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REFINEMENT OF THE NEPHELINE DISCRIMINATOR: RESULTS OF A PHASE I STUDY (open access)

REFINEMENT OF THE NEPHELINE DISCRIMINATOR: RESULTS OF A PHASE I STUDY

The performance of a glass used for immobilization of high-level nuclear waste (HLW) is generally quantified by its resistance to chemical degradation, or durability. The durability of a HLW glass is dependent on its composition. If crystalline phases form within a glass during cooling, the composition of the residual glass network is altered, therefore affecting the durability of the glass. Crystallization of nepheline (NaAlSiO{sub 4}) has been shown to adversely impact the durability of HLW glasses since it removes glass forming species (in this case, Al and Si) from the glass network. The propensity for nepheline crystallization in a HLW glass increases with increasing concentrations of Al{sub 2}O{sub 3} and Na{sub 2}O in the glass. Nepheline crystallization is therefore of concern for processing of HLW at the Defense Waste Processing Facility (DWPF) since the sludge waste streams at the Savannah River Site (SRS) can contain high concentrations of Al{sub 2}O{sub 3} and Na{sub 2}O. Currently, a 'nepheline discriminator' is included as a process control constraint at the DWPF. The nepheline discriminator relates the concentrations of SiO{sub 2}, Na{sub 2}O and Al{sub 2}O{sub 3} (as weight percentages in glass) to a critical value of 0.62. The discriminator defines a boundary line …
Date: February 13, 2008
Creator: Fox, K; James Newell, J; Tommy Edwards, T; David Best, D; Irene Reamer, I & Phyllis Workman, P
Object Type: Report
System: The UNT Digital Library
Radionuclide Air Emission Report for 2007 (open access)

Radionuclide Air Emission Report for 2007

Berkeley Lab operates facilities where radionuclides are handled and stored. These facilities are subject to the U.S. Environmental Protection Agency (EPA) radioactive air emission regulations in Code of Federal Regulations (CFR) Title 40, Part 61, Subpart H (EPA 1989). The EPA regulates radionuclide emissions that may be released from stacks or vents on buildings where radionuclide production or use is authorized or that may be emitted as diffuse sources. In 2007, all Berkeley Lab sources were minor stack or building emissions sources of radionuclides (sources resulting in a potential dose of less than 0.1 mrem/yr [0.001 mSv/yr]), there were no diffuse emissions, and there were no unplanned emissions. Emissions from minor sources either were measured by sampling or monitoring or were calculated based on quantities received for use or produced during the year. Using measured and calculated emissions, and building-specific and common parameters, Laboratory personnel applied the EPA-approved computer code, CAP88-PC, Version 3.0, to calculate the effective dose equivalent to the maximally exposed individual (MEI). The effective dose equivalent from all sources at Berkeley Lab in 2007 is 1.2 x 10{sup -2} mrem/yr (1.2 x 10{sup -4} mSv/yr) to the MEI, well below the 10 mrem/yr (0.1 mSv/yr) EPA dose …
Date: June 13, 2008
Creator: Wahl, Linnea & Wahl, Linnea
Object Type: Report
System: The UNT Digital Library
Alpha(phi2) From a Time-Dependent Analysis of B0 -> (rhopi)0 Dalitz-plot (open access)

Alpha(phi2) From a Time-Dependent Analysis of B0 -> (rhopi)0 Dalitz-plot

The authors present results of time-dependent Dalitz plot analyses of B{sup 0} {yields} ({rho}{pi}){sup 0} and the corresponding constraints on the angle {alpha} or {phi}{sub 2} of the CKM unitarity triangle from the B factories.
Date: October 13, 2008
Creator: Mohanty, G & U., Warwick
Object Type: Article
System: The UNT Digital Library
2006 Los Alamos National Laboratory Annual Illness and Injury Surveillance Report (open access)

2006 Los Alamos National Laboratory Annual Illness and Injury Surveillance Report

The U.S. Department of Energy’s (DOE) commitment to assuring the health and safety of its workers includes the conduct of illness and injury surveillance activities that provide an early warning system to detect health problems among workers. The Illness and Injury Surveillance Program monitors illnesses and health conditions that result in an absence, occupational injuries and illnesses, and disabilities and deaths among current workers.
Date: June 13, 2008
Creator: United States. Department of Energy. Office of Health, Safety, and Security.
Object Type: Report
System: The UNT Digital Library
Interim Report on Fuel Cycle Neutronics Code Development. (open access)

Interim Report on Fuel Cycle Neutronics Code Development.

