Potentiometric Level of the Deep-Basin Brine Aquifer, Palo Duro Basin, Texas Panhandle

As part of the investigation into the hydrology of the Palo Duro Basin, potentiometric surface maps have been developed to depict the potential distribution within the Wolfcamp aquifer, the upper Pennsylvanian aquifer, and the lower Pennsylvanian aquifer. The maps for the Wolfcamp and upper Pennsylvanian were included in earlier CSR sections (December 1982 and February 1984). In this report, geostatistical analysis is employed to map the hydraulic head distribution in rocks of lower Pennsylvanian age across the broader Permian Basin region, encompassing the Palo Duro, Delaware, Midland, and Anadarko Basins. The lower Pennsylvanian comprises rocks of the Bend and Strawn groups. Variogram analysis was utilized to characterize data variability, followed by kriging to estimate head values based on available data while minimizing variance in the estimates. The resulting estimates were then contoured using CPS-1 (1979, Radian Corporation). Due to limited lower Pennsylvanian data specifically from the Palo Duro Basin, the potential surface for this period is poorly defined in the Palo Duro Basin. However, it can be constrained by data from surrounding basins where information is more abundant.Bureau of Economic Geolog

Evaluation of the J. Friemel #1 Vertical Well Tests, Deaf Smith County, Palo Duro Basin, Texas Panhandle

This report describes the vertical well test in the Wolfcamp interval of the J. Friemel #1 hydrologic test well. Included are (1) purpose of the test, (2) test approach, (3) "what went right with the test," (4) "what went wrong with the test," and (5) what should be done differently next time. Purpose of the Test The overall purpose of performing the vertical well test was to begin to estimate the importance of fracture permeability in the regional flow system. This aspect of the regional flow system has not been tested in either field tests or modeling exercises. It is probable that there is vertical fluid movement through the various hydrologic units of the Palo Duro Basin. Within each of the hydrologic units as well as across formation boundaries vertical flow may be through fractures. The purpose of this test was to assess the importance of fracture permeability between two porous Wolfcamp carbonate intervals.Bureau of Economic Geolog

SOUTHERN FARMERS EXPOSURE TO INCOME RISK UNDER THE 1996 FARM BILL

Arguably, since the 1930s, what farmers produced has been markedly influenced by farm programs. The 1996 farm bill affects farmers in terms of what they produce and their level of risk exposure. This paper investigates the farm level impacts of the 1996 farm bill on the South. Focus group perceptions of risk sources, observed acreage changes, and the farm level impact of increased price risk are evaluated.Agricultural and Food Policy, Agricultural Finance,

Charge and spin state readout of a double quantum dot coupled to a resonator

State readout is a key requirement for a quantum computer. For semiconductor-based qubit devices it is usually accomplished using a separate mesoscopic electrometer. Here we demonstrate a simple detection scheme in which a radio-frequency resonant circuit coupled to a semiconductor double quantum dot is used to probe its charge and spin states. These results demonstrate a new non-invasive technique for measuring charge and spin states in quantum dot systems without requiring a separate mesoscopic detector

Surface Geology of the Palo Duro and Dalhart Basins, Area, Texas

The Texas Panhandle includes primarily two physiographic provinces: the High Plains which overlies the Dalhart and most of the Palo Duro Basin and the Rolling Plains characterizing the eastern part of the Palo Duro Basin area. These two provinces are separated by the Caprock Escarpment, a prominent erosional feature along which relief locally exceeds 1,500 ft (500 m). The High Plains is developed on the Tertiary Ogallala Formation and forms a broad, flat plain having a regional slope to the southeast of 8 to 10 ft per mile. The Rolling Plains were formed by erosion of the Ogallala Formation which exposed the varying lithologies of the underlying Permian and Triassic age units. The easterly flowing Canadian River divides the High Plains into two sections: the Northern High Plains overlying the Dalhart Basin, and the Southern High Plains, or Llano Estacada, overlying the Palo Duro Basin. Prominent escarpments bounding the High Plains on the west, east, and along the Canadian River Valley are the result of Quaternary erosion. These escarpments provide most of the Tertiary and Triassic rock exposures. The flat surface of the High Plains is interrupted by numerous playas, dunes, and a surface drainage system composed of linear draws or channels. Pleistocene strata are exposed in some stream-cut channels and large playas on the High Plains surface. With the exception of the Canadian River drainage system and minor streams, major portions of the High Plains surface are without external drainage.Bureau of Economic Geolog

Use of Kriging to Estimate the Wolfcampian and San Andres Potentiometric Surfaces, Palo Duro Basin, Texas Panhandle

