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Articles 151 - 180 of 266

Full-Text Articles in Radiochemistry

Molecular Forensic Science Analysis Of Nuclear Materials, Dallas Reilly Dec 2012

Molecular Forensic Science Analysis Of Nuclear Materials, Dallas Reilly

UNLV Theses, Dissertations, Professional Papers, and Capstones

Concerns over the proliferation and instances of nuclear material in the environment have increased interest in the expansion of nuclear forensics analysis and attribution programs. A new related field, molecular forensic science (MFS) has helped meet this expansion by applying common scientific analyses to nuclear forensics scenarios. In this work, MFS was applied to three scenarios related to nuclear forensics analysis. In the first, uranium dioxide was synthesized and aged at four sets of static environmental conditions and studied for changes in chemical speciation. The second highlighted the importance of bulk versus particle characterizations by analyzing a heterogeneous industrially prepared …


Evaluating Actinide Sorption To Graphite With Regards To Triso Repository Performance, Corey Christopher Keith Aug 2012

Evaluating Actinide Sorption To Graphite With Regards To Triso Repository Performance, Corey Christopher Keith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Graphite has the potential for inclusion in nuclear waste for disposal in waste repository settings. Implementation of High Temperature Gas-cooled Reactors contributes to this potential through use of TRISO fuel, if direct disposal of the graphite matrix surrounding the fuel is employed. The inclusion of the large mass and volume in the TRISO fuel waste form differs significantly from used light water reactor fuel waste forms, requiring new performance models to describe the behavior in a repository setting. The purpose of this study is to evaluate the potential for the graphite to improve actinide, specifically uranium and neptunium, retardation from …


Hrc Enews — 2012 Summer, Megan M. Iudice Jul 2012

Hrc Enews — 2012 Summer, Megan M. Iudice

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, and a "new faces" listing for new staff, affiliates, and researchers.


Hrc Enews — 2012 Spring, Megan M. Iudice Apr 2012

Hrc Enews — 2012 Spring, Megan M. Iudice

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, and a "new faces" listing for new staff, affiliates, and researchers.


National Center For Nuclear Security, Veraun Chipman, Amanda Klingensmith, Cathy Snelson Feb 2012

National Center For Nuclear Security, Veraun Chipman, Amanda Klingensmith, Cathy Snelson

NSTec UNLV Symposium

National Center for Nuclear Security (NCNS) Mission

•Chartered mission is to enhance the Nation’s verification and detection capabilities in support of nuclear arms control and nonproliferation through R&D activities at the NNSS
•Three focus areas
–Treaty Verification Technologies
–Nonproliferation Technologies
–Technical Nuclear Forensics


Detection Of Radioactive Isotopes From The Fukushima Daiichi Nuclear Power Plant In The Kittitas Valley Of Washington State, Randle Affholter, Michael Braunstein, Cesar Mendoza, Anne Johansen Feb 2012

Detection Of Radioactive Isotopes From The Fukushima Daiichi Nuclear Power Plant In The Kittitas Valley Of Washington State, Randle Affholter, Michael Braunstein, Cesar Mendoza, Anne Johansen

Student Published Works

Following the Fukushima Daiichi nuclear power plant disaster in March, 2011, various radioactive isotopes were emitted from the plant [Ewing, 2011]. We hypothesized that emissions would bind to particulate matter, which then could be dispersed by wind currents and deposited across the planet. We analyzed an aerosol sample collected with a high volume cascade impactor in the Kittitas Valley of Washington state. NaI(Tl) gamma spectrometry revealed the presence of the isotopes 132Te and 131I, consistent with the type of nuclear accident at Fukushima Daiichi.


