High-temperature-oxidation-induced ordered structure in Inconel 939 superalloy exposed to oxy-combustion environments (open access)

High-temperature-oxidation-induced ordered structure in Inconel 939 superalloy exposed to oxy-combustion environments

In the integrated oxy-fuel combustion and turbine power generation system, turbine alloys are exposed to high temperature and an atmosphere comprised of steam, CO2 and O2. While surface and internal oxidation of the alloy takes place, the microstructure in the subsurface region also changes due to oxidation that results in the loss of the strengthening precipitates. In an earlier study of the oxidation of Inconel 939 Ni-based superalloy exposed to oxy-fuel combustion environment for up to 1000 hours, a high-temperature-oxidation-induced phase transformation in the sub-surface region was noticed and a two-phase region formed at the expense of strengthening γ' phase. While one of the two phases was identified as the Ni-matrix (γ solid solution, face-center-cubic) phase, the other product phase remained unidentified. In this study, the crystal structure of the unknown phase and its orientation relationship with the parent Ni-matrix phase was investigated through electron diffraction and high-resolution transmission electron microscopy. It was determined that the crystal structure of the unknown phase could be modeled as a ternary derivative of the ordered η-Ni3Ti phase (D024) structure with lattice parameters of a = 0.5092 nm and c = 0.8336 nm, α = 90º, β = 90º and γ = 120º.
Date: April 20, 2013
Creator: Zhu, Jingxi; Wise, Adam; Nuhfer, Thomas; Holcomb, Gordon R.; Jablonski, Paul D.; Sridhar, Seetharaman et al.
System: The UNT Digital Library
2012 SINGLE MOLECULE APPROACHES TO BIOLOGY GORDON RESEARCH CONFERENCE (JULY 15-20, 2012 - MOUNT SNOW RESORT, WEST DOVER VT) (open access)

2012 SINGLE MOLECULE APPROACHES TO BIOLOGY GORDON RESEARCH CONFERENCE (JULY 15-20, 2012 - MOUNT SNOW RESORT, WEST DOVER VT)

Single molecule techniques are rapidly occupying a central role in biological research at all levels. This transition was made possible by the availability and dissemination of robust techniques that use fluorescence and force probes to track the conformation of molecules one at a time, in vitro as well as in live cells. Single-molecule approaches have changed the way many biological problems are studied. These novel techniques provide previously unobtainable data on fundamental biochemical processes that are essential for all forms of life. The ability of single-molecule approaches to avoid ensemble averaging and to capture transient intermediates and heterogeneous behavior renders them particularly powerful in elucidating mechanisms of the molecular systems that underpin the functioning of living cells. Hence, our conference seeks to disseminate the implementation and use of single molecule techniques in the pursuit of new biological knowledge. Topics covered include: Molecular Motors on the Move; Origin And Fate Of Proteins; Physical Principles Of Life; Molecules and Super-resolution Microscopy; Nanoswitches In Action; Active Motion Or Random Diffusion?; Building Blocks Of Living Cells; From Molecular Mechanics To Physiology; Tug-of-war: Force Spectroscopy Of Single Proteins.
Date: April 20, 2012
Creator: Fernandez, Julio
System: The UNT Digital Library
Assessment and Mitigation of Diagnostic-Generated Electromagnetic Interference at the National Ignition Facility (open access)

Assessment and Mitigation of Diagnostic-Generated Electromagnetic Interference at the National Ignition Facility

Electromagnetic interference (EMI) is an ever-present challenge at laser facilities such as the National Ignition Facility (NIF). The major source of EMI at such facilities is laser-target interaction that can generate intense electromagnetic fields within, and outside of, the laser target chamber. In addition, the diagnostics themselves can be a source of EMI, even interfering with themselves. In this paper we describe EMI generated by ARIANE and DIXI, present measurements, and discuss effects of the diagnostic-generated EMI on ARIANE's CCD and on a PMT nearby DIXI. Finally we present some of the efforts we have made to mitigate the effects of diagnostic-generated EMI on NIF diagnostics.
Date: April 20, 2012
Creator: Brown, C. G.; Ayers, M. J.; Felker, B.; Ferguson, W.; Holder, J P; Nagel, S. R. et al.
System: The UNT Digital Library
Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays (open access)

Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays

This report talks about Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays
Date: April 20, 2012
Creator: Aaltonen, T
System: The UNT Digital Library
Saturation of the Two-Plasmon Decay Instability in Long-Scale-Length Plasmas Relevant to Direct-Drive Inertial Confinement Fusion (open access)

