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''The Incubation Period for Void Swelling and its Dependence on Temperature, Dose Rate, and Dislocation Structure Evolution'' (open access)

''The Incubation Period for Void Swelling and its Dependence on Temperature, Dose Rate, and Dislocation Structure Evolution''

Void swelling in structural materials used for nuclear reactors is characterized by an incubation period whose duration largely determines the usefulness of the material for core components. Significant evolution of the dislocation and void microstructures that control radiation-induced swelling can occur during this period. Thus, a theory of incubation must treat time-dependent void nucleation in combination with dislocation evolution, in which the sink strengths of voids and dislocations change in concert. We present theoretical results for void nucleation and growth including the time-dependent, self-consistent coupling of point defect concentrations to the evolution of both void populations and dislocation density. Simulations show that the incubation radiation dose is a strong function of the starting dislocation density and of the dislocation bias factors for vacancy and interstitial absorption. Irradiation dose rate and temperature also affect the duration of incubation. The results are in general agreement with experiment for high purity metals.
Date: June 13, 2002
Creator: Surh, M. P.; Sturgeon, J. B. & Wolfer, W. G.
System: The UNT Digital Library
New genome-wide methods bring more power to yeast as a modelorganism (open access)

New genome-wide methods bring more power to yeast as a modelorganism

A collection of 6,000 mutant yeast strains spanning nearlyevery gene offers new promise for identifying human genes involved incellular responses to drugs, radiation and other treatments.
Date: June 13, 2002
Creator: Game, John C.
System: The UNT Digital Library
Cosmic shear with next generation redshift surveys as a cosmological probe (open access)

Cosmic shear with next generation redshift surveys as a cosmological probe

None
Date: December 13, 2002
Creator: Linder, Eric V.
System: The UNT Digital Library
Kaon Production and Kaon to Pion Ratio in Au+Au Collisions at {radical}(s{sub NN})=130 GeV (open access)

Kaon Production and Kaon to Pion Ratio in Au+Au Collisions at {radical}(s{sub NN})=130 GeV

Mid-rapidity transverse mass spectra and multiplicity densities of charged and neutral kaons are reported for Au+Au collisions at {radical}s{sub NN}=130 GeV at RHIC. The spectra are exponential in transverse mass, with an inverse slope of about 280 MeV in central collisions. The multiplicity densities for these particles scale with the negative hadron pseudo-rapidity density. The charged kaon to pion ratios are K{sup +}/{pi}{sup -} = 0.161 {+-} 0.002(stat) {+-} 0.024(syst) and K{sup -}/{pi}{sup -} = 0.146 {+-} 0.002(stat) {+-} 0.022(syst) for the most central collisions. The K{sup +}/{pi}{sup -} ratio is lower than the same ratio observed at the SPS while the K{sup -}/{pi}{sup -} is higher than the SPS result. Both ratios are enhanced by about 50% relative to p+p and {bar p}+p collision data at similar energies.
Date: June 13, 2002
Creator: Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B. D.; Anderson, M. et al.
System: The UNT Digital Library
Resolved magic-angle spinning of anisotropic samples in inhomogeneous fields (open access)

Resolved magic-angle spinning of anisotropic samples in inhomogeneous fields

None
Date: February 13, 2002
Creator: Meriles, Carlos A.; Sakellariou, Dimitris & Pines, Alexander
System: The UNT Digital Library
Mechanisms of photo double ionization of helium by 530 eV photons (open access)

Mechanisms of photo double ionization of helium by 530 eV photons

None
Date: March 13, 2002
Creator: Knapp, A.; Kheifets, A.; Bray, I.; Weber, Th.; Landers, A. L.; Schossler, S. et al.
System: The UNT Digital Library
STATUS OF THE MINOS EXPERIMENT. (open access)

STATUS OF THE MINOS EXPERIMENT.

The author presents the status of the long baseline neutrino oscillation experiment MINOS at Fermi National Accelerator Laboratory (Fermilab). He also summarizes the status of the detector and beam construction, the expected event rates and sensitivity to physics. He also comments on possible future plans to improve the performance of the experiment.
Date: September 13, 2002
Creator: DIWAN,M.
System: The UNT Digital Library
Double K-vacancy production by x-ray photoionization. (open access)

Double K-vacancy production by x-ray photoionization.

