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Combining Spatial-Temporal and Phylogenetic Analysis Approaches for Improved Understanding on Global H5N1 Transmission (open access)

Combining Spatial-Temporal and Phylogenetic Analysis Approaches for Improved Understanding on Global H5N1 Transmission

This article reports an interdisciplinary effort that combines the geospatial informatics approach with a bioinformatics approach to form an improved understanding on the transmission mechanisms of H5N1 virus.
Date: October 22, 2010
Creator: Liang, Lu; Xu, Bing; Chen, Yanlei; Liu, Yang; Cao, Wuchun; Fang, Liqun et al.
System: The UNT Digital Library
Enhanced Magnetism of Fe3O4 Nanoparticles with Ga Doping (open access)

Enhanced Magnetism of Fe3O4 Nanoparticles with Ga Doping

Magnetic (Ga{sub x}Fe{sub 1-x}){sub 3}O{sub 4} nanoparticles with 5%-33% gallium doping (x = 0.05-0.33) were measured using x-ray absorption spectroscopy and x-ray magnetic circular dichroism to determine that the Ga dopant is substituting for Fe{sub 3+} as Ga{sub 3+} in the tetrahedral A-site of the spinel structure, resulting in an overall increase in the total moment of the material. Frequency-dependent alternating-current magnetic susceptibility measurements showed these particles to be weakly interacting with a reduction of the cubic anisotropy energy term with Ga concentration. The element-specific dichroism spectra show that the average Fe moment is observed to increase with Ga concentration, a result consistent with the replacement of A-site Fe by Ga.
Date: October 22, 2010
Creator: Pool, V. L.; Klem, M. T.; Chorney, C. L.; Arenholz, E. & Idzerda, Y.U.
System: The UNT Digital Library
New Superheavy Element Isotopes: 242Pu(48Ca,5n)285114 (open access)

New Superheavy Element Isotopes: 242Pu(48Ca,5n)285114

The new, neutron-deficient, superheavy element isotope {sup 285}114 was produced in {sup 48}Ca irradiations of {sup 242}Pu targets at a center-of-target beam energy of 256 MeV (E* = 50 MeV). The {alpha} decay of {sup 285}114 was followed by the sequential {alpha} decay of four daughter nuclides, {sup 281}Cn, {sup 277}Ds, {sup 273}Hs, and {sup 269}Sg. {sup 265}Rf was observed to decay by spontaneous fission. The measured {alpha}-decay Q values were compared with those from a macroscopic-microscopic nuclear mass model to give insight into superheavy element shell effects. The {sup 242}Pu({sup 48}Ca,5n){sup 285}114 cross section was 0.6{sub -0.5}{sup +0.9} pb.
Date: October 22, 2010
Creator: Ellison, Paul A; Gregorich, Kenneth E.; Berryman, Jill S.; Bleuel, Darren L.; Clark, Roderick M.; Dragojevic, Irena et al.
System: The UNT Digital Library
Orbital Moment Determination in (MnxFe1-x)3O4 Nanoparticles (open access)

Orbital Moment Determination in (MnxFe1-x)3O4 Nanoparticles

Nanoparticles of (Mn{sub x}Fe{sub 1-x}){sub 3}O{sub 4} with a concentration ranging from x = 0 to 1 and a crystallite size of 14-15 nm were measured using X-ray absorption spectroscopy and X-ray magnetic circular dichroism to determine the ratio of the orbital moment to the spin moment for Mn and Fe. At low Mn concentrations, the Mn substitutes into the host Fe{sub 3}O{sub 4} spinel structure as Mn{sup 2+} in the tetrahedral A-site. The net Fe moment, as identified by the X-ray dichroism intensity, is found to increase at the lowest Mn concentrations then rapidly decrease until no dichroism is observed at 20% Mn. The average Fe orbit/spin moment ratio is determined to initially be negative and small for pure Fe{sub 3}O{sub 4} nanoparticles and quickly go to 0 by 5%-10% Mn addition. The average Mn moment is anti-aligned to the Fe moment with an orbit/spin moment ratio of 0.12 which gradually decreases with Mn concentration.
Date: October 22, 2010
Creator: Pool, V. L.; Jolley, C.; Douglas, T.; Arenholz, E. & Idzerda, Y. U.
System: The UNT Digital Library
Photodetectors for Scintillator Proportionality Measurement (open access)

Photodetectors for Scintillator Proportionality Measurement

None
Date: October 22, 2010
Creator: Moses, William W.; Choong, W. -S.; Hull, G.; Payne, S.; Cherepy, N. & Valentine, J. D.
System: The UNT Digital Library
Planning Tools for Estimating Radiation Exposure at the National Ignition Facility (open access)

Planning Tools for Estimating Radiation Exposure at the National Ignition Facility

A set of computational tools was developed to help estimate and minimize potential radiation exposure to workers from material activation in the National Ignition Facility (NIF). AAMI (Automated ALARA-MCNP Interface) provides an efficient, automated mechanism to perform the series of calculations required to create dose rate maps for the entire facility with minimal manual user input. NEET (NIF Exposure Estimation Tool) is a web application that combines the information computed by AAMI with a given shot schedule to compute and display the dose rate maps as a function of time. AAMI and NEET are currently used as work planning tools to determine stay-out times for workers following a given shot or set of shots, and to help in estimating integrated doses associated with performing various maintenance activities inside the target bay. Dose rate maps of the target bay were generated following a low-yield 10{sup 16} D-T shot and will be presented in this paper.
Date: October 22, 2010
Creator: Verbeke, J.; Young, M.; Brereton, S.; Dauffy, L.; Hall, J.; Hansen, L. et al.
System: The UNT Digital Library