States

Atmospheric Radiation Measurement Program Science Plan (open access)

Atmospheric Radiation Measurement Program Science Plan

The Atmospheric Radiation Measurement (ARM) Program has matured into one of the key programs in the U.S. Climate Change Science Program. The ARM Program has achieved considerable scientific success in a broad range of activities, including site and instrument development, atmospheric radiative transfer, aerosol science, determination of cloud properties, cloud modeling, and cloud parameterization testing and development. The focus of ARM science has naturally shifted during the last few years to an increasing emphasis on modeling and parameterization studies to take advantage of the long time series of data now available. During the next 5 years, the principal focus of the ARM science program will be to: Maintain the data record at the fixed ARM sites for at least the next five years. Improve significantly our understanding of and ability to parameterize the 3-D cloud-radiation problem at scales from the local atmospheric column to the global climate model (GCM) grid square. Continue developing techniques to retrieve the properties of all clouds, with a special focus on ice clouds and mixed-phase clouds. Develop a focused research effort on the indirect aerosol problem that spans observations, physical models, and climate model parameterizations. Implement and evaluate an operational methodology to calculate broad-band heating …
Date: October 31, 2004
Creator: Ackerman, T
Object Type: Report
System: The UNT Digital Library
New Heterogeneous Catalysts for the Selective Reduction of NOx under Lean Conditions. Final Report (open access)

New Heterogeneous Catalysts for the Selective Reduction of NOx under Lean Conditions. Final Report

The original goal of this program was the identification and design of new noble-metal-based catalysts for the selective catalytic reduction of nitric oxide by hydrocarbons under excess oxygen (i.e., ''lean'') conditions (HC-SCR). Work conducted in the first funding cycle of this award (i.e., 1997-2000) was successful in allowing us to develop an understanding of the fundamental surface chemistry taking place during the adsorption and reaction of nitrogen oxides and propylene on the surface of supported noble metal catalysts. Both experimental results collected in our own group as well as molecular simulation results published by Professor Neurock suggested that in order to improve the performance of the Pt catalysts--in terms of the nitrogen selectivity and the temperature window of operation-- it was necessary to introduce a second metal. However, synthesizing such catalysts with the metals of interest (i.e., Pt-Au, Pt-Ru, Pt-Rh, etc.) with some degree of control of the structure and composition of the resulting supported metal particles is in itself a research challenge. Consequently, the bulk of our efforts during the second funding cycle of this award (covered by this report) was shifted to the use of organometallic cluster precursors for the synthesis on novel bimetallic catalysts. During this time …
Date: May 31, 2004
Creator: Amiridis, M. D.
Object Type: Report
System: The UNT Digital Library
ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE/COMBINED CYCLE CT/(CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM) (open access)

ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE/COMBINED CYCLE CT/(CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM)

Power generators are concerned with the maintenance costs associated with the advanced turbines that they are purchasing. Since these machines do not have fully established operation and maintenance (O&M) track records, power generators face financial risk due to uncertain future maintenance costs. This risk is of particular concern, as the electricity industry transitions to a competitive business environment in which unexpected O&M costs cannot be passed through to consumers. These concerns have accelerated the need for intelligent software-based diagnostic systems that can monitor the health of a combustion turbine in real time and provide valuable information on the machine's performance to its owner/operators. EPRI, Impact Technologies, Boyce Engineering, and Progress Energy have teamed to develop a suite of intelligent software tools integrated with a diagnostic monitoring platform that will, in real time, interpret data to assess the ''total health'' of combustion turbines. The Combustion Turbine Health Management System (CTHM) will consist of a series of dynamic link library (DLL) programs residing on a diagnostic monitoring platform that accepts turbine health data from existing monitoring instrumentation. The CTHM system will be a significant improvement over currently available techniques for turbine monitoring and diagnostics. CTHM will interpret sensor and instrument outputs, correlate …
Date: March 31, 2004
Creator: Angello, Leonard
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
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
High-Precision Floating-Point Arithmetic in ScientificComputation (open access)

High-Precision Floating-Point Arithmetic in ScientificComputation

At the present time, IEEE 64-bit floating-point arithmetic is sufficiently accurate for most scientific applications. However, for a rapidly growing body of important scientific computing applications, a higher level of numeric precision is required: some of these applications require roughly twice this level; others require four times; while still others require hundreds or more digits to obtain numerically meaningful results. Such calculations have been facilitated by new high-precision software packages that include high-level language translation modules to minimize the conversion effort. These activities have yielded a number of interesting new scientific results in fields as diverse as quantum theory, climate modeling and experimental mathematics, a few of which are described in this article. Such developments suggest that in the future, the numeric precision used for a scientific computation may be as important to the program design as are the algorithms and data structures.
Date: December 31, 2004
Creator: Bailey, David H.
Object Type: Article
System: The UNT Digital Library
A Pseudo-Random Number Generator Based on Normal Numbers (open access)

