an...

2013-10-01

402

29 CFR 1952.113 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Compliance staffing benchmarks. 1952.113 Section 1952.113... § 1952.113 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall, compliance staffing levels (benchmarks) necessary for a âfully...

2013-07-01

403

29 CFR 1952.233 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 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 âfully...

2013-07-01

404

29 CFR 1952.323 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 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 âfully...

2013-07-01

405

29 CFR 1952.343 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 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 âfully...

2013-07-01

406

42 CFR 440.330 - Benchmark health benefits coverage.  

Code of Federal Regulations, 2010 CFR

... 4 2010-10-01 2010-10-01 false Benchmark health benefits coverage. 440.330 Section...ASSISTANCE PROGRAMS SERVICES: GENERAL PROVISIONS Benchmark Benefit and Benchmark-Equivalent Coverage § 440.330...

2010-10-01

407

42 CFR 457.420 - Benchmark health benefits coverage.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Benchmark health benefits coverage. 457.420 Section...Requirements: Coverage and Benefits § 457.420 Benchmark health benefits coverage. Benchmark coverage is health benefits coverage...

2013-10-01

408

29 CFR 1952.373 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Compliance staffing benchmarks. 1952.373 Section 1952.373... § 1952.373 Compliance staffing benchmarks. Under the terms of the 1978 Court...Marshall compliance staffing levels (benchmarks) necessary for a âfully...

2013-07-01

409

29 CFR 1952.163 - Compliance staffing benchmarks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 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 âfully...

2013-07-01

410

Longitudinal welded pipes with enhanced fatigue strength (Hifa ® pipe)  

Microsoft Academic Search

The transportation and storage of fluids in pipes can lead to cyclic loading due to fluctuating internal pressure which exceeds the normal pipeline operation range. In this special case, the design of the pipe is based on the fatigue strength rather than on the static strength. Normally a welded structure has a reduced fatigue resistance compared to a none- welded

M. Erdelen-Peppler; G. Knauf; Marewski Salzgitter; Mannesmann Forschung; O. Reepmeyer

411

A novel and well-defined benchmarking method for second generation read mapping  

PubMed Central

Background Second generation sequencing technologies yield DNA sequence data at ultra high-throughput. Common to most biological applications is a mapping of the reads to an almost identical or highly similar reference genome. The assessment of the quality of read mapping results is not straightforward and has not been formalized so far. Hence, it has not been easy to compare different read mapping approaches in a unified way and to determine which program is the best for what task. Results We present a new benchmark method, called Rabema (Read Alignment BEnchMArk), for read mappers. It consists of a strict definition of the read mapping problem and of tools to evaluate the result of arbitrary read mappers supporting the SAM output format. Conclusions We show the usefulness of the benchmark program by performing a comparison of popular read mappers. The tools supporting the benchmark are licensed under the GPL and available from http://www.seqan.de/projects/rabema.html.

2011-01-01

412

Modeling coupled blast/structure interaction with Zapotec, benchmark calculations for the Conventional Weapon Effects Backfill (CONWEB) tests.  

SciTech Connect

Modeling the response of buried reinforced concrete structures subjected to close-in detonations of conventional high explosives poses a challenge for a number of reasons. Foremost, there is the potential for coupled interaction between the blast and structure. Coupling enters the problem whenever the structure deformation affects the stress state in the neighboring soil, which in turn, affects the loading on the structure. Additional challenges for numerical modeling include handling disparate degrees of material deformation encountered in the structure and surrounding soil, modeling the structure details (e.g., modeling the concrete with embedded reinforcement, jointed connections, etc.), providing adequate mesh resolution, and characterizing the soil response under blast loading. There are numerous numerical approaches for modeling this class of problem (e.g., coupled finite element/smooth particle hydrodynamics, arbitrary Lagrange-Eulerian methods, etc.). The focus of this work will be the use of a coupled Euler-Lagrange (CEL) solution approach. In particular, the development and application of a CEL capability within the Zapotec code is described. Zapotec links two production codes, CTH and Pronto3D. CTH, an Eulerian shock physics code, performs the Eulerian portion of the calculation, while Pronto3D, an explicit finite element code, performs the Lagrangian portion. The two codes are run concurrently with the appropriate portions of a problem solved on their respective computational domains. Zapotec handles the coupling between the two domains. The application of the CEL methodology within Zapotec for modeling coupled blast/structure interaction will be investigated by a series of benchmark calculations. These benchmarks rely on data from the Conventional Weapons Effects Backfill (CONWEB) test series. In these tests, a 15.4-lb pipe-encased C-4 charge was detonated in soil at a 5-foot standoff from a buried test structure. The test structure was composed of a reinforced concrete slab bolted to a reaction structure. Both the slab thickness and soil media were varied in the test series. The wealth of data obtained from these tests along with the variations in experimental setups provide ample opportunity to assess the robustness of the Zapotec CEL methodology.

