An actinometric method to characterize performance of reflecting UVC reactors used for water treatment.

The applicability of chemical actinometry to characterize the fluence in UV reactors with reflections, non-parallel light, and variable water transmittance is limited due to the unknown effective path length or hydraulic shortcuts within the reactor. In this study, the effects of reflection and transmittance on actinometry were examined and a new, optimized and easy method for determining fluence was developed. KI/KIO and uridine actinometry experiments were carried out under controlled conditions using a collimated beam apparatus and a completely mixed batch reactor with or without diffuse reflection and compared to biodosimetry results.

Application of a population balance model to a perfusion in vitro toxicity system.

Perfusion cell culture is different to static cell culture: In perfusion culture, steady state concentrations of nutrients and metabolites can be achieved. When a toxin is added to the medium, it is administered to the cells at a defined constant concentration. Perfusion culture is favourable for time series analysis of experimental data because assays can be performed online in the outflowing medium at a high time resolution.

Determination of silicon in urine by inductive coupled plasma-optical emission spectroscopy.

We describe an inductive coupled plasma-optical emission spectroscopic method to determine silicon in spot urine specimens. A 6-fold standard addition series of the urine specimen ranging from 0 to 356 micromol/l silicon was applied, and the method meets the requirement of matrix compensation in a frequently changing environment. The inter-assay variation was +/-3.