Advanced Communication and Control of Distributed Energy Resources at Detroit Edison (open access)

Advanced Communication and Control of Distributed Energy Resources at Detroit Edison

The project objective was to create the communication and control system, the process and the economic procedures that will allow owners (e.g., residential, commercial, industrial, manufacturing, etc.) of Distributed Energy Resources (DER) connected in parallel to the electric distribution to have their resources operated in a manner that protects the electric utility distribution network and personnel that may be working on the network. The Distribution Engineering Workstation (DEW) (a power flow and short circuit modeling tool) was modified to calculate the real-time characteristics of the distribution network based on the real-time electric distribution network information and provide DER operating suggestions to the Detroit Edison system operators so that regional electric stability is maintained. Part of the suggestion algorithm takes into account the operational availability of DER’s, which is known by the Energy Aggregator, DTE Energy Technologies. The availability information will be exchanged from DTE Energy Technologies to Detroit Edison. For the calculated suggestions to be used by the Detroit Edison operators, procedures were developed to allow an operator to operate a DER by requesting operation of the DER through DTE Energy Technologies. Prior to issuing control of a DER, the safety of the distribution network and personnel needs to be …
Date: January 31, 2004
Creator: Asgeirsson, Haukur & Seguin, Richard
Object Type: Report
System: The UNT Digital Library
Advanced Cuttings Transport Study Quarterly Report: October-December 2003 (open access)

Advanced Cuttings Transport Study Quarterly Report: October-December 2003

Final design of the mast was completed (Task 5). The mast is consisting of two welded plate girders, set next to each other, and spaced 14-inches apart. Fabrication of the boom will be completed in two parts solely for ease of transportation. The end pivot connection will be made through a single 2-inch diameter x 4 feet-8 inch long 316 SS bar. During installation, hard piping make-ups using Chiksan joints will connect the annular section and 4-inch return line to allow full movement of the mast from horizontal to vertical. Additionally, flexible hoses and piping will be installed to isolate both towers from piping loads and allow recycling operations respectively. Calibration of the prototype Foam Generator Cell has been completed and experiments are now being conducted. We were able to generate up to 95% quality foam. Work is currently underway to attach the Thermo-Haake RS300 viscometer and install a view port with a microscope to measure foam bubble size and bubble size distribution. Foam rheology tests (Task 13) were carried out to evaluate the rheological properties of the proposed foam formulation. After successful completion of the first foam test, two sets of rheological tests were conducted at different foam flow …
Date: January 31, 2004
Creator: Miska, Stefan; Takach, Nicholas & Ashenayi, Kaveh
Object Type: Report
System: The UNT Digital Library
ADVANCED OIL RECOVERY TECHNOLOGIES FOR IMPROVED RECOVERY FROM SLOPE BASIN CLASTIC RESERVOIRS, NASH DRAW BRUSHY CANYON POOL, EDDY COUNTY, NM (open access)

ADVANCED OIL RECOVERY TECHNOLOGIES FOR IMPROVED RECOVERY FROM SLOPE BASIN CLASTIC RESERVOIRS, NASH DRAW BRUSHY CANYON POOL, EDDY COUNTY, NM

The overall objective of this project is to demonstrate that a development program based on advanced reservoir management methods can significantly improve oil recovery at the Nash Draw Pool (NDP). The plan includes developing a control area using standard reservoir management techniques and comparing its performance to an area developed using advanced reservoir management methods. Specific goals are (1) to demonstrate that an advanced development drilling and pressure maintenance program can significantly improve oil recovery compared to existing technology applications and (2) to transfer these advanced methodologies to oil and gas producers in the Permian Basin and elsewhere throughout the U.S. oil and gas industry.
Date: January 31, 2004
Creator: Murphy, Mark B.
Object Type: Report
System: The UNT Digital Library
Coal Integrated Gasification Fuel Cell System Study (open access)