Bessette, Gregory Carl

2004-09-01

413

46 CFR 182.455 - Fuel piping.  

Code of Federal Regulations, 2010 CFR

...thickness of 0.9 millimeters (0.035 inch) except that: (i) Diesel fuel piping of other materials, such as seamless steel pipe or tubing, which provide equivalent safety may be used; (ii) Diesel fuel piping of aluminum is...

2010-10-01

414

Cold Drawn ERW Pipes with Superior Formability,  

National Technical Information Service (NTIS)

Cold drawn ERW pipes have been applied in various fields. Cold drawn pipes show recrystallized microstructures when they are annealed for softening. Cold drawn ERW pipes sometimes show a difficulty in formability during cold working of expanding, swaging ...

T. Adaniya T. Takamura T. Meada F. Nishimura M. Morimoto

1988-01-01

415

Benchmarking Sets for Molecular Docking  

PubMed Central

Ligand enrichment among top-ranking hits is a key metric of molecular docking. To avoid bias, decoys should resemble ligands physically, so that enrichment is not simply a separation of gross features, yet be chemically distinct from them, so that they are unlikely to be binders. We have assembled a directory of useful decoys (DUD), with 2950 ligands for 40 different targets. Every ligand has 36 decoy molecules that are physically similar but topologically distinct, leading to a database of 98,266 compounds. For most targets, enrichment was at least half a log better with uncorrected databases such as the MDDR than with DUD, evidence of bias in the former. These calculations also allowed forty-by-forty cross docking, where the enrichments of each ligand set could be compared for all 40 targets, enabling a specificity metric for the docking screens. DUD is freely available online as a benchmarking set for docking at http://blaster.docking.org/dud/.

Huang, Niu; Shoichet, Brian K.; Irwin, John J.

2012-01-01

416

Benchmarking Multipacting Simulations in VORPAL  

SciTech Connect

We will present the results of benchmarking simulations run to test the ability of VORPAL to model multipacting processes in Superconducting Radio Frequency structures. VORPAL is an electromagnetic (FDTD) particle-in-cell simulation code originally developed for applications in plasma and beam physics. The addition of conformal boundaries and algorithms for secondary electron emission allow VORPAL to be applied to multipacting processes. We start with simulations of multipacting between parallel plates where there are well understood theoretical predictions for the frequency bands where multipacting is expected to occur. We reproduce the predicted multipacting bands and demonstrate departures from the theoretical predictions when a more sophisticated model of secondary emission is used. Simulations of existing cavity structures developed at Jefferson National Laboratories will also be presented where we compare results from VORPAL to experimental data.

C. Nieter, C. Roark, P. Stoltz, K. Tian

2009-05-01

417

KRITZ-2 Experimental Benchmark Analysis  

SciTech Connect

The KRITZ-2 experiment has been adopted by the OECD/NEA Task Force on Reactor-Based Plutonium Disposition for use as a benchmark exercise. The KRITZ-2 experiment consists of three different core configurations (one with near-weapons-grade MOX) with critical conditions a 20 C and 245 C. The KRITZ-2 experiment has calculated the MCU-REA code, which is a continuous energy Monte Carlo code system developed at the Russian Research Center--Kurchatov Institute and is used extensively in the Fissile Materials Disposition Program. The calculated results for k{sub eff} and fission rate distributions are compared with the experimental data and results of other codes. The results are in good agreement with the experimental values.

Pavlovichev, A.M.

2001-09-28

418

Neutronics benchmark experiment on tungsten  

NASA Astrophysics Data System (ADS)

In order to validate neutron cross sections for W, a benchmark experiment was carried out at the Frascati Neutron Generator (FNG), that consisted of the irradiation with 14 MeV neutrons of a tungsten block. Neutron flux and gamma heating were measured inside the block. The results were analysed with the Monte Carlo code MCNP-4C using for W, Fe and Ni the cross sections derived from EFF-2.4 and FENDL-2.0. In the neutron flux case, most of the calculations were in agreement with the experimental data within the total uncertainty using EFF-2.4, while they underestimated the fast neutron flux with increasing depth when using FENDL-2 cross sections. A strong discrepancy was found in the photon production data from the EFF-2.4 and FENDL-2 libraries, producing different values for the gamma heating in the two cases. FENDL-2 calculations showed better agreement with the measurements.

Batistoni, P.; Angelone, M.; Petrizzi, L.; Pillon, M.

