ملخص البحث :

An execution a double slope of the solar still Integrated With or withoutparabolic trough collector is investigated experimentally. Several worksare undertaken to improve the output of solar still. Used wax as phasechange material (PCM) was an effective method of storing thermal energywith parabolic trough collector (PTC).It transferred incident solar energyto solar still through water tube connected with heat exchangerembedded in wax (PCM) in double slope of solar still, with testsconducted by maintaining the depth water in tank at 20 mm after fixingthe orientation. Through the study of the results, it was found that a solarstill using PTC has better productivity and temperature than withoutusing PTC, in addition to the possibility of using heat energy storagemediums in the DSSS for ensuring the continuity of production of waterafter sunset. Experimental results observe that effect of the PTC withPCM in the Double Slope of Solar Still increased the productivity of34.35% and 56.3% respectively.

ملخص البحث :

Iraq is located with very high solar irradiance and the enormous potential of solar energy can be tapped to convert saltwater to freshwater. The easy way and very economical to achieve this goal is to implement solar destination systems. The simulation modelling and performance analysis of a Tubular Solar Still (TSS) was present in this work. Two different types of phase change materials (PCMs) solid-liquid type have been used as a heat storage medium. A series of numerical simulations were performed to the prediction of heat transfer of the TSS. The thermal efficiency of the tubular solar still (TSS) was tested the performance during a day in a different weather condition (solar irradiance, ambient temperature and wind). the main numerical results refer to a better performance was obtained via TSS integrated with of PCM (2.664kg of paraffin wax or 3.143kg of stearic acid) compared to TSS without PCM. In general, the system containing paraffin wax was effective in the system with or without stearic acid. It appeared there was a good agreement obtained.

ملخص البحث :

Rising temperatures significantly affect the PV module, decreasing its voltage and lowering output power. Furthermore, temperature rises have been linked to several PV module failures or degradation modes. The purpose of this study analyzes polyvinyl alcohol PVA on crystalline silicon solar cells as a thermal insulation thin film. PVA thin films were prepared by dip-coating technique with a thickness of 1.15μm. The films exhibit suitable solar cell temperature controlling though it's an effect on masking the ultraviolet wavelength. The maximum temperature variation on the coating solar cell's surface was 4.5 °C as a comparison to a bare solar cell with irradiate exposure time 1800sec, and maximum efficiency obtained 18.99% in which Voc = 0.566 v and Isc = 330.2 mA when compared with bare solar cell 15.07% with benefit efficiency +3.92%. The concentrations of the polyvinyl alcohol influences on thin films and their effect on solar cell parameters are discussed.

ملخص البحث :

Solar distillation collectors are the device that runs on freshwater products. The solar still is one solar thermal technology for purification of water. This technique is employed to convert saline water into freshwater. At this time, the human being increased freshwater required consumption because of the increasing population density. The thermal analysis of a new design of cylindrical solar still (CSS) with hemispherical cover has been studied. A computer simulation model was improved to investigate its performance. The 2D symmetry simulation models of cylindrical solar still have been validated. The simulation model can emulate the temperature value of different points inside the CSS. The simulation results confirm an acceptable agreement with the experimental result was reported in the literature. From this simulation, it was noted that the freshwater product from the cylindrical solar still obtains the maximum daily productivity of 6.1 kg/m2 as compared to a traditional single slope solar still SSS as 3.18 kg/m2 during the day.

ملخص البحث :

An execution a double slope of the solar still Integrated With or without parabolic trough collector is investigated experimentally. Several works are undertaken to improve the output of solar still. Used wax as phase change material (PCM) was an effective method of storing thermal energy with parabolic trough collector (PTC).It transferred incident solar energy to solar still through water tube connected with heat exchanger embedded in wax (PCM) in double slope of solar still, with tests conducted by maintaining the depth water in tank at 20 mm after fixing the orientation. Through the study of the results, it was found that a solar still using PTC has better productivity and temperature than without using PTC, in addition to the possibility of using heat energy storage mediums in the DSSS for ensuring the continuity of production of water after sunset. Experimental results observe that effect of the PTC with PCM in the Double Slope of Solar Still increased the productivity of 34.35% and 56.3% respectively

ملخص البحث :

