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Evaluation of thermal energy storage materials for advanced compressed air energy storage systems

Description: Advanced Compressed-Air Energy Storage (ACAS) plants have the near-term potential to reduce the fuel consumption of compressed-air plants from 33 to 100%, depending upon their design. Fuel is saved by storing some or all of the heat of compression as sensible heat which is subsequently used to reheat the compressed air prior to expansion in the turbine generator. The thermal storage media required for this application must be low cost and durable. The objective of this project was to screen thermal store materials based on their thermal cycle durability, particulate formation and corrosion resistant characteristics. The materials investigated were iron oxide pellets, Denstone pebbles, cast-iron balls, and Dresser basalt rock. The study specifically addressed the problems of particle formation and thermal ratcheting of the materials during thermal cycling and the chemical attack on the materials by the high temperature and moist environment in an ACAS heat storage bed. The results indicate that from the durability standpoint Denstone, cast iron containing 27% or more chromium, and crushed Dresser basalt would possibly stand up to ACAS conditions. If costs are considered in addition to durability and performance, the crushed Dresser basalt would probably be the most desirable heat storage material for adiabatic and hybrid ACAS plants, and more in-depth longer term thermal cycling and materials testing of Dresser basalt is recommended. Also recommended is the redesign and costing analysis of both the hybrid and adiabatic ACAS facilities based upon the use of Dresser basalt as the thermal store material.
Date: March 1, 1983
Creator: Zaloudek, F.R.; Wheeler, K.R. & Marksberry, L.
Partner: UNT Libraries Government Documents Department

A document preparation system in a large network environment

Description: At Los Alamos National Laboratory, we have developed an integrated document preparation system that produces publication-quality documents. This system combines text formatters and computer graphics capabilities that have been adapted to meet the needs of users in a large scientific research laboratory. This paper describes the integration of document processing technology to develop a system architecture, based on a page description language, to provide network-wide capabilities in a distributed computing environment. We describe the Laboratory requirements, the integration and implementation issues, and the challenges we faced developing this system.
Date: January 1, 1988
Creator: Vigil, M.; Bouchier, S.; Sanders, C.; Sydoriak, S. & Wheeler, K.
Partner: UNT Libraries Government Documents Department

Analysis of bacterial spore permeability to water and ions using Nano-Secondary Ion Mass Spectrometry (NanoSIMS)

Description: Regulation of bacterial spore solvent and solute permeability is a fundamental feature of dormancy but is poorly understood. Here we present a new technique, nano-scale secondary ion mass spectrometry (NanoSIMS) that allows the direct visualization and quantification of chemical gradients within spores. Using NanoSIMS, we demonstrate the penetration of water and a simple ionic salt, LiF, into the core of Bacillus thuringiensis israelensis (Bti) spores. The results demonstrate chemical gradients spanning the outer coat to the inner spore core that are driven by concentration-dependent ionic fluxes. Using deuterated water (D{sub 2}O), we have shown that external water is either retained or exchanged with water contained within the spore. Hydration and exchange are rapid, on a timescale of < 1 minute. Our results suggest a permeation mechanism by which short-time scale diffusion into and out of the spore can occur along hydration pathways. Additional studies are in progress to define the flux rates and mechanisms controlling these processes.
Date: November 17, 2005
Creator: Ghosal, S; Fallon, S; Leighton, T; Wheeler, K; Hutcheon, I & Weber, P K
Partner: UNT Libraries Government Documents Department