Coal Integrated Gasification Fuel Cell System Study

This study analyzes the performance and economics of power generation systems based on Solid Oxide Fuel Cell (SOFC) technology and fueled by gasified coal. System concepts that integrate a coal gasifier with a SOFC, a gas turbine, and a steam turbine were developed and analyzed for plant sizes in excess of 200 MW. Two alternative integration configurations were selected with projected system efficiency of over 53% on a HHV basis, or about 10 percentage points higher than that of the state-of-the-art Integrated Gasification Combined Cycle (IGCC) systems. The initial cost of both selected configurations was found to be comparable with the IGCC system costs at approximately $1700/kW. An absorption-based CO2 isolation scheme was developed, and its penalty on the system performance and cost was estimated to be less approximately 2.7% and $370/kW. Technology gaps and required engineering development efforts were identified and evaluated.
Date: January 31, 2004
Creator: Balan, Chellappa; Dey, Debashis; Eker, Sukru-Alper; Peter, Max; Sokolov, Pavel & Wotzak, Greg
Object Type: Report
System: The UNT Digital Library
Complete sequences of the highly rearranged molluscan mitochondrial genomes of the scaphopod graptacme eborea and the bivalve mytilus edulis (open access)

Complete sequences of the highly rearranged molluscan mitochondrial genomes of the scaphopod graptacme eborea and the bivalve mytilus edulis

We have determined the complete sequence of the mitochondrial genome of the scaphopod mollusk Graptacme eborea (Conrad, 1846) (14,492 nts) and completed the sequence of the mitochondrial genome of the bivalve mollusk Mytilus edulis Linnaeus, 1758 (16,740 nts). (The name Graptacme eborea is a revision of the species formerly known as Dentalium eboreum.) G. eborea mtDNA contains the 37 genes that are typically found and has the genes divided about evenly between the two strands, but M. edulis contains an extra trnM and is missing atp8, and has all genes on the same strand. Each has a highly rearranged gene order relative to each other and to all other studied mtDNAs. G. eborea mtDNA has almost no strand skew, but the coding strand of M. edulis mtDNA is very rich in G and T. This is reflected in differential codon usage patterns and even in amino acid compositions. G. eborea mtDNA has fewer non-coding nucleotides than any other mtDNA studied to date, with the largest non-coding region being only 24 nt long. Phylogenetic analysis using 2,420 aligned amino acid positions of concatenated proteins weakly supports an association of the scaphopod with gastropods to the exclusion of Bivalvia, Cephalopoda, and Polyplacophora, …
Date: January 31, 2004
Creator: Boore, Jeffrey L.; Medina, Monica & Rosenberg, Lewis A.
Object Type: Article
System: The UNT Digital Library
Composite Cathode for High-Power Density Solid Oxide Fuel Cells (open access)

Composite Cathode for High-Power Density Solid Oxide Fuel Cells

Reduction of solid oxide fuel cell (SOFC) operating temperature will play a key role in reducing the stack cost by allowing the use of low-cost metallic interconnects and new approaches to sealing, while making applications such as transportation more feasible. Reported results for anode-supported SOFCs show that cathode polarization resistance is the primary barrier to achieving high power densities at operating temperatures of 700 C and lower. This project aims to identify and develop composite cathodes that could reduce SOFC operating temperatures below 700 C. This effort focuses on study and use of (La,Sr)(Co,Fe)O{sub 3} (LSCF) based composite cathodes, which have arguably the best potential to substantially improve on the currently-used, (La,Sr)MnO{sub 3}-Yttria-stabilized Zirconia. During this Phase I, it was successfully demonstrated that high performances can be achieved with LSCF/Gadolinium-Doped Ceria composite cathodes on Ni-based anode supported cells operating at 700 C or lower. We studied electrochemical reactions at LSCF/Yttria-stabilized Zirconia (YSZ) interfaces, and observed chemical reactions between LSCF and YSZ. By using ceria electrolytes or YSZ electrolytes with ceria diffusion barrier layers, the chemical reactions between LSCF and electrolytes were prevented under cathode firing conditions necessary for the optimal adhesion of the cathodes. The protection provided by ceria layer …
Date: January 31, 2004
Creator: Kim, Ilwon; Barnett, Scott; Jiang, Yi; Pillai, Manoj; McDonald, Nikkia; Gostovic, Dan et al.
Object Type: Report
System: The UNT Digital Library
Data Standards for the Genomes to Life Program (open access)

