Physical Sciences and Mathematics Commons^™

Impact Of Alteration Phase Formation And Microbial Activity On The Fate And Transport Of The Actinides And Fission Products: Alteration Phase Analysis, James Cizdziel, Klaus J. Stetzenbach, Thomas Williams, Abe Van Luik

Publications (YM)

The study of the behavior and movement of radionuclides in the environment is significant to many projects of interest to Southern Nevada, especially for the proposed Yucca Mountain Repository, as well as to the nation-wide issues of radiological releases from a variety of scenarios. Understanding and predicting the release, transport, and fate of radionuclides, particularly the actinide elements, in the Mojave/Great Basin geology is an extremely challenging, multi-faceted problem. In support of the national program to deepen our understanding of the behavior of radionuclides in the environment and to better predict the performance of a geological repository at Yucca Mountain, …

Characterization Of Microbial Activity, Mark P. Buttner, Patricia Cruz, Klaus J. Stetzenbach, Abe Van Luik, Thomas Williams, Amy J. Smiecinski

Publications (YM)

The overall goal of this study is to investigate the phenomena that affect the fate and transport of radionuclides in the environment. The objective of this task, “Characterization of Microbial Activity”, is to develop a molecular biological method for the characterization of the microbial population indigenous to the Yucca Mountain Project site, with emphasis in detection and measurement of species or groups of microorganisms that could be involved in actinide and/or metal reduction, and subsurface transport. Subtasks consist of QA planning and preparation, and literature review. This task is part of a cooperative agreement between the UNLV Research Foundation and …

Monitoring Temporal Change In Riparian Vegetation Of Great Basin National Park, E. A. Beever, D. A. Pyke, J. C. Chambers, F. Landau, S. D. Smith, K. Murray

Life Sciences Faculty Research

Disturbance in riparian areas of semiarid ecosystems involves complex interactions of pulsed hydrologic flows, herbivory, fire, climatic effects, and anthropogenic influences. We resampled riparian vegetation within ten 10-m × 100-m plots that were initially sampled in 1992 in 4 watersheds of the Snake Range, east central Nevada. Our finding of significantly lower coverage of grasses, forbs, and shrubs within plots in 2001 compared with 1992 was not consistent with the management decision to remove livestock grazing from the watersheds in 1999. Change over time in cover of life-forms or bare ground was not predicted by scat counts within plots in …

Ramping Up Assessment At The Unlv Libraries, Jeanne M. Brown

Library Faculty Research

Purpose – Sets out to describe the development of an assessment program at UNLV Libraries and current assessment activities.

Design/methodology/approach – Assessment activities are first placed in organizational context, distinguishing between assessment initiated by departments, and assessment done library-wide. Common expressions of resistance to assessment are noted, followed by the library and campus context relating to assessment. The impact of technology and of the LibQual+ survey is discussed.

Findings – Assessment activities at UNLV Libraries have strengthened and diversified over the last several years, thanks to several factors including the guidance of its dean, the development of technology and human …

Southern Nevada Interagency Volunteer Program, Public Lands Institute

Get Outdoors Nevada

To encourage, support, and build volunteerism to conserve, protect, enhance, and foster an appreciation of the diverse natural, cultural, and recreational areas in Southern Nevada.

Campus Community And Their Responsibility To Our Public Lands, Mark Valentin

Presentations (PLI)

• To heighten awareness of UNLV’s community on the laws governing the uses of public lands and the personal liabilities associated with such use.
• To provide the campus community with the most efficient permitting service possible.
• To provide accurate, concise permit information to the appropriate agency.

Regional Open Space & Trails Workgroup Presentation, Public Lands Institute

Presentations (PLI)

The Public Lands Institute is dedicated to strengthening the national fabric that is essential for the protection, conservation, and management of public lands.

Connecting Hearts, Minds, & Hands To Public Lands, Public Lands Institute

Presentations (PLI)

The Public Lands Institute is dedicated to strengthening the national fabric that is essential for the protection, conservation, and management of public lands.

Inventing The Future 2005 Planning Retreat, Public Lands Institute

Presentations (PLI)

• Foster an integrated, holistic approach to managing and stewarding public lands.
• Focus initially on externally funded cooperative conservation projects, research initiatives, and capital improvement projects.
• Attract projects that are local, regional, and national in scope.

Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Quarterly Progress Report, Period Ending March 31, 2005, Margaret N. Rees

Oliver Ranch Project

Assist in project coordination between numerous stakeholders such as the Clark County School System, Desert Research Institute, Community College of Southern Nevada, UNR Cooperative Extension, Nevada State College, local museums, state parks, non-profit organizations, federal agencies, and the public to ensure appropriate educational curricular activities and venues are provided for in the conceptual design of the School and the Wild Horse and Burro facility where appropriate as well as assist in the NEPA process as needed. The activities will be conducted at least in part by university faculty, staff and students as part of the university’s research, teaching, and service …

Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Quarterly Progress Report, Period Ending September 30, 2005, Margaret N. Rees

Oliver Ranch Project

Executive Summary

Activity highlights during the first quarter of Year Two include the following actions toward task agreement deliverables:

• Agenda and minutes prepared and distributed for three core group meetings
• Wild horse and burro curriculum completed and vetted through local, regional, and national levels
• Historical curriculum completed and ready for review by core group
• Two RRDLC PowerPoint presentations coordinated, written, and illustrated by Public Lands Institute staff for BLM presentations to the Clark County School District Executive Cabinet and the Board of Trustees.
• RRDLC informational handouts provided to community members, teachers, and students at Joshua Jubilee community event and Clark …

Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees

Oliver Ranch Project

Executive Summary

Activity highlights during the first quarter of Year Two include the following actions toward task agreement deliverables:

• Agenda and minutes prepared and distributed for two core group meetings
• Historical curriculum 100% completed
• Cultural curriculum 100% completed
• Night sky curriculum 50% completed
• Green Building curriculum 25% completed
• Communications/Outreach Plan revised and prioritized
• RRDLC newsletter under final review by BLM state office

Oliver Ranch Science School Complex & Wild Horse And Burro Facility: Annual Progress Report, Year Ending June 30, 2005, Margaret N. Rees

Oliver Ranch Project

Assist in project coordination between numerous stakeholders such as the Clark County School System, Desert Research Institute, Community College of Southern Nevada, UNR Cooperative Extension, Nevada State College, local museums, state parks, non-profit organizations, federal agencies, and the public to ensure appropriate educational curricular activities and venues are provided for in the conceptual design of the School and the Wild Horse and Burro facility where appropriate as well as assist in the NEPA process as needed. The activities will be conducted at least in part by university faculty, staff and students as part of the university’s research, teaching, and service …

Best Practices In Multi-Agency Volunteer Programs, Lanelda Rolley, Donna Grady, Chuck Williams

Interagency Science and Research Strategy

• Strengthen the national fabric in support of public lands.

• Provide people of all ages with opportunities to participate in the enjoyment, protection, and responsible use of our public lands.

Technical Risk Information: Decision Tool Or Rhetorical Ammunition? Undisputed Facts In The Yucca Mountain Debate, David M. Hassenzahl, Denise Tillery, Paulette Laidler

Public Policy and Leadership Faculty Research

This paper examines how both opponents and proponents of the proposed high-level nuclear waste repository at Yucca mountain Nevada claim that uncontroversial information supports their conflicting positions. Four pieces of information in particular are claimed by both sides: the distance of the proposed site from Las Vegas, the volume of waste that has been produced, the threat of terrorism since 9/11/01, and the occurrence of an earthquake in early 2002. Possible explanations for the difference include naive positivism, social constructionism, persistent beliefs and implicit warrants. The latter two models better explain observed knowledge/preference states. If so, more or better information …

Microwave Backscatter Modeling Of Erg Surfaces In The Sahara Desert, Haroon Stephen, David G. Long

Public Policy and Leadership Faculty Research

The Sahara Desert includes large expanses of sand dunes called ergs. These dunes are formed and constantly reshaped by prevailing winds. Previous study shows that Saharan ergs exhibit significant radar backscatter (σ°) modulation with azimuth angle (f). We use σ° measurements observed at various incidence angles and f from the NASA Scatterometer (NSCAT), the SeaWinds scatterometer, the ERS scatterometer (ESCAT), and the Tropical Rainfall Measuring Mission's Precipitation Radar to model the σ° response from sand dunes. Observations reveal a characteristic relationship between the backscatter modulation and the dune type, i.e., the number and orientation of the dune slopes. Sand dunes …

