125 Matching Results

Search Results

Advanced search parameters have been applied.

On line sensing of weld penetration using infrared thermography

Description: The objective of this research is to apply new sensing techniques, artificial intelligence, and robotics to improve the welding process through control of penetration depth and width parameters. By producing a constant depth and width of penetration through on line control, the quality and strength of welds may be improved to a new level of reliability previously unobtainable. Experimental data presented in this paper indicate that depth and width of penetration can be monitored by infrared thermography and hence controlled dynamically during the weld process. Infrared thermography is used to monitor surface temperature distributions in the vicinity of the molten metal pool. Characteristics of temperature distributions perpendicular to the direction of arc travel are analyzed and correlated with weld bead width and depth as measured by destructive examination after the weld production. The results show that there is a linear relationship between peak weld plate surface temperature and depth of penetration. Additionally, surface puddle width is found to be directly correlated to measured distance separating solidus temperatures of the molten metal as measured by infrared thermography.
Date: January 1, 1986
Creator: Wang, Y. & Chin, B.A.
Partner: UNT Libraries Government Documents Department

Alternate modal combination methods in response spectrum analysis

Description: In piping analyses using the response spectrum method Square Root of the Sum of the Squares (SRSS) with clustering between closely spaced modes is the combination procedure most commonly used to combine between the modal response components. This procedure is simple to apply and normally yields conservative estimates of the time history results. The purpose of this study is to investigate alternate methods to combine between the modal response components. These methods are mathematically based to properly account for the combination between rigid and flexible modal responses as well as closely spaced modes. The methods are those advanced by Gupta, Hadjian and Lindley-Yow to address rigid response modes and the Double Sum Combination (DSC) method and the Complete Quadratic Combination (CQC) method to account for closely spaced modes. A direct comparison between these methods as well as the SRSS procedure is made by using them to predict the response of six piping systems. For two piping systems thirty-three earthquake records were considered to account for the impact of variations in the characteristics of the excitation. The results provided by each method are compared to the corresponding time history estimates of results as well as to each other. The degree of conservatism associated with each method is characterized. 7 refs., 4 figs., 2 tabs.
Date: January 1, 1989
Creator: Wang, Y.K. & Bezler, P.
Partner: UNT Libraries Government Documents Department

Evaluation of Potential Impacts of Microbial Activity on Drift Chemistry

Description: ''Evaluation of Potential Impacts of Microbial Activity on Drift Chemistry'' focuses on the potential for microbial communities that could be active in repository emplacement drifts to influence the in-drift bulk chemical environment. This report feeds analyses to support the inclusion or exclusion of features, events, and processes (FEPs) in the total system performance assessment (TSPA) for the license application (LA), but this work is not expected to generate direct feeds to the TSPA-LA. The purpose was specified by, and the evaluation was performed and is documented in accordance with, ''Technical Work Plan For: Near-Field Environment and Transport In-Drift Geochemistry Analyses'' (BSC 2004 [DIRS 172402], Section 2.1). This report addresses all of the FEPs assigned by the technical work plan (TWP), including the development of exclusion arguments for FEPs that are not carried forward to the TSPA-LA. Except for an editorial correction noted in Section 6.2, there were no other deviations from the TWP. This report documents the completion of all assigned tasks, as follows (BSC 2004 DIRS 172402, Section 1.2.1): (1) Perform analyses to evaluate the potential for microbial activity in the waste emplacement drift under the constraints of anticipated physical and chemical conditions. (2) Evaluate uncertainties associated with these analyses. (3) Determine whether the potential for microbes warrants a feed to TSPA-LA to account for predicted effects on repository performance. (4) Provide information to address the ''Yucca Mountain Review Plan, Final Report'' (NUREG-1804) (NRC 2003 [DIRS 163274]) and Key Technical Issues and agreements, as appropriate. (5) Develop information for inclusion or exclusion of FEPs.
Date: November 18, 2004
Creator: Wang, Y.
Partner: UNT Libraries Government Documents Department

