States

Agroterrorism: Options in Congress (open access)

Agroterrorism: Options in Congress

Although U.S. intelligence agencies have not identified any terrorist acts targeting agricultural production (i.e., agroterrorism) in the United States to date, the events of September 11, 2001 have awakened the nation to their possibility. Some experts estimate that a single agroterrorist attack using a highly contagious livestock disease could cost between $10 billion and $30 billion to the U.S. economy. This report examines the potential threats to America’s agriculture from a deliberate biological attack, describes the current defense structure and capabilities available to respond to agroterrorism, and analyzes current congressional proposals to address the threat of biological weapons to U.S. agriculture.
Date: December 19, 2001
Creator: Segarra, Alejandro E.
Object Type: Report
System: The UNT Digital Library
Comparison of IEC and IEEE Standards for Computer-Based Control Systems Important to Safety (open access)

Comparison of IEC and IEEE Standards for Computer-Based Control Systems Important to Safety

The collections of IEEE and 1EC standards have some overlap, but in many cases cover significantly different topics. For example, 1EEE standards go to great depth on environmental qualification of many specific types of components, while IEC covers the topic only at the general level. Conversely, certain IEC standards deal with specific instrumentation and control functions, a topic area where IEEE standards are largely mute. This paper studies two questions related to the above observations. Which standards in each body should be coordinated with each other? What opportunities exist for the two bodies to build on each other's standards to efficiently improve upon the coverage of their sets of standards? Poor coordination between the two sets of standards poses a problem for the developers of systems for plant upgrades. Developers must try to address both sets of standards to avail themselves of a sufficiently broad market. Additionally, the IEEE and IEC standards together form a more comprehensive set of guidance than either set alone. If the interfaces between the standard sets were smoother, plant staff and system designers would have a better set of tools to help in the design and specification of I and C upgrades. To understand the …
Date: December 19, 2001
Creator: Johnson, G.
Object Type: Report
System: The UNT Digital Library
Density functional theory study of nitrous oxide decomposition over Fe- and Co-ZSM-5 (open access)

Density functional theory study of nitrous oxide decomposition over Fe- and Co-ZSM-5

Iron- and cobalt-exchanged ZSM-5 are active catalysts for the dissociation of nitrous oxide. In this study, density functional theory was used to assess a possible reaction pathway for the catalytic dissociation of N2O. The active center was taken to be mononuclear [FeO]+ or [CoO]+, and the surrounding portion of the zeolite was represented by a 24-atom cluster. The first step of N2O decomposition involves the formation of [FeO2]+ or [CoO2]+ and the release of N2. The metal-oxo species produced in this step then reacts with N2O again, to release N2 and O2. The apparent activation energies for N2O dissociation in Fe-ZSM-5 and Co-ZSM-5 are 39.4 and 34.6 kcal/mol, respectively. The preexponential factor for the apparent first-order rate coefficient is estimated to be of the order 107 s-1 Pa-1. While the calculated activation energy for Fe-ZSM-5 is in good agreement with that measured experimentally, the value of the preexponential factor is an order of magnitude smaller than that observed . The calculated activation energy for Co-ZSM-5 is higher than that reported experimentally. However, consistent with experiment, the rate of N2O decomposition on Co-ZSM-5 is predicted to be significantly higher than that on Fe-ZSM-5.
Date: December 19, 2001
Creator: Ryder, Jason A.; Chakraborty, Arup K. & Bell, Alexis T.
Object Type: Article
System: The UNT Digital Library
Eigenfrequencies of vortex state excitations in magnetic submicron-size disks. (open access)

Eigenfrequencies of vortex state excitations in magnetic submicron-size disks.

