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Seismic imaging of reservoir flow properties: Resolving waterinflux and reservoir permeability (open access)

Seismic imaging of reservoir flow properties: Resolving waterinflux and reservoir permeability

Methods for geophysical model assessment, in particuale thecomputation of model parameter resolution, indicate the value and thelimitations of time-lapse data in estimating reservoir flow properties. Atrajectory-based method for computing sensitivities provides an effectivemeans to compute model parameter resolutions. We examine the commonsituation in which water encroaches into a resrvoir from below, as due tothe upward movement of an oil-water contact. Using straight-forwardtechniques we find that, by inclusing reflections off the top and bottomof a reservoir tens of meters thick, we can infer reservoir permeabilitybased upon time-lapse data. We find that, for the caseof water influxfrom below, using multiple time-lapse 'snapshots' does not necessarilyimprove the resolution of reservoir permeability. An application totime-lapse data from the Norne field illustrates that we can resolve thepermeability near a producing well using reflections from threeinterfaces associated with the reservoir.
Date: November 27, 2006
Creator: Vasco, D.W. & Keers, Henk
System: The UNT Digital Library
Analysis of Order Formation in Block Copolymer Thin Films UsingResonant Soft X-Ray Scattering (open access)

Analysis of Order Formation in Block Copolymer Thin Films UsingResonant Soft X-Ray Scattering

The lateral order of poly(styrene-block-isoprene) copolymer(PS-b-PI) thin films is characterized by the emerging technique ofresonant soft X-ray scattering (RSOXS) at the carbon K edge and comparedto ordering in bulk samples of the same materials measured usingconventional small-angle X-ray scattering. We show resonance using theoryand experiment that the loss of scattering intensity expected with adecrease in sample volume in the case of thin films can be overcome bytuning X-rays to the pi* resonance of PS or PI. Using RSOXS, we study themicrophase ordering of cylinder- and phere-forming PS-b-PI thin films andcompare these results to position space data obtained by atomic forcemicroscopy. Our ability to examine large sample areas (~;9000 mu m2) byRSOXS enables unambiguous identification of the lateral lattice structurein the thin films. In the case of the sphere-forming copolymer thin film,where the spheres are hexagonally arranged, the average sphere-to-spherespacing is between the bulk (body-centered cubic) nearest neighbor andbulk unit cell spacings. In the case of the cylinder-forming copolymerthin film, the cylinder-to-cylinder spacing is within experimental errorof that obtained in the bulk.
Date: November 27, 2006
Creator: Virgili, Justin M.; Tao, Yuefei; Kortright, Jeffrey B.; Balsara,Nitash P. & Segalman, Rachel A.
System: The UNT Digital Library
Screening and Ranking Framework (SRF) for Geologic CO2 Storage Site Selection on the Basis of Hse Risk (open access)

Screening and Ranking Framework (SRF) for Geologic CO2 Storage Site Selection on the Basis of Hse Risk

A screening and ranking framework (SRF) has been developedto evaluate potential geologic carbon dioxide (CO2) storage sites on thebasis of health, safety, and environmental (HSE) risk arising from CO2leakage. The approach is based on the assumption that CO2 leakage risk isdependent on three basic characteristics of a geologic CO2 storage site:(1) the potential for primary containment by the target formation; (2)the potential for secondary containment if the primary formation leaks;and (3) the potential for attenuation and dispersion of leaking CO2 ifthe primary formation leaks and secondary containment fails. Theframework is implemented in a spreadsheet in which users enter numericalscores representing expert opinions or published information along withestimates of uncertainty. Applications to three sites in Californiademonstrate the approach. Refinements and extensions are possible throughthe use of more detailed data or model results in place of propertyproxies.
Date: November 27, 2006
Creator: Oldenburg, Curtis M.
System: The UNT Digital Library
The effect of pulse duration on laser-induced damage by 1053-nm light in potassium dihydrogen phosphate crystals (open access)

The effect of pulse duration on laser-induced damage by 1053-nm light in potassium dihydrogen phosphate crystals

Laser induced damage in potassium dihydrogen phosphate (KDP) has previously been shown to depend significantly on pulse duration for 351-nm Gaussian pulses. In this work we studied the properties of damage initiated by 1053-nm temporally Gaussian pulses with 10ns and 3ns FWHM durations. Our results indicate that the number of damage sites induced by 1053-nm light scales with pulse duration ({tau}) as ({tau}{sub 1}/{tau}{sub 2}){sup 0.17} in contrast to the previously reported results for 351-nm light as ({tau}{sub 1}/{tau}{sub 2}){sup 0.35}. This indicates that damage site formation is significantly less probable at longer wavelengths for a given fluence.
Date: November 27, 2006
Creator: Cross, D A; Braunstein, M R & Carr, C W
System: The UNT Digital Library
Design and Use of a Novel Apparatus for Measuring Capsule Fill Hole Conductance (open access)