A Pseudo-Random Number Generator Based on Normal Numbers

In a recent paper, Richard Crandall and the present author established that each of a certain class of explicitly given real constants, uncountably infinite in number, is b-normal, for an integer that appears in the formula defining the constant. A b-normal constant is one where every string of m digits appears in the base-b expansion of the constant with limiting frequency b{sup -m}. This paper shows how this result can be used to fashion an efficient and effective pseudo-random number generator, which generates successive strings of binary digits from one of the constants in this class. The resulting generator, which tests slightly faster than a conventional linear congruential generator, avoids difficulties with large power-of-two data access strides that may occur when using conventional generators. It is also well suited for parallel processing--each processor can quickly and independently compute its starting value, with the collective sequence generated by all processors being the same as that generated by a single processor.
Date: December 31, 2004
Creator: Bailey, David H.
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
Mitigation bank promotes research on restoring Coastal Plain depression wetlands (South Carolina). (open access)

Mitigation bank promotes research on restoring Coastal Plain depression wetlands (South Carolina).

Barton, Christopher, D., Diane DeSteven and John C. Kilgo. 2004. Mitigation bank promotes research on restoring Coastal Plain depression wetlands (South Carolina). Ecol. Rest. 22(4):291-292. Abstract: Carolina bays and smaller depression wetlands support diverse plant communities and provide critical habitat for semi-aquatic fauna throughout the Coastal Plain region of the southeastern United States. Historically, many depression wetlands were altered or destroyed by surface ditching, drainage, and agricultural or silviculture uses. These important habitats are now at further risk of alteration and loss following a U.S. Supreme Court decision in 2001 restricting federal regulation of isolated wetlands. Thus, there is increased attention towards protecting intact sites and developing methods to restore others. The U.S. Department of Energy's (DOE) 312-mi2 (800-km2) Savannah River Site (SRS) in west-central South Carolina includes about 350 Carolina bays and bay-like wetland depressions, of which about two-thirds were degraded or destroyed prior to federal acquisition of the land. Although some of the altered wetlands have recovered naturally, others still have active active drainage ditches and contain successional forests typical of drained sites. In 1997, DOE established a wetland mitigation bank to compensate for unavoidable wetland impacts on the SRS. This effort provided an opportunity fir a systematic …
Date: December 31, 2004
Creator: Barton, Christopher D.; DeSteven, Diane & Kilgo, John C.
Object Type: Article
System: The UNT Digital Library
DEVELOPING STATE POLICIES SUPPORTIVE OF BIOENERGY DEVELOPMENT (open access)

DEVELOPING STATE POLICIES SUPPORTIVE OF BIOENERGY DEVELOPMENT

Working within the context of the Southern States Biobased Alliance (SSBA) and with officials in each state, the Southern States Energy Board (SSEB) is identifying bioenergy-related policies and programs within each state to determine their impact on the development, deployment or use of bioenergy. In addition, SSEB will determine which policies have impacted industry's efforts to develop, deploy or use biobased technologies or products. As a result, SSEB will work with the Southern States Biobased Alliance to determine how policy changes might address any negative impacts or enhance positive impacts. In addition to analysis of domestic policies and programs, this project will include the development of a U.S.-Brazil Biodiesel Pilot Project. The purpose of this effort is to promote and facilitate the commercialization of biodiesel and bioenergy production and demand in Brazil.
Date: October 31, 2004
Creator: Baskin, Kathryn
Object Type: Report
System: The UNT Digital Library
Southeast Regional Carbon Sequestration Partnership (SECARB) (open access)

Southeast Regional Carbon Sequestration Partnership (SECARB)

Work during the first six months of the project mainly concentrated on contracts execution and collection of data to characterize the region and input of that data into the geographical information system (GIS) system. Data was collected for source characterization, transportation options and terrestrial options. In addition, discussions were held to determine the extent of the geologic information that would be needed for the project. In addition, activities associated with the regulatory, permitting and safety issues were completed. Outreach activities are in the formative stages.
Date: March 31, 2004
Creator: Baskin, Kathryn A.
Object Type: Report
System: The UNT Digital Library
New Jersey Emergency Management and Homeland Security Authorities Summarized (open access)

