Simulations of divertor particle and heat loads in ohmic and L-mode plasmas in DIII-D, AUG, and JET using UEDGE (open access)

Simulations of divertor particle and heat loads in ohmic and L-mode plasmas in DIII-D, AUG, and JET using UEDGE

None
Date: May 17, 2010
Creator: Groth, M.; Porter, G. D.; Rensink, M. E.; Rognlien, T. D.; Wiesen, S.; Wischmeier, M. et al.
Object Type: Article
System: The UNT Digital Library
Optimization of azimuthal uniformity of thermal conductance between AI TMP and Si cooling arms (open access)

Optimization of azimuthal uniformity of thermal conductance between AI TMP and Si cooling arms

None
Date: February 17, 2010
Creator: Bhandarkar, S D; Mapoles, E A; Kroll, J J; Taylor, J S; Haid, B; Sater, J D et al.
Object Type: Article
System: The UNT Digital Library
Tungsten transport in the NSTX tokamak (open access)

Tungsten transport in the NSTX tokamak

None
Date: May 17, 2010
Creator: Clementson, J; Beiersdorfer, P; Roquemore, A L; Skinner, C H; Mansfield, D K; Hartzfeld, K et al.
Object Type: Article
System: The UNT Digital Library
Deployment Effects of Marine Renewable Energy Technologies: Wave Energy Scenarios (open access)

Deployment Effects of Marine Renewable Energy Technologies: Wave Energy Scenarios

Given proper care in siting, design, deployment, operation and maintenance, wave energy conversion could become one of the more environmentally benign sources of electricity generation. In order to accelerate the adoption of these emerging hydrokinetic and marine energy technologies, navigational and environmental concerns must be identified and addressed. All developing hydrokinetic projects involve a wide variety of stakeholders. One of the key issues that site developers face as they engage with this range of stakeholders is that, due to a lack of technical certainty, many of the possible conflicts (e.g., shipping and fishing) and environmental issues are not well-understood,. In September 2008, re vision consulting, LLC was selected by the Department of Energy (DoE) to apply a scenario-based assessment to the emerging hydrokinetic technology sector in order to evaluate the potential impact of these technologies on the marine environment and navigation constraints. The project’s scope of work includes the establishment of baseline scenarios for wave and tidal power conversion at potential future deployment sites. The scenarios capture variations in technical approaches and deployment scales to properly identify and characterize environmental effects and navigational effects. The goal of the project is to provide all stakeholders with an improved understanding of the …
Date: June 17, 2010
Creator: Previsic, Mirko
Object Type: Report
System: The UNT Digital Library
Potential nanotechnology applications for reducing freshwater consumption at coal fired power plants : an early view. (open access)

Potential nanotechnology applications for reducing freshwater consumption at coal fired power plants : an early view.

This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements the overall research effort of the Existing Plants Research Program by evaluating water issues that could impact power plants. A growing challenge to the economic production of electricity from coal-fired power plants is the demand for freshwater, particularly in light of the projected trends for increasing demands and decreasing supplies of freshwater. Nanotechnology uses the unique chemical, physical, and biological properties that are associated with materials at the nanoscale to create and use materials, devices, and systems with new functions and properties. It is possible that nanotechnology may open the door to a variety of potentially interesting ways to reduce freshwater consumption at power plants. This report provides an overview of how applications of nanotechnology could potentially help reduce freshwater use at coal-fired power plants. It was developed by (1) identifying areas within a coal-fired power plant's operations where freshwater use occurs and could possibly be reduced, (2) conducting a literature review to identify potential applications of nanotechnology for facilitating such reductions, and …
Date: September 17, 2010
Creator: Elcock, D. (Environmental Science Division)
Object Type: Report
System: The UNT Digital Library
Using a two-step matrix solution to reduce the run time in KULL's magnetic diffusion package (open access)

Using a two-step matrix solution to reduce the run time in KULL's magnetic diffusion package