We have studied double K-shell photoionization of Ne and Mo (Z = 10 and 42) at the Advanced Photon Source. Double K-vacancy production in Ne was observed by recording the KK-KLL Auger hypersatellite spectrum. Comparison is made with calculations using the multiconfiguration Dirac-Fock method. For Mo, double K-vacancy production was observed by recording the K{alpha}, {beta} fluorescence hypersatellite and satellite x rays in coincidence. From the intensities of the Auger or x-ray hypersatellites relative to diagram lines, the probabilities for double K-vacancy production relative to single K-vacancies were determined. These results, along with reported measurements on other atoms, are compared with Z-scaling calculations of the high-energy limits of the double-to-single K-shell photoionization ratio.
Date: August 13, 2002
Creator: Southworth, S. H.; Dunford, R. W.; Kanter, E. P.; Krassig, B.; Young, L.; Armen, G. B. et al.
System: The UNT Digital Library
Correlations between D and Dbar mesons in high energy photoproduction (open access)

Correlations between D and Dbar mesons in high energy photoproduction

Over 7000 events containing a fully reconstructed D{bar D} pair have been extracted from data recorded by the FOCUS photoproduction experiment at Fermilab. Preliminary results from a study of correlations between D and {bar D} mesons are presented. Correlations are used to study perturbative QCD predictions and investigate non-perturbative effects. We also present a preliminary result on the production of {psi}(3770).
Date: November 13, 2002
Creator: Gottschalk, Erik E
System: The UNT Digital Library
The MESERAN Method: Rapid Quantification of Non-Volatile Organic Residue (NVOR) (open access)

The MESERAN Method: Rapid Quantification of Non-Volatile Organic Residue (NVOR)

The precision analytical technique known as MESERAN Analysis permits quantitative measurement of the level of preexisting nonvolatile organic residue (NVOR) on a substrate from <1 nanogram (ng)/cm{sup 2} to > 100 micrograms ({micro}g)/cm{sup 2} in 2 minutes. MESERAN Analysis is also applicable to determining NVOR in solvents and solvent extracts. The MESERAN method is able to quantify organic contamination levels down to and below 1 ng by depositing as little as 10 microliters ({micro}L) of solvent containing a known amount of contamination on a clean substrate, allowing it to evaporate, and measuring the evaporated residue. The method will be described in detail and NVOR measurements determined from MESERAN data will be presented.
Date: June 13, 2002
Creator: Benkovich, M.G.
System: The UNT Digital Library
Dynamic information architecture system (DIAS) : multiple model simulation management. (open access)

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

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 …
Date: May 13, 2002
Creator: Simunich, K. L.; Sydelko, P.; Dolph, J. & Christiansen, J.
System: The UNT Digital Library
Determination and Correction of the Linear Lattice of the APS Storage Ring. (open access)

Determination and Correction of the Linear Lattice of the APS Storage Ring.

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.
System: The UNT Digital Library
Evaluation of a CIDI pre-transmission parallel hybrid drivetrain with CVT. (open access)

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

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.
System: The UNT Digital Library
Source Release Modeling for the Idaho National Engineering and Environmental Laboratory's Subsurface Disposal Area (open access)

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

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.
System: The UNT Digital Library
SO(10) GUT models and their present success in explaining mass and mixing data (open access)

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

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.
System: The UNT Digital Library
Progress in the fabrication of high aspect ratio zone plates by soft x-ray lithography. (open access)

Progress in the fabrication of high aspect ratio zone plates by soft x-ray lithography.

Soft x-ray lithography technology has been applied to fabrication of phase shifting Fresnel Zone Plate (FZP's) for hard x-rays. Effects of the exposure conditions, developing system, and electroplating process parameters on line width and aspect ratio have been analyzed. The process has been optimized and an aspect ratio of 11 has been achieved for 110 nm outermost zone width. SEM and AFM have been used for preliminary metrology of the FZPs. The FZP optical performance was characterized at 8 keV photon energy at the 2-ID-D beam line at the Advanced Photon Source. Focusing efficiencies of 23% for FZPs apertures to 100 microns and 18% for 150-micron-diameter apertures have been obtained. The parameters of the fabricated FZP are in good agreement with the predicted values.
Date: August 13, 2002
Creator: Divan, R.; Mancini, D. C.; Moldovan, N. A.; Lai, B.; Assoufid, L.; Leondard, Q. et al.
System: The UNT Digital Library
Determination of free hole concentration in ferromagnetic Ga(1-x)MnxAs using electrochemical capacitance-voltage profiling (open access)

Determination of free hole concentration in ferromagnetic Ga(1-x)MnxAs using electrochemical capacitance-voltage profiling

None
Date: March 13, 2002
Creator: Yu, K.M.; Walukiewicz, W.; Wojtowicz, T.; Lim, W.L.; Liu, X.; Sasaki, Y. et al.
System: The UNT Digital Library
Top quark physics with CDF (open access)

Top quark physics with CDF

In this contributions to the proceedings of the HCP conference I will give a brief overview on the CDF upgrade for Run II relevant to top quark physics analyses. I will discuss the CDF top physics program, with particular emphasis to the search for single top quark production. This includes a review of single top quark analyses in Run I.
Date: December 13, 2002
Creator: Wagner, W.
System: The UNT Digital Library
HIGH PERPENDICULAR CHARGED PARTICLES AZIMUTHAL CORRELATION IN PHENIX. (open access)

HIGH PERPENDICULAR CHARGED PARTICLES AZIMUTHAL CORRELATION IN PHENIX.