Tuning the rf cavity by using a detuning loop

Description: The tuning of the rf cavity with a coupling loop connected to a variable capacitor or an open or shorted coaxial line is described. Two kinds of equivalent circuits are described and some of the calculations of ..delta..f and Q vs capacitance curves are given. At 52 MHz the maximum practical tuning range is about 100 KHz, if the parameters of tuning circuit are chosen properly so that the Q of the accelerating cavity does not decrease too much.
Date: September 1, 1985
Creator: Wang, Y.M.; Keane, J. & Batchelor, K.
Partner: UNT Libraries Government Documents Department

HDR URL confirmatory evaluations

Description: One phase of the seismic studies conducted with the decommissioned Heissdampfreaktor in Kahl, West Germany was the prediction of the response of the Recirculation Loop piping (URL) to the 5 Kg blast loading. As a follow-on study to the US effort in this area, BNL performed linear analyses of the URL piping to corroborate the linear analyses performed by an alternate NRC contractor and to verify those analyses considering distinct, independent support excitations. In this study the computer models and processed input data developed by the alternate contractor were used. The BNL effort was initiated in FY 1982 under the Mechanical Piping Benchmark Project. Specifically response predictions were made for the HDR URL system subjected to the 5 Kg blast loading considering uniform support motion with elastic supports and independent support motion with elastic supports. For the evaluations the independently developed BNL finite element piping analysis code, PSAFE2, was used. The paper includes a description of the computer model and comparisons between measured and predicted acceleration time history records for selected points in the system. Predicted results considering both uniform support excitation and independent support excitation are provided.
Date: January 1, 1983
Creator: Bezler, P.; Subudhi, M. & Wang, Y.K.
Partner: UNT Libraries Government Documents Department

Nonlinear failure analysis of a reinforced concrete containment under internal pressure

Description: A detailed nonlinear finite element model is used to investigate the failure response of the Indian Point containment building under severe accident pressures. Refined material models are used to describe the complex stress-strain behavior of the liner and rebar steels, the plain concrete and the reinforced concrete. Structural geometry of the containment is idealized by eight layers of axisymmetric finite elements through the wall thickness in order to closely model the actual placement of the rebars. Soil stiffness under the containment base mat is modeled by a series of nonlinear spring elements. Numerical results presented in the paper describe cracking and plastic deformation (in compression) of the concrete, yielding of the liner and rebar steels and eventual loss of the load carrying capacity of the containment. The results are compared with available data from the previous studies for this containment. 8 references, 9 figures.
Date: January 1, 1984
Creator: Sharma, S.; Wang, Y.K. & Reich, M.
Partner: UNT Libraries Government Documents Department

Effect of PVRC damping with independent support motion response spectrum analysis of piping systems

Description: The Technical Committee for Piping Systems of the Pressure Vessel Research Committee (PVRC) has recommended new damping values to be used in the seismic analyses of piping systems in nuclear power plants. To evaluate the effects of coupling these recommendations with the use of independent support motion analyses methods, two sets of seismic analyses have been carried out for several piping systems. One set based on the use of uniform damping as specified in Regulatory Guide 1.61, the other based on the PVRC recommendations. In each set the analyses were performed using independent support motion time history and response spectrum methods as well as the envelope spectrum method. In the independent response spectrum analyses, 14 response estimates were in fact obtained by considering different combination procedures between the support group contributions and all sequences of combinations between support groups, modes and directions. For each analysis set, the response spectrum results were compared with time history estimates of those results. Comparison tables were then prepared depicting the percentage by which the response spectrum estimates exceeded the time history estimates. By comparing the result tables between both analysis sets, the impact of PVRC damping can be observed. Preliminary results show that the degree of exceedance of the response spectrum estimates based on PVRC damping is less than that based on uniform damping for the same piping problem. Expressed differently the results obtained if ISM methods are coupled with PVRC damping are not as conservative as those obtained using uniform damping.
Date: January 1, 1986
Creator: Wang, Y.K.; Bezler, P. & Shteyngart, S.
Partner: UNT Libraries Government Documents Department

