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Localized or Systemic {italic In Vivo} Heat-Inactivation of Human Immunodeficiency Virus (HIV): A Mathematical Analysis (open access)

Localized or Systemic {italic In Vivo} Heat-Inactivation of Human Immunodeficiency Virus (HIV): A Mathematical Analysis

Temperatures as low as 42 C, maintained for a little as 25 minutes, inactivate {approx}25% of HIV. Furthermore, human immunodeficiency virus (HIV)-infected T-cells are more sensitive to heat than healthy lymphocytes and susceptibility increases when the cells are pre-sensitized by exposure to tumor necrosis factor. Thus, induction of a whole-body hyperthermia, or hyperthermia specifically limited to tissues having a high viral load, are potential antiviral therapies for acquired immunodeficiency disease (AIDS). Accordingly, we incorporated therapeutic hyperthermia into an existing mathematical model which evaluates the interaction between HIV and CD4{sup +} T cells. Given the assumptions and limitations of this model, the results indicate that a daily therapy, reducing the population of actively infected cells by 40% or infectious virus by 50%, would effectively reverse the depletion of T cells. In contrast, a daily reduction of 20% of either actively infected cells or infectious virus would have a marginal effect. However, reduction by 20% of both actively infected cells and infectious virus could restore T cell numbers, assuming that permanent damage had not been inflicted on the thymus. Whole-body hyperthermia seems unlikely to be clinically useful, unless it can be induced non-invasively without general anesthesia. In contrast, heating directed specifically to …
Date: December 15, 1993
Creator: Pennypacker, Carl R.; Perelson, A.S.; Nys, N.; Nelson, G. & Sessler, D.I.
System: The UNT Digital Library
[InHouse, Vol. 3 No. 2] (open access)

[InHouse, Vol. 3 No. 2]

A clipping from the UNT publication InHouse that covers fundraising for UNT programs. The two main articles deal with funding by the J. Paul Getty Trust and individuals for the NTIEVA program and also Wal-Mart's funding for a scholarship for students.
Date: December 1993
Creator: Lane, Dr. Peter B.
System: The UNT Digital Library
Strongly coupled ionic mixtures and the H/He EOS (open access)

Strongly coupled ionic mixtures and the H/He EOS

This paper summarizes recent work on the strongly coupled OCP and Binary Ionic Mixture equation of state and other thermodynamic quantities in white dwarf interior conditions for both fluid and solid phases with the assumption of a uniform background. Conditions for phase separation of different elements in fluid or solid phases is strongly dependent on deviations from the linear mixing rule which gives the equation of state as an additive function of the OCP equation of state. These deviations turn out to be small (a few parts in 10{sup 5}) and always positive including the case where the fraction of the higher Z component approaches 0. Also the equation of state of strongly coupled light elements (H and He particularly) obtained from simulations with a linear response description of the electrons is given for conditions appropriate to brown dwarf star interiors. Recent Livermore work on a band structure calculation of the enthalpy of H and He mixtures under jovian conditions is discussed. This work leads to a prediction of a high temperature (15,000 K) for miscibility of He in ionized H at 10 Mb.
Date: December 2, 1993
Creator: DeWitt, H. E.
System: The UNT Digital Library
Rf modeling and design of a folded waveguide launcher for the Alcator C-Mod tokamak (open access)

Rf modeling and design of a folded waveguide launcher for the Alcator C-Mod tokamak

