411 research outputs found

    Latent Heat Fluxes over Complex Terrain from Airborne Water Vapour and Wind Lidars

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    Tropospheric profiles of water vapour and wind were measured with a differential absorption lidar (DIAL) and a heterodyne detection Doppler wind lidar collo-cated onboard the DLR Falcon research aircraft in the past two years. The DIAL is a newly developed four-wavelength system operating on three water vapour absorption lines of different strengths, one offline wavelength at 935 nm (each 50 Hz, 40 mJ), and 532 and 1064 nm for aerosol profiling. It is designed as an airborne demonstrator for a possible future space-borne water vapour lidar mission. It operated success-fully during the Convective and Orographically-induced Precipitation Study (COPS) in July 2007 over the Black Forest Mountains in southern Germany, and during the Norwegian THORPEX-IPY field experiment in March 2008 over the European North Sea. For the study of summertime convection initiation over complex terrain and the development of Polar Lows in the North Sea both campaigns included latent heat flux missions where both airborne lidars were pointed nadir-viewing. Using eddy-correlation of the remotely-sensed wind and water vapour fluctuations, a repre-sentative flux profile can be obtained from a single over-flight of the area under investigation. The lidars’ spatial resolution is ~200 m which resolves the domi-nant circulation and flux patterns in a convective boundary layer. This novel instrumentation allows ob-taining profiles of the latent heat flux beneath the air-craft from one single over-flight of any area of interest

    Acute gallbladder perforation with gallstones spillage in a cirrhotic patient

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    Gallbladder perforation is a rare complication of cholecystitis and cholelithiasis. The high morbidity and mortality rates associated with this condition are due to delays in diagnosis and treatment since signs and symptoms of perforation do not differ significantly from those of uncomplicated cholecystitis. We report on a patient who was affected by Child-Pugh A alcoholic liver cirrhosis and who developed an acute gallbladder perforation with spillage of stones into the peritoneal cavity and give a review of the current literature

    Improvements in flexibility depending on stretching duration

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    International Journal of Exercise Science 16(4): 83-94, 2023. To improve flexibility, stretching is most commonly used and in training interventions duration-dependent effects are hypothesized. However, there are strong limitations in used stretching protocols in most studies, particularly regarding documentation of intensity and performed procedure. Thus, aim of this study was to compare different stretching durations on flexibility in the plantar flexors and to exclude potential biases. Eighty subjects were divided into four groups performing daily stretching training of 10min (IG10), 30min (IG30) and 1h (IG60) and one control group (CG). Flexibility was measured in bended and extended knee joint. Stretching was performed with a calf muscle stretching orthosis to ensure long-lasting stretching training. Data were analysed with a two-way ANOVA for repeated measures on two variables. Two-way ANOVA showed significant effects for time (ƞ² = 0.557-0.72, p \u3c 0.001) and significant interaction effects for time x group (ƞ² = 0.39-0.47, p \u3c 0.001). Flexibility in the knee to wall stretch improved with 9.89-14.46% d = 0.97-1.49 and 6.07-16.39% with d = 0.38-1.27 when measured via the goniometer of the orthosis. All stretching times led to significant increases in flexibility in both tests. While there were no significant differences measured via the knee to wall stretch between the groups, the range of motion measurement via the goniometer of the orthosis showed significantly higher improvements in flexibility depending on stretching duration with the highest increase in both tests with 60 minutes of stretch per day

    Isometric points in lateral ankle ligament reconstruction: A three-dimensional kinematic study

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    BACKGROUND To optimize the biomechanical outcomes in lateral ankle ligament reconstruction, avoid stiffness or residual laxity, aiming for an isometric reconstruction of the anterior lateral talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) is mandatory. However, the localization of the optimal ligament insertion remains challenging to assess intraoperatively. METHOD Three-dimensional (3D) surface models from 10 healthy ankles were generated. 30 insertion points of the CFL were defined on the lateral side of the calcaneus each 10% of its total length in the dorsal-to-ventral and proximal-to-distal plane. 6 insertion points were defined at the ventral ridge of fibula from the malleolar tip and 5 insertions were defined along the lateral talar process. The ligament length variation of ATFL and CFL was assessed after a simulation of the flexion/extension around a simulated tibiotalar axis and inversion/eversion around a simulated subtalar axis in 36 different positions. RESULTS The isometric point of CFL on the calcaneus is located at about 60% along the dorsal-to-ventral and between 60% and 70% along the proximal-to-distal plane. From maximal extension to flexion, these points present respectively a length variation of - 0.8 to - 1.1 mm (p = 0.46) and - 1.1 to - 0.8 mm (p = 0.56). A fibular insertion at 5 mm proximal to the malleolar tip present a length variation ranging from - 0.1-1 mm (p < 0.001) for ATFL and from - 0.7-0.5 mm (p < 0.001) for CFL. A talar insertion point of the ATFL located 5 mm proximal to the subtalar joint present the lowest variation, ranging from - 1.1-0.7 mm (p < 0.001), however an insertion at 20- or 25-mm present isometry (+0.1 to +0.9 mm p = 0.1, and +0.4 to +0.4 mm p = 1 respectively) if the fibular insertion is located at 5 mm proximal to the malleolar tip. CONCLUSION This study provides anatomical references which are reproducible in daily practice. These insertion points allow to achieve a stable reconstruction while maintaining a tension-free mobilization of the ankle

    A Phase-field Approximation of the Perimeter under a Connectedness Constraint

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    We develop a phase-field approximation of the relaxation of the perimeter functional in the plane under a connectedness constraint based on the classical Modica-Mortola functional and a diffuse quantitative version of path-connectedness. We prove convergence of the approximating energies and present numerical results and applications to image segmentation

    Mitbestimmte Netzwerkbildung: der Fall eineraußergewöhnlichen Dienstleistungsunternehmung

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    "Mit der Unternehmungsvernetzung geht in der Regel ein grundlegender Wandel industrieller Beziehungen einher. In dieser Intensivfallstudie wird ein innovatives Modell der Mitbestimmung im Unternehmungsnetzwerk porträtiert, mit dem die Risiken der Vernetzung für die Interessenvertretung und die Beschäftigten zum Teil aufgehoben werden. Dieses Modell, bei dem arbeits- und sozialpolitische Standards über die fokale Unternehmung in das Unternehmungsnetzwerk 'exportiert' werden, um zugleich den Interessen der Beschäftigten und den markt- und produktionsökonomischen Erfordernissen zu entsprechen, wird als mitbestimmte Netzwerkbildung bezeichnet. Aus einer strukturationstheoretischen Perspektive wird nach den sozialen Praktiken der mitbestimmten Netzwerkbildung, ihren Problemen und nach der Übertragbarkeit auf andere Unternehmungen gefragt. Die empirischen Daten wurden im Rahmen eines Forschungsprojekts vor allem mittels 37 leitfadengestützter Interviews mit Managern, Betriebsräten und Gewerkschaftssekretären erhoben." (Autorenreferat)"The evolution of inter-firm networks can lead to a fundamental change in the industrial relations. In this case study we describe an innovative model of codetermination in an inter-firm network which can be described as codetermined inter-firm networking. It ensures that most of the risks of inter-firm networking for employees, works councils and trade unions are avoided because labour standards of the core firm are 'exported' into the network to meet the interests of the workers and to fulfill the economic requirements. We investigate the characteristics of this new industrial relations practice and its problems. Furthermore we want to know if it provides a model for other firms. The empirical data were gathered as part of a broader research project mostly by 37 semi-structured interviews with managers, works council members and trade union officials." (author's abstract
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