Aksaray University Journal of Science and Engineering
EISSN : 2587-1277
Published by: Aksaray University (10.29002)
Total articles ≅ 58
Latest articles in this journal
Published: 22 September 2021
Aksaray University Journal of Science and Engineering; https://doi.org/10.29002/asujse.992420
Fractional diferential equations (FDEs) have attracted the curiosity of many people and have been utilized to address a wide range of problems in science. Various type of techniques have been established to deal with FDEs and to get approximate or analytical solutions. In this study, residual power series method (RPSM), which determine the coefficients of the power series by using the idea of residual error, is used. Furthermore, the conformable derivative is proposed to characterize and define the fractional derivatives. Then, the definition and initial values of Drinfeld–Sokolov–Satsuma–Hirota (DSSH) equation is introduced, and approximate solution of this equation is acquired by using the RPS method. Mathematica computer programming language is used to get these approximate solutions and beneficial graphs with the different fractional operator. Lastly, the RPSM approximate solutions are compared to the exact solutions with the various tables and graphs. The findings indicate a significant degree of agreement between the approximate solution of RPSM technique and the exact solution of DSSH equation when comparing numerical solution with the exact solution. As a result, according to this study, the method introduced is simple to use and provides a considerable advance in this area compared to prior approaches. Kesirli diferansiyel denklemler (FDEs) bilim ve mühendislikteki çeşitli sorulara çözüm bulmak için son zamanlarda sıkça kullanılmaktadır ve böylece çok sayıda araştırmacının dikkatini üzerine çekmektedir. Kesirli diferansiyel denklemleri çözmek, onların yaklaşık ve analitik çözümleri bulmak için birçok teknik geliştirilmiştir. Bu makalede, rezidual kuvvet seri metodu (RKSM) olarak adlandırılan ve rezidual hata düşüncesinden yola çıkarak kuvvet serisinin katsayılarını belirleyen kolay uygulanabilir, kullanışlı ve etkili bir yöntem kullanılmıştır. Bununla birlikte, kesirli türevleri karakterize eden ve tanımlayan uyumlu(conformable) türev tanımı yapılmış ve denklemlere uygulanmıştır. Daha sonra ise Drinfeld–Sokolov–Satsuma–Hirota (DSSH) denkleminin tanımı yapılmış ve başlangıç değerleri tanıtılmıştır. Bu denklemin yaklaşık çözümü rezidual kuvvet seri metodu yardımıyla elde edilmiştir. Farklı operatör değerleri için, yaklaşık çözümleri ve faydalı grafikleri bulurken bir bilgisayar programlama dili olan Mathematica programı kullanılmıştır. Ayrıca, çalışmanın son bölümünde çok sayıda grafik ve tablo kullanılarak RKSM yöntemi sonucunda bulunan yaklaşık çözümler ile tam çözümler kıyaslanmıştır. Nümerik çözümler ile tam çözümlerin karşılaştırılmasıyla bulunan sonuçlar RKSM yönteminin yaklaşık çözümleri ile Drinfeld–Sokolov–Satsuma–Hirota (DSSH) denkleminin tam çözümü arasında çok önemli bir tutarlılık olduğuna işaret etmektedir. Sonuç olarak, bu çalışmaya dayanarak uygulanan metodun çok başarılı, etkili ve tutarlı olduğuyla, kullanım kolaylığı sağladığı ve daha önceki yapılmış çalışmalara kıyasla önemli bir ilerleme getirdiğini söyleyebiliriz.
Published: 8 July 2021
Aksaray University Journal of Science and Engineering, Volume 5, pp 65-77; https://doi.org/10.29002/asujse.866010
Following the continuous deterioration of flexible road pavements on Federal Highways in Northern Nigeria, which in some quarters is attributed to poor structural capacity of the subgrade soil or design and workmanship; this study examined the relationship between the instantaneous surface condition of flexible road pavement and the California Bearing Ratio (CBR) values of the corresponding subgrade soils. An investigation of road surface condition was carried out on 60 km length of the Zaria – Kaduna Federal Highway in Northern Nigeria. Experimental results on the mechanical properties of the corresponding subgrade soils of road segments measured at Chainages were obtained from the Nigeria Federal Ministry of Power, Works and Housing (FMPWH). The primary data used by the study were measured as quantities of surface area distresses along the site which included; cracks, potholes, rutting and edge failure, while secondary data from the FMPWH database included; natural moisture content, maximum dry density, specific gravity, liquid limit, plastic limit, liquidity index, optimum moisture content, California Bearing Ratio (CBR), percent of soil particles passing #200 sieve and AASHTO classification of the subgrade soil. A Pearson correlation analysis between the road pavement surface condition and the CBR value of the subgrade soil at 95% Confidence Level using a 1-tailed statistics for the test hypothesis revealed that, there was no dependency between the pavement surface condition and the corresponding CBR property of the subgrade soil.
Published: 9 June 2021
Aksaray University Journal of Science and Engineering, Volume 5, pp 46-64; https://doi.org/10.29002/asujse.908451
In this study, hydroxyapatite particles (HAp) were chemically synthesized by using co-precipitation method to determine their capabilities on the sorption of Zn(II) ions from aqueous solutions. HAp particles were chosen because of their low cost for production, high stability, easy to use, and effective sorption power. In order to determine the operation conditions of the adsorption system to be installed when this adsorbent is desired to be used in field applications, parameters such as system pH, initial Zn(II) concentration and adsorbent concentrations have been optimized. Properties and functional structure of the adsorbent materials were characterized by using SEM, FTIR, and EDX analyzes. The kinetic behavior of Zn(II) adsorption with HAp was consistent with the pseudo second order kinetic model. Additionally, the equilibrium states of the adsorption processes were studied by using Langmuir, Freundlich, Temkin, Scatchard and Dubinin–Radushkevich (D-R) isotherm models. The maximum sorption capacity HAp was obtained as 500 mg/g, and best removal value of 91% were determined at pH of 6.0, optimum adsorbent concentration of 3.75 g/L, in 25 mg/L Zn(II) concentration and optimum mixing time of 45 min. This study showed that the HAp can be considered an effective adsorbent on the Zn(II) removal from wastewater.
Published: 25 May 2021
Aksaray University Journal of Science and Engineering; https://doi.org/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; https://doi.org/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; https://doi.org/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; https://doi.org/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; https://doi.org/10.29002/asujse.820599
Published: 30 December 2020
Aksaray University Journal of Science and Engineering; https://doi.org/10.29002/asujse.767122
Published: 30 December 2020
Aksaray University Journal of Science and Engineering, Volume 4, pp 172-186; https://doi.org/10.29002/asujse.765097