Toward A Regional Radiocarbon Model For The East Texas Woodland Period, Robert Z. Selden Jr., Timothy K. Perttula Jan 2012

Toward A Regional Radiocarbon Model For The East Texas Woodland Period, Robert Z. Selden Jr., Timothy K. Perttula

CRHR: Archaeology

The East Texas Radiocarbon Database contributes to an analysis of tempo and place for Woodland era (ca. 500 B.C. - A.D. 800) archaeological sites within the region. The temporal and spatial distributions of calibrated radiocarbon (14C) ages (n=127) with a standard deviation (ΔT) of 61 from archaeological sites with Woodland components (n=51) are useful in exploring the development and geographical continuity of the peoples in East Texas, and lead to a refinement of our current chronological understanding of the period. While the analysis of the dates produces less than significant findings due to sample size, they are used …


The East Texas Caddo: Modeling Tempo And Place, Robert Z. Selden Jr., Timothy K. Perttula Jan 2012

The East Texas Caddo: Modeling Tempo And Place, Robert Z. Selden Jr., Timothy K. Perttula

CRHR: Archaeology

Analysis of the Caddo sample (n=889 dates) from the East Texas radiocarbon database is used to establish the tempo and place of Caddo era (ca. A.D. 800-1680) archaeological sites, site clusters, and communities across the region. The temporal and spatial distribution of radiocarbon ages from settlements, mound centers, and cemeteries across the region have utility in exploring the development and geographical continuity of the Caddo peoples; establishing the specific times when areas were abandoned or population sizes diminished; and defining times and areas illustrating an intensification in mound center construction and large cemeteries became a focus of community social practices.


Hrc Enews — 2012 Winter, Megan M. Iudice Jan 2012

Hrc Enews — 2012 Winter, Megan M. Iudice

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, and a "new faces" listing for new staff, affiliates, and researchers.


Intragroup Separation Of Trivalent Lanthanides And Actinides For Neutron Capture Experiments In Stockpile Stewardship Sciences, Narek Gharibyan Dec 2011

Intragroup Separation Of Trivalent Lanthanides And Actinides For Neutron Capture Experiments In Stockpile Stewardship Sciences, Narek Gharibyan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Knowledge of low-energy cross sections for stable and unstable nuclei in neutron-, γ- and ion induced reactions is important in both the simulation and radiochemistry diagnosis of nuclear device performance. This dissertation explores extraction chromatography and ion chromatography methods for the intragroup separation of trivalent actinides and lanthanides in support of cross section measurements for isotopes of interest. For trivalent actinides, americium (Am(III)) and curium (Cm(III)), separation is necessary to assist in experiments related to the measurement of neutron capture cross section for 241 Am and the production of 242 m Am/242g Am isomeric ratio. Extraction chromatography resins …


Spectroscopic Methods Of Process Monitoring For Safeguards Of Used Nuclear Fuel Separations, Jamie Lee Warburton Dec 2011

Spectroscopic Methods Of Process Monitoring For Safeguards Of Used Nuclear Fuel Separations, Jamie Lee Warburton

UNLV Theses, Dissertations, Professional Papers, and Capstones

To support the demonstration of a more proliferation-resistant nuclear fuel processing plant, techniques and instrumentation to allow the real-time, online determination of special nuclear material concentrations in-process must be developed. An ideal materials accountability technique for proliferation resistance should provide nondestructive, realtime, on-line information of metal and ligand concentrations in separations streams without perturbing the process. UV-Visible spectroscopy can be adapted for this precise purpose in solvent extraction-based separations.

The primary goal of this project is to understand fundamental URanium EXtraction (UREX) and Plutonium-URanium EXtraction (PUREX) reprocessing chemistry and corresponding UV-Visible spectroscopy for application in process monitoring for safeguards. By …


Undergraduate Research Opportunities Program 2011, Nicholle Booker, University Of Nevada, Las Vegas Aug 2011

Undergraduate Research Opportunities Program 2011, Nicholle Booker, University Of Nevada, Las Vegas

Undergraduate Research Opportunities Program (UROP)

Undergraduate Research Opportunities Program

On August 9, 2011 the UNLV College of Sciences will celebrate the accomplishments of undergraduate students participating in the Summer 2011 Undergraduate Research Opportunities Program (UROP) and the Research Experience For Undergraduates (REU) Program.

The public is invited to attend, beginning at 10:00 a.m.

Please join us to view student research posters. Student research topics include: biomedicine and human health, Nevada's fragile environment and ecosystems, climate change, stem cell research, microbiology, astrophysics, and many others.