Recently a Resistive Magnetohydrodynamics (MHD) package has been added to the KULL code. In order to be compatible with the underlying hydrodynamics algorithm, a new sub-zonal magnetics discretization was developed that supports arbitrary polygonal and polyhedral zones. This flexibility comes at the cost of many more unknowns per zone - approximately ten times more for a hexahedral mesh. We can eliminate some (or all, depending on the dimensionality) of the extra unknowns from the global matrix during assembly by using a Schur complement approach. This trades expensive global work for cache-friendly local work, while still allowing solution for the full system. Significant improvements in the solution time are observed for several test problems.
Date: December 17, 2010
Creator: Brunner, T A & Kolev, T V
Object Type: Article
System: The UNT Digital Library
The use of a high-order MEMS deformable mirror in the Gemini Planet Imager (open access)

The use of a high-order MEMS deformable mirror in the Gemini Planet Imager

We briefly review the development history of the Gemini Planet Imager's 4K Boston Micromachines MEMS deformable mirror. We discuss essential calibration steps and algorithms to control the MEMS with nanometer precision, including voltage-phase calibration and influence function characterization. We discuss the integration of the MEMS into GPI's Adaptive Optics system at Lawrence Livermore and present experimental results of 1.5 kHz closed-loop control. We detail mitigation strategies in the coronagraph to reduce the impact of abnormal actuators on final image contrast.
Date: December 17, 2010
Creator: Poyneer, L. A.; Bauman, B.; Cornelissen, S.; Jones, S.; Macintosh, B.; Palmer, D. et al.
Object Type: Article
System: The UNT Digital Library
Deployment Effects of Marin Renewable Energy Technologies (open access)

Deployment Effects of Marin Renewable Energy Technologies

Given proper care in siting, design, deployment, operation and maintenance, marine and hydrokinetic technologies could become one of the more environmentally benign sources of electricity generation. In order to accelerate the adoption of these emerging hydrokinetic and marine energy technologies, navigational and environmental concerns must be identified and addressed. All developing hydrokinetic projects involve a wide variety of stakeholders. One of the key issues that site developers face as they engage with this range of stakeholders is that many of the possible conflicts (e.g., shipping and fishing) and environmental issues are not well-understood, due to a lack of technical certainty. In September 2008, re vision consulting, LLC was selected by the Department of Energy (DoE) to apply a scenario-based approach to the emerging wave and tidal technology sectors in order to evaluate the impact of these technologies on the marine environment and potentially conflicting uses. The project’s scope of work includes the establishment of baseline scenarios for wave and tidal power conversion at potential future deployment sites. The scenarios will capture variations in technical approaches and deployment scales to properly identify and characterize environmental impacts and navigational effects. The goal of the project is to provide all stakeholders with an …
Date: June 17, 2010
Creator: Polagye, Brian & Previsic, Mirko
Object Type: Report
System: The UNT Digital Library

Alternations of Structure and Functional Activity of Below Ground Microbial Communities at Elevated Atmospheric Carbon Dioxide

The global atmospheric concentration of CO2 has increased by more than 30percent since the industrial revolution. Although the stimulating effects of elevated CO2 (eCO2) on plant growth and primary productivity have been well studied, its influences on belowground microbial communities are poorly understood and controversial. In this study, we showed a significant change in the structure and functional potential of soil microbial communities at eCO2 in a grassland ecosystem, the BioCON (Biodiversity, CO2 and Nitrogen) experimental site (http://www.biocon.umn.edu/) using a comprehensive functional gene array, GeoChip 3.0, which contains about 28,0000 probes and covers approximately 57,000 gene variants from 292 functional gene families involved in carbon, nitrogen, phosphorus and sulfur cycles as well as other functional processes. GeoChip data indicated that the functional structure of microbial communities was markedly different between ambient CO2 (aCO2) and eCO2 by detrended correspondence analysis (DCA) of all 5001 detected functional gene probes although no significant differences were detected in the overall microbial diversity. A further analysis of 1503 detected functional genes involved in C, N, P, and S cycles showed that a considerable portion (39percent) of them were only detected under either aCO2 (14percent) or eCO2 (25percent), indicating that the functional characteristics of the microbial …
Date: May 17, 2010
Creator: He, Zhili; Xu, Meiying; Deng, Ye; Kang, Sanghoon; Wu, Liyou; Van Nostrand, Joy D. et al.
Object Type: Poster
System: The UNT Digital Library
ESTABLISHING FINAL END STATE FOR A RETIRED NUCLEAR WEAPONS PRODUCTION REACTOR; COLLABORATION BETWEEN STAKEHOLDERS, REGULATORS, AND THE FEDERAL GOVERNMENT - 11052 (open access)

