الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The study aimed to utilize solar energy as an only source for heating and distilling seawater and obtaining the fresh water for drinking, agricultural and industrial purposes by Designing and fabricating three identical passive single-slope solar stills covering with 2.0 mm thick acrylic plate and sloping angle 35˚. Study the effects of engineering and environmental factor on the thermal performance efficiency, and the productivity rate of freshwater of these solar stills, also Investigate the influences of using solid-sized nanoparticles (Nano-fluid) on the thermal performance efficiency and the productivity rate of freshwater and estimate costs of distilled one litre of freshwater. The study included three experiments, first experiment included Study the effects of three different depths of saline water in the basin (1, 2, and 3 cm) on the thermal performance efficiency and the daily average productivity rate of freshwater during the period from the 1st of January 2020 until the 19th of April 2020. The second experiment was executed to modify the single-slope solar still using copper oxide (CuO) as solid-sized nanoparticles with weight concentration of 0.028% that precisely mixed with 7.2 litres of seawater in the still basin and another solar without Nano with 7.2 litres seawater during the period from the 23rd of April 2020 until the end of 6th of June 2020. The third experiment was carried out to examine the effect of increasing the weight concentration into 0.042% on the thermal performance, distillation efficiency, and the productivity rate of freshwater during the period from the 7th of June 2020 until the 6th of July 2020. The results of study concluded that The thermal efficiency for the smallest depth (1cm) of seawater was higher than that of the other two depths (2,3cm) by 22.44% and 49.03%, respectively. The smallest depth of seawater augmented the productivity rate of freshwater by 42.04% and 77.27% as compared with the other two depths, respectively. The estimated costs of distilled one litre of freshwater from the three different depths of water, respectively, were approximately 0.68, 0.96, and 1.20 EGP. As a result of using the solid-sized nanoparticles with weight concentration of 0.028%, the thermal performance efficiency and the productivity rate of freshwater of the solar still with nanoparticles was more than that of the other solar still by 12.44% and 52.70%. The calculated costs of distilled one litre of freshwater for the two solar stills with and without nanoparticles (0.028% weight concentration) were approximately 0.41 and 0.60 EGP/litre, respectively. Use the solid-sized nanoparticles with weight concentration of 0.042%, induced in increasing the hourly average thermal performance efficiency and the productivity rate of freshwater by 17.26% and 58.38% over the other solar still without nanoparticles. The estimated costs of distilled one litre of freshwater for the two solar stills with and without nanoparticles (0.042% of weight concentration), respectively, were approximately 0.38 and 0.57 EGP/litre. The study can recommend that, the depth of brine water in the solar still basin must be assessed according to the intensity of solar radiation available on the place in question. Mixing the brine water in the basin with solid-sized-nanoparticles can be changed the characteristics of heat transfer and the thermal properties within the solar still. As a result, the evaporation-condensation heat transfer can be augmented and consequence the rate of freshwater productivity increased.