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Modes of Action and Functions of ERECTA-family Receptor-like Kinases in Plant Organ Growth and Development

Description: Higher plants constitute the central resource for renewable lignocellulose biomass that can supplement for the world's depleting stores of fossil fuels. As such, understanding the molecular and genetic mechanisms of plant organ growth will provide key knowledge and genetic resources that enables manipulation of plant biomass feedstock for better growth and productivity. The goal of this proposal is to understand how cell proliferation and growth are coordinated during aboveground organ morphogenesis, and how cell-cell signaling mediated by a family of receptor kinases coordinates plant organogenesis. The well-established model plant Arabidopsis thaliana is used for our research to facilitate rapid progress. Specifically, we focus on how ERECTA-family leucine-rich repeat receptor kinases (LRR-RLKs) interact in a synergistic manner to promote organogenesis and pattern formation in Arabidopsis. This project was highly successful, resulted in fourteen publications including nine peer-reviewed original research articles. One provisional US patent has been filed through this DOE funding. We have addressed the critical roles for a family of receptor kinases in coordinating proliferation and differentiation of plants, and we successfully elucidated the downstream targets of this signaling pathway in specifying stomatal patterning.
Date: May 1, 2012
Creator: TORII, Keiko U.
Partner: UNT Libraries Government Documents Department

A systematic investigation of PET Radionuclide Specific Activity on Miniaturization of Radiochemistry

Description: The PET radionuclides, 18F and 11C consist of very high radiation to mass amounts and should be easily adapted to new technologies such as “chip chemistry” with nanofluidics. However, environmental contamination with nonradioactive fluorine, carbon and other trace contaminants add sufficient mass, micrograms to milligrams, to prevent adapting PET radiochemistry to the nanochip technologies. In addition, the large volumes of material required for beam irradiation make it necessary to also remove the 18F and 11C from their chemical matrices. These steps add contaminants. The work described in this report was a systematic investigation of sources of these contaminants and methods to reduce these contaminants and the reaction volumes for radiochemical synthesis. Several methods were found to lower the contaminants and matrices to within a factor of 2 to 100 of those needed to fully implement chip technology but further improvements are needed.
Date: March 8, 2012
Creator: Link, Jeanne M.
Partner: UNT Libraries Government Documents Department

A High Resolution Monolithic Crystal, DOI, MR Compatible, PET Detector

Description: The principle objective of this proposal is to develop a positron emission tomography (PET) detector with depth-of-interaction (DOI) positioning capability that will achieve state of the art spatial resolution and sensitivity performance for small animal PET imaging. When arranged in a ring or box detector geometry, the proposed detector module will support <1 mm3 image resolution and >15% absolute detection efficiency. The detector will also be compatible with operation in a MR scanner to support simultaneous multi-modality imaging. The detector design will utilize a thick, monolithic crystal scintillator readout by a two-dimensional array of silicon photomultiplier (SiPM) devices using a novel sensor on the entrance surface (SES) design. Our hypothesis is that our single-ended readout SES design will provide an effective DOI positioning performance equivalent to more expensive dual-ended readout techniques and at a significantly lower cost. Our monolithic crystal design will also lead to a significantly lower cost system. It is our goal to design a detector with state of the art performance but at a price point that is affordable so the technology can be disseminated to many laboratories. A second hypothesis is that using SiPM arrays, the detector will be able to operate in a MR scanner without any degradation in performance to support simultaneous PET/MR imaging. Having a co-registered MR image will assist in radiotracer localization and may also be used for partial volume corrections to improve radiotracer uptake quantitation. The far reaching goal of this research is to develop technology for medical research that will lead to improvements in human health care.
Date: March 6, 2012
Creator: Miyaoka, Robert S
Partner: UNT Libraries Government Documents Department