None
Date: December 19, 2001
Creator: Guslienko, K. Y.; Ivanov, B. A.; Novosad, V.; Otani, Y.; Shima, H. & Fukamichi, K.
Object Type: Article
System: The UNT Digital Library
Expression profiling and comparative sequence derived insights into lipid metabolism (open access)

Expression profiling and comparative sequence derived insights into lipid metabolism

Expression profiling and genomic DNA sequence comparisons are increasingly being applied to the identification and analysis of the genes involved in lipid metabolism. Not only has genome-wide expression profiling aided in the identification of novel genes involved in important processes in lipid metabolism such as sterol efflux, but the utilization of information from these studies has added to our understanding of the regulation of pathways participating in the process. Coupled with these gene expression studies, cross species comparison, searching for sequences conserved through evolution, has proven to be a powerful tool to identify important non-coding regulatory sequences as well as the discovery of novel genes relevant to lipid biology. An example of the value of this approach was the recent chance discovery of a new apolipoprotein gene (apo AV) that has dramatic effects upon triglyceride metabolism in mice and humans.
Date: December 19, 2001
Creator: Callow, Matthew J. & Rubin, Edward M.
Object Type: Article
System: The UNT Digital Library
Future Accelerators, Muon Colliders, and Neutrino Factories (open access)

Future Accelerators, Muon Colliders, and Neutrino Factories

Particle physics is driven by five great topics. Neutrino oscillations and masses are now at the fore. The standard model with extensions to supersymmetry and a Higgs to generate mass explains much of the field. The origins of CP violation are not understood. The possibility of extra dimensions has raised tantalizing new questions. A fifth topic lurking in the background is the possibility of something totally different. Many of the questions raised by these topics require powerful new accelerators. It is not an overstatement to say that for some of the issues, the accelerator is almost the experiment. Indeed some of the questions require machines beyond our present capability. As this volume attests, there are parts of the particle physics program that have been significantly advanced without the use of accelerators such as the subject of neutrino oscillations and many aspects of the particle-cosmology interface. At this stage in the development of physics, both approaches are needed and important. This chapter first reviews the status of the great accelerator facilities now in operation or coming on within the decade. Next, midrange possibilities are discussed including linear colliders with the adjunct possibility of gamma-gamma colliders, muon colliders, with precursor neutrino factories, …
Date: December 19, 2001
Creator: Carrigan, Richard A., Jr.
Object Type: Article
System: The UNT Digital Library
Human Cloning (open access)

Human Cloning

This report provides information about the Human Cloning where a human embryo produced via cloning involves the process called somatic cell nuclear transfer. The nuclear of the egg is removed and replaced with a mature body cell.
Date: December 19, 2001
Creator: Johnson, Judith A.
Object Type: Report
System: The UNT Digital Library
INVENTORY ABSTRACTION (open access)

INVENTORY ABSTRACTION

The purpose of the inventory abstraction, which has been prepared in accordance with a technical work plan (CRWMS M&O 2000e for ICN 02 of the present analysis, and BSC 2001e for ICN 03 of the present analysis), is to: (1) Interpret the results of a series of relative dose calculations (CRWMS M&O 2000c, 2000f). (2) Recommend, including a basis thereof, a set of radionuclides that should be modeled in the Total System Performance Assessment in Support of the Site Recommendation (TSPA-SR) and the Total System Performance Assessment in Support of the Final Environmental Impact Statement (TSPA-FEIS). (3) Provide initial radionuclide inventories for the TSPA-SR and TSPA-FEIS models. (4) Answer the U.S. Nuclear Regulatory Commission (NRC)'s Issue Resolution Status Report ''Key Technical Issue: Container Life and Source Term'' (CLST IRSR) key technical issue (KTI): ''The rate at which radionuclides in SNF [spent nuclear fuel] are released from the EBS [engineered barrier system] through the oxidation and dissolution of spent fuel'' (NRC 1999, Subissue 3). The scope of the radionuclide screening analysis encompasses the period from 100 years to 10,000 years after the potential repository at Yucca Mountain is sealed for scenarios involving the breach of a waste package and subsequent degradation …
Date: December 19, 2001
Creator: Ragan, G.
Object Type: Report
System: The UNT Digital Library
Joining of melt-textured YBCO : a direct contact method. (open access)

Joining of melt-textured YBCO : a direct contact method.

