779 research outputs found
Application of Electron-Attachment Reactions to Enhance Selectivity of Electron-Capture Detector for Nitroaromatic Explosives
The differences in the extent of electron-attachment reactions between thermal electrons and selected classes of organic molecules with high electron affinities were investigated. the investigations showed that interactions of thermal electrons with nitroaromatic compounds lead to the formation of neutral products with very low electron affinities. by contrast, a number of other analytes with high electron affinities such as polyhalogenated organic compounds, lead to products with high electron affinities. This difference was exploited to differentiate between nitroaromatic and polychlorinated organic compounds with a tandem arrangement consisting of two electron-capture detectors connected in series with an electron-attachment reactor
Characterization of shed medicinal leech mucus reveals a diverse microbiota
Microbial transmission through mucosal-mediated mechanisms is widespread throughout the animal kingdom. One example of this occurs with Hirudo verbana, the medicinal leech, where host attraction to shed conspecific mucus facilitates horizontal transmission of a predominant gut symbiont, the Gammaproteobacterium Aeromonas veronii. However, whether this mucus may harbor other bacteria has not been examined. Here, we characterize the microbiota of shed leech mucus through Illumina deep sequencing of the V3-V4 hypervariable region of the 16S rRNA gene. Additionally, Restriction Fragment Length Polymorphism (RFLP) typing with subsequent Sanger Sequencing of a 16S rRNA gene clone library provided qualitative confirmation of the microbial composition. Phylogenetic analyses of full-length 16S rRNA sequences were performed to examine microbial taxonomic distribution. Analyses using both technologies indicate the dominance of the Bacteroidetes and Proteobacteria phyla within the mucus microbiota. We determined the presence of other previously described leech symbionts, in addition to a number of putative novel leech-associated bacteria. A second predominant gut symbiont, the Rikenella-like bacteria, was also identified within mucus and exhibited similar population dynamics to A. veronii, suggesting persistence in syntrophy beyond the gut. Interestingly, the most abundant bacterial genus belonged to Pedobacter, which includes members capable of producing heparinase, an enzyme that degrades the anticoagulant, heparin. Additionally, bacteria associated with denitrification and sulfate cycling were observed, indicating an abundance of these anions within mucus, likely originating from the leech excretory system. A diverse microbiota harbored within shed mucus has significant potential implications for the evolution of microbiomes, including opportunities for gene transfer and utility in host capture of a diverse group of symbionts
RADBIOMOD: A simple program for utilising biological modelling in radiotherapy plan evaluation
Abstract not availableJoe H. Chang, Christopher Gehrke, Ramachandran Prabhakar, Suki Gill, Morikatsu Wada, Daryl Lim Joon, Vincent Kho
ERIGrid Holistic Test Description for Validating Cyber-Physical Energy Systems
Smart energy solutions aim to modify and optimise the operation of existing energy infrastructure. Such cyber-physical technology must be mature before deployment to the actual infrastructure, and competitive solutions will have to be compliant to standards still under development. Achieving this technology readiness and harmonisation requires reproducible experiments and appropriately realistic testing environments. Such testbeds for multi-domain cyber-physical experiments are complex in and of themselves. This work addresses a method for the scoping and design of experiments where both testbed and solution each require detailed expertise. This empirical work first revisited present test description approaches, developed a newdescription method for cyber-physical energy systems testing, and matured it by means of user involvement. The new Holistic Test Description (HTD) method facilitates the conception, deconstruction and reproduction of complex experimental designs in the domains of cyber-physical energy systems. This work develops the background and motivation, offers a guideline and examples to the proposed approach, and summarises experience from three years of its application.This work received funding in the European Community’s Horizon 2020 Program (H2020/2014–2020)
under project “ERIGrid” (Grant Agreement No. 654113)
Finitely generated free Heyting algebras via Birkhoff duality and coalgebra
Algebras axiomatized entirely by rank 1 axioms are algebras for a functor and
thus the free algebras can be obtained by a direct limit process. Dually, the
final coalgebras can be obtained by an inverse limit process. In order to
explore the limits of this method we look at Heyting algebras which have mixed
rank 0-1 axiomatizations. We will see that Heyting algebras are special in that
they are almost rank 1 axiomatized and can be handled by a slight variant of
the rank 1 coalgebraic methods
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Dig-face monitoring during excavation of a radioactive plume at Mound Laboratory, Ohio
A dig-face monitoring system consists of onsite hardware for collecting information on changing chemical, radiological, and physical conditions in the subsurface soil during the hazardous site excavation. A prototype dig-face system was take to Mount Laboratory for a first trial. Mound Area 7 was the site of historical disposals of {sup 232}Th, {sup 227}Ac, and assorted debris. The system was used to monitor a deep excavation aimed at removing {sup 227}Ac-contaminated soils. Radiological, geophysical, and topographic sensors were used to scan across the excavation dig-face at four successive depths as soil was removed. A 3-D image of the contamination plumes was developed; the radiation sensor data indicated that only a small portion of the excavated soil volume was contaminated. The spatial information produced by the dig-face system was used to direct the excavation activities into the area containing the {sup 227}Ac and to evaluate options for handling the separate {sup 232}Th plume
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Mapping of contamination at Savannah River Site FBWU by INEEL trolley
The Ford Building Waste Unit (FBWU) 643-11G is a Resource Conservation and Recovery Act/Comprehensive Environmental Response Compensation and Liability Act (RCRA/CERCLA) designated site at the Savannah River Site (SRS) in Aiken, South Carolina. Pre-Work Plan Characterization at the FBWU in May 1996 indicated that radiological contamination was present in surface and near surface soils and identified cesium-137, {sup 137}Cs, the unit specific contaminant, as being primarily in the top 15 cm of soil. The Idaho National Engineering and Environmental Laboratory (INEEL) sent the dig-face trolley system to SRS where it demonstrated its capability over a 6.1-m (20 ft.) x 9.6-m (30 ft.) area to rapidly map the contamination on-line with its large area plastic scintillation detector. Also, an extended-range (10 keV to 3 MeV) Ge detector was used at selected locations to identify and quantify the {sup 137}Cs contamination. The coordinate locations of each measurement acquired in either the scanning or fixed position mode was obtained with a survey system based on radial encoders. Topography measurements were also made during measurements to permit correction of field of view and activity concentrations for changes in the ground to detector distance
A-site Ordering versus Electronic Inhomogeneity in CMR-Manganite Films
Epitaxial La3/4Ca1/4MnO3/MgO(100) (LCMO) thin films show unusual rhombohedral
(R-3c) structure with a new perovskite superstructure due to unique ordering of
La and Ca at the A-site positions. Very sharp insulator-metal and
para-ferromagnetic phase transitions at temperatures up to TMI ~ TC=295 K were
observed. The ordered films were electronically homogeneous down to 1 nm scale
as revealed by scanning tunnelling microscopy/spectroscopy. In contrast,
orthorhombic and A-site disordered LCMO demonstrate broadened phase transitions
as well as mesoscopic phase separation for T<<TC. The unique La/Ca ordering
suppresses cation mismatch stress within one super-cell, a~1.55 nm, enhancing
electronic homogeneity. Phase separation scenario seems not to be a unique
mechanism for CMR as very large CMR=500 % was also observed in A-site ordered
films.Comment: We have added two references and additional sentence
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