The folded waveguide (FWG) launcher is being investigated as an improved antenna configuration for plasma heating in the ion cyclotron range of frequencies (ICRF). A development FWG launcher was successfully tested at Oak Ridge National Laboratory (ORNL) with a low-density plasma load and found to have significantly greater power density capability than current strap-type antennas operating in similar plasmas. To further test the concept on a high density tokamak plasma, a collaboration has been set up between ORNL and Massachusetts Institute of Technology (MIT) to develop and test an 80-MHz, 2-MW FWG on the Alcator C-Mod tokamak at MIT. The radio frequency (rf) electromagnetic modeling techniques and laboratory measurements used in the design of this antenna are described in this paper. A companion paper describes the mechanical design of the FWG.
Date: December 1, 1993
Creator: Bigelow, T. S.; Fogelman, C. F.; Baity, F. W.; Carter, M. D.; Hoffman, D. J.; Ryan, P. M. et al.
System: The UNT Digital Library
Phase-sensitive flow cytometry: New technology for analyzing biochemical, functional, and structural features in fluorochrome- labeled cells/particles (open access)

Phase-sensitive flow cytometry: New technology for analyzing biochemical, functional, and structural features in fluorochrome- labeled cells/particles

Flow cytometry (FCM) instruments rapidly measure biochemical, functional, and cytological properties of individual cells and macromolecular components, e.g., chromosomes, for clinical diagnostic medicine and biomedical and envirorunental research applications. These measurements are based on labeling cells with multiple fluorochromes for correlated analysis of macromolecules, such as DNA RNA, protein, and cell-surface receptors. This report describes the development of a phase-sensitive flow cytometer that provides unique capabilities for making laser-excited, phase-resolved measurements on fluorochrome-labelled cells and particles.
Date: December 1, 1993
Creator: Steinkamp, J. A.
System: The UNT Digital Library
Logistics for the implementation of lead-free solders on electronic assemblies (open access)

Logistics for the implementation of lead-free solders on electronic assemblies

The prospects of legislative and regulatory action aimed at taxing, restricting or banning lead-bearing materials from manufactured products has prompted the electronics community to examine the implementation of lead-free solders to replace currently used lead-containing alloys in the manufacture of electronic devices and assemblies. The logistics for changing the well established ``tin-lead solder technology`` require not only the selection of new compositions but also the qualification of different surface finishes and manufacturing processes. The meniscometer/wetting balance technique was used to evaluate the wettability of several candidate lead-free solders as well as to establish windows on processing parameters so as to facilitate prototype manufacturing. Electroplated and electroless 100Sn coatings, as well as organic preservatives, were also examined as potential alternative finishes for device leads and terminations as well as circuit board conductor surfaces to replace traditional tin-lead layers. Sandia National Laboratories and AT&T have implemented a program to qualify the manufacturing feasibility of surface mount prototype circuit boards using several commercial lead-free solders by infrared reflow technology.
Date: December 31, 1993
Creator: Vianco, P. T. & Artaki, I.
System: The UNT Digital Library
Measurement of the W mass in the D0 detector (open access)

Measurement of the W mass in the D0 detector

We report the results of a preliminary analysis of the W {r_arrow} e{nu} decays observed in 14 pb{sup {minus}1} of data taken during the Fermilab Tevatron Run l(a). After normalizing the mass scale to the Z mass measured at LEP, we find a value for the W mass of 79.86 {plus_minus} 0.16(stat) {plus_minus} 0.20(syst) {plus_minus} 0.31(scale) GeV. The method for extracting the W mass and the details of the error analysis are presented and discusses.
Date: December 1, 1993
Creator: Zhu, Qiang
System: The UNT Digital Library
Nuclear disarmament verification (open access)

Nuclear disarmament verification

Arms control treaties, unilateral actions, and cooperative activities -- reflecting the defusing of East-West tensions -- are causing nuclear weapons to be disarmed and dismantled worldwide. In order to provide for future reductions and to build confidence in the permanency of this disarmament, verification procedures and technologies would play an important role. This paper outlines arms-control objectives, treaty organization, and actions that could be undertaken. For the purposes of this Workshop on Verification, nuclear disarmament has been divided into five topical subareas: Converting nuclear-weapons production complexes, Eliminating and monitoring nuclear-weapons delivery systems, Disabling and destroying nuclear warheads, Demilitarizing or non-military utilization of special nuclear materials, and Inhibiting nuclear arms in non-nuclear-weapons states. This paper concludes with an overview of potential methods for verification.
Date: December 31, 1993
Creator: DeVolpi, A.
System: The UNT Digital Library
Thermal treatment of high explosives at Mason & Hanger/Pantex Plant (open access)