Data Standards for the Genomes to Life Program

Existing GTL Projects already have produced volumes of dataand, over the course of the next five years, will produce an estimatedhundreds, or possibly thousands, of terabytes of data from hundreds ofexperiments conducted at dozens of laboratories in National Labs anduniversities across the nation. These data will be the basis forpublications by individual researchers, research groups, andmulti-institutional collaborations, and the basis for future DOEdecisions on funding further research in bioremediation. The short-termand long-term value of the data to project participants, to the DOE, andto the nation depends, however, on being able to access the data and onhow, or whether, the data are archived. The ability to access data is thestarting point for data analysis and interpretation, data integration,data mining, and development of data-driven models. Limited orinefficient data access means that less data are analyzed in acost-effective and timely manner. Data production in the GTL Program willlikely outstrip, or may have already outstripped, the ability to analyzethe data. Being able to access data depends on two key factors: datastandards and implementation of the data standards. For the purpose ofthis proposal, a data standard is defined as a standard, documented wayin which data and information about the data are describe. The attributesof the …
Date: January 31, 2004
Creator: Arkin, Adam; Ambrosiano, John; Babnigg, Gyorgy; Frank, Ed; Geist,Al; Giometti, Carol et al.
Object Type: Report
System: The UNT Digital Library
Enhancement of Terrestrial Carbon Sinks through the Reclamation of Abandoned Mined Lands (open access)

Enhancement of Terrestrial Carbon Sinks through the Reclamation of Abandoned Mined Lands

None
Date: January 31, 2004
Creator: Kronrad, Gary
Object Type: Report
System: The UNT Digital Library
Environmentally Benign Mitigation of Microbiologically Influenced Corrosion (MIC) (open access)

Environmentally Benign Mitigation of Microbiologically Influenced Corrosion (MIC)

The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. The technical approach for this quarter included the fractionation of extracts prepared from several varieties of pepper plants, and using several solvents, by high performance liquid chromatography (HPLC). A preliminary determination of antimicrobial activities of the new extracts and fractions using a growth inhibition assay, and evaluation of the extracts ability to inhibit biofilm formation was also performed. The analysis of multiple extracts of pepper plants and fractions of extracts of pepper plants obtained by HPLC illustrated that these extracts and fractions are extremely complex mixtures of chemicals. Gas chromatography-mass spectrometry was used to identify the chemical constituents of these extracts and fractions to the greatest degree possible. Analysis of the chemical composition of various extracts of pepper plants has illustrated the complexity of the chemical mixtures present, and while additional work will be performed …
Date: January 31, 2004
Creator: Kilbane, John J., II & Bogan, William
Object Type: Report
System: The UNT Digital Library
Harmonic resolution as a holographic quantum number (open access)

Harmonic resolution as a holographic quantum number

The Bekenstein bound takes the holographic principle into the realm of flat space, promising new insights on the relation of non-gravitational physics to quantum gravity. This makes it important to obtain a precise formulation of the bound. Conventionally, one specifies two macroscopic quantities, mass and spatial width, which cannot be simultaneously diagonalized. Thus, the counting of compatible states is not sharply defined. The resolution of this and other formal difficulties leads naturally to a definition in terms of discretized light-cone quantization. In this form, the area difference specified in the covariant bound converts to a single quantum number, the harmonic resolution K. The Bekenstein bound then states that the Fock space sector with K units of longitudinal momentum contains no more than exp(2 pi^2 K) independent discrete states. This conjecture can be tested unambiguously for a given Lagrangian, and it appears to hold true for realistic field theories, including models arising from string compactifications. For large K, it makes contact with more conventional but less well-defined formulations.
Date: January 31, 2004
Creator: Bousso, Raphael
Object Type: Article
System: The UNT Digital Library
Optimizing Techology to Reduce Mercury and Acid Gas Emissions from Electric Power Plants (open access)

Optimizing Techology to Reduce Mercury and Acid Gas Emissions from Electric Power Plants