Saturation of the Two-Plasmon Decay Instability in Long-Scale-Length Plasmas Relevant to Direct-Drive Inertial Confinement Fusion

Measurements of the hot-electron generation by the two-plasmon-decay instability are made in plasmas relevant to direct-drive inertial confinement fusion. Density-scale lengths of 400 {micro}m at n{sub cr}/4 in planar CH targets allowed the two-plasmon-decay instability to be driven to saturation for vacuum intensities above ~3.5 x 10{sup 14} W cm{sup -2}. In the saturated regime, ~1% of the laser energy is converted to hot electrons. The hot-electron temperature is measured to increase rapidly from 25 to 90 keV as the laser beam intensity is increased from 2 to 7 x 10{sup 14} W cm{sup -2}. This increase in the hot-electron temperature is compared with predictions from nonlinear Zakharov models.
Date: April 20, 2012
Creator: Yaakobi, B.; Hu, S. X.; Chang, P.-Y.; Craxton, R. S.; Edgell, D. H.; Follett, R. et al.
System: The UNT Digital Library
Design of Benchmark Imagery for Validating Facility Annotation Algorithms (open access)

Design of Benchmark Imagery for Validating Facility Annotation Algorithms

None
Date: April 20, 2011
Creator: Roberts, R S; Pope, P A; Vatsavai, R R; Jiang, M; Arrowood, L F; Trucano, T G et al.
System: The UNT Digital Library
The DNA repair endonuclease XPG interacts directly and functionally with the WRN helicase defective in Werner syndrome (open access)

The DNA repair endonuclease XPG interacts directly and functionally with the WRN helicase defective in Werner syndrome

XPG is a structure-specific endonuclease required for nucleotide excision repair (NER). XPG incision defects result in the cancer-prone syndrome xeroderma pigmentosum, whereas truncating mutations of XPG cause the severe postnatal progeroid developmental disorder Cockayne syndrome. We show that XPG interacts directly with WRN protein, which is defective in the premature aging disorder Werner syndrome, and that the two proteins undergo similar sub-nuclear redistribution in S-phase and co-localize in nuclear foci. The co-localization was observed in mid- to late-S-phase, when WRN moves from nucleoli to nuclear foci that have been shown to contain protein markers of both stalled replication forks and telomeric proteins. We mapped the interaction between XPG and WRN to the C-terminal domains of each and show that interaction with the C-terminal domain of XPG strongly stimulates WRN helicase activity. WRN also possesses a competing DNA single-strand annealing activity that, combined with unwinding, has been shown to coordinate regression of model replication forks to form Holliday junction/chicken foot intermediate structures. We tested whether XPG stimulated WRN annealing activity and found that XPG itself has intrinsic strand annealing activity that requires the unstructured R- and C-terminal domains, but not the conserved catalytic core or endonuclease activity. Annealing by XPG is …
Date: April 20, 2011
Creator: Trego, Kelly S.; Chernikova, Sophia B.; Davalos, Albert R.; Perry, J. Jefferson P.; Finger, L. David; Ng, Cliff et al.
System: The UNT Digital Library
Electrically Detected Magnetic Resonance of Neutral Donors Interacting with a Two-Dimensional Electron Gas (open access)

Electrically Detected Magnetic Resonance of Neutral Donors Interacting with a Two-Dimensional Electron Gas

We have measured the electrically detected magnetic resonance of donor-doped silicon field-effect transistors in resonant X- (9.7 GHz) and W-band (94 GHz) microwave cavities. The two-dimensional electron gas (2DEG) resonance signal increases by two orders of magnitude from X- to W-band, while the donor resonance signals are enhanced by over one order of magnitude. Bolometric effects and spin-dependent scattering are inconsistent with the observations. We propose that polarization transfer from the donor to the 2DEG is the main mechanism giving rise to the spin resonance signals.
Date: April 20, 2011
Creator: Lo, C. C.; Lang, V.; George, R. E.; Morton, J. J. L.; Tyryshkin, A. M.; Lyon, A. et al.
System: The UNT Digital Library
Li+ alumino-silicate ion source development for the Neutralized Drift Compression Experiment (NDCX-II) (open access)

Li+ alumino-silicate ion source development for the Neutralized Drift Compression Experiment (NDCX-II)

