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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. 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

3

Piping systems physical benchmarks  

SciTech Connect

Physical benchmark evaluations are used to assess the accuracy and adequacy of the analysis methods and assumptions used in typical piping qualification evaluations. To date physical benchmark evaluations have been completed for five systems involving both laboratory tested and in situ piping. In each evaluation elastic finite element methods are used to predict the time history response of a system for which physical test results are available. In the analytical simulations the measured support excitations and the measured damping properties are used as input and the acceleration and displacement response of piping interior points are predicted as output. Most evaluations were performed blind in that only the measured inputs are provided at the time of analysis. A summary of the overall results as well as predicted and measured time history traces for selected points are included.

Bezler, P.; Subudhi, M.

1985-01-01

4

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

5

MCNP: Neutron benchmark problems  

SciTech Connect

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

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

1991-11-01

6

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

7

MCNP: Criticality safety benchmark problems  

SciTech Connect

This report investigates the suitability of the general purpose Monte Carlo transport code MCNP for criticality safety calculations. The increased use of radiation transport codes for criticality problems has produced a greater user and institutional demand for assurances that such codes give correct results. Responding to these requirements for code validation, MCNP has been benchmarked against the KENO standard test set. MCNP results are compared to KENO calculations, as well as experimental results, where available. A comparison of MCNP continuous energy and multigroup results indicates that the continuous energy cross sections are more accurate, and MCNP successfully predicts the experimental results, in some cases better than KENO, within the expected data and statistical uncertainties. This benchmark study demonstrates that MCNP can accurately and efficiently model a relatively broad spectrum of criticality problems. 24 figs, 3 tabs.

Mendius, P.W. [ed.; Wagner, J.C.; Sisolak, J.E.; McKinney, G.W.

1992-10-01

8

Benchmark Problems for Repository Siting Models.  

National Technical Information Service (NTIS)

This report describes benchmark problems to test computer codes used in siting nuclear waste repositories. Analytical solutions, field problems and hypothetical problems are included. Problems are included for the following types of codes: ground-water fl...

B. Ross J. W. Mercer S. D. Thomas B. H. Lester

1982-01-01

9

Cemented pipe-in-pipe casing strings solve field problems  

SciTech Connect

A severe problem in old producing wells in high pressure areas is casing collapse. To solve it, tests were run on the feasibility of cementing smaller casing inside the larger, deformed pipe. Results were surprising. The collapse resistance of a pipe-in-pipe combination was at least 15 to 30% greater than API specifications and, even when the outer pipe was deformed, resistance was more than sufficient. 4 refs.

Burkowsky, M.; Ott, H.P.; Schillinger, H.

1981-10-01

10

Benchmark solution for unsteady state CFD problems  

SciTech Connect

Unsteady convective dominated flows are very common in engineering and science. There is a need to develop an accurate numerical scheme to predict unsteady flow and heat transfer to understand the physics of instability and the flow evolution process. No numerical scheme is free from errors. It is essential to reduce the numerical errors to some extent, so that the prediction results are dependable. This article suggests two platform problems to test the accuracy of a time marching numerical scheme. One problem is buoyancy driven flow in a differentially heated cavity. This problem has importance in melting and solidification processes. The other problem is the forced flow in an oscillatory lid driven cavity. These problems are chosen because they have well-defined geometry, boundary, and initial conditions, yet the flow exhibits complexity and skewness with the grid line. High-order schemes are used to generate benchmark solutions for the mentioned problems. It is believed that the predicted results are numerically correct and oscillation of the fluid is due to physics of the flow.

Mohamad, A.A. [Eastern Mediterranean Univ., Mersin (Turkey). Mechanical Engineering Dept.

1998-11-13

11

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

12

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

13

In situ and laboratory benchmarking of computed codes used for dynamic-response predictions of nuclear-reactor piping. [PWR; BWR  

Microsoft Academic Search

The ongoing program to develop analytical piping benchmark solutions for the verification of piping analysis methods has been extended to the consideration and use of physical test results. This report provides a description of the first endeavors in this effort. Specifically the results of benchmark evaluations for a laboratory tested piping system undergoing forced seismic excitation and an in situ

P. Bezler; M. Subudhi; S. Shteyngart

1983-01-01

14

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

15

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

16

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

17

Model Predictions to the 2005 Ultrasonic Benchmark Problems  

NASA Astrophysics Data System (ADS)

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

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

2006-03-01

18

Solving two supervisory control benchmark problems using Supremica  

Microsoft Academic Search

Two supervisory control benchmark problems for WODESpsila08 are solved using the tool Supremica. Supremica is a tool for formal synthesis of discrete-event control functions based on discrete event models of the uncontrolled plant and specifications of the desired closed-loop behavior. By using formal synthesis of control functions the need for formal verification is reduced since the control functions are computed

Sajed Miremadi; Knut Åkesson; Martin Fabian; Arash Vahidi; Bengt Lennartson

2008-01-01

19

Workshops and problems for benchmarking eddy current codes  

SciTech Connect

A series of six workshops was held in 1986 and 1987 to compare eddy current codes, using six benchmark problems. The problems included transient and steady-state ac magnetic fields, close and far boundary conditions, magnetic and non-magnetic materials. All the problems were 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. A second two-year series of TEAM (Testing Electromagnetic Analysis Methods) workshops, using six more problems, is underway. 12 refs., 15 figs., 4 tabs.

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

1988-08-01

20

Benchmarking the benchmarking models  

Microsoft Academic Search

Purpose – A review of benchmarking literature revealed that there are different types of benchmarking and a plethora of benchmarking process models. In some cases, a model has been uniquely developed for performing a particular type of benchmarking. This poses the following problems: it can create confusion among the users as to whether they should use only the unique benchmarking

G. Anand; Rambabu Kodali

2008-01-01

21

Benchmark results for the non-equilibrium Marshak diffusion problem.  

NASA Astrophysics Data System (ADS)

As an extension of previous work in the literature, this paper considers a particular one-dimensional, halfspace, non-equilibrium Marshak wave problem. The radiative transfer model employed is a one-group diffusion approximation with Marshak boundary condition, where the radiation and material fields are out of equilibrium. An analytic solution for the distribution of radiative energy and material temperature as a function of space and time to this problem is given and tables of numerical results are generated. These benchmark results, together with the previously published results, are useful as a reference for validating time-dependent radiation diffusion computer codes. A comparison with a finite difference solution is presented which shows excellent agreement when a fine spatial mesh and small time steps are used.

Su, B.; Olson, G. L.

1996-09-01

22

AFEN method and its solutions of the hexagonal three-dimensional VVER-1000 benchmark problem  

Microsoft Academic Search

The unique features of the analytic function expansion nodal (AFEN) method in hexagonal-z geometry are described. The COREDAX code implementing the AFEN method is verified testing on the VVER-440 benchmark problem and a “simplified” VVER-1000 benchmark problem. The COREDAX code then applied to the original VVER-1000 benchmark problem exercise 2 (HZP case and HP case) provides very good results in comparison

Jaejun Lee; Nam Zin Cho

2006-01-01

23

Neutron transport benchmark problem proposal for fast critical assembly without homogenizations  

Microsoft Academic Search

In the present paper, we propose a neutron transport benchmark problem for fast critical assembly without homogenizations. With this problem, we can validate applicability of neutron transport codes when employed in highly heterogeneous fast critical assembly analyses. In addition, this benchmark problem can be used to validate homogenization procedures for slab lattices.Detailed configurations of the cores and the lattices and

Go Chiba; Kazuyuki Numata

2007-01-01

24

Benchmark Problem Suite for Reactor Physics Study of LWR Next Generation Fuels  

Microsoft Academic Search

This paper proposes a benchmark problem suite for studying the physics of next-generation fuels of light water reactors. The target discharge burnup of the next-generation fuel was set to 70 GWd\\/t considering the increasing trend in discharge burnup of light water reactor fuels. The UO2 and MOX fuels are included in the benchmark specifications. The benchmark problem consists of three

Akio YAMAMOTO; Tadashi IKEHARA; Takuya ITO; Etsuro SAJI

2002-01-01

25

A model-oriented benchmark problem for CO2 storage  

Microsoft Academic Search

Simulation of CO2 storage in geological formations inherently involves decisions concerning relevant physics, upscaling, and numerical modeling. We propose a benchmark study designed to assess the impact of these necessary choices, within the context of storage in a conceptually simple geological formation. The benchmark asks for answers to relevant ques- tions regarding the ultimate fate of the injected CO2 plume.

H. K. Dahle; G. T. Eigestad; J. M. Nordbotten; K. Pruess

26

Error Analysis of Variations on Larsen's Benchmark Problem  

SciTech Connect

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 Larsen's test problem are concerned with the incoming flux boundary conditions: unit incoming flux on the left and bottom edges (Larsen's configuration); unit, incoming flux only on the left edge; unit incoming flux only on the bottom edge. The three methods considered are the Diamond Difference (DD) method, and the constant-approximation versions of the Arbitrarily High Order Transport method of the Nodal type (AHOT-N), and of the Characteristic (AHOT-C) type. The cell-wise error is computed as the difference between the cell-averaged flux computed by each method and the exact value, then the L{sub 1}, L{sub 2}, and L{sub {infinity}} error norms are calculated. The results of this study demonstrate that while integral error norms, i.e. L{sub 1}, L{sub 2}, converge to zero with mesh refinement, the pointwise L{sub {infinity}} norm does not due to solution discontinuity across the singular characteristic. Little difference is observed between the error norm behavior of the three methods considered in spite of the fact that AHOT-C is locally exact, suggesting that numerical diffusion across the singular characteristic as the major source of error on the global scale. However, AHOT-C possesses a given accuracy in a larger fraction of computational cells than DD.

Azmy, YY

2001-06-27

27

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

SciTech Connect

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

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

2012-07-01

28

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

29

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

30

A BENCHMARK PROGRAM FOR EVALUATION OF METHODS FOR COMPUTING SEISMIC RESPONSE OF COUPLED BUILDING-PIPING/EQUIPMENT WITH NON-CLASSICAL DAMPING.  

SciTech Connect

Under the auspices of the US Nuclear Regulatory Commission (NRC), Brookhaven National Laboratory (BNL) developed a comprehensive program to evaluate state-of-the-art methods and computer programs for seismic analysis of typical coupled nuclear power plant (NPP) systems with nonclassical damping. In this program, four benchmark models of coupled building-piping/equipment systems with different damping characteristics were analyzed for a suite of earthquakes by program participants applying their uniquely developed methods and computer programs. This paper presents the results of their analyses, and their comparison to the benchmark solutions generated by BNL using time domain direct integration methods. The participant's analysis results established using complex modal time history methods showed good comparison with the BNL solutions, while the analyses produced with either complex-mode response spectrum methods or classical normal-mode response spectrum method, in general, produced more conservative results, when averaged over a suite of earthquakes. However, when coupling due to damping is significant, complex-mode response spectrum methods performed better than the classical normal-mode response spectrum method. Furthermore, as part of the program objectives, a parametric assessment is also presented in this paper, aimed at evaluation of the applicability of various analysis methods to problems with different dynamic characteristics unique to coupled NPP systems. It is believed that the findings and insights learned 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.; Degrassi, G.; Chokshi, N.

2001-03-22

31

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

32

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

33

Benchmark problems for mixtures of rarefied gases. I. Couette flow  

NASA Astrophysics Data System (ADS)

The planar Couette flow for gaseous mixture He-Ar is calculated by the direct simulation Monte Carlo method based on ab initio potential over the whole range of the gas rarefaction for several values of the mole fraction and for two values of the wall speed. The smaller value of the speed corresponds to the limit when the nonlinear terms are negligible, while the larger value describes a nonlinear flow. The shear stress, velocity gradient, temperature, and mole fraction profiles are presented. The reported results can be used as benchmark data to test model kinetic equations for gaseous mixtures. To study the influence of the intermolecular potential, the same simulations are carried out for the hard sphere molecular model. A relative deviation of the results based on this model from those based on the ab initio potential are analyzed. It is pointed out that the difference between the shear stresses of the two potentials for the linearized solution is within 1%, while it reaches 6% for the nonlinear cases.

Sharipov, Felix; Strapasson, José L.

2013-02-01

34

A Comparative Study of Artificial Bee Colony, Bees Algorithms and Differential Evolution on Numerical Benchmark Problems  

Microsoft Academic Search

\\u000a In this paper, performance of basic Artificial Bee Colony, Bees and Differential evolution algorithms is compared on eight\\u000a well-known benchmark problems. Most of experimental results show that the DE\\/best\\/1\\/exp scheme has the best performance on unimodal problems, Bees algorithm has the second performance except Quadric and Rosenbrock\\u000a functions. On multimodal problems Bees algorithm has the best performance, and Artificial Bee

Huanzhe Li; Kunqi Liu; Xia Li

35

C5 Benchmark Problem with Discrete Ordinate Radiation Transport Code DENOVO  

Microsoft Academic Search

The C5 benchmark problem proposed by the Organisation for Economic Co-operation and Development\\/Nuclear Energy Agency was modeled to examine the capabilities of Denovo, a three-dimensional (3-D) parallel discrete ordinates (S{sub N}) radiation transport code, for problems with no spatial homogenization. Denovo uses state-of-the-art numerical methods to obtain accurate solutions to the Boltzmann transport equation. Problems were run in parallel on

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

2011-01-01

36

Benchmarking of two-phase flow through safety relief valves and pipes  

Microsoft Academic Search

This paper compares calculated results for two-phase flows through safety relief valves and pipes using the TPHEM, CCFLOW and RRERSP computer programs. These studies were conducted to locate errors in the programs as well as to further our understanding of how each program worked. For most low-to-moderate viscosity flow examples, and for the frozen flow examples, the program results agreed

Shawn P. Adair; Harold G. Fisher

1999-01-01

37

Analysis of the NEACRP PWR rod ejection benchmark problems with DIF3D-K.  

National Technical Information Service (NTIS)

Analyses of the NEACRP PWR rod ejection transient benchmark problems with the DIF3D-K nodal kinetics code are presented. The DIF3D-K results are shown to be in generally good agreement with results obtained using other codes, in particular reference resul...

M. H. Kim T. A. Taiwo H. S. Khalil

1994-01-01

38

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

39

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

SciTech Connect

The expected increased demand in fuel for nuclear power plants, combined with the fact that a significant portion of the current supply from the blend down of weapons-source material will soon be coming to an end, has led to the need for new sources of enriched uranium for nuclear fuel. As a result, a number of countries have announced plans, or are currently building, gaseous centrifuge enrichment plants (GCEPs) to supply this material. GCEPs have the potential to produce uranium at enrichments above the level necessary for nuclear fuel purposes-enrichments that make the uranium potentially usable for nuclear weapons. As a result, there is a critical need to monitor these facilities to ensure that nuclear material is not inappropriately enriched or diverted for unintended use. Significant advances have been made in instrument capability since the current International Atomic Energy Agency (IAEA) monitoring methods were developed. In numerous cases, advances have been made in other fields that have the potential, with modest development, to be applied in safeguards applications at enrichment facilities. A particular example of one of these advances is the flow and enrichment monitor (FEMO). (See Gunning, J. E. et al., 'FEMO: A Flow and Enrichment Monitor for Verifying Compliance with International Safeguards Requirements at a Gas Centrifuge Enrichment Facility,' Proceedings of the 8th International Conference on Facility Operations - Safeguards Interface. Portland, Oregon, March 30-April 4th, 2008.) The FEMO is a conceptual instrument capable of continuously measuring, unattended, the enrichment and mass flow of {sup 235}U in pipes at a GCEP, and consequently increase the probability that the potential production of HEU and/or diversion of fissile material will be detected. The FEMO requires no piping penetrations and can be installed on pipes containing the flow of uranium hexafluoride (UF{sub 6}) at a GCEP. This FEMO consists of separate parts, a flow monitor (FM) and an enrichment monitor (EM). Development of the FM is primarily the responsibility of Oak Ridge National Laboratory, and development of the EM is primarily the responsibility of Los Alamos National Laboratory. The FM will measure {sup 235}U mass flow rate by combining information from measuring the UF{sub 6} volumetric flow rate and the {sup 235}U density. The UF{sub 6} flow rate will be measured using characteristics of the process pumps used in product and tail UF{sub 6} header process lines of many GCEPs, and the {sup 235}U density will be measured using commercially available sodium iodide (NaI) gamma ray scintillation detectors. This report describes the calibration of the portion of the FM that measures the {sup 235}U density. Research has been performed to define a methodology and collect data necessary to perform this calibration without the need for plant declarations. The {sup 235}U density detector is a commercially available system (GammaRad made by Amptek, www.amptek.com) that contains the NaI crystal, photomultiplier tube, signal conditioning electronics, and a multichannel analyzer (MCA). Measurements were made with the detector system installed near four {sup 235}U sources. Two of the sources were made of solid uranium, and the other two were in the form of UF{sub 6} gas in aluminum piping. One of the UF{sub 6} gas sources was located at ORNL and the other at LANL. The ORNL source consisted of two pipe sections (schedule 40 aluminum pipe of 4-inch and 8-inch outside diameter) with 5.36% {sup 235}U enrichment, and the LANL source was a 4-inch schedule 40 aluminum pipe with 3.3% {sup 235}U enrichment. The configurations of the detector on these test sources, as well as on long straight pipe configurations expected to exist at GCEPs, were modeled using the computer code MCNP. The results of the MCNP calculations were used to define geometric correction factors between the test source and the GCEP application. Using these geometric correction factors, the experimental 186 keV counts in the test geometry were extrapolated to the expected GCEP ge

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

2010-01-01

40

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

41

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

42

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

SciTech Connect

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

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

2006-07-01

43

The PBMR steady-state and coupled kinetics core thermal-hydraulics benchmark test problems  

Microsoft Academic Search

In support of the pebble bed modular reactor (PBMR) Verification and Validation (V&V) effort, a set of benchmark test problems has been defined that focus on coupled core neutronics and thermal-hydraulic code-to-code comparisons. The motivation is not only to test the existing methods or codes available for high-temperature gas-cooled reactors (HTGRs), but also to serve as a basis for the

Frederik Reitsma; Gerhard Strydom; J. B. M. de Haas; Kostadin Ivanov; Bismark Tyobeka; Ramatsemela Mphahlele; Tom Downar; Volkan Seker; Hans D Gougar; D. F. Da Cruz; U. E. Sikik

2006-01-01

44

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

SciTech Connect

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

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

2012-07-01

45

Electrical isolation problems in underground fuel storage tanks and piping  

Microsoft Academic Search

Eleven underground fuel storage tanks have been replaced at the Department of Energy`s Savannah River Site since 1986. The replacement tanks are steel tank-in-tank construction with the exterior surface coated and cathodically protected. The annular space between tanks is monitored for leaks, thus meeting current Federal and State environmental regulations. Piping connected to the tanks is also coated and cathodically

E. M. Vessel; C. F. Jenkins

1994-01-01

46

An Indirect Approach to the Three-Dimensional Multi-pipe Routing Problem  

Microsoft Academic Search

\\u000a This paper explores an indirect approach to the Three- dimensional Multi-pipe Routing problem. Variable length pipelines are\\u000a built by letting a virtual robot called a turtle navigate through space, leaving pipe segments along its route. The turtle\\u000a senses its environment and acts in accordance with commands received from heuristics currently under evaluation. The heuristics\\u000a are evolved by a Gene Expression

Marcus Furuholmen; Kyrre Glette; Mats Høvin; Jim Torresen

2010-01-01

47

Foam pigs solve pipe cleaning problems offshore Brazil  

SciTech Connect

Pipeline systems in which conventional pigs cannot be run are common in such complex offshore installations as are found in Brazil`s Campos basin. These systems may contain changing pipe diameters or wet christmas trees and manifolds. A new concept for using low cost, low-density foam pigs for both liquid removal in wet-gas pipelines and paraffin removal in oil and multiphase pipelines has been successfully tested offshore Brazil. Although the present discussion focuses on condensate and paraffin removal in pipelines, the principles can be applied to several kinds of operations including general pipeline cleaning, product removal or separation in pipeline, corrosion evaluation, and chemical product application.

Lima, P.C.R.; Neto, S.J.A. [Petroleo Brasileiro S.A., Rio de Janeiro (Brazil)

1995-10-02

48

An improved transmission line matrix model for the 2D ideal wedge benchmark problem  

NASA Astrophysics Data System (ADS)

The numerical modelling of acoustic propagation in underwater environments using transmission line matrix (TLM) has received little attention for some time. This has been due, in part, to the need for an open boundary description, also known as a ‘perfectly matched load’ or PML, and the requirement for an accurate description of non-uniform bounding walls. The first of these problems has been solved by many researchers in subsequent years. The paper describes a novel solution to the second problem, allowing the incorporation of boundary-conforming Cartesian meshes into TLM schemes for acoustic propagation. This and a related technique are compared using the Buckingham and Tolstoy ideal 2D wedge benchmark test.

Scott, I. J. G.; de Cogan, D.

2008-04-01

49

Improving the worthiness of the Henry problem as a benchmark for density-dependent groundwater flow models  

Microsoft Academic Search

This study considers the worthiness of the Henry saltwater intrusion problem as a test case to benchmark density-dependent groundwater flow models. Previously published results from a coupled versus uncoupled analysis indicate that the flow patterns associated with the standard Henry problem are largely dictated by the boundary forcing and not necessarily a result of density-dependent effects [Simpson and Clement, 2003].

Matthew J. Simpson; T. Prabhakar Clement

2004-01-01

50

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

SciTech Connect

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

Winters, W.S.

1985-10-01

51

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.

52

Dependability Benchmarking: making choices in an n-dimensional problem space  

Microsoft Academic Search

Dependability benchmarks should provide cost- effective ways to evaluate the behavior of components and computer systems in the presence of faults, allowing the quantification of dependability attributes or the characterization of the systems into well defined dependability classes. Beyond existing evaluation techniques, a dependability benchmark should represent an agreement accepted by the computer industry or\\/and by the user community, and

Henrique Madeira; Philip Koopman

2001-01-01

53

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

54

Results from the multi-species benchmark problem (BM3) using one-dimensional models.  

PubMed

The IWA's Biofilm Modeling Task Group created a multi-species benchmark problem in which heterotrophic bacteria, nitrifying bacteria, and inert biomass coexist in a biofilm. Members of the Task Group submitted solutions from nine different one-dimensional models. The most important distinctions among the models were (1) whether the model required a full numerical solution or was solved with a spreadsheet, and (2) the way the biomass types were distributed in the biofilm. The models that protected the slow-growing species by having them accumulate away from the outer surface always had the largest surface coverage by nitrifiers and inerts, but the heterotroph coverage declined to compensate. Coverage by heterotrophs and removal of substrate COD were most strongly affected by dilution from nitrifiers and inerts near the outer surface. Models that did not allow the nitrifiers and inerts to dilute the heterotrophs significantly in the outer layer predicted more removal of COD than did the other models. The choice of the model to use depends on the user's needs and the relative importance of including protection of slow-growing species and/or dilution of fast-growing species. PMID:15303737

Rittmann, B E; Schwarz, A O; Eberl, H J; Morgenroth, E; Perez, J; van Loosdrecht, M; Wanner, Oskar

2004-01-01

55

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

56

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

57

Application of the INSTANT-HPS PN Transport Code to the C5G7 Benchmark Problem  

SciTech Connect

INSTANT is the INL's next generation neutron transport solver to support high-fidelity multi-physics reactor simulation INSTANT is in continuous development to extend its capability Code is designed to take full advantage of middle to large cluster (10-1000 processors) Code is designed to focus on method adaptation while also mesh adaptation will be possible. It utilizes the most modern computing techniques to generate a neutronics tool of full-core transport calculations for reactor analysis and design. It can perform calculations on unstructured 2D/3D triangular, hexagonal and Cartesian geometries. Calculations can be easily extended to more geometries because of the independent mesh framework coded with the model Fortran. This code has a multigroup solver with thermal rebalance and Chebyshev acceleration. It employs second-order PN and Hybrid Finite Element method (PNHFEM) discretization scheme. Three different in-group solvers - preconditioned Conjugate Gradient (CG) method, preconditioned Generalized Minimal Residual Method (GMRES) and Red-Black iteration - have been implemented and parallelized with the spatial domain decomposition in the code. The input is managed with extensible markup language (XML) format. 3D variables including the flux distributions are outputted into VTK files, which can be visualized by tools such as VisIt and ParaView. An extension of the code named INSTANTHPS provides the capability to perform 3D heterogeneous transport calculations within fuel pins. C5G7 is an OECD/NEA benchmark problem created to test the ability of modern deterministic transport methods and codes to treat reactor core problems without spatial homogenization. This benchmark problem had been widely analyzed with various code packages. In this transaction, results of the applying the INSTANT-HPS code to the C5G7 problem are summarized.

Y. Wang; H. Zhang; R. H. Szilard; R. C. Martineau

2011-06-01

58

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

59

Research Reactor Benchmarks  

SciTech Connect

A criticality benchmark experiment performed at the Jozef Stefan Institute TRIGA Mark II research reactor is described. This experiment and its evaluation are given as examples of benchmark experiments at research reactors. For this reason the differences and possible problems compared to other benchmark experiments are particularly emphasized. General guidelines for performing criticality benchmarks in research reactors are given. The criticality benchmark experiment was performed in a normal operating reactor core using commercially available fresh 20% enriched fuel elements containing 12 wt% uranium in uranium-zirconium hydride fuel material. Experimental conditions to minimize experimental errors and to enhance computer modeling accuracy are described. Uncertainties in multiplication factor due to fuel composition and geometry data are analyzed by sensitivity analysis. The simplifications in the benchmark model compared to the actual geometry are evaluated. Sample benchmark calculations with the MCNP and KENO Monte Carlo codes are given.