Multi-Probe Investigation of Proteomic Structure of Pathogens

Description: Complete genome sequences are available for understanding biotransformation, environmental resistance and pathogenesis of microbial, cellular and pathogen systems. The present technological and scientific challenges are to unravel the relationships between the organization and function of protein complexes at cell, microbial and pathogens surfaces, to understand how these complexes evolve during the bacterial, cellular and pathogen life cycles, and how they respond to environmental changes, chemical stimulants and therapeutics. In particular, elucidating the molecular structure and architecture of human pathogen surfaces is essential to understanding mechanisms of pathogenesis, immune response, physicochemical interactions, environmental resistance and development of countermeasures against bioterrorist agents. The objective of this project was to investigate the architecture, proteomic structure, and function of bacterial spores through a combination of high-resolution in vitro atomic force microscopy (AFM) and AFM-based immunolabeling with threat-specific antibodies. Particular attention in this project was focused on spore forming Bacillus species including the Sterne vaccine strain of Bacillus anthracis and the spore forming near-neighbor of Clostridium botulinum, C. novyi-NT. Bacillus species, including B. anthracis, the causative agent of inhalation anthrax are laboratory models for elucidating spore structure/function. Even though the complete genome sequence is available for B. subtilis, cereus, anthracis and other species, the determination and composition of spore structure/function is not understood. Prof. B. Vogelstein and colleagues at the John Hopkins University have recently developed a breakthrough bacteriolytic therapy for cancer treatment (1). They discovered that intravenously injected Clostridium novyi-NT spores germinate exclusively within the avascular regions of tumors in mice and destroy advanced cancerous lesions. The bacteria were also found to significantly improve the efficacy of chemotherapeutic drugs and radiotherapy (2,3). Currently, there is no understanding of the structure-function relationships of Clostridium novyi-NT spores. As well as their therapeutic interest, studies of Clostridium noyii spores could provide a model for further studies of ...
Date: January 24, 2008
Creator: Malkin, A J; Plomp, M; Leighton, T J; Vogelstein, B & Wheeler, K E
Partner: UNT Libraries Government Documents Department

In vitro high-resolution structural dynamics of single germinating bacterial spores

Description: Although significant progress has been achieved in understanding the genetic and biochemical bases of the spore germination process, the structural basis for breaking the dormant spore state remains poorly understood. We have used atomic force microscopy (AFM) to probe the high-resolution structural dynamics of single Bacillus atrophaeus spores germinating under native conditions. Here we show that AFM can reveal previously unrecognized germination-induced alterations in spore coat architecture and topology as well as the disassembly of outer spore coat rodlet structures. These results and previous studies in other microorganisms suggest that the spore coat rodlets are structurally similar to amyloid fibrils. AFM analysis of the nascent surface of the emerging germ cell revealed a porous network of peptidoglycan fibers. The results are consistent with a honeycomb model structure for synthetic peptidoglycan oligomers determined by nuclear magnetic resonance. AFM is a promising experimental tool for investigating the morphogenesis of spore germination and cell wall peptidoglycan structure.
Date: November 14, 2006
Creator: Plomp, M; Leighton, T; Wheeler, K & Malkin, A
Partner: UNT Libraries Government Documents Department

Bioforensics: Characterization of biological weapons agents by NanoSIMS

Description: The anthrax attacks of Fall 2001 highlight the need to develop forensic methods based on multiple identifiers to determine the origin of biological weapons agents. Genetic typing methods (i.e., DNA and RNA-based) provide one attribution technology, but genetic information alone is not usually sufficient to determine the provenance of the material. Non-genetic identifiers, including elemental and isotopic signatures, provide complementary information that can be used to identify the means, geographic location and date of production. Under LDRD funding, we have successfully developed the techniques necessary to perform bioforensic characterization with the NanoSIMS at the individual spore level. We have developed methods for elemental and isotopic characterization at the single spore scale. We have developed methods for analyzing spore sections to map elemental abundance within spores. We have developed rapid focused ion beam (FIB) sectioning techniques for spores to preserve elemental and structural integrity. And we have developed a high-resolution depth profiling method to characterize the elemental distribution in individual spores without sectioning. We used these newly developed methods to study the controls on elemental abundances in spores, characterize the elemental distribution of in spores, and to study elemental uptake by spores. Our work under this LDRD project attracted FBI and DHS funding for applied purposes.
Date: February 26, 2007
Creator: Weber, P K; Ghosal, S; Leighton, T J; Wheeler, K E & Hutcheon, I D
Partner: UNT Libraries Government Documents Department