More than 56,000 coal quality data records from five public data sets have been selected for use in this project. These data will be used to create maps showing where coals with low mercury and acid-gas emissions might be found for power plants classified by air-pollution controls. Average coal quality values, calculated for 51,156 commercial coals by U.S. county-of-origin, are listed in the appendix. Coal moisture values are calculated for commercially shipped coal from 163 U.S. counties, where the raw assay data (including mercury and chlorine values) are reported on a dry basis. The calculated moisture values are verified by comparison with observed moisture values in commercial coal. Moisture in commercial U.S. coal shows provincial variation. For example, high volatile C bituminous rank coal from the Interior province has 3% to 4% more moisture than equivalent Rocky Mountain province coal. Mott-Spooner difference values are calculated for 4,957 data records for coals collected from coal mines and exploration drill holes. About 90% of the records have Mott-Spooner difference values within {+-}250 Btu/lb.
Date: January 31, 2004
Creator: Quick, Jeffrey C.; Tabet, David E.; Wakefield, Sharon & Bon, Roger L.
Object Type: Report
System: The UNT Digital Library
PILOT DEMONSTRATION OF TECHNOLOGY FOR THE PRODUCTION OF HIGH VALUE MATERIALSFROM THE ULTRA-FINE (PM2.5)FRACTION OF COAL COMBUSTION ASH (open access)

PILOT DEMONSTRATION OF TECHNOLOGY FOR THE PRODUCTION OF HIGH VALUE MATERIALSFROM THE ULTRA-FINE (PM2.5)FRACTION OF COAL COMBUSTION ASH

Dry fly ash samples were collected from 6 of the7 largest power plants operated by Louisville Gas and Electric Company (LG&E). Samples were taken from individual ESP hoppers in a continuous flow through stages of particulate collection. A total of 41 samples were taken from 16 operating units. The samples were thoroughly characterized for pertinent physical and chemical composition. The fly ash samples contained 10 to 50% -10{micro}m material, with higher concentrations of finer particles located in the latter stages of particulate collection. Flotation evaluation was conducted on a continuous flow though a single unit at each power station to assess the viability of using froth flotation to reduce the LOI in the fly ash to very low levels (i.e. 0.5% LOI) in order to enable eventual use as fillers. Ash from all of the units tested responded favorably with the exception of the ash from Henderson Station, which is attributed to a significant proportion of un-combusted or partially-combusted petroleum coke in the ash at this station, Bulk samples of dry ash and pond ash were also collected from Mill Creek, Trimble County, E.W. Brown and Coleman power plants and evaluated for carbon removal by froth flotation. Release analyses showed …
Date: January 31, 2004
Creator: Robl, T.L. & Groppo, J.G.
Object Type: Report
System: The UNT Digital Library
The Shortwave (SW) Clear-Sky Detection and Fitting Algorithm: Algorithm Operational Details and Explanations (open access)

The Shortwave (SW) Clear-Sky Detection and Fitting Algorithm: Algorithm Operational Details and Explanations

This document describes some specifics of the algorithm for detecting clear skies and fitting clear-sky shortwave (SW) functions described in Long and Ackerman (2000). This algorithm forms the basis of the ARM SW FLUX ANAL 1Long VAP. In the Atmospheric Radiation Measurement (ARM) case, the value added procedures (VAP) can be described as having three parts: a “front end,” a “black box,” and a “back end.” The “front end” handles the file management of the processing, what range of data files to process in the run, which configuration file to use for each site, extracting the data from the ARM NetCDF files into an ASCII format for the code to process, etc. The “back end” produces ARM-format NetCDF files of the output and other file management. The “black box” is the processing code(s), and is what is discussed in this document. Details on the “front” and “back” ends of the ARM VAP are presented elsewhere.
Date: January 31, 2004
Creator: Long, CN & Gaustad, KL
Object Type: Report
System: The UNT Digital Library
Surfactant Spray: A Novel Technology to Improve Flotation Deinking Performance: Final Report (open access)

Surfactant Spray: A Novel Technology to Improve Flotation Deinking Performance: Final Report

Based on the fundamental understanding of ink removal and fiber loss mechanism in flotation deinking process, we developed this innovative technology using surfactant spray to improve the ink removal efficiency, reduce the water and fiber loss, reduce the chemical consumption and carry over in the flotation deinking. The innovative flotation deinking process uses a spray to deliver the frothing agent during flotation deinking to control several key process variables. The spray can control the foam stability and structure and modify the fluid dynamics to reduce the fibers entrapped in the froth layer. The froth formed at the top part of the flotation column will act as a physical filter to prevent the penetration of frothing agent into the pulp suspension to eliminate fiber contamination and unfavorable deinking surface chemistry modification due to surfactant adsorption on the fiber surface. Because of the filter effect, frothing agents will be better utilized. Under the sponsorships of the US Dept. of Energy (DOE) and the member companies of the Institute of Paper Science and Technology, we studied the chem-mechanical mechanism of surfactant spray for flotation deinking using different furnishes, chemicals, and flotation devices in the past four years. In the final year of the …
Date: January 31, 2004
Creator: Deng, Yulin & Zhu, Junyong
Object Type: Report
System: The UNT Digital Library
Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants (open access)

Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

The objective of this project is to develop an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. Currently, this project is focusing on four basic categories of dense membranes: (1) mixed conducting ceramic/ceramic composites, (2) mixed conducting ceramic/metal (cermet) composites, (3) cermets with hydrogen permeable metals, and (4) layered composites with hydrogen permeable alloys. The primary technical challenge in achieving the goals of this project will be to optimize membrane composition to enable practical hydrogen separation rates and chemical stability. Other key aspects of this developing technology include catalysis, ceramic processing methods, and separation unit design operating under high pressure. To achieve these technical goals, Eltron Research Inc. has organized a consortium consisting of CoorsTek, Sued Chemie, Inc. (SCI), Argonne National Laboratory (ANL), and NORAM. Hydrogen permeation rates in excess of 50 mL {center_dot} min{sup -1} {center_dot} cm{sup 2} at {approx}440 C were routinely achieved under less than optimal experimental conditions using a range of membrane compositions. Factors that limit the maximum permeation attainable were determined to be mass transport resistance of H{sub 2} to and from the membrane surface, as well as surface contamination. Mass transport resistance …
Date: January 30, 2004
Creator: Roark, Shane E.; Sammells, Anthony F.; Mackay, Richard; Morrison, Scott R.; Rolfe, Sara L.; Balachandran, U. et al.
Object Type: Report
System: The UNT Digital Library
An Analysis of Price Determination and Markups in the Air-Conditioning and Heating Equipment Industry (open access)

An Analysis of Price Determination and Markups in the Air-Conditioning and Heating Equipment Industry

In this report we calculate the change in final consumer prices due to minimum efficiency standards, focusing on a standard economic model of the air-conditioning and heating equipment (ACHE) wholesale industry. The model examines the relationship between the marginal cost to distribute and sell equipment and the final consumer price in this industry. The model predicts that the impact of a standard on the final consumer price is conditioned by its impact on marginal distribution costs. For example, if a standard raises the marginal cost to distribute and sell equipment a small amount, the model predicts that the standard will raise the final consumer price a small amount as well. Statistical analysis suggest that standards do not increase the amount of labor needed to distribute equipment the same employees needed to sell lower efficiency equipment can sell high efficiency equipment. Labor is a large component of the total marginal cost to distribute and sell air-conditioning and heating equipment. We infer from this that standards have a relatively small impact on ACHE marginal distribution and sale costs. Thus, our model predicts that a standard will have a relatively small impact on final ACHE consumer prices. Our statistical analysis of U.S. Census …
Date: January 30, 2004
Creator: Dale, Larry; Millstein, Dev; Coughlin, Katie; Van Buskirk, Robert; Rosenquist, Gregory; Lekov, Alex et al.
Object Type: Report
System: The UNT Digital Library
Calcium Carbonate Production by Coccolithaphorid Algae in Long Term, Carbon Dioxide Sequestration (open access)

Calcium Carbonate Production by Coccolithaphorid Algae in Long Term, Carbon Dioxide Sequestration

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried …
Date: January 30, 2004
Creator: Fabry, V. J.
Object Type: Report
System: The UNT Digital Library
Competitive sorption of cadmium and lead in acid soils of central Spain (open access)