2004-08-01

419

Ceramic heat pipe wick  

NASA Technical Reports Server (NTRS)

A wick for use in a capillary loop pump heat pipe is disclosed. The wick material is an essentially uniformly porous, permeable, open-cell, silicon dioxide/aluminum oxide inorganic ceramic foam having a silica fiber ratio, by weight, of about 78 to 22, respectively, a density of 6 lbs/cu ft, and an average pore size of less than 5 microns. A representative material having these characteristics is Lockheed Missile and Space Company, Inc.'s HTP 6-22. This material is fully compatible with the freons and anhydrous ammonia and allows for the use of these very efficient working fluids, and others, in capillary loops.

Seidenberg, Benjamin (inventor); Swanson, Theodore (inventor)

1989-01-01

420

Polymeric heat pipe wick  

NASA Astrophysics Data System (ADS)

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

1988-08-01

421

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...

422

Development of pipe deterioration models for water distribution systems using EPR  

Microsoft Academic Search

The economic and social costs of pipe failures in water and wastewater systems are increasing, putting pressure on utility managers to develop annual replacement plans for critical pipes that balance investment with expected benefits in a risk-based management context. In addition to the need for a strategy for solving such a multi-objective problem, analysts and water system managers need reliable

L. Berardi; O. Giustolisi; D. A. Savic

2008-01-01

423

Optimum material distributions for prescribed apparent fracture toughness in thick-walled FGM circular pipes  

Microsoft Academic Search

This study treats the inverse problem of evaluating optimum material distributions intending to realize prescribed apparent fracture toughness in thick-walled functionally graded material (FGM) circular pipes. The incompatible eigenstrain induced in the pipes after cooling from the sintering temperature due to the nonhomogeneous coefficient of thermal expansion is taken into consideration. An approximation method of finding stress intensity factors for

A. M. Afsar; H. Sekine

2001-01-01

424

Studies on cycle characteristics and application of split heat pipe adsorption ice maker  

Microsoft Academic Search

A split heat pipe adsorption ice maker, which uses a solidified compound adsorbent (calcium chloride and activated carbon)-ammonia as working pair, is studied. The application of split heat pipe technology in this system (ice maker for fishing boat powered by waste heat of exhaust gases from diesel engine) solves the corrosion problem caused by using seawater to cool the adsorber

C. J. Chen; R. Z. Wang; L. W. Wang; Z. S. Lu

2007-01-01

425

Application of ground-penetrating radar to the identification of subsurface piping in blanket peat  

Microsoft Academic Search

Natural soil pipes are common and significant in upland blanket peat catchments yet there are major problems in finding and defining the subsurface pipe networks. This is particularly important because pipeflow can contribute a large proportion of runoff to the river systems in these upland environments and may significantly influence catchment sediment and solute yields. Traditional methods such as digging

J. Holden; T. P. Burt; M. Vilas

2002-01-01

426

Plane flow model of non-Newtonian turbulent stratified flow in wells and pipes  

Microsoft Academic Search

Economical and efficient long-distance oil and natural gas pipe transportation technologies are greatly demanded. Nowadays, oil and gas mixed transportation is gradually put into practice and researchers pay much attention on the theories of two-phase flow in pipe. Methods that can efficiently solve problems of this field are being put forward including hydraulic approach. A new approach, the Rotatable Coordinate

Li Hong-bo; Wu Chao; Zheng Yong-gang

2004-01-01

427

Fusion-bonded epoxy coating defects on weld center line of submerged-arc welded pipe  

Microsoft Academic Search

The problem of weld center line coating defects in fusion-bonded epoxy coatings has occurred on pipe produced in Europe, North America, and Asia. At various times, the defects have been attributed to coating application practices, powder manufacturing, pipe manufacturing, welding methods, and overly critical inspectors. This article details plant experience and experimental trails that led to the identification of the

D. R. Sokol; C. M. Herndon

1990-01-01

428

Benchmarking a Visual-Basic based multi-component one-dimensional reactive transport modeling tool  

NASA Astrophysics Data System (ADS)

We present the details of a comprehensive numerical modeling tool, RT1D, which can be used for simulating biochemical and geochemical reactive transport problems. The code can be run within the standard Microsoft EXCEL Visual Basic platform, and it does not require any additional software tools. The code can be easily adapted by others for simulating different types of laboratory-scale reactive transport experiments. We illustrate the capabilities of the tool by solving five benchmark problems with varying levels of reaction complexity. These literature-derived benchmarks are used to highlight the versatility of the code for solving a variety of practical reactive transport problems. The benchmarks are described in detail to provide a comprehensive database, which can be used by model developers to test other numerical codes. The VBA code presented in the study is a practical tool that can be used by laboratory researchers for analyzing both batch and column datasets within an EXCEL platform.

