100 Area D4 Project Building Completion Report - July 2007 to December 2008 (open access)

100 Area D4 Project Building Completion Report - July 2007 to December 2008

This report documents the decontamination, decommissioning, and demolition of the 105-NB, 163-N, 183-N, 183-NA, 183-NB, 183-NC, 184-N, 184-NA, 184-NB, 184-NC, 184-ND, 184-NE, 184-NF, 1312-N, 1330-N, 1705-N, 1705-NA, 1706-N, 1712-N, 1714-N, 1714-NA, 1714-NB, 1802-N, MO-050, MO-055, MO-358, MO-390, MO-900, MO-911, and MO-950 facilities in the 100 Area of the Hanford Site. The D4 activities for these facilities include utility disconnection, planning, characterization, engineering, removal of hazardous and radiological contaminated materials, equipment removal, decommissioning, deactivation, decontamination, demolition of the structure, and removal of the remaining slabs.
Date: April 15, 2009
Creator: Stankovich, M. T.
Object Type: Report
System: The UNT Digital Library
ASSESSMENT OF HOUSEHOLD CARBON FOOTPRINT REDUCTION POTENTIALS (open access)

ASSESSMENT OF HOUSEHOLD CARBON FOOTPRINT REDUCTION POTENTIALS

The term ?household carbon footprint? refers to the total annual carbon emissions associated with household consumption of energy, goods, and services. In this project, Lawrence Berkeley National Laboratory developed a carbon footprint modeling framework that characterizes the key underlying technologies and processes that contribute to household carbon footprints in California and the United States. The approach breaks down the carbon footprint by 35 different household fuel end uses and 32 different supply chain fuel end uses. This level of end use detail allows energy and policy analysts to better understand the underlying technologies and processes contributing to the carbon footprint of California households. The modeling framework was applied to estimate the annual home energy and supply chain carbon footprints of a prototypical California household. A preliminary assessment of parameter uncertainty associated with key model input data was also conducted. To illustrate the policy-relevance of this modeling framework, a case study was conducted that analyzed the achievable carbon footprint reductions associated with the adoption of energy efficient household and supply chain technologies.
Date: April 15, 2009
Creator: Kramer, Klaas Jan; Homan, Greg; Brown, Rich; Worrell, Ernst & Masanet, Eric
Object Type: Report
System: The UNT Digital Library
Country Report on Building Energy Codes in China (open access)

Country Report on Building Energy Codes in China

This report is part of a series of reports on building energy efficiency codes in countries associated with the Asian Pacific Partnership (APP) - Australia, South Korea, Japan, China, India, and the United States of America (U.S.). This reports gives an overview of the development of building energy codes in China, including national energy policies related to building energy codes, history of building energy codes, recent national projects and activities to promote building energy codes. The report also provides a review of current building energy codes (such as building envelope and HVAC) for commercial and residential buildings in China.
Date: April 15, 2009
Creator: Shui, Bin; Evans, Meredydd; Lin, H.; Jiang, Wei; Liu, Bing; Song, Bo et al.
Object Type: Report
System: The UNT Digital Library
Country Report on Building Energy Codes in Japan (open access)

Country Report on Building Energy Codes in Japan

This report is part of a series of reports on building energy efficiency codes in countries associated with the Asian Pacific Partnership (APP) - Australia, South Korea, Japan, China, India, and the United States of America (U.S.). This reports gives an overview of the development of building energy codes in Japan, including national energy policies related to building energy codes, history of building energy codes, recent national projects and activities to promote building energy codes. The report also provides a review of current building energy codes (such as building envelope, HVAC, and lighting) for commercial and residential buildings in Japan.
Date: April 15, 2009
Creator: Evans, Meredydd; Shui, Bin & Takagi, T.
Object Type: Report
System: The UNT Digital Library
Development of a Progeny Marker for Steelhead; A Thesis submitted to Oregon State University. (open access)

Development of a Progeny Marker for Steelhead; A Thesis submitted to Oregon State University.