We report a method for making weld joints, capable of transmitting high supercurrent densities, in bulk samples of melt textured YBCO. The joining procedure is carried out in a flowing atmosphere of O{sub 2} to eliminate problems associated with nitrogen gas, which can become trapped in the joint. No filler or fluxing material is used. The method can be used to join large areas (several cm{sup 2}) that are capable of transmitting supercurrent densities exceeding 10{sup 4} A/cm{sup 2}.
Date: December 19, 2001
Creator: Chen, L.; Claus, H.; Paulikas, A. P.; Zheng, H. & Veal, B. W.
Object Type: Article
System: The UNT Digital Library
Membership of the 107th Congress: A Profile (open access)

Membership of the 107th Congress: A Profile

None
Date: December 19, 2001
Creator: Amer, Mildred L.
Object Type: Report
System: The UNT Digital Library
National Monument Issues (open access)

National Monument Issues

None
Date: December 19, 2001
Creator: Hardy-Vincent, Carol
Object Type: Report
System: The UNT Digital Library
Nonhomologous Mechanisms of Repair of Chromosomal Breaks (open access)

Nonhomologous Mechanisms of Repair of Chromosomal Breaks

Discovered three new proteins involved in DNA damage assessment. Interestingly they are all proteins involved in recombination, but they have very different roles in that process and other proteins that might be expected to be equivalently involved are not. This is developing into a very significant area of research.
Date: December 19, 2001
Creator: Haber, J. E.
Object Type: Report
System: The UNT Digital Library
Novel features of Josephson flux-flow in Bi-2212 : contribution of in-plane dissipation, coherent response to mm-wave radiation, size effect. (open access)

Novel features of Josephson flux-flow in Bi-2212 : contribution of in-plane dissipation, coherent response to mm-wave radiation, size effect.

None
Date: December 19, 2001
Creator: Latyshev, Y. I.; Koshelev, A. E.; Pavlenko, V. N.; Gaifullin, M.; Yamashita, T. & Matusda, Y.
Object Type: Article
System: The UNT Digital Library
On the embrittlement of Zircaloy-4 under RIA-relevant conditions. (open access)

On the embrittlement of Zircaloy-4 under RIA-relevant conditions.

The extended use of Zircaloy cladding in light water reactors degrades its mechanical properties by a combination of irradiation embrittlement, coolant-side oxidation, hydrogen pickup, and hydride formation. The hydrides are usually concentrated in the form of a dense layer or rim near the cooler outer surface of the cladding. Utilizing plane-strain ring-stretch tests to approximate the loading path in a reactivity-initiated accident (RIA) transient, we examined the influence of a hydride rim on the fracture behavior of unirradiated Zircaloy-4 cladding at room temperature and 300 C. Failure is sensitive to hydride-rim thickness such that cladding tubes with a hydride-rim thickness >100 {micro}m ({approx}700 wppm total hydrogen) exhibit brittle behavior, while those with a thickness <90 {micro}m ({approx}600 wppm) remain ductile. The mechanism of failure is identified as strain-induced crack initiation within the hydride rim and failure within the uncracked ligament due to either a shear instability or damage-induced fracture. We also report some preliminary results of the uniaxial tensile behavior of low-Sn Zircaloy-4 cladding tubes in a cold-worked, stress-relieved condition in the transverse (hoop) direction at strain rates of 0.001/s and 0.2/s and temperatures of 26-400 C.
Date: December 19, 2001
Creator: Daum, R.S.; Majumdar, S.; Billone, M.C.; Bates, D.W.; Koss, D.A. & Motta, A.T.
Object Type: Article
System: The UNT Digital Library
Performance of Bare and Sol-Gel Coated DKDP Crystal Surfaces Exposed to Multiple 351-nm Laser Pulses in Vacuum and Air (open access)

Performance of Bare and Sol-Gel Coated DKDP Crystal Surfaces Exposed to Multiple 351-nm Laser Pulses in Vacuum and Air

