Urban hydrology and other environmental aspects of the Austin Area : Austin Geological Society fall field trip, December 8, 1979

UT Librarie

Geologic History, Depostional Envirnoment, Processes, and Hydology of Galveston Island, Texas

Galveston Island is a very young geologic feature compared to the Earth's age of approximately 4.5 billion years. Estimates suggest that Galveston Island and other Texas barrier islands began forming as submerged bars no more than 4,500 to 5,500 years ago, based on radiocarbon dating of shells (Fisk, 1959). The following descriptions of development history, present shoreline conditions, and processes and environments have been modified from various sources including LeBlanc and Hodgson (1959), Bernard and others (1970), Fisher and others (1972), Morton (1974), McGowen and others (1977), Weise and White (1980), and Paine and Barton (1989). The origin of barrier islands has been the subject of debate, with different processes or combinations of processes shaping and modifying them. These processes depend on variables such as sediment source, type, and supply, rate and direction of relative sea-level changes, basin shape, continental shelf slope, currents, waves, and tides. Three of the most discussed theories of barrier-island origin include development from an offshore shoal or submerged sandbar, development by spit accretion resulting from longshore drift, and development by drowning of the area landward of mainland beach sand ridges (Wanless, 1974). One possible explanation for the origin of Galveston Island is that it developed from offshore shoals, with later growth aided by spit accretion. The offshore shoals might have originally been mainland beach ridges submerged during a rise in sea level. All three processes may have played a role in the island's origin, with different segments of the island undergoing different processes at varying rates during their development.Bureau of Economic Geolog

Heat pipes for wing leading edges of hypersonic vehicles

Wing leading edge heat pipes were conceptually designed for three types of vehicle: an entry research vehicle, aero-space plane, and advanced shuttle. A full scale, internally instrumented sodium/Hastelloy X heat pipe was successfully designed and fabricated for the advanced shuttle application. The 69.4 inch long heat pipe reduces peak leading edge temperatures from 3500 F to 1800 F. It is internally instrumented with thermocouples and pressure transducers to measure sodium vapor qualities. Large thermal gradients and consequently large thermal stresses, which have the potential of limiting heat pipe life, were predicted to occur during startup. A test stand and test plan were developed for subsequent testing of this heat pipe. Heat pipe manufacturing technology was advanced during this program, including the development of an innovative technique for wick installation

Geology of the Superconducting Super Collider Project Area

The site selected for the Superconducting Super Collider (SSC) is located in Ellis County in North-Central Texas. The area is situated on the rolling prairies near the margin of the West Gulf Coastal Plain. The White Rock Escarpment (west of the site) marks the western limit of the east-dipping Austin Chalk. The Eagle Ford Prairie extends westward from the White Rock Escarpment. The Blackland Prairie is developed on the Taylor Marl, which overlies the Austin Chalk. The project area lies within the Trinity River drainage basin and is characterized by a flat to gently rolling topography dissected locally by streams. Relief in the region is approximately 350 feet (107 meters). Surface elevations along the line of the SSC tunnel range from about 460 feet to 740 feet (140 to 225 meters).Bureau of Economic Geolog

Bloating characteristics of east Texas clays

Bureau Publication GC6501 - to purchase a print copy please go to: https://store.beg.utexas.edu/geologic-circulars/383-gc6501.htmlIncidence of bloating among approximately 600 clay samples from East Texas, ranging in age from Gulfian (Late Cretaceous) to Recent, correlates principally with clay mineralogy-and pH--together an indication of bulk composition--and to a lesser extent with texture, loss on ignition, and content of nonclay refractory minerals. Clay-mineral and pH data permit prediction of bloating with an accuracy of about 80 percent. Montmorillonitic and illitic clays are the best bloaters; bloating occurs in more than 80 percent of clays consisting of less than 30 percent kaolinite, more than l 0 percent illite, and between 20 and 90 percent montmorillonite. Only 10 percent of the high-alumina clays (more than 50 percent kaolinite) bloat; these generally are plastic and carbonaceous. Value of pH is an index of the amount of certain flux and gas-forming materials in clays; accordingly, bloating incidence generally increases with increase in pH. Incidence of bloating also increases slightly with decrease in grain size, increase in plasticity, increase in loss on ignition, and decrease in content of nonclay refractory minerals.Bureau of Economic GeologyUT Librarie