Ravnik, Matjaz; Jeraj, Robert [J. Stefan Institute (Slovenia)

2003-09-15

60

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

61

Differential evolution with ensemble of constraint handling techniques for solving CEC 2010 benchmark problems  

Microsoft Academic Search

Several constraint handling techniques have been proposed to be used with the evolutionary algorithms (EAs). According to the no free lunch theorem, it is impossible for a single constraint handling technique to outperform all other techniques on every problem. In other words, depending on several factors such as the ratio between feasible search space and the whole search space, multi-modality

Rammohan Mallipeddi; Ponnuthurai Nagaratnam Suganthan

2010-01-01

62

Diagnosis of timed automata: Theory and application to the DAMADICS actuator benchmark problem  

Microsoft Academic Search

This paper concerns the problem of fault diagnosis in discrete-event systems which are represented by timed automata. The diagnostic algorithm for timed automata detects and identifies faults in the system based on the investigation whether the measured input and output sequences are consistent with the timed automaton. This diagnostic approach can be applied spontaneously to the discrete-event system since no

P. Supavatanakul; J. Lunze; V. Puig; J. Quevedo

2006-01-01

63

Numerical and Analytical Solutions to Benchmark Problems Related to Tunnel Mechanics.  

National Technical Information Service (NTIS)

In this report, five numerical approaches to problems of tunnel dynamics are compared with each other and--wherever possible--with exact analytic solutions. The medium is an idealization of a jointed rock mass. The intact rock is linear elastic-plastic wi...

D. A. Simons

1993-01-01

64

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

EPA Science Inventory

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

65

Fully implicit solutions of the benchmark backward facing step problem using finite element discretization and inexact Newton's method  

SciTech Connect

A fully implicit solution algorithm based on Newton's method is used to solve the steady, incompressible Navier-Stokes and energy equations. An efficiently evaluated numerical Jacobian is used to simplify implementation, and mesh sequencing is used to increase the radius of convergence of the algorithm. We employ finite volume discretization using the power law scheme of Patankar to solve the benchmark backward facing step problem defined by the ASME K-12 Aerospace Heat Transfer Committee. LINPACK banded Gaussian elimination and the preconditioned transpose-free quasi-minimal residual (TFQMR) algorithm of Freund are studied as possible linear equation solvers. Implementation of the preconditioned TFQMR algorithm requires use of the switched evolution relaxation algorithm of Mulder and Van Leer to ensure convergence. The preconditioned TFQMR algorithm is more memory efficient than the direct solver, but our implementation is not as CPU efficient. Results show that for the level of grid refinement used, power law differencing was not adequate to yield the desired accuracy for this problem.

McHugh, P.R.; Knoll, D.A.

1992-01-01

66

Fully implicit solutions of the benchmark backward facing step problem using finite element discretization and inexact Newton`s method  

SciTech Connect

A fully implicit solution algorithm based on Newton`s method is used to solve the steady, incompressible Navier-Stokes and energy equations. An efficiently evaluated numerical Jacobian is used to simplify implementation, and mesh sequencing is used to increase the radius of convergence of the algorithm. We employ finite volume discretization using the power law scheme of Patankar to solve the benchmark backward facing step problem defined by the ASME K-12 Aerospace Heat Transfer Committee. LINPACK banded Gaussian elimination and the preconditioned transpose-free quasi-minimal residual (TFQMR) algorithm of Freund are studied as possible linear equation solvers. Implementation of the preconditioned TFQMR algorithm requires use of the switched evolution relaxation algorithm of Mulder and Van Leer to ensure convergence. The preconditioned TFQMR algorithm is more memory efficient than the direct solver, but our implementation is not as CPU efficient. Results show that for the level of grid refinement used, power law differencing was not adequate to yield the desired accuracy for this problem.

McHugh, P.R.; Knoll, D.A.

1992-12-31

67

The canonical problem of the fluid-conveying pipe and radiation of the knowledge gained to other dynamics problems across Applied Mechanics  

NASA Astrophysics Data System (ADS)

The basic dynamics of pipes conveying fluid is reviewed, establishing why this system has become a model dynamical problem. The paper then discusses the radiation of the experience gained in studying this problem into other areas of Applied Mechanics, particularly other problems in fluid structure interactions involving slender structures and axial flows; specifically the dynamics of (i) quasi-cylindrical bodies in axial flow or towed in quiescent fluid; (ii) cylindrical shells containing or immersed in axial flow; and (iii) plates in axial flow. Applications, some of them wholly unexpected when the work was done, are noted throughout.

Pa??doussis, M. P.

2008-02-01

68

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

69

ENDF/B-V and ENDF/B-VI results for UO{sub 2} lattice benchmark problems using MCNP  

SciTech Connect

Calculations for the ANS UO{sub 2} lattice benchmark have been performed with the MCNP Monte Carlo code and its ENDF/B-V and ENDF/B-VI continuous-energy libraries. The ENDF/B-V library produces significantly better agreement with the benchmark value for k{sub eff} than do the ENDF/B-VI libraries. However, the pin power distributions are essentially the same irrespective of the library.

Mosteller, R.D.

1998-12-31

70

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

71

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

ERIC Educational Resources Information Center

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

Engel, Renata S.; And Others

1996-01-01

72

Assumed-strain solid–shell formulation for the six-node finite element SHB6: evaluation on non-linear benchmark problems  

Microsoft Academic Search

The current contribution proposes a six-node prismatic solid–shell denoted as (SHB6). The formulation is extended to geometric and material non-linearities, and focus will be placed on its validation on non-linear benchmark problems. The resulting derivation only involves displacement DOF, as it is based on a fully 3D approach. The motivation behind this is to allow a natural mesh connexion in

Farid Abed-Meraim; Vuong-Dieu Trinh; Alain Combescure

2012-01-01

73

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

74

A Comparative Performance of Swarm Intelligence Optimization Method and Evolutionary Optimization Method on Some Noisy Numerical Benchmark Test Problems  

Microsoft Academic Search

Recently many algorithms have been developed which mimics the natural procedure better known as Evolutionary Algorithm and claims to perform better than others. The objective of this paper is to test the performance of Genetic algorithm and Repulsive Particle Swarm method on some benchmark functions. Since GA(Genetic Algorithm) mimics the nature and (RPS) exploits the swarm intelligence, it will be

Sanjeev Kumar Singh; Munindra Borah

75

ENDF/B-V and ENDF/B-VI results for UO-2 lattice benchmark problems using MCNP  

SciTech Connect

Calculations for the ANS UO{sub 2} lattice benchmark have been performed with the MCNP Monte Carlo code and its ENDF/B-V and EnDF/B-VI continuous-energy libraries. Similar calculations were performed previously for the experiments upon which these benchmarks are based, using continuous-energy libraries derived from EnDF/B-V and from Release 2 of EnDF/B-VI (ENDF/B-VI.2). This study extends those calculations to the infinite-lattice configurations given in the benchmark specifications and also includes results from Release 3 of EnDF/B-VI (ENDF/B-VI.3) for both the core and infinite-lattice configurations. For this set of benchmarks, the only significant difference between the ENDF/B-VI.2 and EnDF/B-VI.3 libraries is the cross-section behavior of {sup 235}U. EnDF/B-VI.3 contains revised cross sections for {sup 235}U below 900 eV, although those changes principally affect the range below 110 eV. In particular, relative to EnDF/B-VI.2, EnDF/B-VI.3 increases the epithermal capture-to-fission ratio for {sup 235}U and slightly increases its thermal fission cross section.

Mosteller, R.D.

1998-08-01

76

Inspecting flexible pipe  

SciTech Connect

Principal modes of failure as well as defects which cause leakage or cross-section damage are discussed. The author explains in detail how traditional problems associated with inspecting flexible pipe, which include discriminating between pipe layers, corrosion monitoring and the use of intelligent pigs, can be related to flexible pipe's complex construction and complex behavior. Proper pig selection and operations are emphasized.

Neffgen, J.M. (Pag-O-Flex, AS (NO))

1990-12-01

77

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

78

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

79

Benchmarking: A Process for Improvement.  

ERIC Educational Resources Information Center

|One problem with the outcome-based measures used in higher education is that they measure quantity but not quality. Benchmarking, or the use of some external standard of quality to measure tasks, processes, and outputs, is partially solving that difficulty. Benchmarking allows for the establishment of a systematic process to indicate if outputs…

Peischl, Thomas M.

80

The constant flow rate problem for fluids with increasing yield stress in a pipe  

NASA Astrophysics Data System (ADS)

Experiments show that the degradation effect observed during both stirring and pipelining tests of some coal-water slurries is mainly to be ascribed to the increase of the yield stress. Regardless of the particular mathematical model adopted to investigate the dynamics of these fluids, engineering applications force us to consider the problem of how long a constant flow rate can be maintained during the pipelining process. We choose a Bingham model where the yield stress is assumed to increase with the dissipated energy as in [5]. It is first shown that the constant flow rate problem is equivalent to solving a nonlinear functional equation in the unknown pressure gradient that generalizes the classical algebraic Buckingham equation for the same problem with constant rheological parameters. By means of a fixed-point argument we also prove that the functional equation has one and only one solution which is local in time. We finally find an estimate from below of the interval of the interval of existence. Numerical results are rather good and agree with those expected from the engineering point of view.

Gianni, R.; Pezza, L.; Rosso, F.

1995-11-01

81

The evaluation of erosion\\/corrosion problems of carbon steel piping in Taiwan PWR nuclear power plant  

Microsoft Academic Search

Taiwan Pressurized Water Reactor (PWR), Maanshan nuclear power plant Units 1 and 2 implemented measurements of the wall thinning of the carbon steel piping under the request of regulation authority to prevent the events due to erosion\\/corrosion since 1989. At first, the licensee established the comprehensive inspection program by itself. Over 2000 components were inspected per unit and 300–500 pipe

Kuen Ting; Yin Pang Ma

1999-01-01

82

The DaCapo benchmarks: java benchmarking development and analysis  

Microsoft Academic Search

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

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

2006-01-01

83

Modelling a spatially heterogeneous biofilm and the bulk fluid: selected results from benchmark problem 2 (BM2).  

PubMed

The numerical simulation of mass transfer and conversion in spatially heterogeneous biofilms on the meso-scale requires an accurate description of the hydrodynamics in the biofilm systems and of spatial effects. This leads to systems of three-dimensional nonlinear partial differential equations that are numerically very expensive to solve and to data requirements that are not easy to meet. In this paper several modeling approaches to reduce the physical complexity and, hence, accelerate the computation are compared. They range from a mere reduction of dimensionality by lumping the problem along a secondary flow direction to global mass balances or empirical correlations, at the core of which a one-dimensional boundary value problem must be solved. It is found that even strongly simplified models can describe the qualitative behaviour of the model with regard to variations in the geometrical and hydrodynamic model parameters quite well. In order to obtain also quantitatively reliable results the hydrodynamics must be considered in an appropriate manner. PMID:15303736

Eberl, H J; van Loosdrecht, M C M; Morgenroth, E; Noguera, D R; Perez, J; Picioreanu, C; Rittmann, B E; Schwarz, A O; Wanner, O

2004-01-01

84

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

85

Benchmarking Query Execution Robustness  

NASA Astrophysics Data System (ADS)

Benchmarks that focus on running queries on a well-tuned database system ignore a long-standing problem: adverse runtime conditions can cause database system performance to vary widely and unexpectedly. When the query execution engine does not exhibit resilience to these adverse conditions, addressing the resultant performance problems can contribute significantly to the total cost of ownership for a database system in over-provisioning, lost efficiency, and increased human administrative costs. For example, focused human effort may be needed to manually invoke workload management actions or fine-tune the optimization of specific queries.

Wiener, Janet L.; Kuno, Harumi; Graefe, Goetz

86

Pipe support  

DOEpatents

A pipe support for high temperature, thin-walled piping runs such as those used in nuclear systems. A section of the pipe to be supported is encircled by a tubular inner member comprised of two walls with an annular space therebetween. Compacted load-bearing thermal insulation is encapsulated within the annular space, and the inner member is clamped to the pipe by a constant clamping force split-ring clamp. The clamp may be connected to pipe hangers which provide desired support for the pipe.

Pollono, Louis P. (Hempfield Township, Hempfield County, PA)

1979-01-01

87

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

88

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

89

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

90

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

91

Benchmarking for large-scale placement and beyond  

Microsoft Academic Search

Over the last five years, the large scale integrated circuit placement community achieved great strides in the understanding of placement problems, developed new high-performance algorithms, and achieved impressive empirical results. These advances have been supported by a nontrivial benchmarking infrastructure, and future achievements are set to draw on benchmarking as well. In this paper, we review motivations for benchmarking, especially

Saurabh N. Adya; Mehmet Can Yildiz; Igor L. Markov; Paul G. Villarrubia; Phiroze N. Parakh; Patrick H. Madden

2004-01-01

92

Shielding benchmark tests of JENDL-3.  

National Technical Information Service (NTIS)

The integral test of neutron cross sections for major shielding materials in JENDL-3 has been performed by analyzing various shielding benchmark experiments. For the fission-like neutron source problem, the following experiments are analyzed: (1) ORNL Bro...

M. Kawai A. Hasegawa K. Ueki N. Yamano K. Sasaki

1994-01-01

93

Benchmarking in Foodservice Operations.  

National Technical Information Service (NTIS)

The objective of this study was to identify usage of foodservice performance measures, important activities in foodservice benchmarking, and benchmarking attitudes, beliefs, and practices by foodservice directors. The design of this study included two par...

B. C. Johnson

1998-01-01

94

PNNL Information Technology Benchmarking  

SciTech Connect

This document describes the Pacific Northwest National Laboratory's (PNNL's) approach to information technology (IT) benchmarking. The purpose is to engage other organizations in the collaborative process of benchmarking in order to improve the value of IT services provided to customers. This document's intended audience consists of other U. S. Department of Energy (DOE) national laboratories and their IT staff. Although the individual participants must define the scope of collaborative benchmarking, an outline of IT service areas for possible benchmarking is described.

Hostetler, David D.; Goolsbey, Jan E.; Niesen, David A.; Phillips, Anita C.

1999-08-09

95

High temperature heat pipe experiments aboard the space shuttle  

SciTech Connect

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

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

1993-01-10

96

Benchmark selection considerations.  

PubMed

Benchmarking with other organizations is an important component in achieving best practice and the highest level of quality patient care. When more than 1 benchmark exists for the same metric, choosing which one to use can be challenging. Considerations are discussed for the selection of the best benchmark to use to ensure that an organization is striving for top performance. PMID:22504885

Rees, Susan; Leahy-Gross, Kristine

97

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.

98

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

99

Pipe Gripper.  

National Technical Information Service (NTIS)

The patent application relates to a device for gripping the exterior surface of a pipe or rod which has a plurality of wedges, each having a concave face which engages the outer surface of the pipe and each having a smooth face opposing the concave face. ...

S. M. Moyers

1974-01-01

100

Laminar convective heat transfer of a Bingham plastic in a circular pipe—I. Analytical approach—thermally fully developed flow and thermally developing flow (the Graetz problem extended)  

Microsoft Academic Search

Thermally fully developed and thermally developing laminar flows of a Bingham plastic in a circular pipe have been studied analytically. For thermally fully developed flow, the Nusselt numbers and temperature profiles are presented in terms of the yield stress and Peclet number, proposing a correlation formula between the Nusselt number and the Peclet number. The solution to the Graetz problem

Taegee Min; Jung Yul Yoo; Haecheon Choi

1997-01-01

101

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

102

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

103

High temperature heat pipe experiments in low earth orbit  

SciTech Connect

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

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

1993-02-01

104

High temperature heat pipe experiments in low earth orbit  

SciTech Connect

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

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

1993-01-01

105

A heuristic for piping residential sprinklers  

Microsoft Academic Search

A heuristic developed in this study derives efficient pipe configurations for connecting sprinklers. The objective is to connect all of the sprinkers in a watering zone with a minimum length of pipe. Minimum-length pipe configurations reduce pressure loss and installation cost. The heuristic adapts the Prim algorithm, conventionally used to derive minimal spanning trees, to a modified rectilinear Steiner problem.

Paul F. Hudak

1996-01-01

106

Corrosion of Copper Pipes  

Microsoft Academic Search

Rapid pitting of the walls of copper pipes used in plumbing has resulted in several controversial overtones. The results of a study of the problem in southern California are now available in this article and should benefit the water purveyor, who is, after all, responsible for taking reasonable measures to prevent unnecessary corrosion to copper service lines

Henry Cruse; Richard D. Pomeroy

1974-01-01

107

Heat pipe heat exchanger design considerations  

Microsoft Academic Search

Typical heat pipe heat exchangers (HPHX) are described, along with their advantages, uses, and some problems in HPHX design, and a computer HPHX analysis program is discussed with required input data. The computer program is being developed for analysis of heat exchange performance by finned-tube HPHX and thread-puddle-artery heat pipes. Copper-water heat pipes and carbon steel-Dowtherm A heat pipes are

K. T. Feldman; D. C. Lu

1976-01-01

108

IAEA sodium void reactivity benchmark calculations  

SciTech Connect

In this paper, the IAEA-1 992 ``Benchmark Calculation of Sodium Void Reactivity Effect in Fast Reactor Core`` problem is evaluated. The proposed design is a large axially heterogeneous oxide-fueled fast reactor as described in Section 2; the core utilizes a sodium plenum above the core to enhance leakage effects. The calculation methods used in this benchmark evaluation are described in Section 3. In Section 4, the calculated core performance results for the benchmark reactor model are presented; and in Section 5, the influence of steel and interstitial sodium heterogeneity effects is estimated.

Hill, R.N.; Finck, P.J.

1992-12-01

109

IAEA sodium void reactivity benchmark calculations  

SciTech Connect

In this paper, the IAEA-1 992 Benchmark Calculation of Sodium Void Reactivity Effect in Fast Reactor Core'' problem is evaluated. The proposed design is a large axially heterogeneous oxide-fueled fast reactor as described in Section 2; the core utilizes a sodium plenum above the core to enhance leakage effects. The calculation methods used in this benchmark evaluation are described in Section 3. In Section 4, the calculated core performance results for the benchmark reactor model are presented; and in Section 5, the influence of steel and interstitial sodium heterogeneity effects is estimated.

Hill, R.N.; Finck, P.J.

1992-01-01

110

PRISMATIC CORE COUPLED TRANSIENT BENCHMARK  

SciTech Connect

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

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

2011-06-01

111

Large-bore pipe decontamination  

SciTech Connect

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

Ebadian, M.A.

1998-01-01

112

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

113

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

114

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

115

Acoustics as applied to leak detection and pipe location  

SciTech Connect

This paper gives a brief overview of the application of acoustics to the gas industry problems of leak and pipe location. Active and passive sonic leak location are briefly described. Two approaches to acoustic pipe location, acoustic radar'' or pulse echo and active sonic pipe location, are discussed. The active sonic technique is very promising for plastic pipe location. 18 refs.

Huebler, J.E.; Campbell, B.K.

1990-01-01

116

Benchmarking short sequence mapping tools  

PubMed Central

Background The development of next-generation sequencing instruments has led to the generation of millions of short sequences in a single run. The process of aligning these reads to a reference genome is time consuming and demands the development of fast and accurate alignment tools. However, the current proposed tools make different compromises between the accuracy and the speed of mapping. Moreover, many important aspects are overlooked while comparing the performance of a newly developed tool to the state of the art. Therefore, there is a need for an objective evaluation method that covers all the aspects. In this work, we introduce a benchmarking suite to extensively analyze sequencing tools with respect to various aspects and provide an objective comparison. Results We applied our benchmarking tests on 9 well known mapping tools, namely, Bowtie, Bowtie2, BWA, SOAP2, MAQ, RMAP, GSNAP, Novoalign, and mrsFAST (mrFAST) using synthetic data and real RNA-Seq data. MAQ and RMAP are based on building hash tables for the reads, whereas the remaining tools are based on indexing the reference genome. The benchmarking tests reveal the strengths and weaknesses of each tool. The results show that no single tool outperforms all others in all metrics. However, Bowtie maintained the best throughput for most of the tests while BWA performed better for longer read lengths. The benchmarking tests are not restricted to the mentioned tools and can be further applied to others. Conclusion The mapping process is still a hard problem that is affected by many factors. In this work, we provided a benchmarking suite that reveals and evaluates the different factors affecting the mapping process. Still, there is no tool that outperforms all of the others in all the tests. Therefore, the end user should clearly specify his needs in order to choose the tool that provides the best results.

2013-01-01

117

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

Microsoft Academic Search

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

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

2010-01-01

118

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

119

PNNL Information Technology Benchmarking  

Microsoft Academic Search

This document describes the Pacific Northwest National Laboratory's (PNNL's) approach to information technology (IT) benchmarking. The purpose is to engage other organizations in the collaborative process of benchmarking in order to improve the value of IT services provided to customers. This document's intended audience consists of other U. S. Department of Energy (DOE) national laboratories and their IT staff. Although

David D. Hostetler; Jan E. Goolsbey; David A. Niesen; Anita C. Phillips

1999-01-01

120

Numerical methods: Analytical benchmarking in transport theory  

SciTech Connect

Numerical methods applied to reactor technology have reached a high degree of maturity. Certainly one- and two-dimensional neutron transport calculations have become routine, with several programs available on personal computer and the most widely used programs adapted to workstation and minicomputer computational environments. With the introduction of massive parallelism and as experience with multitasking increases, even more improvement in the development of transport algorithms can be expected. Benchmarking an algorithm is usually not a very pleasant experience for the code developer. Proper algorithmic verification by benchmarking involves the following considerations: (1) conservation of particles, (2) confirmation of intuitive physical behavior, and (3) reproduction of analytical benchmark results. By using today's computational advantages, new basic numerical methods have been developed that allow a wider class of benchmark problems to be considered.

Ganapol, B.D. (Univ. of Arizona, Tucson (USA))

1988-01-01

121

Benchmarking massively parallel architectures  

SciTech Connect

The purpose of this paper is to summarize some initial experiences related to measuring the performance of massively parallel processors (MPPs) at Los Alamos National Laboratory (LANL). Actually, the range of MPP architectures the authors have used is rather limited, being confined mostly to the Thinking Machines Corporation (TMC) Connection Machine CM-2 and CM-5. Some very preliminary work has been carried out on the Kendall Square KSR-1, and efforts related to other machines, such as the Intel Paragon and the soon-to-be-released CRAY T3D are planned. This paper will concentrate more on methodology rather than discuss specific architectural strengths and weaknesses; the latter is expected to be the subject of future reports. MPP benchmarking is a field in critical need of structure and definition. As the authors have stated previously, such machines have enormous potential, and there is certainly a dire need for orders of magnitude computational power over current supercomputers. However, performance reports for MPPs must emphasize actual sustainable performance from real applications in a careful, responsible manner. Such has not always been the case. A recent paper has described in some detail, the problem of potentially misleading performance reporting in the parallel scientific computing field. Thus, in this paper, the authors briefly offer a few general ideas on MPP performance analysis.

Lubeck, O.; Moore, J.; Simmons, M.; Wasserman, H.

1993-07-01

122

Benchmarking massively parallel architectures  

SciTech Connect

The purpose of this paper is to summarize some initial experiences related to measuring the performance of massively parallel processors (MPPs) at Los Alamos National Laboratory (LANL). Actually, the range of MPP architectures the authors have used is rather limited, being confined mostly to the Thinking Machines Corporation (TMC) Connection Machine CM-2 and CM-5. Some very preliminary work has been carried out on the Kendall Square KSR-1, and efforts related to other machines, such as the Intel Paragon and the soon-to-be-released CRAY T3D are planned. This paper will concentrate more on methodology rather than discuss specific architectural strengths and weaknesses; the latter is expected to be the subject of future reports. MPP benchmarking is a field in critical need of structure and definition. As the authors have stated previously, such machines have enormous potential, and there is certainly a dire need for orders of magnitude computational power over current supercomputers. However, performance reports for MPPs must emphasize actual sustainable performance from real applications in a careful, responsible manner. Such has not always been the case. A recent paper has described in some detail, the problem of potentially misleading performance reporting in the parallel scientific computing field. Thus, in this paper, the authors briefly offer a few general ideas on MPP performance analysis.

Lubeck, O.; Moore, J.; Simmons, M.; Wasserman, H.

1993-01-01

123

Benchmarked Comparison of the TSS/360, CP/67, MTS and OS/MVT Computer Operating Systems.  

National Technical Information Service (NTIS)

A set of terminal scripts and benchmarks have been derived for comparing the performance of time sharing and batch computer operating systems. Some of the problems encountered in designing valid benchmarks for comparing computer operating systems under bo...