Competitive sorption of cadmium and lead in acid soils of central Spain

The bioavailability and ultimate fate of heavy metals in the environment are controlled by chemical sorption. To assess competitive sorption of Pb and Cd, batch equilibrium experiments (generating sorption isotherms) and kinetics sorption studies were performed using single and binary metal solutions in surface samples of four soils from central Spain. For comparisons between soils, as well as, single and binary metal solutions, soil chemical processes were characterized using the Langmuir equation, ionic strength, and an empirical power function for kinetic sorption. In addition, soil pH and clay mineralogy were used to explain observed sorption processes. Sorption isotherms were well described by the Langmuir equation and the sorption kinetics were well described by an empirical power function within the reaction times in this study. Soils with higher pH and clay content (characterized by having smectite) had the greatest sorption capacity as estimated by the maximum sorption parameter (Q) of the Langmuir equation. All soils exhibited greater sorption capacity for Pb than Cd and the presence of both metals reduced the tendency for either to be sorbed although Cd sorption was affected to a greater extent than that of Pb. The Langmuir binding strength parameter (k) was always greater for Pb …
Date: January 30, 2004
Creator: Serrano, S.; Garrido, F.; Campbell, C. G. & Garcia-Gonzolez, Maria Teresa
Object Type: Article
System: The UNT Digital Library
THE DEVELOPMENT OF COAL-BASED TECHNOLOGIES FOR DEPARTMENT OF DEFENSE FACILITIES (open access)

THE DEVELOPMENT OF COAL-BASED TECHNOLOGIES FOR DEPARTMENT OF DEFENSE FACILITIES

The third phase of a three-phase project investigating the development of coal-based technologies for US Department of Defense (DOD) facilities was completed. The objectives of the project were to: decrease DOD's dependence on foreign oil and increase its use of coal; promote public and private sector deployment of technologies for utilizing coal-based fuels in oil-designed combustion equipment; and provide a continuing environment for research and development of coal-based fuel technologies for small-scale applications at a time when market conditions in the US are not favorable for the introduction of coal-fired equipment in the commercial and industrial capacity ranges. The Phase III activities were focused on evaluating deeply-cleaned coals as fuels for industrial boilers and investigating emissions control strategies for providing ultra-low emissions when firing coal-based fuels. This was addressed by performing coal beneficiation and preparation studies, and bench- to demonstration-scale emissions reduction studies. In addition, economic studies were conducted focused on determining cost and market penetration, selection of incentives, and regional economic impacts of coal-based technologies.
Date: January 30, 2004
Creator: Miller, Bruce G.; Miller, Sharon Falcone; Pisupati, Sarma V.; Song, Chunshan; Wasco, Ronald S.; Wincek, Ronald T. et al.
Object Type: Report
System: The UNT Digital Library
Direct evidence of the fermi-energy-dependent formation of Mn interstitials in modulation doped Ga1-yAlyAs/Ga1-xMnxAs/Ga1-yAlyAs heterostructures (open access)

Direct evidence of the fermi-energy-dependent formation of Mn interstitials in modulation doped Ga1-yAlyAs/Ga1-xMnxAs/Ga1-yAlyAs heterostructures

Using ion channeling techniques, we investigate the lattice locations of Mn in Ga{sub 1-x}Mn{sub x}As quantum wells between Be-doped Ga{sub 1-y}Al{sub y}As barriers. The earlier results showed that the Curie temperature T{sub C} depends on the growth sequence of the epitaxial layers. A lower T{sub C} was found in heterostructures in which the Ga{sub 1-x}Mn{sub x}As layer is grown after the modulation-doped barrier. Here we provide direct evidence that this reduction in T{sub C} is directly correlated with an increased formation of magnetically inactive Mn interstitials. The formation of interstitials is induced by a shift of the Fermi energy as a result of the transfer of holes from the barrier to the quantum well during the growth.
Date: January 30, 2004
Creator: Yu, K.M.; Walukiewicz, W.; Wojtowicz, T.; Lim, W.L.; Liu, X.; Dobrowolska, M. et al.
Object Type: Article
System: The UNT Digital Library
DropTests of 325 Pound 6M Packages (open access)

DropTests of 325 Pound 6M Packages

There are many factors which affect the performance of a drum closure during drop tests. Important test conditions are: weight of package, height of drop, and angle of impact. Structural characteristics of the package determine its ability to withstand the test conditions imposed. These characteristics include: package diameter, shell material and thickness, strength of internal fill material (e.g., fiberboard), and configuration of closure (clamp-ring, bolted flange, etc.). For the clamp-ring closure configuration a study of published drop test results has shown that packages having a weight ratio of less than 50 per cent were typically able to retain their lids in hypothetical accident condition, 30-ft drop tests. Those having weight ratios greater than 50 per cent typically failed. Prior testing over the integrity of the clamp-ring closure, consistently demonstrated that the clamp-ring is unable to retain the drum lid in thirty foot drop tests of packages containing the maximum allowed weight (640 lb), which confirms the previous studies. To determine if the clamp-ring closure is adequate for packages with lower weight contents, a series of tests were performed on packages weighing around 325 lb (i.e., a typical shipping weight for DOE packages) at a range of impact angles as detailed …
Date: January 30, 2004
Creator: Gelder, L. A.
Object Type: Report
System: The UNT Digital Library
ENHANCED PRACTICAL PHOTOSYNTHETIC CO2 MITIGATION (open access)