Combination of the primary and secondary stress components for piping systems. [PWR; BWR]

Description: The present study considers several typical piping models subjected to distinct support motions. The independent time history analysis yields both primary stresses due to inertia and secondary stresses due to relative support motions. In addition, this analysis predicts the total response due to both effects. These results presumably are the best estimate of the actual response of a piping system subjected to a real earthquake because the analysis involves solving the system equations at every time step and the phasing during the process of solution is not lost. The piping models were then analyzed using the response spectrum method to obtain the maximum primary stresses. The secondary stresses were next calculated by performing a set of static analysis which result in the most unfavorable combination. These two results are combined by both SRSS and absolute sum methods and the results are compared with the time history solutions.
Date: January 1, 1983
Creator: Subudhi, M.; Wang, Y.K. & Bezler, P.
Partner: UNT Libraries Government Documents Department

Comparison study of time history and response spectrum responses for multiply supported piping systems. [PWR; BWR]

Description: In the past decade, several investigators have studied the problem of independent support excitation of a multiply supported piping system to identify the real need for such an analysis. This approach offers an increase in accuracy at a small increase in computational costs. To assess the method, studies based on the response spectrum approach using independent support motions for each group of commonly connected supports were performed. The results obtained from this approach were compared with the conventional envelope spectrum and time history solutions. The present study includes a mathematical formulation of the independent support motion analysis method suitable for implementation into an existing all purpose piping code PSAFE2 and a comparison of the solutions for some typical piping system using both Time History and Response Spectrum Methods. The results obtained from the Response Spectrum Methods represent the upper bound solution at most points in the piping system. Similarly, the Seismic Anchor Movement analysis based on the SRP method over predicts the responses near the support points and under predicts at points away from the supports.
Date: January 1, 1983
Creator: Wang, Y.K.; Subudhi, M. & Bezler, P.
Partner: UNT Libraries Government Documents Department

Tuning of an rf cavity with a loop inside the cavity

Description: Tuning of an rf cavity with a moving loop inside the cavity is described. The formula to calculate the main parameters ..delta..f and Q of the cavity are given. The results of tests are presented. The advantages of this method are analyzed.
Date: February 1, 1987
Creator: Wang, Y.; Keane, J. & Batchelor, K.
Partner: UNT Libraries Government Documents Department

Compositional and Structural Control on Anion Sorption Capability of Layered Double Hydroxides (LDHS)

Description: Layered double hydroxides (LDHs) have shown great promise as anion getters. In this paper, we demonstrate that the sorption capability of a LDH for a specific oxyanion can be greatly increased by appropriately manipulating material composition and structure. A large set of LDH materials have been synthesized with various combinations of metal cations, interlayer anions, and the molar ratios of divalent cation M(II) to trivalent cation M(III). The synthesized materials have then been tested systematically for their sorption capabilities for pertechnetate (TcO{sub 4}{sup -}). It is discovered that for a given interlayer anion (either CO{sub 3}{sup 2-} or NO{sub 3}{sup -}) the Ni-Al LDH with a Ni/Al ratio of 3:1 exhibits the highest sorption capability among all the materials tested. The distribution coefficient (K{sub d}) is determined to be as high as 307 mL/g for Ni{sub 6}Al{sub 2}(0H){sub 16}CO{sub 3}nH{sub 2}O and 1390 mL/g for Ni{sub 6}Al{sub 2}(OH){sub 16}NO{sub 3}nH{sub 2}O at a pH of 8. The sorption of TcO{sub 4}{sup -} on M(II)-M(III)-CO{sub 3} LDHs is dominated by the edge sites of LDH layers and strongly correlated with the basal spacing d{sub 003} of the materials, which increases with the decreasing radii of both divalent and trivalent cations. The sorption reaches its maximum when the layer spacing is just large enough for a pertechnetate anion to fit into a cage space between two neighboring octahedra of metal hydroxides at the edge. Furthermore, the sorption is found to increase with the crystallinity of the materials. For a given combination of metal cations and an interlayer anion, a best crystalline LDH material is obtained generally with a M(II)/M(III) ratio of 3:1. Replacement of interlayer carbonate with readily exchangeable nitrate greatly increases the sorption capability of a LDH material for pertechnetate, due to the enhanced adsorption on edge sites and the possible ...
Date: March 16, 2006
Creator: Wang, Y. & Gao, H.
Partner: UNT Libraries Government Documents Department