To heat targets to electron-volt temperatures for the study of warm dense matter with intense ion beams, low mass ions, such as lithium, have an energy loss peak (dE/dx) at a suitable kinetic energy. The Heavy Ion Fusion Sciences (HIFS) program at Lawrence Berkeley National Laboratory will carry out warm dense matter experiments using Li{sup +} ion beam with energy 1.2-4 MeV in order to achieve uniform heating up to 0.1-1 eV. The accelerator physics design of Neutralized Drift Compression Experiment (NDCX-II) has a pulse length at the ion source of about 0.5 {micro}s. Thus for producing 50 nC of beam charge, the required beam current is about 100 mA. Focusability requires a normalized (edge) emittance {approx}2 {pi}-mm-mrad. Here, lithium aluminosilicate ion sources, of {beta}-eucryptite, are being studied within the scope of NDCX-II construction. Several small (0.64 cm diameter) lithium aluminosilicate ion sources, on 70%-80% porous tungsten substrate, were operated in a pulsed mode. The distance between the source surface and the mid-plane of the extraction electrode (1 cm diameter aperture) was 1.48 cm. The source surface temperature was at 1220 C to 1300 C. A 5-6 {micro}s long beam pulsed was recorded by a Faraday cup (+300 V on …
Date: April 20, 2011
Creator: LBNL; Roy, P. K.; Greenway, W.; Kwan, J. W.; Seidl, P. A. & Waldron, W.
System: The UNT Digital Library
Mechanisms for Precipitation Variability of the Eastern Brazil/SACZ Convective Margin (open access)

Mechanisms for Precipitation Variability of the Eastern Brazil/SACZ Convective Margin

None
Date: April 20, 2011
Creator: Ma, H.; Ji, X.; Neelin, J. D. & Mechoso, C. R.
System: The UNT Digital Library
NDCX-II, an Induction Linac for HEDP and IFE Research (open access)

NDCX-II, an Induction Linac for HEDP and IFE Research

The Heavy Ion Fusion Science Virtual National Laboratory in the USA is constructing a new Neutralized Drift Compression eXperiment (NDCX-II) at LBNL. This facility is being developed for high energy density physics and inertial fusion energy research. The 12 m long induction linac in NDCX-II will produce a Li{sup +} beam pulse, at energies of 1.2-3 MeV, to heat target material to the warm dense matter regime ({approx} 1 eV). By making use of special acceleration voltage waveforms, 2.5T solenoid focusing, and neutralized drift compression, 20 - 50 nC of beam charge from the ion source will be compressed longitudinally and radially to achieve a subnanosecond pulse length and mm-scale target spot size. The original Neutralized Drift Compression Experiment (NDCX-I) has successfully demonstrated simultaneous radial and longitudinal compression by imparting a velocity ramp to the ion beam, which then drifts in a neutralizing plasma to and through the final focussing solenoid and onto the target. At higher kinetic energy and current, NDCX-II will offer more than 100 times the peak energy fluence on target of NDCX-I. NDCX-II makes use of many parts from the decommissioned Advanced Test Accelerator (ATA) at LLNL. It includes 27 lattice periods between the injector and …
Date: April 20, 2011
Creator: Kwan, J. W.; Arbelaez, D.; Bieniosek, F. M.; Faltens, A.; Friedman, A.; Galvin, J. et al.
System: The UNT Digital Library
Near Infrared Spectral Imaging of Explosives using a Tunable Optical Parametric Oscillator Laser Source (open access)

Near Infrared Spectral Imaging of Explosives using a Tunable Optical Parametric Oscillator Laser Source

None
Date: April 20, 2011
Creator: Klunder, G. L.; Margalith, E. & Nguyen, L.
System: The UNT Digital Library
The role of Life Cycle Assessment in identifying and reducing environmental impacts of CCS (open access)

The role of Life Cycle Assessment in identifying and reducing environmental impacts of CCS

