Report of Investigations No. 132 Continuity and Internal Properties of Gulf Coast Sandstones and their Implications for Geopressured Fluid Production

UT Librarie

Experimental infection of reindeer with bovine viral diarrhea virus

Two 8-month reindeer (Rangifer tarandus) and a 1-month-old Hereford-Holstein calf (Bos taurus) were inoculated intranasally with the Singer (cytopathogenic) strain of bovine viral diarrhea (BVD) virus. Clinical signs in reindeer included loose stools containing blood and mucus, and transient laminitis or coronitis. Signs in the calf were limited to bloody mucus in the stool and lesions in the nasal mucosa. Antibody titers to BVD virus in the reindeer were intermittent, and titers in the calf persisted from days 14 to 63 post-inoculation (PI). Viremia was detected on PI day 4 in one reindeer, days 3-7 in the other, and days 2-7 in the calf. Bovine viral diarrhea virus was isolated from the lung of the calf at necropsy (PI day 63)

Development of tissue surrogates for photoelastic strain analysis of needle insertion

This paper focuses on the development of full-field experimental methods for validating computational models of needle insertion, and specifically the development of suitable tissue surrogate materials. Gelatine also known as “ballistic gel” is commonly used as a tissue surrogate since the modulus of elasticity matches that of tissue. Its birefringent properties also allow the visualisation of strains in polarised light. However, other characteristics of tissue are not well emulated by gelatine, for example the fibrous network of cells of tissue is not well represented by the granular microstructure of gelatine, which tears easily. A range of birefringent flexible materials were developed and calibrated for photoelastic analysis. The most suitable were then used to explore quantitatively the different strain distributions in tissue when subjected to a range of needles with different tip profiles

Beach and vegetation - line changes at Galveston Island, Texas: erosion, deposition, and recovery from Hurricane Alicia.

On August 18, Hurricane Alicia crossed the upper Texas Gulf Beach of Galveston Island. Aerial photographs taken before and after Alicia and field measurements made during the first 2 yr after the storm provide a basis for determining nearshore changes associated with a major hurricane and for predicting potential beach recovery. Alicia caused substantial landward retreat of both the shoreline and the vegetation line. Retreat of the vegetation line ranged from 20 to 145 ft and averaged about 80 ft. Erosion was generally greatest near the Sea Isle and Bay Harbor subdivisions, where storm processes were most intense; beach erosion generally decreased away from San Luis Pass, elevations were lowered as much as 4.5 ft, and many Gulf-front houses were undermined and exposed on the beach after the storm. Alicia eroded more than 2 million yd3 of sand from West Beach. About one tenth of that sand was deposited on the adjacent barrier flat as a washover terrace. Wahover penetration was greatest to the east of the storm's eye and along developed shoreline segments. The remaining eroded beach sand was deposited offshore as shoreface bars or as storm deposits on the inner shelf. The shoreface deposits promoted rapid forebeach accretion during the first post-storm year; at the same time the backbeach elevation remained about 2.5 to 3 ft lower than before the storm, and the natural post-Alicia vegetation line remained essentially unchanged. Recovery of the vegetation line 2 yr after the storm was insignificant, mainly because the depth of beach erosion exceeded root depth, thus eliminating plants from some areas that were densely vegetated before the storm. Natural seaward advancement of the forebeach after Alicia was accompanied by diverse and widespread human alteration of the backbeach in developed communities. These modifications principally involved spreading sand fill, repositioning storm rubble, constructing bulkheads, building artificial dunes, planting dune grasses, watering and fertilizing the grass, and erecting sand fences. These human modifications tended to obscure the natural vegetation line and to narrow the beach. Hurricane Alicia (1983) caused more beach erosion than did Hurricane Allen (1980) but less than Hurricane Carla (1961). Although the vegetation line returned to its pre-Carla position in some West Beach areas, it did not fully recover along most segments because of long-term beach erosion. As in the past, future recovery of the vegetation line will depend on severity of storm damage, storm recurrence and strength, shoreline stability, and coastal climate. This study shows that beach erosion caused by Alicia was substantial, that the Gulf beach of Galveston Island is frequently influenced by storms, and that much of West Beach is eroding. Therefore, natural recovery of the vegetation line to its pre-storm position is unlikely along eroding segments, and substantial seaward advancement even along relatively stable shoreline segments will take several years. Some human activities in developed areas have artificially raised the backbeach and advanced the vegetation line nearly to its pre-storm position. Such manipulation will be difficult to detect as dunes grow and vegetation density increases. Historical records clearly show that Galveston Beachfront property will receive minor storm damage every few years and extreme storm damage about every 20 yr. Frequent storms and long-term beach erosion are important considerations when planning for future use of the beach and barrier island

Thermodynamics of non-local materials: extra fluxes and internal powers

The most usual formulation of the Laws of Thermodynamics turns out to be suitable for local or simple materials, while for non-local systems there are two different ways: either modify this usual formulation by introducing suitable extra fluxes or express the Laws of Thermodynamics in terms of internal powers directly, as we propose in this paper. The first choice is subject to the criticism that the vector fluxes must be introduced a posteriori in order to obtain the compatibility with the Laws of Thermodynamics. On the contrary, the formulation in terms of internal powers is more general, because it is a priori defined on the basis of the constitutive equations. Besides it allows to highlight, without ambiguity, the contribution of the internal powers in the variation of the thermodynamic potentials. Finally, in this paper, we consider some examples of non-local materials and derive the proper expressions of their internal powers from the power balance laws.Comment: 16 pages, in press on Continuum Mechanics and Thermodynamic