New Jersey Emergency Management and Homeland Security Authorities Summarized

None
Date: March 31, 2004
Creator: Bea, Keith; Runyon, L. Cheryl & Warnock, Kae M.
Object Type: Report
System: The UNT Digital Library
New Mexico Emergency Management and Homeland Security Authorities Summarized (open access)

New Mexico Emergency Management and Homeland Security Authorities Summarized

None
Date: March 31, 2004
Creator: Bea, Keith; Runyon, L. Cheryl & Warnock, Kae M.
Object Type: Report
System: The UNT Digital Library
Mercury Control With The Advanced Hybrid Particulate Collector (open access)

Mercury Control With The Advanced Hybrid Particulate Collector

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4 - Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore and Associates, Inc., and is now marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears …
Date: March 31, 2004
Creator: Benson, Steven A.; Miller, Stanley J.; Crocker, Charlene R.; Galbreath, Kevin C.; Laumb, Jason D.; Zola, Jill M. et al.
Object Type: Report
System: The UNT Digital Library
Dose Rate Calibration of a Commercial Beta-Particle Irradiator Used in Archeological and Geological Dating (open access)

Dose Rate Calibration of a Commercial Beta-Particle Irradiator Used in Archeological and Geological Dating

None
Date: October 31, 2004
Creator: Bernal, S. M.
Object Type: Report
System: The UNT Digital Library
Dose Rate Calibration of a Commercial Beta-Particle Irradiator Used In Archeological and Geological Dating (open access)

Dose Rate Calibration of a Commercial Beta-Particle Irradiator Used In Archeological and Geological Dating

The 801E Multiple Sample Irradiator, manufactured by Daybreak Nuclear Systems, is capable of exposing up to 30 samples to beta radiation by placing each sample one by one directly beneath a heavily shielded ceramic Sr-90/Y-90 source and opening a specially designed shutter. Daybreak Nuclear Systems does not provide the {sup 90}Sr/{sup 90}Y dose rate to the sample because of variations of up to 20% in the nominal activity of the beta sources (separately manufactured by AEA Technology). Thus it is left to the end user to determine. Here aluminum oxide doped with carbon (Al{sub 2}O{sub 3}:C), in the form of Landauer's Luxel{trademark}, was irradiated to different known doses using a calibrated {sup 90}Sr/{sup 90}Y beta particle irradiator, and the OSL signal monitored after each irradiation to generate a calibration curve. Comparison of the OSL Signal from the unknown 801E Irradiator dose with the calibration curve enabled the dose and therefore dose rate to be determined. The timing accuracy of the 801E Irradiator was also evaluated and found to be +/- 0.5 seconds. The dose rate of the beta source was found to be 0.147 +/- 0.007 Gy/s.
Date: October 31, 2004
Creator: Bernal, S. M.
Object Type: Report
System: The UNT Digital Library
Sampling and Hydrogeology of the Vadose Zone Beneath the 300 Area Process Ponds (open access)

Sampling and Hydrogeology of the Vadose Zone Beneath the 300 Area Process Ponds

Four open pits were dug with a backhoe into the vadose zone beneath the former 300 Area Process Ponds in April 2003. Samples were collected about every 2 feet for physical, chemical, and/or microbiological characterization. This reports presents a stratigraphic and geohydrologic summary of the four excavations.
Date: August 31, 2004
Creator: Bjornstad, Bruce N.
Object Type: Report
System: The UNT Digital Library
NOx Control Options and Integration for US Coal Fired Boilers Quarterly Progress Report: January-March 2004 (open access)

NOx Control Options and Integration for US Coal Fired Boilers Quarterly Progress Report: January-March 2004

This is the fifteenth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project is to develop cost effective analysis tools and techniques for demonstrating and evaluating low NOx control strategies and their possible impact on boiler performance for boilers firing US coals. The Electric Power Research Institute (EPRI) is providing co-funding for this program. At AEP's Gavin Plant, data from the corrosion probes showed that corrosion rate increased as boiler load was increased. During an outage at the plant, the drop in boiler load, sensor temperature and corrosion rate could all be seen clearly. Restarting the boiler saw a resumption of corrosion activity. This behavior is consistent with previous observations made at a 600MWe utility boiler. More data are currently being examined for magnitudes of corrosion rates and changes in boiler operating conditions. Considerable progress was made this quarter in BYU's laboratory study of catalyst deactivation. Surface sulfation appears to partially suppress NO adsorption when the catalyst is not exposed to NH3; NH3 displaces surface-adsorbed NO on SCR catalysts and surface sulfation increases the amount of adsorbed NH3, as confirmed by both spectroscopy and TPD experiments. However, there is no indication of changes in catalyst …
Date: March 31, 2004
Creator: Bockelie, Mike; Davis, Kevin; Linjewile, Temi; Senior, Connie; Eddings, Eric; Whitty, Kevin et al.
Object Type: Report
System: The UNT Digital Library
NOx Control Options and Integration for US Coal Fired Boilers Quarterly Progress Report: October-December 2004 (open access)

