Physical Sciences and Mathematics Commons^™

Unlv Magazine, Holly Ivy De Vore, Nancy Syzdek, Patrice E.M. Hollrah, Douglas Unger, Eugene Moehring, Gillian Silver, John F. Gallagher, Lori Bachand, Gian Galassi, Hal Rothman, Mark Hoversten, Phil Hagen, Donna Mcaleer, Suzan Dibella

UNLV Magazine

No abstract provided.

Cooperative Conservation - Interagency Volunteer Program Quarterly Progress Report: Period Ending September 30, 2004, Margaret N. Rees

Get Outdoors Nevada

Collaboration with Interagency Team

Although the task agreement formally commenced June 30, 2004, the agreement was not fully executed by both parties until July 29, 2004. In the first three months of this agreement, UNLV representatives have met with or communicated via email with the Interagency Volunteer Team on numerous occasions. At the first meeting on July 13, 2004, Government Technical Representative Bobbie Antonich and UNLV Public Lands Initiative Director Nancy Flagg met with the interagency team to discuss the overall goals for the Interagency Volunteer Program (IVP). The team was brought up-to-date on the status of the task agreement, …

Evaluation Of Fluorapatite As A Waste-Form Material: Fourth Quarter Report, June 1 - September 30, 2004, Dennis W. Lindle, Oliver Hemmers

Separations Campaign (TRP)

Fluorapatite, fluorinated calcium phosphate, has been identified as a potential matrix for the entombment of the zirconium fluoride fission product waste stream from the proposed FLEX process. If the efficacy of fluorapatite-based waste-storage can be demonstrated, then new and potentially more-efficient options for handling and separating high-level wastes, based on fluoride-salt extraction, will become feasible. This proposal will develop a dual-path research project to develop a process to fabricate a synthetic fluorapatite waste form for the ZrF₄, FP waste stream, characterize the waste form, examine its performance under environmental conditions, and correlate the behavior of the waste form …

Development Of A Systems Engineering Model Of The Chemical Separations Process: Final Report, Yitung Chen, Sean Hsieh

Separations Campaign (TRP)

The whole chemical separation process is complex to the point that definitely requires certain level of systematic coordination. To perform smoothly and meet the target extraction rates among those processes, this research proposed a general-purpose systems engineering model.

A general purposed systems engineering model, Transmutation Research Program System Engineering Model Project (TRPSEMPro), was developed based on the above design concept. The system model includes four main parts: System Manager, Model Integration, Study Plan, and Solution Viewer. TRPSEMPro can apply not only to chemical separation process, but also a general system model.

Software engineering and Object Oriented Analysis and Design (OOA&D) …

Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic: Quarterly Progress Report (July 1 – Sept. 30, 2004), Yingtao Jiang, Bingmei Fu

Transmutation Sciences Materials (TRP)

Dr. Jiang Ma and Mr. Xiaolong Wu worked in LANL between July 1 and Sept. 15 to conduct the experiment. Test of the corrosion of different materials in LBE was performed. The influence of the process of gas introduction to the LBE was studied. Data analysis work was performed based on accumulated data. In the same time, progress has been made in the simulation for transport in oxygen mixing, and one paper was presented in a conference. Another paper was composed and submitted to IEEE International Symposium of Circuits and Systems for the track Chemical Sensors. Preparation of a paper …

Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Sean Hsieh

Separations Campaign (TRP)

The whole chemical separation process is complex to the point that definitely requires certain level of systematic coordination. To perform smoothly and meet the target extraction rates among those processes, this research proposed a general-purpose systems engineering model.

A general purposed systems engineering model, Transmutation Research Program System Engineering Model Project (TRPSEMPro), was developed based on the above design concept. The system model includes four main parts: System Manager, Model Integration, Study Plan, and Solution Viewer. System Manager supervises all the case (problem) creation, and functionality definition. Model Integration identifies chemical extraction processes and their execution sequence. Study Plan is …

Unlv Public Lands Initiative, Nancy Flagg

Presentations (PLI)

• The Public Lands Initiative is providing management and oversight for selected SNPLMA projects that fit UNLV’s educational and research strengths and which are suitable for drawing upon the expertise of university faculty, staff, and students.

Public Lands Initiative Overview, 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.