We have investigated the surface degradation of bare and sol-gel coated deuterated potassium dihydrogen phosphate (DKDP) crystals when exposed to 351-nm laser pulses in atmospheric air and nitrogen and at pressures ranging from atmospheric down to 10{sup -5} Torr vacuum. Optical microscopy, surface topography, surface chemical analyses, 351-nm pumped photoemission maps, and photometry results have been used to characterize these samples. We report the occurrence of two potentially linked surface degradation phenomena: the development of increased photoemission and the development of unacceptable surface roughening in the region exposed to the beam in vacuum. We note no degradation for surfaces exposed in air or nitrogen at pressures exceeding 1 torr. Diamond-turned DKDP surfaces show a ubiquitous, low-intensity photoemission signature before exposure to any laser fluence. The observed reduction of this emission signal as a function of operating pressure and accumulated laser energy when crystals are exposed to 351-nm laser pulses in air can be correlated with the removal of surface carbon.
Date: December 19, 2001
Creator: Whitman, P. K.; Norton, M.; Nostrand, M.; Molander, W.; Nelson, A.; Engelhard, M. et al.
Object Type: Article
System: The UNT Digital Library
Remapping of the Wind Energy Resource in the Midwestern United States: Preprint (open access)

Remapping of the Wind Energy Resource in the Midwestern United States: Preprint

A recent increase in interest and development of wind energy in the Midwestern United States has focused the need for updating wind resource maps of this area. The wind resource assessment group at the National Renewable Energy Lab., a U.S. Department of Energy (DOE) laboratory, has produced updated high-resolution (1-km) wind resource maps for several states in this region. This abstract describes the computerized tools and methodology used by NREL to create the higher resolution maps.
Date: December 19, 2001
Creator: Schwartz, M. & Elliot, D.
Object Type: Article
System: The UNT Digital Library
Small Business Administration: Overview and Issues (open access)

Small Business Administration: Overview and Issues

None
Date: December 19, 2001
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Small Business Administration: Overview and Issues (open access)

Small Business Administration: Overview and Issues

None
Date: December 19, 2001
Creator: Mulock, Bruce K.
Object Type: Report
System: The UNT Digital Library
Synergistic Use of IEEE and IEC Nuclear Power Plant Standards (open access)

Synergistic Use of IEEE and IEC Nuclear Power Plant Standards

Many organizations worldwide develop standards that affect nuclear instrumentation and control (I and C). Two of the primary standards organizations are the US IEEE's Nuclear Power Engineering Committee (NPEC), and the IEC subcommittee on Reactor Instrumentation (SC45A). This paper surveys the contents of the two sets of standards. Opportunities for complementary use of IEEE and IEC standards are discussed. The collections of IEEE. and IEC standards have some overlap, but in many cases cover significantly different topics. For example, IEEE standards go to great depth on environmental qualification of many specific types of components, while IEC covers the topic only at the general level. Conversely, certain IEC standards deal with specific instrumentation and control functions, a topic area where IEEE standards are largely mute. This paper considers how the two sets of standards may be used in a complementary fashion to achieve broader topic coverage than is possible using only one or the other standard suite. To understand the similarities and differences between IEC and IEEE nuclear standards layer diagrams were developed for each set of standards. Another paper [Johnson, 2001] used the same layer diagrams to investigate where coordination between the two sets of standards is most critical.
Date: December 19, 2001
Creator: Johnson, G
Object Type: Report
System: The UNT Digital Library
TESTING OF BASELINE AND LAMINATED FILTER DISKS USING MST AND MMST WITH A PILOT SCALE ROTARY FILTER (open access)

TESTING OF BASELINE AND LAMINATED FILTER DISKS USING MST AND MMST WITH A PILOT SCALE ROTARY FILTER

Testing was completed to compare the filtration performance of modified monosodium titanate (mMST) with that of monosodium titanate (MST) with the rotary microfilter. In addition, the performance of the new laminated filter disk was compared to that of the original baseline welded filter disk. Results showed that flux rates for mMST exceeded that of MST with both the baseline and laminated filter disks in deployment concentrations of 0.2 g/L of mMST and 0.4 g/L of MST. The filtration rate of the mMST with the laminated filter disk exceeded that of the baseline filter disk. However, the baseline filter disk filtration rate for MST was greater than that of the laminated disk. The measured sample turbidity for all tests was 1.06 NTU or less. A contract was established with SpinTek Filtration{trademark} to operate a 3-disk pilot scale unit with prototypic filter disks and various feeds and two different filter disk membranes. SpinTek evaluated a set of the baseline 0.5 micron filter disks as well as a set of laminated filter disks using the same 0.5 micron filter disks. The membrane used for both disk sets was manufactured by the Pall Corporation (PMM 050). Each set of disks was run with monosodium …
Date: December 19, 2001
Creator: Herman, D.
Object Type: Report
System: The UNT Digital Library
Time-Resolved Spectroscopic Investigation of Emission Observed during Damage in the Bulk of DKDP Crystals (open access)