G. H. Syms

1973-01-01

124

Benchmarking and the laboratory  

PubMed Central

This article describes how benchmarking can be used to assess laboratory performance. Two benchmarking schemes are reviewed, the Clinical Benchmarking Company's Pathology Report and the College of American Pathologists' Q-Probes scheme. The Clinical Benchmarking Company's Pathology Report is undertaken by staff based in the clinical management unit, Keele University with appropriate input from the professional organisations within pathology. Five annual reports have now been completed. Each report is a detailed analysis of 10 areas of laboratory performance. In this review, particular attention is focused on the areas of quality, productivity, variation in clinical practice, skill mix, and working hours. The Q-Probes scheme is part of the College of American Pathologists programme in studies of quality assurance. The Q-Probes scheme and its applicability to pathology in the UK is illustrated by reviewing two recent Q-Probe studies: routine outpatient test turnaround time and outpatient test order accuracy. The Q-Probes scheme is somewhat limited by the small number of UK laboratories that have participated. In conclusion, as a result of the government's policy in the UK, benchmarking is here to stay. Benchmarking schemes described in this article are one way in which pathologists can demonstrate that they are providing a cost effective and high quality service. Key Words: benchmarking • pathology

Galloway, M; Nadin, L

2001-01-01

125

Piping geofluids  

Microsoft Academic Search

In many cases the source of geothermal fluid to be used for a direct use application is located some distance away from the user. This requires a transmission pipeline to transport the geothermal fluid. Even in the absence of transmission line requirements it is frequently advisable to employ other than standard piping materials. Geothermal energy for direct use applications is

P. J. Lienau; K. Rafferty

2009-01-01

126

Development of a Magnetic Coating for Gas Pipe Detection. Final Report May 1987-June 1988,  

National Technical Information Service (NTIS)

The inability to accurately locate plastic gas pipe after it is buried has been a troublesome problem since plastic pipe began being used for natural gas distribution. Electromagnetic pipe locaters have been available to the gas industry for decades. Howe...

W. L. Goodman

1989-01-01

127

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

128

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

129

Ultrasonic testing technique for small-calibre piping containing defects  

Microsoft Academic Search

An effective method of ultrasonic testing was developed for inspecting the quality of weld seams for small-calibre, thin-walled pipes. The basic technical problems encountered in measuring the height of defects in the piping by an ultrasonic testing method were analyzed and studied experimentally. To overcome these problems, two small probes with special cylindrical contact surfaces, and five types of piping

J. Singletary

1996-01-01

130

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

SciTech Connect

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

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

1980-06-01

131

Neural network benchmark  

NASA Astrophysics Data System (ADS)

In this paper, we will present a Neural Net Benchmark. In many neural algorithms, learning is defined as a change in connection weight values that result in the capture of training information that can later be recalled. A typical learning algorithm is: if neuron A was active and A's activity caused a connected neuron B to fire, then the synaptic connection between A and B should be increased by certain amount. The benchmark systematically tests a neural network for this ability. The benchmark can be written as: (L3, L4, L5, L6, ... ...). L3 tests the net's ability for 3- neuron correlation: if A and B were active and A and B's activity caused a connected neuron C to fire, can the network recall it later? Similarly, L4, L5, ... tests a net for 4-neuron, 5-neuron correlation. We will also present a neural net classification based on the benchmark.

Liu, Ying

1997-04-01

132

TWODANT benchmark. Progress report  

SciTech Connect

TWODANT (Two-Dimensional, Diffusion-Accelerated, Neutral-Particle Transport) code has been benchmarked against 6 critical experiments (Jezebel plutonium critical assembly) and their k effective values compared with those of KENO and MCNP codes.

Lee, Sung [Arizona Univ., Tucson, AZ (United States)

1994-01-11

133

Benchmarking: Graphics Workstations.  

National Technical Information Service (NTIS)

This paper reports on work being performed to benchmark a new breed of machines, the graphics workstations for scientific and engineering applications. We begin with the history of workstations and how they developed. Many different forces created the gra...

B. E. Brown R. L. Judd

1985-01-01

134

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

135

Toxicological Benchmarks for Wildlife  

Microsoft Academic Search

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

B. E. Opresko; D. M. Suter

1993-01-01

136

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

137

Automatic Generation of Versatile Benchmarks for Parallel Production System Architectures  

Microsoft Academic Search

The shortage of adequate benchmarking facilities is a major problem in the proper evaluationof production system machine organizations. This paper presents a new benchmarkproblem that allows independent variations in the size of the database, the number of productions,the ratio between local and global data, and the variance in the size of local dataclusters. This benchmark, available via the Internet through

Jos'e Nelson Amaral; Joydeep Ghosh

138

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

139

A benchmark solution for 2D Stokes flow over cavity  

NASA Astrophysics Data System (ADS)

Two-dimensional Stokes flow in a half plane with coupled cavity having the form of semi-ellipse is considered. The exact solution for the boundary problem is obtained. The solution can be a benchmark for numerical approaches. An example of the benchmarking is given.

Popov, Igor Yu.; Makeev, Ilya V.

2013-09-01

140

Curriculum Benchmarking: A Tool for School Improvement.  

ERIC Educational Resources Information Center

Curriculum auditing is a quality-control process. If a course is not meeting expectations, is not serving students, or needs adjustment, the Roanoke Valley (Virginia) Governor's School for Science and Technology employs benchmarking to attain data to fix the problem or move in another direction. (MLH)

Shelly, Richard W.

2000-01-01

141

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

142

The effect of white or grey PVC pipe and its joint solvents (primer and cement) on odour problems in drinking water distribution systems.  

PubMed

A study of the production of odour-causing compounds was conducted from the leaching of polyvinylchloride (PVC) pipe and its joints, primer and cement, into drinking water distribution systems. Flavour Profile Analysis (FPA), closed-loop stripping analysis--gas chromatography/mass spectrometry (CLSA-GC/MS) and sensory-GC analysis of white or grey PVC alone found no odour-causing compounds produced during the leaching experiments. FPA analysis of the PVC's primer and cement leached alone and/or when applied to grey or white PVC pipes produced a glue/varnish odour. A sweet/phenolic odour replaced the glue/varnish odour after the leached media were diluted with Milli-Q water to threshold odour intensity. Three compounds were responsible for the sweet/phenolic odour and were observed by sensoryGC analysis. The leaching study of the PVC pipe with its joint solvents (primer and cement) concluded that the original solvent compounds, and their reaction products that formed during the bonding process on the PVC pipe, were a primary source of the glue/varnish odour. The original compounds of the PVC primer and cement were not detected by CLSA-GC/MS, due to their high volatility during the CLSA extraction method and/or these compounds appeared in a solvent peak of the GC/MS analysis. However, the original primer and cement chemicals (acetone, tetrahydrofuran, methyl ethyl ketone, and cyclohexanone) had a glue/varnish odour. A total of nine odorous GC peaks were produced as reaction products from leaching of primer in water and white or grey PVC pipe with primer and cement, and white or grey PVC with primer only. None of these compounds were among the chemical ingredients in the original primer or cement. Four GC peaks with a sweet/phenolic odour were present due to the reaction products of the cement leached with white or grey PVC. None of these compounds were positively identified. PMID:17489407

Wiesenthal, K E; Suffet, I H

2007-01-01

143

Design and off design pipe network geothermal power plant analysis with power pipe simulator  

Microsoft Academic Search

One of the biggest problems when analysing pipe network behaviour is the difficulty in accounting for the actual components features, as some conditions change in relation to the designed one. This problem occurs, for example, when some power machines, like turbines or pumps, are connected to the pipes. In fact, for these devices, one flow rate value corresponds to each

Francesco Di Maria

2000-01-01

144

PNNL Information Technology Benchmarking  

SciTech Connect

Benchmarking is a methodology for searching out industry best practices that lead to superior performance. It is exchanging information, not just with any organization, but with organizations known to be the best within PNNL, in industry, or in dissimilar industries with equivalent functions. It is used as a continuous improvement tool for business and technical processes, products, and services. Information technology--comprising all computer and electronic communication products and services--underpins the development and/or delivery of many PNNL products and services. This document describes the Pacific Northwest National Laboratory's (PNNL's) approach to information technology (IT) benchmarking. The purpose is to engage other organizations in the collaborative process of benchmarking in order to improve the value of IT services provided to customers. TM document's intended audience consists of other US Department of Energy (DOE) national laboratories and their IT staff. Although the individual participants must define the scope of collaborative benchmarking, an outline of IT service areas for possible benchmarking is described.

DD Hostetler

1999-09-08

145

Shielding Benchmark Computational Analysis  

SciTech Connect

Over the past several decades, nuclear science has relied on experimental research to verify and validate information about shielding nuclear radiation for a variety of applications. These benchmarks are compared with results from computer code models and are useful for the development of more accurate cross-section libraries, computer code development of radiation transport modeling, and building accurate tests for miniature shielding mockups of new nuclear facilities. When documenting measurements, one must describe many parts of the experimental results to allow a complete computational analysis. Both old and new benchmark experiments, by any definition, must provide a sound basis for modeling more complex geometries required for quality assurance and cost savings in nuclear project development. Benchmarks may involve one or many materials and thicknesses, types of sources, and measurement techniques. In this paper the benchmark experiments of varying complexity are chosen to study the transport properties of some popular materials and thicknesses. These were analyzed using three-dimensional (3-D) models and continuous energy libraries of MCNP4B2, a Monte Carlo code developed at Los Alamos National Laboratory, New Mexico. A shielding benchmark library provided the experimental data and allowed a wide range of choices for source, geometry, and measurement data. The experimental data had often been used in previous analyses by reputable groups such as the Cross Section Evaluation Working Group (CSEWG) and the Organization for Economic Cooperation and Development/Nuclear Energy Agency Nuclear Science Committee (OECD/NEANSC).

Hunter, H.T.; Slater, C.O.; Holland, L.B.; Tracz, G.; Marshall, W.J.; Parsons, J.L.

2000-09-17

146

Storage-Intensive Supercomputing Benchmark Study  

SciTech Connect

Critical data science applications requiring frequent access to storage perform poorly on today's computing architectures. This project addresses efficient computation of data-intensive problems in national security and basic science by exploring, advancing, and applying a new form of computing called storage-intensive supercomputing (SISC). Our goal is to enable applications that simply cannot run on current systems, and, for a broad range of data-intensive problems, to deliver an order of magnitude improvement in price/performance over today's data-intensive architectures. This technical report documents much of the work done under LDRD 07-ERD-063 Storage Intensive Supercomputing during the period 05/07-09/07. The following chapters describe: (1) a new file I/O monitoring tool iotrace developed to capture the dynamic I/O profiles of Linux processes; (2) an out-of-core graph benchmark for level-set expansion of scale-free graphs; (3) an entity extraction benchmark consisting of a pipeline of eight components; and (4) an image resampling benchmark drawn from the SWarp program in the LSST data processing pipeline. The performance of the graph and entity extraction benchmarks was measured in three different scenarios: data sets residing on the NFS file server and accessed over the network; data sets stored on local disk; and data sets stored on the Fusion I/O parallel NAND Flash array. The image resampling benchmark compared performance of software-only to GPU-accelerated. In addition to the work reported here, an additional text processing application was developed that used an FPGA to accelerate n-gram profiling for language classification. The n-gram application will be presented at SC07 at the High Performance Reconfigurable Computing Technologies and Applications Workshop. The graph and entity extraction benchmarks were run on a Supermicro server housing the NAND Flash 40GB parallel disk array, the Fusion-io. The Fusion system specs are as follows: SuperMicro X7DBE Xeon Dual Socket Blackford Server Motherboard; 2 Intel Xeon Dual-Core 2.66 GHz processors; 1 GB DDR2 PC2-5300 RAM (2 x 512); 80GB Hard Drive (Seagate SATA II Barracuda). The Fusion board is presently capable of 4X in a PCIe slot. The image resampling benchmark was run on a dual Xeon workstation with NVIDIA graphics card (see Chapter 5 for full specification). An XtremeData Opteron+FPGA was used for the language classification application. We observed that these benchmarks are not uniformly I/O intensive. The only benchmark that showed greater that 50% of the time in I/O was the graph algorithm when it accessed data files over NFS. When local disk was used, the graph benchmark spent at most 40% of its time in I/O. The other benchmarks were CPU dominated. The image resampling benchmark and language classification showed order of magnitude speedup over software by using co-processor technology to offload the CPU-intensive kernels. Our experiments to date suggest that emerging hardware technologies offer significant benefit to boosting the performance of data-intensive algorithms. Using GPU and FPGA co-processors, we were able to improve performance by more than an order of magnitude on the benchmark algorithms, eliminating the processor bottleneck of CPU-bound tasks. Experiments with a prototype solid state nonvolative memory available today show 10X better throughput on random reads than disk, with a 2X speedup on a graph processing benchmark when compared to the use of local SATA disk.

Cohen, J; Dossa, D; Gokhale, M; Hysom, D; May, J; Pearce, R; Yoo, A

2007-10-30

147

Emergency department performance measures and benchmarking summit.  

PubMed

The findings are presented of a consensus group created to address the standardization of performance measures for emergency medicine. This group, whose members have affiliations with most major organizations interested in emergency medicine performance, benchmarking and quality improvement, was tasked with standardizing definitions pertinent to emergency department performance measures, creating a set of general and operational measures, developing a comparison system for benchmarking and creating a plan for the dissemination of this information. The formation of this group, the problem statement, and the mission statement for the summit are all described, and the consensus document is presented. PMID:16946283

Welch, Shari; Augustine, James; Camargo, Carlos A; Reese, Charles

2006-08-31

148

Benchmark Calculations for Higher-Order Parabolic Equations.  

National Technical Information Service (NTIS)

Benchmark solutions generated with parabolic equation (PE) models are presented for range-dependent underwater acoustic propagation problems involving both penetrable and perfectly reflection ocean bottoms. The solution of the wide-angle PE of Claerbout (...

M. D. Collins

1990-01-01

149

Noise control of waste water pipes  

NASA Astrophysics Data System (ADS)

Noise radiated by waste water pipes is a major concern in multifamily housing projects. While the most common solution to this problem is to use cast-iron pipes in lieu of plastic pipes, this may not be sufficient in high-end applications. It should also be noted that many (if not most) multifamily housing projects in the U.S.A. are constructed with plastic waste piping. This paper discusses some of the measures that developers are currently using to control noise from both plastic and cast-iron waste pipes. In addition, results of limited noise measurements of transient water flow in plastic and cast-iron waste pipes will be presented.

Lilly, Jerry

2005-09-01

150

Human Benchmarking of Expert Systems.  

National Technical Information Service (NTIS)

This document outlines the strategy used for benchmarking expert systems to human performance. Two major alternatives for human benchmarking of expert system are proposed: computer science driven or psychological process driven. The computer science drive...

A. Jacoby H. F. O'Neil K. M. Swigger Y. Ni

1990-01-01

151

Benchmark Portability System - User's Guide.  

National Technical Information Service (NTIS)

The Benchmark Portability System (BPS) is designed to facilitate the process of benchmark conversion, evaluation and implementation. The BPS process, sometimes referred to as sanitation, takes user source COBOL programs from the native machine, and create...

1974-01-01

152

Applications of heat pipes to cool PWBS and hybrid microcircuits  

NASA Astrophysics Data System (ADS)

Some of the advanced thermal management techniques used to reduce operating junction temperature under extreme environmental temperature conditions are discussed. Heat pipes in actual electronic packaging applications, and those under development, are discussed. Performance characteristics of heat pipes are given, and examples are described of how thermal problems in electronic packaging are solved through the use of heat pipes.

Sekhon, K. S.

153

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

154

Cast Bronze Benchmark  

USGS Multimedia Gallery

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

2009-07-22

155

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

156

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…

Bers, Trudy

2012-01-01

157

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

158

Comparison of five benchmarks  

SciTech Connect

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

Huss, J. E.; Pennline, J. A.

1987-02-01

159

PNNL Information Technology Benchmarking  

Microsoft Academic Search

Benchmarking is a methodology for searching out industry best practices that lead to superior performance. It is exchanging information, not just with any organization, but with organizations known to be the best within PNNL, in industry, or in dissimilar industries with equivalent functions. It is used as a continuous improvement tool for business and technical processes, products, and services. Information

DD Hostetler

1999-01-01

160

Benchmarking: graphics workstations  

SciTech Connect

This paper reports on work being performed to benchmark a new breed of machines, the graphics workstations for scientific and engineering applications. We begin with the history of workstations and how they developed. Many different forces created the graphics workstation. Scientific and engineering calculations are traditionally performed by super computers in a computing center. The graphic workstation was introduced, and this technology was added to the computing environment. The answers we need are ... what can the workstations do and when do we remove the programs or parts of programs from supercomputers and place them on worstations. Benchmarks and what they can and cannot measure are discussed in this light. The particulars about graphics benchmarks and the operating system, including windows, are reviewed, then the benchmarks we are using are described and the results are presented. Since this work is never finished, future plans are also discussed. The emphasis of our work is toward scientific and engineering workstations connected with existing mainframe computers. In the industry today we hear the term JAWS (Just Another WorkStation) when a new workstation is introduced. What does the new product do beyond those on the market. In this paper we present ways to measure and tell the difference between workstations.

Brown, B.E.; Judd, R.L.

1985-09-11

161

Core Benchmarks Descriptions.  

National Technical Information Service (NTIS)

The document issued according to Work Release KI-WR04RTP. P. 00-12-A describes the list of benchmarks and functionals necessary for verification of computer package of Russian Research Center Kurchatov Institute. BIPR-7A, PERMAK-A and others. The first st...

A. M. Pavlovichev

2001-01-01

162

Benchmarking and improving construction productivity  

Microsoft Academic Search

States that the benefits of benchmarking are still largely unrecognized in the construction industry, despite the fact that the best practice concept has been indirectly investigated by both practitioners and researchers. Notes that some confusion seems to exist in construction circles as to what exactly benchmarking is and what it can achieve to improve productivity. Addresses the benchmarking concept and

Sherif Mohamed

1996-01-01

163

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

164

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

165

Pipe protection bibliography  

Microsoft Academic Search

Pipes and pipelines are being used for an ever widening range of materials, for increasing flows and in harsher applications. There is also more legal and social pressure to reduce the hazards associated with handling materials in pipes. All of this increases the demand for improved pipe reliability. Two of the major preventable causes of pipe failure are corrosion and

1987-01-01

166

Accelerated Corrosion of Copper-Nickel Piping.  

National Technical Information Service (NTIS)

Unexpectedly severe corrosion occurred in cupro-nickel piping in seawater cooling systems aboard ships built in one location. A workshop, convened to discuss the problem, identified turbulence as a major contributing factor, and the practice of running th...

1977-01-01

167

A BENCHMARK PROBLEM FOR STRUCTURAL HEALTH MONITORING  

Microsoft Academic Search

The importance of developing robust monitoring systems that can detect and locate progressive deterioration in structures or abrupt damage induced by extreme load- ing events is well recognized in the aero- space, mechanical, and civil engineering communities. In the case of civil structures, such as buildings, bridges, off-shore plat- forms or dams, the most commonly utilized approach for SHM (structural

James Beck; Dionisio Bernal

2001-01-01

168

Dynamic simulation recalls condensate piping event  

SciTech Connect

This article describes how experience gained from simulating and reconstructing a condensate piping event will be used by Consolidated Edison to analyze control system problems. A cooperative effort by Con Edison and the Chemical Engineering Department at Polytechnic University used modular modeling system to investigate the probable cause of a Con Edison condensate piping event. Con Edison commissioned the work to serve as a case study for the more general problem of control systems analysis using dynamic simulation and MMS.

Farrell, R.J.; Reneberg, K.O. (Polytechnic Univ., Brooklyn, NY (United States)); Moy, H.C. (Consolidated Edison Co., New York, NY (United States))

1994-05-01

169

Pipe crawlers: Versatile adaptations for real applications  

SciTech Connect

A problem at the Savannah River Site requires the unique application of a pipe crawler. A number of stainless steel pipes buried in concrete require ultrasonic inspection of the heat affected zones of the welds for detection of flaws or cracks. The paper describes the utilization of an inch-worm motion pipe crawler which negotiates a 90 degree reducing elbow with significant changes in diameter and vertical sections before entering the area of concern. After a discussion of general considerations and problem description, special requirements to meet the objectives and the design approach regarding the tractor, control system, instrument carriage, and radiation protection are discussed. 2 refs., 11 figs. (MB)

Hapstack, M.; Talarek, T.R.

1990-01-01

170

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

171

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

172

Advances in Cured-in-Place Pipe Rehabilitation for Pressurized Piping Systems  

Microsoft Academic Search

The prevention of internal corrosion, erosion, pitting, biofouling, MIC and general degradation is vital to the reliable performance of pressurized piping systems. The availability of these systems is critical to the efficient and safe operation of facilities in the process industries. Historically, there have been various alternatives available as solutions to these problems, including water treatment, coatings and piping replacement.

Keith B. Oxner; Todd Allsup

173

Mixing in Helical Pipes  

NASA Astrophysics Data System (ADS)

We consider advection and diffusion of a passive scalar in a helical pipe. By assuming that the curvature and torsion are small (equivalent to small Dean number) and the Reynolds number is moderate, we can use a closed form approximation, due to Dean (1927) and Germano (1982), for the induced recirculation. We investigate the problem numerically using a split-step particle method for a variety of localized initial conditions. The problem is governed by two parameters: a nondimensional diffusion constant D (typically small), and the scaled ratio of torsion to curvature ?. At small times, the longitudinal width of the particle distribution, ?, is governed by diffusive effects (? ? ?Dt). At large times, Taylor diffusion dominates (? ? ?t/D). However, at intermediate times, a ballistic region exists where the width spreads linearly, as postulated by Mezic & Wiggins (1994). We also discuss how these various behaviors scale with the parameters D and ?.

Gratton, Michael B.; Bernoff, Andrew J.

2001-11-01

174

Verification and benchmarking of ABAQUS and PATRAN for heat transfer applications  

SciTech Connect

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

Hawkes, G.L.

1989-08-01

175

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

176

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

177

INTERIOR VIEW WITH PIPE CASTING MACHINE CASTING A 24' PIPE ...  

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

INTERIOR VIEW WITH PIPE CASTING MACHINE CASTING A 24' PIPE AND OPERATOR JOHNNY NIXON. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

178

INTERIOR VIEW WITH PIPE CASTING MACHINE EXTRUDING A 24' PIPE ...  

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

INTERIOR VIEW WITH PIPE CASTING MACHINE EXTRUDING A 24' PIPE AND OPERATOR JOHNNY NIXON. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

179

Reusable pipe flange covers  

DOEpatents

A molded, flexible pipe flange cover for temporarily covering a pipe flange and a pipe opening includes a substantially round center portion having a peripheral skirt portion depending from the center portion, the center portion adapted to engage a front side of the pipe flange and to seal the pipe opening. The peripheral skirt portion is formed to include a plurality of circumferentially spaced tabs, wherein free ends of the flexible tabs are formed with respective through passages adapted to receive a drawstring for pulling the tabs together on a back side of the pipe flange.

Holden, James Elliott (Simpsonville, SC); Perez, Julieta (Houston, TX)

2001-01-01

180

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

181

Study on Plastic Pipes.  

National Technical Information Service (NTIS)

District heating pipelines are usually placed by using medium pipes consisting of steel; it is only in some exceptional cases that plastics are used. In future, plastics could be used for district heating subdistribution in competition with steel pipes pr...

A. Tautz

1982-01-01

182

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

183

Core Benchmarks Descriptions  

SciTech Connect

Actual regulations while designing of new fuel cycles for nuclear power installations comprise a calculational justification to be performed by certified computer codes. It guarantees that obtained calculational results will be within the limits of declared uncertainties that are indicated in a certificate issued by Gosatomnadzor of Russian Federation (GAN) and concerning a corresponding computer code. A formal justification of declared uncertainties is the comparison of calculational results obtained by a commercial code with the results of experiments or of calculational tests that are calculated with an uncertainty defined by certified precision codes of MCU type or of other one. The actual level of international cooperation provides an enlarging of the bank of experimental and calculational benchmarks acceptable for a certification of commercial codes that are being used for a design of fuel loadings with MOX fuel. In particular, the work is practically finished on the forming of calculational benchmarks list for a certification of code TVS-M as applied to MOX fuel assembly calculations. The results on these activities are presented.

Pavlovichev, A.M.

2001-05-24

184

Pipe-to-pipe impact program  

SciTech Connect

This report documents the tests and analyses performed as part of the Pipe-to-Pipe Impact (PTPI) Program at the Pacific Northwest Laboratory. This work was performed to assist the NRC in making licensing decisions regarding pipe-to-pipe impact events following postulated breaks in high energy fluid system piping. The report scope encompasses work conducted from the program's start through the completion of the initial hot oil tests. The test equipment, procedures, and results are described, as are analytic studies of failure potential and data correlation. Because the PTPI Program is only partially completed, the total significance of the current test results cannot yet be accurately assessed. Therefore, although trends in the data are discussed, final conclusions and recommendations will be possible only after the completion of the program, which is scheduled to end in FY 1984.

Alzheimer, J.M.; Bampton, M.C.C.; Friley, J.R.; Simonen, F.A.

1984-06-01

185

Abrasion resistant heat pipe  

Microsoft Academic Search

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

1984-01-01

186

Abrasion resistant heat pipe  

Microsoft Academic Search

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

Donald M

1984-01-01

187

Bonded flexible pipe  

Microsoft Academic Search

This paper presents an overview of bonded flexible pipe improvements primarily driven by environmental safety as applied to offshore development using mobile production systems. Bonded pipe is a flexible pipe where the steel reinforcement is integrated and bonded to a vulcanized elastomeric material. Textile material is included in the structure to obtain additional structural reinforcement or to separate elastomeric layers.