Physical Properties of Hanford Transuranic Waste

Description: The research described herein was undertaken to provide needed physical property descriptions of the Hanford transuranic tank sludges under conditions that might exist during retrieval, treatment, packaging and transportation for disposal. The work addressed the development of a fundamental understanding of the types of systems represented by these sludge suspensions through correlation of the macroscopic rheological properties with particle interactions occurring at the colloidal scale in the various liquid media. The results of the work have advanced existing understanding of the sedimentation and aggregation properties of complex colloidal suspensions. Bench scale models were investigated with respect to their structural, colloidal and rheological properties that should be useful for the development and optimization of techniques to process the wastes at various DOE sites.
Date: March 25, 2010
Creator: Berg, John C.
Partner: UNT Libraries Government Documents Department

Physical Characterization of Solid-Liquid Slurries at High Weight Fractions Utilizing Optical and Ultrasonic Methods

Description: The goal of this proposed work is to directly address the need for rapid on-line characterization of the physical properties of HLW slurries during all phases of the remediation process, from in-tank characterization of sediments to monitoring of the concentration, particle size, and degree of agglomeration and gelation of slurries during transport. There are three tasks: (1) develop new optical and acoustic scattering measurements to provide the fundamental science needed for successful device development and implementation, (2) develop theories that describe the interrelationship between wave propagation and the physical properties of the slurry, and (3) perform inversions of the theories and compare them with the experimental measurements to non-intrusively characterize slurries.
Date: June 1, 2005
Creator: Burgess, Lloyd W.
Partner: UNT Libraries Government Documents Department

Physical Properties of Hanford Transuranic Waste Sludge

Description: Equipment that was purchased in the abbreviated year 1 of this project has been used during year 2 to study the fundamental behavior of materials that simulate the behavior of the Hanford transuranic waste sludge. Two significant results have been found, and each has been submitted for publication. Both studies found non-DLVO behavior in simulant systems. These separate but related studies were performed concurrently. It was previously shown in Rassat et al.'s report Physical and Liquid Chemical Simulant Formulations for Transuranic Wastes in Hanford Single-Shell Tanks that colloidal clays behave similarly to transuranic waste sludge (PNNL-14333, National Technical Information Service, U.S. Dept. of Commerce). Rassat et al. also discussed the pH and salt content of actual waste materials. It was shown that these materials exist at high pHs, generally above 10, and at high salt content, approximately 1.5 M from a mixture of different salts. A type of clay commonly studied, due to its uniformity, is a synthetic hectorite, Laponite. Therefore the work performed over the course of the last year was done mainly using suspensions of Laponite at high pH and involving high salt concentrations. One study was titled ''Relating Clay Rheology to Colloidal Parameters''. It has been submitted to the Journal of Colloid and INterface Science and is currently in the review process. The idea was to gain the ability to use measurable quantities to predict the flow behavior of clay systems, which should be similar to transuranic waste sludge. Leong et al. had previously shown that the yield stress of colloidal slurries of titania and alumina could be predicted, given the measurement of the accessible parameter zeta potential (Leong YK et al. J Chem Soc Faraday Trans, 19 (1993) 2473). Colloidal clays have a fundamentally different morphology and surface charge distribution than the spheroidal, uniformly charged colloids ...
Date: June 1, 2005
Creator: Berg, John C.
Partner: UNT Libraries Government Documents Department

DE-FG02-04ER63746 FinalTechnicalReport

Description: This is the final technical report for a project involving the study of stress response systems in the radiation-resistant bacterium, Deinococcus radiodurans. Three stresses of importance for a mixed waste treatment strain were studied, heat shock, solvent shock, and phosphate starvation. In each case, specific genes involved in the ability to survive the stress were identified using a systems biology approach, and analysis of mutants was used to understand mechanisms. This study has led to increased understanding of the ways in which a potential treatment strain could be manipulated to survive multiple stresses for treatment of mixed wastes.
Date: September 5, 2009
Creator: Lidstrom, M.E.
Partner: UNT Libraries Government Documents Department

