For a study about the effect of UV and temperature on plastic degradation and to compare the changes between different UV and temperature levels by using fresh plastic pellets. What would be the temperature and UV ranges which I need to use. Is it ok to use temperatures between 30 and 80, and if such what should be the difference of degrees between two temperatures? As well as what should be the most desired UV range I need to use? Your recommendations will be a grater help to me.