NOx Control Options and Integration for US Coal Fired Boilers Quarterly Progress Report: October-December 2004

This is the eighteenth Quarterly Technical Report for DOE Cooperative Agreement No: DEFC26-00NT40753. The goal of the project is to develop cost effective analysis tools and techniques for demonstrating and evaluating low NOx control strategies and their possible impact on boiler performance for boilers firing US coals. The Electric Power Research Institute (EPRI) is providing co-funding for this program. Safety equipment for ammonia for the SCR slipstream reactor at Plant Gadsden was installed. The slipstream reactor was started and operated for about 1400 hours during the last performance period. Laboratory analysis of exposed catalyst and investigations of the sulfation of fresh catalyst continued at BYU. Thicker end-caps for the ECN probes were designed and fabricated to prevent the warpage and failure that occurred at Gavin with the previous design. A refurbished ECN probe was successfully tested at the University of Utah combustion laboratory. Improvements were implemented to the software that controls the flow of cooling air to the ECN probes.
Date: December 31, 2004
Creator: Bockelie, Mike; Davis, Kevin; Senior, Connie; Shino, Darren; Swenson, Dave; Baxter, Larry et al.
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
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
Material Property Estimation for Direct Detection of DNAPL using Integrated Ground-Penetrating Radar Velocity, Imaging and Attribute Analysis (open access)

Material Property Estimation for Direct Detection of DNAPL using Integrated Ground-Penetrating Radar Velocity, Imaging and Attribute Analysis

The focus of this project is direct detection of DNAPLs, specifically chlorinated solvents, via material property estimation from multi-fold surface ground-penetrating radar (GPR) data. We combine state-of-the-art GPR processing methodology with quantitative attribute analysis and material property estimation to determine the location and extent of residual and/or pooled DNAPL in both the vadose and saturated zones. An important byproduct of our research is state-of-the-art imaging which allows us to pinpoint attribute anomalies, characterize stratigraphy, identify fracture zones, and locate buried objects.
Date: December 31, 2004
Creator: Bradford, John H.; Holbrook, W. Stephen & Smithson, Scott B.
Object Type: Report
System: The UNT Digital Library
Corrosion Monitoring System (open access)

Corrosion Monitoring System

The Corrosion Monitoring System (CMS) program developed and demonstrated a continuously on-line system that provides real-time corrosion information. The program focused on detecting pitting corrosion in its early stages. A new invention called the Intelligent Ultrasonic Probe (IUP) was patented on the program. The IUP uses ultrasonic guided waves to detect small defects and a Synthetic Aperture Focusing Technique (SAFT) algorithm to provide an image of the pits. Testing of the CMS demonstrated the capability to detect pits with dimensionality in the sub-millimeter range. The CMS was tested in both the laboratory and in a pulp and paper industrial plant. The system is capable of monitoring the plant from a remote location using the internet.
Date: October 31, 2004
Creator: Braunling, Russ
Object Type: Report
System: The UNT Digital Library
Integrated Field, Laboratory, and Modeling Studies to Determine the Effects of Linked Microbial and Physical Spatial Heterogeneity on Engineered Vadose Zone Bioremediation (open access)

Integrated Field, Laboratory, and Modeling Studies to Determine the Effects of Linked Microbial and Physical Spatial Heterogeneity on Engineered Vadose Zone Bioremediation

Executive Summary - While numerous techniques exist for remediation of contaminant plumes in groundwater or near the soil surface, remediation methods in the deep vadose zone are less established due to complex transport dynamics and sparse microbial populations. There is a lack of knowledge on how physical and hydrologic features of the vadose zone control microbial growth and colonization in response to nutrient delivery during bioremediation. Yet pollution in the vadose zone poses a serious threat to the groundwater resources lying deeper in the sediment. While the contaminants may be slowly degraded by native microbial communities, microbial degradation rates rarely keep pace with the spread of the pollutant. It is crucial to increase indigenous microbial degradation in the vadose zone to combat groundwater contamination...
Date: October 31, 2004
Creator: Brockman, Fred J.; Selker, John S. & Rockhold, Mark L.
Object Type: Report
System: The UNT Digital Library