Diffusion and Settling in Ap/Bp Stars (open access)

Diffusion and Settling in Ap/Bp Stars

Ap/Bp stars are magnetic chemically peculiar early A and late B type stars of the main sequence. They exhibit peculiar surface abundance anomalies that are thought to be the result of gravitational settling and radiative levitation. The physics of diffusion in these stars are reviewed briefly and some model predictions are discussed. While models reproduce some observations reasonably well, more work is needed before the behavior of diffusing elements in a complex magnetic field is fully understood.
Date: April 9, 2003
Creator: Turcotte, S
Object Type: Article
System: The UNT Digital Library
Triggering and data acquisition: General considerations (open access)

Triggering and data acquisition: General considerations

None
Date: April 9, 2003
Creator: Butler, Joel N.
Object Type: Article
System: The UNT Digital Library
Performance of the CDF miniplug calorimeters (open access)

Performance of the CDF miniplug calorimeters

Two Miniplug calorimeters, designed to measure the energy and lateral position of particles in the forward pseudorapidity region of 3.6 < |{eta}| < 5.1, have been installed as part of the CDF upgraded detector for Run II at the Tevatron. Proton-antiproton beams are colliding at {radical}s = 1.96 TeV. One year after installation, Miniplug detector performance and first results are presented.
Date: April 9, 2003
Creator: Gallinaro, M.
Object Type: Article
System: The UNT Digital Library
Status of MARS Code (open access)

Status of MARS Code

Status and recent developments of the MARS 14 Monte Carlo code system for simulation of hadronic and electromagnetic cascades in shielding, accelerator and detector components in the energy range from a fraction of an electronvolt up to 100 TeV are described. these include physics models both in strong and electromagnetic interaction sectors, variance reduction techniques, residual dose, geometry, tracking, histograming. MAD-MARS Beam Line Build and Graphical-User Interface.
Date: April 9, 2003
Creator: Mokhov, N.V.
Object Type: Article
System: The UNT Digital Library
A 3-Dimensional discrete fracture network generator to examine fracture-matrix interaction using TOUGH2 (open access)

A 3-Dimensional discrete fracture network generator to examine fracture-matrix interaction using TOUGH2

Water fluxes in unsaturated, fractured rock involve the physical processes occurring at fracture-matrix interfaces within fracture networks. Modeling these water fluxes using a discrete fracture network model is a complicated effort. Existing preprocessors for TOUGH2 are not suitable to generate grids for fracture networks with various orientations and inclinations. There are several 3-D discrete-fracture-network simulators for flow and transport, but most of them do not capture fracture-matrix interaction. We have developed a new 3-D discrete-fracture-network mesh generator, FRACMESH, to provide TOUGH2 with information about the fracture network configuration and fracture-matrix interactions. FRACMESH transforms a discrete fracture network into a 3 dimensional uniform mesh, in which fractures are considered as elements with unique rock material properties and connected to surrounding matrix elements. Using FRACMESH, individual fractures may have uniform or random aperture distributions to consider heterogeneity. Fracture element volumes and interfacial areas are calculated from fracture geometry within individual elements. By using FRACMESH and TOUGH2, fractures with various inclinations and orientations, and fracture-matrix interaction, can be incorporated. In this paper, results of flow and transport simulations in a fractured rock block utilizing FRACMESH are presented.
Date: April 9, 2003
Creator: Ito, Kazumasa & Yongkoo, Seol
Object Type: Article
System: The UNT Digital Library
Practical superconductor development for electrical power applications: annual report for FY 2002. (open access)

Practical superconductor development for electrical power applications: annual report for FY 2002.