This study was undertaken to determine if strontium chloride could be used to create a trans-generational otolith mark in steelhead (Oncorhynchus mykiss). I completed two strontium injection trials and a survey of juvenile steelhead from various steelhead hatcheries. The two trials measured Sr:Ca ratios in otoliths in response to injections and the survey measured the natural variation in Sr:Ca ratios in otoliths of juvenile hatchery steelhead in response to the natural variation. In 2003, adult female Wallowa River, Oregon O. mykiss, were captured at the hatchery and evenly divided between a control group and two treatment groups. These females received an intraperitoneal injection of 1cc/500 g of body weight of a physiologically isotonic solution (0.9% saline) containing concentrations of 0 (control), 1000, or 5000 parts per million (ppm) of strontium chloride hexahydrate (SrCl{sub 2}* 6H{sub 2}O). Females were housed in a single outdoor tank until spawned artificially, and a distinct external tag identified each female within each treatment group. In 2004, female steelhead were captured throughout the duration of the adult returns to the Umatilla River basin and injected with 0, 1000, 5000, or 20,000-ppm strontium. In both trials, progeny of fish treated with strontium had significantly higher Sr:Ca ratios …
Date: April 15, 2009
Creator: Shippentower, Gene E.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Energy dependence of transverse momentum fluctuations in Pb+Pb collisions at the CERN Super Proton Synchrotron (SPS) at 20A to 158A GeV (open access)

Energy dependence of transverse momentum fluctuations in Pb+Pb collisions at the CERN Super Proton Synchrotron (SPS) at 20A to 158A GeV

Results are presented on event-by-event fluctuations of transverse momenta p{sub T} in central Pb+Pb interactions at 20A, 30A, 40A, 80A, and 158A GeV. The analysis was performed for charged particles at forward center-of-mass rapidity (1.1 < y*{sub {pi}} < 2.6). Three fluctuation measures were studied: the distribution of average transverse momentum M(p{sub T}) in the event, the {phi}{sub p{sub T}} fluctuation measure, and two-particle transverse momentum correlations. Fluctuations of p{sub T} are small and show no significant energy dependence in the energy range of the CERN Super Proton Synchrotron. Results are compared with QCD-inspired predictions for the critical point, and with the UrQMD model. Transverse momentum fluctuations, similar to multiplicity fluctuations, do not show the increase expected for freeze-out near the critical point of QCD.
Date: April 15, 2009
Creator: Collaboration, NA49 & Anticic, T.
Object Type: Article
System: The UNT Digital Library
Environmental Management Waste Management Facility Waste Lot Profile for the K-770 Scrap Yard Soils and Miscellaneous Debris, East Tennessee Technology Park, Oak Ridge, Tennessee - EMWMF Waste Lot 4.12 (open access)

Environmental Management Waste Management Facility Waste Lot Profile for the K-770 Scrap Yard Soils and Miscellaneous Debris, East Tennessee Technology Park, Oak Ridge, Tennessee - EMWMF Waste Lot 4.12

Waste Lot 4.12 consists of approximately 17,500 yd{sup 3} of low-level, radioactively contaminated soil, concrete, and incidental metal and debris generated from remedial actions at the K-770 Scrap Metal Yard and Contaminated Debris Site (the K-770 Scrap Yard) at the East Tennessee Technology Park (ETTP). The excavated soil will be transported by dump truck to the Environmental Management Waste Management Facility (EMWMF). This profile provides project-specific information to demonstrate compliance with Attainment Plan for Risk/Toxicity-based Waste Acceptance Criteria at the Oak Ridge Reservation, Oak Ridge, Tennessee (DOE 2001). The K-770 Scrap Yard is an approximately 36-acre storage area located southwest of the main portion of ETTP, outside the security perimeter fence in the Powerhouse Area adjacent to the Clinch River. The K-770 area was used to store radioactively contaminated or suspected contaminated materials during and previous to the K-25 Site cascade upgrading program. The waste storage facility began operation in the 1960s and is estimated to at one time contain in excess of 40,000 tons of low-level, radioactively contaminated scrap metal. Scrap metal was taken to the site when it was found to contain alpha or beta/gamma activity on the surface or if the scrap metal originated from a process …
Date: April 15, 2009
Creator: M., Davenport
Object Type: Report
System: The UNT Digital Library
Feedbacks between hydrological heterogeneity and bioremediation induced biogeochemical transformations (open access)

Feedbacks between hydrological heterogeneity and bioremediation induced biogeochemical transformations