Thermal treatment of high explosives at Mason & Hanger/Pantex Plant

The Pantex plant presently processes about 45,000 kg (100,000 lb) of high explosives annually by outdoor burning. About half of the explosives are weapon components weighing over 5 kg (10 lb) which come directly out of nuclear weapons being removed from the stockpile. The other half is generated from various support processes, special tests, etc. Burning serves the three-fold purpose of demilitarizing, removing all classified characteristics, and eliminating the severe hazard posed by the explosives themselves. Transporting such large quantities of classified high explosives for such processing at another site would be prohibitive. Computerized atmospheric modelling of the burning process was conducted during the past year. The results were somewhat surprising in that oxides of nitrogen and carbon monoxide, two ``criteria pollutants,`` were not of great concern even though it is known that high explosives contain significant amounts of nitrogen and they generate measureable amounts of carbon monoxide when they are burned. Rather, it was determined that hydrogen fluoride gas is of much greater concern, and stringent controls on the burning operation have been implemented to address this concern. Although the amount of fluorine-containing explosive must be restricted, other kinds of air emissions are not a great concern. This favorable …
Date: December 31, 1993
Creator: Patterson, W. E. & Phelan, P. F.
System: The UNT Digital Library
A comparison of the evolution of cold and hot deformation microstructures and textures in fcc metals (open access)

A comparison of the evolution of cold and hot deformation microstructures and textures in fcc metals

Microstructures and textures which develop during cold deformation are compared to those which develop during hot deformation. This comparison is made using the evolutionary framework of grain subdivision and the formation of low energy dislocation structures. During deformation grains are subdivided into differently deforming regions separated by geometrically necessary dislocation boundaries. These boundaries include dense dislocation walls, microbands, lamellar boundaries and subgrains. Grain subdivision occurs as a result of the requirement for strain accommodation balanced by energy considerations. This grain subdivision weakens the texture and increases the texture scatter. The tendency for grain subdivision decreases with increasing temperature of deformation with implications for the microstructural evolution and the texture formation.
Date: December 31, 1993
Creator: Hughes, D. A. & Hansen, N.
System: The UNT Digital Library
Solar neutrino experiments: An update (open access)

Solar neutrino experiments: An update

The situation in solar neutrino physics has changed drastically in the past few years, so that now there are four neutrino experiments in operation, using different methods to look at different regions of the solar neutrino energy spectrum. These experiments are the radiochemical {sup 37}Cl Homestake detector, the realtime Kamiokande detector, and the different forms of radiochemical {sup 71}Ga detectors used in the GALLEX and SAGE projects. It is noteworthy that all of these experiments report a deficit of observed neutrinos relative to the predictions of standard solar models (although in the case of the gallium detectors, the statistical errors are still relatively large). This paper reviews the basic principles of operation of these neutrino detectors, reports their latest results and discusses some theoretical interpretations. The progress of three realtime neutrino detectors that are currently under construction, SuperKamiok, SNO and Borexino, is also discussed.
Date: December 31, 1993
Creator: Hahn, R. L.
System: The UNT Digital Library
A 12-channel VMEbus-based pulse-height analysis module (open access)

A 12-channel VMEbus-based pulse-height analysis module

The author describes a 12-channel VMEbus-based pulse-height analysis board that was designed for use in a high-rate, multidetector, gamma-ray imaging system. This module was designed to minimize dead-time losses and to allow all key parameters to be software controlled. Gamma-ray detectors are connected directly to this module, eliminating the need for additional electronics.
Date: December 1, 1993
Creator: Arnone, G. J.
System: The UNT Digital Library
Case studies of corrosion of mixed waste and transuranic waste drums (open access)

