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Residual Stress Predictions in Polycrystalline Alumina

Description: Microstructure-level residual stresses arise in polycrystalline ceramics during processing as a result of thermal expansion anisotropy and crystallographic disorientation across the grain boundaries. Depending upon the grain size, the magnitude of these stresses can be sufficiently high to cause spontaneous microcracking during the processing of these materials. They are also likely to affect where cracks initiate and propagate under macroscopic loading. The magnitudes of residual stresses in untextured and textured alumina samples were predicted using object oriented finite (OOF) element analysis and experimentally determined grain orientations. The crystallographic orientations were obtained by electron-backscattered diffraction (EBSD). The residual stresses were lower and the stress distributions were narrower in the textured samples compared to those in the untextured samples. Crack initiation and propagation were also simulated using the Griffith fracture criterion. The grain boundary to surface energy ratios required for computations were estimated using AFM groove measurements.
Date: December 13, 1999
Creator: VEDULA,VENKATA R.; GLASS,S. JILL; SAYLOR,DAVID M.; ROHRER,GREGORY S.; CARTER,W. CRAIG & LANGER,STEPHEN A.
Partner: UNT Libraries Government Documents Department

Plasma Fueling, Pumping, and Tritium Handling Considerations for FIRE

Description: Tritium pellet injection will be utilized on the Fusion Ignition Research Experiment (FIRE) for efficient tritium fueling and to optimize the density profile for high fusion power. Conventional pneumatic pellet injectors, coupled with a guidetube system to launch pellets into the plasma from the high, field side, low field side, and vertically, will be provided for fueling along with gas puffing for plasma edge density control. About 0.1 g of tritium must be injected during each 10-s pulse. The tritium and deuterium will be exhausted into the divertor. The double null divertor will have 16 cryogenic pumps located near the divertor chamber to provide the required high pumping speed of 200 torr-L/s.
Date: November 13, 1999
Creator: Fisher, P.W.; Foster, C.A.; Gentile, C.A.; Gouge, M.J. & Nelson, B.E.
Partner: UNT Libraries Government Documents Department

Superconducting nanostructured materials.

Description: Within the last year it has been realized that the remarkable properties of superconducting thin films containing a periodic array of defects (such as sub-micron sized holes) offer a new route for developing a novel superconducting materials based on precise control of microstructure by modern photolithography. A superconductor is a material which, when cooled below a certain temperature, loses all resistance to electricity. This means that superconducting materials can carry large electrical currents without any energy loss--but there are limits to how much current can flow before superconductivity is destroyed. The current at which superconductivity breaks down is called the critical current. The value of the critical current is determined by the balance of Lorentz forces and pinning forces acting on the flux lines in the superconductor. Lorentz forces proportional to the current flow tend to drive the flux lines into motion, which dissipates energy and destroys zero resistance. Pinning forces created by isolated defects in the microstructure oppose flux line motion and increase the critical current. Many kinds of artificial pinning centers have been proposed and developed to increase critical current performance, ranging from dispersal of small non-superconducting second phases to creation of defects by proton, neutron or heavy ion irradiation. In all of these methods, the pinning centers are randomly distributed over the superconducting material, causing them to operate well below their maximum efficiency. We are overcome this drawback by creating pinning centers in aperiodic lattice (see Fig 1) so that each pin site interacts strongly with only one or a few flux lines.
Date: July 13, 1998
Creator: Metlushko, V.
Partner: UNT Libraries Government Documents Department

Meteorological forecasting for emergency preparedness and response at the Kennedy Space Center of Florida

Description: The NORAPS model has been used to simulate the motion of Hurricane Erin over Florida. A triplynested grid was used to capture the meteorological features which span from regional to local scales with the highest resolution nest centered at the Kennedy Space Center area. The simulated storm track agreed remarkably well with the observed path of the hurricane. There was also good qualitative agreement between the computed surface precipitation pattern and observations based on radar signatures. Although the validity of the Kuo- type cumulus parameterization scheme used in the model was marginal and even questionable on the finest resolution (4 km) nest, the simulated results were nevertheless qualitatively reasonable. The results generated by NORAPS from the simulation of such a numerical challenging meteorological event were very encouraging. Our next step is to use the meteorological information from the model to provide wind fields for dispersion model simulations of potential atmospheric releases.
Date: October 13, 1995
Creator: Lee, R.L.; Albritton, J.R.; Ermak, D.L.; Hodur, R. & Liou, C.S.
Partner: UNT Libraries Government Documents Department