For guiding optimal design and interpretation of in-situ treatments that strongly perturb subsurface systems, knowledge about the spatial and temporal patterns of mass transport and reaction intensities are important. Here, a procedure was developed and applied to time-lapse concentrations of a conservative tracer (bromide), an injected amendment (acetate) and reactive species (iron(II), uranium(VI) and sulfate) associated with two field scale biostimulation experiments, which were conducted successively at the same field location over two years. The procedure is based on a temporal moment analysis approach that relies on a streamtube approximation. The study shows that biostimulated reactions can be considerably influenced by subsurface hydrological and geochemical heterogeneities: the delivery of bromide and acetate and the intensity of the sulfate reduction is interpreted to be predominantly driven by the hydrological heterogeneity, while the intensity of the iron reduction is interpreted to be primarily controlled by the geochemical heterogeneity. The intensity of the uranium(VI) reduction appears to be impacted by both the hydrological and geochemical heterogeneity. Finally, the study documents the existence of feedbacks between hydrological heterogeneity and remediation-induced biogeochemical transformations at the field scale, particularly the development of precipitates that may cause clogging and flow rerouting.
Date: April 15, 2009
Creator: Englert, A.; Hubbard, S. S.; Williams, K. H.; Li, L. & Steefel, C. I.
Object Type: Article
System: The UNT Digital Library
GLOVEBOX WINDOWS, FIRE PROTECTION AND VOICES FROM THE PAST (open access)

GLOVEBOX WINDOWS, FIRE PROTECTION AND VOICES FROM THE PAST

'Study the past--what is past is prologue'. These words appear as the motto on a pair of statues at the National Archives Building in Washington DC. They are also the opening sentence in the preface of a document written in August of 1956 entitled 'A Summary of Accidents and Incidents Involving Radiation in Atomic Energy Activities--June 1945 thru December 1955'. This document, one of several written by D.F. Hayes of the Safety and Fire Protection Branch, Division of Organization and Personnel, U.S. Atomic Energy Commission in Washington DC, and many others are often forgotten even though they contain valuable glovebox fire protection lessons for us today.
Date: April 15, 2009
Creator: Till, W
Object Type: Article
System: The UNT Digital Library
HYBRID SULFUR ELECTROLYZER DEVELOPMENT FY09 SECOND QUARTER REPORT (open access)

HYBRID SULFUR ELECTROLYZER DEVELOPMENT FY09 SECOND QUARTER REPORT

The primary objective of the DOE-NE Nuclear Hydrogen Initiative (NHI) is to develop the nuclear hydrogen production technologies necessary to produce hydrogen at a cost competitive with other alternative transportation fuels. The focus of the NHI is on thermochemical cycles and high temperature electrolysis that can be powered by heat from high temperature gas reactors. The Savannah River National Laboratory (SRNL) has been tasked with the primary responsibility to perform research and development in order to characterize, evaluate and develop the Hybrid Sulfur (HyS) thermochemical process. This report documents work during the first quarter of Fiscal Year 2009, for the period between January 1, 2009 and March 31, 2009. The HyS Process is a two-step hybrid thermochemical cycle that is part of the 'Sulfur Family' of cycles. As a sulfur cycle, it uses high temperature thermal decomposition of sulfuric acid to produce oxygen and to regenerate the sulfur dioxide reactant. The second step of the process uses a sulfur dioxide depolarized electrolyzer (SDE) to split water and produce hydrogen by electrochemically reacting sulfur dioxide with H{sub 2}O. The SDE produces sulfuric acid, which is then sent to the acid decomposer to complete the cycle. The DOE NHI program is developing …
Date: April 15, 2009
Creator: Herman, D; David Hobbs, D; Hector Colon-Mercado, H; Timothy Steeper, T; John Steimke, J & Elvington, Mark C.
Object Type: Report
System: The UNT Digital Library
New Berkeley Lab Report Tracks a Decade of PV Installed Cost Trends (open access)