As part of the Global Nuclear Energy Partnership (GNEP), a fast reactor simulation program was launched in April 2007 to develop a suite of modern simulation tools specifically for the analysis and design of sodium cooled fast reactors. The general goal of the new suite of codes is to reduce the uncertainties and biases in the various areas of reactor design activities by enhanced prediction capabilities. Under this fast reactor simulation program, a high-fidelity deterministic neutron transport code named UNIC is being developed. The final objective is to produce an integrated, advanced neutronics code that allows the high fidelity description of a nuclear reactor and simplifies the multi-step design process by direct coupling with thermal-hydraulics and structural mechanics calculations. Currently there are three solvers for the neutron transport code incorporated in UNIC: PN2ND, SN2ND, and MOCFE. PN2ND is based on a second-order even-parity spherical harmonics discretization of the transport equation and its primary target area of use is the existing homogenization approaches that are prevalent in reactor physics. MOCFE is based upon the method of characteristics applied to an unstructured finite element mesh and its primary target area of use is the fine grained nature of the explicit geometrical problems …
Date: May 13, 2008
Creator: Rabiti, C; Smith, M. A.; Kaushik, D. & Yang, W. S.
Object Type: Report
System: The UNT Digital Library
Final Report- "An Algorithmic and Software Framework for Applied Partial Differential Equations (APDEC): A DOE SciDAC Integrated Software Infrastructure Center (ISIC) (open access)

Final Report- "An Algorithmic and Software Framework for Applied Partial Differential Equations (APDEC): A DOE SciDAC Integrated Software Infrastructure Center (ISIC)

All of the work conducted under the auspices of DE-FC02-01ER25473 was characterized by exceptionally close collaboration with researchers at the Lawrence Berkeley National Laboratory (LBNL). This included having one of my graduate students - Sarah Williams - spend the summer working with Dr. Ann Almgren a staff scientist in the Center for Computational Sciences and Engineering (CCSE) which is a part of the National Energy Research Supercomputer Center (NERSC) at LBNL. As a result of this visit Sarah decided to work on a problem suggested by Dr. John Bell the head of CCSE for her PhD thesis, which she finished in June 2007. Writing a PhD thesis while working at one of the University of California (UC) managed DOE laboratories is a long established tradition at the University of California and I have always encouraged my students to consider doing this. For example, in 2000 one of my graduate students - Matthew Williams - finished his PhD thesis while working with Dr. Douglas Kothe at the Los Alamos National Laboratory (LANL). Matt is now a staff scientist in the Diagnostic Applications Group in the Applied Physics Division at LANL. Another one of my graduate students - Christopher Algieri - who …
Date: May 13, 2008
Creator: Puckett, Elbridge Gerry
Object Type: Report
System: The UNT Digital Library
Magnetic Cluster States in Nanostructured Materials (open access)

Magnetic Cluster States in Nanostructured Materials

The goal of this work is to fabricate model nanomaterials with different types of disorder and use atomic-scale characterization and macroscopic magnetization measurements to understand better how specific types of disorder affects macroscopic magnetic behavior. This information can be used to produce magnetic nanomaterials with specific properties for applications such as permanent magnets, soft magnetic material for motors and biomedical applications.
Date: June 13, 2008
Creator: Leslie-Pelecky, Diandra
Object Type: Report
System: The UNT Digital Library
Hydrogen Storage in Nano-Phase Diamond at High Temperature and Its Release (open access)