Torlapati, Jagadish; Prabhakar Clement, T.

2013-01-01

429

Application of neural network method to process planning in ship pipe machining  

NASA Astrophysics Data System (ADS)

Based on artificial neural network for process planning decision in ship pipe manufacturing, a novel method is established by analyzing process characteristics of the ship pipe machining. The process knowledge of pipe machining is shifted from the expression of the external rules to the description of the internal net weight value in order for the net inferring engine to decide the process route of pipe machining rapidly and rightly. Simulation shows that the method can resolve problems of process decision, and overcome the drawbacks of “matching difficulty” and “combination explosion” in traditional intelligent CAPP based on symbol reasoning.

Zhong, Yu-Guang; Qiu, Chang-Hua; Shi, Dong-Yan

2004-12-01

430

Fracture mechanics models developed for piping reliability assessment in light water reactors: piping reliability project  

SciTech Connect

The efforts concentrated on modifications of the stratified Monte Carlo code called PRAISE (Piping Reliability Analysis Including Seismic Events) to make it more widely applicable to probabilistic fracture mechanics analysis of nuclear reactor piping. Pipe failures are considered to occur as the result of crack-like defects introduced during fabrication, that escape detection during inspections. The code modifications allow the following factors in addition to those considered in earlier work to be treated: other materials, failure criteria and subcritical crack growth characteristic; welding residual and vibratory stresses; and longitudinal welds (the original version considered only circumferential welds). The fracture mechanics background for the code modifications is included, and details of the modifications themselves provided. Additionally, an updated version of the PRAISE user's manual is included. The revised code, known as PRAISE-B was then applied to a variety of piping problems, including various size lines subject to stress corrosion cracking and vibratory stresses. Analyses including residual stresses and longitudinal welds were also performed.

Harris, D.O.; Lim, E.Y.; Dedhia, D.D.; Woo, H.H.; Chou, C.K.

1982-06-01

431

Demonstrating Sound Impulses in Pipes.  

ERIC Educational Resources Information Center

Describes a simple, direct method to demonstrate the effects of the boundary conditions on sound impulse reflections in pipes. A graphical display of the results can be made using a pipe, cork, small hammer, microphone, and fast recording electronics. Explains the principles involved. (LZ)

Raymer, M. G.; Micklavzina, Stan

1995-01-01

432

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

433

SRP reactor moderator piping inspections  

SciTech Connect

A program has been planned and initiated to provide inspection of SRP reactor moderator piping for intergranular stress corrosion cracking. Inspections will be accomplished by SRP personnel and subcontractors, using state of the art inspection techniques and equipment. Computerized ultransonic inspection systems are being evaluated on R-Area piping. A related program is in progress to determine acceptance criteria for inspection results.

Sprayberry, R.E.

1984-01-01

434

SRP reactor moderator piping inspections  

Microsoft Academic Search

A program has been planned and initiated to provide inspection of SRP reactor moderator piping for intergranular stress corrosion cracking. Inspections will be accomplished by SRP personnel and subcontractors, using state of the art inspection techniques and equipment. Computerized ultransonic inspection systems are being evaluated on R-Area piping. A related program is in progress to determine acceptance criteria for inspection

Sprayberry

1984-01-01

435

Closed loop pulsating heat pipes  

Microsoft Academic Search

Closed loop pulsating heat pipes (CLPHPs) are complex heat transfer devices having a strong thermo-hydrodynamic coupling governing the thermal performance. In this paper, a wide range of pulsating heat pipes is experimentally studied thereby providing vital information on the parameter dependency of their thermal performance. The influence characterization has been done for the variation of internal diameter, number of turns,

Piyanun Charoensawan; Sameer Khandekar; Manfred Groll; Pradit Terdtoon

2003-01-01

436

Physical principles of heat pipes  

Microsoft Academic Search

Heat pipes are used whenever high rates of heat transfer or the control or conversion of heat flows are required. This book covers the physical principles of operation of heat pipes and choice of working fluid related to temperature range. The authors demonstrate how performance is limited by capillary pumping action in the wick together with impedance to liquid and

M. N. Ivanovskii; V. P. Sorokin; I. V. Yagodkin

1982-01-01

437

Heat-Pipe Wick Characterization.  

National Technical Information Service (NTIS)

The development of liquid metal heat-pipes for use in solar powered Stirling engines has led to an in-depth analysis of heat-pipe wick properties. To model the flow of liquid sodium through the wick its two-phase permeability measurement is of interest. T...

