Effects of infrared power output and sample mass on drying behaviour, colour parameters, ascorbic acid degradation, rehydration characteristics and some sensory scores of spinach leaves were investigated. Within both of the range of the infrared power outputs, 300–500 W, and sample amounts, 15–60 g, moisture content of the leaves was reduced from 6.0 to 0.1±(0.01) kg water/kg dry base value. It was recorded that drying times of the spinach leaves varied between 3.5–10 min for constant sample amount, and 4–16.5 min for constant power output. Experimental drying data obtained were successfully investigated by using artificial neural network methodology. Some changes were recorded in the quality parameters of the dried leaves, and acceptable sensory scores for the dried leaves were observed in all of the experimental conditions.

GZO/IZO semiconductor thin films were prepared on the ITO substrate via sol-gel spin coating method for using in the dyesensitized solar cells (DSSCs). For this purpose, GZO and IZO thin films were optimized by the percentage of doping gallium and indium in zinc oxide and were studied their electrical, optical and structural properties. After that, the layers with the best performance were selected for use in the DSSCs. The concentration of all solutions for spin coating processes was 0.1 M and zinc oxide has been doped with gallium and indium, with different doping percentages (0, 0.5, 1, 2 and 4 volume percentage). So, by studying the properties of the fabricated thin films, it was found the films with 0.5%GZO and 0.5%IZO have the best performance and hence, the optimized dual-layer (0.5% GZO/0.5% IZO (GIZO)) were prepared and studied their electrical and optical properties. The synthesized optimized dual-layer film was successfully used as the working electrode for dye-sensitized solar cells. The sample with 0.5%IZO shows the 9.1 mA/cm2 short-circuit current density, 0.52 V open circuit voltage, 63% fill factor and 2.98% efficiency.

The research aimed to find suitable solutions to reduce the salinity stress of irrigation water for some types of vegetables in hydroponics under two drip and mist irrigation systems. The different concentrations of NaCl for irrigation water, are 500, 1000, 2000, 3000, and 4000 ppm used. Proline (30 mg∙dm ^–3), humic acid (300 mg∙dm ^–3) and compared without any from them were used to study their effect on the yield, and water use efficiency. The results indicated that the highest spinach and courgette yield (4.657 and 5.153 kg∙m ^–2) was observed for the DP500 treatment, and the lowest yield (0.348 and 0.634 kg∙m ^–2) was observed for the SW4000 treatment, respectively. The use of humic acid led to an increased yield on average by about 16.8 and 19.3% for spinach, and 39.4 and 51.7% for courgette, under drip and mist irrigation, respectively. Using proline led to an increased average yield of about 32.9 and 33% for spinach, and 51.8 and 58.4% for courgette, under drip and mist irrigation, respectively. The highest water use efficiency (WUE) of spinach and courgette (43.1 and 51.5 kg∙m ^–3) was observed for the DP500 treatment, and the lowest (3.2 and 6.3 kg∙m ^–3) was observed for the SW4000 treatment. According to our study, the use of proline and humic acid could compensate for the adverse effects of salinity under mist spraying more than drip irrigation.

Owing to its high concentrations of nitrogen and phosphorus, the slurry from water hyacinth (Pontederia crassipes) biogas production cannot be discharged directly without further treatment. To achieve the target of water recycling, a new strategy of combining a Carrousel oxidation ditch with a water spinach wetland was developed in this study for the harmless treatment of Pontederia crassipes biogas slurry. First, the water quality characteristics of the biogas slurry were measured. Then, comprehensive tests of the combined slurry treatment system were carried out to verify pollutant removal performance and mechanism. The results showed that the Carrousel oxidation ditch reduced the inlet pollutant load of the subsequent water spinach wetland. The chemical oxygen demand (COD), and ammonium nitrogen (NH4+-N), total nitrogen (TN), and total phosphorus (TP) contents of the average effluent from the combined system were less than 50 mg/L, 1.6 mg/L, 6 mg/L, and 0.5 mg/L, respectively, which means that all met urban sewage treatment standard of Level 1 Grade A (GB18918-2002). Gas chromatography – mass spectrometry analysis showed that the combined system had decreased various types of organic pollutants in the biogas slurry exponentially, efficiently removing alkane pollutants, aromatic hydrocarbons, and heterocyclic compounds. Scanning electron microscopy images revealed very large surface area of the water spinach roots in the wetland, which played important roles in enriching the microorganisms and trapping organic matter. Plant absorption, microbial degradation, and filtration were the primary ways in which the water spinach wetland purified the biogas slurry.