Case studies of corrosion of mixed waste and transuranic waste drums

This paper presents three case studies of corrosion of waste drums at the Los Alamos National Laboratory (LANL). Corrosion was not anticipated by the waste generators, but occurred because of subtle chemical or physical mechanisms. In one case, drums of a cemented transuranic (TRU) sludge experienced general and pitting corrosion. In the second instance, a chemical from a commercial paint stripper migrated from its primary containment drums to chemically attack overpack drums made of mild carbon steel. In the third case, drums of mixed low level waste (MLLW) soil corroded drum packaging even though the waste appeared to be dry when it was placed in the drums. These case studies are jointly discussed as ``lessons learned`` to enhance awareness of subtle mechanisms that can contribute to the corrosion of radioactive waste drums during interim storage.
Date: December 1, 1993
Creator: Kosiewicz, S. T.
System: The UNT Digital Library
Consolidated incineration facility technical support (open access)

Consolidated incineration facility technical support

In 1996, the Savannah River Site plans to begin operation of the Consolidated Incineration Facility (CIF) to treat solid and liquid RCRA hazardous and mixed wastes. The Savannah River Technology Center (SRTC) leads an extensive technical support program designed to obtain incinerator and air pollution control equipment performance data to support facility start-up and operation. Key components of this technical support program include recently completed waste burn tests at both EPA`s Incineration Research Facility and at Energy and Environmental Research Corporation`s Solid Waste Incineration Test Facility. The main objectives for these tests were determining the fate of heavy metals, measuring organics destruction and removal efficiencies, and quantifying incinerator offgas particulate loading and size distribution as a function of waste feed characteristics and incineration conditions. In addition to these waste burning tests, the SRTC has recently completed installations of the Offgas Components Test Facility (OCTF), a 1/10 scale CIF offgas system pilot plant. This pilot facility will be used to demonstrate system operability and maintainability, evaluate and optimize equipment and instrument performance, and provide direct CIF start-up support. Technical support programs of this type are needed to resolve technical issues related with treatment and disposal of combustible hazardous, mixed, and low-level …
Date: December 31, 1993
Creator: Burns, D. & Looper, M. G.
System: The UNT Digital Library
Inorganic polymer-derived ceramic membranes (open access)

Inorganic polymer-derived ceramic membranes

Polymeric silica sols were used to prepare membranes on commercial {gamma}-A1{sub 2}O{sub 3} supports. Aging of the silica sols was shown to be effective to form discrete membrane layers. He/N{sub 2} selectivity factors exceeding ideal Knudsen values were observed when the sols were prepared under conditions in which the condensation rate was minimized. It is proposed that the average pore size of the membrane depends on the balance of capillary pressure and modulus during membrane deposition and that the breadth of the pore size distribution might be influenced by the extent of condensation accompanying membrane deposition. The use of organic templates may allow independent control of pore size, pore shape, and pore volume. The membranes are to be used in processing natural gas (gas separation/purification).
Date: December 31, 1993
Creator: Brinker, C. J.; Sehgal, R.; Raman, N.; Schunk, P. R. & Headley, T. J.
System: The UNT Digital Library
Design optimization analysis of the new SPR III-M reactor (open access)

Design optimization analysis of the new SPR III-M reactor

This report discusses the finite element method analysis which was used to refine the SPR III-M reactor fuel assembly mechanical design to withstand the stresses and strains of pulse-mode operation, which induces thermal shock loading in the fuel assembly components. The original reactor design was analyzed for its structural response to separate pulses at increasingly severe levels. Subsequent calculations at one consistent pulse level examined several design modifications, which will result in a significant reduction in stress in the final design.
Date: December 31, 1993
Creator: Miller, J. D.
System: The UNT Digital Library
Review of lithium-ion technology (open access)

