Improvement of Solar Cell Performance After Oxygen Removal by Electron Beam Melting

Two 450 kg multicrystalline silicon ingots were obtained by mixing and melting high purity silicon and silicon from the edges and the bottom of the casted ingots together in a casting furnace. For one of the ingot, the silicon from casted ingots was refined in an electron beam melting furnace to remove oxygen. The oxygen content was reduced from 10 to less than 0.0517 ppmw when silicon was refined at 500 kW with removal efficiency up to 99.429% in the most areas. The life time of the ingot after oxygen removal was measured to be far better than another one, whereas in the central parts the value was almost 6.7 µs. The efficiencies of both solar cells were initially 17.55% but after 4 h decreased to 17.05% and 15.55%, respectively. The solar cell after oxygen removal shows a better performance in degradation.     

Eco-friendly natural rubber–silver (NR–Ag) composites for photo-assisted degradation of methyl orange dye

An environmental friendly, low cost composite for the photo-assisted degradation of methyl orange (MO) is proposed. Here, natural rubber–silver (NR–Ag) composites are formed through soft thermal reduction. The characteristics of the NR–Ag composites were investigated using UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The deposition of Ag on the surface of natural rubber was proven by the XRD diffraction peaks, attributed to metallic Ag and the appearance of the surface plasmon resonance of Ag, at ~ 420–460 nm in the UV–vis spectrum. The degradation of MO dye by NR–Ag composite under UV light source showed positive results for the degradation of dye even with minute amounts of Ag content. The degradation mechanism of MO involved the generation of hydroxyl radicals from the UV-irradiated NR–Ag composite by the formation of superoxide species as the important radical intermediate. Several parameters such as the Ag salt concentration and pH of the MO dye were investigated. Complete degradation of MO was achieved when the composites containing 2 × 10^?3 wt% of Ag (NR–Ag₄) were employed at pH 3. Under this condition, complete degradation occurred within 30 min. Kinetic studies were conducted to understand the degradation phenomenon.     

Effect of Ozone on Fruit Quality and Fungicide Residue Degradation in Apples during Cold Storage

ABSTRACT

The potential of the ozone-enriched atmosphere for the improvement of the shelf life of apples of Gloster variety (Malus domestica) in cold storage was investigated. The storage experiment was conducted for 84 days. During that period, ozone at the concentration of 1 ppm was dosed every 12 hours for 1 minute. However, the exposure to ozone at such a concentration was unsuccessful in terms of inhibition of fungal disease development. Furthermore, the captan level in apples was reduced; therefore, they were more susceptible to fungal disease. On the other hand, the tests of the physical properties showed that utilization of ozone slowed down the ripening of apples; therefore, extending their shelf life provided that they were not infected.