DE-FG02-96ER20226 FinalTechnicalReport

Description: In the future, environmental concerns will mandate that manufacturing processes shift towards the use of renewable resources and the minimization of wastes, especially hazardous wastes. One-carbon compounds are of interest as feedstocks for synthesis of chemicals and materials, because they represent a relatively inexpensive, abundant and renewable resource. In addition, the environmentally-benign characteristics of microbial processes make them of interest as part of a long-term waste-minimization strategy for industry. The concept that methylotrophic bacteria could serve as non-polluting multistage catalysts to generate chemicals and materials using C1 compounds as feedstocks is a highly attractive one. In order to develop production strains of methylotrophs, it is necessary to understand and manipulate central methylotrophic pathways. One of the most important of these is the methanol oxidation, or Mox system. In this project, we are studying the promoters and transcriptional regulation of this 25-gene system in Methylobacterium extorquens AM1, a facultative methanol-utilizer. We have addressed the significance of a hexanucleotide sequence upstream of all mox promoters and have shown that it is required for activity of these promoters using both deletion and mutational analyses. In addition, we have identified a putative hairpin structure in the RNA leader region of the mxa promoter that is also essential for transcriptional, and have assessed the mechanism of action of this regulatory region. This work is providing the foundation for development of methylotrophic strains to convert methanol into higher value added products.
Date: September 5, 2009
Creator: Lidstrom, M E
Partner: UNT Libraries Government Documents Department

Genetic Engineering of Plants to Improve Phytoremediation of Chlorinated Hydrocarbons in Groundwater

Description: I. Mechanism of halogenated hydrocarbon oxidation We are using poplar culture cells to determine the pathway of TCE metabolism. In our earlier work, we found that trichloroethanol (TCEOH) is a major early intermediate. Our studies this year have focused on the steps that follow this toxic intermediate. We did several experiments to track the disappearance of TCEOH after the cells were removed from TCE. We could conclude that TCEOH is not an end-product but is rapidly degraded. Six flasks of poplar liquid suspension cells were exposed to a level of 50 {micro}g/ml TCE for three days. Three of the cultures were subjected to MTBE extractions to quantify the levels of TCEOH produced. The cells of the remaining three cultures were then pelleted and resuspended in fresh medium. After three more days, these were also subjected to MTBE extractions. The samples were analyzed by GC-ECD. After the three days of further metabolism, an average of 91% of the trichloroethanol was gone. When similar experiments were done with intact plants and both free and conjugated TCEOH were quantified, a similar rapid decline in both forms was seen (Shang, 2001). Therefore, it seems probable that similar mechanisms are taking place in both poplar suspension cells and whole poplar plants, so we continued to do our studies with the suspension cells. Metabolism of trichloroethanol may go through trichloroacetic acid (TCAA) prior to dehalogenation. To test this possibility, we exposed cells to TCE and analyzed for TCAA over time. The cultures were analyzed after 4, 5, 6, and 14 days from TCE exposure. We did not detect any significant amount of TCAA above the background in undosed cells. To determine if trichloroethanol itself is directly dehalogenated, we analyzed TCE-exposed cells for the presence of dichloroethanol. Undosed cells did not have any of the DCEOH peak ...
Date: December 1, 2004
Creator: Strand, Stuart E.
Partner: UNT Libraries Government Documents Department

Investigating Ultrasonic Diffraction Grating Spectroscopy and Reflection Techniques for Characterizing Slurry Properties

Description: The U.S. Department of Energy (DOE) has millions of gallons of radioactive liquid and sludge wastes that must be retrieved from underground storage tanks. This waste, in the form of slurries, must be transferred and processed to a final form, such as glass logs. On-line instrumentation to measure the properties of these slurries in real-time during transport is needed in order to prevent plugging and reduce excessive dilution. The results, describes a collaborative effort between Pacific Northwest National Laboratory (PNNL) and the University of Washington to develop a completely new method for using ultrasonics to measure the particle size and viscosity of a slurry. The concepts are based on work in optics on grating-light-reflection spectroscopy (GLRS) at the University of Washington and work on ultrasonic diffraction grating spectroscopy (UDGS) carried out at PNNL. The objective of the research was to extend the GLRS theory for optics to ultrasonics, and to demonstrate its capabilities of UDGS. The proposed ultrasonic method could result in an instrument that would be simple, rugged, and very compact, allowing it to be implemented as part of a pipeline wall at facilities across the DOE complex
Date: December 15, 2005
Creator: Burgess, L.W. & Brodsky, A.M.
Partner: UNT Libraries Government Documents Department