Val M. Northcutt

2000-01-01

188

Heat pipe system  

Microsoft Academic Search

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

H. L. Kroebig; F. J. Riha

1974-01-01

189

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

190

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

191

TsunaFLASH Benchmark and Its Verifications  

NASA Astrophysics Data System (ADS)

In the end of year 2008 TsunAWI (Tsunami unstructured mesh finite element model developed at Alfred Wegener Institute) by Behrens et al. (2006 - 2008) [Behrens, 2008], had been launched as an operational model in the German - Indonesian Tsunami EarlyWarning System (GITEWS) framework. This model has been benchmarked and verified with 2004 Sumatra-Andaman mega tsunami event [Harig et al., 2008]. A new development uses adaptive mesh refinement to improve computational efficiency and accuracy, this approach is called TsunaFLASH [Pranowo et al., 2008]. After the initial development and verification phase with stabilization efforts, and study of refinement criteria, the code is now mature enough to be validated with data. This presentation will demonstrate results of TsunaFLASH for the experiments with diverse mesh refinement criteria, and benchmarks; in particular the problem set-1 of IWLRM, and field data of the Sumatra-Andaman 2004 event.

Pranowo, Widodo; Behrens, Joern

2010-05-01

192

Welding bimetal pipes in duplex stainless steel  

Microsoft Academic Search

Butting bimetal pipes in duplex stainless steel are quite recent and present a set of interesting characteristics especially\\u000a for oil and gas transportation, namely weight to corrosion resistance ratio. Gas tungsten arc (GTA) welding is used to join\\u000a these pipes, but several problems are identified as lack of penetration and cracking resulting not only from the material\\u000a itself, but also

A. M. Torbati; R. M. Miranda; L. Quintino; S. Williams

2011-01-01

193

Interactive fluid-structural dynamic problems in power engineering, presented at the Joint Conference of the Pressure Vessels and Piping, Materials, Nuclear Engineering, Solar Energy Divisions, 1981  

SciTech Connect

Proceedings includes 11 papers, in which emphasis has been placed on understanding the physics of coupled fluid-structure systems commonly encountered in the power generation industry and on clarifying the different methods of solving the problem. Papers that solve specific problems are included mainly as illustrative examples. Topics considered include: nuclear reactors and power plants and their safeguard systems; liquid storage tanks; vapor quench systems; steam generators; and seismic wave effects. All papers are abstracted and indexed separately.

Au-Yang, M.K.; Moody, F.J. (eds.)

1981-01-01

194

Interactive fluid-structural dynamic problems in power engineering, presented at the joint conference of the pressure vessels and piping, materials, nuclear engineering, solar energy divisions, 1981  

SciTech Connect

Proceedings includes 11 papers, in which emphasis has been placed on understanding the physics of coupled fluid-structure systems commonly encountered in the power generation industry and on clarifying the different methods of solving the problem. Papers that solve specific problems are included mainly as illustrative examples. Topics considered include: nuclear reactors and power plants and their safeguard systems; liquid storage tanks; vapor quench systems; steam generators; and seismic wave effects. Seven papers are abstracted and indexed separately.

Au-Yang, M.K.; Moody, F.J. (eds.)

1981-01-01

195

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

196

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

197

Benchmark Factors in Student Retention.  

ERIC Educational Resources Information Center

The first purpose of this study was to identify significant factors affecting the first benchmark in retaining students in college--the decision to enroll in the first fall semester after orientation. The second purpose was to examine enrollment decisions at the second benchmark--the decision to re-enroll in the second fall semester after freshman…

Waggener, Anna T.; Smith, Constance K.

198

Benchmark Dose Modeling - Advanced Topics  

EPA Science Inventory

Benchmark Dose Modeling – Advanced Topics Course The objectives of this full-day course are to provide participants with training on how to use the U.S. Environmental Protection Agency’s (EPA) Benchmark Dose Modeling Software (BMDS) and related software programs to fa...

199

Controlled heat pipes  

NASA Astrophysics Data System (ADS)

A thermodynamic analysis of the operation of controlled heat pipes is presented. Topics covered include a classification of controlled heat pipes; attention is given to heat pipes in the dry saturated vapor regime, with a superheated vapor, with a supercooled liquid phase, with a superheated vapor and a supercooled liquid phase, and with moist vapor. Also covered are heat pipes with passive or active control, and the classification of controlled heat pipes according to the function (application) realized. Applications include heat diodes, temperature stabilizers, a heat bridge, a heat flow regulator, and a heat switch.

Vasilev, L. L.; Konev, S. V.; Tomchak, V.; Danelevich, Ia.

1983-07-01

200

Controlled heat pipes  

NASA Astrophysics Data System (ADS)

A thermodynamic analysis of the operation of controlled heat pipes is presented. Topics covered include a classification of controlled heat pipes; attention is given to heat pipes in the dry saturated vapor regime, with a superheated vapor, with a supercooled liquid phase, with a superheated vapor and a supercooled liquid phase, and with moist vapor. Also covered are heat pipes with passive or active control, and the classification of controlled heat pipes according to the function (application) realized. Applications include heat diodes, temperature stabilizers, a heat bridge, a heat flow regulator, and a heat switch.

Vasilev, L. L.; Konev, S. V.; Tomchak, V.; Danelevich, Ia.

1984-01-01

201

Pipe-to-pipe impact program  

SciTech Connect

The objective of this research was to determine the extent of damage that occurs when two pipes experience an impact event due to one whipping against the other. The research was conducted through experimental and analytical approaches. The former required the development of a specialized impact machine that could accelerate a whipping pipe with sufficient energy to cause failure of a target pipe that was heated and pressurized to Pressurized Water Reactor (PWR) conditions. Damage was measured in terms of crushing, bending, and failure. The results of the tests permitted the correlation between pipes of a certain size and the damage they could cause when impacting with a certain amount of known energy. These results were used to evaluate the pipe whip criteria in the Standard Review Plan 3.6.2-4. It was established that the criteria conditions did not fully represent the results obtained experimentally. An analysis procedure to model the pipe whip event was developed and used to establish the test matrix for the experimental program. This analytical procedure can also be used to predict deformation and rupture for postulated pipe whip scenarios. 17 refs.

Alzheimer, J.M.; Bampton, M.C.C.; Friley, J.R.; Simonen, F.A.

1987-05-01

202

Regional Competitive Intelligence: Benchmarking and Policymaking  

Microsoft Academic Search

Huggins R. Regional competitive intelligence: benchmarking and policy-making, Regional Studies. Benchmarking exercises have become increasingly popular within the sphere of regional policy-making. This paper analyses the concept of regional benchmarking and its links with regional policy-making processes. It develops a typology of regional benchmarking exercises and benchmarkers, and critically reviews the literature. It is argued that critics of regional benchmarking

Robert Huggins

2010-01-01

203

Benchmarking monthly homogenization algorithms  

NASA Astrophysics Data System (ADS)

The COST (European Cooperation in Science and Technology) Action ES0601: Advances in homogenization methods of climate series: an integrated approach (HOME) has executed a blind intercomparison and validation study for monthly homogenization algorithms. Time series of monthly temperature and precipitation were evaluated because of their importance for climate studies and because they represent two important types of statistics (additive and multiplicative). The algorithms were validated against a realistic benchmark dataset. The benchmark contains real inhomogeneous data as well as simulated data with inserted inhomogeneities. Random break-type inhomogeneities were added to the simulated datasets modeled as a Poisson process with normally distributed breakpoint sizes. To approximate real world conditions, breaks were introduced that occur simultaneously in multiple station series within a simulated network of station data. The simulated time series also contained outliers, missing data periods and local station trends. Further, a stochastic nonlinear global (network-wide) trend was added. Participants provided 25 separate homogenized contributions as part of the blind study as well as 22 additional solutions submitted after the details of the imposed inhomogeneities were revealed. These homogenized datasets were assessed by a number of performance metrics including (i) the centered root mean square error relative to the true homogeneous value at various averaging scales, (ii) the error in linear trend estimates and (iii) traditional contingency skill scores. The metrics were computed both using the individual station series as well as the network average regional series. The performance of the contributions depends significantly on the error metric considered. Contingency scores by themselves are not very informative. Although relative homogenization algorithms typically improve the homogeneity of temperature data, only the best ones improve precipitation data. Training was found to be very important. Moreover, state-of-the-art relative homogenization algorithms developed to work with an inhomogeneous reference are shown to perform best. The study showed that currently automatic algorithms can perform as well as manual ones.

Venema, V. K. C.; Mestre, O.; Aguilar, E.; Auer, I.; Guijarro, J. A.; Domonkos, P.; Vertacnik, G.; Szentimrey, T.; Stepanek, P.; Zahradnicek, P.; Viarre, J.; Müller-Westermeier, G.; Lakatos, M.; Williams, C. N.; Menne, M.; Lindau, R.; Rasol, D.; Rustemeier, E.; Kolokythas, K.; Marinova, T.; Andresen, L.; Acquaotta, F.; Fratianni, S.; Cheval, S.; Klancar, M.; Brunetti, M.; Gruber, C.; Prohom Duran, M.; Likso, T.; Esteban, P.; Brandsma, T.

2011-08-01

204

KENTUCKY STRAIGHT PIPES REPORT, DECEMBER 2002  

EPA Science Inventory

The poor sanitary conditions and water pollution problems EPA observed in the Kentucky counties of Harlan, Martin, Bath, and Montgomery were of the highest concern. The widespread scale of both the straight pipe issues as well as package plant wastewater problems present an envir...

205

Twodant solutions for the 2-D C5G7 MOX benchmark  

Microsoft Academic Search

The C5G7 MOX benchmark was proposed to test the ability of commercial transport codes to treat reactor core problems without spatial homogenization. The benchmark requires solutions in the form of normalized pin powers as well as the eigenvalue. In the work, the two-dimensional benchmark calculation using the TWODANT code within the DANTSYS code package has been performed with proper spatial

Hong-chul Kim; Chi Young Han; Jong Kyung Kim

2004-01-01

206

ADEPT. Aerosol Deposition in Cylindrical Pipes  

SciTech Connect

ADEPT calculates the deposition of aerosols in straight cylindrical pipes during turbulent air flow. Aerosol deposition is calculated in a time-dependent manner based on empirical correlations for turbulent flow in pipes. The calculated deposition during a single time interval is cumulative with that of previous time intervals and results in a decreasing inner diameter of the pipe. The calculated deposition is assumed uniform over the length of the pipe. The entering aerosol distribution is specified by the user in the form of a log-normal distribution of accumulated mass versus particle size and may be time dependent. Entering flow conditions are also specified by the user and may also be time dependent. For simplicity and generality, the geometry implicit in the program is that of a cylindrical pipe with no bends or fittings. The flow is turbulent and monodirectional; only one set of inlet conditions may be applied at a given time. The flow parameters are not calculated along the length of pipe; therefore, the dynamic behavior of the aerosol within the pipe as well as the effects of reentrainment cannot be determined explicitly. A typical problem requires 2 minutes of CPU time.

Fazekas, P.; Tewarson, S.C [Burns and Roe, Oradell, NJ (United States)

1985-01-01

207

ADEPT. aerosol deposition in cylindrical pipes  

SciTech Connect

ADEPT calculates the deposition of aerosols in straight cylindrical pipes during turbulent air flow. Aerosol deposition is calculated in a time-dependent manner based on empirical correlations for turbulent flow in pipes. The calculated deposition during a single time interval is cumulative with that of previous time intervals and results in a decreasing inner diameter of the pipe. The calculated deposition is assumed uniform over the length of the pipe. The entering aerosol distribution is specified by the user in the form of a log-normal distribution of accumulated mass versus particle size and may be time dependent. Entering flow conditions are also specified by the user and may also be time dependent. For simplicity and generality, the geometry implicit in the program is that of a cylindrical pipe with no bends or fittings. The flow is turbulent and monodirectional; only one set of inlet conditions may be applied at a given time. The flow parameters are not calculated along the length of pipe; therefore, the dynamic behavior of the aerosol within the pipe as well as the effects of reentrainment cannot be determined explicitly. A typical problem requires 2 minutes of CPU time.

Fazekas, P.; Tewarson, S.C (Burns and Roe, Oradell, NJ (United States))

1985-01-01

208

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

209

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

210

Phase-covariant quantum benchmarks  

SciTech Connect

We give a quantum benchmark for teleportation and quantum storage experiments suited for pure and mixed test states. The benchmark is based on the average fidelity over a family of phase-covariant states and certifies that an experiment cannot be emulated by a classical setup, i.e., by a measure-and-prepare scheme. We give an analytical solution for qubits, which shows important differences with standard state estimation approach, and compute the value of the benchmark for coherent and squeezed states, both pure and mixed.

Calsamiglia, J.; Aspachs, M.; Munoz-Tapia, R.; Bagan, E. [Grup de Fisica Teorica, Universitat Autonoma de Barcelona, Bellaterra, 08193 Barcelona (Spain)

2009-05-15

211

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

212

A pipe stress program for the microcomputer  

SciTech Connect

Explains how a FOCAL program can be used to solve difficult multianchor pipe stress problems. Presents a 6-anchor problem that will run in a half-hour on a small micro. Gives a general discussion of the problem with a little history behind some of the formulas. Other parts of the series will offer the FOCAL program; a typical 6-anchor example showing how to enter data and how to run the program; and a very simple single plane, 3-anchor example. The calculation method involves dividing a piping system into branches and trunk pieces. Each branch is broken up into members consisting of a piece of straight pipe and half of the elbow which is simulated by a short tangent, as shown in a diagram. A flexibility matrix is calculated for every member, and these 6 X 7 matrices are all knitted together to produce one 6 X 7 matrix. Tables give knitting logic and unraveling logic.

Bridge, T.E.

1983-02-01

213

Pipe crawler with stabilizing midsection  

Microsoft Academic Search

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

W. T. Zollinger; R. C. Treanor

1994-01-01

214

Pipe crawler with stabilizing midsection  

Microsoft Academic Search

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

W. T. Zollinger; R. C. Treanor

2009-01-01

215

Pipe crawler with stabilizing midsection  

Microsoft Academic Search

A pipe crawler having a midsection that provides the stability and flexibty 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

William T. Zollinger; Richard C. Treanor

1994-01-01

216

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

217

Restaurant Energy Use Benchmarking Guideline.  

National Technical Information Service (NTIS)

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 ...

K. Field R. Hedrick V. Smith

2011-01-01

218

Benchmarking as an action research process  

Microsoft Academic Search

This study participates in the debate on advancing theoretical developments in the field of benchmarking processes. It suggests that approaching benchmarking as a research method helps to explicate the basis of benchmarking processes and at the same time offers tools for scientific research in this field. Adopting an interpretative, comparative concept analysis the study approaches benchmarking as an action research.

Paula Kyrö

2004-01-01

219

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

220

Riser pipe elevator  

SciTech Connect

This patent describes a method for storing and retrieving a riser pipe, comprising the steps of: providing an upright annular magazine comprised of an inside annular wall and an outside annular wall, the magazine having an open top; storing the riser pipe in a substantially vertically oriented position within the annular magazine; and moving the riser pipe upwardly through the open top of the annular magazine at an angle to the vertical along at least a portion of the length of the riser pipe.

Bennett, W.; Jimenez, A.F.

1987-09-08

221

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

SciTech Connect

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

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

2001-09-29

222

Risk decision making in operational safety management - experience from the Nordic benchmark study  

Microsoft Academic Search

Technical Research Centre of Finland (VTT) and Studsvik AB, Sweden, have simulated decision making of the Swedish Nuclear Power Inspectorate and a power company by applying decision models in a benchmark study. Based on the experience from the benchmark study, a decision analysis framework to be used in safety related problems is outlined. By this framework both the power companies

Jan Holmberg; Urho Pulkkinen; K. Poern; Kecheng Shen

1994-01-01

223

Implementation of Benchmarking Transportation Logistics Practices and Future Benchmarking Organizations  

SciTech Connect

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

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

2008-07-01

224

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

225

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

226

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

227

The effects of the noncondensable gas in the heat pipes  

Microsoft Academic Search

In the heat pipe, a heat transfer device with a highly effective thermal conductivity, the continuous evaporation and condensation of its working fluids are taking place. The performance of heat pipes depends considerably on the concentration of the noncondensable gas in the vapor. In this report, the solution of the problem of evaporation and condensation in the presence of noncondensable

T. Matsushita

1975-01-01

228

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

229

Avoid freeze-up of steam traps and their piping  

SciTech Connect

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

O'Keefe, W.

1993-12-01

230

Development of an in-pipe inspection vehicle  

Microsoft Academic Search

A traveling tether-cable powered in-pipe inspection unit has been developed that is ready for commercial use, as outlined below. This vehicle can be used to visually examine the interior of piping systems where problems could have occurred, but are not visible. The vehicle consists of one upper and two lower wheels of which the former can be rotated as well

Fujiwara; Shigeru

1995-01-01

231

Convective instability in pipe flow through a sudden expansion  

Microsoft Academic Search

Flow through a sudden expansion in a pipe has been the subject of a lot of recent scientific interest. The geometry occurs in many industrial processes, from heat exchangers to combustion chambers, and is closely related to the physiological problem of flow through a stenosis. The inlet flow from the upstream pipe is Poiseuille, which forms a central jet surrounded

James Seddon

2009-01-01

232

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

233

Insulated Pipe Clamp Design.  

National Technical Information Service (NTIS)

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 becau...

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

1980-01-01

234

Splayed mirror light pipes  

SciTech Connect

An expression is given for the transmission of the rectangular-section mirror light pipe. The expression is used to model throughputs for simulated solar conditions over a calender year. It is found that the splaying of a mirror light pipe results in a significant increase in throughputs particularly in winter months. (author)

Swift, P.D. [School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)

2010-02-15

235

These Pipes Are "Happening"  

ERIC Educational Resources Information Center

The author is blessed with having the water pipes for the school system in her office. In this article, the author describes how the breaking of the pipes had led to a very worthwhile art experience for her students. They practiced contour and shaded drawing techniques, reviewed patterns and color theory, and used their reasoning skills--all while…

Skophammer, Karen

2010-01-01

236

Heat transfer pipe  

Microsoft Academic Search

A heat transfer pipe for use in a heat exchanger such as air conditioner, freezer and boiler is disclosed wherein grooves are formed in the inner wall surface of the pipe, which are by far finer in size than the grooves that have been provided for the purpose of increasing the heat transfer area in general, and slanting relative to

K. Fujie; M. Itoh; T. Innami; H. Kimura; W. Nakayama; T. Yanagida

1977-01-01

237

Heat transfer in pipes  

Microsoft Academic Search

The heat transfer from hot water to a cold copper pipe in laminar and turbulent flow condition is determined. The mean flow through velocity in the pipe, relative test length and initial temperature in the vessel were varied extensively during tests. Measurements confirm Nusselt's theory for large test lengths in laminar range. A new equation is derived for heat transfer

T. Burbach

1985-01-01

238

Inspecting flexible pipe  

SciTech Connect

Construction characteristics of flexible pipe, including composite structure of alternating layers of material, polymer and gas permeation and structural prevention of explosive deformation (ED) are reviewed. The author contrasts bonded and nonbonded construction in order to relate flexible pipe's complex behavior to an inspection method.

Neffgen, J.M. (Pag-O-Flex A/S (NO))

1990-11-01

239

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

240

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

241

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

242

Extendable pipe crawler  

DOEpatents

A pipe crawler 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.

Hapstack, Mark (North Augusta, SC)

1991-01-01

243

Setting Up an Audio Database for Music Information Retrieval Benchmarking  

Microsoft Academic Search

In this white paper we summarize some general requirements and issues to be clarified in order to set up a usable database for audio-based MIR benchmarking. A broad-minded approach is required in order to go beyond pure retrieval issues and include other problems that underlie in the core or in the surroundings of Music Information Retrieval. We conclude with a

Perfecto Herrera-Boyer

2002-01-01

244

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

245

Direct numerical simulation of transition in the pipe flow with roughness  

Microsoft Academic Search

The paper investigates the development of transition in a cylindrical pipe flow with roughness. The problem is tackled here by direct numerical simulation with spectral and spectral element methods. The roughness is simulated by periodic suction\\/blowing (PSB) applied to the pipe wall for regular wall roughness. Randomly distributed wall roughness is achieved by putting random suction\\/blowing (RSB) on the pipe

Hua Shan; Zhaoshun Zhang; F. T. M. Nieuwstadt

1997-01-01

246

Randomized Benchmarking of Multiqubit Gates  

NASA Astrophysics Data System (ADS)

We describe an extension of single-qubit gate randomized benchmarking that measures the error of multiqubit gates in a quantum information processor. This platform-independent protocol evaluates the performance of Clifford unitaries, which form a basis of fault-tolerant quantum computing. We implemented the benchmarking protocol with trapped ions and found an error per random two-qubit Clifford unitary of 0.162±0.008, thus setting the first benchmark for such unitaries. By implementing a second set of sequences with an extra two-qubit phase gate inserted after each step, we extracted an error per phase gate of 0.069±0.017. We conducted these experiments with transported, sympathetically cooled ions in a multizone Paul trap—a system that can in principle be scaled to larger numbers of ions.

Gaebler, J. P.; Meier, A. M.; Tan, T. R.; Bowler, R.; Lin, Y.; Hanneke, D.; Jost, J. D.; Home, J. P.; Knill, E.; Leibfried, D.; Wineland, D. J.

2012-06-01

247

Benchmarking of finite element codes for radioactive material transportation packages  

SciTech Connect

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

Ammerman, D.J.

1996-10-01

248

Heat Pipe Design Through Generalized Extremal Optimization  

Microsoft Academic Search

In this paper, an application of the Generalized Extremal Optimization (GEO) algorithm to the optimization of a heat pipe (HP) for a space application is presented. The GEO algorithm is a generalization of the Extremal Optimization (EO) algorithm, devised to be applied readily to a broad class of design optimization problems regardless of the design space complexity it would face.

FABIANO LUIS DE SOUSA; VALERI V. VLASSOV; FERNANDO MANUEL RAMOS

2004-01-01

249

Stokes slip flow in a corrugated pipe  

Microsoft Academic Search

In vitro measurements in the context of blood flows, performed in micro fabricated microchannels are subject to the channel-walls exhibiting some degree of roughness. Interestingly it is realistic to note that microdomains such as arteries and capillaries are prone to constrictions for various pathological reasons. Such microdomained flow problems may be studied as flows through axially corrugated pipes using continuum

M. Vasudeviah; K. Balamurugan

1999-01-01

250

Improving cash flow through benchmarking.  

PubMed

Healthcare organizations can use two benchmarking techniques to improve their accounts receivable departments' performance: 1) studying the accounts receivable statistics of model healthcare organizations, and 2) visiting these model organizations in order to get a first-hand look at how they do business. Employing these two benchmarking techniques can help healthcare organizations reduce gross days revenue outstanding, bad debt, the length of time between the date a patient is discharged and the date a bill is mailed, the total percentage of receivables more than 90 days old, and general business office expenses related to collection. PMID:10146067

Nelson, B

1994-09-01

251

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

252

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

253

Pipe weld crown removal device  

Microsoft Academic Search

A device is provided for grinding down the crown of a pipe weld joining aligned pipe sections so that the weld is substantially flush with the pipe sections joined by the weld. The device includes a cage assembly comprising a pair of spaced cage rings adapted to be mounted for rotation on the respective pipe sections on opposite sides of

C. K. Sword; P. J. Sette

1992-01-01

254

Pipe weld crown removal device  

Microsoft Academic Search

This invention is comprised of a device that provides for grinding down the crown of a pipe weld joining aligned pipe sections so that the weld is substantially flush with the pipe sections joined by the weld. The device includes a cage assembly comprising a pair of spaced cage rings adapted to be mounted for rotation on the respective pipe

C. K. Sword; P. J. Sette

1991-01-01

255

Practical considerations in piping analysis  

Microsoft Academic Search

The conference proceedings contains 14 papers which consider innovative techniques to produce high quality work on time. Eight papers are abstracted separately. Topics covered include steamhammer in power plant piping, allowable pipe loads on rotating equipment nozzles, piping insulation, expansion joints, flanged connections, coal gasification combined cycle power plants, elimination of use of metallic expansion joints, piping engineering computer codes.

E. van Stijgeren; L. Krawzya; K. Steffens; J. Woodward

1982-01-01

256

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

257

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

258

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

259

Effective pipe coating takes care  

SciTech Connect

A discussion of the operations involved in the preparation of effective hot-enamel pipe coating covers the storage, drying, and cleaning of the pipe, including the segregation of pipe carried on the deck of ocean-going ships or barges so as to allow weathering to remove salt spray; application of primer coatings; melting and heating of enamel; application of the hot enamel coating; inspection; and storage of coated pipe, and concludes that the effectiveness of a hot-enamel pipe coating is a shared responsibility between the pipeline owner, pipe-coating materials manufacturer, and the pipe-coating contractor.

Polkinhorne, D.A.

1980-01-01

260

BEAM PIPE DESORPTION RATE IN RHIC.  

