Search results for "3d simulation"
showing 4 items of 4 documents
Virtuelle 3-D-Laparoskopie-Simulation in der chirurgischen Aus- und Weiterbildung – Ergebnisse einer Pilotstudie
2013
Hintergrund: Dem technischen Fortschritt folgend, werden im Operationssaal Module zur 3-dimensionalen Darstellung in der Laparoskopie eingesetzt. Erste Untersuchungen an Box-Trainern haben diskrepante Ergebnisse gezeigt. Fur die Virtual-Reality-Laparoskopie (VRL) fehlen Daten zur 3-dimensionalen Simulation. Material und Methoden: 5 Facharzte fur Chirurgie, 10 chirurgisch tatige Arzte in Weiterbildung und 29 Medizinstudenten fuhrten abstrakte und prozedurale Ubungen am VRL-Simulator im 2-D- und 3-D-Modus durch. Die Reihenfolge der Durchfuhrung (2-D/3-D) wurde randomisiert. Ergebnisse: Fur Arzte und Studenten zeigten sich keine signifikanten Leistungsunterschiede fur Ubungen im 2-D- und 3-D-D…
EXTERNAL RECIRCULATION IN PRS TYPE TURBINE: EXPERIMENTAL AND NUMERICAL RESULTS.
2022
Cavitation is a relevant phenomenon for structural safety and noise level in hydraulic turbines, occurring when water pressure falls below the vapor value at a given temperature. In this case bubbles of vapor grow inside the liquid and move along with it. When the pressure returns above the vapor value the bubble collapses, and the pressure can locally achieve very high values, up to 7000 bars (Kumar & Saini, 2010). Moreover, if the bubble was confined also by the solid wall of a blade, the solid particles suspended in the fluid can be transported by the fluid ones and hit the solid wall at very high velocity, generating erosion. Cavitation is also the source of high frequency noise, ve…
A Comprehensive Model for Hydraulic Analysis and Wetting Patterns Simulation under Subsurface Drip Laterals
2022
In the absence of suitable specialized models to simulate the soil wetting patterns in subsurface drip irrigation systems considering the hydraulic conditions along the laterals, a new model was developed and named a “comprehensive model” in this study. This model couples the subsurface drip irrigation lateral characteristics with the soil hydraulic properties and utilizes the Hydrus-3D software as a complementary section of the model to simulate the wetting front beneath the lateral. To evaluate the model, three 16 mm drip-line pipes of 62 m length with 20, 40, and 50 cm spacing emitters and 2 to 5 L/h discharge were buried at 0.2 m depth in a soil box containing clay loamy soil. Then, the…
Atrial Fibrosis Hampers Non-invasive Localization of Atrial Ectopic Foci From Multi-Electrode Signals: A 3D Simulation Study
2018
[EN] Introduction: Focal atrial tachycardia is commonly treated by radio frequency ablation with an acceptable long-term success. Although the location of ectopic foci tends to appear in specific hot-spots, they can be located virtually in any atrial region. Multi-electrode surface ECG systems allow acquiring dense body surface potential maps (BSPM) for non-invasive therapy planning of cardiac arrhythmia. However, the activation of the atria could be affected by fibrosis and therefore biomarkers based on BSPM need to take these effects into account. We aim to analyze the effect of fibrosis on a BSPM derived index, and its potential application to predict the location of ectopic foci in the …