ENHANCED PRACTICAL PHOTOSYNTHETIC CO2 MITIGATION

This quarterly report documents significant achievements in the Enhanced Practical Photosynthetic CO{sub 2} Mitigation project during the period from 10/2/2003 through 1/1/2004. As indicated in the list of accomplishments below we have seen very encouraging results from the model scale tests in terms of organism growth rates and we have begun the final tests necessary to meet our project goals. Specific results and accomplishments for the fourth quarter of 2003 include: (1) Bioreactor support systems and test facilities--(A) The solar collector is working well and has survived the winter weather. (B) The improved high-flow CRF-2 test system has been used successfully to run several long-term growth tests with periodic harvesting events. The high flow harvesting system performed well. The mass measurement results after a 4-week test show 275% growth over the initial mass loading. This figure would have been higher had there been no leakage and handling losses. Carbon dating of biomass from this test is planned for carbon uptake estimation. The next test will include direct measurement of carbon uptake in addition to organism mass measurements. (C) Qualitative organism growth testing has begun in the pilot scale bioreactor. Some issues with uniformity of organism loading, fluid leakage and evaporation …
Date: January 30, 2004
Creator: Kremer, Gregory; Bayless, David J.; Vis, Morgan; Prudich, Michael; Cooksey, Keith & Muhs, Jeff
Object Type: Report
System: The UNT Digital Library
Field Demonstration of a Membrane Process to Separate Nitrogen From Natural Gas Progress Report (open access)

Field Demonstration of a Membrane Process to Separate Nitrogen From Natural Gas Progress Report

The original proposal described the construction and operation of a 1 MMscfd treatment system to be operated at a Butcher Energy gas field in Ohio. The gas produced at this field contained 17% nitrogen. During pre-commissioning of the project, a series of well tests showed that the amount of gas in the field was significantly smaller than expected and that the nitrogen content of the wells was very high (25 to 30%). After evaluating the revised cost of the project, Butcher Energy decided that the plant would not be economical and withdrew from the project. Since that time, Membrane Technology and Research, Inc. (MTR) has signed a marketing and sales partnership with ABB Lummus Global. MTR will be working with the company's Randall Gas Technology group, a supplier of equipment and processing technology to the natural gas industry. Randall's engineering group has found a new site for the project at a North Texas Exploration (NTE) gas processing plant. The plant produces about 1 MMscfd of gas containing 24% nitrogen. The membrane unit will bring this gas to 4% nitrogen for delivery to the pipeline. The membrane skid is being built by ABB. NTE has ordered the required compressor and MTR …
Date: January 30, 2004
Creator: Lokhandwala, Kaaeid
Object Type: Report
System: The UNT Digital Library
FY01 Phytoremediation of Chlorinated Ethenes in Southern Sector Seepline Sediments of SRS (open access)

FY01 Phytoremediation of Chlorinated Ethenes in Southern Sector Seepline Sediments of SRS

This treatability study is now in the second year of deployment for the Southern Sector Phytoremediation Project. Phytoremediation is the use of vegetation and associated media to treat contaminated soils, sediments, and groundwater. Phytoremediation is a rapidly developing technology that promises effective and safe cleanup of certain hazardous wastes. This ongoing work addresses the fate of volatile organic contaminants (VOCs) in an experiment that simulates a vegetated seepline supplied with trichloroethylene- (TCE-) and perchloroethylene- (PCE-) contaminated groundwater. The primary objective is to determine how the trees and sediments uptake groundwater TCE and PCE, biodegrade it, and/or transform it. The experimental focus of this project is the biological removal of VOCs from seepline groundwater and sediments.
Date: January 30, 2004
Creator: Brigmon, R.L.
Object Type: Report
System: The UNT Digital Library