13 research outputs found
Homogeneity assessment of Swiss snow depth series: comparison of break detection capabilities of (semi-)automatic homogenization methods
Nosocomial Outbreak of Parechovirus 3 Infection among Newborns, Austria, 2014
In 2014, sepsis-like illness affected 9 full-term newborns in 1 hospital in Austria. Although results of initial microbiological testing were negative, electron microscopy identified picornavirus. Archived serum samples and feces obtained after discharge were positive by PCR for human parechovirus 3. This infection should be included in differential diagnoses of sepsis-like illness in newborns
Quantifying the influence of refreezing meltwater on the mass balance and runoff of Freya Glacier, North-East-Greenland
Das Wiedergefrieren von Schmelzwasser in kalten arktischen Schneedecken spielt eine bedeutende Rolle in der Massen- und Energiebilanz arktischer Gletscher, da es zu einem systematischen Fehler fĂŒhrt sofern es nicht berĂŒcksichtigt wird. Jenes Schmelzwasser, dass bis zum Grund der Schneedecke sickert, friert direkt an der GletscheroberflĂ€che wieder an und bildet Aufeis. In dieser Arbeit werden die Ergebnisse der durchgefĂŒhrten Messungen und Modellierungen des Wiedergefrierens von Schmelzwasser in der Schneedecke von Freya Gletscher gezeigt. Er ist ein polythermaler, 5.3 km2 groĂer Talgletscher auf Clavering Island in Nordost Grönland, nahe der dĂ€nischen Forschungsstation Zackenberg. Seine OberflĂ€che ist nach Nordwesten ausgerichtet und erstreckt sich zwischen 330 bis 1250 m Seehöhe. FĂŒr die Untersuchungen wurde eine Stelle im flachen Schneesumpf-Gebiet nahe der Gleichgewichtslinie ausgewĂ€hlt. Zur Sammlung der notwendigen Daten zur Berechnung der Energiebilanz wurden Eis- und Schneetemperatursensoren installiert und eine Automatische Wetterstation aufgebaut. Die gesammelten Daten wurden fĂŒr das eindimensionale physikalisch-basierte Schneemodell SNOWPACK verwendet, dass zur Untersuchung des Wiedergefrierens des Schmelzwassers und der Quantifizierung der Bildung von Aufeis genutzt wurde. Die Ergebnisse zeigen die Bildung von 10 - 15 cm Aufeis wegen dem Wiedergefrieren von Schmelzwasser auf der GletscheroberflĂ€che in der Ablationsperiode zwischen Juni Juli. Ein Vergleich mit den Temperaturmessungen zeigte die FĂ€higkeit von SNOWPACK zur Modellierung einer arktischen Schneedecke mit glaubwĂŒrdigen Ergebnissen. Sie zeigen, dass die modellierte Menge des Aufeises sehr wahrscheinlich ist. Wenn der Firn nicht abschmilzt, schĂŒtzt er das darunter befindliche Aufeis, welches in der Folge zur Akkumulation beitrĂ€gt. Eine AbschĂ€tzung fĂŒr die Bedeutung des Einflusses auf die Massenbilanz zeigt einen Beitrag zwischen 6 - 9 % zur Akkumulation der modellierten Saison.Refreezing of melt water in the cold snowpack is known to play an important role both in the mass and energy budgets of Arctic glaciers as it leads to a systematic error if not accounted for. Meltwater percolating to the bottom of the snowpack will refreeze directly onto the glacier, forming superimposed ice. In this thesis, results of performed observations and modelling of refreezing of meltwater in the snowpack of Freya Glacier are shown. It is a polythermal, 5.3 km2 small mountain glacier situated on Clavering Island in North-East Greenland, close to the Danish research station Zackenberg. Its surface is north-west oriented, reaching from 330 m to 1250 m a.s.l. For the research, a location in a flat slush-ice area near the equilibrium line was chosen. For gathering all necessary data for energy balance calculations, ice and snow temperature sensors were installed as well as an automatic weather station was put up. These data served as input for the one-dimensional physical-based snow model SNOWPACK, which was used to investigate the refreezing of melt water in the snow pack and quantify the formation of superimposed ice. Results show the formation of about 10 - 15 cm superimposed ice because of effective meltwater refreeze upon the glacier surface during the ablation period in June and July. Bias-analysis of snow temperature reveal show SNOWPACKs ability for modelling the Arctic snowpack with reliable results. The findings lead to the conclusion that the modelled formation of superimposed ice is very likely. If the firn does not completely vanish during the ablation it prevents the formed superimposed ice beneath from melting, which subsequently contributes to the accumulation. A spatial quantification for assessing the influence on the mass balance shows a contribution between 6 - 9 % to the accumulation in the modelled season.submitted by Gernot Resch, BScZusammenfassungen in Deutsch und EnglischKarl-Franzens-UniversitĂ€t Graz, Masterarbeit, 2018(VLID)258143
Bioinspired fracture toughness enhancement of a fully bio-based epoxy resin
In this work, the concept of fracture toughness improvement via spatial variation of mechanical properties is applied to a composite with 100% bio-based carbon content based on epoxidized linseed oil. By proper selection of the hardener, either citric acid or sebacic acid, the mechanical properties were adjusted in a way that a bio-composite exhibits a stiff-soft-stiff layer architecture. Samples with two different thicknesses of soft interlayer (approx. 0.1Â mm and 1.3Â mm) were subsequently analyzed regarding their final performance. Specimen characteristics, owing to the curing and manufacturing process, were analyzed by means of local Fourier-transform infrared spectroscopy and differential scanning calorimetry. Fracture mechanics tests were performed to verify if the soft interlayer acts as a crack arrester. The results propose a high chemical compatibility between the used epoxy resins. Embedding a soft thin interlayer into a stiff resin matrix led to an increase in fracture toughness of 13 times, compared to the pure stiff resin. An increase in interlayer thickness led to a further increase in fracture toughness of 24 times. However, the stiffness decreased by 44% and 67%, respectively
Atomic force microscopy studies of ZnS films grown on (100) GaAs by the successive ionic layer adsorption and reaction method
Nosocomial Outbreak of Parechovirus 3 Infection among Newborns, Austria, 2014
In 2014, sepsis-like illness affected 9 full-term newborns in 1 hospital in Austria. Although results of initial microbiological testing were negative, electron microscopy identified picornavirus. Archived serum samples and feces obtained after discharge were positive by PCR for human parechovirus 3. This infection should be included in differential diagnoses of sepsis-like illness in newborns