Design and Use of a Novel Apparatus for Measuring Capsule Fill Hole Conductance

Description and results of a novel apparatus for determining the flow conductance through a laser drilled hole in a spherical shell for inertial confinement fusion experiments are described. The instrument monitors the pressure of an enclosed volume containing the laser pressure drilled capsule as air bleeds through the hole into the shell. From these measurements one obtains the conductance of the fill hole. This system has proven to be a valuable tool for verifying the conduct conductance into the capsule in a timely and nondestructive manner.
Date: November 27, 2006
Creator: Seugling, R M; Nederbragt, W W; Klingmann, J L; Edson, S; Reynolds, J & Cook, R
System: The UNT Digital Library
Reduction of Thermal Conductivity in Wafer-Bonded Silicon (open access)

Reduction of Thermal Conductivity in Wafer-Bonded Silicon

Blocks of silicon up to 3-mm thick have been formed by directly bonding stacks of thin wafer chips. These stacks showed significant reductions in the thermal conductivity in the bonding direction. In each sample, the wafer chips were obtained by polishing a commercial wafer to as thin as 36 {micro}m, followed by dicing. Stacks whose starting wafers were patterned with shallow dots showed greater reductions in thermal conductivity. Diluted-HF treatment of wafer chips prior to bonding led to the largest reduction of the effective thermal conductivity, by approximately a factor of 50. Theoretical modeling based on restricted conduction through the contacting dots and some conduction across the planar nanometer air gaps yielded fair agreement for samples fabricated without the HF treatment.
Date: November 27, 2006
Creator: Liau, ZL; Danielson, LR; Fourspring, PM; Hu, L; Chen, G & Turner, GW
System: The UNT Digital Library
Black Hole Production at the LHC by Standard Model Bulk Fields in the Randall-Sundrum Model. (open access)

Black Hole Production at the LHC by Standard Model Bulk Fields in the Randall-Sundrum Model.

We consider the production of black holes at the LHC in the Randall-Sundrum (RS) model through the collisions of Standard Model(SM) fields in the bulk. In comparison to the previously studied case where the SM fields are all confined to the TeV brane, we find substantial suppressions to the corresponding collider cross sections for all initial states, i.e., gg, qq and gq, where q represents a light quark or anti-quark which lie close to the Planck brane. For b quarks, which are closer to the TeV brane, this suppression effect is somewhat weaker though b quark contributions to the cross section are already quite small due to their relatively small parton densities. Semi-quantitatively, we find that the overall black hole cross section is reduced by roughly two orders of magnitude in comparison to the traditional TeV brane localized RS model with the exact value being sensitive to the detailed localizations of the light SM fermions in the bulk.
Date: November 27, 2006
Creator: Rizzo, Thomas G.
System: The UNT Digital Library
XMM-Newton Observations of HESSJ1813-178 Reveal a Composite Supernova Remnant (open access)

XMM-Newton Observations of HESSJ1813-178 Reveal a Composite Supernova Remnant

Aims--We present X-ray and {sup 12}CO(J=1-0) observations of the very-high-energy (VHE) {gamma}-ray source HESS J1813-178 with the aim of understanding the origin of the {gamma}-ray emission. Methods--High-angular resolution X-ray studies of the VHE {gamma}-ray emission region are performed using 18.6 ks of XMM-Newton data, taken on HESS J1813-178 in October 2005. Using this dataset we are able to undertake spectral and morphological studies of the X-ray emission object with greater precision than previous studies. NANTEN {sup 12}CO(J=1-0) data are used to search for correlations of the {gamma}-ray emission with molecular clouds which could act as target material for {gamma}-ray production in a hadronic scenario. Results--The NANTEN {sup 12}CO(J=1-0) observations show a giant molecular cloud of mass 2.5 x 10{sup 5} M{sub {circle_dot}} at a distance of 4 kpc in the vicinity of HESS J1813-178. Even though there is no direct positional coincidence, this giant cloud might have influenced the evolution of the {gamma}-ray source and its surroundings. The X-ray data show a highly absorbed (n{sub H} {approx} 1 x 10{sup 23} cm{sup -2}) non-thermal X-ray emitting object coincident with the previously known ASCA source AXJ1813-178 showing a compact core and an extended tail towards the north-east, located in the center …
Date: November 27, 2006
Creator: Funk, S.; Hinton, J. A.; Moriguchi, Y.; Aharonian, F. A.; Fukui, Y.; Hofmann, W. et al.
System: The UNT Digital Library
The National Ignition Facility (NIF) A Path to Fusion Energy (open access)

The National Ignition Facility (NIF) A Path to Fusion Energy

Fusion energy has long been considered a promising clean, nearly inexhaustible source of energy. Power production by fusion micro-explosions of inertial confinement fusion (ICF) targets has been a long term research goal since the invention of the first laser in 1960. The NIF is poised to take the next important step in the journey by beginning experiments researching ICF ignition. Ignition on NIF will be the culmination of over thirty years of ICF research on high-powered laser systems such as the Nova laser at LLNL and the OMEGA laser at the University of Rochester as well as smaller systems around the world. NIF is a 192 beam Nd-glass laser facility at LLNL that is more than 90% complete. The first cluster of 48 beams is operational in the laser bay, the second cluster is now being commissioned, and the beam path to the target chamber is being installed. The Project will be completed in 2009 and ignition experiments will start in 2010. When completed NIF will produce up to 1.8 MJ of 0.35 {micro}m light in highly shaped pulses required for ignition. It will have beam stability and control to higher precision than any other laser fusion facility. Experiments using …
Date: November 27, 2006
Creator: Moses, Edward
System: The UNT Digital Library