Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

University of Nevada, Las Vegas

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 2911 - 2940 of 3930

Full-Text Articles in Physical Sciences and Mathematics

Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications, Biswajit Das Jan 2007

Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications, Biswajit Das

Transmutation Sciences Materials (TRP)

Advanced transmutation systems require structural materials that are able to withstand high neutron fluxes, high thermal cycling, and high resistance to chemical corrosion. The current candidate materials for such structures are ferritic and ferritic-martensitic steels due to their strong resistance to swelling, good microstructural stability under irradiation, and the retention of adequate ductility at typical reactor operating temperatures.

In parallel, lead-bismuth eutectic (LBE) has emerged as a potential spallation target material for efficient production of neutrons, as well as a coolant in the accelerator system. While LBE has excellent properties as a nuclear coolant, it is also highly corrosive to …


Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Matrix, Spencer M. Steinberg, Gary Cerefice, David W. Emerson Jan 2007

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Matrix, Spencer M. Steinberg, Gary Cerefice, David W. Emerson

Separations Campaign (TRP)

The stability of the association of iodine with FCC and NOM products were studied. Product distributions for the various matrices under various reaction conditions were examined in order to maximize the binding of iodine. The recovery of the iodine from the sequestration matrices was also examined, along with the conversion of the iodine to matrices more suitable for geological storage and/or use as transmutation targets.

The following are the specific research objectives and goals:

  • Develop bench-scale experimental set-up and procedures for simulating plutonium extraction process (PUREX) head-end vapor phase.
  • Develop experimental procedures for evaluating iodine sequestering methods using bench-scale procedures. …


Development Of Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Yitung Chen, Sean Hsieh Jan 2007

Development Of Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Yitung Chen, Sean Hsieh

Separations Campaign (TRP)

The major objectives will lead to a creation of framework that combines all the strengths of AMUSE’s complicated calculations, well-established commercial system process package and ISOPro’s flexible parameter optimization modules. Development of the process simulation code can be done using the solvent extraction process at Argonne National Laboratory in collaboration with the research team from Mechanical Engineering Department at UNLV.

Research accomplishments:

  • Integrated the ASPEN-Plus process model with the ISOPro system engineering modeling package, developed by the UNLV team.
  • Tested the simplified system process integration using the ISOPro package.
  • Generated complete version of the ISOPro package user manual and tutorial. …


Electrochemical Separation Of Curium And Americium, David W. Hatchett, Kenneth Czerwinski Jan 2007

Electrochemical Separation Of Curium And Americium, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

The objectives of this project are to use electrochemical techniques to develop a thermodynamic understanding of actinide and lanthanide species in RTIL solution, and to use this data to effectively separate species with very similar chemical properties. In consultation with a national laboratory collaborator, electrochemical methods and materials will be evaluated and used to exploit the thermodynamic differences between similar chemical species, enhancing the ability to selectively target and sequester individual species from mixtures. This project is in its third year and has successfully completed phases 1 and 2. Phase 3 has been partially completed. The tasks have been expanded …


Fundamental Chemistry Of U And Pu In The Tbp-Dodecane-Nitric Acid System, Kenneth Czerwinski Jan 2007

Fundamental Chemistry Of U And Pu In The Tbp-Dodecane-Nitric Acid System, Kenneth Czerwinski

Separations Campaign (TRP)

The research objective is to experimentally evaluate the fundamental speciation of Pu and U in the TBP-dodecane-nitric acid- AHA system and the effect of pertechnetate, specifically:

To determine the influence of nitrate on the speciation of U and Pu in the TBP-dodecane-nitric acid system. The aqueous and organic speciation of U and Pu are examined as a function of the nitric acid concentration, nitrate concentration, actinide ion concentration, temperature, and time.