SciTech Connect

In the past, an increase of beam intensity in RHIC has caused several decades of pressure rises in the warm sections during operation. This has been a major factor limiting the RHIC luminosity. About 430 meters of NEG coated beam pipes have been installed in the warm sections to ameliorate this problem. Beam ion induced desorption is one possible cause of pressure rises. A series beam studies in RHIC has been dedicated to estimate the desorption rate of various beam pipes (regular and NEG coated) at various warm sections. Correctors were used to generate local beam losses and consequently local pressure rises. The experimental results are presented and analyzed in this paper.

HUANG, H.; FISCHER, W.; HE, P.; HSEUH, H.C.; IRISO, U.; PTITSYN, V.; TRBOJEVIC, D.; WEI, J.; YANG, S.Y.

2006-06-23

261

Miniature pipe crawler tractor  

SciTech Connect

A pipe crawler tractor may comprise a half tractor assembly having a first base drive wheel, a second base drive wheel, and a top drive wheel. The drive wheels are mounted in spaced-apart relation so that the top drive wheel is positioned between the first and second base drive wheels. The mounting arrangement is also such that the first and second base drive wheels contact the inside surface of the pipe at respective first and second positions and so that the top drive wheel contacts the inside surface of the pipe at a third position, the third position being substantially diametrically opposed to the first and second positions. A control system connected to the half tractor assembly controls the rotation of the first base wheel, the second base wheel, and the top drive wheel to move the half tractor assembly within the pipe.

McKay, Mark D. (Idaho Falls, ID); Anderson, Matthew O. (Idaho Falls, ID); Ferrante, Todd A. (Westerville, OH); Willis, W. David (Idaho Falls, ID)

2000-01-01

262

Miniature pipe crawler tractor  

SciTech Connect

A pipe crawler tractor may comprise a half tractor assembly having a first base drive wheel, a second base drive wheel, and a top drive wheel. The drive wheels are mounted in spaced-apart relation so that the top drive wheel is positioned between the first and second base drive wheels. The mounting arrangement is also such that the first and second base drive wheels contact the inside surface of the pipe at respective first and second positions and so that the top drive wheel contacts the inside surface of the pipe at a third position, the third position being substantially diametrically opposed to the first and second positions. A control system connected to the half tractor assembly controls the rotation of the first base wheel, the second base wheel, and the top drive wheel to move the half tractor assembly within the pipe.

McKay, M.D.; Anderson, M.O.; Ferrante, T.A.; Willis, W.D.

2000-03-14

263

Internal pipe attachment mechanism.  

National Technical Information Service (NTIS)

This invention is comprised of an attachment mechanism 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...

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

1993-01-01

264

Corrosion of Underground Pipe.  

National Technical Information Service (NTIS)

Corrosion of underground steel pipe was explored through a literature survey and experimental investigation. The changes in solution parameters which occur during cathodic protection and their effect on corrosion were examined. The variation in pH was clo...

K. Kelley N. G. Thompson

1983-01-01

265

Pipe Heat Transfer Calculation.  

National Technical Information Service (NTIS)

This is a group of computer programs to determine heat transfer of multiple pipe systems as well as to evaluate economics of underground heat distribution systems. ...Software Description: The system is written in the FORTRAN V programming language for im...

1973-01-01

266

The pipes of pan.  

PubMed

The pipes of pan is the crowning achievement of Pablo Picasso's neoclassical period of the 1920s. This monumental canvas depicts a mythological Mediterranean scene in which two sculpted classical giants stare out, seemingly across the centuries, toward a distant and lost Arcadia. Picasso was influenced by Greco-Roman art during his travels in Italy, and his neoclassical works typically portray massive, immobile, and pensive figures. Pan and his pipes are taken directly from Greek mythological lore by Picasso and placed directly into 20th century art. He frequently turned to various mythological figures throughout his metamorphosing periods. The Pipes of Pan was also influenced by the painter's infatuation with the beautiful American expatriate Sara Murphy, and the finished masterpiece represents a revision of a previously conceived neoclassical work. The Pipes of Pan now hangs in the Musee Picasso in Paris. PMID:15574231

Chalif, David J

2004-12-01

267

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

268

Benchmarking: A tool to enhance performance.  

National Technical Information Service (NTIS)

The Office of Environmental Management is bringing Headquarters and the Field together to implement process improvements throughout the Complex through a systematic process of organizational learning called benchmarking. Simply stated, benchmarking is a p...

J. F. Munro J. Kristal G. Thompson T. Johnson

1996-01-01

269

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

270

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

271

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

272

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

273

Alpha characterization inside pipes using ion-transport technology  

NASA Astrophysics Data System (ADS)

Many DOE facilities have several miles of waste pipe systems that are internally contaminated with various and often undetermined radio nuclides. Unfortunately, currently acceptable alpha detection technologies are inefficient, time consuming, and do not address the problems presented by small diameter or curved pipes. In general, the problem of detecting alpha contamination on the inside surface of pipes is complicated by the fact that alphas do not penetrate the pipe walls. Unlike their conventional counterparts, alpha detectors based on ion transport technology sense alpha particles by collecting the ions created in ambient air as the particle loses its kinetic energy. The ions inside the pipe are transported by a fan-generated air current to an electrode inside the detector, which is attached to one end of the pipe. The collected charge at the electrode is proportional to the number of ions created inside the pipe, which in turn is proportional to the number of alphas emitted. Typically, monitoring for alpha contamination inside pipes or ductwork involves disrupting the operation to access as much surface area as possible for standard alpha monitoring. The detector based on ion transport technology effectively minimizes such disruption and in many circumstances will allow for in situ monitoring of a system that might otherwise not be practically accessible to standard methods.

Rojas, S. P.; Rawool-Sullivan, M. W.; Williams, K. G.; Vaccarella, J. A.

274

Application of program generation technology in solving heat and flow problems  

NASA Astrophysics Data System (ADS)

Based on a new DIY concept for software development, an automatic program-generating technology attached on a software system called as Finite Element Program Generator (FEPG) provides a platform of developing programs, through which a scientific researcher can submit his special physico-mathematical problem to the system in a more direct and convenient way for solution. For solving flow and heat problems by using finite element method, the stabilization technologies and fraction-step methods are adopted to overcome the numerical difficulties caused mainly due to the dominated convection. A couple of benchmark problems are given in this paper as examples to illustrate the usage and the superiority of the automatic program generation technique, including the flow in a lid-driven cavity, the starting flow in a circular pipe, the natural convection in a square cavity, and the flow past a circular cylinder, etc. They are also shown as the verification of the algorithms.

Wan, Shui; Wu, Bangxian; Chen, Ningning

2007-05-01

275

Pipe flow of highly concentrated sludge.  

PubMed

Industries that pump sludges experience pressure to operate at higher concentrations with sludges that have high mechanical strength properties. The viscous character of the sludge becomes increasingly non-Newtonian and yield stress in nature. The two principal problems are regime determination and laminar flow settling, which ultimately results in pipe blockage. In facing the diversities that sludge management currently presents, it is important to resolve these issues and develop solutions for engineering practice. The approaches developed at the Flow Process Research Centre to deal with these problems are introduced. The objectives of this paper are to introduce experimental data of the phenomena associated with the pipe flow of highly concentrated sludge, and use these to develop and evaluate predictive modeling approaches suitable for engineering design purposes. For the prediction of transitional flow, a new general approach for visco-plastic fluids in industrially relevant pipe sizes is presented, based on dimensional analysis of the flow problem. Settled bed behavior is modeled using an adapted two-layer model approach, in all flow regimes. The modeling approaches are evaluated using the experimental results obtained. The analysis shows that the present work provides a workable solution for the prediction of the pipe flow of highly concentrated sludges, for engineering design purposes. PMID:18821237

Slatter, Paul

2008-11-01

276

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

277

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

278

Predi cting the Future with RASSP Benchmarks  

Microsoft Academic Search

Commercial computer programs for cost estimation are used to incrementally predict RASSP benchmark progress in many different areas, and serve as an aid in establishing a current-practice baseline for comparison. The programs are also used to predict costs beyond the scope of the benchmarks such as life cycle costs and costs for platforms not benchmarked. Some goals of the RASSP

James C. Anderson

279

Developing Internet E-Commerce Benchmarks  

Microsoft Academic Search

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

Dawn N. Jutla; Peter Bodorik; Yie Wang

1999-01-01

280

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

281

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

282

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

283

Characterization of pipes, drain lines, and ducts using the pipe explorer system  

SciTech Connect

As DOE dismantles its nuclear processing facilities, site managers must employ the best means of disposing or remediating hundreds of miles of potentially contaminated piping and duct work. Their interiors are difficult to access, and in many cases even the exteriors are inaccessible. Without adequate characterization, it must be assumed that the piping is contaminated, and the disposal cost of buried drain lines can be on the order of $1,200/ft and is often unnecessary as residual contamination levels often are below free release criteria. This paper describes the program to develop a solution to the problem of characterizing radioactive contamination in pipes. The technical approach and results of using the Pipe Explorer {trademark} system are presented. The heart of the system is SEA`s pressurized inverting membrane adapted to transport radiation detectors and other tools into pipes. It offers many benefits over other pipe inspection approaches. It has video and beta/gamma detection capabilities, and the need for alpha detection has been addressed through the development of the Alpha Explorer{trademark}. These systems have been used during various stages of decontamination and decommissioning of DOE sites, including the ANL CP-5 reactor D&D. Future improvements and extensions of their capabilities are discussed.

Cremer, C.D.; Kendrick, D.T.; Cramer, E.

1997-05-01

284

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

NASA Astrophysics Data System (ADS)

Corrugated pipes are widely used because they combine local rigidity with global flexibility. Whistling induced by flow through such pipes can lead to serious environmental and structural problems. The whistling of a multiple side branch system is compared to the whistling behavior of corrugated pipes. The study has been restricted to cavities with sharp edges which are convenient for theoretical modeling. The side branch depth is chosen to be equal to the side branch diameter, which corresponds to cavity geometries in typical corrugated pipes. The low frequency resonance modes of the multiple side branch system have been predicted by means of acoustic models, of which the validity has been tested experimentally. Several experiments have been carried out for characterizing the whistling behavior of the system. While the behavior of a multiple side branch system is interesting on its own it can be compared to that of corrugated pipes. These experiments show that the multiple side branch system is in many aspects a reasonable model for corrugated pipes. Advantage of the multiple side branch system is that it is an experimental setup allowing easy modification of cavity depth. We used this feature to identify the pressure nodes of the acoustic standing wave along the main pipe as the regions where sound is produced. This contradicts recent publications on corrugated pipes. Another interesting aspects is that the system appears to whistle at the second hydrodynamic mode of the cavities rather than at the first hydrodynamic mode. A prediction model for the whistling behavior is proposed, consisting of an energy balance, based on the vortex sound theory. The model predicts the observed Strouhal number but overestimates the acoustic fluctuation amplitude by a factor four.

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

2010-04-01

285

Pipe crack identification based on finite element method of second generation wavelets  

NASA Astrophysics Data System (ADS)

In this paper, a new method is presented to identify crack location and size, which is based on stress intensity factor suitable for pipe structure and finite element method of second generation wavelets (SGW-FEM). Pipe structure is dispersed into a series of nested thin-walled pipes. By making use of stress intensity factor of the thin-walled pipe, a new calculation method of crack equivalent stiffness is proposed to solve the stress intensity factor of the pipe structure. On this basis, finite element method of second generation wavelets is used to establish the dynamic model of cracked pipe. Then we combine forward problem with inverse problem in order to establish quantitative identification method of the crack based on frequency change, which provides a non-destructive testing technology with vibration for the pipe structure. The efficiency of the proposed method is verified by experiments.

Ye, Junjie; He, Yumin; Chen, Xuefeng; Zhai, Zhi; Wang, Youming; He, Zhengjia

2010-02-01

286

Remotely operated pipe connector  

DOEpatents

An apparatus for remotely assembling and disassembling a Graylock type coctor between a pipe and a closure for the pipe includes a base and a receptacle on the base for the closure. The pipe is moved into position vertically above the closure by a suitable positioning device such that the flange on the pipe is immediately adjacent and concentric with the flange on the closure. A moving device then moves two semicircular collars from a position free of the closure to a position such that the interior cam groove of each collar contacts the two flanges. Finally, a tensioning device automatically allows remote tightening and loosening of a nut and bolt assembly on each side of the collar to cause a seal ring located between the flanges to be compressed and to seal the closure. Release of the pipe and the connector is accomplished in the reverse order. Preferably, the nut and bolt assembly includes an elongate shaft portion on which a removable sleeve is located.

Josefiak, Leonard J. (Scotia, NY); Cramer, Charles E. (Guilderford, NY)

1988-01-01

287

Loop heat pipe radiator  

SciTech Connect

This paper describes the design and testing of a Loop Heat Pipe Radiator (LHPR) which was developed as an alternative to state-of-the-art axially-grooved heat pipes for space-based heat rejection which would be usable with tubing made of aluminum foil covered with a carbon-epoxy composite. The LHPR had an aluminum envelope and a polymer wick, and used ammonia as a working fluid. It was 4 meters long with a mass of 1.4 kg. The LHPR transported 500 watts at a 2.3 meter adverse inclination and 1500 watts when horizontal. This non-optimized LHPR had a 3000 watt-meter capability, which is four times greater than an axially-grooved heat pipe of similar power-handling capability and mass. In addition to a higher power handling capability, the LHPR has a much higher capillary margin than axially-grooved pipes. That high capillary margin simplifies ground testing in a 1-g environment by reducing the need for the careful levelling and vibration reduction required by axially-grooved pipes. {copyright} {ital 1996 American Institute of Physics.}

Sarraf, D.B.; Gernert, N.J. [Thermacore, Inc., 780 Eden Rd., Lancaster, Pennsylvania (United States)

1996-03-01

288

Geothermal Heat Pump Benchmarking Report  

SciTech Connect

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

None

1997-01-17

289

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

290

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

291

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

292

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

293

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

294

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

295

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

296

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

297

Heat pipes and use of heat pipes in furnace exhaust  

SciTech Connect

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)

2010-12-28

298

Preventing and Thawing Frozen Pipes  

MedlinePLUS

... Thunderstorm Tornado Tsunami Volcano Water Safety Wildfire Winter Storm Preventing and Thawing Frozen Pipes Protect Your Pets ... a Disaster or Emergency › Types of Emergency › Winter Storm › Preventing and Thawing Frozen Pipes Preventing and Thawing ...

299

Stresses in District Heating Pipes.  

National Technical Information Service (NTIS)

This report studies the possibilities to introduce new, higher, norms for the maximum stresses allowed in hot water pipes with a low number of complete temperature cycles. Suggestions for new criteria are presented for pipes of various design. (ERA citati...

S. Andersson S. Andersson D. Olofsson

1984-01-01

300

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,

301

Benchmark for poroelastic and thermoelastic numerical codes  

NASA Astrophysics Data System (ADS)

Using the method of complex potentials we present the closed form of analytical solution for the stresses and displacements around an elliptical cavity filled with fluid in the permeable poroelastic medium. The far-field pore pressure is different from the pressure inside cavity. The fluid is allowed to diffuse through the cavity's wall towards surrounding medium. The two-dimensional plane-strain and plane-stress models are considered with steady-state distribution of diffusive pore-fluid pressure. The diffusion of fluid is coupled to the deformation of a medium using a linear theory of poroelasticity. Since in the static case the diffusion of pore fluid is controlled by an ordinary Laplace equation, the problem is reduced to elastic problem with distribution of volume forces (known as seepage forces) along gradients of pore pressure. Due to similarity between poroelasticity and thermoelasticity, the present solution is applicable both to the poroelastic and thermoelastic problems with a steady-state distribution of pore pressure and temperature, respectively. Since it is getting more common to model the deformation coupled to Darcy-flow in geosciences and no clear criteria has been suggested for verification of numerical codes, we discuss the possible application of the analytical solution as the benchmark for testing of poroelastic and thermoelastic numerical codes. To stimulate a wider use of the solution for stresses, displacements and pore-fluid pressure around an elliptical cavity are implemented in MATLAB and can be downloaded from the web.

Rozhko, Alexander Y.

2008-12-01

302

Pipe Drafting with CAD. Teacher Edition.  

ERIC Educational Resources Information Center

This teacher's guide contains nine units of instruction for a course on computer-assisted pipe drafting. The course covers the following topics: introduction to pipe drafting with CAD (computer-assisted design); flow diagrams; pipe and pipe components; valves; piping plans and elevations; isometrics; equipment fabrication drawings; piping design…

Smithson, Buddy

303

Synthetic benchmark for modeling flow in 3D fractured media  

NASA Astrophysics Data System (ADS)

Intensity and localization of flows in fractured media have promoted the development of a large range of different modeling approaches including Discrete Fracture Networks, pipe networks and equivalent continuous media. While benchmarked usually within site studies, we propose an alternative numerical benchmark based on highly-resolved Discrete Fracture Networks (DFNs) and on a stochastic approach. Test cases are built on fractures of different lengths, orientations, aspect ratios and hydraulic apertures, issuing the broad ranges of topological structures and hydraulic properties classically observed. We present 18 DFN cases, with 10 random simulations by case. These 180 DFN structures are provided and fully documented. They display a representative variety of the configurations that challenge the numerical methods at the different stages of discretization, mesh generation and system solving. Using a previously assessed mixed hybrid finite element method (Erhel et al., 2009a), we systematically provide reference flow and head solutions. Because CPU and memory requirements stem mainly from system solving, we study direct and iterative sparse linear solvers. We show that the most cpu-time efficient method is a direct multifrontal method for small systems, while conjugate gradient preconditioned by algebraic multrigrid is more relevant at larger sizes. Available results can be used further as references for building up alternative numerical and physical models in both directions of improving accuracy and efficiency.

de Dreuzy, Jean-Raynald; Pichot, Géraldine; Poirriez, Baptiste; Erhel, Jocelyne

2013-01-01

304

Estimating Industry Benchmarks for the Value Added Tax  

Microsoft Academic Search

Various indicators (e.g., VAT-to-GNP ratio, VAT evasion rate) suggest that problems in VAT administration have not only persisted during the 1990s but also appear to have worsened. This study makes use of the 1994 Input Output Table to estimate industry benchmarks for the ratio of VAT-able inputs to total output as well as the effective VAT rate. In so doing,

Rosario G. Manasan

2002-01-01

305

Assessing 3-D Integrated Software Development Processes: A New Benchmark  

Microsoft Academic Search

\\u000a The increasing complexity and dynamic of software development have become the most critical challenges for large projects.\\u000a As one of the new emerged methodologies to these problems, TRISO-Model uses an integrated three-dimensional structure to classify\\u000a and organize the essential elements in software development. In order to simulate and evaluate the modeling ability of TRISO-Model,\\u000a a new benchmark is created in

Mingshu Li; Zhong Guan Cun

2006-01-01

306

Simulation of the Process of Water Freezing in a Round Pipe  

Microsoft Academic Search

The problem of freezing of pure water in a round pipe is treated with due regard for convection under asymmetric thermal boundary conditions in the absence of motion along the pipe. The problem is solved numerically using the control volume approach, SIMPLER algorithm, and the enthalpy method. Results are obtained for three Grashof (Gr) and six Biot (Bi) numbers: Gr

P. T. Zubkov; V. A. Kravchenko; E. M. Sviridov

2001-01-01

307

Adjustable-angle pipe fitting  

DOEpatents

This invention pertains to a pipe fitting for joining two pipes at a desired, preselected angle and comprises a curved section of pipe with a generally circular cross-section. One end of the curved pipe is preferably furnished with a bell fitting. The other end is adapted to be inserted into the bell of another pipe fitting. The surface of the pipe is marked with circumferential lines spaced at several-degree intervals, the lines corresponding to the angle of the bend which will result if the pipe is cut along that line. The outer diameter of the pipe is closely controlled to be the same throughout its length as the outer diameter of a straight pipe, so the cut end can be inserted into the bell of another fitting without further treatment, and the radius of curvature of the pipe is larger than a standard street elbow, preferably three to ten times the diameter of the pipe. Thus, a cut approximately perpendicular to the axial centerline can be made at any point along the length of the pipe to form an elbow of any desired angle.

Kronberg, J.W.

1991-01-01

308

Adjustable-angle pipe fitting  

DOEpatents

This invention pertains to a pipe fitting for joining two pipes at a desired, preselected angle and comprises a curved section of pipe with a generally circular cross-section. One end of the curved pipe is preferably furnished with a bell fitting. The other end is adapted to be inserted into the bell of another pipe fitting. The surface of the pipe is marked with circumferential lines spaced at several-degree intervals, the lines corresponding to the angle of the bend which will result if the pipe is cut along that line. The outer diameter of the pipe is closely controlled to be the same throughout its length as the outer diameter of a straight pipe, so the cut end can be inserted into the bell of another fitting without further treatment, and the radius of curvature of the pipe is larger than a standard street elbow, preferably three to ten times the diameter of the pipe. Thus, a cut approximately perpendicular to the axial centerline can be made at any point along the length of the pipe to form an elbow of any desired angle.

Kronberg, J.W.

1991-12-31

309

Corrugated pipe adhesive applicator apparatus  

Microsoft Academic Search

Apparatus for coating selected portions of the troughs of a corrugated pipe within an adhesive includes a support disposed within the pipe with a reservoir containing the adhesive disposed on the support. A pump, including a spout, is utilized for supplying the adhesive from the reservoir to a trough of the pipe. A rotatable applicator is supported on the support

Shirey; Ray A

1983-01-01

310

Corrugated pipe adhesive applicator apparatus  

Microsoft Academic Search

Apparatus for coating selected portions of the troughs of a corrugated pipe with an adhesive includes a support disposed within the pipe with a reservoir containing the adhesive disposed on the support. A pump, including a spout, is utilized for supplying the adhesive from the reservoir to a trough of the pipe. A rotatable applicator is supported on the support

Shirey

1983-01-01

311

Rarefied gas flow through a long circular pipe into vacuum  

NASA Astrophysics Data System (ADS)

Rarefied gas flow through a circular pipe into vacuum is studied on the basis of the direct numerical solution of the kinetic equation. The main emphasis of the study is on the end effects. The problem is solved in the completed geometrical setup with the pipe and reservoirs as well as incomplete setup in which the reservoirs are replaced by emission/no emission boundary conditions. The results for the flow rate and density distribution along the pipe are compared with the approximate solution based on the use of the locally one-dimensional assumption.

Titarev, V. A.; Shakhov, E. M.

2012-11-01

312

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

313

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

314

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

2011-07-13

315

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

2013-04-22

316

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

317

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

318

Benchmarking: A tool to enhance performance  

SciTech Connect

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

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

1996-12-31

319

Instability in pipe flow  

PubMed Central

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

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

2008-01-01

320

Instability in pipe flow.  

PubMed

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

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

2008-01-04

321

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

322

Plastic pipe testing techniques  

Microsoft Academic Search

As gas-distribution companies increasingly install polyethylene plastic piping, both the users and the producers of polyethylene will need to develop methods to predict the plastic's service-life expectancy and to determine the causes of any system failures that may occur. One particularly promising method is multipoint testing combined with improved failure-analysis techniques. Variants of this method include ASTM Method D2837, the

De Blieu

2009-01-01

323

Benchmarking of collision operators with momentum source corrections  

SciTech Connect

Several linearized collision operator models with parallel momentum conservation enforced by source functions are benchmarked against the correct collision operator based on Rosenbluth potentials. The model operators without energy diffusion allow for an analytic solution of a generalized Spitzer problem. For the other operators under investigation, an integrodifferential equation is solved. The benchmarking is performed both for the parallel conductivity with the ions assumed at rest and for the bootstrap current, where ion and electron flows are collisionally coupled. The accuracy of the results obtained with the operators varies from rather poor in the case of the simplest monoenergetic model to quite satisfactory for the models employing an energy-weighted parallel momentum source function.

Maassberg, H.; Beidler, C. D. [EURATOM Association, Max-Planck-Institut fuer Plasmaphysik, D-17491 Greifswald (Germany)

2010-05-15

324

Benchmarking Helps Measure Union Programs, Operations.  

ERIC Educational Resources Information Center

Explores three examples of benchmarking by college student unions. Focuses on how a union can collect information from other unions for use as benchmarking standards for the purposes of selling a concept or justifying program increases, or for comparing a union's financial performance to other unions. (EV)

Mann, Jerry

2001-01-01

325

Information quality benchmarks: product and service performance  

Microsoft Academic Search

Information quality (IQ) is an inexact science in terms of assessment and benchmarks. Although various aspects of quality and information have been investigated [1, 4, 6, 7, 9, 12], there is still a critical need for a methodology that assesses how well organizations develop information products and deliver information services to consumers. Benchmarks developed from such a methodology can help

Beverly K. Kahn; Diane M. Strong; Richard Y. Wang

2002-01-01

326

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

327

Los Alamos National Laboratory computer benchmarking 1988  

Microsoft Academic Search

This report summarizes the results of computer performance evaluations as measured by the Computer Research and Applications Group of the Los Alamos National Laboratory. The benchmarks were conducted between December 1986 and July 1988. Important characteristics of the machines tested are given, and execution times or megaflop rates for a set of portable Fortran 77 benchmark codes are listed. A

H. J. Wasserman

1988-01-01

328

A Benchmark Diagnostic Model Generation System  

Microsoft Academic Search

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

Jun Wang; Gregory M. Provan

2010-01-01

329

Sequenced Benchmarks for Geography and History  

ERIC Educational Resources Information Center

This report is one in a series of reference documents designed to assist those who are directly involved in the revision and improvement of content standards, as well as teachers who use standards and benchmarks to guide everyday instruction. Reports in the series provide information about how benchmarks might best appear in a sequence of…

Kendall, John S.; Richardson, Amy T.; Ryan, Susan E.

