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Öğe A Comparison for Grain Size Calculation of Cu-Zn Alloys with Genetic Programming and Neural Networks(Polish Acad Sciences Inst Physics, 2015) Karahan, I. H.; Ozdemir, R.Neural Networks (NN) and Genetic Programming (GP) were used as a new method for formulation of grain size of electrodeposited Cu1-xZnx alloys as a function of Zinc and Copper content both electrolyte and the alloy films produced by electrodeposition technique. To predict grain size a great number of different expression models genetic programming and neural network were conducted. Each model differs from the other with their linking function, number of genes, head size, and chromosomes. To generate databases for the new grain size formulations, testing and training sets in total of 134 samples were selected at different Zn and Cu ratios of components. 6 different input parameters were selected and the output parameter was grain size of the electrodeposited Cu-Zn alloys. The testing and training sets consisted of randomly selected 106 and 28 for the proposed models. All results in the models indicated an applicable performance for predicting grain size of the alloys and found reliable. The predicted model showed that all of the input parameters effected on the resulting grain size. The NN and GEP based formulation results are compared with experimental results and found to be quite reliable with a very high correlation (R2 = 0.995 for GEP and 0.999 for NN).Öğe Effect of solution Zn concentration on electrodeposition of CuxZn1-x alloys: materials and resistivity characterisation(Taylor & Francis Ltd, 2019) Ozdemir, R.; Karahan, I. H.CuxZn1-x alloy films were electrodeposited from non-cyanide sulphate solutions. Solution zinc ion concentration was varied, while that of copper was kept constant. Cyclic voltammetry studies from solutions showed that change in zinc ion molarity causes differences in electrolyte characteristics and resulting films. Morphology, elemental composition and phase structures of electrodeposited samples were characterised using SEM, EDS and XRD, respectively. Additionally, resistivity measurements were carried out on films using the four-point probe method. Results show that change of solution zinc concentration affects morphological, elemental and structural properties of deposited films, which consequently results in different electrical resistivity behaviour.Öğe Grain size calculation of Cu-Zn alloys using genetic programming; an alternative for Scherer's formula(Natl Inst Optoelectronics, 2015) Ozdemir, R.; Karahan, I. HakkiGenetic Programming (GP) was used as a new method for formulation of grain size of electrodeposited Cui_xZnx alloys as a function of Zinc and Copper content both electrolyte and the alloy films produced by electrodeposition technique. To predict grain size 48 different expression models were conducted. Each model differs from the other with their linking function, number of genes, head size, and chromosomes. To generate databases for the new grain size formulations, testing and training sets in total of 134 samples were selected at different Zn and Cu ratios of components. The testing and training sets consisted of randomly selected 106 and 28 for the proposed models. 6 different input parameters were selected as dspacing spacing, Zn and Cu % content in the electrolyte and thin films and the test FWHM of the thin films obtained by XRD results. The output parameter was grain size of the electrodeposited Cu-Zn alloys. All results in the models indicated an applicable performance for predicting grain size of the alloys and found reliable. The predicted model showed that all of the input parameters effected on the resulting grain size.Öğe Investigation of the Structural and Magnetic Properties of the Cobalt-Nickel Alloys Fabricated in Various Electrolyte Solutions(Polish Acad Sciences Inst Physics, 2017) Ozdemir, R.; Korkmaz, C. A.; Karahan, I. H.Cobalt-Nickel alloys have been widely used for decoration, in magnetic recording devices and corrosion resistance applications, etc. In this study, the influences of cobalt amount in electrolyte on the magnetic and structural properties of the electrodeposited Co-Ni alloys were investigated. An electrolyte solution, consisting of cobalt sulfate, nickel sulfate, nickel chloride and boric acid, was used in electrodeposition. The electrochemical investigation of Co-Ni alloys was completed using cyclic voltammetry and galvanostatic studies. The morphological and structural analyses of the alloys were performed using inductively coupled plasma, scanning electron microscopy, X-ray diffraction and vibrating sample magnetometer techniques. The effect of cobalt concentration on the magnetic properties, phase structure and grain size of the alloys was investigated. Magnetic hysteresis results indicate that the amount of the cobalt content in the electrolyte has a strong influence on the ferromagnetic behavior of fabricated alloys. Results of the study show that changing the electrodeposition parameters, such as composition of electrolyte solution, allows to fabricate alloys with different properties.Öğe A new modeling of electrical resistivity properties of ZnFe alloys using genetic programming(National Institute of Optoelectronics, 2010) Karahan, I.H.; Ozdemir, R.The electrical resistivity of electrodeposited Zn1-xFex alloys has been formulated as a function of temperature between the 10 and 330 K for an iron concentration x from 4 to 39 using Genetic Programming (GP) as a new tool. There are no well established formulations for predicting electrical resistivity properties of electrodeposited alloys related to film composition, electrodeposition bath composition and corrosion potential. Therefore, the objective of this paper is to develop robust formulations based on the experimental data and to verify the use of GP for generating the formulations for electrical resistivity of electrodeposited ZnFe alloys. To generate databases for the electrical resistivity formulations, training and testing sets in total of 260 samples were selected at different temperatures and ratios of components. The training and testing sets consisted of randomly selected 208 and 52 for the electrical resistivity. The paper showed that the GP based formulation appeared to be in line with the experimental data and was found to be quite reliable.
