Search results for "Actinometer"
showing 3 items of 3 documents
An experimental method for the determination of the photon flow reflected and absorbed by aqueous dispersions containing polycrystalline solids in he…
1991
An experimental method for the evaluation of the photon flow reflected and absorbed by aqueous dispersions containing polycrystalline solids is proposed. The method is based on actinometric measurements. It is shown that the values obtained are independent of the particle sizes and of the concentration of the solids at least in the experimental conditions and in the range used in the present study (particle size range: 40–500 μm; solids concentration: 0.1–2 g liter−1). The results suggest that the values obtained should be attributed to the interfaces formed between the surface of the solids and the medium. The method is applied to a photocatalytic reaction, namely to the photodegradation o…
Actinic Radiation and Photolysis Processes in the Lower Troposphere: Effect of Clouds and Aerosols
2002
Within the German Tropospheric Research Program (TFS) a series of projects were performed focussing on aspects of radiation transfer and the effects of UV-radiation on air chemistry. The individual projects covered laboratory investigations, instrument development for photolysis processes as well as field studies of actinic radiation and comparison to model calculations. One and three-dimensional models were tested against field campaign data. The results confirm the improvement of measurement technology achieved through deployment of new techniques like spectroradiometry that offer a wider range of investigations than was previously attainable using chemical actinometry or fixed wavelength…
Photon absorption by aqueous TiO2 dispersion contained in a stirred photoreactor
1991
We present a simple experimental method which allows the evaluation of the absorbed photon flow. The method is based on measurements of transmitted photon rates (by means of standard actinometer solutions) for different reactor thicknesses and/or catalyst concentrations. The method was applied to phenol degradation reaction carried out in a stirred batch phtotoreactor containing aqueous TiO 2 (anatase) dispersion, directly irradied by a 1,500 W Xe lamp