2005-01-01

330

Benchmarking and performance measurement: a statistical analysis  

Microsoft Academic Search

Purpose – The purpose of this paper is to explore the theoretical understanding and practical application of lead benchmarking and performance measurement as a way to achieve organisational change. Design\\/methodology\\/approach – The paper combines a theory building\\/theory testing approach. Based on literary findings a conceptual model has been postulated to identify constructs associated with upstream performance measurement and lead benchmarking.

Sandra Moffett; Karen Anderson-Gillespie; Rodney McAdam

2008-01-01

331

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

332

Linear Road: A Stream Data Management Benchmark  

Microsoft Academic Search

This paper specifies the Linear Road Benchmark for Stream Data Management Systems (SDMS). Stream Data Management Systems process streaming data by executing continuous and historical queries while producing query re - sults in real-time. This benchmark makes it possible to com- pare the performance characteristics of SDMS' relative to each other and to alternative (e.g., Relational Database) systems. Linear Road

Arvind Arasu; Mitch Cherniack; Eduardo F. Galvez; David Maier; Anurag Maskey; Esther Ryvkina; Michael Stonebraker; Richard Tibbetts

2004-01-01

333

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

334

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

335

Achieving internal process benchmarking: guidance from BASF  

Microsoft Academic Search

Purpose – The purpose of the work discussed in this paper is to understand, analyse and benchmark the “Packing and Filling” processes within BASF. A benchmarking project is described in detail which aimed to cover sites in different countries that supplied many different variants of finished goods in order to establish best practice and then to generate some options for

Mario Binder; Ben Clegg; Wolfgang Egel-Hess

2006-01-01

336

Gas Cooled Fast Reactor Benchmark Critical Assembly.  

National Technical Information Service (NTIS)

The GCFR Phase I assembly is the initial Gas-Cooled Fast Reactor Benchmark assembly on the ZPR-9 reactor at Argonne National Laboratory. It represents the first full scale mockup of a GCFR ever assembled. It is a clean, simple geometry benchmark reference...

S. K. Bhattacharyya R. D. McKnight W. R. Robinson E. M. Bohn G. K. Rusch

1975-01-01

337

Gas cooled fast reactor benchmark critical assembly  

Microsoft Academic Search

The GCFR Phase I assembly is the initial Gas-Cooled Fast Reactor ; Benchmark assembly on the ZPR-9 reactor at Argonne National Laboratory. It ; represents the first full scale mockup of a GCFR ever assembled. It is a clean, ; simple geometry benchmark reference for the 300 MW(e) GCFR Demonstration Plant ; designed by General Atomic Company. A description and

S. K. Bhattacharyya; R. D. McKnight; W. R. Robinson; E. M. Bohn; G. K. Rusch; F. H. Martens; L. G. LeSage

1975-01-01

338

Organizational Benchmarking Using the ISBSG Data Repository  

Microsoft Academic Search

The International Software Benchmarking Standards Group maintains a repository of data from numerous organizations' completed software projects. The ISBSG Data Repository has many uses, including project benchmarking, best-practice networking, and summary analyses. The repository, open to the public, has provided research data on several topics, including function points structure, project duration, and cost estimation

Christopher J. Lokan; Terry Wright; Peter R. Hill; Michael Stringer

2001-01-01

339

Benchmark Dose Modeling - Advanced Topics Course  

EPA Science Inventory

Benchmark Dose Modeling – Advanced Topics Course The objectives of this full-day course are to provide participants with training on how to use the U.S. Environmental Protection Agency’s (EPA) Benchmark Dose Modeling Software (BMDS) and related software programs to fa...

340

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...

341

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

342

40 CFR 141.172 - Disinfection profiling and benchmarking.  

Code of Federal Regulations, 2010 CFR

...172 - Disinfection profiling and benchmarking.] 40 PROTECTION OF ENVIRONMENT...141.172 Disinfection profiling and benchmarking. (a) Determination of...conducted by the State. (c) Disinfection benchmarking. (1) Any system required to...

2009-07-01

343

40 CFR 141.172 - Disinfection profiling and benchmarking.  

Code of Federal Regulations, 2010 CFR

... false Disinfection profiling and benchmarking. 141.172 Section 141.172...172 Disinfection profiling and benchmarking. (a) Determination of systems...by the State. (c) Disinfection benchmarking. (1) Any system required...

2010-07-01

344

Analysis and improvement of die design for the processing of extruded plastic pipes  

Microsoft Academic Search

Basket dies, also known as screen pack dies, have been widely used in centre-fed extrusion of plastic pipes as an alternative to conventional spider-supported pipe dies. The aim of introducing basket dies was to eliminate the production problem of ‘weld-lines’ caused when using spider pipe dies. However, a phenomenon has been observed experimentally when processing LDPE and HDPE using basket

Y Huang; C. R Gentle; M Lacey; P Prentice

2000-01-01

345

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

346

Robust Tomography using Randomized Benchmarking  

NASA Astrophysics Data System (ADS)

Conventional randomized benchmarking (RB) can be used to estimate the fidelity of Clifford operations in a manner that is robust against preparation and measurement errors --- thus allowing for a more accurate and relevant characterization of the average error in Clifford gates compared to standard tomography protocols. Interleaved RB (IRB) extends this result to the extraction of error rates for individual Clifford gates. In this talk we will show how to combine multiple IRB experiments to extract all information about the unital part of any trace preserving quantum process. Consequently, one can compute the average fidelity to any unitary, not just the Clifford group, with tighter bounds than IRB. Moreover, the additional information can be used to design improvements in control.

Silva, Marcus; Kimmel, Shelby; Johnson, Blake; Ryan, Colm; Ohki, Thomas

2013-03-01

347

Experimenting with a ``Pipe'' Whistle  

NASA Astrophysics Data System (ADS)

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 allows students in a physics of music or introductory physics course to study an example of an ``edge tone'' device that produces discrete sound frequencies. From their textbooks, students likely know about standing waves produced by pipes or strings, as well as the resonant frequencies for open and closed pipes. To go a bit further, they can also learn how the frequency of the sound wave depends on the orifice-to-edge distance of the wind instrument.

Stafford, Olga

2012-04-01

348

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

349

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

350

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

351

Thermal and mechanical codes first benchmark exercise: Part 1, Thermal analysis; Yucca Mountain Project  

SciTech Connect

Thermal and mechanical models for intact and jointed rock mass behavior are being developed, verified, and validated at Sandia National Laboratories for the Yucca Mountain Project. Benchmarking is an essential part of this effort and is the primary tool used to demonstrate verification of engineering software used to solve thermomechanical problems. This report presents the results of the first phase of the first thermomechanical benchmark exercise. In the first phase of this exercise, three finite element codes for nonlinear heat conduction and one coupled thermoelastic boundary element code were used to solve the thermal portion of the benchmark problem. The codes used by the participants in this study were DOT, COYOTE, SPECTROM-41, and HEFF. The problem solved by each code was a two-dimensional idealization of a series of drifts whose dimensions approximate those of the underground layout in the conceptual design of a prospective repository for high-level radioactive waste at Yucca Mountain. 20 refs., 50 figs., 3 tabs.

Costin, L.S.; Bauer, S.J.

1990-06-01

352

Computation of circulating fluidized-bed riser flow for the Fluidization VIII benchmark test  

SciTech Connect

Conservation of mass and momentum equations for the solid and for the gas phases was used to compute the hydrodynamics of flow of fluidized catalytic cracking particles in a vertical pipe (riser) for the 1995 benchmark modeling contest. The computer code predicted a new phenomenon: an off-center maximum flux. The computed time-average radial fluxes and particle concentrations agree with PSRI experimental data. The computer code also predicted the observed core-annular flow regime. For the lowest gas velocity and highest solids flux, the code predicted low-frequency, snakelike density oscillations.

Sun, B.; Gidaspow, D. [Illinois Inst. of Tech., Chicago, IL (United States). Dept. of Chemical and Environmental Engineering

1999-03-01

353

Solving bearing overheating problems  

Microsoft Academic Search

Overheating is a major indicator, along with vibration and noise, of an underlying problem affecting a bearing or related components. Because normal operating temperatures vary widely from one application to another, no single temperature is a reliable sign of overheating in every situation. By observing an application when it is running smoothly, a technician can establish a benchmark temperature for

Jendzurski

1995-01-01

354

ATHENA heat pipe transient model  

NASA Astrophysics Data System (ADS)

The ATHENA (Chow 1985) is a general purpose thermal hydraulic transient simulation code that was developed for the Magnetic Fusion Safety Project. The ATHENA two fluid model for two phase flow was modified to include the fluid physics unique to the heat pipe. This approach has resulted in a relatively sophisticated heat pipe transient model for a modest development effort. The model was used to simulate heat pipes for space power reactors, both as separate components and in integral simulation of coupled systems. The modifications that were made to the two fluid model to enable heat pipe simulation are described.

Ransom, Victor H.; Chow, Hueiming

355

ICSBEP Benchmarks For Nuclear Data Applications  

NASA Astrophysics Data System (ADS)

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

Briggs, J. Blair

2005-05-01

356

Intermediate Temperature Fluids for Heat Pipes and Loop Heat Pipes  

Microsoft Academic Search

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

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

357

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

358

Simplified analysis of shrinkage in pipe to pipe butt welds  

Microsoft Academic Search

Generally some shrinkage is typical of butt welding of pipes. Shrinkage due to butt welding could be more pronounced and significant in thin wall stainless steel pipes because the thermal expansion coefficient is roughly one and half times that of carbon steel. An axisymmetric finite element evaluation of hoop shrinkage associated with circumferential butt welds in thin wall stainless steel

Chakrapani Basavaraju

2000-01-01

359

Singing corrugated pipes revisited  

NASA Astrophysics Data System (ADS)

A long corrugated tube open at both ends sings notes which depend on the flow velocity of air flowing through the tube. The notes it sings are natural harmonics of the tube. In 1974, Crawford suggested an explanation for this: A given note will sing when the flow velocity is such that the ``bump frequency'' equals the frequency of the note, provided also that the flow velocity is sufficiently high to induce turbulent flow. He suggested two theories to explain the singing in terms of turbulence. One assumed that the onset of turbulence agrees with the classic Reynolds number for smooth tubes (Rsmooth~=2000) in which the characteristic length of the object that has air flowing in is equal to the diameter. The second assumed the characteristic length of the object was equal to the distance between the corrugations. Crawford reported having good agreement between the classic diameter-induced turbulence theory and experiment for some pipes. However, for other tubes he observed singing at Reynolds numbers that were much smaller than the classical result of 2000. For these, he could not establish if he was observing corrugation-induced turbulence. (He stated he did not have sufficient pipes.) After looking at a variety of tube diameters and corrugation lengths, we also observed (as Crawford reported) that some of the data agreed with the classic diameter-induced turbulence, and some did not. Ironically, the hypothesis Crawford introduced (and rejected) as an alternative possibility seems to fit ALL of our data quite well. A new Reynolds number associated with the onset of turbulence for corrugated pipes is presented: Rcorr~=500.

Cadwell, Louis H.

1994-03-01

360

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

361

Fire Endurance of Glassfibre Reinforcement Plastic Pipes.  

National Technical Information Service (NTIS)

Pipe systems on board ships are normally manufactured in steel. The application of glassfiber reinforced plastic (GRP) pipe systems in ship building offers, compared to steel pipes, several advantages such as light weight and a good corrosion resistance. ...

1984-01-01

362

49 CFR 195.112 - New pipe.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false New pipe. 195.112 Section 195...Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT...Design Requirements § 195.112 New pipe. Any new pipe installed in a pipeline...

2011-10-01

363

Steam Bubble Collapse, Water Hammer and Piping Network Response. Volume I. Steam Bubble Collapse and Water Hammer in Piping Systems: Experiments and Analysis.  

National Technical Information Service (NTIS)

Water hammer incidents in conventional and nuclear steam systems are an important problem of broad general interest in piping network design and transient operation. Water hammer in PWR steam generator sparger feed lines has, for example, been a recurrent...

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

1980-01-01

364

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

365

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

366

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

367

Light Pipes for Illumination Purposes, A Preliminary Study (Lysledere til Belysningsformal, En Forundersogelse).  

National Technical Information Service (NTIS)

The purpose of this project was to outline the possibilities and problems involved in using daylight, and especially sunlight, for indoor illumination with the help of light pipes. The dimensions of such pipes are more like those of ventilation ducts than...

E. Frederiksen

1980-01-01

368

The effect of 25 years of oil field flow line service on epoxy fiberglass pipe  

Microsoft Academic Search

Glass fiber-reinforced epoxy and vinyl ester piping systems have been used for more than 35 years to control corrosion problems in oil fields and chemical and industrial plants. Many case histories have documented successful performances of fiberglass-reinforced thermosetting plastics in a wide range of corrosive services. This information is reinforced by laboratory test data from flat laminates and pipe exposed

Oswald

1988-01-01

369

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

Microsoft Academic Search

Integral heat-pipe sandwich panels, which synergistically combine the thermal efficiency of heat pipes and the structural efficiency of honeycomb sandwich construction, were conceived as a means of alleviating thermal stress problems in the Langley Scramjet Engine. Test panels which utilized two different wickable honeycomb cores, facesheets with screen mesh sintered to the internal surfaces, and a liquid metal working fluid

C. J. Camarda; A. Basiulis

1983-01-01

370

Design and performance prediction of a novel double heat pipes type adsorption chiller for fishing boats  

Microsoft Academic Search

A novel double heat pipe type adsorber, which uses compound adsorbent of CaCl2 and expanded graphite to improve the adsorption performance, is designed. The double heat pipes are integrated into the adsorbers in order to solve the problem of the corrosion between seawater and the steel adsorber in ammonia system and improve the heat transfer performance of the adsorber. There

K. Wang; J. Y. Wu; Z. Z. Xia; S. L. Li; R. Z. Wang

2008-01-01

371

Finite-element analysis of conjugate heat transfer in axisymmetric pipe flows  

Microsoft Academic Search

A Galerkin-type finite element approach was used to study the effect of two-dimensional wall conduction on laminar convective heat transfer inside pipe flows. This conjugate heat transfer problem was studied for cases in which the external surface of the pipe is subjected to constant wall heat flux and constant wall temperature conditions. The wall conduction effects were found to be

R. M. Fithen; N. K. Anand

1988-01-01

372

Segregated solution technique for simulating the transient operation of heat pipes  

Microsoft Academic Search

Simulating the transient operation of fully thawed heat pipes involves solving a highly nonlinear homogeneous two-phase flow problem, which necessitates the development of a stable and efficient numerical technique. In this work, various segregated numerical techniques are implemented, and their accuracy and computation time requirement are examined using experimental data of a water heat pipe. Best results are obtained using

J. M. Tournier; M. S. El-Genk

2009-01-01

373

SEGREGATED SOLUTION TECHNIQUE FOR SIMULATING THE TRANSIENT OPERATION OF HEAT PIPES  

Microsoft Academic Search

Simulating the transient operation of fully thawed heat pipes involves solving a highly nonlinear homogeneous two-phase flow problem, which necessitates the development of a stable and efficient numerical technique. In this work, various segregated numerical techniques are implemented, and their accuracy and computation time requirement are examined using experimental data of a water heat pipe. Best results are obtained using

J.-M. Tournier; M. S. El-Genk

1994-01-01

374

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

375

Calculations to Benchmark Probabilistic Fracture Mechanics Computer Codes  

SciTech Connect

This paper describes calculations to estimate component failure frequencies for components using the PRO-LOCA and PRAISE probabilistic fracture mechanics (PFM) computer codes. These calculations focused on the failure mechanism of intergranular stress corrosion cracking for operating conditions that were known to have failed field components. The objective was to benchmark the newly developed PRO-LOCA code against the older PRAISE code that had a much longer history of prior applications. Another objective was to determine the extent to which uncertainties and modeling assumptions may impact calculated probabilities. It was established that advanced modeling capabilities in the PRO-LOCA code simulated parameters that were treated deterministically by the PRAISE code. Excellent agreement of numerical results from the two codes was established once the PRO-LOCA code was applied using selective deterministic treatments. Benchmarking efforts described in a related paper have compared calculated frequencies with those estimated from plant operating experience. Sensitivity calculations have also been performed to address uncertainties associated with residual stresses and applied stresses and temperatures. The capabilities and limitations of the two PFM codes are described along with prior PFM applications to piping integrity issues. Model assumptions are described along with the uncertain nature of inputs and their impacts on calculated probabilities. Also described are calculations with the PRAISE code that have used an alternative crack initiation model based on laboratory data for crack initiation by PWSCC in Alloy-182. Sensitivity calculations with this model address the effects of uncertainties in levels of operating and residual stresses, uncertainties in plant operating conditions, and circumferential variations of stress.

Simonen, Fredric A.; Gosselin, Stephen R.; Wilkowski, Gery M.; Rudland, David L.; Xu, H.

2007-07-22

376

Superconducting pipes and levitating magnets  

Microsoft Academic Search

Motivated by a beautiful demonstration of the Faraday and the Lenz laws in which a small neodymium magnet falls slowly through a conducting nonferromagnetic tube, we consider the dynamics of a magnet falling coaxially through a superconducting pipe. Unlike the case of normal conducting pipes, in which the magnet quickly reaches the terminal velocity, inside a superconducting tube the magnet

Yan Levin; Felipe B. Rizzato

2006-01-01

377

Composite material heat pipe radiator  

Microsoft Academic Search

Organic matrix composite material is recognized for its significant strength to weight ratio when compared to metal and consequently was investigated for reducing the mass of heat pipes for future space missions. The particular heat pipe that was constructed and tested was made from an organic matrix composite material applied to a linear of titanium tubing spun to foil thickness

Nelson J. Gernert; David B. Sarraf; Richard J. Guenther

1996-01-01

378

Generator cooling using heat pipes  

Microsoft Academic Search

This paper presents the study of a heat pipe- equipped heat exchanger with two filling ratios of R134a 19 % and 59 %, respectively. The airflow rate varies from 0.4 to 2.0 kg\\/ s. The temperatures at the evaporator side of the heat pipe vary from 40 to 70 °C and at the condenser part from 20 to 50 °C.

Bert de LEEUW; Harry Hagens; Brand van den S; Mart Grooten; FLA Ganzevles; Geld van der CWM; Kemenade van HP

2006-01-01

379

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

380

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

381

Energy performance of plastic pipes  

Microsoft Academic Search

This paper studies the power needed to circulate heating water in building networks using different plastic pipes manufactured in Jordan. A suitable set up was designed and built for this purpose; the study included the effect of the rate of flow and the water temperature. On the basis of the results of pressure drop the pipes were divided as high

M Hammad

1999-01-01

382

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

383

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

384

Building a copper pipe 'xylophone'  

Microsoft Academic Search

Music is central to the life of many students. This article describes using 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-like musical instrument or set of chimes from a 3 m section of copper pipe. The instrument produces a full major scale

David R. Lapp

2003-01-01

385

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

386

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

387

Plans to update benchmarking tool.  

PubMed

The use of the current AssetMark system by hospital health facilities managers and engineers (in Australia) has decreased to a point of no activity occurring. A number of reasons have been cited, including cost, time to do, slow process, and level of information required. Based on current levels of activity, it would not be of any value to IHEA, or to its members, to continue with this form of AssetMark. For AssetMark to remain viable, it needs to be developed as a tool seen to be of value to healthcare facilities managers, and not just healthcare facility engineers. Benchmarking is still a very important requirement in the industry, and AssetMark can fulfil this need provided that it remains abreast of customer needs. The proposed future direction is to develop an online version of AssetMark with its current capabilities regarding capturing of data (12 Key Performance Indicators), reporting, and user interaction. The system would also provide end-users with access to live reporting features via a user-friendly web nterface linked through the IHEA web page. PMID:23513367

Stokoe, Mark

2013-02-01

388

Effect of pipe sags on wastewater collection system performance.  

PubMed

Sagging of pipelines is a common problem in centralized wastewater collection systems. Wastewater flowing through sags experiences several changes of slope, and the flow through flat and negative slope sections is prone to a significant reduction in mean velocity. The objective of this study is to determine when pipe sags would result in significant velocities below design conditions, which also would increase the risk of a sewer backup. A sagged pipe configuration that could be encountered in sanitary sewer systems was depicted; thereby, analyses on uniform and gradually varied flows were conducted to determine velocity profiles through different segments of the sagged pipeline setup used for the study. The results indicate that there are significant occurrences when either the velocity in the pipe sags goes below minimum, as recommended in the Ten States Standards (Health Research, Inc., 2004) (0.61 m/s [2.0 ft/ sec]), or flow depth rises to pipe diameter (full section flow). Additionally, velocities along a sagged pipe were calculated for temporal flow rates to account for daily and seasonal flow rate changes in a typical wastewater collection system. Results of the temporal flow rate analysis suggest that, for a 200-mm (8-in.) diameter sagged pipe segment with full-section (wet weather) flow, 75% of the mean velocities would be below the minimum velocity recommended as a Ten States Standard. PMID:21553591

Sever, V Firat; Foust, Henry

2011-04-01

389

Monitoring pipe line stress due to ground displacement  

SciTech Connect

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

Greenwood, J.H. Jr.

1986-04-01

390

A heat pipe quick disconnect  

NASA Astrophysics Data System (ADS)

This paper reports the proof of concept demonstration of a heat pipe quick disconnect being developed for the space constructible radiator system. The disconnect provides a maintainable coupling between the heat pipe evaporator, which is brazed to a mating heat exchanger, and the replaceable condenser section of a monogroove heat pipe radiator element. Test results, with pressurized nitrogen gas, confirm low leakage rates in both demated and mated configurations. Comparative thermal tests in a working 3 m (10 ft) test bed heat pipe using ammonia fluid revealed a 30 percent decrease in heat transport due to the additional minor pressure losses from the quick disconnect. The bulk of this loss is attributed to the transition section that joins the two adjacent heat pipe flow channels to the separated liquid and vapor passages within the disconnect coupling. It would be possible to decrease this overall loss in heat transport to under 10 percent with a redesigned transition section.

Alario, J. P.; Otterstedt, P. J.

1985-07-01

391

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

392

Prometheus Hot Leg Piping Concept  

NASA Astrophysics Data System (ADS)

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

Gribik, Anastasia M.; Dilorenzo, Peter A.

2007-01-01

393

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

SciTech Connect

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

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

1994-02-01

394

Numisheet2005 Benchmark Analysis on Forming of an Automotive Underbody Cross Member: Benchmark 2  

SciTech Connect

This report presents an international cooperation benchmark effort focusing on simulations of a sheet metal stamping process. A forming process of an automotive underbody cross member using steel and aluminum blanks is used as a benchmark. Simulation predictions from each submission are analyzed via comparison with the experimental results. A brief summary of various models submitted for this benchmark study is discussed. Prediction accuracy of each parameter of interest is discussed through the evaluation of cumulative errors from each submission.

Buranathiti, Thaweepat; Cao Jian [Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208 (United States)

2005-08-05

395

Quality control of plastic pipe at Consumers' Gas  

SciTech Connect

Consumer's Gas, which currently uses over 3.3 million ft/yr of plastic pipe, developed a quality-control program that covers the plastic fittings and heater faces as well as the plastic pipe and tubing itself. A crucial part of the program is materials specifications for each piece of equipment. The practice of circulating new specifications (or specification changes) to the materials supplier for comment allows discussion and possible revision prior to implementation; a preliminary screening procedure involving a thorough materials evaluation avoids many unnecessary quality problems. Rejection rates usually run about 0.9% for pipe and tubing and 2% for fittings. (The atypical rejection of 29% of the heater faces in 1979 was due to the introduction of a new manufacturer and to teflon-coating problems). The removal of defective material before it reaches the field saves time and money in transportation and installation.

Reaney, E.

1980-01-01

396

Benchmarking ENDF/B-VII.0  

SciTech Connect

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 O, Fe, Pb), and Pulsed Sphere experiments at Lawrence Livermore National Laboratory (for {sup 6}Li, {sup 7}Li, Be, C, N, O, Mg, Al, Ti, Fe, Pb, D{sub 2}O, H{sub 2}O, 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.

Marck, Steven C. van der [Nuclear Research and Consultancy Group NRG, P.O. Box, 1755 ZG Petten (Netherlands)]. E-mail: vandermarck@nrg-nl.com

2006-12-15

397

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, D2O, H2O, 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

398

Benchmarking for North Carolina Public Transportation Systems.  

National Technical Information Service (NTIS)

The North Carolina Department of Transportation, Public Transportation Division (NCDOT/PTD) requested recommendations for a benchmarking process for public transportation systems. This request was driven by the need to ensure that transit systems meet the...

J. J. Lawrie T. J. Cook

2006-01-01

399

Toxicological benchmarks for wildlife. Environmental Restoration Program.  

National Technical Information Service (NTIS)

This report presents toxicological benchmarks for assessment of effects of 55 chemicals on six representative mammalian wildlife species (short-tailed shrew, white-footed mouse, cottontail ink, red fox, and whitetail deer) and eight avian wildlife species...

