Alp Alexander Rosemann

Recommendations for measuring non-image-forming effects of light: A practical method to apply on cognitive impaired and unaffected participants.

BACKGROUND The non-image-forming effects of luminous radiation on people with intellectual disabilities or dementia received attention from researchers. Such studies, however, have generally been conducted using disparate methodologies which precludes generalization and reproducibility. OBJECTIVE The aim of this study was to determine the practical applicability of measurement devices for studies investigating non-image-forming effects of luminous radiation, specifically for people with intellectual disabilities or dementia. METHODS In three experiments, ten cognitive impaired people and thirty-nine unaffected subjects participated by wearing one or more portable devices. Six devices were assessed in total. Measurement data was accompanied with user experiences obtained from questionnaires, interviews and observations in order to assess the devices on practical and comfort issues. RESULTS On average, the devices worn by the cognitive impaired subjects were not experienced as annoying or irritating. No significant differences are found between genders and for one of the portable devices significantly less annoyance was reported by the cognitive impaired participants compared to the unaffected group of participants. INNOVATIVE SOLUTION The three phases of the research process in towards measuring personal luminous exposures are: selection of the most suitable portable device, application of the assessment method, and the application of the device in the (pilot) study. CONCLUSIONS However, the findings of this study suggest that inaccuracies potentially caused by practical and comfort issues associated with the portable devices need to be considered.

A new design for luminescent solar concentrating PV roof tiles

In our paper we explore the opportunity of combining luminescent solar concentrating (LSC) materials and crystalline PV solar cells in a new design for a roof tile by design-driven research on the energy performance of various configurations of the LSC PV device and on the aesthetic appeal in a roof construction. We present the roof tile in a system and executed optical modeling of the solar roof tile by Monte-Carlo/ray-tracing simulations by PV trace. We determined the range of appropriate values for thickness and dye concentration for the conceptual design of roof tile LSCs. It can be concluded that thickness of PMMA sheet material could best be in the range of 4 to 6 mm and the concentration of BASF Lumogen Red dye in between 80 and 1000 ppm. Because of aesthetic considerations however various concentration values may be used. In follow-up activities include a.o. parameter studies for different BASF Lumogen dyes and a pilot setup for testing the prototypes outdoors in the Netherlands.