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  • Article
    Paper-Based Versus Computer-Based Testing in Engineering Education
    (IEEE EDUCON Education Engineering 2010 – The Future of Global Learning Engineering Education, 2010) Çağıltay, Nergiz; Özalp Yaman, Şeniz
    Using computers for assessment can provide several benefits for educators and test-takers. However, in the literature, there is no consensus on the equivalence of paper-and-pencil and computer-based test environments. Accordingly, more evidences are needed especially for the engineering education. In this study, students’ performance on different test modes was evaluated on 209 first year engineering students of a chemistry course. The results of this study showed that, there is no significant performance difference between paper-and-pencil and computer based tests. By comparing results with the previous studies, this study concludes that, personal characteristics of test takers, the features of computer-based testing systems and the test content are all possible confounding factors when comparing test modes and need to be considered by the implementers. The results of this study show that, once these factors are controlled, students’ performance on computer-based tests and paper-and-pencil tests in chemistry courses for the engineering students will not vary. This finding is encouraging the educators to get benefits of computer-based tests without any affect on students’ performance.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 10
    Ann-Assisted Forecasting of Adsorption Efficiency To Remove Heavy Metals
    (Tubitak Scientific & Technological Research Council Turkey, 2019) Buaısha, Magdi; Balku, Şaziye; Yaman, Şeniz Özalp; Özalp Yaman, Şeniz
    In wastewater treatment, scientific and practical models utilizing numerical computational techniques suchas artificial neural networks (ANNs) can significantly help to improve the process as a whole through adsorption systems.In the modeling of the adsorption efficiency for heavy metals from wastewater, some kinetic models have been used such as pseudo first-order and second-order. The present work develops an ANN model to forecast the adsorption efficiency of heavy metals such as zinc, nickel, and copper by extracting experimental data from three case studies. To do this, we apply trial-and-error to find the most ideal ANN settings, the efficiency of which is determined by mean square error (MSE) and coefficient of determination (R2). According to the results, the model can forecast adsorption efficiency percent (AE%) with a tangent sigmoid transfer function (tansig) in the hidden layer with 10 neurons and a linear transferfunction (purelin) in the output layer. Furthermore, the Levenberg–Marquardt algorithm is seen to be most ideal for training the algorithm for the case studies, with the lowest MSE and high R2 . In addition, the experimental results and the results predicted by the model with the ANN were found to be highly compatible with each other.
  • Article
    How Can We Get Benefits of Computer-Based Testing in Engineering Education?
    (Computer Applications in Engineering Education, 2010) Çağıltay, Nergiz; Özalp Yaman, Şeniz
    Using computers for assessment can provide several benefits for educators and test-takers. However, in the literature, there is no consensus on the equivalence of paper-and-pencil (P&P) and computer-based test (CBT) environments. Additionally, these studies fail to address the engineering domain. Our main assumption is that, if we could define the confounding factors to satisfy that these two versions of the tests provide equivalent results, then especially in the first year courses of the engineering education programs, we could get several benefits of the CBT environments. Accordingly, in this study, students' performance o different test modes waws evaluated on 209 first year engineering students of a chemistry course. The results of this study showed that there is no significant performance difference between P&P and CBT. By comparing results with the previous studies, this study concludes that personal characteristics of test talers, the features of CBT systems, and the test content are all possible confounding factors when comparing test modes anf need to be considered by the implementers. The results of this study show that once these factors are controlled, students' performance on CBTs and P&P tests in chemistry courses will not vary. This finding is encourging the educators to get benefits of CBTs without any affect on students' performance.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 3
    Spectroelectrochemical Investigations of Pyrimidine-2 Binuclear Platinum(iii) Complexes
    (Pergamon-elsevier Science Ltd, 2014) Ozbek, Ozge; Özalp Yaman, Şeniz; Ozalp-Yaman, Seniz; Ozkan, Ilker; Onal, Ahmet M.; Isci, Huseyin; Özalp Yaman, Şeniz; Chemical Engineering; Chemical Engineering
    The electrochemical behavior of the binuclear platinum(III-III) complexes [Pt-2(C4H3N2S)(4)X-2] (C4H3N2S- = pyrimidine-2-thionate; X- = Cl--,Cl- Br--,Br- I-) have been studied by cyclic voltammetry and insitu spectroelectrochemistry in an acetonitrile-tetrabutylammonium tetrafluoroborate solventelectrolyte couple. An irreversible metal based reduction appears during the cathodic scan for each of the three complexes. The changes in UV-Vis spectra observed in-situ during the reductive electrolysis indicate that all three complexes give the same product, [Pt-2(C4H3N2S)(4)], with a Pt(II)-Pt(II) system. The changes in the reduction potentials of the complexes on changing the axial ligands are interpreted by the changes in the energy of the LUMO level, which is determined by the degree of sigma- and it-interactions of the axial halide ligands with the metal atoms. DFT (B3LYP/LanL2DZ) calculations support our experimental data. (c) 2014 Elsevier Ltd. All rights reserved.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 7
    Simultaneous Novel Synthesis of Conducting and Non-Conducting Halogenated Polymers by Electroinitiation of (2,4,6-Trichloro or 2,6-Dichlorophenolato)ni(ii) Complexes
    (Elsevier Sci Ltd, 2005) Özalp-Yaman, S; Özalp Yaman, Şeniz; Bastürkmen, M; Kisakürek, D; Özalp Yaman, Şeniz; Chemical Engineering; Chemical Engineering
    NiL2(Ph)(2)(.)xH(2)O [L=3,5-dimethylpyrazole or N-methyl imidazole; Ph=DCP or TCP; x=0, 1 or 3] complexes were synthesised and characterised by analytical and spectroscopic methods using elemental analysis and FTIR. The electrochemical behavior of the complexes was studied by cyclic voltammetry in tetrabutylammoniumtetrafluoroborate-N,N-dimethylformamide electrolyte-sol vent couple. Cyclic voltammogram of the complexes displayed two-step oxidation processes under the nitrogen gas atmosphere. The polymerization of the complexes was accomplished in the same solvent-electrolyte couple by the constant potential electrolysis of NiL2(Ph)(2)(.)xH(2)O, synthesizing the poly(di- or monochlorophenylene oxide)s via free radical mechanism. The simultaneous polymerization of non-conducting polymer and conducting polymer (the conductivity of 0.7 S cm(-2)) were achieved by electroinitiated polymerization of Ni(DMPz)(2)(TCP)(2). The structural analysis of the polymers were performed using FTIR, H-1 NMR and C-13 NMR spectroscopic techniques and DSC for the thermal analysis. The kinetics of the polymerization was followed by in situ UV-vis spectrophotometer during the electrolysis. The low temperature ESR spectrum of the electrolysis solution also confirmed the formation of phenol radical (g=2.0028). One electron oxidation process of NiL2(DCP)(2)(.)xH(2)O produces a new Ni(II) complex, Ni(L-L)(DCP)(2)(S) by the rapid decomposition of (NiL2)-L-III(DCP)(2) into a ligand radical producing a singlet with the g value of 2.0015. Second electron oxidation process generates oligemers, which could not be isolated from the electrolyte solution. (c) 2005 Elsevier Ltd. All rights reserved.