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

1993-01-01

400

Aeroelasticity Benchmark Assessment: Subsonic Fixed Wing Program.  

National Technical Information Service (NTIS)

The fundamental technical challenge in computational aeroelasticity is the accurate prediction of unsteady aerodynamic phenomena and the effect on the aeroelastic response of a vehicle. Currently, a benchmarking standard for use in validating the accuracy...

C. D. Wieseman J. P. Florance P. Chwalowski

2010-01-01

401

Precipitation dendrites in turbulent pipe flows  

NASA Astrophysics Data System (ADS)

Surface precipitation in pipelines, as well as freezing in water pipes is of great concern in many industrial applications where scaling phenomena becomes a control problem of pipe-clogging or an efficiency reduction in transport. Flow blockage often occurs even when only a small fraction is deposited non-uniformly on the walls in the form of dendrites. Dendritic patterns are commonly encountered in surface precipitation from supersaturated solutions, e.g. calcite dendrites, as well as in solidification from undercooled liquids, e.g. freezing of water into ice dendrites. We explore the mathematical similarities between precipitation and freezing processes and, in particular, investigate the effect of fluid flow on the precipitation dendrites on pipe walls. We use a phase field approach to model surface growth coupled with a lattice Boltzmann method that simulates a channel flow at varying Reynolds number. The dendrites orientation and shape depend non-trivially on the ratio between advection and diffusion, i.e. the Peclet number, as well as the Reynolds number. Roughness induced vortices near growing dendrites at high flow rates further affect the branch splitting of dendrites. We show how the transport rate in a pipeline may depend on the different dendritic morphologies, and provide estimates for the flow conditions that correspond to most efficient transport regimes.

Angheluta, Luiza; Hawkins, Christopher; Hammer, Øyvind; Jamtveit, Bjørn

2013-04-01

402

Transient flows and pressure waves in pipes  

NASA Astrophysics Data System (ADS)

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

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

403

CommBench-a telecommunications benchmark for network processors  

Microsoft Academic Search

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

Tilman Wolf; Mark Franklin

2000-01-01

404

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

405

A synergistic performance management model conjoining benchmarking and motivation  

Microsoft Academic Search

Purpose – The purpose of this paper is to develop an improved management\\/performance model that yields superior business productivity by conjoining internal benchmarking, external benchmarking, and a strong employee performance\\/behavior paradigm. Design\\/methodology\\/approach – Strengths and weaknesses of conventional benchmarking approaches to productivity maximization are examined through both literature surveys and experiments. Findings – It is found that most benchmarking efforts

Anatoliy G. Goncharuk; Jamie P. Monat

2009-01-01

406

A framework for benchmarking land models  

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

407

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

408

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

409

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

410

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

411

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

412

Cache Performance of the SPEC Benchmark Suite  

Microsoft Academic Search

The SPEC benchmark suite consists of ten public-domain, non-trivial programs that are widely used to measure the performance of computer systems, particularly those in the Unix workstation market. These benchmarks were expressly chosen to represent real-world applications and were intended to be large enough to stress the computational and memory system resources of current-generation machines. The extent to which the

Jeffrey D. Gee; Mark D. Hill; Dionisios N. Pnevmatikatos; Alan Jay Smith

1991-01-01

413

Benchmark Tests of Radiation Transport Computer Codes for Reactor Core and Shield Calculations  

Microsoft Academic Search

Aiming at providing test problems that may be used to verify an adequate performance of the current version of a neutron and ?-ray transport computer code used for reactor core or shield calculations, we summarize the input data and the calculated results for three benchmark problems.The 1st problem deals with a 1-dimensional small spherical reactor for use to test 1-dimensional

Takumi ASAOKA; Norio ASANO; Hisashi NAKAMURA; Hiroshi MIZUTA; Hiroshi CHICHIWA; Tadahiro OHNISHI; Shun-ichi MIYASAKA; Atsushi ZUKERAN; Tsuneo TSUTSUI; Toichiro FUJIMURA; Satoru KATSURAGI

1978-01-01

414

Acoustic technique for tracing plastic pipe  

SciTech Connect

Many gas distribution company operation and maintenance activities require precise knowledge of the location of buried plastic piping. Under sponsorship of the Southern California Gas Company, IGT successfully demonstrated an acoustic plastic pipe location technique and is developing that technique into a practical field instrument. An acoustic signal is injected into the plastic pipe such that it propagates through the pipe. As the acoustic wave travels along the pipe, some of the sound radiates from the pipe to the surface of the ground. An array of sensors on the surface of the ground perpendicular to the pipe detects the acoustic signal, thereby locating the pipe. Two different acoustic measurements are used. The first measurement locates the pipe to within + 1.2 m (+ 4.0 ft). The second technique then determines the location of the pipe to within + 15 cm (+ 6 in.) and gives an estimate of pipe depth.

Huebler, J.E.; Campbell, B.K. [Institute of Gas Technology, Chicago, IL (United States); Ching, G.K. [Southern California Gas Co., Los Angeles, CA (United States)

1992-12-31

415

Acoustic technique for tracing plastic pipe  

SciTech Connect

Many gas distribution company operation and maintenance activities require precise knowledge of the location of buried plastic piping. Under sponsorship of the Southern California Gas Company, IGT successfully demonstrated an acoustic plastic pipe location technique and is developing that technique into a practical field instrument. An acoustic signal is injected into the plastic pipe such that it propagates through the pipe. As the acoustic wave travels along the pipe, some of the sound radiates from the pipe to the surface of the ground. An array of sensors on the surface of the ground perpendicular to the pipe detects the acoustic signal, thereby locating the pipe. Two different acoustic measurements are used. The first measurement locates the pipe to within + 1.2 m (+ 4.0 ft). The second technique then determines the location of the pipe to within + 15 cm (+ 6 in.) and gives an estimate of pipe depth.

Huebler, J.E.; Campbell, B.K. (Institute of Gas Technology, Chicago, IL (United States)); Ching, G.K. (Southern California Gas Co., Los Angeles, CA (United States))

1992-01-01

416

Benchmarking regulatory network reconstruction with GRENDEL  

PubMed Central

Motivation: Over the past decade, the prospect of inferring networks of gene regulation from high-throughput experimental data has received a great deal of attention. In contrast to the massive effort that has gone into automated deconvolution of biological networks, relatively little effort has been invested in benchmarking the proposed algorithms. The rate at which new network inference methods are being proposed far outpaces our ability to objectively evaluate and compare them. This is largely due to a lack of fully understood biological networks to use as gold standards. Results: We have developed the most realistic system to date that generates synthetic regulatory networks for benchmarking reconstruction algorithms. The improved biological realism of our benchmark leads to conclusions about the relative accuracies of reconstruction algorithms that are significantly different from those obtained with A-BIOCHEM, an established in silico benchmark. Availability: The synthetic benchmark utility and the specific benchmark networks that were used in our analyses are available at http://mblab.wustl.edu/software/grendel/ Contact: brent@cse.wustl.edu

Haynes, Brian C.; Brent, Michael R.

2009-01-01

417

Quality measures for protein alignment benchmarks  

PubMed Central

Multiple protein sequence alignment methods are central to many applications in molecular biology. These methods are typically assessed on benchmark datasets including BALIBASE, OXBENCH, PREFAB and SABMARK, which are important to biologists in making informed choices between programs. In this article, annotations of domain homology and secondary structure are used to define new measures of alignment quality and are used to make the first systematic, independent evaluation of these benchmarks. These measures indicate sensitivity and specificity while avoiding the ambiguous residue correspondences and arbitrary distance cutoffs inherent to structural superpositions. Alignments by selected methods that indicate high-confidence columns (ALIGN-M, DIALIGN-T, FSA and MUSCLE) are also assessed. Fold space coverage and effective benchmark database sizes are estimated by reference to domain annotations, and significant redundancy is found in all benchmarks except SABMARK. Questionable alignments are found in all benchmarks, especially in BALIBASE where 87% of sequences have unknown structure, 20% of columns contain different folds according to SUPERFAMILY and 30% of ‘core block’ columns have conflicting secondary structure according to DSSP. A careful analysis of current protein multiple alignment benchmarks calls into question their ability to determine reliable algorithm rankings.

Edgar, Robert C.

2010-01-01

418

Action-Oriented Benchmarking: Concepts and Tools  

SciTech Connect

Most energy benchmarking tools provide static feedback on how one building compares to a larger set of loosely similar buildings, without providing information at the end-use level or on what can be done to reduce consumption, cost, or emissions. In this article--Part 1 of a two-part series--we describe an 'action-oriented benchmarking' approach, which extends whole-building energy benchmarking to include analysis of system and component energy use metrics and features. Action-oriented benchmarking thereby allows users to generate more meaningful metrics and to identify, screen and prioritize potential efficiency improvements. This opportunity assessment process can then be used to inform and optimize a full-scale audit or commissioning process. We introduce a new web-based action-oriented benchmarking system and associated software tool-EnergyIQ. The benchmarking methods, visualizations, and user interface design are informed by an end-user needs assessment survey and best-practice guidelines from ASHRAE.

California Energy Commission; Mathew, Paul; Mills, Evan; Mathew, Paul; Piette, Mary Ann; Bourassa, Norman; Brook, Martha

2008-02-13

419

Pool critical assembly pressure vessel facility benchmark  

SciTech Connect

This pool critical assembly (PCA) pressure vessel wall facility benchmark (PCA benchmark) is described and analyzed in this report. Analysis of the PCA benchmark can be used for partial fulfillment of the requirements for the qualification of the methodology for pressure vessel neutron fluence calculations, as required by the US Nuclear Regulatory Commission regulatory guide DG-1053. Section 1 of this report describes the PCA benchmark and provides all data necessary for the benchmark analysis. The measured quantities, to be compared with the calculated values, are the equivalent fission fluxes. In Section 2 the analysis of the PCA benchmark is described. Calculations with the computer code DORT, based on the discrete-ordinates method, were performed for three ENDF/B-VI-based multigroup libraries: BUGLE-93, SAILOR-95, and BUGLE-96. An excellent agreement of the calculated (C) and measures (M) equivalent fission fluxes was obtained. The arithmetic average C/M for all the dosimeters (total of 31) was 0.93 {+-} 0.03 and 0.92 {+-} 0.03 for the SAILOR-95 and BUGLE-96 libraries, respectively. The average C/M ratio, obtained with the BUGLE-93 library, for the 28 measurements was 0.93 {+-} 0.03 (the neptunium measurements in the water and air regions were overpredicted and excluded from the average). No systematic decrease in the C/M ratios with increasing distance from the core was observed for any of the libraries used.

Remec, I.; Kam, F.B.K. [Oak Ridge National Lab., TN (United States)

1997-07-01

420

Quantitative prediction of reduction in large pipe setting round process  

NASA Astrophysics Data System (ADS)

The control manner during the process to ensure the quality of pipe products mainly relies on the operator's experience, so it is very necessary to study the setting round process and obtain its spring-back law. The setting round process is shaping an oval section pipe into circular section, so it is difficult to provide a quantificational analysis for its spring-back process because of the curvature inequality of pipe section neutral layer. However, the spring-back law of the circle-oval process can be easily predicted. The experimental method is firstly used to establish the equivalent effect between the setting round process and the circle-oval process. The setting round process can be converted into the circle-oval process. There are two difficulties in the theoretical analysis for the circle-oval process: elastic-plastic bending problem of curved beam; statically indeterminate problem. A quantitative analytic method for the circle-oval process is presented on the basis of combination of the spring-back law of plane curved beam with the element dividing idea in finite element method. The ovality after unloading versus the relative reduction is plotted with analytical and experimental results respectively, which shows a fair agreement. Finally, the method of quantitative prediction of reduction for large pipe setting round is given based on the equivalent effect and the analytical results. Five pipes, which are needed to be set round, are used to carry out experiment so as to verify this method. The results of verification experiment indicates that, in the experimental range, the residual ovality are all under 0.35% after the once only setting round with the theoretical prediction reductions. It is much less than the 1% requirement of pipe standard. Applying the established theoretical analysis is able to correct the pipe ovality with sufficient accuracy, which provides theoretical direction to plant use.

Zhao, Jun; Zhan, Peipei; Ma, Rui; Zhai, Ruixue

2013-07-01

421

Excitation and scattering of guided waves: relationships between solutions for plates and pipes.  

PubMed

The detection of localized defects such as cracks and corrosion in pipes using guided elastic waves is now an established non-destructive testing procedure. However, the prediction of guided wave excitation and scattering in pipes is a complex three-dimensional (3D) problem with many parameters that can generally only be solved using numerical methods. In many important industrial applications, the diameter of a pipe is much larger than wall thickness. In this case an 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 is extended to relate guided wave scattering from defects in plates to scattered circumferential modal amplitudes from defects in pipe. This is of practical benefit as the scattering of guided waves by defects in a plate is a much simpler problem than that in a pipe, and one that, in some cases, can be solved using analytical methods. Results are shown that illustrate the application of the method to reflection from through-thickness circumferential cracks in pipes. PMID:19507944

Velichko, Alexander; Wilcox, Paul D

2009-06-01

422

The skyshine benchmark experiment revisited.  

PubMed

With the coming renaissance of nuclear power, heralded by new nuclear power plant construction in Finland, the issue of qualifying modern tools for calculation becomes prominent. Among the calculations required may be the determination of radiation levels outside the plant owing to skyshine. For example, knowledge of the degree of accuracy in the calculation of gamma skyshine through the turbine hall roof of a BWR plant is important. Modern survey programs which can calculate skyshine dose rates tend to be qualified only by verification with the results of Monte Carlo calculations. However, in the past, exacting experimental work has been performed in the field for gamma skyshine, notably the benchmark work in 1981 by Shultis and co-workers, which considered not just the open source case but also the effects of placing a concrete roof above the source enclosure. The latter case is a better reflection of reality as safety considerations nearly always require the source to be shielded in some way, usually by substantial walls but by a thinner roof. One of the tools developed since that time, which can both calculate skyshine radiation and accurately model the geometrical set-up of an experiment, is the code RANKERN, which is used by Framatome ANP and other organisations for general shielding design work. The following description concerns the use of this code to re-address the experimental results from 1981. This then provides a realistic gauge to validate, but also to set limits on, the program for future gamma skyshine applications within the applicable licensing procedures for all users of the code. PMID:16604694

Terry, Ian R

2005-01-01

423

Updating pipe insulation  

SciTech Connect

Every plant engineer knows that proper insulation saves energy. The right insulation also increases plant yields and capacity without capital expansion. Field experience has shown that proper insulation, a combination of the right material, thickness, and jacketing helps maintain optimum temperatures throughout a process. The result is processes that safely run hotter and faster, and produce more acceptable product. In hydrocarbon processing, for example, insulating fuel, lubricant, and petrochemical lines helps ensure more premium-grade product. In power generation, better insulation means more saleable electricity per ton of fuel. In chemical processing, properly insulating process heat lines for reactor vessels and turbines means consistent product and less scrap. The same holds true for pulp and paper processing (especially at the pulping end), textile manufacturing, and food processing. This paper briefly explains a 5-step program to help a plant engineer determine the plant's pipe insulation requirements.

Rickards, D. (CertainTeed Corp., Valley Forge, PA (United States))

1993-03-04

424

Pipe initiation anchor  

SciTech Connect

In a pipe initiation anchor for forming a fixed anchor point for use in laying underwater pipelines, this patent described the combination of: a frame; a ground engaging member; means for attaching the frame to the ground engaging member; and socket means carried in the frame defining a socket for receiving and retaining the end portion of the pipeline within the socket. The socket means include first and second generally horizontal bars, with the first bar mounted in the frame and with the second bar mounted on a pivoting member in the frame and spaced from the first bar, and a counter-balance weight carried on the pivoting member urging the second bar toward the first bar.

Morris, G.A.

1987-10-27

425

Superconducting pipes and levitating magnets.  

PubMed

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

Levin, Yan; Rizzato, Felipe B

2006-12-12

426

Turbulent heat transfer for pipe flow with uniform heat generation  

Microsoft Academic Search

An Analytic solution is presented of the problem of turbulent heat transfer in pipes with internal heat generation and insulated wall by applying a recently-developed eddy conductivity model. The results agree closely with available experimental data for a wide range of Prandtl number (0.02–10.5).

T. Y. Na; J. P. Chiou

1979-01-01

427

Flat plate loop heat pipe with a novel evaporator structure  

Microsoft Academic Search

The paper proposes the fabrication and test of flat plate loop heat pipe (FPLHP) with a novel evaporator structure. The IC industry of Taiwan, ROC is one of the most competitive industries in the world. With the increase in electric heat dissipation and miniaturization, we need advanced cooling systems to solve the high temperature problems. We describe the evaporator design

Meng-Chang Tsai; Chun-Sheng Yu; Shung-Wen Kang

2005-01-01

428

Equations shorten pipe collapse calculations  

SciTech Connect

The API suggests collapse pressure equations for long, perfectly round, steel oil field casing, tubing, drill pipe, and line pipe. Operating and service company engineers can substitute two pipe collapse pressure equations for the 12 API equations now in general use. The shorthand results are almost the same as those from the API equations. The shorthand method has the additional advantage of allowing units from any measurement system. The API equations restrict calculations to US units only. The equation box lists the API (Equations 1--12) and the shorthand (Equations 13--14) equations. The API equations are based on work started shortly after the turn of the century.

Avakov, V.A. [Halliburton Energy Services, Duncan, OK (United States)

1995-04-10

429

Determination of Secondary Encasement Pipe Design Pressure  

SciTech Connect

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

TEDESCHI, A.R.

2000-10-26

430

Thermal performance of insulated pipe systems  

Microsoft Academic Search

The thermal performance of insulated pipe systems was measured as a function of insulation and pipe system parameters. Insulation parameters included insulation material, thickness, and air gaps at seams and joints. Pipe system parameters were pipe size, hangers, supports, and operating temperature. Over 150 thermal performance tests were recorded and analyzed over a two-year period. Test results show a 15

1981-01-01

431

Thermal performance of insulated pipe systems  

Microsoft Academic Search

The thermal performance of insulated pipe systems was measured as a function of insulation and pipe system parameters. Insulation parameters included insulation material, thickness, and air gaps at seams and joints. Pipe system parameters were pipe size, hangers, supports, and operating temperature. Over 150 thermal performance tests were recorded and analyzed over a two-year period. Test results show a 15%

J. M. Jr

1983-01-01

432

Pipe insulating system and apparatus therefor  

Microsoft Academic Search

A system is described for insulating pipe with a foamed material, such as polyurethane, which includes an apparatus for forming a mold about the pipe into which the foam may be injected, apparatus for propelling the pipe through the mold, and support rollers for supporting the pipe before the foam sets without damaging or permanently deforming the foamed insulation. The

Baughmann

1975-01-01

433

Heat pipe experiment on SPAS 01  

NASA Astrophysics Data System (ADS)

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

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

1986-08-01

434

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

435

Heat pipes and their technical applications  

Microsoft Academic Search

A general review paper on heat pipes is presented with attention given to principles of operation. Also considered are transfer processes in heat-pipe wicks, the effect of the structural characteristics of a wick on convective transfer of the working fluid, and heat and mass transfer in the wicks of low-temperature heat pipes. Applications of heat pipes in such fields as

L. L. Vasilev

1976-01-01

436

Grey Cast Iron Water Pipe Metallurgy  

Microsoft Academic Search

The results of a metallographic study of grey cast iron water pipes are reported. These pipes had been installed between 1885 and 1973 in eight different water systems. Each pipe had been extracted during scheduled maintenance or failure repairs to provide data for a larger study to produce a methodology for determining the residual life of grey cast iron pipes.

J. M. Makar; B. Rajani

437

Recent advances in pipe support design  

SciTech Connect

This conference proceedings contains 10 papers. The topics covered include: analysis of base plates; design of pipe restraint end attachments; analysis of rigid struts; computer aided design of pipe supports; loading on connection angle clips; column to support nuclear piping systems; velocity sensitive hydraulic snubbers; load characteristics of pipe clamps. One paper is abstracted separately.

van Stijgeren, E.

1982-01-01

438

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

439

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2011 CFR

...Transportation 3 2011-10-01 2011-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper pipe...

2011-10-01

440

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2010 CFR

...Transportation 3 2009-10-01 2009-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper pipe...

2009-10-01

441

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2012 CFR

...Transportation 3 2012-10-01 2012-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper pipe...

2012-10-01

442

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2010 CFR

...Transportation 3 2010-10-01 2010-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper pipe...

2010-10-01

443

Seismic Proving Test of Eroded Piping (Status of Eroded Piping Component and System Test)  

Microsoft Academic Search

In FY 2000, a 3-year testing program of eroded piping was initiated with the following objectives: 1) to ascertain the seismic safety margins for eroded piping designed under the current seismic design code, 2) to clarify the elasto-plastic response and ultimate strength of eroded nuclear piping. A series of tests on eroded piping components and eroded piping systems was planned.

Y. Namita; K. Suzuki; H. Abe; I. Ichihashi; M. Shiratori; K. Iwata; A. Nebu

444

A Comparison of Monte Carlo Particle Transport Algorithms for an Interior Source Binary Stochastic Medium Benchmark Suite  

SciTech Connect

Particle transport through binary stochastic mixtures has received considerable research attention in the last two decades. Zimmerman and Adams proposed a Monte Carlo algorithm (Algorithm A) that solves the Levermore-Pomraning equations and another Monte Carlo algorithm (Algorithm B) that should be more accurate as a result of improved local material realization modeling. Zimmerman and Adams numerically confirmed these aspects of the Monte Carlo algorithms by comparing the reflection and transmission values computed using these algorithms to a standard suite of planar geometry binary stochastic mixture benchmark transport solutions. The benchmark transport problems are driven by an isotropic angular flux incident on one boundary of a binary Markovian statistical planar geometry medium. In a recent paper, we extended the benchmark comparisons of these Monte Carlo algorithms to include the scalar flux distributions produced. This comparison is important, because as demonstrated, an approximate model that gives accurate reflection and transmission probabilities can produce unphysical scalar flux distributions. Brantley and Palmer recently investigated the accuracy of the Levermore-Pomraning model using a new interior source binary stochastic medium benchmark problem suite. In this paper, we further investigate the accuracy of the Monte Carlo algorithms proposed by Zimmerman and Adams by comparing to the benchmark results from the interior source binary stochastic medium benchmark suite, including scalar flux distributions. Because the interior source scalar flux distributions are of an inherently different character than the distributions obtained for the incident angular flux benchmark problems, the present benchmark comparison extends the domain of problems for which the accuracy of these Monte Carlo algorithms has been investigated.

Brantley, P S

2009-06-30

445

USS PRINCETON (CG59): Microbiologically Influenced Corrosion (MIC) and Macrofouling Status of Seawater Piping Systems.  

National Technical Information Service (NTIS)

This report summarizes the microfouling and macrofouling within the seawater piping system of the USS PRINCETON (CG59) and assesses their contribution to the failures/corrosion problems observed. Sulfate reducing bacteria (SRB) were isolated from two test...

J. M. Jones B. Little

1990-01-01

446

Benchmarking, Profiling and Performance Analysis of the Java Grande Benchmarking Suite  

Microsoft Academic Search

In previous papers a number of issues concerning the Java Grande Benchmarking suite have been raised. This paper hopes to examine these issues by conducting a new set of benchmarks and analysing the results. It then investigates the relationship between bench- marks within the suite, while reviewing the various profiling utilities available for Java. Finally, it discusses the design and

Robin Freeman

447

Benchmarking local healthcare-associated infections: Available benchmarks and interpretation challenges.  

PubMed

Growing numbers of healthcare facilities are routinely collecting standardized data on healthcare-associated infection (HAI), which can be used not only to track internal performance but also to compare local data to national and international benchmarks. Benchmarking overall (crude) HAI surveillance metrics without accounting or adjusting for potential confounders can result in misleading conclusions. Methods commonly used to provide risk-adjusted metrics include multivariate logistic regression analysis, stratification, indirect standardization, and restrictions. The characteristics of recognized benchmarks worldwide, including the advantages and limitations are described. The choice of the right benchmark for the data from the Gulf Cooperation Council (GCC) states is challenging. The chosen benchmark should have similar data collection and presentation methods. Additionally, differences in surveillance environments including regulations should be taken into consideration when considering such a benchmark. The GCC center for infection control took some steps to unify HAI surveillance systems in the region. GCC hospitals still need to overcome legislative and logistic difficulties in sharing data to create their own benchmark. The availability of a regional GCC benchmark may better enable health care workers and researchers to obtain more accurate and realistic comparisons. PMID:23999329

El-Saed, Aiman; Balkhy, Hanan H; Weber, David J

2013-06-05

448

Reference solutions for 3-D radiation transport benchmarks by a Monte Carlo code GMVP  

Microsoft Academic Search

Reference Solutions for the 3-D transport benchmark problems proposed by Kobayashi are presented. They were obtained by the multigroup Monte Carlo code GMVP with the point-detector estimator. The statistical uncertainties (1?) are less than 1% at all the calculation points. The GMVP results show good agreement with the analytical solutions by Kobayashi and the MCNP solutions for the pure absorber

Yasunobu Nagaya

2001-01-01

449

SABmark- a benchmark for sequence alignment that covers the entire known fold space  

Microsoft Academic Search

Summary: The Sequence Alignment Benchmark (SABmark) provides sets of multiple alignment problems derived from the SCOP classifica- tion. These sets, Twilight Zone and Superfamilies, both cover the entire known fold space using sequences with very low to low, and low to intermediate similarity, respectively. In addition, each set has an altern- ate version in which unalignable but apparently similar sequences

Ivo Van Walle; Ignace Lasters; Lode Wyns

2005-01-01

450

Benchmark Calculations by the Nuclear Criticality Safety Analysis Code System JACS(MGCL, KENO-IV).  

