Subsurface Devonian and Mississippian Gas Shale Samples Barnett and Smithwick Shales (Fort Worth Basin) and Woodford and Barnett Shales (Delaware Basin) Core Sampling for Measured Vitrinite Reflectance Determination

This report summarizes activities carried out by the Bureau of Economic Geology (BEG) during Fiscal Year (FY) 2007 for the National Coal Resources Data System State Cooperative Program (NCRDS project). The report represents a departure from those prepared in previous years by providing a collection of Devonian-Mississippian and Mississippian gas-shale samples. Approval for this change in sample type was given by the USGS in March 2008. Samples were collected from whole cores of three wells in Wise and San Saba Counties, Fort Worth Basin, North Texas (Fig. 1), and Pecos County, Delaware Basin, West Texas (Fig. 2) for vitrinite-reflectance (Ro) analysis by the USGS. Other study activities include identification of the sampled shales' precise geographic location and their stratigraphic position.Bureau of Economic Geolog

Subsurface Gas-Shale Samples Of The Upper Devonian And Lower Mississippian Woodford Shale, Permian Basin, West Texas And Southeastern New Mexico: Core Sampling For Measured Vitrinite-Reflectance (Ro) Determination

This report summarizes activities carried out by the Bureau of Economic Geology (BEG) during fiscal year (FY) 2012 for the National Coal Resources Data System State Cooperative Program (NCRDS project). In a continuation of the sampling strategy for measured vitrinite-reflectance (Ro) determination initiated 4 years ago (Hentz and others, 2009) and conducted during the following three years (Hentz and others, 2010, 2011, 2012), this report provides a collection of oil- and gas-shale samples from the oil- and gas-productive Upper Devonian Woodford Shale of the Permian Basin in Texas and New Mexico (Fig. 1). In FY2009, 2010, and 2011, we provided samples of the Eagle Ford Shale from the San Marcos Arch and Maverick Basin areas, samples of the deeper Pearsall Formation from the Maverick Basin of the eastern part of Texas, and samples of the Smithwick Shale from the Fort Worth Basin of north Texas, respectively. As specified in our work plan for FY2010 through 2014 (Hentz, 2010), this year we have provided samples of the productive Upper Devonian Woodford Shale in the Permian Basin of West Texas and southeastern New Mexico.Bureau of Economic Geolog

Large-Scale Integration of Nanoelectromechanical Systems for Gas Sensing Applications

We have developed arrays of nanomechanical systems (NEMS) by large-scale integration, comprising thousands of individual nanoresonators with densities of up to 6 million NEMS per square centimeter. The individual NEMS devices are electrically coupled using a combined series-parallel configuration that is extremely robust with respect to lithographical defects and mechanical or electrostatic-discharge damage. Given the large number of connected nanoresonators, the arrays are able to handle extremely high input powers (>1 W per array, corresponding to <1 mW per nanoresonator) without excessive heating or deterioration of resonance response. We demonstrate the utility of integrated NEMS arrays as high-performance chemical vapor sensors, detecting a part-per-billion concentration of a chemical warfare simulant within only a 2 s exposure period

Piezoelectric nanoelectromechanical resonators based on aluminum nitride thin films

We demonstrate piezoelectrically actuated, electrically tunable nanomechanical resonators based on multilayers containing a 100-nm-thin aluminum nitride (AlN) layer. Efficient piezoelectric actuation of very high frequency fundamental flexural modes up to ~80 MHz is demonstrated at room temperature. Thermomechanical fluctuations of AlN cantilevers measured by optical interferometry enable calibration of the transduction responsivity and displacement sensitivities of the resonators. Measurements and analyses show that the 100 nm AlN layer employed has an excellent piezoelectric coefficient, d_(31)=2.4 pm/V. Doubly clamped AlN beams exhibit significant frequency tuning behavior with applied dc voltage

The structure of epitaxial V2O3 films and their surfaces : a medium energy ion scattering study

Medium energy ion scattering, using 100 keV H+ incident ions, has been used to investigate the growth of epitaxial films, up to thicknesses of ~200 Å, of V2O3 on both Pd(111) and Au(111). Scattered-ion energy spectra provide a measure of the average film thickness and the variations in this thickness, and show that, with suitable annealing, the crystalline quality is good. Plots of the scattering yield as a function of scattering angle, so-called blocking curves, have been measured for two different incidence directions and have been used to determine the surface structure. Specifically, scattering simulations for a range of different model structures show poor agreement with experiment for half-metal (….V’O3V) and vanadyl (….V’O3V=O) terminations, with and without surface interlayer relaxations. However, good agreement with experiment is found for the modified oxygen-termination structure, first proposed by Kresse et al., in which a subsurface V half-metal layer is moved up into the outermost V buckled metal layer to produce a VO2 overlayer on the underlying V2O3, with an associated layer structure of ….O3VV’’V’O3