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Differentiating neutrino models on the basis of $\theta_{13}$ and lepton flavor violation (open access)

Differentiating neutrino models on the basis of $\theta_{13}$ and lepton flavor violation

The authors show how models of neutrino masses and mixings can be differentiated on the basis of their predictions for {theta}{sub 13} and lepton flavor violation in radiative charged lepton decays and {mu} - e conversion. They illustrate the lepton flavor violation results for five predictive SO(10) SUSY GUT models and point out the relative importance of their heavy right-handed neutrino mass spectra and {theta}{sub 13} predictions.
Date: March 1, 2008
Creator: Albright, Carl H.
System: The UNT Digital Library
The U.S. Department of Energy's Aerial Measuring System (AMS) (open access)

The U.S. Department of Energy's Aerial Measuring System (AMS)

For nearly 40 years, aerial radiological search and survey missions have been performed by the United States Department of Energy's (USDOE) Remote Sensing Laboratory (RSL). Originally created in 1967 as Aerial Measurement Operations (AMO), the AMS mission has expanded to include acquiring baseline measurements, performing periodic area monitoring, and responding to radiological emergencies. In an accident scenario, AMS fixed-wing and/or rotary-wing systems can be deployed to map radiological deposition. A fixed-wing system is on standby twenty-fours per day, seven days per week and can be deployed within four hours of notification. It can quickly evaluate high levels of radiation which may constitute immediate health risks. To accomplish its mission the fixed-wing aircraft utilizes the Spectral Aerial Radiological Computer System (SPARCS) which records gross count and spectral information. Data from SPARCS is telemetered to ground stations and secure websites where it can be viewed and evaluated in near-real time. The rotary-wing system deploys following the critical phase of an accident and supports the DOE's Consequence Management Response Team (CMRT) in determining long term consequences of the accident. The rotary wing aircraft utilizes the Radiation and Environmental Data Acquisition and Recording System (REDAR). A 25-liter sodium iodide (NaI) spectral system and precise …
Date: March 1, 2008
Creator: Marianno, Craig
System: The UNT Digital Library
Evolution of the Surface Science of Catalysis from Single Crystals to Metal Nanoparticles under Pressure (open access)

Evolution of the Surface Science of Catalysis from Single Crystals to Metal Nanoparticles under Pressure

Vacuum studies of metal single crystal surfaces using electron and molecular beam scattering revealed that the surface atoms relocate when the surface is clean (reconstruction) and when it is covered by adsorbates (adsorbate induced restructuring). It was also discovered that atomic steps and other low coordination surface sites are active for breaking chemical bonds (H-H, O=O, C-H, C=O and C-C) with high reaction probability. Investigations at high reactant pressures using sum frequency generation (SFG)--vibrational spectroscopy and high pressure scanning tunneling microscopy (HPSTM) revealed bond breaking at low reaction probability sites on the adsorbate-covered metal surface, and the need for adsorbate mobility for continued turnover. Since most catalysts (heterogeneous, enzyme and homogeneous) are nanoparticles, colloid synthesis methods were developed to produce monodispersed metal nanoparticles in the 1-10 nm range and controlled shapes to use them as new model catalyst systems in two-dimensional thin film form or deposited in mesoporous three-dimensional oxides. Studies of reaction selectivity in multipath reactions (hydrogenation of benzene, cyclohexene and crotonaldehyde) showed that reaction selectivity depends on both nanoparticle size and shape. The oxide-metal nanoparticle interface was found to be an important catalytic site because of the hot electron flow induced by exothermic reactions like carbon monoxide oxidation.
Date: March 6, 2008
Creator: Somorjai, Gabor A. & Park, Jeong Y.
System: The UNT Digital Library
A High-Flux, Flexible Membrane with Parylene-encapsulated Carbon Nanotubes (open access)