Kriging is a statistical method historically used to estimate mineral reserves and more recently applied to estimate spatially-distributed or regionalized variables in hydrologic studies, such as ground-water fluid potential or transmissivity. In estimating these regionalized variables, kriging serves two main purposes. Firstly, it can generate a contour map of the variable with an associated measure of error. Secondly, it can optimize the location of additional samples, particularly valuable in acquiring data for ground-water potential in deep formations, which often involves drilling expensive wells. Kriging has been previously employed to estimate water elevation in studies such as those conducted at the Department of Energy Hanford Reservation in the Pasco Basin, Washington (Doctor, 1979), and in a study of the multilayer aquifer system underlying Venice, Italy (Volpi and Gambolati, 1979). In both cases, actual water level measurements were utilized. This report discusses the use of kriging methods by The University of Texas, Bureau of Economic Geology (UT/BEG), in the context of nuclear waste isolation feasibility studies in the Palo Duro Basin, funded by the Department of Energy under contract DE-AC97-80ET46615. Kriging has been employed by UT/BEG to estimate the ground-water potentiometric surfaces of the permeable San Andres cycle four dolomite and the Wolfcampian aquifer. The San Andres Formation study utilized water level measurements and drill-stem-test (DST) pressures. Kriging was applied to minimize the variation of the DST data and reveal the regional potentiometric surface. The Wolfcamp study relied solely on DST pressures, with kriging employed to model the variation in the data and generate a contoured map of the potentiometric surface. The kriging techniques employed by the Bureau of Economic Geology involve three steps: (1) variogram analysis, (2) kriging, and (3) contouring krige block estimates. Computer programs used for calculating the empirical variogram statistics, krige block estimates, and krige block variances were obtained from Dr. Young C. Kim and are detailed in Knudsen and Kim, 1978. For a comprehensive understanding of regionalized variables theory and kriging, please refer to Knudsen and Kim, 1978. A brief overview of the techniques used at the Bureau follows.Bureau of Economic Geolog

Relative Sound Localization for Sources in a Haphazard Speaker Array

A rapidly deployable, easy to use method of automatically configuring multi-channel audio systems is described. Compensating for non-ideal speaker positioning is a problem seen in immersive audio-visual art installations, home theater surround sound setups, and live concerts. Manual configuration requires expertise and time, while automatic methods promise to reduce these costs, enabling quick and easy setup and operation. Ideally the system should outperform a human in aural sound source localization. A naïve method is proposed and paired software is evaluated aiming to cut down on setup time, use readily available hardware, and enable satisfactory multi-channel spatialization and sound-source localization

Influence of strain and oxygen vacancies on the magnetoelectric properties of multiferroic bismuth ferrite

The dependencies on strain and oxygen vacancies of the ferroelectric polarization and the weak ferromagnetic magnetization in the multiferroic material bismuth ferrite, BiFeO_3, are investigated using first principles density functional theory calculations. The electric polarization is found to be rather independent of strain, in striking contrast to most conventional perovskite ferroelectrics. It is also not significantly affected by oxygen vacancies, or by the combined presence of strain and oxygen vacancies. The magnetization is also unaffected by strain, however the incorporation of oxygen vacancies can alter the magnetization slightly, and also leads to the formation of Fe^{2+}. These results are discussed in light of recent experiments on epitaxial films of BiFeO_3 which reported a strong thickness dependence of both magnetization and polarization.Comment: 9 pages, 3 figure

Characterization Study of the Ogallala Aquifer, Northwest Texas

The Ogallala aquifer, which is the main water supply in the High Plains of Texas, is being severely depleted by extensive pumpage for irrigation. The aquifer overlies the Permian evaporites that are being considered as a potential repository for the disposal of high-level nuclear wastes. Potential contamination of the aquifer by these wastes and further depletion of the limited water resources are major concerns of the people in the area. The purpose of this work is to develop a general hydrogeologic characterization of the aquifer that will serve as a firm basis for accurate evaluation of aquifer recharge mechanisms relevant to problems stemming from accidental spills of radionuclides at the land surface and possible interactions of the radionuclides with deeper hydrologic units. Aquifer hydraulics relevant to problems that may be encountered in shaft construction were studied as well. The existing geologic, hydrologic, geochemical, and isotopic data are integrated into a regional hydrogeologic model for water and solutes. The model enables (1) an understanding of recharge/discharge relationships, ages of water, and rock-water interactions, and (2) the tracing of cross-formational flow between the Ogallala and the underlying aquifers. This report presents preliminary conclusions of research conducted from August 1984 through August 1985.Bureau of Economic Geolog