Hydrogen Storage in Nano-Phase Diamond at High Temperature and Its Release

The objectives of this proposed research were: 91) Separation and storage of hydrogen on nanophase diamonds. It is expected that the produced hydrogen, which will be in a mixture, can be directed to a nanophase diamond system directly, which will not only store the hydrogen, but also separate it from the gas mixture, and (2) release of the stored hydrogen from the nanophase diamond.
Date: October 13, 2008
Creator: Ghosh, Tushar K
Object Type: Report
System: The UNT Digital Library
Support for the Core Research Activities and Studies of the Computer Science and Telecommunications Board (CSTB) (open access)

Support for the Core Research Activities and Studies of the Computer Science and Telecommunications Board (CSTB)

The Computer Science and Telecommunications Board of the National Research Council considers technical and policy issues pertaining to computer science (CS), telecommunications, and information technology (IT). The functions of the board include: (1) monitoring and promoting the health of the CS, IT, and telecommunications fields, including attention as appropriate to issues of human resources and funding levels and program structures for research; (2) initiating studies involving CS, IT, and telecommunications as critical resources and sources of national economic strength; (3) responding to requests from the government, non-profit organizations, and private industry for expert advice on CS, IT, and telecommunications issues; and to requests from the government for expert advice on computer and telecommunications systems planning, utilization, and modernization; (4) fostering interaction among CS, IT, and telecommunications researchers and practitioners, and with other disciplines; and providing a base of expertise in the National Research Council in the areas of CS, IT, and telecommunications. This award has supported the overall operation of CSTB. Reports resulting from the Board's efforts have been widely disseminated in both electronic and print form, and all CSTB reports are available at its World Wide Web home page at cstb.org. The following reports, resulting from projects that were …
Date: May 13, 2008
Creator: Eisenberg, Jon
Object Type: Report
System: The UNT Digital Library
Mechanisms of disease: epithelial-mesenchymal transition and back again: does cellular plasticity fuel neoplastic progression? (open access)

Mechanisms of disease: epithelial-mesenchymal transition and back again: does cellular plasticity fuel neoplastic progression?

Epithelial-mesenchymal transition (EMT) is a conversion that facilitates organ morphogenesis and tissue remodeling in physiological processes such as embryonic development and wound healing. A similar phenotypic conversion is also detected in fibrotic diseases and neoplasia, which is associated with disease progression. EMT in cancer epithelial cells often seems to be an incomplete and bi-directional process. In this Review, we discuss the phenomenon of EMT as it pertains to tumor development, focusing on exceptions to the commonly held rule that EMT promotes invasion and metastasis. We also highlight the role of the RAS-controlled signaling mediators, ERK1, ERK2 and PI3-kinase, as microenvironmental responsive regulators of EMT.
Date: February 13, 2008
Creator: Bissell, Mina J; Turley, Eva A.; Veiseh, Mandana; Radisky, Derek C. & Bissell, Mina J.
Object Type: Article
System: The UNT Digital Library
Hanford Site Environmental Surveillance Data Report for Calendar Year 2007 (open access)

Hanford Site Environmental Surveillance Data Report for Calendar Year 2007

Environmental surveillance on and around the Hanford Site, located in southeastern Washington State, is conducted by the Pacific Northwest National Laboratory, which is operated by Battelle for the U.S. Department of Energy. The environmental surveillance data collected for this report provide a historical record of radionuclide and radiation levels attributable to natural causes, worldwide fallout, and Hanford Site operations. Data were also collected to monitor several chemicals and metals in Columbia River water, sediment, and wildlife. These data are included in this appendix. This report is the first of two appendices that support "Hanford Site Environmental Report for Calendar Year 2007" (PNNL-17603), which describes the Hanford Site mission and activities, general environmental features, radiological and chemical releases from operations, status of compliance with environmental regulations, status of programs to accomplish compliance, Hanford Site cleanup and remediation efforts, and environmental monitoring activities and results.
Date: October 13, 2008
Creator: Bisping, Lynn E.
Object Type: Report
System: The UNT Digital Library
Mechanical Design of the LSST Camera (open access)