ESTABLISHING FINAL END STATE FOR A RETIRED NUCLEAR WEAPONS PRODUCTION REACTOR; COLLABORATION BETWEEN STAKEHOLDERS, REGULATORS, AND THE FEDERAL GOVERNMENT - 11052

The Savannah River Site (SRS) is a 310-square-mile United States Department of Energy nuclear facility located along the Savannah River (SRS) near Aiken, South Carolina. Nuclear weapons material production began in the early 1950s, utilizing five production reactors. In the early 1990s all SRS production reactor operations were terminated. The first reactor closure end state declaration was recently institutionalized in a Comprehensive Environmental Response and Compensation and Liability Act (CERCLA) Early Action Record of Decision. The decision for the final closure of the 318,000 square foot 105-P Reactor was determined to be in situ decommissioning (ISD). ISD is an acceptable and cost effective alternative to off-site disposal for the reactor building, which will allow for consolidation of remedial action wastes generated from other cleanup activities within the P Area. ISD is considered protective by the regulators, U. S. Environmental Protection Agency (US EPA) and the South Carolina Department of Health and Environmental Control (SCDHEC), public and stakeholders as waste materials are stabilized/immobilized, and radioactivity is allowed to naturally decay, thus preventing future exposure to the environment. Stakeholder buy-in was critical in the upfront planning in order to achieve this monumental final decision. Numerous public meetings and workshops were held in …
Date: November 17, 2010
Creator: Bergren, C.; Flora, M. & Belencan, H.
Object Type: Article
System: The UNT Digital Library

HuMiChip: Development of a Functional Gene Array for the Study of Human Microbiomes

Microbiomes play very important roles in terms of nutrition, health and disease by interacting with their hosts. Based on sequence data currently available in public domains, we have developed a functional gene array to monitor both organismal and functional gene profiles of normal microbiota in human and mouse hosts, and such an array is called human and mouse microbiota array, HMM-Chip. First, seed sequences were identified from KEGG databases, and used to construct a seed database (seedDB) containing 136 gene families in 19 metabolic pathways closely related to human and mouse microbiomes. Second, a mother database (motherDB) was constructed with 81 genomes of bacterial strains with 54 from gut and 27 from oral environments, and 16 metagenomes, and used for selection of genes and probe design. Gene prediction was performed by Glimmer3 for bacterial genomes, and by the Metagene program for metagenomes. In total, 228,240 and 801,599 genes were identified for bacterial genomes and metagenomes, respectively. Then the motherDB was searched against the seedDB using the HMMer program, and gene sequences in the motherDB that were highly homologous with seed sequences in the seedDB were used for probe design by the CommOligo software. Different degrees of specific probes, including gene-specific, …
Date: May 17, 2010
Creator: Tu, Q.; Deng, Ye; Lin, Lu; Hemme, Chris L.; He, Zhili & Zhou, Jizhong
Object Type: Poster
System: The UNT Digital Library
Review of Quantitative Software Reliability Methods (open access)