Life Cycle Assessment (LCA) should be used to assist carbon capture and sequestration (CCS) planners to reduce greenhouse gas (GHG) emissions and avoid unintended environmental trade-offs. LCA is an analytical framework for determining environmental impacts resulting from processes, products, and services. All life cycle stages are evaluated including raw material sourcing, processing, operation, maintenance, and component end-of-life, as well as intermediate stages such as transportation. In recent years a growing number of LCA studies have analyzed CCS systems. We reviewed 50+ LCA studies, and selected 11 studies that compared the environmental performance of 23 electric power plants with and without CCS. Here we summarize and interpret the findings of these studies. Regarding overall climatemitigation effectiveness of CCS, we distinguish between the capture percentage of carbon in the fuels, the net carbon dioxide (CO2) emission reduction, and the net GHG emission reduction. We also identify trade-offs between the climate benefits and the potential increased non-climate impacts of CCS. Emissions of non-CO2 flue gases such as NOx may increase due to the greater throughput of fuel, and toxicity issues may arise due to the use of monoethanolamine (MEA) capture solvent, resulting in ecological and human health impacts. We discuss areas where improvements …
Date: April 20, 2011
Creator: Sathre, Roger; Masanet, Eric; Cain, Jennifer & Chester, Mikhail
System: The UNT Digital Library
Si Pillar Structured Thermal Neutron Detectors: Fabrication Challenges and Performance Expectations (open access)

Si Pillar Structured Thermal Neutron Detectors: Fabrication Challenges and Performance Expectations

None
Date: April 20, 2011
Creator: Nikolic, R. J.; Shao, Q.; Voss, L. F.; Conway, A. M.; Radev, R.; Wang, T. F. et al.
System: The UNT Digital Library
TUNING OF SIZE AND SHAPE OF AU-PT NANOCATALYST FOR DIRECT METHANOL FUEL CELLS (open access)

TUNING OF SIZE AND SHAPE OF AU-PT NANOCATALYST FOR DIRECT METHANOL FUEL CELLS

In this paper, we report the precise control of the size, shape and surface morphology of Au-Pt nanocatalysts (cubes, blocks, octahedrons and dogbones) synthesized via a seed-mediated approach. Gold 'seeds' of different aspect ratios (1 to 4.2), grown by a silver-assisted approach, were used as templates for high-yield production of novel Au-Pt nanocatalysts at a low temperature (40 C). Characterization by electron microscopy (SEM, TEM, HRTEM), energy dispersive X-ray analysis (EDX), UV-Vis spectroscopy, zeta-potential (surface charge), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma mass spectrometry (ICP-MS) were used to better understand their physico-chemical properties, preferred reactivities and underlying nanoparticle growth mechanism. A rotating disk electrode was used to evaluate the Au-Pt nanocatalysts electrochemical performance in the oxygen reduction reaction (ORR) and the methanol oxidation reaction (MOR) of direct methanol fuel cells. The results indicate the Au-Pt dogbones are partially and in some cases completely unaffected by methanol poisoning during the evaluation of the ORR. The ORR performance of the octahedron particles in the absence of MeOH is superior to that of the Au-Pt dogbones and Pt-black, however its performance is affected by the presence of MeOH.
Date: April 20, 2011
Creator: Murph, S.
System: The UNT Digital Library
Laser Technology for Precision Monoenergetic Gamma-Ray Source R&D at Llnl (open access)

Laser Technology for Precision Monoenergetic Gamma-Ray Source R&D at Llnl

Generation of mono-energetic, high brightness gamma-rays requires state of the art lasers to both produce a low emittance electron beam in the linac and high intensity, narrow linewidth laser photons for scattering with the relativistic electrons. Here, we overview the laser systems for the 3rd generation Monoenergetic Gamma-ray Source (MEGa-ray) currently under construction at Lawrence Livermore National Lab (LLNL). We also describe a method for increasing the efficiency of laser Compton scattering through laser pulse recirculation. The fiber-based photoinjector laser will produce 50 {micro}J temporally and spatially shaped UV pulses at 120 Hz to generate a low emittance electron beam in the X-band RF photoinjector. The interaction laser generates high intensity photons that focus into the interaction region and scatter off the accelerated electrons. This system utilizes chirped pulse amplification and commercial diode pumped solid state Nd:YAG amplifiers to produce 0.5 J, 10 ps, 120 Hz pulses at 1064 nm and up to 0.2 J after frequency doubling. A single passively mode-locked Ytterbium fiber oscillator seeds both laser systems and provides a timing synch with the linac.
Date: April 20, 2010
Creator: Shverdin, M. Y.; Bayramian, A.; Albert, F.; Anderson, S. G.; Betts, S. M.; Chu, T. S. et al.
System: The UNT Digital Library
A Linear Tetranuclear Dysprosium(III) Compound Showing Single-Molecule Magnet Behavior (open access)

