In recent years, researchers focused their attention on biogas production more than ever to meet the energy demand. Especially, biogas obtained from algal wastes has become a trending research area owing to the high content of volatile solids in algae. The main purpose of this study is to determine the biogas production potential from algal wastes and examine the effect of temperature and particle size parameters on biogas yield. A comparison was made between the biogas production potential of microalgal wastes, obtained after oil extraction, and macroalgal wastes collected from coastal areas. It was found that algal biogas yield is directly proportional to temperature and inversely proportional to particle size. Optimal conditions for biogas production from algal wastes were determined as the temperature of 55 °C, a particle size of 200 μm, a residence time of 30 days and an alga–inoculum ratio of 1:4 (w:w). Highest biogas yield obtained under these conditions was found as 342.59 cm³ CH₄ g⁻¹ VS with Ulva lactuca. Under thermophilic conditions, both micro- and macroalgal biogas yields were comparable. It can be concluded that algal biomass is a good source for biogas production, although further research is needed to increase biogas yield and quality.

Today, there is an increasing concern and effort for protection, conservation, and restoration of cultural heritage materials. Non-invasive analytical methodologies such as Raman spectroscopy offers various advantages such as high speed, robust identification, low cost, and in-site analysis. Previous contributions highlighted the potential of Raman spectroscopy combined with multivariate statistics for identification and quality evaluation of cultural heritage materials such as paints, fiber, dyes, woods, stones, inks, and textile materials. Especially, application of chemometrics and multivariate statistics algorithms opens new horizons for scientists and inspectors. In conclusion, the paper provided an overview of the state-of-the-art uses of multivariate statistically equipped Raman spectroscopy methods for evaluation of cultural heritage and art materials with illustrations from previous research studies.