Review of Quantitative Software Reliability Methods

The current U.S. Nuclear Regulatory Commission (NRC) licensing process for digital systems rests on deterministic engineering criteria. In its 1995 probabilistic risk assessment (PRA) policy statement, the Commission encouraged the use of PRA technology in all regulatory matters to the extent supported by the state-of-the-art in PRA methods and data. Although many activities have been completed in the area of risk-informed regulation, the risk-informed analysis process for digital systems has not yet been satisfactorily developed. Since digital instrumentation and control (I&C) systems are expected to play an increasingly important role in nuclear power plant (NPP) safety, the NRC established a digital system research plan that defines a coherent set of research programs to support its regulatory needs. One of the research programs included in the NRC's digital system research plan addresses risk assessment methods and data for digital systems. Digital I&C systems have some unique characteristics, such as using software, and may have different failure causes and/or modes than analog I&C systems; hence, their incorporation into NPP PRAs entails special challenges. The objective of the NRC's digital system risk research is to identify and develop methods, analytical tools, and regulatory guidance for (1) including models of digital systems into NPP …
Date: September 17, 2010
Creator: Chu, T. L.; Yue, M.; Martinez-Guridi, M. & Lehner, J.
Object Type: Report
System: The UNT Digital Library
Precision Engineering within the National Ignition Campaign (open access)

Precision Engineering within the National Ignition Campaign

In this very brief talk, we'll discuss how precision engineering impacts 4 key areas of NIF: (1) Diamond turning of KDP crystals; (2) Mitigation of laser damage on optics; (3) Alignment of lasers, targets, diagnostics; (4) Target fabrication.
Date: February 17, 2010
Creator: Taylor, J S; Carlisle, K; Klingmann, J L; Geraghty, P; Saito, T T & Montesanti, R C
Object Type: Article
System: The UNT Digital Library
Development of Crystal-Tolerant High-Level Waste Glasses (open access)

Development of Crystal-Tolerant High-Level Waste Glasses

Twenty five glasses were formulated. They were batched from HLW AZ-101 simulant or raw chemicals and melted and tested with a series of tests to elucidate the effect of spinel-forming components (Ni, Fe, Cr, Mn, and Zn), Al, and noble metals (Rh2O3 and RuO2) on the accumulation rate of spinel crystals in the glass discharge riser of the high-level waste (HLW) melter. In addition, the processing properties of glasses, such as the viscosity and TL, were measured as a function of temperature and composition. Furthermore, the settling of spinel crystals in transparent low-viscosity fluids was studied at room temperature to access the shape factor and hindered settling coefficient of spinel crystals in the Stokes equation. The experimental results suggest that Ni is the most troublesome component of all the studied spinel-forming components producing settling layers of up to 10.5 mm in just 20 days in Ni-rich glasses if noble metals or a higher concentration of Fe was not introduced in the glass. The layer of this thickness can potentially plug the bottom of the riser, preventing glass from being discharged from the melter. The noble metals, Fe, and Al were the components that significantly slowed down or stopped the accumulation …
Date: December 17, 2010
Creator: Matyas, Josef; Vienna, John D.; Schaible, Micah J.; Rodriguez, Carmen P.; Crum, Jarrod V.; Arrigoni, Alyssa L. et al.
Object Type: Report
System: The UNT Digital Library
PACE and the Federal Housing Finance Agency (FHFA) (open access)

PACE and the Federal Housing Finance Agency (FHFA)

The FHFA regulates Fannie Mae, Freddie Mac, and the 12 Federal Home Loan Banks (the government-sponsored enterprises - GSEs). On June 18, 2009, James B. Lockhart III, then Director of FHFA, released a letter expressing concern about the negative impact of energy loan tax assessment programs (ELTAPs) - also known as Property Assessed Clean Energy (PACE) programs - on both the housing finance system and homeowner program participants. Subsequently, a number of PACE proponents responded to the concerns laid out in the FHFA letter. In early Fall 2009, word circulated that FHFA was planning to follow its June letter with guidance to other agencies, possibly including Fannie Mae and Freddie Mac, discouraging them from buying loans on properties subject to PACE-type assessment liens. This triggered a second round of stakeholder letters, several of which were addressed to President Obama. On October 18, 2009, the White House, in what some believe was an attempt to obviate the need for FHFA guidance, released a Policy Framework for PACE Financing Programs that outlined best practices guidance for homeowner and lender protection. As of February 2010, FHFA and the GSEs have agreed to monitor PACE programs and work with stakeholders and the Administration to …
Date: March 17, 2010
Creator: Zimring, Mark & Fuller, Merrian
Object Type: Report
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop: Progress in High-pT Physics at RHIC (open access)

