416 research outputs found
Interplay of air and sand: Faraday heaping unravelled
We report on numerical simulations of a vibrated granular bed including the effect of the ambient air, generating the famous Faraday heaps known from experiment. A detailed analysis of the forces shows that the heaps are formed and stabilized by the airflow through the bed while the gap between bed and vibrating bottom is growing, confirming the pressure gradient mechanism found experimentally by Thomas and Squires [Phys. Rev. Lett. 81, 574 (1998)], with the addition that the airflow is partly generated by isobars running parallel to the surface of the granular bed. Importantly, the simulations also explain the heaping instability of the initially flat surface and the experimentally observed coarsening of a number of small heaps into a larger one
Inversion of Chladni patterns by tuning the vibrational acceleration\ud
Inverse Chladni patterns, i.e., grains collecting at the antinodes of a resonating plate, are traditionally believed to occur only when the particles are small enough to be carried along by the ambient air. We now show—theoretically and numerically—that air currents are not the only mechanism leading to inverse patterns: When the acceleration of the resonating plate does not exceed g, particles will always roll to the antinodes, irrespective of their size, even in the absence of air. We also explain why this effect has hitherto escaped detection in standard Chladni experiment
Weiterentwicklung der hydrothermalen Karbonisierung zur CO2-sparenden und kosteneffizienten Trocknung von Klärschlamm im industriellen Massstab sowie der Rückgewinnung von Phosphor
In Switzerland, sewage sludge has to be burned since 2006. So far the necessary drying was done by thermal methods with high inputs of energy. In this project we investigate hydrothermal carbonisation (HTC) as CO2 saving and cost efficient alternative to dry sewage sludge on industrial scale. The focus in this applied research project is on the process water treatment, the mechanical dewatering, the potential use of HTC coal, the recycling of phosphorus and heavy metals and an assessment of environmental effects of HTC compared to current treatments.
The potential for biological decomposition was investigated in HTC process water and permeat, which was gained by membrane filtration of HTC process water. A medium to high decomposition rate was shown for organic matter in HTC process water and permeat by aerobic and anaerobic processes in batch experiments. In a continuous aerobic laboratory reactor the HTC process water and permeat showed decomposition rates of 70-75% for chemical oxygen demand (COD) at a specific load of 5-10 kg COD/(m3 reactor volume*d). In the competition for a HTC-stage at the Oftringen waste water treatment plant (WWTP) an increase of dissolved organic carbon (DOC) due to the addition of HTC-permeate is limited to 3 mg/l in the effluent of the WWTP. This value can be reached by an optimised membrane filtration with no further treatment for most cases.
Advantages of HTC for the mechanical dewatering were shown with a filter press on industrual scale. HTC coal was successfully burned in mono- and mixed combustion plants on industrial scale, for example at Jura Cement in Wildegg or the sludge combustion plant (SVA) in Winterthur. At SVA additional fossil fuels could be temporarily fully substituted by HTC coal. Additional experiments on industrial scale are planned. No evidence of decreased recycling capability of phosphorus or heavy metals after carbonisation was found.
Compared to the currently applied sewage sludge drying process the waste heat could be reduced by up to 62% and the electricity demand by up to 69% with HTC. A detailled life cycle assessment showed little differences of HTC compared to the thermal drying process with waste heat but significant advantages compared to the thermal process of drying with fossil fuels. HTC is most promising concerning minimal environmental effects if optimizing measures are applied such as the reduction of phosphorus and nitrogen in the HTC process water, the recycling of phosphorus and the use of lost heat, renewable energy sources such as sewage gas, wood chips, green electricity on adequate sites and if the produced HTC coal is used as substitute of fossil fuels, for example in cement industry or brown coal power plants.
Currently a detailled technical study is prepared by AVA-CO2 and another competitor for the first industrial HTC plant in Switzerland to dry sewage sludge at the WWTP Oftringen
Safe Haven in Deutschland? Handlungsoptionen für Bergungsorte bedrohter Kulturgüter
Angesichts zunehmender Gefährdungen von Kulturgütern weltweit durch bewaffnete Konflikte und Krisen unterschiedlichen Ursprungs und Ausmaßes stellt sich die drängende Frage, wie diese kulturelle Essenz mit Bedeutung für die gesamte Menschheit wirkungsvoll
geschützt werden kann. Wenn alle Schutzvorkehrungen im Herkunftsland versagen, bleibt oft nur die Evakuierung im Katastrophenfall. Um geborgenes Kulturgut
vorübergehend sicher zu verwahren, können nach internationalem Recht Bergungsorte, sogenannte Safe Haven, eingerichtet und angeboten werden. Die vorliegende Studie untersucht entsprechende Ausgestaltungsmöglichkeiten
Snapshots on simulation games in academic contexts
Simulation games originate from strategic, scenario-based planning; they are playful, interactive and participatory methods or formats designed to train multiple competences, ranging from simple, instantly performed role plays to complex simulations lasting several days or weeks. Simulation games either focus on prototypal imitations of real/existing situations or events (simulation), or address archetypal scenarios of fundamental problems or conflicts (planspiel). In academic contexts simulation games become increasingly popular and relevant. They appeal to our gaming nature as homo ludens; they call for an essential academic freedom to act; and they provide novel, innovative and adaptive learning arrangements
LINNAEUS: A species name identification system for biomedical literature