Physical Characterization of Solid-Liquid Slurries at High Weight Fractions Using Optical and Ultrasonic Methods

Description: Remediation of highly radioactive waste is a major technical and programmatic challenge for the DOE. Rapid, on-line physical characterization of highly concentrated slurries is required for the safe and efficient remediation of 90 million gallons of high level radioactive waste (HLW), sodium bearing waste, and mixed waste. The research presented here, describes a collaborative effort between Pacific Northwest National Laboratory (PNNL) and the University of Washington (UW) to directly address the need for rapid on-line characterization of the physical properties of HLW slurries during all phases of the remediation process, from in-tank characterization of sediments to monitoring of the concentration, particle size, and degree of agglomeration and gelation of slurries during transport. Near-surface characterization of the slurry flow in the particle size range from nanometer to micrometer is examined using optical low coherence reflectometry. Volumetric characterization at depths in the slurry flow, up to several centimeters in the particle size range from the micrometer to millimeter, is realized by utilizing ultrasonic backscatter and diffuses fields. One of the strengths, the teaming up of significant talents in both experimental and theoretical optics and in ultrasonics, provides a synergistic approach to integrate these complimentary techniques. One of the benefits of this combined approach is the physical characterization of HLW over a concentration and particle size range that is broader than can be achieved with today's technology. This will avoid a costly increase in waste stream volume due to excess dilution, and will lessen chance of plugging pipes that could shut down expensive processing lines.
Date: December 22, 2005
Creator: Burgess, L.W.; Brodsky, A.M. & P.D., Panetta
Partner: UNT Libraries Government Documents Department

Evaluation of the 1997 Joint National Conference, Women in Engineering Program Advocates Network (WEPAN) and National Association of Minority Engineering Program Administrators (NAMEPA)

Description: The primary goal of the 1997 Joint National Conference was to unite NAMEPA and WEPAN in a unique collaborative effort to further the cause of increasing the participation of women and minorities in science and engineering. The specific objectives were to: (1) conduct technical and programmatic seminars for institutions desiring to initiate, replicate, or expand women and minorities in engineering program; (2) provide assistance in fundraising and grant writing; (3) profile women in engineering programs of excellence; (4) sponsor inspiring knowledgeable and motivational keynote speakers; and (5) offer a series of workshops focused on a multitude of topics.
Date: July 1, 1997
Creator: Brainard, Suzanne G.
Partner: UNT Libraries Government Documents Department

Chemical Speciation of Inorganic Compounds under Hydrothermal Conditions

Description: This project utilizes the high-intensity x-rays available at the Advance Photon Source (APS) to study the inorganic chemistry associated with tank waste vitrification. Although the chemical conversion of waste under high-temperature conditions is an integral part of these processing technologies, there is virtually no information in the published literature about the chemical speciation of inorganic compounds under actual processing conditions. This is primarily due to the lack of techniques that are capable of making in situ measurements of aqueous systems above 300 C. The ongoing x-ray-based studies are identifying the chemical species, oxidation states and ion pairing of inorganic compounds under extreme solvent conditions. It is imperative to make in situ measurements since we have shown that the chemical speciation is strongly dependent on temperature. Several complimentary techniques are being used in this study including x-ray absorption fine structure (XAFS), diffuse anomalous x-ray scattering (DAS) and vibrational (IR & Raman) spectroscopy. Thus, the results of this work are providing information critical to the calcining and vitrification of tank wastes. The results will also have a direct bearing on specific issues such as volatility of Tc (or Re) compounds and the complex chemistry of chromium compounds.
Date: June 1, 2000
Creator: Stern, Edward A.; Fulton, John L. & Seidler,Gerald
Partner: UNT Libraries Government Documents Department

Characterization and Correlation of Particle-Level Interactions to the Macroscopic Rheology of Powders, Granular Slurries, and Colloidal Suspensions