FENIX experimental results of large-scale CICC made of bronze-processed Nb{sub 3}Sn strands

Description: The Fusion ENgineering International eXperiments (FENIX) Test Facility recently has successfully complete the testing of a pair of Nb{sub 3}rSn cable-in-conduit conductors developed by the Japan Atomic Energy Research Institute. These conductors, made of bronze-processed strands, were designed to operate stably with 40-kA transport current at a magnetic field of 13 T. In addition to the measurements of major design parameters such as current-sharing temperature, FENIX provided several experiments specifically designed to provide results urgently needed by magnet designers. Performed experiments include measurements of ramp-rate limit, current-distribution, stability, and joint performance. This paper presents the design and results of these special experiments.
Date: October 13, 1994
Creator: Shen, S.S.; Felker, B.; Moller, J.M.; Parker, J.M.; Isono, T.; Yasukawa, Y. et al.
Partner: UNT Libraries Government Documents Department

Three dimensional high-resolution simulations of richtmyer-meshkov mixing and shock-turbulence interaction

Description: Three-dimensional high-resolution simulations are performed of the Richtmyer- Meshkov (RM) instability for a Mach 6 shock, and of the passage of a second shock from the same side through a developed RM instability. The second shock is found to rapidly smear fine structure and strongly enhance mixing. Studies of the interaction of moderately strong shocks with a pre-existing turbulent field indicate amplification of transverse vorticity and reduction Of stream-wise vorticity, as well as the mechanisms for these changes.
Date: June 13, 1997
Creator: Cohen, R.H.; Dannevik, W.P.; Dinits, A.; Miason, D.; Mirin, A.A.; Portor, D.H. et al.
Partner: UNT Libraries Government Documents Department

Characterization of Hanford K basin spent nuclear fuel and sludge

Description: A characterization plan was prepared to support the Integrated Process Strategy (IPS) for resolution of the safety and environmental concerns associated with the deteriorating Spent Nuclear Fuel (SNF) stored in the Hanford Site K Basins. This plan provides the structure and logic and identifies the information needs to be supported by the characterization activities. The IPS involves removal of the fuel elements from the storage canister and placing them in a container, i.e., Multiple Canister Overpack (MCO) capable of holding multiple tiers of baskets full of fuel. The MCOs will be vacuum dried to remove free water and shipped to the Container Storage Building (CSB) where they will be staged waiting for hot vacuum conditioning. The MCO will be placed in interim storage in the CSB following conditioning and disposition.
Date: March 13, 1996
Creator: Lawrence, L.A.
Partner: UNT Libraries Government Documents Department

QCD: Challenges for the future

Description: Despite many experimental verifications of the correctness of our basic understanding of QCD, there remain numerous open questions in strong interaction physics and we focus on the role of future colliders in addressing these questions. We discuss possible advances in the measurement of {alpha}{sub s}, in the study of parton distribution functions, and in the understanding of low x physics at present colliders and potential new facilities. We also touch briefly on the role of spin physics in advancing our understanding of QCD.
Date: January 13, 1997
Creator: Burrows, P.; Dawson, S.; Orr, L. & Smith, W.H.
Partner: UNT Libraries Government Documents Department

Fabrication and testing of optics for EUV projection lithography

Description: Extreme Ultraviolet Lithography (EUVL) is a leading candidate as a stepper technology for fabricating the ``0.1 {micro}m generation`` of microelectronic circuits. EUVL is an optical printing technique qualitatively similar to Deep UV Lithography (DUVL), except that 11-13nm wavelength light is used instead of 193-248nm. The feasibility of creating 0.l{micro}m features has been well-established using small-field EWL printing tools, and development efforts are currently underway to demonstrate that cost-effective production equipment can be engineered to perform full-width ring-field imaging consistent with high wafer throughput rates. Ensuring that an industrial supplier base will be available for key components and subsystems is crucial to the success of EUVL. In particular, the projection optics are the heart of the EUVL imaging system, yet they have figure and finish specifications that are beyond the state-of-the-art in optics manufacturing. Thus it is important to demonstrate that industry will be able to fabricate and certify these optics commensurate with EUVL requirements. The goal of this paper is to demonstrate that procuring EUVL projection optical substrates is feasible. This conclusion is based on measurements of both commercially-available and developmental substrates.
Date: March 13, 1998
Creator: Taylor, J. S.
Partner: UNT Libraries Government Documents Department