Review of lithium-ion technology

The first practical use of graphite intercalation compounds (GIC) as battery anodes was reported in a 1981 patent by Basu in which a molten salt cell was described having a negative electrode that consisted of lithium intercalated in graphite. A second patent by Basu, issued in 1983, described an ambient temperature rechargeable system which also utilized lithium intercalated in graphite as the anode. Work in this area progressed at a low level, however, until interest was sparked in 1990 when Sony Corporation announced a new ``lithium-ion`` rechargeable cell containing a lithium ion intercalating carbon anode. These cells have the advantages of metallic lithium systems; i.e., high energy density, high voltage, and light weight, without the disadvantages of dendrite formation on charge and the safety considerations associated with metallic lithium. Materials other than carbon have been studied as intercalation anodes. Examples are Fe{sub 2}O{sub 3}, WO{sub 2} and TiS{sub 2}. Although these alternate anode materials are of interest academically and for specialty applications, they do not hold much promise for widespread general use due to their increased weight and lower cell voltage. Studies of cathode materials for lithium-ion systems have centered on the transition metal chalcogenides. A number of these materials …
Date: December 31, 1993
Creator: Levy, S. C. & Cieslak, W. R.
System: The UNT Digital Library
Moderator materials and neutronic performance (open access)

Moderator materials and neutronic performance

The great variety of instruments proposed for LANSCE-II entails an equally varied set of requirements for the target stations moderators. Besides the obvious features such as intensity and pulse width of the neutron pulse, a number of more pragmatic questions have to be addressed such as fast neutron background and energy deposition in the moderators, especially at large proton beam powers such as the 1 MW proton beam power proposed for LANSCE-II.
Date: December 31, 1993
Creator: Daemen, L. L.; Russell, G. J.; Pitcher, E. J. & Lujan, M. Jr.
System: The UNT Digital Library
Collapse of Flux Tubes (open access)

Collapse of Flux Tubes

Flux tubes are one of the most elementary systems of quantum chromodynamics. They are the idealized configurations of heavy quark-antiquark pairs at large separations L such that the region between can be assumed to possess axial-cylindrical symmetry. They play a central role in lattice QCD calculations and in models of QCD, as well as in the phenomenology of QCD processes. Lattice QCD calculations on flux tubes are generally limited to the quenched approximation (no massless quarks) and allow for a separation of the heavy quark-antiquark of only about 1 fm. Static flux tubes are unstable at separations greater than 1 fm, since the energy required to stretch the tube by 1 fm is about 1 GeV and that is about the energy difference between a quarkonium, Q{bar Q}, and a pair of heavy-light mesons, Q{bar q} + {bar Q}q. Lattice calculations without light quarks cannot explore this instability. The author then reviews work on efforts to explore the creation of light quark pairs as a mechanism for flux tube breaking.
Date: December 31, 1993
Creator: Wilets, L.
System: The UNT Digital Library
X-ray production with sub-picosecond laser pulses (open access)

X-ray production with sub-picosecond laser pulses

The interaction of intense, sub-picosecond laser pulses with solid targets produces intense picosecond x-ray pulses. With focused laser pulses of several 10 {sup 18} W/cm{sup 2}, He-like and H-like line radiation from targets such as aluminum and silicon has been produced. The energy conversion efficiency from the laser pulse energy to the 1--2 keV line x-rays is nearly one percent. The duration of the line x-ray radiation is of the order of ten picoseconds, although this may be an upper estimate because of the temporal resolution of the x-ray streak camera. The spatial extent of the x-ray source region is only slightly larger than the laser focal spot, or about 10 {mu}m in diameter. With these characteristics, such x-ray sources emit an intensity of nearly 10{sup 14} W/cm{sup 2}. Experiments and modeling which led to the above conclusions will be discussed.
Date: December 31, 1993
Creator: Schappert, G. T.; Cobble, J. A.; Fulton, R. D. & Kyrala, G. A.
System: The UNT Digital Library
Performance assessment of the Greater Confinement Disposal facility on the Nevada Test Site: Comparing the performance of two conceptual site models (open access)