A High-Flux, Flexible Membrane with Parylene-encapsulated Carbon Nanotubes

We present fabrication and characterization of a membrane based on carbon nanotubes (CNTs) and parylene. Carbon nanotubes have shown orders of magnitude enhancement in gas and water permeability compared to estimates generated by conventional theories [1, 2]. Large area membranes that exhibit flux enhancement characteristics of carbon nanotubes may provide an economical solution to a variety of technologies including water desalination [3] and gas sequestration [4]. We report a novel method of making carbon nanotube-based, robust membranes with large areas. A vertically aligned dense carbon nanotube array is infiltrated with parylene. Parylene polymer creates a pinhole free transparent film by exhibiting high surface conformity and excellent crevice penetration. Using this moisture-, chemical- and solvent-resistant polymer creates carbon nanotube membranes that promise to exhibit high stability and biocompatibility. CNT membranes are formed by releasing a free-standing film that consists of parylene-infiltrated CNTs, followed by CNT uncapping on both sides of the composite material. Thus fabricated membranes show flexibility and ductility due to the parylene matrix material, as well as high permeability attributed to embedded carbon nanotubes. These membranes have a potential for applications that may require high flux, flexibility and durability.
Date: March 14, 2008
Creator: Park, H. G.; In, J.; Kim, S.; Fornasiero, F.; Holt, J. K.; Grigoropoulos, C. P. et al.
System: The UNT Digital Library
Separation of Yeast Cells from MS2 Viruses Using Acoustic Radiation Force (open access)

Separation of Yeast Cells from MS2 Viruses Using Acoustic Radiation Force

We report a rapid and robust separation of Saccharomyces cerevisiae and MS2 bacteriophage using acoustic focusing in a microfluidic device. A piezoelectric transducer (PZT) generates acoustic standing waves in the microchannel. These standing waves induce acoustic radiation force fields that direct microparticles towards the nodes (i.e., pressure minima) or the anti-nodes (i.e., pressure maxima) of the standing waves depending on the relative compressidensity between the particle and the suspending liquid.[1] For particles larger than 2 {micro}m, the transverse velocities generated by these force fields enable continuous, high throughput separation. Extensive work in the last decade [2-4] has demonstrated acoustic focusing for manipulating microparticles or biological samples in microfluidic devices. This prior work has primarily focused on experimental realization of acoustic focusing without modeling or with limited one-dimensional modeling estimates. We recently developed a finite element modeling tool to predict the two-dimensional acoustic radiation force field perpendicular to the flow direction in microfluidic devices.[1] Here we compare results from this model with experimental parametric studies including variations of the PZT driving frequencies and voltages as well as various particle sizes and compressidensities. These experimental parametric studies also provide insight into the development of an adjustable 'virtual' pore-size filter as well as …
Date: March 27, 2008
Creator: Jung, B.; Fisher, K.; Ness, K.; Rose, K. A. & Mariella, R. P., Jr.
System: The UNT Digital Library
The Surface Wave Magnitude for the 9 October 2006 North Korean Nuclear Explosion (open access)

The Surface Wave Magnitude for the 9 October 2006 North Korean Nuclear Explosion

Surface waves were generated by the North Korean nuclear explosion of 9 October 2006 and recorded at epicentral distances up to 34 degrees, from which we estimated a surface wave magnitude (M{sub s}) of 2.94 with an interstation standard deviation of 0.17 magnitude units. The International Data Centre estimated a body wave magnitude (m{sub b}) of 4.1. This is the only explosion we have analyzed that was not easily screened as an explosion based on the differences between the M{sub s} and m{sub b} estimates. Additionally, this M{sub s} predicts a yield, based on empirical M{sub s}/Yield relationships, that is almost an order of magnitude larger then the 0.5 to 1 kiloton reported for this explosion. We investigate how emplacement medium effects on surface wave moment and magnitude may have contributed to the yield discrepancy.
Date: March 11, 2008
Creator: Bonner, J; Herrmann, R; Harkrider, D & Pasyanos, M
System: The UNT Digital Library
Digitral Down Conversion Technology for Tevatron Beam Line Tuner at FNAL (open access)

Digitral Down Conversion Technology for Tevatron Beam Line Tuner at FNAL

Fermilab is presently in Run II collider operations and is developing instrumentation to improve luminosity. Improving the orbit matching between accelerator components using a Beam Line Tuner (BLT) can improve the luminosity. Digital Down Conversion (DDC) has been proposed as a method for making more accurate beam position measurements. Fermilab has implemented a BLT system using a DDC technique to measure orbit oscillations during injections from the Main Injector to the Tevatron. The output of a fast ADC is downconverted and filtered in software. The system measures the x and y positions, the intensity, and the time of arrival for each proton or antiproton bunch, on a turn-by-turn basis, during the first 1024 turns immediately following injection. We present results showing position, intensity, and time of arrival for both injected and coasting beam. Initial results indicate a position resolution of {approx}20 to 40 microns and a phase resolution of {approx}25 ps.
Date: March 17, 2008
Creator: Schappert, W.; Lorman, E.; Scarpine, V.; Ross, M.C.; Sebek, J.; Straumann, T. et al.
System: The UNT Digital Library
Update on Mechanical Analysis of Monolithic Fuel Plates (open access)