New Berkeley Lab Report Tracks a Decade of PV Installed Cost Trends

Installations of PV systems have been expanding at a rapid pace in recent years. In the United States, the market for PV is driven by national, state, and local government incentives, including upfront cash rebates, production-based incentives, requirements that electricity suppliers purchase a certain amount of solar energy, and Federal and state tax benefits. These programs are, in part, motivated by the popular appeal of solar energy and by the positive attributes of PV - e.g., modest environmental impacts, avoidance of fuel price risks, coincidence with peak electrical demand, and the location of PV at the point of use. Given the relatively high cost of PV, however, a key goal of these policies is to encourage cost reductions over time. Therefore, as policy incentives have become more significant and as PV deployment has accelerated, so too has the desire to track the installed cost of PV systems over time, by system characteristics, by system location, and by component. A new Lawrence Berkeley National Laboratory report, 'Tracking the Sun: The Installed Cost of Photovoltaics in the U.S. from 1998-2007', helps to fill this need by summarizing trends in the installed cost (i.e., the cost paid by the system owner) of grid-connected …
Date: April 15, 2009
Creator: Barbose, Galen; Peterman, Carla & Wiser, Ryan
Object Type: Article
System: The UNT Digital Library
Numerical investigation for the impact of CO2 geologic sequestration on regional groundwater flow (open access)

Numerical investigation for the impact of CO2 geologic sequestration on regional groundwater flow

Large-scale storage of carbon dioxide in saline aquifers may cause considerable pressure perturbation and brine migration in deep rock formations, which may have a significant influence on the regional groundwater system. With the help of parallel computing techniques, we conducted a comprehensive, large-scale numerical simulation of CO{sub 2} geologic storage that predicts not only CO{sub 2} migration, but also its impact on regional groundwater flow. As a case study, a hypothetical industrial-scale CO{sub 2} injection in Tokyo Bay, which is surrounded by the most heavily industrialized area in Japan, was considered, and the impact of CO{sub 2} injection on near-surface aquifers was investigated, assuming relatively high seal-layer permeability (higher than 10 microdarcy). A regional hydrogeological model with an area of about 60 km x 70 km around Tokyo Bay was discretized into about 10 million gridblocks. To solve the high-resolution model efficiently, we used a parallelized multiphase flow simulator TOUGH2-MP/ECO2N on a world-class high performance supercomputer in Japan, the Earth Simulator. In this simulation, CO{sub 2} was injected into a storage aquifer at about 1 km depth under Tokyo Bay from 10 wells, at a total rate of 10 million tons/year for 100 years. Through the model, we can examine …
Date: April 15, 2009
Creator: Yamamoto, H.; Zhang, K.; Karasaki, K.; Marui, A.; Uehara, H. & Nishikawa, N.
Object Type: Article
System: The UNT Digital Library
Physics and Chemistry of the Interiors of Large Planets: A new generation of condensed matter using NIF (open access)

Physics and Chemistry of the Interiors of Large Planets: A new generation of condensed matter using NIF

None
Date: April 15, 2009
Creator: Collins, G.
Object Type: Report
System: The UNT Digital Library
Production of the Smallest QED Atom: True Muonium (open access)

Production of the Smallest QED Atom: True Muonium

The 'true muonium' ({mu}{sup +}{mu}{sup -}) and 'true tauonium' ({tau}{sup +}{tau}{sup -}) bound states are not only the heaviest, but also the most compact pure QED systems. The rapid weak decay of the {tau} makes the observation of true tauonium difficult. However, as we show, the production and study of true muonium is possible at modern electron-positron colliders.
Date: April 15, 2009
Creator: Brodsky, Stanley J. & Lebed, Richard F.
Object Type: Article
System: The UNT Digital Library
RADIOLYTIC HYDROGEN GENERATION INSAVANNAH RIVER SITE (SRS) HIGH LEVEL WASTETANKS COMPARISON OF SRS AND HANFORDMODELING PREDICTIONS (open access)

RADIOLYTIC HYDROGEN GENERATION INSAVANNAH RIVER SITE (SRS) HIGH LEVEL WASTETANKS COMPARISON OF SRS AND HANFORDMODELING PREDICTIONS