A Linear Tetranuclear Dysprosium(III) Compound Showing Single-Molecule Magnet Behavior

Although magnetic measurements reveal a single-relaxation time for a linear tetranuclear Dy(III) compound, the wide distribution of the relaxation time observed clearly suggests the presence of two slightly different anisotropic centres, therefore opening new avenues for investigating the relaxation dynamics of lanthanide aggregates.
Date: April 20, 2010
Creator: Ke, Hongshan; Xu, Gong Feng; Guo, Yun-Nan; Gamez, Patrick; Beavers, Christine M; Teat, Simon J et al.
System: The UNT Digital Library
Preface to International Workshop on X-ray Mirror Design, Fabrication, and Metrology (open access)

Preface to International Workshop on X-ray Mirror Design, Fabrication, and Metrology

The International Workshop on X-Ray Mirror Design, Fabrication, and Metrology (IWXM), Osaka, Japan, was held as a satellite meeting of the Conference on Synchrotron Radiation Instrumentation (SRI) 2009, Melbourne, Australia, in October, 2009. The workshop was organized by a collaboration of scientists from a number of leading synchrotron institutions and universities around the World, such as Osaka University, SPring-8, KEK (Japan), ALS, APS and NSLS (USA), ELETTRA (Italy), ESRF, Synchrotron SOLEIL (France), BESSY (Germany), Diamond (UK), SSRF (China), NSRRC (Taiwan) and PAL (Korea). The workshop followed a series of parallel workshops focused on metrology (1st, 2nd and 3rd International Workshop on Metrology for X-ray and Neutron Optics) and on active X-ray optics (1st and 2nd X-ray and XUV Active Optics Workshop, ACTOP06 and ACTOP08) and included the 3rd workshop on X-ray and EUV active optics (ACTOP09). The workshop brought together more than 100 participants: manufacturers, optical and mechanical engineers, designers, and users of X-ray optics; allowing for free exchange of ideas, highlighting of existing problems and challenges, and searching for ways to improve existing instrumentation for sub-microradian and sub-nanometer accuracy. A visit to the Osaka University mirror fabrication laboratory, SPring-8, and the X-ray free electron laser (XFEL) facility was included …
Date: April 20, 2010
Creator: Yamauchi, Kazuto; Yashchuk, Valeriy V. & Cocco, Daniele
System: The UNT Digital Library
Grid-based methods for diatomic quantum scattering problems II: Time-dependent treatment of single- and two-photon ionization of H2+ (open access)

Grid-based methods for diatomic quantum scattering problems II: Time-dependent treatment of single- and two-photon ionization of H2+

The time-dependent Schr\"odinger equation for H2+ in a time-varying electromagnetic field is solved in the fixed-nuclei approximation using a previously developed finite-element/ discrete variable representation in prolate spheroidal coordinates. Amplitudes for single- and two-photon ionization are obtained using the method of exterior complex scaling to effectively propagate the field-free solutions from the end of the radiation pulse to infinite times. Cross sections are presented for one-and two-photon ionization for both parallel and perpendicular polarization of the photon field, as well as photoelectron angular distributions for two-photon ionization.
Date: April 20, 2009
Creator: Rescigno, Thomas N.; Tao, L. & McCurdy, C.W.
System: The UNT Digital Library
Mineral transformation and biomass accumulation associated with uranium bioremediation at Rifle, Colorado (open access)

Mineral transformation and biomass accumulation associated with uranium bioremediation at Rifle, Colorado

Injection of organic carbon into the subsurface as an electron donor for bioremediation of redox-sensitive contaminants like uranium often leads to mineral transformation and biomass accumulation, both of which can alter the flow field and potentially bioremediation efficacy. This work combines reactive transport modeling with a column experiment and field measurements to understand the biogeochemical processes and to quantify the biomass and mineral transformation/accumulation during a bioremediation experiment at a uranium contaminated site near Rifle, Colorado. We use the reactive transport model CrunchFlow to explicitly simulate microbial community dynamics of iron and sulfate reducers, and their impacts on reaction rates. The column experiment shows clear evidence of mineral precipitation, primarily in the form of calcite and iron monosulfide. At the field scale, reactive transport simulations suggest that the biogeochemical reactions occur mostly close to the injection wells where acetate concentrations are highest, with mineral precipitate and biomass accumulation reaching as high as 1.5% of the pore space. This work shows that reactive transport modeling coupled with field data can be an effective tool for quantitative estimation of mineral transformation and biomass accumulation, thus improving the design of bioremediation strategies.
Date: April 20, 2009
Creator: Li, L.; Steefel, C. I.; Williams, K. H.; Wilkins, M. J. & Hubbard, S. S.
System: The UNT Digital Library
Predicted Geology of the Pahute Mesa-Oasis Valley Phase II Drilling Initiative (open access)