Update on Mechanical Analysis of Monolithic Fuel Plates

Results on the relative bond strength of the fuel-clad interface in monolithic fuel plates have been presented at previous RRFM conferences. An understanding of mechanical properties of the fuel, cladding, and fuel / cladding interface has been identified as an important area of investigation and quantification for qualification of monolithic fuel forms. Significant progress has been made in the area of mechanical analysis of the monolithic fuel plates, including mechanical property determination of fuel foils, cladding processed by both hot isostatic pressing and friction bonding, and the fuel-clad composite. In addition, mechanical analysis of fabrication induced residual stress has been initiated, along with a study to address how such stress can be relieved prior to irradiation. Results of destructive examinations and mechanical tests are presented along with analysis and supporting conclusions. A brief discussion of alternative non-destructive evaluation techniques to quantify not only bond quality, but also bond integrity and strength, will also be provided. These are all necessary steps to link out-of-pile observations as a function of fabrication with in-pile behaviours.
Date: March 1, 2008
Creator: Burkes, D. E.; Rice, F. J.; Jue, J.-F. & Hallinan, N. P.
System: The UNT Digital Library
Citric Acid-Modified Fenton's Reaction for the Oxidation of Chlorinated Ethylenes in Soil Solution Systems (open access)

Citric Acid-Modified Fenton's Reaction for the Oxidation of Chlorinated Ethylenes in Soil Solution Systems

Fenton's reagent, a solution of hydrogen peroxide and ferrous iron catalyst, is used for an in-situ chemical oxidation of organic contaminants. Sulfuric acid is commonly used to create an acidic condition needed for catalytic oxidation. Fenton's reaction often involves pressure buildup and precipitation of reaction products, which can cause safety hazards and diminish efficiency. We selected citric acid, a food-grade substance, as an acidifying agent to evaluate its efficiencies for organic contaminant removal in Fenton's reaction, and examined the impacts of using citric acid on the unwanted reaction products. A series of batch and column experiments were performed with varying H{sub 2}O{sub 2} concentrations to decompose selected chlorinated ethylenes. Either dissolved iron from soil or iron sulfate salt was added to provide the iron catalyst in the batch tests. Batch experiments revealed that both citric and sulfuric acid systems achieved over 90% contaminant removal rates, and the presence of iron catalyst was essential for effective decontamination. Batch tests with citric acid showed no signs of pressure accumulation and solid precipitations, however the results suggested that an excessive usage of H{sub 2}O{sub 2} relative to iron catalysts (Fe{sup 2+}/H{sub 2}O{sub 2} < 1/330) would result in lowering the efficiency of contaminant …
Date: March 15, 2008
Creator: Seol, Yongkoo & Javandel, Iraj
System: The UNT Digital Library
Application of a pilot control banding tool for risk level assessment and control of nanoparticle exposures (open access)

Application of a pilot control banding tool for risk level assessment and control of nanoparticle exposures

Control Banding (CB) strategies offer simplified solutions for controlling worker exposures to constituents that are found in the workplace in the absence of firm toxicological and exposure data. These strategies may be particularly useful in nanotechnology applications, considering the overwhelming level of uncertainty over what nanomaterials and nanotechnologies present as potential work-related health risks, what about these materials might lead to adverse toxicological activity, how risk related to these might be assessed, and how to manage these issues in the absence of this information. This study introduces a pilot CB tool or 'CB Nanotool' that was developed specifically for characterizing the health aspects of working with engineered nanoparticles and determining the level of risk and associated controls for five ongoing nanotechnology-related operations being conducted at two Department of Energy (DOE) research laboratories. Based on the application of the CB Nanotool, four of the five operations evaluated in this study were found to have implemented controls consistent with what was recommended by the CB Nanotool, with one operation even exceeding the required controls for that activity. The one remaining operation was determined to require an upgrade in controls. By developing this dynamic CB Nanotool within the realm of the scientific information …
Date: March 3, 2008
Creator: Paik, S Y; Zalk, D M & Swuste, P
System: The UNT Digital Library
FRMAC Mission Analysis: What is it, and why is it useful? (open access)

FRMAC Mission Analysis: What is it, and why is it useful?