J. L. Jones

2000-01-01

438

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

439

Pipe laying apparatus and method  

Microsoft Academic Search

Apparatus and method are described for laying a pipeline on the bottom of an ocean wherein a wheel-like, buoyant body is adapted to carry a single, continuous length of pipe in the form of horizontal convolutions from a first site at which the pipe is wrapped on the body to a second site where the convolutions are moved into vertical

F. S. Ellers; N. R. Wallace

1981-01-01

440

Pipe crawler with stabilizing midsection  

SciTech Connect

This invention is comprised of a pipe crawler having a midsection that provides the stability and flexibility to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in ``inch worm`` fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting.

Zollinger, W.T.; Treanor, R.C.

1993-09-20

441

Alternate high capacity heat pipe  

NASA Astrophysics Data System (ADS)

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.

1986-10-01

442

Pipe crawler with stabilizing midsection  

DOEpatents

A pipe crawler is described having a midsection that provides the stability and flexibility to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in ''inch worm'' fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting. 5 figures.

Zollinger, W.T.; Treanor, R.C.

1994-12-27

443

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

444

An investigation of corrosion in liquid-metal heat pipes  

SciTech Connect

Research is underway to develop a 75-kW heat pipe to transfer solar energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. The high flux levels and high total power level encountered in this application have made it necessary to use a high-performance wick structure with fibers on the order of 4 to 8 microns in diameter. This fine wick structure is highly susceptible to corrosion damage and plugging, as dissolved contaminants plate out on the evaporator surface. Normal operation of the heat pipe also tends to concentrate contaminants in localized areas of the evaporator surface where heat fluxes are the highest. Sandia National Laboratories is conducting a systematic study to identify procedures that reduce corrosion and contamination problems in liquid-metal heat pipes. A series of heat pipes are being tested to explore different options for cleaning heat-pipe systems. Models are being developed to help understand the overall importance of operating parameters on the life of heat-pipe systems. In this paper, the authors present their efforts to reduce corrosion damage.

Adkins, D.R.; Rawlinson, K.S.; Andraka, C.E.; Showalter, S.K.; Moreno, J.B.; Moss, T.A.; Cordiero, P.G.

1998-08-01

445

Finite element analysis of fluid-filled elastic piping systems  

NASA Technical Reports Server (NTRS)

Two finite element procedures are described for predicting the dynamic response of general 3-D fluid-filled elastic piping systems. The first approach, a low frequency procedure, models each straight pipe or elbow as a sequence of beams. The contained fluid is modeled as a separate coincident sequence axial members (rods) which are tied to the pipe in the lateral direction. The model includes the pipe hoop strain correction to the fluid sound speed and the flexibility factor correction to the elbow flexibility. The second modeling approach, an intermediate frequency procedure, follows generally the original Zienkiewicz-Newton scheme for coupled fluid-structure problems except that the velocity potential is used as the fundamental fluid unknown to symmetrize the coefficient matrices. From comparisons of the beam model predictions to both experimental data and the 3-D model, the beam model is validated for frequencies up to about two-thirds of the lowest fluid-filled labor pipe mode. Accurate elbow flexibility factors are seen to be crucial for effective beam modeling of piping systems.

Everstine, G. C.; Marcus, M. S.; Quezon, A. J.

1983-01-01

446

Analytical Benchmark Test Set for Criticality Code Verification  

SciTech Connect

A number of published numerical solutions to analytic eigenvalue (k{sub eff}) and eigenfunction equations are summarized for the purpose of creating a criticality verification benchmark test set. The 75-problem test set allows the user to verify the correctness of a criticality code for infinite medium and simple geometries in one- and two-energy groups, one- and two-media, and both isotropic and linearly anisotropic neutron scattering. A three- and six-energy group infinite medium problem are also included in the test set. The problem specifications will produce both k{sub eff}=1 and the quoted k{sub {infinity}} to at least five decimal places. Additional uses of the test set for code verification are also discussed. Los Alamos report LA-13511 contains the details of all 75 test problems.

Sood, A.; Forster, R.A.; Parson, D.K.

1999-09-20

447

Geothermal district piping - A primer  

SciTech Connect

Transmission and distribution piping constitutes approximately 40 -60% of the capital costs of typical geothermal district heating systems. Selections of economical piping suitable for the fluid chemistry is critical. Presently, most piping (56%) in geothermal systems is of asbestos cement construction. Some fiberglass (19%) and steel (19%) is also in use. Identification of an economical material to replace asbestos cement is important to future project development. By providing information on relative costs, purchase considerations, existing material performance and new products, this report seeks to provide a background of information to the potential pipe purchaser. A brief discussion of the use of uninsulated piping in geothermal district heating systems is also provided. 5 refs., 19 figs., 1 tab.

Rafferty, K.

1989-11-01

448

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

449

Promethus 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.