Over 25 UNLV undergraduates and a cohort of 25 undergraduates selected from colleges and universities across the nation will mark the …


Synthesis, Extraction, Dissolution, And Voltammetry Of F-Species In A Room Temperature Ionic Liquid Solvent, Wendy Jacqueline Pemberton Aug 2011

Synthesis, Extraction, Dissolution, And Voltammetry Of F-Species In A Room Temperature Ionic Liquid Solvent, Wendy Jacqueline Pemberton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Room temperature ionic liquids (RTILs) are salts that are liquids from as low as -96 °C to up to 100 °C. RTILs are of high interest in many fields of study because of their negligible vapor pressure, high electrochemical stability, high conductivity, and wide electrochemical windows. These diverse solvents have recently been used in organic synthesis, as extraction solvents, and as electrochemical solvents. It is as a direct result of the multifunctional capabilities of these RTIL solvents that they are examined in this work. The ability to probe the chemistry of lanthanides and actinides is based on the unique properties …


Equilibrium Speciation Of Select Lanthanides In The Presence Of Acidic Ligands In Homo- And Heterogeneous Solutions, Troy Robinson Aug 2011

Equilibrium Speciation Of Select Lanthanides In The Presence Of Acidic Ligands In Homo- And Heterogeneous Solutions, Troy Robinson

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation explores lanthanide speciation in liquid solution systems related to separation schemes involving the acidic ligands: bis(2-ethylhexyl) phosphoric acid (HDEHP), lactate, and 8-hydroxyquinoline. Equilibrium speciation of neodymium (Nd3+ ), sodium (Na+ ), HDEHP, water, and lactate in the TALSPEAK liquid-liquid extraction system was explored under varied Nd3+ loading of HDEHP in the organic phase and through extraction from aqueous HCl and lactate media. System speciation was probed through vapor pressure osmometry, visible and Fourier Transform Infrared (FTIR) spectroscopy, 22 Na and 13 C labeled lactate radiotracer distribution measurements, Karl Fischer titrations, and equilibrium pH measurements. Distribution …


Unlv Stars Unabridged Report, University Of Nevada, Las Vegas Jun 2011

Unlv Stars Unabridged Report, University Of Nevada, Las Vegas

Reports (USI)

University of Nevada, Las Vegas, by earning a 2011 Silver Rating in the Sustainability Tracking, Assessment & Ratings System (STARS), is ahead of the curve among public universities – and improving.

STARS is a voluntary, self–reporting framework developed by the Association for the Advancement of Sustainability in Higher Education (AASHE) to help measure sustainability performance over time and among colleges and universities nationwide. The UNLV Sustainability Council oversaw STARS, which by measuring sustainability can help UNLV to reduce energy consumption and waste, improve education, attract research, and generate jobs.

A rating of Silver puts UNLV in great company – with …


Electrochemistry Of Technetium Analogues Rhenium And Molybdenum In Room Temperature Ionic Liquid, Pauline Nancy Serrano Jun 2011

Electrochemistry Of Technetium Analogues Rhenium And Molybdenum In Room Temperature Ionic Liquid, Pauline Nancy Serrano

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rhenium was used as an analog for Technetium to study the electrochemical redox properties because the two elements share the same stable oxidation states in aqueous solutions. However, Tc-99 is radioactive and is not readily available for experimentation purposes. Molybdenum is also of interest because when Mo-99 is irradiated, the decay products are Tc-99m and Tc-99. Approximately 30% Tc-99m is eluted from the Mo columns for radiopharmaceutical use with the remaining Mo-99 source decaying to Tc-99 which is discarded as radioactive hospital waste. Currently there are no viable procedures for the reclamation of the radioactive Tc-99 from either fission streams …


Extraction Chromatographic Studies Of Rutherfordium And Dubnium Homologs, Megan E. Bennett May 2011

Extraction Chromatographic Studies Of Rutherfordium And Dubnium Homologs, Megan E. Bennett

UNLV Theses, Dissertations, Professional Papers, and Capstones

Studying the chemistry of transactinide elements does not only allow for these elements to be properly placed in the Periodic Table, but it also permits for the extrapolation of the electronic structure based upon the position of the element in the Periodic Table. In addition it enable for the assessment of the role that relativistic effects play in the chemical behavior of the heaviest elements. An improved understanding of the role of relativistic effects in chemistry of the heaviest elements allows for a better understanding of the fundamentals principles that govern the Periodic Table. In order to investigate the chemistry …


Speciation And Spectroscopy Of The Uranyl And Tetravalent Plutonium Nitrate Systems: Fundamental Studies And Applications To Used Fuel Reprocessing, Nicholas A. Smith Dec 2010