Mechanical Design of the LSST Camera

The LSST camera is a tightly packaged, hermetically-sealed system that is cantilevered into the main beam of the LSST telescope. It is comprised of three refractive lenses, on-board storage for five large filters, a high-precision shutter, and a cryostat that houses the 3.2 giga-pixel CCD focal plane along with its support electronics. The physically large optics and focal plane demand large structural elements to support them, but the overall size of the camera and its components must be minimized to reduce impact on the image stability. Also, focal plane and optics motions must be minimized to reduce systematic errors in image reconstruction. Design and analysis for the camera body and cryostat will be detailed.
Date: June 13, 2008
Creator: Nordby, Martin; Bowden, Gordon; Foss, Mike; Guiffre, Gary; Ku, John & Schindler, Rafe
Object Type: Article
System: The UNT Digital Library
Engineered Electrodes and Electrode-Organic Interfaces for High-Efficiency Organic Photovoltaics (open access)

Engineered Electrodes and Electrode-Organic Interfaces for High-Efficiency Organic Photovoltaics

Organic photovoltaic (OPV) cells offer the ultimate promise of low cost, readily manufacturable, and durable solar power. While recent advances have led to cells with impressive performance levels, OPV cells have yet to break the double-digit efficiency barrier. Further gains in efficiency and durability, to that competitive with high-performance inorganic photovoltaics will require breakthroughs in transparent electrode and interfacial materials science and engineering. This project involved an integrated basic research effort carried out by an experienced and highly collaborative interdisciplinary team to address in unconventional ways, critical electrode-interfacial issues underlying OPV performance--controlling band offsets between transparent electrodes and organics, addressing current loss/leakage problems at interfaces, enhancing adhesion, interfacial stability, and device durability while minimizing cost. It synergistically combined materials and interfacial reagent synthesis, nanostructural and photovoltaic characterization, and high level quantum theory. The research foci were: 1) understanding of/development of superior transparent electrode materials and materials morphologies--i.e., better matched electronically and chemically to organic active layers, 2) understanding-based development of inorganic interfacial current-collecting/charge-blocking layers, and 3) understanding-based development of self-assembled adhesion/current-collecting/charge-blocking/cross-linking layers for high-efficiency OPV interfaces. Pursing the goal of developing the fundamental scientific understanding needed to design, fabricate, prototype and ultimately test high-efficiency OPV cells incorporating these new concepts, …
Date: November 13, 2008
Creator: Marks, Tobin J.; Chang, R. P. H.; Mason, Tom; Poeppelmeier, Ken & Freeman, Arthur J.
Object Type: Report
System: The UNT Digital Library
Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials (open access)

Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials

Without quality historical records that provide the composition of legacy materials, the elemental and/or chemical characterization of such materials requires a manual analytical strategy that may expose the analyst to unknown toxicological hazards. In addition, much of the existing legacy inventory also incorporates radioactivity, and, although radiological composition may be determined by various nuclear-analytical methods, most importantly, gamma-spectroscopy, current methods of chemical characterization still require direct sample manipulation, thereby presenting special problems with broad implications for both the analyst and the environment. Alternately, prompt gamma activation analysis (PGAA) provides a'single-shot' in-situ, non-destructive method that provides a complete assay of all major entrained elemental constituents.1-3. Additionally, neutron activation analysis (NAA) using short-lived activation products complements PGAA and is especially useful when NAA activation surpasses the PGAA in elemental sensitivity.
Date: February 13, 2008
Creator: Firestone, Richard B; English, G. A.; Firestone, R. B.; Perry, D. L.; Reijonen, J. P.; Leung, Ka-Ngo et al.
Object Type: Article
System: The UNT Digital Library
DHS Regional Reachback: Rapid Expert Radiation Alarm Assistance. (open access)

DHS Regional Reachback: Rapid Expert Radiation Alarm Assistance.