National Technical Information Service (NTIS)

Since 1980, as many as 1394 cases of benchmark calculations on criticality problems have been performed by the KENO-IV Monte Carlo calculation code with the MGCL cross section data library. The code system is a part of the criticality safety evaluation co...

Y. Nomura J. Katakura Y. Naito Y. Komuro H. Okuno

1986-01-01

451

Plantwide control system design of the benchmark vinyl acetate monomer production plant  

Microsoft Academic Search

This paper addresses control system design of the vinyl acetate monomer production plant that has been introduced as a plantwide control benchmark problem by Luyben et al. Nonlinear analysis of a simplified model, which includes detailed reactor behavior and ideal separation with gas and liquid recycle, is performed to identify the optimal operating condition and to develop intuition for control

Hiroya Seki; Morimasa Ogawa; Toshiaki Itoh; Shigeki Ootakara; Hisashi Murata; Yoshihiro Hashimoto; Manabu Kano

2010-01-01

452

Benchmark calculation for a sodium-cooled fast reactor by a three-dimensional variational code  

Microsoft Academic Search

A new numerical approach is attempted and presented in this paper in order to solve the three-dimensional multigroup diffusion equation in rectangular geometry using the principles of variational calculus. The effect of separation of variables is also studied. Detailed calculations are performed for a benchmark problem and the results are presented along with published values that are calculated using finite

Srinivasan

1981-01-01

453

Design and Implementation of the HPCS Graph Analysis Benchmark on Symmetric Multiprocessors  

Microsoft Academic Search

Graph theoretic problems are representative of fundamental computations in tra- ditional and emerging scientific disciplines like scientific computing, computational biology and bioinformatics, as well as applications in national security. We present our design and implementation of a graph theory application that supports the kernels from the Scalable Synthetic Compact Applications (SSCA) benchmark suite, devel- oped under the DARPA High Productivity

David A. Baderand; Kamesh Madduri

2005-01-01

454

A benchmark server using high resolution protein structure data, and benchmark results for membrane helix predictions  

PubMed Central

Background Helical membrane proteins are vital for the interaction of cells with their environment. Predicting the location of membrane helices in protein amino acid sequences provides substantial understanding of their structure and function and identifies membrane proteins in sequenced genomes. Currently there is no comprehensive benchmark tool for evaluating prediction methods, and there is no publication comparing all available prediction tools. Current benchmark literature is outdated, as recently determined membrane protein structures are not included. Current literature is also limited to global assessments, as specialised benchmarks for predicting specific classes of membrane proteins were not previously carried out. Description We present a benchmark server at http://sydney.edu.au/pharmacy/sbio/software/TMH_benchmark.shtml that uses recent high resolution protein structural data to provide a comprehensive assessment of the accuracy of existing membrane helix prediction methods. The server further allows a user to compare uploaded predictions generated by novel methods, permitting the comparison of these novel methods against all existing methods compared by the server. Benchmark metrics include sensitivity and specificity of predictions for membrane helix location and orientation, and many others. The server allows for customised evaluations such as assessing prediction method performances for specific helical membrane protein subtypes. We report results for custom benchmarks which illustrate how the server may be used for specialised benchmarks. Which prediction method is the best performing method depends on which measure is being benchmarked. The OCTOPUS membrane helix prediction method is consistently one of the highest performing methods across all measures in the benchmarks that we performed. Conclusions The benchmark server allows general and specialised assessment of existing and novel membrane helix prediction methods. Users can employ this benchmark server to determine the most suitable method for the type of prediction the user needs to perform, be it general whole-genome annotation or the prediction of specific types of helical membrane protein. Creators of novel prediction methods can use this benchmark server to evaluate the performance of their new methods. The benchmark server will be a valuable tool for researchers seeking to extract more sophisticated information from the large and growing protein sequence databases.

2013-01-01

455

Nitrogen heat pipe for cryocooler thermal shunt  

SciTech Connect

A nitrogen heat pipe was designed, built and tested for the purpose of providing a thermal shunt between the two stages of a Gifford-McMahan (GM) cryocooler during cooldown. The nitrogen heat pipe has an operating temperature range between 63 and 123 K. While the heat pipe is in the temperature range during the system cooldown, it acts as a thermal shunt between the first and second stage of the cryocooler. The heat pipe increases the heat transfer to the first stage of the cryocooler, thereby reducing the cooldown time of the system. When the heat pipe temperature drops below the triple point, the nitrogen working fluid freezes, effectively stopping the heat pipe operation. A small heat leak between cryocooler stages remains because of axial conduction along the heat pipe wall. As long as the heat pipe remains below 63 K, the heat pipe remains inactive. Heat pipe performance limits were measured and the optimum fluid charge was determined.

Prenger, F.C.; Hill, D.D.; Daney, D.E.; Daugherty, M.A. [Los Alamos National Lab., NM (United States); Green, G.F.; Roth, E.W. [Naval Surface Warfare Center, Annapolis, MD (United States)

1995-09-01

456

Action-Oriented Benchmarking: Using the CEUS Database to Benchmark Commercial Buildings in California  

SciTech Connect

The 2006 Commercial End Use Survey (CEUS) database developed by the California Energy Commission is a far richer source of energy end-use data for non-residential buildings than has previously been available and opens the possibility of creating new and more powerful energy benchmarking processes and tools. In this article--Part 2 of a two-part series--we describe the methodology and selected results from an action-oriented benchmarking approach using the new CEUS database. This approach goes beyond whole-building energy benchmarking to more advanced end-use and component-level benchmarking that enables users to identify and prioritize specific energy efficiency opportunities - an improvement on benchmarking tools typically in use today.

Mathew, Paul; Mills, Evan; Bourassa, Norman; Brook, Martha

2008-02-01

457

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

Microsoft Academic Search

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

?efik Bilir

2002-01-01

458

Laminar flow heat transfer in pipes including two-dimensional wall and fluid axial conduction  

Microsoft Academic Search

An analysis is made for a conjugate heat transfer problem with thermally developing laminar pipe flow, involving two-dimensional wall and axial fluid conduction. The problem is solved numerically by a finite-difference method for a thick walled, two-regional pipe which has constant outside surface temperatures interfaced by a step change. An exact profile is used to discretize the differential equation in

?ef?k B?l?r

1995-01-01

459

B Plant process piping replacement feasibility study  

SciTech Connect

Reports on the feasibility of replacing existing embedded process piping with new more corrosion resistant piping between cells and between cells and a hot pipe trench of a Hanford Site style canyon facility. Provides concepts for replacement piping installation, and use of robotics to replace the use of the canyon crane as the primary means of performing/supporting facility modifications (eg, cell lining, pipe replacement, equipment reinstallation) and operational maintenenace.

Howden, G.F.

1996-02-07

460

Protection cover for pipe bends  

US Patent & Trademark Office Database

A protection cover for pipe bends produced from a plastic material by deep drawing into a shape which is similar to the shape which could be obtained if an integral and complete cover installed on a pipe bend had been cut along the interior generatrics line of the pipe bend and spread apart and opened up. The shape of the present protection cover is further modified by having a cup-shaped part generally elongated and rounded in transverse cross-section and having integral therewith tail sections located at each short side of the cup-shaped part. Each of the tail sections have a concave bend therein. The overall shape of the protection cover is such that when the cover is applied over an insulated pipe bend, the cover will have on its interior side a curvature radius that is essentially greater than the curvature radius of its exterior side, and the two curvature radii will have mutually different centers.

1976-06-01

461

Idea Bank: Pipe Cleaner DNA  

NSDL National Science Digital Library

The pipe cleaner DNA model uses simple materials, but offers limitless opportunities for realistic manipulation, including DNA replication, mutation, and protein synthesis. The activity is also appropriate for students at many levels.

Rosenkrantz, Kurt

2004-05-01

462

Corrugated pipe adhesive applicator apparatus  

DOEpatents

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

Shirey, Ray A. (North Grafton, MA)

1983-06-14

463

Corrugated pipe adhesive applicator apparatus  

DOEpatents

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

Shirey, R.A.

1983-06-14

464

Heat Pipe Applications Workshop Report.  

National Technical Information Service (NTIS)

The proceedings of the Heat Pipe Applications Workshop, held at the Los Alamos Scientific Laboratory October 20-21, 1977, are reported. This workshop, which brought together representatives of the Department of Energy and of a dozen industrial organizatio...

W. A. Ranken

1978-01-01

465

Benchmarking PSI-BLAST in genome annotation.  

PubMed

The recognition of remote protein homologies is a major aspect of the structural and functional annotation of newly determined genomes. Here we benchmark the coverage and error rate of genome annotation using the widely used homology-searching program PSI-BLAST (position-specific iterated basic local alignment search tool). This study evaluates the one-to-many success rate for recognition, as often there are several homologues in the database and only one needs to be identified for annotating the sequence. In contrast, previous benchmarks considered one-to-one recognition in which a single query was required to find a particular target. The benchmark constructs a model genome from the full sequences of the structural classification of protein (SCOP) database and searches against a target library of remote homologous domains (<20 % identity). The structural benchmark provides a reliable list of correct and false homology assignments. PSI-BLAST successfully annotated 40 % of the domains in the model genome that had at least one homologue in the target library. This coverage is more than three times that if one-to-one recognition is evaluated (11 % coverage of domains). Although a structural benchmark was used, the results equally apply to just sequence homology searches. Accordingly, structural and sequence assignments were made to the sequences of Mycoplasma genitalium and Mycobacterium tuberculosis (see http://www.bmm.icnet. uk). The extent of missed assignments and of new superfamilies can be estimated for these genomes for both structural and functional annotations. PMID:10547299

Müller, A; MacCallum, R M; Sternberg, M J

1999-11-12

466

Development of high performance sintered powder metal wick cryogenic heat pipes  

NASA Astrophysics Data System (ADS)

This paper presents recent development efforts at Eastman Kodak and Thermacore in the area of design, analysis, and testing of cryogenic heat pipes. Two nitrogen heat pipes designed to operate near 80K were designed, built and tested. The first heat pipe was 0.96 meters long and used a sintered homogeneous powder wick that demonstrated a heat transport capability of 3.5 watts at approximately 80K. The second heat pipe was 0.95 meters long with a sintered artery wick that demonstrated a capability of 20 to 25 watts at 0.004 m against gravity at 95K. The cryogenic arterial heat pipe represents an advance in heat pipe technology; twenty-fold improvement in performance is possible compared to a sintered homogeneous powder metal wick. The improvement results from use of a boiling-resistant artery design employing sintered wick technology. Also presented are support equipment requirements and special problems associated with the testing of cryogenic heat pipes. Some of the unique aspects of cryogenic heat pipes include initial start-up and priming of the system, control of system heat leaks, and determining optimum fluid charge for the heat pipe.

Compagna, G. L.; Rosenfeld, J. H.

1988-06-01

467

DETERMINATION OF PHASE WETTING IN OIL-WATER PIPE FLOWS  

Microsoft Academic Search

Oil-water two-phase flow often presents a internal corrosion problem in pipeline transportation. The corrosion rate of the mild steel line is closely related to which phase wets the pipe wall. The problem has been investigated here on a large scale, in a 60 meter-long flow loop with crude oils. In this paper extensive experimental studies of flow pattern as well

François Ayello; Chong Li; Xuanping Tang; Jiyong Cai; Srdjan Nesic; C. Cruz; Jamal N. Al-Khamis

2008-01-01

468

Light Pipe Energy Savings Calculator  

NASA Astrophysics Data System (ADS)

Dependence on fossil fuels is unsustainable and therefore a shift to renewable energy sources such as sunlight is required. Light pipes provide a way to utilize sunlight for interior lighting, and can reduce the need for fossil fuel-generated electrical energy. Because consumers considering light pipe installation may be more strongly motivated by cost considerations than by sustainability arguments, an easy means to examine the corresponding costs and benefits is needed to facilitate informed decision-making. The purpose of this American Physical Society Physics and Society Fellowship project is to create a Web-based calculator to allow users to quantify the possible cost savings for their specific light pipe application. Initial calculations show that the illumination provided by light pipes can replace electric light use during the day, and in many cases can supply greater illumination levels than those typically given by electric lighting. While the installation cost of a light pipe is significantly greater than the avoided cost of electricity over the lifetime of the light pipe at current prices, savings may be realized if electricity prices increase.

Owens, Erin; Behringer, Ernest R.

2009-04-01

469

LARGE-BORE PIPE DECONTAMINATION  

SciTech Connect

The decontamination and characterization of large-bore pipe is difficult because of the various geometries and diameters of pipe and its different material types. A robust decontamination system must be capable of adapting to different pipe diameters (project scope is 6 inches to 24 inches), cleaning surfaces with various surface conditions and material types (i.e., painted, rusted, carbon steel, or stainless steel), and be cost-effective to operate and maintain. The characterization system must be capable of handling the different pipe parameters and detecting contamination on the inside and outside surfaces. It must also operate in a cost-effective manner. Current technology options do not provide a robust system to meet these objectives. The purpose of this project is to verify the need for this technology through determining quantities of pipe available for decontamination (completed FY97), perform a technology screening process to select technologies for decontamination (completed FY97) and characterization (completed FY98), perform treatability studies to collect required performance data (completed FY97), and design and fabricate a prototype system to decontaminate and characterize the internal and external surfaces of large-bore pipe. A field mobile system capable of performing decontamination and characterization operations will be the main deliverable for this project. A summary of activities completed during FY97 is provided to understand the project development and implementation process.

M.A. Ebadian

1999-01-01

470

Composite material heat pipe radiator  

SciTech Connect

Organic matrix composite material is recognized for its significant strength to weight ratio when compared to metal and consequently was investigated for reducing the mass of heat pipes for future space missions. The particular heat pipe that was constructed and tested was made from an organic matrix composite material applied to a linear of titanium tubing spun to foil thickness (0.076 mm). The thin liner transitioned to heavier-walled ends which allowed the tubing to be sealed using conventional welding. More specifically, the heat pipe was 1.14 m long, 24 mm in diameter and had a mass of 0.165 kg. Water was the working fluid. The heat pipe was tested in a Thermacore thermal vacuum chamber under hot and cold wall operating conditions. The heat load dissipated ranged from 10 to 60 watts. Heat pipe operating temperatures varied from 278 K to 403 K. After testing, the heat pipe was delivered to NASA JSC where future thermal vacuum chamber tests are planned. {copyright} {ital 1996 American Institute of Physics.}

Gernert, N.J.; Sarraf, D.B. [Thermacore, Inc., 780 Eden Road, Lancaster, Pennsylvania 17601 (United States); Guenther, R.J. [Battelle, Pacific Northwest Laboratories, Richland, Washington 99352 (United States); Hurlbert/, K.M. [NASA Johnson Space Center, 2101 NASA Road, 1 Houston, Texas 77058-3696 (United States); EC3

1996-03-01

471

Pipe weld crown removal device  

DOEpatents

This invention is comprised of a device that provides for grinding down the crown of a pipe weld joining aligned pipe sections so that the weld is substantially flush with the pipe sections joined by the weld. The device includes a cage assembly comprising a pair of spaced cage rings adapted to be mounted for rotation on the respective pipe sections on opposite sides of the weld, a plurality of grinding wheels, supported by the cage assembly for grinding down the crown of the weld, and a plurality of support shafts, each extending longitudinally along the joined pipe sections, parallel thereto, for individually mounting respective grinding wheels. Each end of the support shafts is mounted for rotation in a bearing assembly housed within a radially directed opening in a corresponding one of the cage rings so as to provide radial movement of the associated shaft, and thus of the associated grinding wheel, towards and away from the weld. A first drive sprocket provides rotation of the cage assembly around the pipe sections while a second drive unit, driven by a common motor, provides rotation of the grinding wheels.

Sword, C.K.; Sette, P.J.

1991-12-31

472

New Benchmarks of Economic Policy  

Microsoft Academic Search

The scope of economic transformation in Russia is enormous, and it is not possible to solve all of the accumulated problems in this area in a timely or concrete fashion. There is nothing surprising in the fact that the turnaround of economic policy in the direction of economic growth will seem premature to some. The unfavorable foreign as well as

E. Stroev

1998-01-01

473

Benchmarking the Effective Literacy Rate  

Microsoft Academic Search

By now the importance of literacy in the process of development is widely accepted. However, unlike measuring welfare or inequality, the problem of literacy measurement remains largely unexamined. Alternatives to the standard literacy rate, R, equal to the number of literate adults as a percentage of the adult population, are not well known, but this measure has its deficiencies. In

Travis Lee

2007-01-01

474

Strong quantitative benchmarking of quantum optical devices  

SciTech Connect

Quantum communication devices, such as quantum repeaters, quantum memories, or quantum channels, are unavoidably exposed to imperfections. However, the presence of imperfections can be tolerated, as long as we can verify that such devices retain their quantum advantages. Benchmarks based on witnessing entanglement have proven useful for verifying the true quantum nature of these devices. The next challenge is to characterize how strongly a device is within the quantum domain. We present a method, based on entanglement measures and rigorous state truncation, which allows us to characterize the degree of quantumness of optical devices. This method serves as a quantitative extension to a large class of previously known quantum benchmarks, requiring no additional information beyond what is already used for the nonquantitative benchmarks.

Killoran, N.; Luetkenhaus, N. [Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo, N2L 3G1 (Canada)

2011-05-15

475

Benchmark solutions for MHD solver development  

NASA Astrophysics Data System (ADS)

A benchmark solution is of great importance in validating algorithms and codes for magnetohydrodynamic (MHD) flows. Hunt and Shercliff's solutions are usually employed as benchmarks for MHD flows in a duct with insulated walls or with thin conductive walls, in which wall effects on MHD are represented by the wall conductance ratio. With wall thickness resolved, it is stressed that the solution of Sloan and Smith's and the solution of Butler's can be used to check the error of the thin wall approximation condition used for Hunt's solutions. It is noted that Tao and Ni's solutions can be used as a benchmark for MHD flows in a duct with wall symmetrical or unsymmetrical, thick or thin. When the walls are symmetrical, Tao and Ni's solutions are reduced to Sloan and Smith's solution and Butler's solution, respectively.

Tao, Zhen; Ni, MingJiu

2013-02-01

476

Strong quantitative benchmarking of quantum optical devices  

NASA Astrophysics Data System (ADS)

Quantum communication devices, such as quantum repeaters, quantum memories, or quantum channels, are unavoidably exposed to imperfections. However, the presence of imperfections can be tolerated, as long as we can verify that such devices retain their quantum advantages. Benchmarks based on witnessing entanglement have proven useful for verifying the true quantum nature of these devices. The next challenge is to characterize how strongly a device is within the quantum domain. We present a method, based on entanglement measures and rigorous state truncation, which allows us to characterize the degree of quantumness of optical devices. This method serves as a quantitative extension to a large class of previously known quantum benchmarks, requiring no additional information beyond what is already used for the nonquantitative benchmarks.

Killoran, N.; Lütkenhaus, N.

2011-05-01

477

Nonparametric bayesian methods for benchmark dose estimation.  

PubMed

The article proposes and investigates the performance of two Bayesian nonparametric estimation procedures in the context of benchmark dose estimation in toxicological animal experiments. The methodology is illustrated using several existing animal dose-response data sets and is compared with traditional parametric methods available in standard benchmark dose estimation software (BMDS), as well as with a published model-averaging approach and a frequentist nonparametric approach. These comparisons together with simulation studies suggest that the nonparametric methods provide a lot of flexibility in terms of model fit and can be a very useful tool in benchmark dose estimation studies, especially when standard parametric models fail to fit to the data adequately. PMID:23339666

Guha, Nilabja; Roy, Anindya; Kopylev, Leonid; Fox, John; Spassova, Maria; White, Paul

2013-01-22

478

Shielding Integral Benchmark Archive and Database (SINBAD)  

SciTech Connect

The Shielding Integral Benchmark Archive and Database (SINBAD) collection of benchmarks was initiated in the early 1990 s. 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 computational models with the goal of preserving institutional knowledge and expertise that need to be handed down to future scientists. SINBAD is also a learning tool for university students and scientists who need to design experiments or gain expertise in modeling and simulation. The SINBAD database is currently divided into three categories fission, fusion, and accelerator benchmarks. Where possible, each experiment is described and analyzed using deterministic or probabilistic (Monte Carlo) radiation transport software.

Kirk, Bernadette Lugue [ORNL; Grove, Robert E [ORNL; Kodeli, I. [International Atomic Energy Agency (IAEA); Sartori, Enrico [ORNL; Gulliford, J. [OECD Nuclear Energy Agency

2011-01-01

479

Benchmarking criticality safety calculations with subcritical experiments  

SciTech Connect

Calculation of the neutron multiplication factor at delayed criticality may be necessary for benchmarking calculations but it may not be sufficient. The use of subcritical experiments to benchmark criticality safety calculations could result in substantial savings in fuel material costs for experiments. In some cases subcritical configurations could be used to benchmark calculations where sufficient fuel to achieve delayed criticality is not available. By performing a variety of measurements with subcritical configurations, much detailed information can be obtained which can be compared directly with calculations. This paper discusses several measurements that can be performed with subcritical assemblies and presents examples that include comparisons between calculation and experiment where possible. Where not, examples from critical experiments have been used but the measurement methods could also be used for subcritical experiments.

Mihalczo, J.T.

1984-06-01

480

On 3D object retrieval benchmarking  

NASA Astrophysics Data System (ADS)

The continuous evolution of 3D computer graphics and the progress of 3D digitization systems resulted in a continuous increase in the available 3D content. The widespread use of 3D objects in diverse domains contributed on forming 3D object retrieval as an active research field. In order to objectively evaluate the performance of retrieval methodologies there is a need for objective benchmarking schemes. In this work, we provide a comprehensive overview of the state-of-the-art evaluation methodologies including not only the performance measures but also the corresponding benchmark datasets. Meaningful benchmark datasets are discussed while a detailed list of publicly available 3D model repositories is given organized in terms of application domains, content magnitude and data types. [Figure not available: see fulltext.

Koutsoudis, Anestis; Pratikakis, Ioannis; Chamzas, Christodoulos

2013-12-01

481

Energy benchmarking of South Australian WWTPs.  

PubMed

Optimising the energy consumption and energy generation of wastewater treatment plants (WWTPs) is a topic with increasing importance for water utilities in times of rising energy costs and pressures to reduce greenhouse gas (GHG) emissions. Assessing the energy efficiency and energy optimisation of a WWTP are difficult tasks as most plants vary greatly in size, process layout and other influencing factors. To overcome these limits it is necessary to compare energy efficiency with a statistically relevant base to identify shortfalls and optimisation potential. Such energy benchmarks have been successfully developed and used in central Europe over the last two decades. This paper demonstrates how the latest available energy benchmarks from Germany have been applied to 24 WWTPs in South Australia. It shows how energy benchmarking can be used to identify shortfalls in current performance, prioritise detailed energy assessments and help inform decisions on capital investment. PMID:23656950

Krampe, J

2013-01-01

482

Benchmarking Image Matching for Surface Description  

NASA Astrophysics Data System (ADS)

Semi Global Matching algorithms have encompassed a renaissance to process stereoscopic data sets for surface reconstructions. This method is capable to provide very dense point clouds with sampling distances close to the Ground Sampling Resolution (GSD) of aerial images. EuroSDR, the pan-European organization of Spatial Data Research has initiated a benchmark for dense image matching. The expected outcomes of this benchmark are assessments for suitability, quality measures for dense surface reconstructions and run-time aspects. In particular, aerial image blocks of two sites covering two types of landscapes (urban and rural) are analysed. The benchmark' participants provide their results with respect to several criteria. As a follow-up an overall evaluation is given. Finally, point clouds of rural and urban surfaces delivered by very dense image matching algorithms and software packages are presented and results are compared.

Haala, Norbert; Stößel, Wolfgang; Gruber, Michael; Pfeifer, Norbert; Fritsch, Dieter

2013-04-01

483

Experimental observation of nonlinear traveling waves in turbulent pipe flow.  

PubMed

Transition to turbulence in pipe flow is one of the most fundamental and longest-standing problems in fluid dynamics. Stability theory suggests that the flow remains laminar for all flow rates, but in practice pipe flow becomes turbulent even at moderate speeds. This transition drastically affects the transport efficiency of mass, momentum, and heat. On the basis of the recent discovery of unstable traveling waves in computational studies of the Navier-Stokes equations and ideas from dynamical systems theory, a model for the transition process has been suggested. We report experimental observation of these traveling waves in pipe flow, confirming the proposed transition scenario and suggesting that the dynamics associated with these unstable states may indeed capture the nature of fluid turbulence. PMID:15361619

Hof, Björn; van Doorne, Casimir W H; Westerweel, Jerry; Nieuwstadt, Frans T M; Faisst, Holger; Eckhardt, Bruno; Wedin, Hakan; Kerswell, Richard R; Waleffe, Fabian

2004-09-10

484