<p>Abstract</p> <p>Background</p> <p>The task of recognizing and identifying species names in biomedical literature has recently been regarded as critical for a number of applications in text and data mining, including gene name recognition, species-specific document retrieval, and semantic enrichment of biomedical articles.</p> <p>Results</p> <p>In this paper we describe an open-source species name recognition and normalization software system, LINNAEUS, and evaluate its performance relative to several automatically generated biomedical corpora, as well as a novel corpus of full-text documents manually annotated for species mentions. LINNAEUS uses a dictionary-based approach (implemented as an efficient deterministic finite-state automaton) to identify species names and a set of heuristics to resolve ambiguous mentions. When compared against our manually annotated corpus, LINNAEUS performs with 94% recall and 97% precision at the mention level, and 98% recall and 90% precision at the document level. Our system successfully solves the problem of disambiguating uncertain species mentions, with 97% of all mentions in PubMed Central full-text documents resolved to unambiguous NCBI taxonomy identifiers.</p> <p>Conclusions</p> <p>LINNAEUS is an open source, stand-alone software system capable of recognizing and normalizing species name mentions with speed and accuracy, and can therefore be integrated into a range of bioinformatics and text-mining applications. The software and manually annotated corpus can be downloaded freely at <url>http://linnaeus.sourceforge.net/</url>.</p
Removal of hydrogen from Ti VT 1-0 under action of accelerated electrons
The process of hydrogen removal from titanium of VT1-0 grade under the action of accelerated electrons has been studied experimentally. The irradiation was carried out by an electron beam with energies of 25-40 keV during 15-60 min. The information on the hydrogen content in samples from titanium of VT1-0 grade has been obtained both before and after irradiation with accelerated electrons. The activation energy of hydrogen desorption from titanium has been calculated. It was found that the increase of the time and the energy of an irradiation lead to the decrease of the residual hydrogen content in the titanium samples
iTAP, a novel iRhom interactor, controls TNF secretion by policing the stability of iRhom/TACE
The apical inflammatory cytokine TNF regulates numerous important biological processes including inflammation and cell death, and drives inflammatory diseases. TNF secretion requires TACE (also called ADAM17), which cleaves TNF from its transmembrane tether. The trafficking of TACE to the cell surface, and stimulation of its proteolytic activity, depends on membrane proteins, called iRhoms. To delineate how the TNF/TACE/iRhom axis is regulated, we performed an immunoprecipitation/mass spectrometry screen to identify iRhom-binding proteins. This identified a novel protein, that we name iTAP (iRhom Tail-Associated Protein) that binds to iRhoms, enhancing the cell surface stability of iRhoms and TACE, preventing their degradation in lysosomes. Depleting iTAP in primary human macrophages profoundly impaired TNF production and tissues from iTAP KO mice exhibit a pronounced depletion in active TACE levels. Our work identifies iTAP as a physiological regulator of TNF signalling and a novel target for the control of inflammation.info:eu-repo/semantics/publishedVersio
praxiSDG & Next Practices for Sustain|Ability: Exploring Experiential Patterns for Transformative Learning through Service
What helps to understand transformative learning in sustain|ability contexts? Experiences may explain how transform|ability fuels sustain|ability in transfer contexts. The adopted research design explores patterns of documented transformational learning in competency-driven and sustainability-induced opportunities. Sustain|ability results from the ability to transform by creating next practices of learning and doing/acting/performing. praxiSDG promotes transform|ability as process designed for initiating and motivating change, and by sparking off transformational potential through involving empowering, action-driven competencies.
praxiSDG as a living lab activates hands-on transformational competencies by and in sustainability-related campus-community partnerships. To this, Sustainable Development Goals (SDGs) provide guidance for practical experiences and didactic reflection regarding learners’ transform|ability in third-mission contexts. How does transformational service learning succeed in sustain|ability? That is at the core of the corresponding research based on qualitative, theoretically grounded portfolio analysis and principles of teaching and learning. The following conceptions – next practices of learning and doing, transformational competencies, campus-community partnerships, patterns of sustainability, and third mission – are framing the research agenda for transform|ability through sustain|ability. This sheds light on two related questions, namely, first, what patterns from experience help understanding how transformative learning can succeed in a sustainability context and, secondly, what research design can be used to investigate this
MOA-2010-BLG-477Lb: constraining the mass of a microlensing planet from microlensing parallax, orbital motion and detection of blended light
Microlensing detections of cool planets are important for the construction of
an unbiased sample to estimate the frequency of planets beyond the snow line,
which is where giant planets are thought to form according to the core
accretion theory of planet formation. In this paper, we report the discovery of
a giant planet detected from the analysis of the light curve of a
high-magnification microlensing event MOA-2010-BLG-477. The measured
planet-star mass ratio is and the projected
separation is in units of the Einstein radius. The angular
Einstein radius is unusually large mas. Combining
this measurement with constraints on the "microlens parallax" and the lens
flux, we can only limit the host mass to the range . In
this particular case, the strong degeneracy between microlensing parallax and
planet orbital motion prevents us from measuring more accurate host and planet
masses. However, we find that adding Bayesian priors from two effects (Galactic
model and Keplerian orbit) each independently favors the upper end of this mass
range, yielding star and planet masses of
and at a distance of kpc,
and with a semi-major axis of AU. Finally, we show that the
lens mass can be determined from future high-resolution near-IR adaptive optics
observations independently from two effects, photometric and astrometric.Comment: 3 Tables, 12 Figures, accepted in Ap
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