AM Girbik; PA Dilorenzo

2006-01-24

450

Effective File I/O Bandwidth Benchmark  

SciTech Connect

The effective I/O bandwidth benchmark (b{_}eff{_}io) covers two goals: (1) to achieve a characteristic average number for the I/O bandwidth achievable with parallel MPI-I/O applications, and (2) to get detailed information about several access patterns and buffer lengths. The benchmark examines ''first write'', ''rewrite'' and ''read'' access, strided (individual and shared pointers) and segmented collective patterns on one file per application and non-collective access to one file per process. The number of parallel accessing processes is also varied and well-formed I/O is compared with non-well formed. On systems, meeting the rule that the total memory can be written to disk in 10 minutes, the benchmark should not need more than 15 minutes for a first pass of all patterns. The benchmark is designed analogously to the effective bandwidth benchmark for message passing (b{_}eff) that characterizes the message passing capabilities of a system in a few minutes. First results of the b{_}eff{_}io benchmark are given for IBM SP and Cray T3E systems and compared with existing benchmarks based on parallel Posix-I/O.

Rabenseifner, R.; Koniges, A.E.

2000-02-15

451

ICSBEP Benchmarks For Nuclear Data Applications  

SciTech Connect

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 [Idaho National Engineering and Environmental Laboratory (United States)

2005-05-24

452

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

453

Analytical Radiation Transport Benchmarks for The Next Century  

SciTech Connect

Verification of large-scale computational algorithms used in nuclear engineering and radiological applications is an essential element of reliable code performance. For this reason, the development of a suite of multidimensional semi-analytical benchmarks has been undertaken to provide independent verification of proper operation of codes dealing with the transport of neutral particles. The benchmarks considered cover several one-dimensional, multidimensional, monoenergetic and multigroup, fixed source and critical transport scenarios. The first approach, called the Green's Function. In slab geometry, the Green's function is incorporated into a set of integral equations for the boundary fluxes. Through a numerical Fourier transform inversion and subsequent matrix inversion for the boundary fluxes, a semi-analytical benchmark emerges. Multidimensional solutions in a variety of infinite media are also based on the slab Green's function. In a second approach, a new converged SN method is developed. In this method, the SN solution is ''minded'' to bring out hidden high quality solutions. For this case multigroup fixed source and criticality transport problems are considered. Remarkably accurate solutions can be obtained with this new method called the Multigroup Converged SN (MGCSN) method as will be demonstrated.

B.D. Ganapol

2005-01-19

454

Benchmarking optimization software with COPS.  

SciTech Connect

The COPS test set provides a modest selection of difficult nonlinearly constrained optimization problems from applications in optimal design, fluid dynamics, parameter estimation, and optimal control. In this report we describe version 2.0 of the COPS problems. The formulation and discretization of the original problems have been streamlined and improved. We have also added new problems. The presentation of COPS follows the original report, but the description of the problems has been streamlined. For each problem we discuss the formulation of the problem and the structural data in Table 0.1 on the formulation. The aim of presenting this data is to provide an approximate idea of the size and sparsity of the problem. We also include the results of computational experiments with the LANCELOT, LOQO, MINOS, and SNOPT solvers. These computational experiments differ from the original results in that we have deleted problems that were considered to be too easy. Moreover, in the current version of the computational experiments, each problem is tested with four variations. An important difference between this report and the original report is that the tables that present the computational experiments are generated automatically from the testing script. This is explained in more detail in the report.

Dolan, E.D.; More, J.J.

2001-01-08

455

An enhanced RNA alignment benchmark for sequence alignment programs  

PubMed Central

Background The performance of alignment programs is traditionally tested on sets of protein sequences, of which a reference alignment is known. Conclusions drawn from such protein benchmarks do not necessarily hold for the RNA alignment problem, as was demonstrated in the first RNA alignment benchmark published so far. For example, the twilight zone – the similarity range where alignment quality drops drastically – starts at 60 % for RNAs in comparison to 20 % for proteins. In this study we enhance the previous benchmark. Results The RNA sequence sets in the benchmark database are taken from an increased number of RNA families to avoid unintended impact by using only a few families. The size of sets varies from 2 to 15 sequences to assess the influence of the number of sequences on program performance. Alignment quality is scored by two measures: one takes into account only nucleotide matches, the other measures structural conservation. The performance order of parameters – like nucleotide substitution matrices and gap-costs – as well as of programs is rated by rank tests. Conclusion Most sequence alignment programs perform equally well on RNA sequence sets with high sequence identity, that is with an average pairwise sequence identity (APSI) above 75 %. Parameters for gap-open and gap-extension have a large influence on alignment quality lower than APSI ? 75 %; optimal parameter combinations are shown for several programs. The use of different 4 × 4 substitution matrices improved program performance only in some cases. The performance of iterative programs drastically increases with increasing sequence numbers and/or decreasing sequence identity, which makes them clearly superior to programs using a purely non-iterative, progressive approach. The best sequence alignment programs produce alignments of high quality down to APSI > 55 %; at lower APSI the use of sequence+structure alignment programs is recommended.

