540 research outputs found
Präzise Absolutmessung der Aktivität von Tritium-II: Eigenschaften und Konstruktion von Internal-Gas-Zählrohren für Absolutmessungen, inbesondere von tritiereten Wasserstoff-Methan-Zählgasen. EUR 1400-2. = Precise absolute measurement of the activity of tritium II: Properties and construction of internal gas counting tubes for absolute measurements, particularly of titrated hydrogen-methane counting gases. EUR 1400-2.
Präzise Absolutmessung der Aktivität von Tritium-I: Wasserstoffdarstellung und Herstellung der Zählgases. EUR 1400-1. = Precise absolute measurement of the activity of tritium-I: Hydrogen notation and preparation of the counting gas. EUR 1400-1.
Präzise Absolutmessung der Aktivität von Tritium-III: Absolutzählung von Tritium im Internal-Gas-Zählrohrer. EUR 1400-3. = Precise absolute measurement of the activity of tritium III: absolute counting of tritium in the internal gas counting tubes. EUR 1400-3.
Crowdsourcing for Creating a Dataset for Training a Medication Chatbot
To facilitate interaction with mobile health applications, chatbots are increasingly used. They realize the interaction as a dialog where users can ask questions and get answers from the chatbot. A big challenge is to create a comprehensive knowledge base comprising patterns and rules for representing possible user queries the chatbot has to understand and interpret. In this work, we assess how crowdsourcing can be used for generating examples of possible user queries for a medication chatbot. Within one week, the crowdworker generated 2'738 user questions. The examples provide a large variety of possible formulations and information needs. As a next step, these examples for user queries will be used to train our medication chatbot
Thermal neutron induced (n,p) and (n,alpha) reactions on 37Ar
The 37Ar(n_th,alpha)34S and 37Ar(n_th,p)37Cl reactions were studied at the
high flux reactor of the ILL in Grenoble. For the 37Ar(n_th,alpha_0) and
37Ar(n_th,p) reaction cross sections, values of (1070+/-80)b and (37+/-4)b,
respectively, were obtained. Both values are about a factor 2 smaller than
results of older measurements. The observed suppression of the 37(n_th,alpha_1)
transition could be verified from theoretical considerations. Finally, evidence
was found for the two-step 37Ar(n_th,gamma-alpha) process.Comment: 11 pages, 5 figures, accepted for publication in Nuclear Physics
Sulfur incorporation in high level nuclear waste glass: a S K-edge XAFS investigation
We perform X-ray absorption fine structure (XAFS) spectroscopy measurements at the sulfur K-edge to elucidate the electronic and geometric bonding of sulfur atoms in borosilicate glass used for the vitrification of high level radioactive liquid waste. The sulfur is incorporated as sulfate, most probably as sodium sulfate, which can be deduced from the X-ray absorption near edge structure (XANES) by fingerprint comparison with reference compounds. This finding is backed up by Raman spectroscopy investigation. In the extended XAFS data, no second shell beyond the first oxygen layer is visible. We argue that this is due to the sulfate being present as small clusters located into voids of the borosilicate network. Hence, destructive interference of the variable surrounding prohibits the presence of higher shell signals. The knowledge of the sulfur bonding characteristics is essential for further optimization of the glass composition and to balance the requirements of the process and glass quality parameters, viscosity and electrical resistivity on one side, waste loading and sulfur uptake on the other side
Discovery of a new genus of anaerobic ammonium oxidizing bacteria with a mechanism for oxygen tolerance
In the past 20 years, there has been a major stride in understanding the core mechanism of anaerobic ammonium-oxidizing (anammox) bacteria, but there are still several discussion points on their survival strategies. Here, we discovered a new genus of anammox bacteria in a full-scale wastewater-treating biofilm system, tentatively named “Candidatus Loosdrechtia aerotolerans”. Next to genes of all core anammox metabolisms, it encoded and transcribed genes involved in the dissimilatory nitrate reduction to ammonium (DNRA), which coupled to oxidation of small organic acids, could be used to replenish ammonium and sustain their metabolism. Surprisingly, it uniquely harbored a new ferredoxin-dependent nitrate reductase, which has not yet been found in any other anammox genome and might confer a selective advantage to it in nitrate assimilation. Similar to many other microorganisms, superoxide dismutase and catalase related to oxidative stress resistance were encoded and transcribed by “Ca. Loosdrechtia aerotolerans”. Interestingly, bilirubin oxidase (BOD), likely involved in oxygen resistance of anammox bacteria under fluctuating oxygen concentrations, was identified in “Ca. Loosdrechtia aerotolerans” and four Ca. Brocadia genomes, and its activity was demonstrated using purified heterologously expressed proteins. A following survey of oxygen-active proteins in anammox bacteria revealed the presence of other previously undetected oxygen defense systems. The novel cbb3-type cytochrome c oxidase and bifunctional catalase-peroxidase may confer a selective advantage to Ca. Kuenenia and Ca. Scalindua that face frequent changes in oxygen concentrations. The discovery of this new genus significantly broadens our understanding of the ecophysiology of anammox bacteria. Furthermore, the diverse oxygen tolerance strategies employed by distinct anammox bacteria advance our understanding of their niche adaptability and provide valuable insight for the operation of anammox-based wastewater treatment systems
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