Description: For a pulsed LINAC such as the SNS, an adaptive feed-forward algorithm plays an important role in reducing the repetitive disturbance caused by the pulsed operation conditions. In most modern feed-forward control algorithms, accurate real time system identification is required to make the algorithm more effective. In this paper, an efficient wavelet method is applied to the system identification in which the Haar function is used as the base wavelet. The advantage of this method is that the Fourier transform of the Haar function in the time domain is a sine function in the frequency domain. Thus we can directly obtain the system transfer function in the frequency domain from the coefficients of the time domain system response.
Date: June 1, 2001
Creator: WANG, Y.; KWON, S. & AL, ET
Partner: UNT Libraries Government Documents Department

Influence of Dust on High Temperature Desulfurization of Iron Oxide Sorbent

Description: The understanding of influence of deposited dust on desulfurization performance of sorbent is of significance for developing combined processes for simultaneous desulfurization and dust removal in hot gas cleanup. In this paper, the influence of dust from a fluidized-bed coal gasifier on iron oxide desulfurization sorbent made by a kind of waste material containing iron oxide was systemically evaluated at different temperatures (400 C-550 C) and at different quantity of dust (0.5%-5%) in a fixed-bed reactor. The result showed that dust could interact with sorbent and adversely influenced sulfur capacity and sulfidation rate of sorbent. The influence was promoted with increasing sulfidation temperature and quantity of dust. But below 450 C, the interaction could be neglected. Kinetic studies were also conducted using the grain model. Deposition of dust on the surface of the sorbent could cause the deterioration of mass transfer and the decrease of the effective diffusivities.
Date: September 19, 2002
Creator: Zhao, J.; Huang, J.; Wu, J.; Zhang, J. & Wang, Y.
Partner: UNT Libraries Government Documents Department

BNL piping research

Description: Brookhaven National Laboratory (BNL) has assisted in the development of methods to evaluate the analysis methods used by industry to qualify nuclear power piping. Through FY 1985 these efforts were conducted under the Mechanical Piping Benchmarks project while current and future efforts will be performed under the Combination Procedures for piping project. Under these projects BNL has developed analytical benchmark problems for piping systems evaluated using uniform or independent support motion response spectrum methods, investigated the adequacy and limitations of linear piping analysis methods by comparison to test results and evaluated and developed criteria for new and alternate methods of analysis. A summary description of the status of these efforts is provided.
Date: January 1, 1985
Creator: Bezler, P.; Subudhi, M.; Wang, Y.K. & Shteyngart, S.
Partner: UNT Libraries Government Documents Department

Seismic analysis of fuel and target assemblies at a production reactor

Description: This paper describes the unique modeling and analysis considerations used to assess the seismic adequacy of the fuel and target assemblies in a production reactor at Savannah River Site. This confirmatory analysis was necessary to provide assurance that the reactor can operate safely during a seismic event and be brought to a safe shutdown condition. The plant which was originally designed in the 1950's required to be assessed to more current seismic criteria. The design of the reactor internals and the magnitude of the structural responses enabled the use of a linear elastic dynamic analysis. A seismic analysis was performed using a finite element model consisting of the fuel and target assemblies, reactor tank, and a portion of the concrete structure supporting the reactor tank. The effects of submergence of the fuel and target assemblies in the water contained within the reactor tank can have a significant effect on their seismic response. Thus, the model included hydrodynamic fluid coupling effects between the assemblies and the reactor tank. Fluid coupling mass terms were based on formulations for solid bodies immersed in incompressible and frictionless fluids. The potential effects of gap conditions were also assessed in this evaluation. 5 refs., 6 figs., 1 tab.
Date: January 1, 1991
Creator: Braverman, J.I. & Wang, Y.K.
Partner: UNT Libraries Government Documents Department