Most large-scale applications of high-critical-temperature superconductors will require conductors that can carry large currents in the presence of applied magnetic fields. This report describes progress at Argonne National Laboratory (ANL) in the research and development of practical superconducting components and devices using the Y-Ba-Cu-O and Bi-Pb-Sr-Ca-Cu-O systems. Results are presented in the areas of fabrication of second- and first-generation composite conductors, characterization of their structures and superconducting properties, investigation of grain-boundary current transport and factors that influence it, testing and modeling of the components of a superconducting fault current limiter, and the measurement and modeling of a superconductor's response to a transient such as that in a fault current limiter after a fault.
Date: April 9, 2003
Creator: Baurceanu, R.; Cha, Y. S.; Dorris, S. E.; Emerson, J. E.; Erck, R. A.; Fisher, B. L. et al.
Object Type: Report
System: The UNT Digital Library
Random walk through recent CDF QCD results (open access)

Random walk through recent CDF QCD results

We present recent results on jet fragmentation, jet evolution in jet and minimum bias events, and underlying event studies. The results presented in this talk address significant questions relevant to QCD and, in particular, to jet studies. One topic discussed is jet fragmentation and the possibility of describing it down to very small momentum scales in terms of pQCD. Another topic is the studies of underlying event energy originating from fragmentation of partons not associated with the hard scattering.
Date: April 9, 2003
Creator: Mesropian, C.
Object Type: Article
System: The UNT Digital Library
Tough2{_}MP: A parallel version of TOUGH2 (open access)

Tough2{_}MP: A parallel version of TOUGH2

TOUGH2{_}MP is a massively parallel version of TOUGH2. It was developed for running on distributed-memory parallel computers to simulate large simulation problems that may not be solved by the standard, single-CPU TOUGH2 code. The new code implements an efficient massively parallel scheme, while preserving the full capacity and flexibility of the original TOUGH2 code. The new software uses the METIS software package for grid partitioning and AZTEC software package for linear-equation solving. The standard message-passing interface is adopted for communication among processors. Numerical performance of the current version code has been tested on CRAY-T3E and IBM RS/6000 SP platforms. In addition, the parallel code has been successfully applied to real field problems of multi-million-cell simulations for three-dimensional multiphase and multicomponent fluid and heat flow, as well as solute transport. In this paper, we will review the development of the TOUGH2{_}MP, and discuss the basic features, modules, and their applications.
Date: April 9, 2003
Creator: Zhang, Keni; Wu, Yu-Shu; Ding, Chris & Pruess, Karsten
Object Type: Article
System: The UNT Digital Library
Synthesis and Luminescent Properties of GaN and GaN-Mn Blue Nanocrystalline Thin-film Phosphor for FED (open access)

Synthesis and Luminescent Properties of GaN and GaN-Mn Blue Nanocrystalline Thin-film Phosphor for FED

The technologies of fabrication of thin film phosphors based on gallium nitride using rf-magnetron sputtering are developed and structural properties of films are studied. Luminescence and electron spin resonance (ESR) spectra of GaN and GaN-Mn thin films have been studied. The correlation between cathodoluminescence intensity and conductivity of GaN films has been found. The nature of emission centers in GaN and GaN-Mn thin films is discussed as well as mechanism of luminescence in these films is proposed.
Date: April 9, 2003
Creator: Bondar, V. D.; Felter, T. E.; Hunt, C. E.; Kucharsky, I. Yo. & Chakhovskoi, A. G.
Object Type: Article
System: The UNT Digital Library
MARS14 simulation of Fermilab 120-GeV beam dumps (open access)

MARS14 simulation of Fermilab 120-GeV beam dumps

To estimate groundwater activation around the Fermilab Switchyard, Meson Target Train and M03 Meson beam dumps at 120 GeV, express MARS14 [1] simulations have been performed. A proton beam RMS spot size is {sigma}{sub x}={sigma}{sub y}=1 cm in the first two cases, while {sigma}{sub x}={sigma}{sub y}=2 cm for M03. Calculated are star density distributions (above 50 MeV) normalized per one incident proton. The configurations proposed by Chuck Brown have been implemented into the MARS code.
Date: April 9, 2003
Creator: Mokhov, Nikolai V.
Object Type: Report
System: The UNT Digital Library