Following assessments that attacks with radiological and nuclear weapons are possible, detection system deployments are being supported at national and local levels. Detection systems include both, highly sensitive but non-discriminating detectors, as well as detectors and algorithms capable of distinguishing and identifying gamma rays by energy. The latter systems, usually handheld systems based on sodium iodide detectors, also provide analysis of the specific radionuclides present and are referred to as radioisotope identifiers (RIIDs). Studies have shown that sodium iodide based RIIDs fall far short of 100% accurate identifications. The U.S. Department of Homeland Security (DHS) initiated the Regional Reachback (RRB) Program in 2006 to provide rapid expert interpretation of gamma spectroscopic data from radiation alarms from detection systems deployed by state and local authorities. With expert specialists on call 24/7, RRB provides an avenue for local and state authorities to verify routine results, interpret unknown identifications, and notify national response assets if needed. This paper will provide details of the RRE3 program, an outline of the analysis process, a description of the drills and training systems used to maintain specialists response performance, and examples of drills and incidents from the first full year of operation.
Date: July 13, 2008
Creator: Bowerman, B.; Archer, D.; Young, J.; Monetti, M. & Savage, B.
Object Type: Article
System: The UNT Digital Library
Lattice and Collective Effects for PEP-X (open access)

Lattice and Collective Effects for PEP-X

This is a more comprehensive report of the accelerator physics in the white paper 'PEP-X Light Source at SLAC'. A new light source called 'PEP-X' would reside in the 2.2-km PEP-II tunnel. It has a hybrid lattice where two of its six arcs contain DBA cells that provide a total of 30 straight sections for insertion device beam lines and the remaining arcs contain TME cells for an extremely low emittance. Using 90 meter damping wigglers the horizontal emittance at 4.5 GeV is further reduced to 0.1 nm-rad. Many collective effects including intra-beam scattering, Touschek lifetime, and fast ion instability are studied. We expect that PEP-X will produce photon beams having brightnesses near 10{sup 22} (ph/s/mm{sup 2}/mrad{sup 2}/0.1% BW) at 10 keV and 10{sup 21} at 35 keV.
Date: May 13, 2008
Creator: Bane, Karl; Cai, Yunhai; Chao, Alex; Hettel, Robert; Huang, Zhirong; Nosochkov, Yuri et al.
Object Type: Report
System: The UNT Digital Library
Chandra Reveals Twin X-ray Jets in the Powerful FR-II Radio Galaxy 3C353 (open access)

Chandra Reveals Twin X-ray Jets in the Powerful FR-II Radio Galaxy 3C353

We report X-ray imaging of the powerful FR II radio galaxy 3C 353 using the Chandra X-ray Observatory. 3C 353's two 4-inch wide and 2-feet long jets allow us to study in detail the internal structure of the large-scale relativistic outflows at both radio and X-ray photon energies with the sub-arcsecond spatial resolution provided by the VLA and Chandra instruments. In a 90 ks Chandra observation, we have detected X-ray emission from most radio structures in 3C 353, including the nucleus, the jet and the counterjet, the terminal jet regions (hotspots), and one radio lobe. We show that the detection of the X-ray emission associated with the radio knots and counterknots, which is most likely non-thermal in origin, puts several crucial constraints on the X-ray emission mechanisms in powerful large-scale jets of quasars and FR II sources. In particular, we show that this detection is inconsistent with the inverse-Compton model proposed in the literature, and instead implies a synchrotron origin of the X-ray jet photons. We also find that the width of the X-ray counterjet is possibly narrower than that measured in radio bands, that the radio-to-X-ray flux ratio decreases systematically downstream along the jets, and that there are substantial …
Date: June 13, 2008
Creator: Kataoka, J.; Stawarz, L.; Harris, D.E.; Siemiginowska, A.; Ostrowski, M.; Swain, M.R. et al.
Object Type: Article
System: The UNT Digital Library
Recent Developments in Impact and Application to Future Light Sources (open access)