In 2002, the Director of the U.S. Department of Energy's (DOE's) National Nuclear Security Administration, Division of Emergency Response, requested a team of DOE scientists, considered experts in the field of radiological consequence management, assemble and construct a mission analysis upon which the DOE could build its response program and plan for future requirements. The team developed five scenarios upon which to build the data quality objectives (DQOs) that they considered necessary to ensure a comprehensive consequence management response from the DOE perspective. The resulting document was called the Consequence Management Mission Analysis. Based upon the positive reaction to this document and its obvious benefit to the Consequence Management mission, it was decided to expand the scope of the document to cover a mission analysis of the entire Federal Radiological Monitoring and Assessment Center (FRMAC) mission. The documentation team was expanded to include representatives from all signatories to the National Response Plan who have a role in responding to radiological emergencies. The scope of the FRMAC Mission Analysis includes all federal response resources which are activated to provide rapid support to affected state and local governments in the form of radiological monitoring and dose assessment activities at the incident site. …
Date: March 1, 2008
Creator: Hopkins, Rhonda
System: The UNT Digital Library
Basalt weathering rates on Earth and the duration of liquid water on the plains of Gusev Crater, Mars (open access)

Basalt weathering rates on Earth and the duration of liquid water on the plains of Gusev Crater, Mars

Where Martian rocks have been exposed to liquid water, chemistry versus depth profiles could elucidate both Martian climate history and potential for life. The persistence of primary minerals in weathered profiles constrains the exposure time to liquid water: on Earth, mineral persistence times range from {approx}10 ka (olivine) to {approx}250 ka (glass) to {approx}1Ma (pyroxene) to {approx}5Ma (plagioclase). Such persistence times suggest mineral persistence minima on Mars. However, Martian solutions may have been more acidic than on Earth. Relative mineral weathering rates observed for basalt in Svalbard (Norway) and Costa Rica demonstrate that laboratory pH trends can be used to estimate exposure to liquid water both qualitatively (mineral absence or presence) and quantitatively (using reactive transport models). Qualitatively, if the Martian solution pH > {approx}2, glass should persist longer than olivine; therefore, persistence of glass may be a pH-indicator. With evidence for the pH of weathering, the reactive transport code CrunchFlow can quantitatively calculate the minimum duration of exposure to liquid water consistent with a chemical profile. For the profile measured on the surface of Humphrey in Gusev Crater, the minimum exposure time is 22 ka. If correct, this estimate is consistent with short-term, episodic alteration accompanied by ongoing surface …
Date: March 15, 2008
Creator: Steefel, Carl; Hausrath, E. M.; Navarre-Sitchler, A. K.; Sak, P. B.; Steefel, C. & Brantley, S. L.
System: The UNT Digital Library
Cfd Modeling Analysis of Mechanical Draft Cooling Tower (open access)

Cfd Modeling Analysis of Mechanical Draft Cooling Tower

Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has a MDCT consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to conduct a parametric study for cooling tower performance under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model to achieve the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of the modeling calculations was performed to investigate the impact of ambient and operating conditions on the thermal performance of the cooling tower when fans …
Date: March 3, 2008
Creator: Lee, S.; Alfred Garrett, A.; James02 Bollinger, J. & Larry Koffman, L.
System: The UNT Digital Library
Molecular analysis of the gut microbiota of identical twins with Crohn's disease (open access)

Molecular analysis of the gut microbiota of identical twins with Crohn's disease

Increasing evidence suggests that a combination of host genetics and the composition of the gut microbiota are important for development of Crohn's disease (CD). Our aim was to study identical twins with CD to determine microbial factors independently of host genetics. Fecal samples were studied from 10 monozygotic twin pairs with CD (discordant n=6, concordant n=4) and 8 healthy twin pairs. DNA was extracted, 16S rRNA genes were PCR amplified and T-RFLP fingerprints generated using general bacterial and Bacteroides group specific primers. The microbial communities were also profiled based on their % G+C contents. Bacteroides 16S rRNA genes were cloned and sequenced from a subset of the samples. The bacterial diversity in each sample and similarity indices between samples were estimated based on the T-RFLP data using a combination of statistical approaches. Healthy individuals had a significantly higher bacterial diversity compared to individuals with CD. The fecal microbial communities were more similar between healthy twins than between twins with CD, especially when these were discordant for the disease. The microbial community profiles of individuals with ileal CD were significantly different from healthy individuals and those with colonic CD. Also, CD individuals had a lower relative abundance of B. uniformis and …
Date: March 14, 2008
Creator: Jansson, Janet; Dicksved, Johan; Halfvarson, Jonas; Rosenquist, Magnus; Jarnerot, Gunnar; Tysk, Curt et al.
System: The UNT Digital Library
Measurement of the ratio of the p anti-p ---> W+c-jet cross section to the inclusive p anti-p ---> W+jets cross section (open access)