Proceedings of RIKEN BNL Research Center Workshop: Progress in High-pT Physics at RHIC

This volume archives the presentations at the RIKEN BNL Research Center workshop 'Progress in High-PT Physics at RHIC', held at BNL in March 2010. Much has been learned from high-p{sub T} physics after 10 years of RHIC operations for heavy-ion collisions, polarized proton collisions and d+Au collisions. The workshop focused on recent progress in these areas by both theory and experiment. The first morning saw review talks on the theory of RHIC high-p{sub T} physics by G. Sterman and J. Soffer, and on the experimental results by M. Tannenbaum. One of the most exciting recent results from the RHIC spin program is the first observation of W bosons and their associated single-spin asymmetry. The new preliminary data were reported on the first day of our workshop, along with a theoretical perspective. There also were detailed discussions on the global analysis of polarized parton distributions, including the knowledge on gluon polarization and the impact of the W-data. The main topic of the second workshop day were single-transverse spin asymmetries and their analysis in terms of transverse-momentum dependent parton distributions. There is currently much interest in a future Drell-Yan program at RHIC, thanks to the exciting physics opportunities this would offer. This …
Date: March 17, 2010
Creator: Bazilevsky, A.; Bland, L. & Vogelsang, W.
Object Type: Report
System: The UNT Digital Library
Progress Report, December 2010: Improved Site Characterization And Storage Prediction Through Stochastic Inversion Of Time-Lapse Geophysical And Geochemical Data (open access)

Progress Report, December 2010: Improved Site Characterization And Storage Prediction Through Stochastic Inversion Of Time-Lapse Geophysical And Geochemical Data

Over the last project six months, our project activities have concentrated on three areas: (1) performing a stochastic inversion of pattern 16 seismic data to deduce reservoir permeability, (2) development of the geochemical inversion strategy and implementation of associated software, and (3) completing the software implementation of TProGS and the geostatistical analysis that provides the information needed when using the software to produce realizations of the Midale reservoir. The report partially the following deliverables: D2: Model development: MCMC tool (synthetic fluid chemistry data); deliverable completed. D4: Model development/verification: MCMC tool (TProGS, field seismic/chemistry data) work product; deliverable requirements partially fulfilled. D5: Field-based single-pattern simulations work product; deliverable requirements partially fulfilled. When completed, our completed stochastic inversion tool will explicitly integrate reactive transport modeling, facies-based geostatistical methods, and a novel stochastic inversion technique to optimize agreement between observed and predicted storage performance. Such optimization will be accomplished through stepwise refinement of: (1) the reservoir model - principally its permeability magnitude and heterogeneity - and (2) geochemical parameters - primarily key mineral volume fractions and kinetic data. We anticipate that these refinements will facilitate significantly improved history matching and forward modeling of CO{sub 2} storage. Our tool uses the Markov Chain Monte …
Date: December 17, 2010
Creator: Ramirez, A.; Mcnab, W.; Carle, S.; Hao, Y.; White, D. & Johnson, J.
Object Type: Report
System: The UNT Digital Library
Low Cost, Durable Seal (open access)

