Aksaray University Journal of Science and Engineering
EISSN : 2587-1277
Current Publisher: Aksaray University Journal of Science and Engineering (10.29002)
Total articles ≅ 55
Latest articles in this journal
Published: 25 May 2021
Aksaray University Journal of Science and Engineering; doi:10.29002/asujse.911507
In this paper, a multi-band RF energy harvesting circuit is designed. The output voltage and power of the system built at 900 MHz, 1800 MHz and 2450 MHz frequencies are revealed. All simulations in this paper are made using the Advance Design System (ADS) 2017 program. The load resistances that give the maximum power for each frequency are determined and the appropriate load is selected for all three frequencies. Then, the multi-stage Dickson Voltage Multiplexer (DVM) from two to six stages is designed and the number of stages giving the maximum power for each frequency is determined using the selected load. L type and π type impedance matching have been applied to obtain the maximum output power in DVM design, which includes this number of stages and has two Schottky diode models (HSMS-2852). Finally, these three circuits are combined and the efficiency of the resulting from matching type are analyzed.
Published: 3 April 2021
Aksaray University Journal of Science and Engineering, Volume 5, pp 8-19; doi:10.29002/asujse.892979
Direct Current (DC) motors are widely used in industrial systems due to their high torque. In ensuring the stability and productivity of a system, it is important that the DC motor within the automation system reaches the reference speed value quickly and its speed remains constant under load. In this study, it is aimed to keep the speed value of DC motor constant under load by optimizing the gain parameters of the Proportional, Integral and Derivative (PID) controller, which is widely used in industrial applications. In the optimization of these parameters, the Ziegler Nichols method (ZNM) and the Ant Colony Optimization method (ACO) were examined comparatively in the simulation environment. PID parameters were determined by open loop responses under the running system with the ZNM. On the other hand, the most optimum solution was obtained among many parameters with the ACO method. Speed control of DC motor was performed with PID controller parameters which are determined according to the best ACO response. Simulation results are presented in comparison with the parameters of settling time, peak time, rising time and response of the system under load. As a result, PID controller run with Kp, Ki, and Kd parameters obtained by ACO algorithm generally gave better results than ZNM.
Published: 25 March 2021
Aksaray University Journal of Science and Engineering; doi:10.29002/asujse.749536
The aim of this paper is to assess and develop path loss propagation model for terrestial radio broadcasting station in Ikire, Nigeria. In carrying out the study, the reception quality of Osun State Corporation (OSBC) broadcast signal strength within Ikire metropolis in Irewole Local Government Area of Osun State, Nigeria was assessed using BC1173 Field Strength meter. The data obtained from the signal strength measurements around the metropolis were subsequently analysed and used for the development of an ideal propagation path loss model for the metropolis. The developed path loss model for the metropolis was evaluated and found to outperform the COST-231 Hata model in literature. The comparative performance evaluation result of the developed model and the COST-231 Hata model buttresses the need for developing different path loss models for different radio signals in different locations under different environmental factors. In addition, the finding of the study establishes a standard propagation path model that can be used for planning and designing efficient wireless communication link for terrestrial radio broadcasting station in the metropolis and any other environments with similar environmental factors.
Published: 2 February 2021
Aksaray University Journal of Science and Engineering; doi:10.29002/asujse.737686
The purpose of this work is to investigate and quantify x-ray fluorescence, its production and its spectroscopy. Characteristic x-ray with different energies were obtained from six various elements using Am-241 source with 59.5 keV. It was found that x-ray energy and intensity increase with increasing atomic number of material. X-ray spectroscopy was studied for such elements in respect to their atomic number and intensity of Kα characteristic x-ray using proportional counter. Furthermore, x-ray fluorescence was produced from different thickness of copper foil using different energies. It was found that there is no substantial different in x-ray fluorescence yield with higher thickness of the target.
Published: 30 December 2020
Aksaray University Journal of Science and Engineering, Volume 4, pp 187-198; doi:10.29002/asujse.820599
Published: 30 December 2020
Aksaray University Journal of Science and Engineering, Volume 4, pp 172-186; doi:10.29002/asujse.765097
Published: 30 December 2020
Aksaray University Journal of Science and Engineering; doi:10.29002/asujse.767122
Published: 28 December 2020
Aksaray University Journal of Science and Engineering; doi:10.29002/asujse.808557
Published: 24 December 2020
Aksaray University Journal of Science and Engineering, Volume 4, pp 113-126; doi:10.29002/asujse.688279
Published: 30 June 2020
Aksaray University Journal of Science and Engineering, Volume 4, pp 19-29; doi:10.29002/asujse.653362
In this study, the failures in Transformer Centers in Mersin Province Erdemli District have been investigated. The causes of the failures have been discussed. It is aimed to create a method for the reasons of possible failures of power transformer. The data have been collected by investigating the faults occurring at the Erdemli Substations. The failure statistics of the 200 power transformer failures that occurred between 2003 and 2019 in the Erdemli district of Mersin province have been examined. Examples of different power transformer failures have been given in fault analysis. The reasons of power transformer failures and the precautions to be taken have been explained.