Simulation of LMFBR excursion models by means of ICECO

Description: Test data from experiments dealing with LMFBR containment studies are compared with containment code solutions. The features of fluid spillage, which is a subject of some concern in experiments, is modeled in the ICECO code and is stressed. Several variations of spillage solution were arrived at gaining more insight to this problem and thus serve in reducing some of the uncertainties connected with fluid spillage. Other features of the analytical models are utilized and described.
Date: January 1, 1977
Creator: Marchertas, A.H.; Wang, Y.C. & Fistedis, S.H.
Partner: UNT Libraries Government Documents Department

Chemical water/rock interaction under reservoir condition

Description: A simple model is proposed for water/rock interaction in rock fractures through which geothermal water flows. Water/rock interaction experiments were carried out at high temperature and pressure (200-350 C, 18 MPa) in order to obtain basic solubility and reaction rate data. Based on the experimental data, changes of idealized fracture apertures with time are calculated numerically. The results of the calculations show that the precipitation from water can lead to plugging of the fractures under certain conditions. Finally, the results are compared with the experimental data.
Date: January 26, 1995
Creator: Watanabe, K.; Tanifuji, K.; Takahashi, H.; Wang, Y.; Yamasaki, N. & Nakatsuka, K.
Partner: UNT Libraries Government Documents Department

An Analytic Study of the Perpendicularly Propagating Electromagnetic Drift Instabilities in the Magnetic Reconnection Experiment

Description: A local linear theory is proposed for a perpendicularly propagating drift instability driven by relative drifts between electrons and ions. The theory takes into account local cross-field current, pressure gradients and modest collisions as in the Magnetic Reconnection Experiment (MRX) [10]. The unstable waves have very small group velocities in the direction of the pressure gradient, but have a large phase velocity near the relative drift velocity between electrons and ions in the direction of cross-field current. By taking into account the electron-ion collisions and applying the theory in the Harris sheet, we establish that this instability could be excited near the center of the Harris sheet and have enough efoldings to grow to large amplitude before it propagates out of the unstable region. Comparing with the other magnetic reconnection related instabilities (LHDI, MTSI et.) studied previously, we believe the instability we find is a favorable candidate to produce anomalous resistivity because of its unique wave characteristics, such as electromagnetic component, large phase velocity, and small group velocity in the cross current layer direction.
Date: December 3, 2008
Creator: Wang, Y.; Kulsrud, R. & Ji, H.
Partner: UNT Libraries Government Documents Department

A novel method to synthesize high purity, nanostructured copper

Description: Nanostructured high purity (99.999%) copper foils, 10 cm in diameter and 22-25 microns thick were produced using nanoscale multilayer technology. The foils were produced using five different layer thicknesses ranging from 1.25 to 43.6 nm (18,000 to 520 layers). This process delivers the ability to produce multiple large-scale samples during a single deposition run with very small residual stresses. Tensile and indentation tests demonstrate that the material produced is a high strength copper ({sigma}{sub y} {approx} 540-690 MPa).
Date: August 30, 2005
Creator: Hodge, A M; Wang, Y M & Barbee, T W
Partner: UNT Libraries Government Documents Department

Physics: A New Reactor Physics Analysis Toolkit

Description: In the last year INL has internally pursued the development of a new reactor analysis tool: PHISICS. The software is built in a modular approach to simplify the independent development of modules by different teams and future maintenance. Most of the modules at the time of this summary are still under development (time dependent transport driver, depletion, cross section I/O and interpolation, generalized perturbation theory), while the transport solver INSTANT (Intelligent Nodal and Semi-structured Treatment for Advanced Neutron Transport) has already been widely used1, 2, 3, 4. For this reason we will focus mainly on the presentation of the transport solver INSTANT
Date: June 1, 2011
Creator: Rabiti, C.; Wang, Y.; Palmiotti, G.; Hiruta, H.; Cogliati, J. & Alfonsi, A.
Partner: UNT Libraries Government Documents Department