Low Cost, Durable Seal

Seal durability is critical to achieving the 2010 DOE operational life goals for both stationary and transportation PEM fuel cell stacks. The seal material must be chemically and mechanically stable in an environment consisting of aggressive operating temperatures, humidified gases, and acidic membranes. The seal must also be producible at low cost. Currentlyused seal materials do not meet all these requirements. This project developed and demonstrated a high consistency hydrocarbon rubber seal material that was able to meet the DOE technical and cost targets. Significant emphasis was placed on characterization of the material and full scale molding demonstrations.
Date: December 17, 2010
Creator: Roberts, George; Parsons, Jason & Friedman, Jake
Object Type: Report
System: The UNT Digital Library
ZINC MITIGATION INTERIM REPORT - THERMODYNAMIC STUDY (open access)

ZINC MITIGATION INTERIM REPORT - THERMODYNAMIC STUDY

An experimental program was initiated in order to develop and validate conditions that will effectively trap Zn vapors that are released during extraction. The proposed work is broken down into three tasks. The first task is to determine the effectiveness of various pore sizes of filter elements. The second task is to determine the effect of filter temperature on zinc vapor deposition. The final task is to determine whether the zinc vapors can be chemically bound. The approach for chemically binding the zinc vapors has two subtasks, the first is a review of literature and thermodynamic calculations and the second is an experimental approach using the best candidates. This report details the results of the thermodynamic calculations to determine feasibility of chemically binding the zinc vapors within the furnace module, specifically the lithium trap (1). A review of phase diagrams, literature, and thermodynamic calculations was conducted to determine if there are suitable materials to capture zinc vapor within the lithium trap of the extraction basket. While numerous elements exist that form compounds with zinc, many of these also form compounds with hydrogen or the water that is present in the TPBARs. This relatively comprehensive review of available data indicates that …
Date: December 17, 2010
Creator: Korinko, P.
Object Type: Report
System: The UNT Digital Library
Development of Extraction Techniques for the Detection of Signature Lipids from Oil (open access)

Development of Extraction Techniques for the Detection of Signature Lipids from Oil

Pure cultures, including Desulfovibrio vulgaris and Methanococcus maripaludus, were combined with model oil samples and oil/diesel mixtures to optimize extraction techniques of signature lipids from oil in support of investigation of microbial communities in oil deposit samples targets for microbial enhanced hydrocarbon recovery. Several techniques were evaluated, including standard phospholipid extraction, ether linked lipid for Archaeal bacterial detection, and high pressure extractiontechniques. Recovery of lipids ranged from 50-80percent as compared to extraction of the pure culture. Extraction efficiency was evaluated by the use of internal standards. Field samples will also be tested for recovery of signature lipids with optimized extraction techniques.
Date: May 17, 2010
Creator: Borglin, Sharon; Geller, Jil; Chakraborty, Romy; Hazen, Terry & Mason, Olivia
Object Type: Report
System: The UNT Digital Library
EFFECT OF PORE SIZE ON TRAPPING ZINC VAPORS (open access)

EFFECT OF PORE SIZE ON TRAPPING ZINC VAPORS

A series of experiments were conducted to determine the effect of pore size on pumping efficiency and zinc vapor trapping efficiency. A simple pumping efficiency test was conducted for all five pore diameters where it was observed that evacuation times were adversely affected by reducing the pore size below 5 {micro}m. Common test conditions for the zinc trapping efficiency experiments were used. These conditions resulted in some variability, to ascribe different efficiencies to the filter media. However, the data suggest that there is no significant difference in trapping efficiency for filter media with pores from 0.2 to 20 {micro}m with a thickness of 0.065-inch. Consequently, the 20 {micro}m pore filter media that is currently used at SRS is a suitable filter material for to utilize for future extractions. There is evidence that smaller pore filter will adversely affect the pumping times for the TEF and little evidence to suggest that a smaller pore diameters have significant impact on the trapping efficiency.
Date: December 17, 2010
Creator: Korinko, P.
Object Type: Report
System: The UNT Digital Library
Water use in the development and operation of geothermal power plants. (open access)

Water use in the development and operation of geothermal power plants.