Red Rock Desert Learning Center Core Group Meeting: September 21, 2004, Red Rock Desert Learning Center

Reports (RRLC)

1. Introductions (5 min.)
2. Approval of Minutes from August 17 Meeting (5 minutes)
3. Potential Tie-in with City of Las Vegas New Directions YouthArts Program –
   Markus Tracy (20 min.)
4. Presentation of Education in the Environment Curriculum Matrix and correlation to
   RRDLC curriculum development – Jeanne Klockow (30 min.)
5. Discussion of Policy-making Board for the Center – Michael Reiland (15 min.)
6. Discussion of Observatory Location – Michael Reiland (25 min.)
7. Standing Reports (20 minutes)
   A. Line and Space Architects Update – Les Wallach/Henry Tom
   B. UNLV/CESU Update – Nancy Flagg
   C. RRCNCA Capital Improvements Update – BLM
8. Committee Reports (10 min.)
   A. …

Education In The Environment Partnership, Public Lands Institute

Presentations (PLI Education)

• Update on Oliver Ranch
• Update on Forever Earth
• Update on WOW on the Water

Influence Of Lithophysae Geometry And Distribution On Mechanical Properties Of Topopah Spring Tuff, Mohammad Shahidul Islam, Justin Fenton, Moses Karakouzian, Jaime Gonzalez, Amy J. Smiecinski, Raymond E. Keeler

Publications (YM)

The current Site Recommendation study for the proposed high level nuclear waste repository at Yucca Mountain locates the repository emplacement drifts approximately 81% within the lower lithophysal unit of the Topopah Springs Formation (Tptpll), 4% within the upper lithophysal unit of the Topopah Springs Formation (Tptpul), and roughly 15% within the middle, non-lithophysal unit (Tptpmn) of the same formation. A major geomechanical issue facing the Yucca Mountain Project is to understand the thermomechanical behavior of lithophysal tuff, which comprises roughly 85% of the repository host rock.

A Fast And Simple Algorithm For Computing M Shortest Paths In Stage Graph, M. Sherwood, Laxmi P. Gewali, Henry Selvaraj, Venkatesan Muthukumar

Electrical & Computer Engineering Faculty Research

We consider the problem of computing m shortest paths between a source node s and a target node t in a stage graph. Polynomial time algorithms known to solve this problem use complicated data structures. This paper proposes a very simple algorithm for computing all m shortest paths in a stage graph efficiently. The proposed algorithm does not use any complicated data structure and can be implemented in a straightforward way by using only array data structure. This problem appears as a sub-problem for planning risk reduced multiple k-legged trajectories for aerial vehicles.

Nondipole Effects In The Photoionization Of Xe 4d5/2 And 4d3/2: Evidence For Quadrupole Satellites, Oliver Hemmers, Renaud Guillemin, D. Rolles, A. Wolska, Dennis W. Lindle, K. T. Cheng, W. R. Johnson, H. L. Zhou, S. T. Manson

Environmental Studies Faculty Publications

Measurements of nondipole parameters in spin-orbit-resolved Xe 4d photoionization demonstrate dynamical differences arising from relativistic effects. The experimental data do not agree with relativistic random-phase approximation calculations of single ionization dipole and quadrupole channels. It is suggested that the discrepancy is due to the omission of multiple-excitation quadrupole channels, i.e., quadrupole satellite transitions.

Afci Quarterly Input – Unlv July Through September, 2004, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Transmutation Research Program Reports (TRP)

Quarterly report highlighting research projects, activities and objectives of the Transmutation Research Program at the Nuclear Science & Technology Division, Harry Reid Research Center.

The University of Nevada, Las Vegas supports the AFCI through research and development of technologies for economic and environmentally sound refinement of spent nuclear fuel. The UNLV program has four components: infrastructure, international collaboration, student-based research, and management and program support.

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, July 2004 To September 2004, Kenneth Czerwinski, Earl Wolfram

Fuels Campaign (TRP)

This project will examine inert fuels containing ZrO₂ and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO₂. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10 % of ²³⁹Pu. Ceramics will be synthesized and characterized based on the reactor physics results. The solubility the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, will be investigated in a manner to provide …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus

Fuels Campaign (TRP)

This progress report presents results of analysis performed within the framework of “Dissolution, Reactor, and Environmental Behavior of ZrO₂-MgO Inert Fuel Matrix” project managed by University of Nevada at Las Vegas, Harry Reid Center for Environmental Studies.