Magnetic trapping of ultracold neutrons

Three-dimensional magnetic confinement of neutrons is reported. Neutrons are loaded into an Ioffe-type superconducting magnetic trap through inelastic scattering of cold neutrons with 4He. Scattered neutrons with sufficiently low energy and in the appropriate spin state are confined by the magnetic field until they decay. The electron resulting from neutron decay produces scintillations in the liquid helium bath that results in a pulse of extreme ultraviolet light. This light is frequency downconverted to the visible and detected. Results are presented in which 500 +/- 155 neutrons are magnetically trapped in each loading cycle, consistent with theoretical predictions. The lifetime of the observed signal, 660 s +290/-170 s, is consistent with the neutron beta-decay lifetime.Comment: 17 pages, 18 figures, accepted for publication in Physical Review

Investigating a Hybrid Metaheuristic For Job Shop Rescheduling

Previous research has shown that artificial immune systems can be used to produce robust schedules in a manufacturing environment. The main goal is to develop building blocks (antibodies) of partial schedules that can be used to construct backup solutions (antigens) when disturbances occur during production. The building blocks are created based upon underpinning ideas from artificial immune systems and evolved using a genetic algorithm (Phase I). Each partial schedule (antibody) is assigned a fitness value and the best partial schedules are selected to be converted into complete schedules (antigens). We further investigate whether simulated annealing and the great deluge algorithm can improve the results when hybridised with our artificial immune system (Phase II). We use ten fixed solutions as our target and measure how well we cover these specific scenarios

Atmospheric Heating and Wind Acceleration: Results for Cool Evolved Stars based on Proposed Processes

A chromosphere is a universal attribute of stars of spectral type later than ~F5. Evolved (K and M) giants and supergiants (including the zeta Aurigae binaries) show extended and highly turbulent chromospheres, which develop into slow massive winds. The associated continuous mass loss has a significant impact on stellar evolution, and thence on the chemical evolution of galaxies. Yet despite the fundamental importance of those winds in astrophysics, the question of their origin(s) remains unsolved. What sources heat a chromosphere? What is the role of the chromosphere in the formation of stellar winds? This chapter provides a review of the observational requirements and theoretical approaches for modeling chromospheric heating and the acceleration of winds in single cool, evolved stars and in eclipsing binary stars, including physical models that have recently been proposed. It describes the successes that have been achieved so far by invoking acoustic and MHD waves to provide a physical description of plasma heating and wind acceleration, and discusses the challenges that still remain.Comment: 46 pages, 9 figures, 1 table; modified and unedited manuscript; accepted version to appear in: Giants of Eclipse, eds. E. Griffin and T. Ake (Berlin: Springer

Recent experimental results in sub- and near-barrier heavy ion fusion reactions

Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus will be mainly on the experimental work performed concerning the influence of transfer channels on fusion cross sections and the hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier fusion taught us that cross sections may strongly depend on the low-energy collective modes of the colliding nuclei, and, possibly, on couplings to transfer channels. The coupled-channels (CC) model has been quite successful in the interpretation of the experimental evidences. Fusion barrier distributions often yield the fingerprint of the relevant coupled channels. Recent results obtained by using radioactive beams are reported. At deep sub-barrier energies, the slope of the excitation function in a semi-logarithmic plot keeps increasing in many cases and standard CC calculations over-predict the cross sections. This was named a hindrance phenomenon, and its physical origin is still a matter of debate. Recent theoretical developments suggest that this effect, at least partially, may be a consequence of the Pauli exclusion principle. The hindrance may have far-reaching consequences in astrophysics where fusion of light systems determines stellar evolution during the carbon and oxygen burning stages, and yields important information for exotic reactions that take place in the inner crust of accreting neutron stars.Comment: 40 pages, 63 figures, review paper accepted for EPJ

Physics of Solar Prominences: I - Spectral Diagnostics and Non-LTE Modelling

This review paper outlines background information and covers recent advances made via the analysis of spectra and images of prominence plasma and the increased sophistication of non-LTE (ie when there is a departure from Local Thermodynamic Equilibrium) radiative transfer models. We first describe the spectral inversion techniques that have been used to infer the plasma parameters important for the general properties of the prominence plasma in both its cool core and the hotter prominence-corona transition region. We also review studies devoted to the observation of bulk motions of the prominence plasma and to the determination of prominence mass. However, a simple inversion of spectroscopic data usually fails when the lines become optically thick at certain wavelengths. Therefore, complex non-LTE models become necessary. We thus present the basics of non-LTE radiative transfer theory and the associated multi-level radiative transfer problems. The main results of one- and two-dimensional models of the prominences and their fine-structures are presented. We then discuss the energy balance in various prominence models. Finally, we outline the outstanding observational and theoretical questions, and the directions for future progress in our understanding of solar prominences.Comment: 96 pages, 37 figures, Space Science Reviews. Some figures may have a better resolution in the published version. New version reflects minor changes brought after proof editin