Measurement of the ratio of the p anti-p ---> W+c-jet cross section to the inclusive p anti-p ---> W+jets cross section

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Date: March 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
System: The UNT Digital Library
Si Memory Chip as a Sensitive Neutron Detector (open access)

Si Memory Chip as a Sensitive Neutron Detector

A novel neutron detector is based on semiconductor technology. A boron-containing film is an integral part of the semiconductor device and is in physical contact with the charge-storage medium (CSM). The CSM is a proprietary cell design known as MirrorBit{trademark}, which is different from conventional memory designs such as SRAM or DRAM. The design doubles the resolution and sensitivity in the array. This enables a highly effective detection of the secondary particles, {sup 7}Li and {sup 4}He, produced due to neutron capture by {sup 10}B in the device. Other approaches using semiconductor materials for neutron detection have employed single-diode detectors that require off-system preamplifiers to filter and condition the signal. There are several advantages to this non-volatile detector, one being that it requires no power for detection and retains the signal until reset. Further, this detector, a semiconductor chip, can be seamlessly integrated into other systems. Finally, the semiconductor manufacturing process on which the detector is based will allow for a high-volume and low-cost alternative to current detectors. MirrorBit{trademark} chips were exposed to neutron flux and the signals recorded. Detailed results from this experiment will be described in this presentation.
Date: March 1, 2008
Creator: Quam, William
System: The UNT Digital Library
Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 2. Overview). (open access)

Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 2. Overview).

The objectives of this report are: (1) Investigate the catalysis of water oxidation by cobalt and manganese hydrous oxides immobilized on titania or silica nanoparticles, and dinuclear metal complexes with quinonoid ligands in order to develop a better understanding of the critical water oxidation chemistry, and rationally search for improved catalysts. (2) Optimize the light-harvesting and charge-separation abilities of stable semiconductors including both a focused effort to improve the best existing materials by investigating their structural and electronic properties using a full suite of characterization tools, and a parallel effort to discover and characterize new materials. (3) Combine these elements to examine the function of oxidation catalysts on Band-Gap-Narrowed Semiconductor (BGNSC) surfaces and elucidate the core scientific challenges to the efficient coupling of the materials functions.
Date: March 18, 2008
Creator: Fujita, E.; Khalifah, P.; Lymar, S.; Muckerman, J. T. & Rodriguez, J.
System: The UNT Digital Library
Models of Longitudinal Space-Charge Impedance for the Study of theMicrobunching Instability (open access)

Models of Longitudinal Space-Charge Impedance for the Study of theMicrobunching Instability

A 1D model of space-charge impedance, assuming atransversely uniform beam with circular cross-section, has been proposedand is being extensively used in the modelling of the microbunchinginstability of relevance for the beam delivery systems of x-ray FELs. Inthis paper we investigate the limitation of the model when applied tostudying the effect of shot noise--one of the sources of themicrobunching instability. We make comparison witha fully 3D calculationand identify the upper end of the frequency spectrum for applicability ofthe 1D model. Relaxation of the assumptions regarding axis-symmetry anduniformity of the transverse density is also reviewed.
Date: March 10, 2008
Creator: Venturini, Marco
System: The UNT Digital Library
Active Damping of the E-P Instability at the Los Alamos Proton Storage Ring (open access)

Active Damping of the E-P Instability at the Los Alamos Proton Storage Ring

A prototype of an analog, transverse (vertical) feedback system for active damping of the two-stream (e-p) instability has been developed and successfully tested at the Los Alamos Proton Storage Ring (PSR). This system was able to improve the instability threshold by approximately 30% (as measured by the change in RF buncher voltage at instability threshold). The feedback system configuration, setup procedures, and optimization of performance are described. Results of several experimental tests of system performance are presented including observations of instability threshold improvement and grow-damp experiments, which yield estimates of instability growth and damping rates. A major effort was undertaken to identify and study several factors limiting system performance. Evidence obtained from these tests suggests that performance of the prototype was limited by higher instability growth rates arising from beam leakage into the gap at lower RF buncher voltage and the onset of instability in the horizontal plane, which had no feedback.
Date: March 17, 2008
Creator: Macek, R. J.; Assadi, S.; Byrd, J. M.; Deibele, C. E.; Henderson, S. D.; Lee, S. Y. et al.
System: The UNT Digital Library
Progress to Develop an Advanced Solar-Selective Coating (open access)