The BGU working program includes the following four tasks:

1. Benchmark of computational tools

2. Determination of fissile Pu loading

3. Evaluation of burnable poison designs

4. Evaluation of reactivity feedback coefficients

This progress report presents the results of Task 1. The main objective of this task is to confirm the validity of the ELCOS ¹ code system for inert matrix …

Probing Cation Antisite Disorder In Gd2ti2o7 Pyrochlore By Site-Specific Nexafs And Xps, Ponnusamy Nachimuthu, S. Thevuthasan, Mark H. Engelhard, W. J. Weber, D. K. Shuh, N. M. Hamdan, B. S. Mun, E. M. Adams, D. E. Mccready, V. Shutthanandan, Dennis W. Lindle, G. Balakrishnan, R. C. Ewing

Chemistry and Biochemistry Faculty Research

Disorder in Gd₂Ti₂O₇ is investigated by near-edge x-ray-absorption fine structure (NEXAFS) and x-ray photoelectron spectroscopy (XPS). NEXAFS shows Ti⁴⁺ ions occupy octahedral sites with a tetragonal distortion induced by vacant oxygen sites. O 1s XPS spectra obtained with a charge neutralization system from Gd₂Ti₂O₇(100) and the Gd₂Ti₂O₇ pyrochlore used by Chen et al. [Phys. Rev. Lett. 88, 105901 (2002)], both yielded a single peak, unlike the previous result on the latter that found two peaks. The current results give no evidence for …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Fourth Quarterly Report 06/01/2004-08/31/2004, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Education In The Environment: A Hands-On Student Research And Outdoor Learning Experience: Quarterly Progress Report, Period Ending August 31, 2004, Environmental Education Strategy For Nevada

Reports (PLI Education)

In the first three months of this agreement, UNLV has met with the Outside Las Vegas Environmental Education Committee to establish the duties of and create detailed job announcements for the project managers for the Environmental Education Strategy and for the Forever Earth/WOW Program. Although the university had planned to meet with the committee at its June meeting, that meeting was cancelled due to summer scheduling conflicts among the committee members. Subsequently, Dr. Peg Rees and Nancy Flagg met with the committee on July 14,2004. The committee was brought up-to-date on goals and deliverables of the task agreement, UNLV’s role …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Trp Final Report 09/01/2003-08/31/2004, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Development Of Dose Conversion Coefficients For Radionuclides Produced In Spallation Neutron Sources: Quarterly Progress Report 5/1/04 – 8/31/04, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

The research consortium comprised of representatives from several universities and national laboratories has successfully generated internal and external dose conversion coefficients for twenty radionuclides produced in spallation neutron sources. These dose coefficients fill data gaps exist in Federal Guide Report No. 11 and in Publications 68 and 72 of the International Commission on Radiological Protection (ICRP). Currently, more nuclear data is needed for the rare radionuclides produced from a mercury target.

Oliver Ranch Core Group Meeting: August 17, 2004, Red Rock Desert Learning Center

Reports (RRLC)

1. Introductions (5 minutes)
2. Approval of Minutes from June 15 Meeting (5 minutes)
3. Review of Draft Talking Points/FAQ – Nancy Flagg (30 min)
4. Discussion of Wild Horse and Burro Facility – Billie Young (30 min.)
5. Standing Reports (30 minutes)
   A. Line and Space Update – Les Wallach/Henry Tom
   B. UNLV/CESU Update – Peg Rees/Nancy Flagg
   C. RRCNRA Capital Improvements Update – Mark Morse/Michael Reiland
6. ORSS Committee Reports (15 minutes)
   A. Design Oversight – David Frommer
   B. Educational Programs – Paul Buck
   C. Fund-Raising & Partnerships – Blaine Benedict
   D. NEPA – Charles Carroll
   E. Operations – Jack Ramsey
   F. Other Uses …

Neutron Multiplicity Measurements For The Afci Program Quarterly Progress Report June-August 2004, Denis Beller

Transmutation Sciences Physics (TRP)

The U.S. Advanced Fuel Cycle Initiative (AFCI) is a program to develop economic and environmental methods to reduce the impact of waste from commercial nuclear fuel cycles. One concept for near-complete destruction of waste isotopes from used nuclear fuel is acceleratordriven transmutation. High-power accelerators would be used to produce high-energy charged particles, which then collide with heavy metal targets to create a cascade of neutrons. These neutrons then cause a nuclear chain reaction in subcritical systems. Fission neutrons then transmute fissile waste isotopes as well as other problematic isotopes such as technetium-99 and iodine-129. To design these systems, complex reactor …

Inside Unlv, Cate Weeks, Carol C. Harter, Diane Russell, Holly Ivy De Vore

Inside UNLV

No abstract provided.

