Publications by authors named "Th van den Berg"

Objectives: To assess the efficacy and safety of Bispectral Index (BIS) guided Target Controlled Infusion (TCI) of midazolam for anxiolysis or minimal sedation during extensive periodontal or implant surgery in a single operator/sedationist model.

Methods: Retrospective analysis of thirty adult ASA 1 or ASA 2 patients undergoing periodontal surgery or dental implant surgery under local anaesthesia were included. The calculated effect site concentration (Ce) of midazolam applied by TCI, BIS, heart rate (HR), and peripheral oxygen saturation (SpO2) were monitored continuously.

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In the December 2014 issue of the Nederlands Tijdschrift voor Tandheelkunde, T.H. van den Berg and B.

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Approximately 800,000 Dutch people refrain from going to the dentist because of fear. Behavioural therapy, a psychological approach to treating anxiety, is taught extensively at the various Dutch universities and is used in dental practice in the Netherlands. For medicinal treatment, dentists in the Netherlands use nitrous oxide sedation and orally administered benzodiazepines.

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In turbulent Taylor-Couette flow, the injection of bubbles reduces the overall drag. On the other hand, rough walls enhance the overall drag. In this work, we inject bubbles into turbulent Taylor-Couette flow with rough walls (with a Reynolds number up to 4 x 10(5), finding an enhancement of the dimensionless drag as compared to the case without bubbles.

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In Taylor-Couette flow the total energy dissipation rate and therefore the drag can be determined by measuring the torque on the system. We do so for Reynolds numbers between Re=7 x 10(4) and Re=10(6) after having injected (i) small bubbles (R=1 mm) up to a volume concentration of alpha=5% and (ii) buoyant particles (rhop/rhol=0.14) of comparable volume concentration.

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We examine the torque required to drive the smooth or rough cylinders in turbulent Taylor-Couette flow. With rough inner and outer walls the scaling of the dimensionless torque G is found to be consistent with pure Kolmogorov scaling G approximately Re2. The results are interpreted within the Grossmann-Lohse theory for the relative role of the energy dissipation rates in the boundary layers and in the bulk; as the boundary layers are destroyed through the wall roughness, the torque scaling is due only to the bulk contribution.

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