In the high level waste tanks at the Savannah River Site (SRS), hydrogen is produced continuously by interaction of the radiation in the tank with water in the waste. Consequently, the vapor spaces of the tanks are purged to prevent the accumulation of H{sub 2} and possible formation of a flammable mixture in a tank. Personnel at SRS have developed an empirical model to predict the rate of H{sub 2} formation in a tank. The basis of this model is the prediction of the G value for H{sub 2} production. This G value is the number of H{sub 2} molecules produced per 100 eV of radiolytic energy absorbed by the waste. Based on experimental studies it was found that the G value for H{sub 2} production from beta radiation and from gamma radiation were essentially equal. The G value for H{sub 2} production from alpha radiation was somewhat higher. Thus, the model has two equations, one for beta/gamma radiation and one for alpha radiation. Experimental studies have also indicated that both G values are decreased by the presence of nitrate and nitrite ions in the waste. These are the main scavengers for the precursors of H{sub 2} in the waste; …
Date: April 15, 2009
Creator: Crawford, C & Ned Bibler, N
Object Type: Report
System: The UNT Digital Library
Reactivity of Au nanoparticles supported over SiO2 and TiO2 studiedby ambient pressure photoelectron spectroscopy (open access)

Reactivity of Au nanoparticles supported over SiO2 and TiO2 studiedby ambient pressure photoelectron spectroscopy

The influence of the metal cluster size and the identity of the support on the reactivity of gold based catalysts have been studied in the CO oxidation reaction. To overcome the structural complexity of the supported catalysts, gold nanoparticles synthesized from colloidal chemistry with precisely controlled size have been used. Those particles were supported over SiO{sub 2} and TiO{sub 2} and their catalytic activity was measured in a flow reactor. The reaction rate was dependent on the particle size and the support, suggesting two reaction pathways in the CO oxidation reaction. In parallel, ambient pressure photoelectron spectroscopy (APPS) has been performed under reaction conditions using bidimensional model catalysts prepared upon supporting the Au nanoparticles over planar polycrystalline SiO{sub 2} and TiO{sub 2} thin films by means of the Langmuir-Blodgett (LB) technique to mimic the characteristic of the powder samples. In this way, the catalytically active surface was characterized under true reaction conditions, revealing that during CO oxidation gold remains in the metallic state.
Date: April 15, 2009
Creator: Herranz, Tirma; Deng, Xingyi; Cabot, Andreu; Alivisatos, Paul; Liu, Zhi; Soler-Illia, Galo et al.
Object Type: Article
System: The UNT Digital Library
Resonant seismic emission of subsurface objects (open access)

Resonant seismic emission of subsurface objects

Numerical modeling results and field data indicate that some contrasting subsurface objects (such as tunnels, caves, pipes, filled pits, and fluid-filled fractures) are capable of generating durable resonant oscillations after trapping seismic energy. These oscillations consist of surface types of circumferential waves that repeatedly propagate around the object. The resonant emission of such trapped energy occurs primarily in the form of shear body waves that can be detected by remotely placed receivers. Resonant emission reveals itself in the form of sharp resonant peaks for the late parts of the records, when all strong direct and primary reflected waves are gone. These peaks were observed in field data for a buried barrel filled with water, in 2D finite-difference modeling results, and in the exact canonical solution for a fluid-filled sphere. A computed animation for the diffraction of a plane wave upon a low-velocity elastic sphere confirms the generation of resonances by durable surface waves. Resonant emission has characteristic quasi-hyperbolic traveltime patterns on shot gathers. The inversion of these patterns can be performed in the frequency domain after muting the strong direct and primary scattered waves. Subsurface objects can be detected and imaged at a single resonance frequency without an accurate knowledge …
Date: April 15, 2009
Creator: Korneev, Valeri A.
Object Type: Article
System: The UNT Digital Library
The Slow:Fast substitution ratio reveals changing patterns of natural selection in gamma-proteobacterial genomes (open access)

The Slow:Fast substitution ratio reveals changing patterns of natural selection in gamma-proteobacterial genomes