Time-Resolved Spectroscopic Investigation of Emission Observed during Damage in the Bulk of DKDP Crystals

We have investigated the flash of light that accompanies laser damage using time-resolved spectroscopy. Damage events were initiated in the bulk of both fused silica and DKDP crystals with 355-nm 3-ns pulsed radiation. Spectra from the accompanying flash were recorded in the 200-500 nm wavelength range with 5-ns temporal resolution. Ten ns following damage initiation, the spectra were found to be roughly blackbody with temperatures on the order of 5000 K to 7000 K, depending on the material studied and excitation energy used. The observed temperatures and cooling rates can be related to the size and electron density of the plasma ''fireball'' that initiates the damage event.
Date: December 19, 2001
Creator: Carr, C W; Radousky, H B; Staggs, M; Rubenchik, A M; Feit, M & Demos, S G
Object Type: Article
System: The UNT Digital Library
Ultra high-gradient energy loss by a pulsed electron beam in a plasma (open access)

Ultra high-gradient energy loss by a pulsed electron beam in a plasma

The plasma wake-field mechanism can be used to couple energy at a high rate from a bunched electron beam into a plasma wave. We will present results from the Fermilab A0 facility where a beam with an initial energy of 14 MeV passes through the plasma to emerge with a much broader energy spread, spanning from a low of 3 MeV to a high of over 20 MeV. Over the 8 cm length of the 10{sup 14} cm{sup -3} plasma, this implies a 140 MeV/m deceleration and 72 MeV/m acceleration gradient.
Date: December 19, 2001
Creator: al., Nikolai Barov et
Object Type: Article
System: The UNT Digital Library
Using Reactive Transport Modeling to Evaluate the Source Term at Yucca Mountain (open access)

Using Reactive Transport Modeling to Evaluate the Source Term at Yucca Mountain

The conventional approach of source-term evaluation for performance assessment of nuclear waste repositories uses speciation-solubility modeling tools and assumes pure phases of radioelements control their solubility. This assumption may not reflect reality, as most radioelements (except for U) may not form their own pure phases. As a result, solubility limits predicted using the conventional approach are several orders of magnitude higher then the concentrations of radioelements measured in spent fuel dissolution experiments. This paper presents the author's attempt of using a non-conventional approach to evaluate source term of radionuclide release for Yucca Mountain. Based on the general reactive-transport code AREST-CT, a model for spent fuel dissolution and secondary phase precipitation has been constructed. The model accounts for both equilibrium and kinetic reactions. Its predictions have been compared against laboratory experiments and natural analogues. It is found that without calibrations, the simulated results match laboratory and field observations very well in many aspects. More important is the fact that no contradictions between them have been found. This provides confidence in the predictive power of the model. Based on the concept of Np incorporated into uranyl minerals, the model not only predicts a lower Np source-term than that given by conventional Np …
Date: December 19, 2001
Creator: Chen, Y.
Object Type: Report
System: The UNT Digital Library
Advanced Reservoir Characterization and Evaluation of CO{sub 2} Gravity Drainage in the Naturally Fractured Spraberry Trend Area, Class III (open access)

Advanced Reservoir Characterization and Evaluation of CO{sub 2} Gravity Drainage in the Naturally Fractured Spraberry Trend Area, Class III

The goal of this project was to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in west Texas. This objective was accomplished through research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interactions in the reservoirs, (3) reservoir performance analysis, and (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. The four areas have been completed and reported in the previous annual reports. This report provides the results of the final year of the project including two SPE papers (SPE 71605 and SPE 71635) presented in the 2001 SPE Annual Meeting in New Orleans, two simulation works, analysis of logging observation wells (LOW) and progress of CO{sub 2} injection.
Date: November 19, 2001
Creator: Knight, Bill & Schechter, David S.
Object Type: Report
System: The UNT Digital Library