NTU Journal of Renewable Energy

Present paper is performed to production of biodiesel fuel BDF from castor oil CO. The effect of the molar ratio of alcohol to oil, temperature, and the type of catalyst factor on the efficiency of BDF production was studied. Esterification reactions were used to convert fat into fuel. The ideal molar ratio of methanol to oil is 1:7. The reaction temperature is 65°C, and the reaction time is 120 minutes. The concentration of the catalyst was 1% by weight of the CO. The conversion efficiency is 97% when using the above amounts. Potassium hydroxide is better than sodium hydroxide in esterification reactions. The physical specifications of the produced fuel are in accordance with the international specifications of ASTM, except for a tiny increase in viscosity. But it is within the permissible range. After completing the reaction process, the separation took two hours, unlike traditional techniques that take five days.

A sample of the bread yeast Saccharomyces cerevisiae strain was taken from the local markets in the city of Mosul and grown on the appropriate medium for it in order to test its ability to remove some heavy metals. Concentrations for each metal ph and three temperatures The grown bread yeast was able to remove both zinc and lead alone and remove them both. The highest removal of zinc was 1.99 ppm , and lead was 0.5 ppm. It was noted that the removal rate increased according to the two minerals together, as the temperature was 10 and 25 The best value for pH is 4 and 9

The objective of this paper is to study the performance of TPC. A theoretical study was conducted to examine the Effect of mass flow on PTC performance. It was done at the Renewable Energy Unit in Hawija, Iraq. Use water as working fluid WF at a mass flow rate of 0.00083.0.0011 0.00138, and 0.00166 Kg/s. The concentration ratio of 10, 14, 18 and 22 are used. This theoretical investigation was carried out by ASHRAE 93-1986 (RA-91). The results indicate that the theoretical efficiency starts at 40% in summer and increases relatively as mass flow increases to a maximum value of 6% in Winter. Moreover, the results demonstrated that efficiency is inversely related to concentration ratio and temperature. The performances of TPC in spring and autumn are convergent.

One of the most important technical aspects to consider during the technical study and practical installation of the solar panels is choosing the location of the solar panels, Because it's probable that some of its cells will be shaded. PV characteristics become more complex under partial shade situations, with several peaks.Partial shading affects the performance of the solar cell in proportion to the state of shadow; this negative performance will be reflected on the current generated by the solar cell; of the current value of the other cells (being connected in series) which will decrease the overall performance of the solar panel. The goal of this study is to demonstrate the impacts of partial shade on a PV array by analyzing various shading situations.First, this is done using Matlab/Simulink.

A Theoretical and practical study was conducted to analyze the performance of a closed type parabolic trough collector CTPTC. The study was conducted in northern Iraq at longitude 43o.53 and latitude 35º.25. Use water as a working fluid at a mass flow rate of 0.00083,0.0011 0.00138, 0.00166, Kg/sec, with a concentration ratio of 10, 14 and 22. The maximum value of experimental efficiency of 42% in the summer and 29% in the Winter. The theoretical study was conducted according to ASHRAE 93-1986 (RA-91). The hypothetical results show that theoretical efficiency starts at 30% and increases relatively with increasing mass flow and decreases with temperature and the concentration ratio to reach a maximum value of 50%in the summer and a maximum value of 68% in the Winter.

Since the calculation of the active and reactive power is considered an essential topic nowadays, the novel method is focused on these calculations with omitting the PLL that will decrease the complexity of the control process. To get the maximum photovoltaic (PV) output, the maximum power point tracker (MPPT) algorithm has been integrated with the proposed method. MATLAB/SIMULINK has been used to show the performance of the proposed method. The simulation outcomes verify the advantage of the novel method by improving the total harmonic distortion (THD) and the system stability regardless of load changes.

A numerical study was achieved on a new design of storage solar collector by using neural network (NN). The storage collector is a triangular face and a right triangular pyramid for the volumetric shape. It is obtained by cutting a cube from one upper corner at 45o, down to the opposite hypotenuse of the base of the cube. The numerical study was carried out using the computational fluid dynamics code (ANSYS-Fluent) software with natural convection phenomenon in the pyramid enclosure. The results show that, the temperature and velocity distributions throughout the operating period were obtained. The influence of introducing an internal partition inside the triangular storage collector was investigated. Also the optimum geometry and location for this partition were obtained. The enhancement was best at y= 0.25 m whereas the height of triangular collector was 0.5 m. The hourly system performance was evaluated for all test conditions. The performance of the NN to train a model for this work was 0.000207, while the error of the calculation was 1*10^-2 as average.

Detailed numerical modeling and research were conducted to assess the influence of wind loads on various solar arrays using commercial software such as Ansys. A large amount of damage has been recorded from solar arrays and mounting frames worldwide owing to strong winds. This paper exemplifies the analysis of displacement and stresses of the structure due to strong wind flow and wind load around the solar panel. Since the solar panels are located in the same panel array at the same spacing, we assume that periodic flow conditions can be applied in the flow direction. The model displays a flow field with a free flow velocity of 10 m/s , 25 m/s, and 50 m/s and calculates the resulting structural stresses and displacements. This model uses two other studies. Initially, Turbulent Flow, a k? physical interface, is used to resolve turbulence around the solar panel. The other uses the Solid Structure physical interface to resolve structural stresses and displacements. Fluid Structure Interaction, Fixed Geometry Multiple physical coupling features are used to connect the boundary load of a fluid flow to a solid region in the fluid region. It corresponds to unidirectional fluid structure interaction analysis.