Modeling Microwave Emissions Of Erg Surfaces In The Sahara Desert, Haroon Stephen, David G. Long

Public Policy and Leadership Faculty Research

Sand seas (ergs) of the Sahara are the most dynamic parts of the desert. Aeolian erosion, transportation, and deposition continue to reshape the surface of the ergs. The large-scale features (dunes) of these bedforms reflect the characteristics of the sand and the long-term wind. Radiometric emissions from the ergs have strong dependence on the surface geometry. We model the erg surface as composed of tilted rough facets. Each facet is characterized by a tilt distribution dependent upon the surface roughness of the facet. The radiometric temperature (T(b)) of ergs is then the weighted sum of the T(b) from all the …

Southern Nevada Guide: Tree Selection And Care, City Of Las Vegas, Nevada

Publications (SD)

Trees for Tomorrow was created to educate Southern Nevada residents on the benefits of trees and to help homeowners choose the right trees for their landscape setting. The goal of this booklet is to help homeowners successfully select and establish trees. This Centennial edition recognizes the 100-year celebration of the founding of the City of Las Vegas. Planting trees is a necessary adaptation to human settlement in arid environments. A strong, healthy community forest is built tree by tree, home by home. Tree canopies help to reduce energy demands, reduce water demands, reduce local air temperatures, reduce air pollution, provide …

Conservation Element Of The Las Vegas 2020 Master Plan, City Of Las Vegas, Nevada

Publications (SD)

There is a dual purpose to the Las Vegas 2020 Master Plan Conservation Element. The first purpose is to address the requirements of state law, as provided in the Nevada Revised Statutes (NRS) 278.150(4). This section of the NRS requires that governing bodies in Nevada counties with a population of 400,000 or more ensure that their master plans address a stipulated list of subjects, including a conservation plan.

Application Of Meshless Methods For Thermal Analysis, Darrell Pepper, Bozidar Sarler

Mechanical Engineering Faculty Research

Many numerical and analytical schemes exist for solving heat transfer problems. The meshless method is a particularly attractive method that is receiving attention in the engineering and scientific modeling communities. The meshless method is simple, accurate, and requires no polygonalisation. In this study, we focus on the application of meshless methods using radial basis functions (RBFs) — which are simple to implement — for thermal problems. Radial basis functions are the natural generalization of univariate polynomial splines to a multivariate setting that work for arbitrary geometry with high dimensions. RBF functions depend only on the distance from some center point. …

Radiation Transport Modeling Using Parallel Computational Techniques, William Culbreth, Denis Beller

Reactor Campaign (TRP)

One of the most significant tools available for the design and analysis of accelerator-driven systems, such as the systems proposed for transmutation, is the high-energy particle transport code MCNPX. The MCNPX code suite, developed by the national laboratories, allows researchers and engineers to model the complex interactions of high-energy particles with the target and related systems, including the spallation reaction and subsequent neutron multiplication expected in the accelerator targets.

The next stage in the development of the MCNPX code suite is to validate the code by comparing the theoretical predictions from the models with experimental observations. Additionally, the nuclear database, …

University Of Nevada, Las Vegas Transmutation Research Program: Annual Report Academic Year 2004-2005, Anthony Hechanova, Kathy Lauckner

Transmutation Research Program Reports (TRP)

It is my pleasure to present the UNLV Transmutation Research Program’s fourth annual report that highlights the academic year 2004 – 2005. Supporting this document are the many technical reports and scientific papers that have been generated over the past three years.

In the fourth year of our program, we added 11 new research tasks and saw the conclusion of 8 of the initial 16 independent student research tasks started in 2001 and 2002. In all, the program has sponsored to their conclusion 28 M.S. and 2 Ph.D. degrees. The program supported 58 graduate students and 13 undergraduates in 6 …

Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Allen L. Johnson, Dale L. Perry

Transmutation Sciences Materials (TRP)

There is an active international interest in lead-bismuth eutectic and similar liquid lead systems because of the relevance to the transmutation of nuclear waste, fast reactors, and spallation neutron sources.

Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. For lead bismuth eutectic (LBE) systems, there is an additional challenge because the corrosive behaviors of materials in LBE are not well understood. Most of the available information on LBE systems has come from the Russians, who have over 80 reactor-years experience with LBE coolant in their Alpha-class submarine reactors. The Russians found …

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The primary objective of this task was to evaluate the effects of environmental and mechanical parameters on environment induced degradations of candidate target structural materials for applications in spallation-neutron-target systems. The materials selected for evaluation and characterization were martensitic stainless steels including Alloys HT-9, EP-823, and 422.

Accelerator-driven transmutation systems involve bombarding a target material such as molten lead-bismuth-eutectic (LBE) by a proton beam, thereby producing neutrons. The molten LBE target will be contained in a subsystem structural container made of a suitable material such as Alloys HT-9, EP-823, and 422. During the transmutation process, the target structural material may …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The corrosion of structural materials is a major concern for the use of lead-bismuth eutectic (LBE) systems for nuclear applications such as in transmuter targets or fast reactors. Corrosion in liquid metal systems can occur through various processes, including, for example, dissolution, formation of inter-metallic compounds at the interface, and penetration of liquid metal along grain boundaries. Predicting the rate of these processes depends on numerous system operational factors: temperature, system geometry, thermal gradients, solid and liquid compositions, and velocity of the liquid metal, to name a few. Corrosion, along with mechanical and/or hydraulic factors, often contributes to component failure. …

Development Of A Mechanistic Understanding Of High-Temperature Deformation Of Alloy Ep-823, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

During the transmutation process, a significant amount of heat can be generated in a molten lead-bismuth-eutectic (LBE) target, which will be contained in a subsystem structural container made of a suitable martensitic iron-chromium-molbdenum (Fe-Cr-Mo) stainless steel such as Alloys EP-823, HT-9 and 422. These materials will be subjected to high tensile stresses while they are in contact with the molten LBE at temperatures ranging between 400 and 600^oC. Therefore, a research program was conducted to evaluate the deformation characteristics of all three alloys in properly heat-treated conditions at temperatures relevant to the operating conditions.

Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic, Yingtao Jiang, Bingmei Fu

Transmutation Sciences Materials (TRP)

Although liquid lead-bismuth eutectic (LBE) is a good candidate for the coolant that can be employed in a subcritical transmutation blanket, it is known to be very corrosive to stainless steel, the material used in the containment structure. To mitigate this problem, trace levels of oxygen can be introduced into the system, causing the formation of a protective oxide layer at the interface between the LBE and steel. The proper formation of this oxide layer largely depends on the accurate measurement and subsequent control of the oxygen concentration in liquid LBE.

Yttria Stabilized Zirconia (YSZ) oxygen sensors, using molten bismuth …

Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements, Ajit K. Roy

Transmutation Sciences Materials (TRP)

Engineering metals and alloys, when subjected to tensile loading beyond a limiting value, undergo plastic deformation resulting in lattice defects such as voids and dislocations. These imperfections interact with the crystal lattice, producing a higher state of internal stress, also known as residual stress, which can be associated with reduced ductility. Residual stresses are also generated in welded structures due to rapid solidification and resultant dissimilar metallurgical microstructures between the weld and the base metals. Development of these internal stresses is often influenced by incompatible permanent strain resulting from thermal and mechanical operations associated with welding and plastic deformation. These …

Fundamental And Applied Experimental Investigations Of Corrosion Of Steel By Lbe Under Controlled Conditions: Kinetics, Chemistry Morphology, And Surface Preparation, John Farley, Allen L. Johnson, Dale L. Perry

Transmutation Sciences Materials (TRP)

Advanced nuclear processes such the transmutation of nuclear waste, fast reactors, and spallation neutron sources require advanced materials systems to contain them. In particular, a successful program in nuclear waste processing that includes transmutation in accelerator-driven systems and fast reactors requires structural materials that are stable in the presence of non-moderating coolants. A prime candidate for such a coolant is Lead Bismuth Eutectic (LBE).

Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. For LBE systems, there is an additional challenge because the corrosive behaviors of materials in lead bismuth are not …

Effect Of Silicon Content On The Corrosion Resistance And Radiation- Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems, Ajit K. Roy

Transmutation Sciences Materials (TRP)

This task is focused on the evaluation of the effect of Si content on the corrosion behavior and radiation-induced embrittlement of martensitic steels having chemical compositions similar to that of modified 9Cr-1Mo steel. Numerous state-of-the-art experimental techniques are currently being planned to be employed to achieve the desired research goal.