Different microbial species are thought to occupy distinct ecological niches, subjecting each species to unique selective constraints, which may leave a recognizable signal in their genomes. Thus, it may be possible to extract insight into the genetic basis of ecological differences among lineages by identifying unusual patterns of substitutions in orthologous gene or protein sequences. We use the ratio of substitutions in slow versus fast-evolving sites (nucleotides in DNA, or amino acids in protein sequence) to quantify deviations from the typical pattern of selective constraint observed across bacterial lineages. We propose that elevated S:F in one branch (an excess of slow-site substitutions) can indicate a functionally-relevant change, due to either positive selection or relaxed evolutionary constraint. In a genome-wide comparative study of gamma-proteobacterial proteins, we find that cell-surface proteins involved with motility and secretion functions often have high S:F ratios, while information-processing genes do not. Change in evolutionary constraints in some species is evidenced by increased S:F ratios within functionally-related sets of genes (e.g., energy production in Pseudomonas fluorescens), while other species apparently evolve mostly by drift (e.g., uniformly elevated S:F across most genes in Buchnera spp.). Overall, S:F reveals several species-specific, protein-level changes with potential functional/ecological importance. As microbial …
Date: April 15, 2009
Creator: Alm, Eric & Shapiro, B. Jesse
Object Type: Article
System: The UNT Digital Library
South Fork Salmon River Watershed Restoration, 2008-2009 Annual Report. (open access)

South Fork Salmon River Watershed Restoration, 2008-2009 Annual Report.

The watershed restoration work elements within the project area, the South Fork Salmon River Watershed, follow the watershed restoration approach adopted by the Nez Perce Tribe Department of Fisheries Resource Management (DFRM) - Watershed Division. The vision of the Nez Perce Tribe DFRM-Watershed Division focuses on protecting, restoring, and enhancing watersheds and treaty resources within the ceded territory of the Nez Perce Tribe under the Treaty of 1855 with the United States Federal Government. The program uses a holistic approach, which encompasses entire watersheds, ridge top to ridge top, emphasizing all cultural aspects and strategies that rely on natural fish production and healthy river ecosystems. The Nez Perce Tribe DFRM-Watershed Division strives towards maximizing historic ecosystem productivity and health for the restoration of anadromous and resident fish populations and the habitat on which all depend on for future generations Originally, this project was funded to create a step/pool stream channel that was appropriate to restore fish passage where the 'Glory Hole Cascade' is currently located at the Stibnite Mine. Due to unforeseen circumstances at the time, the project is unable to move forward as planned and a request for a change in scope of the project and an expansion of …
Date: April 15, 2009
Creator: Reaney, Mark D.
Object Type: Report
System: The UNT Digital Library
A state-space Bayesian framework for estimating biogeochemical transformations using time-lapse geophysical data (open access)

A state-space Bayesian framework for estimating biogeochemical transformations using time-lapse geophysical data

We develop a state-space Bayesian framework to combine time-lapse geophysical data with other types of information for quantitative estimation of biogeochemical parameters during bioremediation. We consider characteristics of end-products of biogeochemical transformations as state vectors, which evolve under constraints of local environments through evolution equations, and consider time-lapse geophysical data as available observations, which could be linked to the state vectors through petrophysical models. We estimate the state vectors and their associated unknown parameters over time using Markov chain Monte Carlo sampling methods. To demonstrate the use of the state-space approach, we apply it to complex resistivity data collected during laboratory column biostimulation experiments that were poised to precipitate iron and zinc sulfides during sulfate reduction. We develop a petrophysical model based on sphere-shaped cells to link the sulfide precipitate properties to the time-lapse geophysical attributes and estimate volume fraction of the sulfide precipitates, fraction of the dispersed, sulfide-encrusted cells, mean radius of the aggregated clusters, and permeability over the course of the experiments. Results of the case study suggest that the developed state-space approach permits the use of geophysical datasets for providing quantitative estimates of end-product characteristics and hydrological feedbacks associated with biogeochemical transformations. Although tested here on laboratory …
Date: April 15, 2009
Creator: Chen, J.; Hubbard, S.; Williams, K.; Pride, S.; Li, L.; Steefel, C. et al.
Object Type: Article
System: The UNT Digital Library
The Study and Implementation of Electrically Small Printed Antennas for an Integrated Transceiver Design (open access)

The Study and Implementation of Electrically Small Printed Antennas for an Integrated Transceiver Design

