Model Documentation for the MiniCAM (open access)

Model Documentation for the MiniCAM

The MiniCAM, short for the Mini-Climate Assessment Model, is an integrated assessment model of moderate complexity focused on energy and agriculture sectors. The model produces emissions of greenhouse gases (carbon dioxide, methane and nitrous oxide) and other radiatively important substances such as sulfur dioxide. Through incorporation of the simple climate model MAGICC, the consequences of these emissions for climate change and sea-level rise can be examined. The MiniCAM is designed to be fast and flexible.
Date: July 17, 2003
Creator: Brenkert, Antoinette L.; Smith, Steven J.; Kim, Son H. & Pitcher, Hugh M.
Object Type: Report
System: The UNT Digital Library
Theoretical Progress for the Associated Production of a Higgs Boson With Heavy Quarks at Hadron Colliders. (open access)

Theoretical Progress for the Associated Production of a Higgs Boson With Heavy Quarks at Hadron Colliders.

The production of a Higgs boson in association with a pair of t{bar t} or b{bar b} quarks plays a very important role at both the Tevatron and the Large Hadron Collider. The theoretical prediction of the corresponding cross sections has been improved by including the complete next-to-leading order QCD corrections. After a brief introduction, we review the results obtained for both the Tevatron and the Large Hadron Collider.
Date: July 17, 2003
Creator: Dawson, S.; Jackson, C. B.; Orr, L. H.; Reina, L. & Wackeroth, D.
Object Type: Article
System: The UNT Digital Library
Moment Magnitude Calibration for the Eastern Mediterranean Region from Broadband Regional Coda Envelopes (open access)

Moment Magnitude Calibration for the Eastern Mediterranean Region from Broadband Regional Coda Envelopes

The following is an overview of results from ROA01-32 that focuses on an empirical method of calibrating stable seismic source moment-rate spectra derived from regional coda envelopes using broadband stations. The main goal was to develop a regional magnitude methodology that had the following properties: (1) it is tied to an absolute scale and is thus unbiased and transportable; (2) it can be tied seamlessly to the well-established teleseismic and regional catalogs; (3) it is applicable to small events using a sparse network of regional stations; (4) it is flexible enough to utilize S{sub n}-coda, L{sub g}-coda, or P-coda, whichever phase has the best signal-to-noise ratio. The results of this calibration yield source spectra and derived magnitudes that were more stable than any other direct-phase measure to date. Our empirical procedure accounted for all propagation, site, and S-to-coda transfer function effects. The resultant coda-derived moment-rate spectra were used to provide traditional band-limited magnitude (e.g., M{sub L}, m{sub b} etc.) as well as an unbiased, unsaturated magnitude (moment magnitude, M{sub w}) that is tied to a physical measure of earthquake size (i.e., seismic moment). We validated our results by comparing our coda-derived moment estimates with those obtained from long-period waveform modeling. …
Date: July 17, 2003
Creator: Mayeda, K; Eken, T; Hofstetter, A; Turkelli, N; O'Boyle, J; Orgulu, G et al.
Object Type: Article
System: The UNT Digital Library
Nonradiological Environmental Report Maamora Site, Morocco (open access)

Nonradiological Environmental Report Maamora Site, Morocco

Under the Sister Laboratory Arrangement between Lawrence Livermore National Laboratory (LLNL) and the Moroccan National Center for Nuclear Energy Sciences and Techniques (CNESTEN), environmental sampling and analysis were performed to assess the background concentrations of nonradiological constituents in various environmental media at the Maamora Forest CNESTEN Laboratory Site. Samples were collected from surface soil, surface water and groundwater wells, short-lived vegetation (mainly native grass), and long-lived vegetation (cork oak). Samples were collected inside the property fence line, in the buffer zone surrounding the site, and off site at water locations. The soil and vegetation samples were analyzed for metals and pesticides and screened for polychlorinated biphenyls (PCBs); the water samples were analyzed for metals, general minerals, and pesticides and screened for PCBs.
Date: July 17, 2003
Creator: Althouse, P E; Blake, R G; Bandong, B B; Belghit, H & Dehbi, N
Object Type: Report
System: The UNT Digital Library
Complete Oxidation of Methane on Palladium Catalysts. Final Report (open access)

Complete Oxidation of Methane on Palladium Catalysts. Final Report

This is the final report for grant DE-FG02-00ER15026. It summarizes all the accomplishments in these 8 sections: (1) Adaptations on Existing Unit and Construction of New Unit; (2) Turnover Rate and Reaction Orders for the Complete Oxidation of Methane on a Palladium Foil in Excess Dioxygen; (3) Surface area increase on Pd foils after oxidation in excess methane; (4) UV Raman spectroscopic study of hydrogen bonding in gibbsite and bayerite between 93 and 453 K; (5) Coverage of Palladium Catalysts by Oxidized Silicon During Complete Oxidation of Methane; (6) Kinetics of Methane Oxidation under lean conditions over Pd and PdO; (7) An Explanation for the Hysteresis on the Oxidation of Methane; and (8) Structure of Pd(111) after oxidation in O{sub 2}.
Date: July 17, 2003
Creator: Ribeiro, Fabio H.
Object Type: Report
System: The UNT Digital Library
Experiential Education in Groundwater Hydrology: Bridging the Technical-Policy-Populace Gap Final Report (open access)