Speciation And Spectroscopy Of The Uranyl And Tetravalent Plutonium Nitrate Systems: Fundamental Studies And Applications To Used Fuel Reprocessing, Nicholas A. Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation explores the use of UV-Visible spectroscopy and Time Resolved Laser Induced Fluorescence spectroscopy as near real time process monitors of uranium and plutonium concentrations in aqueous reprocessing trains. The molar absorptivities and linear ranges of these metals were investigated under total nitrate and acid concentrations similar to those found in current reprocessing systems. Concurrent to this, a new multiple wavelength monitor was derived that is capable of determining the total nitrate concentration spectroscopically. This method uses the uranium absorbance spectrum to calculate the nitrate concentration in solution. When used as part of an Advanced Safeguard suite, this technique …


Hrc Enews — 2010 Fall, Megan K. Svarz Oct 2010

Hrc Enews — 2010 Fall, Megan K. Svarz

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, and a "new faces" listing for new staff, affiliates, and researchers.


Undergraduate Research Opportunities Program 2010, University Of Nevada, Las Vegas Aug 2010

Undergraduate Research Opportunities Program 2010, University Of Nevada, Las Vegas

Undergraduate Research Opportunities Program (UROP)

The Undergraduate Research Opportunities Program (UROP) cultivates and supports research partnerships and invites undergraduates to work as the junior colleagues of faculty. The program offers the opportunity to work on cutting edge research—whether you join established research projects or pursue your own ideas. As participants, undergraduates engage in each phase of standard research activity: developing research plans, writing proposals, conducting research, analyzing data. and presenting research results in oral and written form. The projects take place over the summer, and research can be done in any academic department or interdisciplinary laboratory. Projects can last for an entire semester, and many …


Hrc Enews — 2010 Summer, Megan K. Svarz Jul 2010

Hrc Enews — 2010 Summer, Megan K. Svarz

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, and a "new faces" listing for new staff, affiliates, and researchers.


Characterization Of Plutonium Particles Originating From The Bomarc Accident -1960, Richard Charles Gostic May 2010

Characterization Of Plutonium Particles Originating From The Bomarc Accident -1960, Richard Charles Gostic

UNLV Theses, Dissertations, Professional Papers, and Capstones

Within the U.S. arsenal, 32 accidents with nuclear weapons were reported between 1950 and 1980. One of these accidents occurred at McGuire AFB in 1960. A BOMARC missile armed with a nuclear warhead caught on fire and as a result the warhead was destroyed. Sub-millimeter particles consisting of weapons grade plutonium (WGPu) produced by this accident were distributed around the site and remained in the environment for 47 years. Soil cores known to contain WGPu particles produced by this accident were obtained. The particles were localized and removed from the soil with the aid of high resolution computed tomography. The …


Preparation And Characterization Of Extraction Chromatography Resins Using N-Donor Extractants For Trivalent Actinide And Lanthanide Separations, Christopher L. Klug May 2010

Preparation And Characterization Of Extraction Chromatography Resins Using N-Donor Extractants For Trivalent Actinide And Lanthanide Separations, Christopher L. Klug

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actinide and lanthanide elements exist in the geosphere and biosphere due to both natural abundances and anthropogenic activities. The investigation of the presence and transport of actinides through the environment is of great scientific interest. In order to prepare environmental samples for precise measurements, the individual actinides must be separated from the chemically similar lanthanides, and from neighboring actinides. Existing extraction chromatography resins are either poorly suited for this separation, have bleeding problems, are not reusable, or fail the CHON principle. In an effort to resolve these issues, malonamides and N-donor extractants from the BTP and BTBP classes of solvent …


Hrc Enews — 2010 Spring, Megan K. Svarz Apr 2010

Hrc Enews — 2010 Spring, Megan K. Svarz

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, a "new faces" listing for new staff, affiliates, and researchers, and an "of interest" section.