Sampling and analysis of sludge from the Hanford K East basin

Description: Sludge samples from the floor of the Hanford K East Basin fuel storage pool has been retrieved and analyzed. Both chemical and physical properties have been determined. The results are to be used to determine the disposition of the bulk of the sludge and possibly assess the impact of residual sludge on dry storage of the associated intact metallic uranium fuel elements.
Date: March 13, 1996
Creator: Makenas, B. J.
Partner: UNT Libraries Government Documents Department

Adapting SAM for CDF

Description: The CDF and D0 experiments probe the high-energy frontier and as they do so have accumulated hundreds of Terabytes of data on the way to petabytes of data over the next two years. The experiments have made a commitment to use the developing Grid based on the SAM system to handle these data. The D0 SAM has been extended for use in CDF as common patterns of design emerged to meet the similar requirements of these experiments. The process by which the merger was achieved is explained with particular emphasis on lessons learned concerning the database design patterns plus realization of the use cases.
Date: October 13, 2003
Creator: Bonham, D.; Garzoglio, G.; Herber, R.; Kowalkowski, J.; Litvintsev, D.; Lueking, L. et al.
Partner: UNT Libraries Government Documents Department

Summary and highlights of the 14th Topical Conference on Hadron Collider Physics (HCP2002)

Description: First of all, I would like to thank the scientific committee, the conference organizers, the University of Karlsruhe and the Institute for Experimental Nuclear Physics, all of the speakers, and the conference secretariat, for making this an extremely well-organized and uniformly high-quality meeting. I would also like to thank all of the speakers who provided me with material for my talk before and during the conference. There is obviously no point in these proceedings in attempting to repeat all of the material from the individual contributions; by definition, these are all available earlier in this volume. In the written version, therefore, I will try to give a high level overview of the current state of hadron collider physics and to highlight the connections between the many presentations at this conference.
Date: November 13, 2002
Creator: Womersley, John
Partner: UNT Libraries Government Documents Department

Dynamic information architecture system (DIAS) : multiple model simulation management.

Description: Dynamic Information Architecture System (DIAS) is a flexible, extensible, object-based framework for developing and maintaining complex multidisciplinary simulations of a wide variety of application contexts. The modeling domain of a specific DIAS-based simulation is determined by (1) software Entity (domain-specific) objects that represent the real-world entities that comprise the problem space (atmosphere, watershed, human), and (2) simulation models and other data processing applications that express the dynamic behaviors of the domain entities. In DIAS, models communicate only with Entity objects, never with each other. Each Entity object has a number of Parameter and Aspect (of behavior) objects associated with it. The Parameter objects contain the state properties of the Entity object. The Aspect objects represent the behaviors of the Entity object and how it interacts with other objects. DIAS extends the ''Object'' paradigm by abstraction of the object's dynamic behaviors, separating the ''WHAT'' from the ''HOW.'' DIAS object class definitions contain an abstract description of the various aspects of the object's behavior (the WHAT), but no implementation details (the HOW). Separate DIAS models/applications carry the implementation of object behaviors (the HOW). Any model deemed appropriate, including existing legacy-type models written in other languages, can drive entity object behavior. The DIAS design promotes plug-and-play of alternative models, with minimal recoding of existing applications. The DIAS Context Builder object builds a constructs or scenario for the simulation, based on developer specification and user inputs. Because DIAS is a discrete event simulation system, there is a Simulation Manager object with which all events are processed. Any class that registers to receive events must implement an event handler (method) to process the event during execution. Event handlers can schedule other events; create or remove Entities from the simulation; execute an Entity's behavior; and, of course, change the state of an Entity. In summary, the ...
Date: May 13, 2002
Creator: Simunich, K. L.; Sydelko, P.; Dolph, J. & Christiansen, J.
Partner: UNT Libraries Government Documents Department

Determination and correction of the linear lattice of the APS storage ring.

Description: We have created precise linear models of the storage ring in terms of {beta}-functions for both low-emittance and high-emittance lattices. Using these models, the {beta}-function beating corrections have been successfully applied. The lifetime was increased by 40% for the low-emittance lattice as a result of the corrections. The models allow the user to apply predictable and precise changes to the existing lattice. For example, after applying the {beta}-function corrections, the {beta}-function changes exactly coincide with the changes predicted by the model. This work would not be possible without the help provided by many APS people. In particular, one of the authors (VS) would like to thank S. Milton for stimulating and supporting the work, and M. Borland for his tremendous support with regard to the storage ring operation and software implementation.
Date: June 13, 2002
Creator: Sajaev, V. & Emery, L.
Partner: UNT Libraries Government Documents Department

Evaluation of a CIDI pre-transmission parallel hybrid drivetrain with CVT.