Wilm, Andreas; Mainz, Indra; Steger, Gerhard

2006-01-01

456

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

457

ASIS healthcare security benchmarking study.  

PubMed

Effective security has aligned itself into the everyday operations of a healthcare organization. This is evident in every regional market segment, regardless of size, location, and provider clinical expertise or organizational growth. This research addresses key security issues from an acute care provider to freestanding facilities, from rural hospitals and community hospitals to large urban teaching hospitals. Security issues and concerns are identified and addressed daily by senior and middle management. As provider campuses become larger and more diverse, the hospitals surveyed have identified critical changes and improvements that are proposed or pending. Mitigating liabilities and improving patient, visitor, and/or employee safety are consequential to the performance and viability of all healthcare providers. Healthcare organizations have identified the requirement to compete for patient volume and revenue. The facility that can deliver high-quality healthcare in a comfortable, safe, secure, and efficient atmosphere will have a significant competitive advantage over a facility where patient or visitor security and safety is deficient. Continuing changes in healthcare organizations' operating structure and healthcare geographic layout mean changes in leadership and direction. These changes have led to higher levels of corporate responsibility. As a result, each organization participating in this benchmark study has added value and will derive value for the overall benefit of the healthcare providers throughout the nation. This study provides a better understanding of how the fundamental security needs of security in healthcare organizations are being addressed and its solutions identified and implemented. PMID:11602980

2001-01-01

458

Theoretical and Simulated Analysis of Guided Waves Propagating in Fluid-Filled Pipes  

NASA Astrophysics Data System (ADS)

To keep the safety of nuclear power plants, nondestructive evaluation (NDE) of cylindrical pipes, which carry hot water, is an issue of a great interest. Ultrasonic methods using bulk wave are commonly used for NDE of such pipes, however still having problems that the methods consume a long time to inspect large areas. On the other hand, NDE methods using guided wave should overcome this problem because the guided wave has a characteristic of long propagation range. Nevertheless, there have been few investigations to clarify the behavior of the guided wave in the fluid-filled cylindrical pipes. We therefore developed an analytical method to calculate particle displacement, and we compared the dispersion curves, cut-off frequencies, and particle displacements of guided waves propagating in the hollow pipe and the fluid-filled pipe.

Harumichi Sato,; Hisato Ogiso,

2010-07-01

459

Disinfection Profiling and Benchmarking Guidance Manual.  

National Technical Information Service (NTIS)

The objective of this guidance manual is to help Public Water Systems (PWSs) in implementing the practice of disinfection profiling and benchmarking as required under the interim Enhanced Surface Water Treatment Rule (IESWTR) promulgated December 16, 1998...

1999-01-01

460

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

461

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

462

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

463

Benchmark calculations of power distribution within assemblies.  

National Technical Information Service (NTIS)

The main objective of this Benchmark is to compare different techniques for fine flux prediction based upon coarse mesh diffusion or transport calculations. We proposed 5 'core' configurations including different assembly types (17 x 17 pins, 'uranium', '...

C. Cavarec J. F. Perron D. Verwaerde J. P. West

1994-01-01

464

XWeB: The XML Warehouse Benchmark  

NASA Astrophysics Data System (ADS)

With the emergence of XML as a standard for representing business data, new decision support applications are being developed. These XML data warehouses aim at supporting On-Line Analytical Processing (OLAP) operations that manipulate irregular XML data. To ensure feasibility of these new tools, important performance issues must be addressed. Performance is customarily assessed with the help of benchmarks. However, decision support benchmarks do not currently support XML features. In this paper, we introduce the XML Warehouse Benchmark (XWeB), which aims at filling this gap. XWeB derives from the relational decision support benchmark TPC-H. It is mainly composed of a test data warehouse that is based on a unified reference model for XML warehouses and that features XML-specific structures, and its associate XQuery decision support workload. XWeB's usage is illustrated by experiments on several XML database management systems.

Mahboubi, Hadj; Darmont, Jérôme

465

Benchmarking ORTEC Isotopic Measurements and Calculations.  

National Technical Information Service (NTIS)

This report represents a description of compiled benchmark tests conducted to probe and to demonstrate the extensive utility of the Ortec ISOTOPIC (gamma)-ray analysis computer program. The ISOTOPIC program performs analyses of (gamma)-ray spectra applied...