Vegetation Characteristics Associated With Small Mammal Populations In The Las Vegas Wash, Christine Therese Herndon

UNLV Theses, Dissertations, Professional Papers, and Capstones

Percent litter, average litter depth, percent bare ground, vegetation density, vegetation canopy, and distance to an ecotone boundary were measured and compared to small mammal capture locations in the Las Vegas Wash. Neotoma lepida appear to be greatly dependent upon the foliage litter of T. ramosissima. Alternatively, ecotone boundaries appear to be the most important factor affecting Dipodomys merriami distributions. Peromyscus eremicus distributions may be predicted based on vegetation density and increased canopy during shorter, winter torpor periods. Chaetodipus penicillatus were consistently associated with dense, seed-bearing vegetation, although C. penicillatus is extremely opportunistic and vegetation density should not limit their …

Experimental Investigation Of Time Dependent Behavior Of Welded Topopah Spring Tuff, Lumin Ma

Publications (YM)

Four types of laboratory tests have been performed. Specimens were attained from four lithophysal zones of the welded Topopah Spring Tuff unit at Yucca Mountain, Nevada: upper lithophysal, middle nonlithophysal, lower lithophysal and lower nonlithophysal zones. Two types of tests are conducted to study time-dependent behavior: constant strain rate and creep tests. Sixty five specimens from the middle nonlithophysal zone were tested at six strain rates: 10 , 10 , 10 , 10 , 10 , and 10 . Test durations range from 2 seconds to 7 days. Fourteen specimens from middle nonlithophysal, lower lithophysal and lower nonlithophysal zones are …

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

Transmutation Sciences Physics (TRP)

In the RACE Project of the U.S. Advanced Fuel Cycle Initiative (AFCI), a series of accelerator driven subcritical systems (ADSS) experiments will be conducted at the Idaho State University’s Idaho Accelerator Center (ISU-IAC), at the University of Texas (UT) at Austin, and at the Texas A&M University. In these experiments we will use electron accelerators to induce bremsstrahlung photon-neutron reactions in heavy-metal targets; this source of about 10¹² to 10¹³ n/s will then initiate fission reactions in the subcritical systems. These systems will include a compact, transportable assembly at ISU and TRIGA reactors at UT-Austin and Texas A&M. …

Oliver Ranch Core Group Meeting: July 20, 2004, Red Rock Desert Learning Center

Reports (RRLC)

1. Introductions (5 minutes)
2. Approval of Minutes from June 15 Meeting (5 minutes)
3. Review of Draft Talking Points/FAQ – Nancy Flagg (30 min)
4. Discussion of Wild Horse and Burro Facility – Billie Young (30 min.)
5. Standing Reports (30 minutes)
   A. Line and Space Update – Les Wallach/Henry Tom
   B. UNLV/CESU Update – Peg Rees/Nancy Flagg
   c. RRCNRA Capital Improvements Update – Mark Morse/Michael Reiland
6. ORSS Committee Reports (15 minutes)
   A. Design Oversight – David Frommer
   B. Educational Programs – Paul Buck
   C. Fund-Raising & Partnerships – Blaine Benedict
   D. NEPA – Charles Carroll
   E. Operations – Jack Ramsey
   F. Other Uses …

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Annual Progress Report (May 2003 – May 2004), Ajit K. Roy

Transmutation Sciences Materials (TRP)

As indicated in the original proposal, the primary objective of this task was to evaluate the effect of hydrogen on environment-assisted cracking of candidate target structural materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The materials selected for evaluation and characterization were martensitic stainless steels including Alloy EP 823, HT-9, and Type 422 stainless steel. The susceptibility to stress corrosion cracking (SCC) of these materials were evaluated in neutral and acidic aqueous environments using smooth and notched tensile specimens under constant-load (CL) and slow-strain-rate (SSR) conditions. Further, the …

Spectroscopic And Microscopic Investigation Of The Corrosion Of 316/316l Stainless Steel By Lead-Bismuth Eutectic (Lbe) At Elevated Temperatures: Importance Of Surface Preparation, Allen L. Johnson, Denise Parsons, Julia Manzerova, Dale L. Perry, Daniel Koury, Brian D. Hosterman, John Farley

Transmutation Sciences Materials (TRP)

The corrosion of steel by lead–bismuth eutectic (LBE) is an important issue in proposed nuclear transmutation schemes. Russian scientists at the IPPE exposed steel samples to oxygen-controlled LBE at temperatures up to 823 K and exposure times up to 3000 h. We have characterized these post-exposure steel samples and unexposed controls, using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray photoelectron spectroscopy (XPS). Previous researchers have investigated the corrosion by LBE of steel of varying composition. In the present work, we compared two samples having the same composition (standard nuclear grade 316/316L) but different surface preparation: a cold-rolled …