Chemistry and Materials Science, A Collection of Articles from Science & Technology Review (open access)

Chemistry and Materials Science, A Collection of Articles from Science & Technology Review

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Date: February 5, 2003
Creator: Diaz de la Rubia, T
System: The UNT Digital Library
Characterization of Plutonium, Neptunium, Strontium on Manganese Solids from Permanganate Reduction (open access)

Characterization of Plutonium, Neptunium, Strontium on Manganese Solids from Permanganate Reduction

This report reviews work relevant to Mn oxides and their use in radionuclide decontamination, focuses on the mechanism of radionuclide decontamination during permanganate treatment with simulant SRS HLW salt solutions and characterizes the solids that form.
Date: February 5, 2003
Creator: Duff, M.O.
System: The UNT Digital Library
Radiolytic Bubble Gas Hydrogen Compositions (open access)

Radiolytic Bubble Gas Hydrogen Compositions

Radioactive waste solids can trap bubbles containing hydrogen that may pose a flammability risk if they are disturbed and hydrogen is released. Whether a release is a problem or not depends, among other things, on the hydrogen composition of the gas. This report develops a method for estimating the hydrogen composition of trapped bubbles based on waste properties.
Date: February 5, 2003
Creator: Hester, J. R.
System: The UNT Digital Library
Novel Yersinia Pestis Toxin that Resembles Bacillus Anthracis Edema Factor: Study of Activity and Structural Modeling (open access)

Novel Yersinia Pestis Toxin that Resembles Bacillus Anthracis Edema Factor: Study of Activity and Structural Modeling

The goal of this project was to begin both experimental and computational studies of the novel plague toxin to establish its biological properties and create its 3D-model. The project was divided into two parts. (1) Experimental--This part was devoted to determine distribution of the genes encoding novel plague toxin among different isolates of Y.pestis. If the EF-like activity is important for Y.pestis pathogenicity, it is anticipated that all highly virulent strains will contain the toxin genes. Also, they proposed to initiate research to investigate the functionality of the novel Y.pestis toxin that they hypothesize is likely to significantly contribute to the virulence of this dangerous microbe. this research design consisted of amplification, cloning and expression in E.coli the toxin genes followed by affinity purification of the recombinant protein that can be further used for testing of enzymatic activity. (2) Computational--The structural modeling of the putative EF of Y.pestis was based on multiple sequence alignments, secondary structure predictions, and comparison with 3D models of the EF of B. anthracis. The x-ray structure of the last has been recently published [Nature. 2002. 415(Jan):396-402]. The final model was selected after detailed analysis to determine if the structure is consistent with the biological function.
Date: February 5, 2003
Creator: Motin, V; Garcia, E; Barsky, D & Zemla, A
System: The UNT Digital Library
High Level Waste Demonstration of the Caustic-Side Solvent Extraction Process with Optimized Solvent in the 2-CM Centrifugal Contactor Apparatus Using Tank 37H/44F Supernate (open access)

High Level Waste Demonstration of the Caustic-Side Solvent Extraction Process with Optimized Solvent in the 2-CM Centrifugal Contactor Apparatus Using Tank 37H/44F Supernate

This report summarizes the results of tests at Savannah River Technology Center with radioactively spiked simulated Tank 37H/44F waste and actual Tank 37H/44F supernate composite waste. The spiked simulant tests demonstrated that stable hydraulic conditions could be maintained with the new solvent formulation and the radioactive feed could be decontaminated to background levels. The 24 hour actual Tank 37H/44F waste test demonstrated similar hydraulic stability and higher decontamination factors.
Date: February 5, 2003
Creator: Norato, M. A.
System: The UNT Digital Library
Optics, Diagnostics and Applications for Fourth-Generation Light Sources (open access)

Optics, Diagnostics and Applications for Fourth-Generation Light Sources

The Linac Coherent Light Source (LCLS) is a 1.5 to 15 {angstrom}-wavelength free-electron laser (FEL), proposed for the Stanford Linear Accelerator Centre (SLAC). The photon output consists of high brightness, transversely coherent pulses with duration < 300 fs, together with a broad spontaneous spectrum with total power comparable to the coherent output. The output fluence, and pulse duration, pose special challenges for optical component and diagnostic designs. We first discuss the specific requirements for the initial scientific experiments, and our proposed solutions. We then describe the supporting research and development program that includes: (1) radiation field modeling, (2) experimental and theoretical material damage studies, (3) high resolution, high fluence-tolerant optical design, fabrication, and testing, (including material manufacturing), and (4) diagnostic design and testing.
Date: February 5, 2003
Creator: Wootton, A.; Barbee, T.; Bionta, R.; Chapman, H.; Ditmire, T.; Dyer, G. et al.
System: The UNT Digital Library