A two-particle azimuthal correlation analysis of the PHENIX data taken at {radical}s{sub NN} = 130 GeV/c is discussed. A comparison of the magnitude of v{sub 2}(p{perpendicular}) extracted from the correlation analysis with those obtained from a reaction plane analysis by the STAR collaboration, indicate surprisingly small non-flow contributions. A similar comparison obtained from the CERES experiment at {radical}s{sub NN} = 17 GeV/c shows stronger non-flow contributions for a similar p{perpendicular}-range which can be attributed to the presence of mini-jets. It is argued that for the p{perpendicular}-range below 2-3 GeV/c the RHIC results may be indicative of a novel particle production mechanism related to low-x gluon saturation.
Date: January 13, 2002
Creator: RAK,J. FOR THE PHENIX COLLABORATION
System: The UNT Digital Library
Migrating birds : assessment of impact on 915-MHz radar wind profiler performance at the Atmospheric Radiation Measurement Program's southern great plains. (open access)

Migrating birds : assessment of impact on 915-MHz radar wind profiler performance at the Atmospheric Radiation Measurement Program's southern great plains.

The U. S. Department of Energy's Atmospheric Radiation Measurement Program is running a small network of 915-MHz radar wind profilers (RWPs) at its Southern Great Plains Cloud and Radiation Testbed site in northern Oklahoma and southern Kansas. Seasonal migration of passerines may cause significant interference with the operation of 915-MHz RWPs. The extent of this ''bird jamming'' depends on the radar's parameters, the place of deployment, the season, and the time of day. This poster presents a new diagnostic method for detecting possible bird contamination in RWP data, along with an evaluation of the method using a three-year data set for two RWPs.
Date: March 13, 2002
Creator: Pekour, M. S.
System: The UNT Digital Library
Guest editorial, special issue on vacuum discharge plasmas (open access)

Guest editorial, special issue on vacuum discharge plasmas

None
Date: June 13, 2002
Creator: Wang, Jimei; Anders, Andre & Boxman, R.L.
System: The UNT Digital Library
Transition to a nuclear/hydrogen energy system. (open access)

Transition to a nuclear/hydrogen energy system.

The paper explores the motivation for the transition to a nuclear/hydrogen system. For such a transition to be successful the technologies employed must be able to generate enough hydrogen to displace a significant fraction of the petroleum fuels used in the transportation and process heat sectors. This hydrogen must be generated in a manner that is compatible with the environment and independent of foreign fuels. Nuclear energy, along with contributions from wind, solar, and geothermal resources meet the criteria of environmental compatibility and resource independence. However, nuclear energy is the only one of these sources that has a high enough energy density to generate copious quantities of hydrogen. The status of the relevant nuclear and hydrogen technologies are discussed and how they are coupled to bring about a transition to a nuclear/hydrogen system. Should the world adopt such a system then the growth rate of nuclear energy would greatly accelerate. With an accelerated growth for nuclear energy the uranium resources would be depleted in a few decades with the once through fuel cycle currently in use. It is pointed out that deployment of fast breeder reactors would become important in the nearer term.
Date: August 13, 2002
Creator: Walters, L.; Wade, D. & Lewis, D.
System: The UNT Digital Library
A preliminary comparison of beam instabilities among ESRF, APS, and spring-8 x-ray storage ring light sources. (open access)

A preliminary comparison of beam instabilities among ESRF, APS, and spring-8 x-ray storage ring light sources.

A collaboration has been established among the three highest energy storage ring synchrotron light sources: European Synchrotron Radiation Facility (ESRF) (6 GeV), Advanced Photon Source (APS) (7 GeV), and Super Photon Ring (SPring-8) (8 GeV). The goal is to enhance understanding of impedance and beam instability characteristics for present performance and future machine development. In this paper, we compare the beam instability characteristics of the three rings and present a preliminary discussion of the similarities and differences. Topics for future, in-depth study, such as comparing the effect on the beam of in-vacuum insertion devices (IDs) and small-gap chambers, will be described.
Date: June 13, 2002
Creator: Harkay, K.; Nagaoka, R.; Revol, J.-L. & Nakamura, T.
System: The UNT Digital Library
An evaluation of a user-level data transfer mechanism for high-performance networks. (open access)

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

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.
System: The UNT Digital Library