A review of integrated phase change materials for evacuated tube solar collector system

This study presents a short review of research outcomes of low and medium temperature solid-liquid Phase Change Materials (PCMs) that are used for latent heat storage. The aim is to determine the appropriate materials for integration with the Evacuated Tube Solar Collector system (ETSC) in order to stabilize the intermittent temperature fluctuations and extend the operating hours. The study provides an insight into recent efforts to integrate PCMs with solar thermal systems, focusing on providing solutions to three of the disadvantages of PCMs, namely thermal stability, thermal conductivity and supercooling. The study uses the ‘Papadimitratos’ approach of integrating PCMs into the ETSC to provide an acceptable degree of validation in the selection of materials

Assessment and Management of the Water Quality and Heavy-Metal Pollution of a Protected Hypersaline Wetland in the United Arab Emirates

A hypersaline protected wetland in the UAE was assessed from February to April of 2021 for parameters such as temperature, pH, COD, total dissolved solids, ORP, electrical conductivity, total and E. coli, salinity, turbidity, chloride, ammonia, nitrate, total nitrogen, phosphorus, and heavy metals to assess its current status. Wasit Nature Reserve’s salinity values ranged between 17.1 and 64.78 psu, while D.O values ranged between 6.3 and 8.41 ppm. The values for nitrate were between 50.70 and 57.6 ppm, while the values for chloride were between 12,642.0 and 37,244.0 ppm. Results for heavy metals showed that Iron and Aluminum were the highest concentrations in sediments, with an average of 5599.3 mg/kg and 3171.1 mg/kg, respectively. Mercury and arsenic reported the lowest concentrations, with an average of 0.0 mg/kg and 2.4 mg/kg, respectively. Hazard quotient values were 2239.72 mg/kg for iron, 0 mg/kg for mercury, and 0.05 mg/kg for arsenic, indicating that iron levels are considered hazardous and water-quality indicators concluded high pollution levels. The results indicate that the hypersaline nature of the wetland contributes to the deviation from the permissible limits, as demonstrated by the calculated “poor“water-quality index and “highly polluted” water-pollution index. Due to their ecological relevance, wetlands in the region could serve as indicators of ecological well-being, highlighting the need for regular monitoring and evaluation