Progress to Develop an Advanced Solar-Selective Coating

The progress to develop a durable advanced solar-selective coating will be described. Experimental work has focused on modeling high-temperature, solar-selective coatings; depositing the individual layers and modeled coatings; measuring the optical, thermal, morphology, and compositional properties and using the data to validate the modeled and deposited properties; re-optimizing the coating; and testing the coating performance and durability.
Date: March 1, 2008
Creator: Kennedy, C. E.
System: The UNT Digital Library
Hyperfine Quenching of the 2s2p 3P0 State of Berylliumlike Ions (open access)

Hyperfine Quenching of the 2s2p 3P0 State of Berylliumlike Ions

The hyperfine-induced 2s2p {sup 3}P{sub 0}-2s{sup 2} {sup 1}S{sub 0} transition rate for Be-like {sup 47}Ti{sup 18+} was recently measured in a storage-ring experiment by Schippers et al. [Phys. Rev. Lett. 98, 033001 (2007)]. The measured value of 0.56(3) s{sup -1} is almost 60% larger than the theoretical value of 0.356 s{sup -1} from a multiconfiguration Dirac-Fock calculation by Marques et al. [Phys. Rev. A 47, 929 (1993)]. In this work, we use a large-scale relativistic configuration-interaction method to calculate these hyperfine-induced rates for ions with Z = 6-92. Coherent hyperfine-quenching effects between the 2s2p {sup 1,3}P{sub 1} states are included in a perturbative as well as a radiation damping approach. Contrary to the claims of Marques et al., contributions from the {sup 1}P{sub 1} state are substantial and lead to a hyperfine-induced rate of 0.67 s{sup -1}, in better agreement with, though larger than, the measured value.
Date: March 13, 2008
Creator: Cheng, K T; Chen, M H & Johnson, W R
System: The UNT Digital Library
Estimating Filtering Errors Using the Peano Kernel Theorem (open access)

Estimating Filtering Errors Using the Peano Kernel Theorem

The Peano Kernel Theorem is introduced and a frequency domain derivation is given. It is demonstrated that the application of this theorem yields simple and accurate formulas for estimating the error introduced into a signal by filtering it to reduce noise.
Date: March 1, 2008
Creator: Blair, Jerome
System: The UNT Digital Library
PREDICTION OF SURFACE SETTLEMENT DUE TO THE DISPLACEMENT OF SOFT ZONES (open access)

PREDICTION OF SURFACE SETTLEMENT DUE TO THE DISPLACEMENT OF SOFT ZONES

In areas composed of coastal plain sediments, soft zones subjected to partial overburden may be present in the subsurface. During or after a seismic event, these soft zones may be compressed. The resulting displacement due to the deformation of the soft zones will propagate to the ground surface and cause the surface to settle. This paper presents a method to predict the settlement at the surface due to the propagation of the displacement from the soft zones. This method is performed by discretizing the soft zones into multiple clusters of finite sub-areas or subspaces. Settlement profile at the ground surface due to the displacement of each sub-area or subspace is computed assuming the shape is a normal distribution function. Settlement due to the displacement of the soft zones can then be approximated by adding the settlements computed for all the sub-areas or subspaces. This method provides a simple and useful tool for the prediction of the settlement profile and the results are consistent with those obtained from the finite difference analysis.
Date: March 3, 2008
Creator: Li, W
System: The UNT Digital Library
Sensitivity of Concentrating Solar Power Trough Performance, Cost and Financing with Solar Advisor Model (open access)

Sensitivity of Concentrating Solar Power Trough Performance, Cost and Financing with Solar Advisor Model

A comprehensive solar technology systems analysis model, the Solar Advisor Model (SAM) was developed to support the federal R&D community and the solar industry. This model, developed by staff at NREL and Sandia National Laboratory, is able to model the costs, finances, and performance of concentrating solar power and photovoltaics (PV). Currently, parabolic troughs and concentrating PV are the two concentrating technologies modeled within the SAM environment.
Date: March 1, 2008
Creator: Blair, N.; Mehos, M. & Christensen, C.
System: The UNT Digital Library