Iraq is located with very high solar irradiance and the enormous potential of solar energy can be tapped to convert saltwater to freshwater. The easy way and very economical to achieve this goal is to implement solar destination systems. The simulation modelling and performance analysis of a Tubular Solar Still (TSS) was present in this work. Two different types of phase change materials (PCMs) solid-liquid type have been used as a heat storage medium. A series of numerical simulations were performed to the prediction of heat transfer of the TSS. The thermal efficiency of the tubular solar still (TSS) was tested the performance during a day in a different weather condition (solar irradiance, ambient temperature and wind). the main numerical results refer to a better performance was obtained via TSS integrated with of PCM (2.664kg of paraffin wax or 3.143kg of stearic acid) compared to TSS without PCM. In general, the system containing paraffin wax was effective in the system with or without stearic acid. It appeared there was a good agreement obtained

ملخص البحث :

The performance of two solar still systems has been investigated experimentally by taking the effect of parabolic trough collector (PTC) and phase change material (PCM). The effect was investigated under different environmental conditions. The productivity of the solar still was the main factor that was considered as a criterion for comparison. One day was taken under the investigation; 22-December 2020. Results show that a solar still using PTC with PCM has better productivity and temperature than without using PTC, And the additive PTC unit with the PCM basin causes an increase in temperatures of the system, and also an increase in rate productivity by 0.72 % than the solar still system without PTC.

ملخص البحث :

Zinc oxide (ZnO), a direct bandgap semiconductor, provides tremendous promise in various applications, such as optical waveguides, clear conductive oxides, and chemical gas sensors. It is also used in UV-light emitters, piezoelectric transducers. ZnO is in various forms, such as nanoparticles, Nano-belts, Nano-rods, nano-tubes, and nanowires. The purpose of this research is to review a general overview of ZnO and its application, the use of ZnO as an anti-reflection coating with various styles on the solar cells, and the conventional and unconventional techniques that had been used to coating the anti-reflection layers on the solar cell will be reviewed. This is based on a review of previous studies related to applications of anti-reflective coatings of ZnO and make a comparison of practical results was obtained with different semiconductor materials (SIC, TiO2, ZnS, SiO2, SiN4).

ملخص البحث :

This study investigated the production of single slope solar still and the influence of combining with a parabolic trough collector. The effect of the different working fluid types on freshwater productivity, outlet working fluid temperature, heat gain, and thermal efficiency has been studied under the weather conditions of south city of Iraq/ Najaf (32° 1' N / 44° 1' E). The first type was water and the second type is nanofluid. The results of the comparison showed when using water as a working fluid flowing inside the receiving tube for different days; the highest temperatures were obtained at 12:00 pm, and the average productivity of distilled water was obtained in May and June 2021 were 4.5358 and 6.733 kg/m2/day respectively. While when using the nanofluid as a working fluid flowing inside the Parabolic Trough Collector (PTC) receiver tube, the outlet temperatures were rising for the same comparison days with an increase in the productivity of distilled water. Where the freshwater productivity during the day was 8.745328 kg /m2 /day as, and it was 9.018119 kg/m2/day during the other day. A productivity analysis was carried out for two different working fluid types (Water and nanofluid instead of water) as a fluid running inside the receiving tube of PTC. The freshwater produced from PTC (with nanofluid) was a 42.2% improvement in productivity compared with conventional PTC.

ملخص البحث :

Reflection loss and solar cell temperature both have a significant impact on solar cell efficiency and, consequently, on power generation. Herein, the aim is to investigate into the impact of Nanocomposite Titanium Dioxide (TiO2)/Polyvinyl Alcohol (PVA) on polycrystalline silicon solar cells. The solvent casting method is employed to prepare nanocomposite TiO2/PVA for deposition on the front side of the solar cell. The Tauc plot is used to investigate the influence of TiO2 nanoparticle concentration (10-20nm) on the energy bandgap of a nanocomposite. To test the optical properties of the solar cell after depositing the Nanocomposite coating film and to confirm the suspension of TiO2 in PVA and construct a Nanocomposite, an ultraviolet-visible spectrometer and a Fourier transform infrared spectrometer are provided. The results show that increasing the TiO2 in the TiO2/PVA Nanocomposite increases the energy bandgap. The Ultraviolet-Visible spectrometer observes that the Nanocomposite films absorb the Ultraviolet wavelength and transmittance at the visible wavelength. Finally, it found the lowest reflection obtained was 3.9% for 0.2wt% TiO2 in TiO2/PVA nanocomposite and the enhancement of the solar cell efficiency was (+2.3%).