Solid state storage of radioactive krypton in a silica matrix

Description: The feasibility of loading a low density SiO/sub 2/ glass with krypton for storage of radioactive /sup 85/Kr has been demonstrated by studies using non-radioactive krypton. A 96% SiO/sub 2/ glass with 28% porosity was heated at an elevated pressure of Kr gas to a temperature of 850 to 900/sup 0/C and held at that temperature to sinter the glass-krypton composite to a density of about 2 g/cm/sup 3/. A krypton content of 30 cm/sup 3/ of Kr(STP)/cm/sup 3/ of glass has been demonstrated when loading pressures of 140 MPa are used. Krypton release rates from the glass are lower than reported for any other waste form considered currently. At 420/sup 0/C a diffusion parameter, D/r/sub 0//sup 2/, of 8.66 x 10/sup -13/ min/sup -1/ was determined which leads to a total release of 0.7% of the krypton in 10 years. Release rates increase moderately with increasing temperature up to 600/sup 0/C and increase rapidly above 600/sup 0/C. The lower loading pressures (about 40 MPa) may appear to yield a more favorable product from the point of view of krypton release than the high pressures. Advantages and disadvantages of the technique are given in the conclusions section.
Date: December 1, 1980
Creator: Tingey, G.L.; Lytle, J.M.; Gray, W.J. & Wheeler, K.R.
Partner: UNT Libraries Government Documents Department

Deposition and corrosion phenomena on aluminum surfaces under deluged dry cooling-tower condisions. Interim report

Description: Deposition and corrosion on aluminum heat exchanger surfaces resulting from deluge in wet/dry cooling towers is simulated in a laboratory Corrosion/Deposition Loop (CDL). Heat exchanger deposition buildup was found to be linearly dependent on concentration factor and number of wet/dry cycles. Deionized water rising after deluge reduced rate of deposition. Laboratory data obtained from CDL relates directly to operation of the Advanced Concepts Test (ACT) demonstration cooling tower. Technology transferable to ACT shows that deposition from supersaturated solution can be effectively controlled by attention to water chemistry, pH, water conditioning, and good heat transfer design. The additional mechanism of deposition by water film evaporation is effectively managed by soft water rinsing and uniform surface wetting. Exposure of a model TRANE surface (the ACT wet/dry exchanger) produced short-term deposition extrapolating to 0.011 mm buildup in three years. Studies continue to verify 4X as maximum cycles of concentration through control of water chemistry and rinsing after deluge. Deluge water used at ACT facility is sufficiently aggressive to warrant use of Alclad to extend tube service life.
Date: July 1, 1981
Creator: Wheeler, K.R.; May, R.P.; Douglas, J.G. & Tylczak, J.H.
Partner: UNT Libraries Government Documents Department

Bacillus atrophaeus Outer Spore Coat Assembly and Ultrastructure

Description: Our previous atomic force microscopy (AFM) studies successfully visualized native Bacillus atrophaeus spore coat ultrastructure and surface morphology. We have shown that the outer spore coat surface is formed by a crystalline array of {approx}11 nm thick rodlets, having a periodicity of {approx}8 nm. We present here further AFM ultrastructural investigations of air-dried and fully hydrated spore surface architecture. In the rodlet layer, planar and point defects, as well as domain boundaries, similar to those described for inorganic and macromolecular crystals, were identified. For several Bacillus species, rodlet structure assembly and architectural variation appear to be a consequence of species-specific nucleation and crystallization mechanisms that regulate the formation of the outer spore coat. We propose a unifying mechanism for nucleation and self-assembly of this crystalline layer on the outer spore coat surface.
Date: November 21, 2005
Creator: Plomp, M; Leighton, T J; Wheeler, K E; Pitesky, M E & Malkin, A J
Partner: UNT Libraries Government Documents Department