Geothermal energy is increasingly recognized for its potential to reduce carbon emissions and U.S. dependence on foreign oil. Energy and environmental analyses are critical to developing a robust set of geothermal energy technologies. This report summarizes what is currently known about the life cycle water requirements of geothermal electric power-generating systems and the water quality of geothermal waters. It is part of a larger effort to compare the life cycle impacts of large-scale geothermal electricity generation with other power generation technologies. The results of the life cycle analysis are summarized in a companion report, Life Cycle Analysis Results of Geothermal Systems in Comparison to Other Power Systems. This report is divided into six chapters. Chapter 1 gives the background of the project and its purpose, which is to inform power plant design and operations. Chapter 2 summarizes the geothermal electricity generation technologies evaluated in this study, which include conventional hydrothermal flash and binary systems, as well as enhanced geothermal systems (EGS) that rely on engineering a productive reservoir where heat exists but water availability or permeability may be limited. Chapter 3 describes the methods and approach to this work and identifies the four power plant scenarios evaluated: a 20-MW EGS …
Date: September 17, 2010
Creator: Clark, C. E.; Harto, C. B.; Sullivan, J. L.; Wang, M. Q. (Energy Systems) & EVS), (
Object Type: Report
System: The UNT Digital Library

Effect of Increasing Nitrogen Deposition on Soil Microbial Communities

Increasing nitrogen deposition, increasing atmospheric CO2, and decreasing biodiversity are three main environmental changes occurring on a global scale. The BioCON (Biodiversity, CO2, and Nitrogen) ecological experiment site at the University of Minnesota's Cedar Creek Ecosystem Science Reserve started in 1997, to better understand how these changes would affect soil systems. To understand how increasing nitrogen deposition affects the microbial community diversity, heterogeneity, and functional structure impact soil microbial communities, 12 samples were collected from the BioCON plots in which nitrogenous fertilizer was added to simulate the effect of increasing nitrogen deposition and 12 samples from without added fertilizer. DNA from the 24 samples was extracted using a freeze-grind protocol, amplified, labeled with a fluorescent dye, and then hybridized to GeoChip, a functional gene array containing probes for genes involved in N, S and C cycling, metal resistance and organic contaminant degradation. Detrended correspondence analysis (DCA) of all genes detected was performed to analyze microbial community patterns. The first two axes accounted for 23.5percent of the total variation. The samples fell into two major groups: fertilized and non-fertilized, suggesting that nitrogenous fertilizer had a significant impact on soil microbial community structure and diversity. The functional gene numbers detected in fertilized …
Date: May 17, 2010
Creator: Xiao, Shengmu; Xue, Kai; He, Zhili; VanNostrand, Joy D.; Liu, Jianshe; Hobbie, Sarah E. et al.
Object Type: Poster
System: The UNT Digital Library
Development of High Average Power Lasers for the Photon Collider (open access)

Development of High Average Power Lasers for the Photon Collider

The laser and optics system for the photon collider seeks to minimize the required laser power by using an optical stacking cavity to recirculate the laser light. An enhancement of between 300 to 400 is desired. In order to achieve this the laser pulses which drive the cavity must precisely match the phase of the pulse circulating within the cavity. We report on simulations of the performance of a stacking cavity to various variations of the drive laser in order to specify the required tolerances of the laser system. We look at the behavior of a simple four mirror cavity as shown in Fig. 1. As a unit input pulse is applied to the coupling mirror a pulse begins to build up in the interior of the cavity. If the drive pulses and the interior pulse arrive at the coupling mirror in phase the interior pulse will build up to a larger value. The achievable enhancement is a strong function of the reflectivity of the cavities. The best performance if attained when the reflectivities of the input coupler is matched to the internal reflectivities of the cavity. In Fig. 2 we show the build up of the internal pulse after …
Date: May 17, 2010
Creator: Gronberg, J; Stuart, B & Seryi, A
Object Type: Article
System: The UNT Digital Library