Description: This project had two primary objectives. The first was to understand the physical properties and behavior of select Hanford tank sludges under conditions that might exist during retrieval, treatment, packaging, and transportation for disposal at the Waste Isolation Pilot Plant (WIPP). The second objective was to develop a fundamental understanding of these sludge suspensions by correlating the macroscopic properties with particle interactions occurring at the colloidal scale. The specific tank wastes considered herein are contained in thirteen Hanford tanks including three double-shell tanks (DSTs) (AW-103, AW-105, and SY-102) and ten single-shell tanks (SSTs) (B-201 through B-204, T-201 through T-204, T-110, and T-111). At the outset of the project, these tanks were designated as potentially containing transuranic (TRU) process wastes that would be treated and disposed of in a manner different from the majority of the tank wastes.
Date: September 29, 2006
Creator: Poloski, A.P.; Daniel, R.C.; Rector, D.R.; Bredt, P.R.; Buck, E.C.; Berg, J.C. et al.
Partner: UNT Libraries Government Documents Department

Physical Characterization of Solid-Liquid Slurries at High Weight Fractions Using Optical and Ultrasonic Methods

Description: The goal of this proposed work is to directly address the need for rapid on-line characterization of the physical properties of HLW slurries during all phases of the remediation process, from in-tank characterization of sediments to monitoring of the concentration, particle size, and degree of agglomeration and gelation of slurries during transport. This will be done with both optical and ultrasonic methods. There are three tasks: (1) develop optical and acoustic measurements to provide the fundamental science needed for successful device development and implementation, (2) develop theories that describe the interrelationship between wave propagation and the physical properties of the slurry, and (3) solve, in the framework of these theories, the inversion problem and compare them with the experimental measurements to non-intrusively characterize slurries.
Date: May 28, 2002
Creator: Burgess, L. W.; Brodsky, A. M.; Panetta, P. D.; Pappas, R. A.; Bond, L. J. & Bamberger, J. A.
Partner: UNT Libraries Government Documents Department

Physical Characterization of Solid-Liquid Slurries at High Weight Fractions Using Optical and Ultrasonic Methods

Description: The goal of this proposed work is to directly address the need for rapid on-line characterization of the physical properties of HLW slurries during all phases of the remediation process, from in-tank characterization of sediments to monitoring of the concentration, particle size, and degree of agglomeration and gelation of slurries during transport. Current technologies are not capable of characterizing the HLW waste stream without dilution. The results from this work will be utilized to develop new methodologies to characterize the HLW stream in-situ. There are three tasks: (1) develop new optical and acoustic scattering measurements to provide the fundamental science needed for successful device development and implementation, (2) develop theories that describe the interrelationship between wave propagation and the physical properties of the slurry, and (3) perform inversions of the theories and compare them with the experimental measurements to non-intrusively characterize slurries.
Date: June 15, 2004
Creator: Burgess, L. W.; Brodsky, A. M.; Panetta, P. D.; Pappas, R. A.; Ahmed, S. & Tucker, B.
Partner: UNT Libraries Government Documents Department

Cell multipole method for molecular simulations in bulk and confined systems

Description: One of the bottlenecks in molecular simulations is to treat large systems involving electrostatic interactions. Computational time in conventional molecular simulation methods scales with O(N{sup 2}), where N is the number of atoms. With the emergence of the cell multipole method (CMM) and massively parallel supercomputers, simulations of 10 million atoms have been performed. In this work, the optimal hierarchy cell level and the algorithm for Taylor expansion were recommended for fast and accurate molecular dynamics (MD) simulations of three-dimensional (3D) systems. CMM was then extended to treat quasi-two-dimensional (2D) systems, which is very important for condensed matter physics problems. In addition, CMM was applied to grand canonical ensemble Monte Carlo (GCMC) simulations for both 3D and 2D systems. Under the optimal conditions, the results show that computational time is approximately linear with N for large systems, average error in total potential energy is less than {approx}1%, and RMS force is about 0.015 for 3D and 2D systems when compared with the Ewald summation.
Date: August 2002
Creator: Zheng, Jie; Balasundaram, Ramkumar; Gehrke, Stevin H.; Heffelfinger, Grant S.; Goddard, William A. III & Jiang, Shaoyi
Partner: UNT Libraries Government Documents Department