Experiential Education in Groundwater Hydrology: Bridging the Technical-Policy-Populace Gap Final Report

It is well recognized that half the countries in the world will face significant fresh water shortages in the next 20 years, due largely to growing populations and increased agricultural and industrial demands (Gleick, 1997). These shortages will significantly limit economic growth, decrease the quality of life and human health for billions of people, and could potentially lead to violence and conflict over securing scarce supplies of water. In the Middle East, groundwater represents an important part of water supply in most locations, yet it is the least understood and one of the most fragile components of the entire water resource system. The occurrence of water underground contributes to the illusion of an infinite resource that is immune to anthropogenic activities. Nevertheless, as has been learned in the West, it can become highly impaired through the actions of man--through the disposal of human, animal, or industrial wastes, from excessive irrigation and fertilization practices in agriculture, or from simple overproduction and overexploitation--and can remain so for decades or even centuries. Finding solutions to groundwater resource and quality problems can be complex, time consuming, and costly. As is the case in many places in the world, but especially in the Middle East, …
Date: July 17, 2003
Creator: Tompson, A. F. B.; Maxwell, R. M.; Richardson, J. H.; El Sha'r, W. A.; Rihani, J. F. F.; El-Naser, H. et al.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Improvements in Off-Center Focusing in an X-ray Streak Camera (open access)

Improvements in Off-Center Focusing in an X-ray Streak Camera

Due to the planar construction of present x-ray streak tubes significant off-center defocusing is observed in both static and dynamic images taken with one-dimensional resolution slits. Based on the streak tube geometry curved photocathodes with radii of curvature ranging from 3.5 to 18 inches have been fabricated. We report initial off-center focusing performance data on the evaluation of these ''improved'' photocathodes in an X-ray streak camera and an update on the theoretical simulations to predict the optimum cathode curvature.
Date: July 17, 2003
Creator: McDonald, J. W.; Weber, F.; Holder, J. P. & Bell, P. M.
Object Type: Article
System: The UNT Digital Library
DETECTION OF UNAUTHORIZED CONSTRUCTION EQUIPMENT IN PIPELINE RIGHT-OF-WAYS (open access)

DETECTION OF UNAUTHORIZED CONSTRUCTION EQUIPMENT IN PIPELINE RIGHT-OF-WAYS

Natural gas transmission companies mark the right-of-way areas where pipelines are buried with warning signs to prevent accidental third-party damage. Nevertheless, pipelines are sometimes damaged by third-party construction equipment. A single incident can be devastating, causing death and millions of dollars of property loss. This damage would be prevented if potentially hazardous construction equipment could be detected, identified, and an alert given before the pipeline was damaged. The Gas Technology Institute (GTI) is developing a system to solve this problem by using an optical fiber as a distributed sensor and interrogating the fiber with a custom optical time domain reflectometer. Key issues are the ability to detect encroachment and the ability to discriminate among potentially hazardous and benign encroachments. The work continues on improving the signal-to-noise ratio of the custom OTDR. An avalanche photo-detector, was purchased. It was able to detect weights on the Hergalite fiber as low as one pound. We are also investigating a brighter laser for use with the multimode fibers.
Date: July 17, 2003
Creator: Huebler, James E.
Object Type: Report
System: The UNT Digital Library
New local potential useful for genome annotation and 3D modeling (open access)

New local potential useful for genome annotation and 3D modeling

A new potential energy function representing the conformational preferences of sequentially local regions of a protein backbone is presented. This potential is derived from secondary structure probabilities such as those produced by neural network-based prediction methods. The potential is applied to the problem of remote homolog identification, in combination with a distance dependent inter-residue potential and position-based scoring matrices. This fold recognition jury is implemented in a Java application called JThread. These methods are benchmarked on several test sets, including one released entirely after development and parameterization of JThread. In benchmark tests to identify known folds structurally similar (but not identical) to the native structure of a sequence, JThread performs significantly better than PSI-BLAST, with 10 percent more structures correctly identified as the most likely structural match in a fold library, and 20 percent more structures correctly narrowed down to a set of five possible candidates. JThread also significantly improves the average sequence alignment accuracy, from 53 percent to 62 percent of residues correctly aligned. Reliable fold assignments and alignments are identified, making the method useful for genome annotation. JThread is applied to predicted open reading frames (ORFs) from the genomes of Mycoplasma genitalium and Drosophila melanogaster, identifying 20 new …
Date: July 17, 2003
Creator: Chandonia, John-Marc & Cohen, Fred E.
Object Type: Article
System: The UNT Digital Library