To determine the speciation of U and Pu with AHA in the presence and absence of TBP-dodecane organic phase. The aqueous and organic speciation of U and Pu are …


F-Element Electrochemistry In Room Temperature Ionic Liquids, David W. Hatchett, Kenneth Czerwinski Jan 2007

F-Element Electrochemistry In Room Temperature Ionic Liquids, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

This proposal focuses on f-element electrochemistry in room temperature ionic liquids (RTILs). The ultimate goal is to fully characterize the oxidation/reduction of elements in RTILs to establish the baseline thermodynamic and kinetic data for these systems. The data will be used to critically evaluate the ability to use electrochemical methods for controlled, potential mediated, separation off-elements by electroplating on electrodes surfaces. Factors that will influence the ability to measure the redox processes in f-elements in RTIL solutions and electroplating on electrode surfaces include the structure, solubility, and stability of the target species in these solutions. These factors will be addressed …


Evaluation Of Fundamental Radionuclide Extraction Data For Urex, Kenneth Czerwinski Jan 2007

Evaluation Of Fundamental Radionuclide Extraction Data For Urex, Kenneth Czerwinski

Separations Campaign (TRP)

The speciation of technetium and actinides in advanced solvent extraction systems is the basis for their manipulation in separations. The ability to understand and predict radionuclide speciation is paramount to successful modeling of proposed separation systems. This project will examine the speciation of radionuclides in different stages of the UREX separation scheme, providing data useful to modeling. The areas to be examined include the speciation of U and Pu with tributylphosphate and the kinetics and thermodynamics of lanthanides and actinides in the TALSPEAK system. The complexation constants of U and Pu with tributylphosphate will be evaluated. In the TALSPEAK system, …


Separation Of Technetium From Uranium And Waste Form Synthesis, Kenneth Czerwinski Jan 2007

Separation Of Technetium From Uranium And Waste Form Synthesis, Kenneth Czerwinski

Waste Forms Campaign (TRP)

In this project, systematic investigations on the Tc-Zr binary metal system will be evaluated for the first time. The synthesis of metallic Tc as well as its alloys with Zr will be evaluated. In order to provide valuable data to AFC R&D, the thermodynamic equilibrium phases, as well as their performance under repository conditions, will be examined.


Evaluation Of Cs/Sr Waste Form For Long Term Storage And Disposal, Gary Cerefice, Longzhou Ma Jan 2007

Evaluation Of Cs/Sr Waste Form For Long Term Storage And Disposal, Gary Cerefice, Longzhou Ma

Waste Forms Campaign (TRP)

The goal of this project is to examine two potential concerns regarding the long-term performance of a proposed cesium/ strontium waste form. To facilitate long-term storage, up to 300 years, the disposal containers will need to be able to survive for the entire storage interval. The first aspect of the project will explore the potential interaction of the aluminosilicate waste form with the storage canister materials to determine if there is any corrosion or chemical interaction concerns for the storage of the materials.

At the end of the storage interval, most of the 137Cs in the waste form will have …


Discover Mojave Outdoor World Activity Unit Curriculum, Daphne Sewing, Jennell M. Miller, Allison Brody Jan 2007

Discover Mojave Outdoor World Activity Unit Curriculum, Daphne Sewing, Jennell M. Miller, Allison Brody

Curriculum materials (DM)

This document provides suggested activity outlines for each recreational unit as well as available resources, pertinent contacts, checklists, and activity assessments. Each unit is correlated with the themes identified by the Southern Nevada Agency Partnership Conservation Education and Interpretation Team.

The Discover Mojave Outdoor World program introduces urban youth, ages 8-12, to outdoor recreation and environmental education. The program promotes the belief that outdoor recreation plays an important and positive role in the health and fitness of America’s youth.

The program is patterned after the national Wonderful Outdoor World (WOW) program. WOW introduces urban youth and families to the outdoors …


Learning Science At The Lake: A Successful Partnership Between Formal And Informal Educators, Public Lands Institute Jan 2007

Learning Science At The Lake: A Successful Partnership Between Formal And Informal Educators, Public Lands Institute

Presentations (DM)

Emphasis on cooperative conservation through:

  • Education
  • Research
  • Community Engagement


Assessing “Discover Mojave”, Year Two: Final Report, Lori Olafson, Gregory Schraw, Michelle L. Weibel Jan 2007

Assessing “Discover Mojave”, Year Two: Final Report, Lori Olafson, Gregory Schraw, Michelle L. Weibel

Reports (DM)

Discover Mojave Outdoor World is a hands-on outdoor recreation program for urban, economically disadvantaged youth. In Year One of the program, knowledge, attitude, and performance assessments were developed to document the effectiveness of program events over the duration of the program. Year One findings revealed that knowledge, attitudes, and performance increased substantially as a result of participating in the outdoor recreation events. The assessment plan was modified in Year Two by creating assessments for teachers and parents, as well as a developing a structured interview protocol. Changes were made to existing assessments and two new assessment tools were implemented. Findings …


Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke Jan 2007

Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke

Civil and Environmental Engineering and Construction Faculty Research

Inversion of shear-wave velocity profiles from phase-velocity measurements of Rayleigh-wave energy for sites containing stiff layers can be erroneous if such layers are not characterized in the starting or reference model. Incorporation of a priori knowledge then is key for converging upon a realistic or meaningful solution. Resolving soil profiles in desert regions where stiff layers cemented with calcium carbonate are intermixed with softer, uncemented media is an application for which locating shallow stiff inclusions has important implications. Identification of the stiff layers is critical for foundation design and cost estimating of excavations. A parameterization that seems adequate for this …


Las Vegas: A Sustainable Urban Environment For Health?, Nancy Menzel Jan 2007

Las Vegas: A Sustainable Urban Environment For Health?, Nancy Menzel

Nevada Journal of Public Health

The rapid growth of Las Vegas has resulted in negative consequences for the health of its residents to a level that threatens the area’s sustainability. This article reviews key indicators of population health in Las Vegas through the framework of the US Centers for Disease Control and Prevention’s Healthy People in Healthy Places and concludes that public health professionals, citizens, businesses, and political leaders must act now to protect and improve population health.


Geostatistical And Stochastic Study Of Radionuclide Transport In The Unsaturated Zone At Yucca Mountain, Feng Pan, Ming Ye, Jianting Zhu Jan 2007

Geostatistical And Stochastic Study Of Radionuclide Transport In The Unsaturated Zone At Yucca Mountain, Feng Pan, Ming Ye, Jianting Zhu

Publications (YM)

Motivation: Why Study of Unsaturated Zone? The unsaturated zone (UZ), where the proposed repository would be located, acts as a critical natural barrier by delaying the arrival of radionuclides at the saturated zone and by reducing radionuclide concentrations in groundwater through dispersion and dilution Quantitative prediction of radionuclide transport in the unsaturated zone becomes critical for performance assessment and design of the proposed repository of the Yucca Mountain Project


Precipitation Monitoring At Yucca Mountain, Klaus J. Stetzenbach, Amanda Brandt Jan 2007

Precipitation Monitoring At Yucca Mountain, Klaus J. Stetzenbach, Amanda Brandt

Publications (YM)

Objectives:

Status of the Task to Date
Network Overview/ Equipment
Data Trends
Uses and Collaborative Projects
Spatial Interpolation of YM Rainfall
Storm Event Analysis
Shallow Groundwater Response to Rainfall
UE29a1 Water Level Response to Barometric Pressure Fluctuation


Yucca Mountain Climate: Past, Present, And Future, Saxon E. Sharpe Jan 2007

Yucca Mountain Climate: Past, Present, And Future, Saxon E. Sharpe

Publications (YM)

Evaluation of modern climate is necessary to relate climatic events to near-surface processes such as infiltration, runoff, and evapotranspiration. Modern climate information also aids in environmental analyses of repository design facilities and atmospheric dispersion models. Evaluation of past climate regimes, particularly temperature and precipitation, is needed to assess the relation of past climate to past hydrologic conditions. Estimates of potential future climate and hydrology are needed to evaluate repository performance.


Yucca Mountain Saturated Zone Carbon-14, James Thomas, David L. Decker, Todd M. Mihevc, Ronald L. Hershey, Gary Patterson, Zell Peterman, Peter Striffler Jan 2007

Yucca Mountain Saturated Zone Carbon-14, James Thomas, David L. Decker, Todd M. Mihevc, Ronald L. Hershey, Gary Patterson, Zell Peterman, Peter Striffler

Publications (YM)

Travel time of groundwater from beneath Yucca Mountain to down gradient areas is important to nuclear waste storage.
For this study, travel times determined by:
1) Dissolved inorganic carbon (DIC) isotopes Geochemical modeling--corrected C-14 ages
2) Dissolved organic carbon (DOC) isotopes DOC ages independent of DIC reactions


Design Concepts And Process Analysis For Transmuter Fuel Manufacturing, Georg F. Mauer Jan 2007

Design Concepts And Process Analysis For Transmuter Fuel Manufacturing, Georg F. Mauer