Performance assessment of the Greater Confinement Disposal facility on the Nevada Test Site: Comparing the performance of two conceptual site models

A small amount of transuranic (TRU) waste has been disposed of at the Greater Confinement Disposal (GCD) site located on the Nevada Test Site`s (NTS) Radioactive Waste Management Site (RWMS). The waste has been buried in several deep (37 m) boreholes dug into the floor of an alluvial basin. For the waste to remain in its current configuration, the DOE must demonstrate compliance of the site with the TRU disposal requirements, 40 CFR 191. Sandia`s approach to process modelling in performance assessment is to use demonstrably conservative models of the site. Choosing the most conservative model, however, can be uncertain. As an example, diffusion of contaminants upward from the buried waste in the vadose zone water is the primary mechanism of release. This process can be modelled as straight upward planar diffusion or as spherical diffusion in all directions. The former has high fluxes but low release areas, the latter has lower fluxes but is spread over a greater area. We have developed analytic solutions to a simple test problem for both models and compared the total integrated discharges. The spherical diffusion conceptual model results in at least five times greater release to the accessible environment than the planar model …
Date: December 31, 1993
Creator: Baer, T. A.; Price, L. L. & Gallegos, D. P.
System: The UNT Digital Library
Hyperon polarization and magnetic moments (open access)

Hyperon polarization and magnetic moments

Inclusively produced hyperons with significant polarization were first observed at Fermilab about seventeen years ago. This and subsequent experiments showed that {Lambda}{degree} were produced polarized while {bar {Lambda}}{degree} had no polarization in the same kinematical region. This set the stage for many experiments which showed that most hyperons are produced polarized. Recent Fermilab experiments have showed that this phenomena is even more complex and theoretical understanding is still lacking. Nevertheless polarized hyperon beams have been an extremely useful experimental tool in measuring hyperon magnetic moments. Recently, magnetic moment precession of channeled particles in bent crystals has been observed. This opens the possibility of measuring the magnetic moments of charmed baryons.
Date: December 1, 1993
Creator: Lach, J.
System: The UNT Digital Library
Some considerations on robotics for environmental friendliness (open access)

Some considerations on robotics for environmental friendliness

This paper presents a series of considerations regarding the use and potential of robotic devices for supporting humans in a variety of tasks, while maintaining, if not improving, environmental friendliness. One of the main considerations brought forward here relates to the type of human-support functions which the robots are, or will be, expected to perform, and from this, a clear differentiation appears between robots designed to replace humans in environments that were engineered in the past for best human functionality, and robots designed to take functions in the future, in environments which could be better engineered for large-scale human-robot synergy. Other considerations discussed involve the ``life-cycle`` cleanliness of robotic systems, including the materials needs for their construction, their operation, their disposal and, more importantly, their energy consumption which will impact the cycle of natural resources utilization. These considerations are discussed using a variety of possible robotic systems applications in contexts varied as manufacturing, energy recovery and production, emergency situations handling, traffic improvement, waste management, agriculture, and space exploration. In all these applications, the operation costs and complexity of the robots seem to vary in inverse proportion to the amount of engineering that is feasible to make the task environment more …
Date: December 1, 1993
Creator: Pin, F. G.
System: The UNT Digital Library
Dual-benefit technologies at Sandia National Laboratories (open access)

Dual-benefit technologies at Sandia National Laboratories

What does the pulp and paper industry have in common with the desert southwest and nuclear weapons? As a representative of one of the Nations three nuclear weapons design laboratories (Los Alamos National Laboratory, Livermore National Laboratory and Sandia National Laboratories), my goal is to identify ``dual-benefit`` technologies where codevelopment will both strengthen the nation`s competitive position and enhance national security. In development of this presentation, I found more common elements than I could possibly survey in this brief period.
Date: December 31, 1993
Creator: Schaefer, D. W.
System: The UNT Digital Library