Tests of Landscape Influence: Nest Predation and Brood Parasitism in Fragmented Ecosystems

The effects of landscape fragmentation oil nest predation and brood parasitism, the two primary Causes of avian reproductive failure, have been difficult to generalize across landscapes, yet few Studies have clearly considered the context and spatial scale of: fragmentation. Working in two river systems fragmented by agricultural and rural-housing development, we tracked nesting Success and brood parasitism in \u3e 2500 bird nests in 38 patches of deciduous riparian woodland. Patches oil both river Systems were embedded in one of two local contexts (buffered from agriculture by coniferous forest, or adjacent to agriculture), but the abundance of agriculture and human habitation within 1 km of each patch was highly variable. We examined evidence for three models of landscape effects oil nest predation based on (1) the relative importance of generalist agricultural nest predators, (2) predators associated with the natural habitats typically removed by agricultural development, or (3) an additive combination of: these two predator communities. We found strong support for all additive predation model in which landscape features affect nest predation differently at different spatial scales. Riparian habitat with forest buffers had higher nest predation rates than sites adjacent to agriculture, but nest predation also increased with increasing agriculture in the larger landscape Surrounding each site. These results suggest that predators living in remnant woodland buffers, as well as generalist nest predators associated with agriculture, affect nest predation rates, but they appear to respond at different spatial scales. Brood parasitism, in Contrast, Was unrelated to agricultural abundance oil the landscape, but showed a strong nonlinear relationship with farm and house density, indicating a critical point at which increased human habitat Causes increased brood parasitism. Accurate predictions regarding landscape effects oil nest predation and brood parasitism will require an increased appreciation of the multiple scales at which landscape components influence predator and parasite behavior

Determination of Fluoxetine and Norfluoxetine Concentrations in Cadaveric Allograft Skin

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90146/1/j.1875-9114.1998.tb03908.x.pd

New bronchoscopic treatment modalities for patients with chronic bronchitis

Chronic bronchitis is a chronic, progressive disease that is difficult to treat. Despite much effort, patients remain highly symptomatic. Currently, a number of innovative bronchoscopic treatments for this disease are under investigation. Liquid nitrogen metered cryospray, bronchial rheoplasty and balloon desobstruction all aim to destroy the hyperplastic goblet cells and excess submucous glands using different strategies. These therapies are in an early phase of clinical research and larger randomised controlled trials are needed to confirm the pilot data available and to evaluate the treatment durability. The fourth technique, targeted lung denervation (TLD), aims to decrease the release of acetylcholine, which regulates smooth muscle tone and mucus production by ablating the parasympathetic nerves running alongside the main bronchi. Evaluation of this treatment is at a more advanced stage and promising effects on exacerbation frequency have been shown. However, confirmation of the benefit in improvement in chronic bronchitis symptoms is still needed

The Impact Of A Collegiate Course In Bargaining And Negotiation On Students Perceptions Of Their Own And Others Attitudes And Behaviors: An Exploratory Study

This article presents a discussion of the importance of a course in bargaining and negotiation to university-level students in an accredited business school environment. In addition to discussing recommended content, pedagogy, and assessment methods, the results of a study that examines the impact of the course on students perceptions of skills, attitudes, and behaviors associated with effective negotiation is presented. The results of the study clearly demonstrate significant shifts in students perceptions regarding power, constructive dialogue, and the appropriate role and definition of winning in such bargaining and negotiation encounters