Fuels Campaign (TRP)

The safe and effective manufacturing of actinide-bearing fuels for any transmutation strategy requires that the entire manufacturing process be contained within a shielded hot cell environment. To ensure that the fabrication process is feasible, the entire process must be designed for remote operation. The equipment must be reliable enough to perform over several decades, and also easy to maintain or repair remotely. The facility must also be designed to facilitate its own decontamination and decommissioning. In addition to these design factors, the potential viability of any fuel fabrication process will also be impacted by a number of variables, such as …


Impact Of The Synthesis Process On Structure Properties For Afci Fuel Candidates, Kenneth Czerwinski Jan 2007

Impact Of The Synthesis Process On Structure Properties For Afci Fuel Candidates, Kenneth Czerwinski

Fuels Campaign (TRP)

Synthesis of actinium mononitrides using carbothermic reduction of the corresponding oxides has a few outstanding issues, including the formation of secondary phases such as oxides and carbides and low densities of the final product. Furthermore the requirement of a high process temperature at 1700°C, for more than 12 hours is also a drawback particularly for Americium-bearing samples. Therefore, it is important to explore the use of other possible routes to synthesize actinide mononitrides.

A low temperature process is used in this research to produce actinide mononitrides using a fluoride route in which the first step is to mix the actinide …


Solution-Based Synthesis Of Nitride Fuels, Tyler A. Sullens, Kenneth Czerwinski Jan 2007

Solution-Based Synthesis Of Nitride Fuels, Tyler A. Sullens, Kenneth Czerwinski

Fuels Campaign (TRP)

The preliminary studies into the synthesis of actinide nitride fuels through a low temperature, liquid ammonia based synthesis route have been conducted on the uranium containing system, and there is good indication for the success of synthesizing uranium (III) nitride. The dissolution of iodine in ammonia is a rapid process, resulting in a pale green solution, which does not result in any observable oxidation of iodine. The cannula transfer of dissolved iodine into the reaction vessel containing U metal has been conducted with little to no residual iodine remaining in the original flask. The metal being used for these reactions …


Evaluation Of Fluorapatite As A Waste-Form Material, Dennis W. Lindle, Oliver Hemmers, Dale L. Perry Jan 2007

Evaluation Of Fluorapatite As A Waste-Form Material, Dennis W. Lindle, Oliver Hemmers, Dale L. Perry

Separations Campaign (TRP)

Argonne National Laboratory has proposed a new extraction procedure to handle TRISO-coated fuels, the Fluoride Extraction Process, or FLEX. The FLEX process is designed to separate the uranium in the fuel from the actinides and most fission products by taking advantage of the unique properties of uranium hexafluoride (UF6). In the FLEX process, the used TRISO fuel is reacted with zirconium fluoride salt, forming UF6 and the fluoride salts of the actinides and fission products. At process temperatures, the UF6 volatizes into a gas, and is released from the molten salt mixture. This leaves behind the …


Chemical Analyses In Support Of Yucca Mountain Studies, Harry Reid Center For Environmental Studies, University Of Nevada, Las Vegas Jan 2007

Chemical Analyses In Support Of Yucca Mountain Studies, Harry Reid Center For Environmental Studies, University Of Nevada, Las Vegas

Publications (YM)

Research Objectives: Provide preparation of injectates, sorption studies and analyses for tracer tests Provide REE, trace metals, majors and field measurement data from wells of the Nye County Early Warning Drilling Program (NCEWDP)and Inyo County Other laboratory needs as they arise


Design And Performance Of A Curved-Crystal X-Ray Emission Spectrometer, A. C. Hudson, Wayne C. Stolte, Dennis W. Lindle, Renaud Guillemin Jan 2007

Design And Performance Of A Curved-Crystal X-Ray Emission Spectrometer, A. C. Hudson, Wayne C. Stolte, Dennis W. Lindle, Renaud Guillemin

Chemistry and Biochemistry Faculty Research

A curved-crystal x-ray emission spectrometer has been designed and built to measure 2–5 keV x-ray fluorescence resulting from a core-level excitation of gas phase species. The spectrometer can rotate 180°, allowing detection of emitted x rays with variable polarization angles, and is capable of collecting spectra over a wide energy range (20 eV wide with 0.5 eV resolution at the Cl K edge) simultaneously. In addition, the entire experimental chamber can be rotated about the incident-radiation axis by nearly 360° while maintaining vacuum, permitting measurements of angular distributions of emitted x rays.


Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix, Kenneth Czerwinski Jan 2007

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix, Kenneth Czerwinski

Fuels Campaign (TRP)

This project will examine inert fuels containing ZrO2 and MgO as the inert matrix. Ceramics with this inert matrix, Ce, U and eventually Pu will be synthesized and examined. While the Advanced Fuel Cycle Initiative focus is on inert fuels with Pu as the fissile component, this task will perform initial laboratory experiments with Ce and U. The initial work with Ce will be performed early in the project with results used as a basis for U studies. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf. …


Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske Jan 2007

Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske

Fuels Campaign (TRP)

This project focuses on the chemical bonding and interface formation of metal fission products with the coating materials used in tri-isotropic (TRISO) fuel particles for gas-cooled reactors. By combining surface- and bulk-sensitive spectroscopic methods, intermediate chemical phases at the interface, intermixing/ diffusion behavior, and the electronic interface structure as a function of material (metal and coating materials) and temperature are examined.

In the past year, emphasis was placed on a detailed analysis and description of the Cs/SiC interface formation process.


Reactor Physics Studies For The Afci Reactor-Accelerator Coupling Experiments Project, Denis Beller Jan 2007

Reactor Physics Studies For The Afci Reactor-Accelerator Coupling Experiments Project, Denis Beller

Transmutation Sciences Physics (TRP)

The specific research objective of this three-year project is to design and conduct accelerator driven experiments, which will help demonstrate in the U.S. the ability to design, compute, and conduct ADSS experiments and to predict and measure source importance, coupling efficiency, sub-critical reactor kinetics and source-driven transients. In addition, databases will be created for both steady state and transient ADSS experiments for the nuclear community to develop and test new computational codes and methods, and the importance of a driving neutron source in various regions of different subcritical assemblies will be mapped. Experiments will be conducted and compared to calculations …


Criticality Studies For Urex Processes, Denis Beller Jan 2007

Criticality Studies For Urex Processes, Denis Beller

Separations Campaign (TRP)

The completion of criticality experiments for mixtures of transuranic actinides (TRU–includes Np, Pu, Am, and Cm) that will be created during the separation of used nuclear fuel may be a requirement in order to construct prototype plants for the Global Nuclear Energy Partnership. In this program and the Advanced Fuel Cycle Research and Development (AFC R&D) program that supports it, economic and environmental methods are being developed to reduce the impact of waste from commercial nuclear fuel cycles.

Recycling of used fuel by chemically separating it into U, fission products, and TRU would be the first step in this new …


Urban Sustainability Through Green Building, Andrea Anzalone, Virginia Sawyer, Robert Woolsey Jan 2007

Urban Sustainability Through Green Building, Andrea Anzalone, Virginia Sawyer, Robert Woolsey

UNLV Theses, Dissertations, Professional Papers, and Capstones

This analysis is presented on urban sustainability through the use of "green building" in the City of Las Vegas, Nevada. This paper discusses the current practices used by the City of Las Vegas and compares them to the top 5 sustainable cities throughout the United States (as identified by the U.S. Green Building Council). Through comparison of nationwide initiatives and policies, this paper outlines recommendations the City of Las Vegas can adopt to increase their position as one of the leading sustainable cities.


Cooperative Conservation: Increasing Capacity Through Community Partnerships -- Interagency Volunteer Program: Quarterly Progress Report, Period Ending December 31, 2006, Margaret N. Rees Dec 2006

Cooperative Conservation: Increasing Capacity Through Community Partnerships -- Interagency Volunteer Program: Quarterly Progress Report, Period Ending December 31, 2006, Margaret N. Rees

Get Outdoors Nevada

  • Volunteer database increased 8% over last quarter. Database now contains 2,923 records.
  • Website activity increased, recording an average of 51,568 hits per month, with an average of 4,985 pages viewed per month (12.4% increase in pages viewed).
  • Team charter approved and signed by federal managers and IVP team.
  • Volunteer orientation and training in 11 subject areas delivered to 80 volunteers.
  • Recognition Banquet and Awards Ceremony recognized 180 volunteers.
  • Volunteer event list revised for 2007.