This work focuses on the design and evaluation of the inverted-F, meandering-monopole, and loop antenna geometries. These printed antennas are studied with the goal of identifying which is suitable for use in a miniaturized transceiver design and which has the ability to provide superior performance using minimal Printed Circuit Board (PCB) space. As a result, the main objective is to characterize tradeoffs and identify which antenna provides the best compromise among volume, bandwidth and efficiency. For experimentation purposes, three types of meandering-monopole antenna are examined resulting in five total antennas for the study. The performance of each antenna under study is evaluated based upon return loss, operational bandwidth, and radiation pattern characteristics. For our purposes, return loss is measured using the S11-port reflection coefficient which helps to characterize how well the small antenna is able to be efficiently fed. Operational bandwidth is measured as the frequency range over which the antenna maintains 2:1 Voltage Standing Wave Ratio (VSWR) or equivalently has 10-dB return loss. Ansoft High Frequency Structure Simulator (HFSS) is used to simulate expected resonant frequency, bandwidth, VSWR, and radiation pattern characteristics. Ansoft HFSS simulation is used to provide a good starting point for antenna design before actual prototype …
Date: April 15, 2009
Creator: Speer, Pete
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Tunable Tensor Voting Improves Grouping of Membrane-Bound Macromolecules (open access)

Tunable Tensor Voting Improves Grouping of Membrane-Bound Macromolecules

Membrane-bound macromolecules are responsible for structural support and mediation of cell-cell adhesion in tissues. Quantitative analysis of these macromolecules provides morphological indices for damage or loss of tissue, for example as a result of exogenous stimuli. From an optical point of view, a membrane signal may have nonuniform intensity around the cell boundary, be punctate or diffused, and may even be perceptual at certain locations along the boundary. In this paper, a method for the detection and grouping of punctate, diffuse curvilinear signals is proposed. Our work builds upon the tensor voting and the iterative voting frameworks to propose an efficient method to detect and refine perceptually interesting curvilinear structures in images. The novelty of our method lies on the idea of iteratively tuning the tensor voting fields, which allows the concentration of the votes only over areas of interest. We validate the utility of our system with synthetic and annotated real data. The effectiveness of the tunable tensor voting is demonstrated on complex phenotypic signals that are representative of membrane-bound macromolecular structures.
Date: April 15, 2009
Creator: Loss, Leandro A.; Bebis, George & Parvin, Bahram
Object Type: Article
System: The UNT Digital Library
UNCERTAINTY IN THE GLOBAL FORECAST SYSTEM (open access)

UNCERTAINTY IN THE GLOBAL FORECAST SYSTEM

We validated one year of Global Forecast System (GFS) predictions of surface meteorological variables (wind speed, air temperature, dewpoint temperature, air pressure) over the entire planet for forecasts extending from zero hours into the future (an analysis) to 36 hours. Approximately 12,000 surface stations world-wide were included in this analysis. Root-Mean-Square- Errors (RMSE) increased as the forecast period increased from zero to 36 hours, but the initial RMSE were almost as large as the 36 hour forecast RMSE for all variables. Typical RMSE were 3 C for air temperature, 2-3mb for sea-level pressure, 3.5 C for dewpoint temperature and 2.5 m/s for wind speed. Approximately 20-40% of the GFS errors can be attributed to a lack of resolution of local features. We attribute the large initial RMSE for the zero hour forecasts to the inability of the GFS to resolve local terrain features that often dominate local weather conditions, e.g., mountain- valley circulations and sea and land breezes. Since the horizontal resolution of the GFS (about 1{sup o} of latitude and longitude) prevents it from simulating these locally-driven circulations, its performance will not improve until model resolution increases by a factor of 10 or more (from about 100 km to …
Date: April 15, 2009
Creator: Werth, D. & Garrett, A.
Object Type: Article
System: The UNT Digital Library
A Year of Radiation Measurements at the North Slope of Alaska Second Quarter 2009 ARM and Climate Change Prediction Program Metric Report (open access)

A Year of Radiation Measurements at the North Slope of Alaska Second Quarter 2009 ARM and Climate Change Prediction Program Metric Report

In 2009, the Atmospheric Radiation Measurement (ARM) Program and the Climate Change Prediction Program (CCPP) have been asked to produce joint science metrics. For CCPP, the second quarter metrics are reported in Evaluation of Simulated Precipitation in CCSM3: Annual Cycle Performance Metrics at Watershed Scales. For ARM, the metrics will produce and make available new continuous time series of radiative fluxes based on one year of observations from Barrow, Alaska, during the International Polar Year and report on comparisons of observations with baseline simulations of the Community Climate System Model (CCSM).
Date: April 15, 2009
Creator: McFarlane, S. A.; Shi, Y. & Long, C. N.
Object Type: Report
System: The UNT Digital Library