Description: Argonne National Laboratory (ANL) is the lead laboratory for hardware-in-the-loop (HIL) testing and technology validation for the U.S. Department of Energy's Office of Advanced Automotive Technologies (DOE OAAT). In this role, ANL contributes to DOE OAAT goals by setting technical targets and evaluating new technologies in a vehicle systems context, with a focus on hybrid electric vehicle (HEV) technology. ANL employs a unique integrated process based on powerful simulation tools and experimental facilities to perform system-level tests quickly and cost-effectively. This approach allows ANL researchers to simulate a vehicle system, design an optimal control strategy, and then apply it to the real components and subsystems being evaluated. The objective is to better understand (1) component/subsystem performance and control requirements in a simulated vehicle environment and (2) the effect of control on emissions and efficiency. This process has been applied to the evaluation of a hybrid powertrain consisting of a Compression-Ignition Direct-Injection (CIDI) engine, an electric traction motor, and a Continuously Variable Transmission (CVT). This paper describes the testing methodology, the building of the powertrain, the control strategy used, and the analysis of results.
Date: August 13, 2002
Creator: Pasquier, M.; Duoba, M.; Hardy, K.; Rousseau, A. & Shimcoski, D.
Partner: UNT Libraries Government Documents Department

Remote Inspection of a 46 Year Old Buried High Level Waste Storage Tank

Description: This paper provides a description of the remote ultrasonic examinations of a high level radioactive waste storage tank at the Savannah River Site. The inspections were performed from the contaminated, annular space of the 46 year old, inactive, 1.03 million gallon waste storage tank.
Date: May 13, 2003
Creator: Elder, J.B.
Partner: UNT Libraries Government Documents Department

The scalar {kappa} from D{sup +} {yields} K{sup -} {pi}{sup +}{pi}{sup +}: Further studies

Description: We briefly review the recent results obtained by Fermilab experiment E791 on the Dalitz plot analysis of the decay D{sup +} {yields} K{sup -} {pi}{sup +}{pi}{sup +}, where indication for a light K {pi} scalar resonance, the {kappa}, was found. We also present preliminary studies providing further information on the phase behavior of the scalar components at low mass, supporting the previous indication for the {kappa}.
Date: August 13, 2003
Creator: Gobel, Carla
Partner: UNT Libraries Government Documents Department

An evaluation of a user-level data transfer mechanism for high-performance networks.

Description: In this paper, we describe FOBS: a simple user-level communication protocol designed to take advantage of the available bandwidth in a high-bandwidth, high-delay network environment. We compare the performance of FOBS with that of TCP both with and without the so-called Large Window extensions designed to improve the performance of TCP in this type of network environment. We show that FOBS can obtain on the order of 90% of the available bandwidth across both short- and long-haul high-performance network connections. For the long-haul connection, the bandwidth obtained was 1.8 times higher than that of the optimized TCP algorithm. Also, we demonstrate that the additional traffic placed on the network because of the greedy nature of the algorithm is quite reasonable, representing approximately 3% of the total data transferred.
Date: August 13, 2002
Creator: Dickens, P. M. & Gropp, W.
Partner: UNT Libraries Government Documents Department

SO(10) GUT models and their present success in explaining mass and mixing data

Description: Some features of SO(10) GUT models are reviewed, and a number of such models in the literature are compared. While some have been eliminated by recent neutrino data, others are presently successful in explaining the quark and lepton mass and mixing data. A short description of one very predictive model is given which illustrates some of the features discussed. Future tests of the models are pointed out including one which contrasts sharply with those models based on an L{sub e}-L{sub {mu}}-L{sub {tau}} type symmetry.
Date: December 13, 2002
Creator: Albright, Carl H.
Partner: UNT Libraries Government Documents Department

Source Release Modeling for the Idaho National Engineering and Environmental Laboratory's Subsurface Disposal Area

Description: A source release model was developed to determine the release of contaminants into the shallow subsurface, as part of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) evaluation at the Idaho National Engineering and Environmental Laboratory's (INEEL) Subsurface Disposal Area (SDA). The output of the source release model is used as input to the subsurface transport and biotic uptake models. The model allowed separating the waste into areas that match the actual disposal units. This allows quantitative evaluation of the relative contribution to the total risk and allows evaluation of selective remediation of the disposal units within the SDA.
Date: May 13, 2002
Creator: Becker, B.H.
Partner: UNT Libraries Government Documents Department