Predicted Geology of the Pahute Mesa-Oasis Valley Phase II Drilling Initiative

Pahute Mesa–Oasis Valley (PM-OV) Phase II drilling will occur within an area that encompasses approximately 117 square kilometers (45 square miles) near the center of the Phase I PM-OV hydrostratigraphic framework model area. The majority of the investigation area lies within dissected volcanic terrain between Pahute Mesa on the north and Timber Mountain on the south. This area consists of a complex distribution of volcanic tuff and lava of generally rhyolitic composition erupted from nearby calderas and related vents. Several large buried volcanic structural features control the distribution of volcanic units in the investigation area. The Area 20 caldera, including its structural margin and associated caldera collapse collar, underlies the northeastern portion of the investigation area. The southern half of the investigation area lies within the northwestern portion of the Timber Mountain caldera complex, including portions of the caldera moat and resurgent dome. Another significant structural feature in the area is the west-northwest-trending Northern Timber Mountain moat structural zone, which bisects the northern portion of the investigation area and forms a structural bench. The proposed wells of the UGTA Phase II drilling initiative can be grouped into four generalized volcanic structural domains based on the stratigraphic distribution and structural position …
Date: April 20, 2009
Creator: National Security Technologies, LLC
System: The UNT Digital Library
Self-validated Variance-based Methods for Sensitivity Analysis of Model Outputs (open access)

Self-validated Variance-based Methods for Sensitivity Analysis of Model Outputs

Global sensitivity analysis (GSA) has the advantage over local sensitivity analysis in that GSA does not require strong model assumptions such as linearity or monotonicity. As a result, GSA methods such as those based on variance decomposition are well-suited to multi-physics models, which are often plagued by large nonlinearities. However, as with many other sampling-based methods, inadequate sample size can badly pollute the result accuracies. A natural remedy is to adaptively increase the sample size until sufficient accuracy is obtained. This paper proposes an iterative methodology comprising mechanisms for guiding sample size selection and self-assessing result accuracy. The elegant features in the the proposed methodology are the adaptive refinement strategies for stratified designs. We first apply this iterative methodology to the design of a self-validated first-order sensitivity analysis algorithm. We also extend this methodology to design a self-validated second-order sensitivity analysis algorithm based on refining replicated orthogonal array designs. Several numerical experiments are given to demonstrate the effectiveness of these methods.
Date: April 20, 2009
Creator: Tong, C
System: The UNT Digital Library
Statistical Analysis and Geologic Evaluation of Laboratory-Derived Physical Property Data for Selected Nevada Test Site Core Samples of Non-Zeolitized Tuffs (open access)

Statistical Analysis and Geologic Evaluation of Laboratory-Derived Physical Property Data for Selected Nevada Test Site Core Samples of Non-Zeolitized Tuffs

A statistical analysis and geologic evaluation of recently acquired laboratory-derived physical property data are being performed to better understand and more precisely correlate physical properties with specific geologic parameters associated with non-zeolitized tuffs at the Nevada Test Site. Physical property data include wet and dry bulk density, grain density (i.e., specific gravity), total porosity, and effective porosity. Geologic parameters utilized include degree of welding, lithology, stratigraphy, geographic area, and matrix mineralogy (i.e., vitric versus devitrified). Initial results indicate a very good correlation between physical properties and geologic parameters such as degree of welding, lithology, and matrix mineralogy. However, physical properties appear to be independent of stratigraphy and geographic area, suggesting that the data are transferrable with regards to these two geologic parameters. Statistical analyses also indicate that the assumed grain density of 2.65 grams per cubic centimeter used to calculate porosity in some samples is too high. This results in corresponding calculated porosity values approximately 5 percent too high (e.g., 45 percent versus 40 percent), which can be significant in the lower porosity rocks. Similar analyses and evaluations of zeolitic tuffs and carbonate rock physical properties data are ongoing as well as comparisons to geophysical log values.
Date: April 20, 2009
Creator: National Security Technologies, LLC
System: The UNT Digital Library