Recent Developments in Impact and Application to Future Light Sources

This paper discusses two recently added capabilities of the IMPACT suite that are relevant to modeling electron linacs, namely the new 1D coherent synchrotron radiation (CSR) modeling capability and the integrated Green's function (IFG) algorithm for modeling high aspect ratio beams. In addition, we present initial results of application of the enhanced version of IMPACT-Z to high-fidelity modeling of the microbunching instability in a realistic light source lattice.
Date: February 13, 2008
Creator: Pogorelov, I.; Qiang, J.; Ryne, R.; Venturini, M.; Zholents, A. & Warnock, R.
Object Type: Article
System: The UNT Digital Library
Final Technical Report: The Effects of Iron Complexing Ligands on the Long Term Ecosystem Response to Iron Enrichment of HNLC waters (open access)

Final Technical Report: The Effects of Iron Complexing Ligands on the Long Term Ecosystem Response to Iron Enrichment of HNLC waters

Substantial increases in the concentrations of the stronger of two Fe(III) complexing organic ligand classes measured during the mesoscale Fe enrichment studies IronEx II and SOIREE appeared to sharply curtailed Fe availability to diatoms and thus limited the efficiency of carbon sequestration to the deep. Detailed observations during IronEx II (equatorial Pacific Ocean) and SOIREE (Southern Ocean –Pacific sector) indicate that the diatoms began re-experiencing Fe stress even though dissolved Fe concentrations remained elevated in the patch. This surprising outcome likely is related to the observed increased concentrations of strong Fe(III)-complexing ligands in seawater. Preliminary findings from other studies indicate that diatoms may not readily obtain Fe from these chemical species whereas Fe bound by strong ligands appears to support growth of cyanobacteria and nanoflagellates. The difficulty in assessing the likelihood of these changes with in-situ mesoscale experiments is the extended monitoring period needed to capture the long-term trajectory of the carbon cycle. A more detailed understanding of Fe complexing ligand effects on long-term ecosystem structure and carbon cycling is essential to ascertain not only the effect of Fe enrichment on short-term carbon sequestration in the oceans, but also the potential effect of Fe enrichment in modifying ecosystem structure and …
Date: June 13, 2008
Creator: Cochlan, William P.
Object Type: Report
System: The UNT Digital Library
Role of a Transcriptional Regulator in Programmed Cell Death and Plant Development (open access)

Role of a Transcriptional Regulator in Programmed Cell Death and Plant Development

The long-term goal of this research is to understand the role(s) and molecular mechanisms of programmed cell death (PCD) in the controlling plant growth, development and responses to biotic and abiotic stress. We developed a genetic selection scheme to identify A. thaliana FB1-resistant (fbr) mutants as a way to find genes involved in PCD (Stone et al., 2000; Stone et al., 2005; Khan and Stone, 2008). The disrupted gene in fbr6 (AtSPL14) responsible for the FB1-insensitivity and plant architecture phenotypes encodes a plant-specific SBP DNA-binding domain transcriptional regulator (Stone et al., 2005; Liang et al., 2008). This research plan is designed to fill gaps in the knowledge about the role of SPL14 in plant growth and development. The work is being guided by three objectives aimed at determining the pathways in which SPL14 functions to modulate PCD and/or plant development: (1) determine how SPL14 functions in plant development, (2) identify target genes that are directly regulated by SPL14, and (3) identify SPL14 modifications and interacting proteins. We made significant progress during the funding period. Briefly, some major accomplishments are highlighted below: (1) To identify potential AtSPL14 target genes, we identified a consensus DNA binding site for the AtSPL14 SBP DNA-binding …
Date: September 13, 2008
Creator: Stone, Julie M.
Object Type: Report
System: The UNT Digital Library
Thermal-chemical-mechanical feedback during fluid-rock interactions: Implications for chemical transport and scales of equilibria in the crust (open access)

Thermal-chemical-mechanical feedback during fluid-rock interactions: Implications for chemical transport and scales of equilibria in the crust

