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Zimbabwe: The Transitional Government and Implications for U.S. Policy (open access)

Zimbabwe: The Transitional Government and Implications for U.S. Policy

This report discusses the transitional government in Zimbabwe, economic and humanitarian conditions, and concerns about the country's political future.
Date: July 7, 2010
Creator: Ploch, Lauren
Object Type: Report
System: The UNT Digital Library
Zinc distribution and speciation in Arabidopsis halleri x Arabidops is lyrata progenies presenting various zinc accumulation capacities (open access)

Zinc distribution and speciation in Arabidopsis halleri x Arabidops is lyrata progenies presenting various zinc accumulation capacities

- The purpose of this study was to investigate the relationship between the chemical form and localization of zinc (Zn) in plant leaves and their Zn accumulationcapacity. - An interspecific cross between Arabidopsis halleri sp. halleri and Arabidopsis lyrata sp. petrea segregating for Zn accumulation was used. Zinc (Zn) speciation and Zn distribution in the leaves of the parent plants and of selected F1 and F2 progenies were investigated by spectroscopic and microscopic techniques and chemical analyses. - A correlation was observed between the proportion of Zn being in octahedral coordination complexed to organic acids and free in solution (Zn?OAs + Znaq) and Zn content in the leaves. This pool varied between 40percent and 80percent of total leaf Zn depending on the plant studied. Elemental mapping of the leaves revealed different Zn partitioning between the veins and the leaf tissue. The vein : tissue fluorescence ratio was negatively correlated with Zn accumulation. - The higher proportion of Zn?OAs + Znaq and the depletion of the veins in the stronger accumulators are attributed to a higher xylem unloading and vacuolar sequestration in the leaf cells. Elemental distributions in the trichomes were also investigated, and results support the role of carboxyl and⁄ …
Date: April 8, 2010
Creator: Sarret, Geraldine; Willems, Glenda; Isaure, Marie-Pierre; Marcus, Matthew A.; Fakra, Sirine C.; Frerot, Helene et al.
Object Type: Article
System: The UNT Digital Library
ZINC MITIGATION INTERIM REPORT - THERMODYNAMIC STUDY (open access)

ZINC MITIGATION INTERIM REPORT - THERMODYNAMIC STUDY

An experimental program was initiated in order to develop and validate conditions that will effectively trap Zn vapors that are released during extraction. The proposed work is broken down into three tasks. The first task is to determine the effectiveness of various pore sizes of filter elements. The second task is to determine the effect of filter temperature on zinc vapor deposition. The final task is to determine whether the zinc vapors can be chemically bound. The approach for chemically binding the zinc vapors has two subtasks, the first is a review of literature and thermodynamic calculations and the second is an experimental approach using the best candidates. This report details the results of the thermodynamic calculations to determine feasibility of chemically binding the zinc vapors within the furnace module, specifically the lithium trap (1). A review of phase diagrams, literature, and thermodynamic calculations was conducted to determine if there are suitable materials to capture zinc vapor within the lithium trap of the extraction basket. While numerous elements exist that form compounds with zinc, many of these also form compounds with hydrogen or the water that is present in the TPBARs. This relatively comprehensive review of available data indicates that …
Date: December 17, 2010
Creator: Korinko, P.
Object Type: Report
System: The UNT Digital Library
Zinc Transporter YiiP Escherichia coli (open access)

Zinc Transporter YiiP Escherichia coli

None
Date: March 26, 2010
Creator: Fu, D.
Object Type: Book
System: The UNT Digital Library
ZPR-3 Assembly 11 : A cylindrical sssembly of highly enriched uranium and depleted uranium with an average {sup 235}U enrichment of 12 atom % and a depleted uranium reflector. (open access)

ZPR-3 Assembly 11 : A cylindrical sssembly of highly enriched uranium and depleted uranium with an average {sup 235}U enrichment of 12 atom % and a depleted uranium reflector.

Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more …
Date: September 30, 2010
Creator: Lell, R. M.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Security, National & Engineering, Inst. of Physics and Power
Object Type: Report
System: The UNT Digital Library
ZPR-3 Assembly 12 : A Cylindrical Assembly of Highly Enriched Uranium, Depleted Uranium and Graphite With an Average {Sup 235}U Enrichment of 21 Atom %. (open access)

ZPR-3 Assembly 12 : A Cylindrical Assembly of Highly Enriched Uranium, Depleted Uranium and Graphite With an Average {Sup 235}U Enrichment of 21 Atom %.

Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more …
Date: September 30, 2010
Creator: Lell, R. M.; McKnight, R. D.; Perel, R. L.; Wagschal, J. J.; Division, Nuclear Engineering & Physics, Racah Inst. of
Object Type: Report
System: The UNT Digital Library
ZPR-3 Assembly 6f : A Spherical Assembly of Highly Enriched Uranium, Depleted Uranium, Aluminum and Steel With an Average {Sup 235}U Enrichment of 47 Atom %. (open access)

ZPR-3 Assembly 6f : A Spherical Assembly of Highly Enriched Uranium, Depleted Uranium, Aluminum and Steel With an Average {Sup 235}U Enrichment of 47 Atom %.

Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more …
Date: September 30, 2010
Creator: Lell, R. M.; McKnight, R. D; Schaefer, R. W. & Division, Nuclear Engineering
Object Type: Report
System: The UNT Digital Library

Zuberbueler Bend Northwest Quadrangle

Satellite image topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24,000
Date: 2010
Creator: Geological Survey (U.S.)
Object Type: Map
System: The Portal to Texas History

Zuberbueler Bend Quadrangle

Satellite image topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24,000
Date: 2010
Creator: Geological Survey (U.S.)
Object Type: Map
System: The Portal to Texas History