B. N. Nitin C. V. Vito R. Dewberry S. R. Raymond

2008-01-01

466

Public Relations in Accounting: A Benchmark Study.  

ERIC Educational Resources Information Center

Reports on a national study of one segment of the professional services market: the accounting profession. Benchmark data on CPA firms' attitudes toward and uses of public relations are presented and practical and theoretical/research issues are discussed. (JC)

Pincus, J. David; Pincus, Karen V.

1987-01-01

467

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

468

DOE Commercial Building Benchmark Models: Preprint  

SciTech Connect

To provide a consistent baseline of comparison and save time conducting such simulations, the U.S. Department of Energy (DOE) has developed a set of standard benchmark building models. This paper will provide an executive summary overview of these benchmark buildings, and how they can save building analysts valuable time. Fully documented and implemented to use with the EnergyPlus energy simulation program, the benchmark models are publicly available and new versions will be created to maintain compatibility with new releases of EnergyPlus. The benchmark buildings will form the basis for research on specific building technologies, energy code development, appliance standards, and measurement of progress toward DOE energy goals. Having a common starting point allows us to better share and compare research results and move forward to make more energy efficient buildings.

Torcelini, P.; Deru, M.; Griffith, B.; Benne, K.; Halverson, M.; Winiarski, D.; Crawley, D. B.

2008-07-01

469

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

470

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

471

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

472

The NAS Parallel Benchmarks 2.0  

Microsoft Academic Search

We describe a set of implementations of the NAS Parallel Benchmarks based on Fortran 77 and the MPI message passing standard. These implementations,which are intended to be run with little or no tuning, approximate the performance a typical user can expect for a portable parallel program on a distributed memory computer. They complement rather than replace the originalNAS Parallel Benchmarks.We

David Bailey; Tim Harris; William Saphir; Rob Van Der Wijngaart; Alex Woo; Maurice Yarrow

1995-01-01

473

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

474

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 [University of Oklahoma; Randerson, James T. [University of California, Irvine; Hoffman, Forrest [ORNL; Norby, Richard J [ORNL

2012-01-01

475

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

476

Heat exchange pipes for a furnace system  

Microsoft Academic Search

This patent describes improvement in a flue products exhaust and preheated combustion air supply assembly for use in association with a heating furnace wherein an air intake pipe is provided outside of and around an exhaust product pipe and wherein each of the pipes extend horizontally to openings outside of a building. It comprises: an air intake pipe and exhaust

1991-01-01

477

Flexible PMMA pipe for terahertz propagation  

NASA Astrophysics Data System (ADS)

We present an experimental study on a flexible terahertz (THz) pipe PMMA waveguide. The attenuation loss of this pipe at 3.1THz was 9.65dB/m. Further more, bending loss of the pipe waveguides was investigated. The experimental result shows good transmission properties of the pipe.

Liu, Jing; Xiao, Mingfei; Shen, Jingling; Zhang, Wei

2012-12-01

478

Heat pipes for industrial waste heat recovery  

Microsoft Academic Search

Development work on the high temperature ceramic recuperator at Los Alamos National Laboratory is described and involved material investigations, fabrication methods development, compatibility tests, heat pipe operation, and the modeling of application conditions based on current industrial usage. Solid ceramic heat pipes, ceramic coated refractory pipes, and high-temperature oxide protected metallic pipes are investigated. Economic studies of the use of

M. A. Merrigan

1981-01-01

479

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

480

The Sacred Pipe in American Indian Religions.  

ERIC Educational Resources Information Center

A bibliographic essay covers all significant literature on the Sacred Pipe among the North American tribes. Organizes over 130 references dating from 1843 to 1980 under topics such as American Indian attitudes toward the pipe, sacramental and ceremonial uses of the pipe, and the pipe as symbolic man. (JHZ)

Steinmetz, Paul B.

1984-01-01

481

Laboratory Load Tests on Buried Flexible Pipe.  

National Technical Information Service (NTIS)

As part of a study on soil factors affecting the behavior of buried pipe, research is being conducted on the soil-structure interaction of buried flexible pipe; earlier tests dealt with rigid pipe. The main items of investigation on flexible pipe are soil...

A. K. Howard

1968-01-01

482

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

483

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

484

Evolution of Synthetic RTL Benchmark Circuits with Predened  

Microsoft Academic Search

he proposed method a new collection of synthetic benchmark circuits was developed. These benchmark circuits will be useful in a validation process of novel algorithms and tools in the area of digital circuits testing. Evolved benchmark circuits currently represent the most complex benchmark circuits with a known level of testability. Furthermore, these circuits are the largest circuits that have ever

TOMAS PECENKA; LUKAS SEKANINA; ZDENEK KOTASEK

485

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

486

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 characteris