Temporal And Spatial Variations In Freshwater 14C Reservoir Effects: Lake Mývatn, Northern Iceland, Philippa L. Ascough, G. T. Cook, M. J. Church, E. Dunbar, Á. Einarsson, Thomas H. Mcgovern, A. J. Dugmore, Sophia Perdikaris, H. Hastie, A. Friðriksson, H. Gestsdóttir Jan 2010

Temporal And Spatial Variations In Freshwater 14C Reservoir Effects: Lake Mývatn, Northern Iceland, Philippa L. Ascough, G. T. Cook, M. J. Church, E. Dunbar, Á. Einarsson, Thomas H. Mcgovern, A. J. Dugmore, Sophia Perdikaris, H. Hastie, A. Friðriksson, H. Gestsdóttir

School of Global Integrative Studies: Faculty Publications

Lake Mývatn is an interior highland lake in northern Iceland that forms a unique ecosystem of international scientific importance and is surrounded by a landscape rich in archaeological and paleoenvironmental sites. A significant freshwater reservoir effect (FRE) has been identified in carbon from the lake at some Viking (about AD 870–1000) archaeological sites in the wider region (Mývatnssveit). Previous accelerator mass spectrometry (AMS) measurements indicated this FRE was about 1500–1900 14C yr. Here, we present the results of a study using stable isotope and 14C measurements to quantify the Mývatn FRE for both the Viking and modern periods. …


Hrc Enews — 2010 Winter, Megan K. Svarz Jan 2010

Hrc Enews — 2010 Winter, Megan K. Svarz

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, a "new faces" listing for new staff, affiliates, and researchers, and an "on the move" section listing new developments.


Unlv Magazine, Matthew K. Jacobsen, Holly Ivy De Vore, Lisa Arth, Cate Weeks, Greg Lacour, Tony Allen, Afsha Bawany, Barbara Cloud, Gian Galassi, Phil Hagen, Karyn S. Hollingsworth, Michelle Mouton, Erin O'Donnell Oct 2009

Unlv Magazine, Matthew K. Jacobsen, Holly Ivy De Vore, Lisa Arth, Cate Weeks, Greg Lacour, Tony Allen, Afsha Bawany, Barbara Cloud, Gian Galassi, Phil Hagen, Karyn S. Hollingsworth, Michelle Mouton, Erin O'Donnell

UNLV Magazine

No abstract provided.


Undergraduate Research Opportunities Program, University Of Nevada Las Vegas, College Of Sciences Aug 2009

Undergraduate Research Opportunities Program, University Of Nevada Las Vegas, College Of Sciences

Undergraduate Research Opportunities Program (UROP)

No abstract provided.


Mnte-2-Pyp And Radiation In A Prostate Cancer Model: Implications For Radiotherapy, Adeola Y. Makinde Jun 2009

Mnte-2-Pyp And Radiation In A Prostate Cancer Model: Implications For Radiotherapy, Adeola Y. Makinde

Loma Linda University Electronic Theses, Dissertations & Projects

A major limitation of successful radiation therapy in cancer treatment is the increase in normal tissue damage as higher doses are used to achieve greater tumor destruction. Radiation dose optimization in cancer therapy requires achieving maximum tumor destruction with minimal damage to normal tissue Antioxidants have been shown to protect normal tissues against radiation damage, as radiation-induced tissue damage results predominantly from reactive oxygen species that directly damage cellular components. However, for effective use as normal tissue radioprotectants in radiotherapy, these antioxidants must not protect the tumors. Mn (III) tetrakis (N-ethylpyridinium-2-yl) porphyrin (MnTE-2-PyP) is a metalloporphyrin antioxidant that has been …


Evaluation Of Low-Temperature Fluoride Routes To Synthesize Actinide Nitrides And Oxide Solid Solutions, Gunanda Waduge Chinthaka Silva May 2009

Evaluation Of Low-Temperature Fluoride Routes To Synthesize Actinide Nitrides And Oxide Solid Solutions, Gunanda Waduge Chinthaka Silva

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actinide mononitrides have been considered as a possible nuclear fuel for the Generation-IV nuclear reactor systems. In the process of evaluating these actinide mononitrides as nuclear fuel, it is important to study different chemical and physical characteristics of these compounds. Synthesis of the materials is thus important. Carbothermic reduction is one of the techniques that have been used to synthesize actinide mononitrides. In this method, a mixture of actinide oxide such as UO 2 and excess carbon is heat treated at temperatures greater than 1700 °C under a nitrogen atmosphere. The technique is however not promising in synthesizing the actinide …