Comparison of tiletamine-zolazepam and tiletamine-zolazepam-ketamine-xylazine administered intravenously in dogs

The anaesthetic effects of intravenous administration oftiletamine (2.5 mg/kg) - zolazepam (2.5 mg/kg) mixture (TZ), and tiletamine (0.5 mglkg) - zolazepam (0.5 mg/kg) - ketamine (1.6 mg/kg) - xylazine (0.4 mg/kg) mixture (TKX) were evaluated in ten dogs. Atropine sulphate at a dose rate ofO.05 mg/kg was administered concurrently with the anaesthetic mixtures. Both mixtures produced rapid, smooth induction, and allowed intubation. The TKX mixture produced longer skin clamp analgesia and immobilisation, better jaw relaxation, with shorter and smoother recovery compared to TZ injection. The TKX mixture induced significant but transient pallor of mucous membranes « 2 min). The TZ mixture resulted in increased heart rate and a higher respiratory rate compared to TKX mixture. Haemoglobin saturation was < 90% in some dogs following either mixture. The TKX mixture can be considered as an alternative injectable mixture to TZ for short and minimally invasive procedures in patients that have no cardiopulmonary dysfunction

On the modelling of population balance in isothermal vertical bubbly flows - average bubble number density approach

To model the spatial evolution of the geometrical structure of the gas bubbles in isothermal vertical bubbly flow conditions, the population balance approach has been employed and merged with the three-dimensional two-fluid model. The population balance is realized by incorporating an average bubble number density transport equation into a commercial computational fluid dynamics (CFD)codeANSYS CFX 10. The coalescence and breakage effects of the gas bubbles are formulated according to the bubble coalescence by random collision driven by turbulence and wake entrainment while for bubble breakage by the impact of turbulent eddies. Three models representing these coalescence and breakage mechanisms proposed by Wu et al. [1], Hibiki and Ishii [2] and Yao and Morel [3] are assessed. Local radial distributions of the five primitive variables in bubbly flows: void fraction, Sauter mean diameter, interfacial area concentration, and gas and liquid velocities, are compared with two experimental data of Liu and Bankoff [4,5] and Hibiki et al. [6]. Close agreements between the predictions and measurements demonstrated the capability of the average bubble number density transport equation in modelling bubbly flow conditions