Our research evaluates the hypothesis that feedback amongst thermal-chemical-mechanical processes operative in fluid-rock systems alters the fluid flow dynamics of the system which, in turn, affects chemical transport and temporal and spatial scales of equilibria, thus impacting the resultant mineral textural development of rocks. Our methods include computational experimentation and detailed analyses of fluid-infiltrated rocks from well-characterized terranes. This work focuses on metamorphic rocks and hydrothermal systems where minerals and their textures are utilized to evaluate pressure (P), temperature (T), and time (t) paths in the evolution of mountain belts and ore deposits, and to interpret tectonic events and the timing of these events. Our work on coupled processes also extends to other areas where subsurface flow and transport in porous media have consequences such as oil and gas movement, geothermal system development, transport of contaminants, nuclear waste disposal, and other systems rich in fluid-rock reactions. Fluid-rock systems are widespread in the geologic record. Correctly deciphering the products resulting from such systems is important to interpreting a number of geologic phenomena. These systems are characterized by complex interactions involving time-dependent, non-linear processes in heterogeneous materials. While many of these interactions have been studied in isolation, they are more appropriately analyzed …
Date: August 13, 2008
Creator: Dutrow, Barbara
Object Type: Report
System: The UNT Digital Library
Hanford Site Near-Facility Environmental Monitoring Data Report for Calendar Year 2007- Appendix 2 (open access)

Hanford Site Near-Facility Environmental Monitoring Data Report for Calendar Year 2007- Appendix 2

Near-facility environmental monitoring is defined as monitoring near facilities that have the potential to discharge or have discharged, stored, or disposed of radioactive or hazardous materials. Monitoring locations are associated with nuclear facilities such as the Plutonium Finishing Plant (PFP), Canister Storage Building (CSB), and the K Basins; inactive nuclear facilities such as N Reactor and the Plutonium-Uranium Extraction (PUREX) Facility; and waste storage or disposal facilities such as burial grounds, cribs, ditches, ponds, tank farms, and trenches. Much of the monitoring consists of collecting and analyzing environmental samples and methodically surveying areas near facilities. The program is also designed to evaluate acquired analytical data, determine the effectiveness of facility effluent monitoring and controls, assess the adequacy of containment at waste disposal units, and detect and monitor unusual conditions.
Date: October 13, 2008
Creator: Perkins, Craig J.; Dorsey, Michael; Mckinney, Stephen M.; Wilde, Justin W. & Duncan, Joanne P.
Object Type: Report
System: The UNT Digital Library
MAXI and GLAST Studies of Jets in Active Galaxies (open access)

MAXI and GLAST Studies of Jets in Active Galaxies

The recent launch of GLAST--coinciding with the MAXI workshop--opens a new era for studies of jet-dominated active galaxies, known as blazars. While the emission processes operating in various spectral bands in blazars are reasonably well understood, the knowledge of the details of the structure of the jet, location of the dissipation region with respect to the accreting black hole, and coupling of the jet to the accretion process are known only at a rudimentary level. Blazars are variable, and this provides an opportunity to use the variability in various bands--and in particular, the relationship of respective time series to each other--to explore the relative location of regions responsible for emission in the respective bands. Observationally, this requires well-sampled time series in as many spectral bands as possible. To this end, with its all-sky, sensitive monitoring capability, the recently launched GLAST, and MAXI, to be deployed in 2009, are the most promising instruments bound to provide good sampling in respectively the energetic gamma-ray, and the soft X-ray band. This paper highlights the inferences regarding blazar jets that can be gleaned from such joint observations.
Date: October 13, 2008
Creator: Madejski, Greg; Kataoka, Jun & Sikora, Marek
Object Type: Article
System: The UNT Digital Library
Office of Educational Programs, 2008 Summer Internship Symposium and Poster Session (open access)

Office of Educational Programs, 2008 Summer Internship Symposium and Poster Session

None
Date: August 13, 2008
Creator: White,K.; Morris, M.; Osiecki, C. & Blackburn, N.
Object Type: Article
System: The UNT Digital Library