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  • Article
    Citation - WoS: 4
    Citation - Scopus: 2
    Partner Phubbing and Sleep Quality: Serial Mediation Models With Relationship Satisfaction and Perceived Stress
    (Sage Publications inc, 2024) Dikdere, Busra; Turkarslan, Kutlu Kagan
    The increasing integration of technology into our lives has been affecting our daily routines and even our sleeps. Being a relatively new concept, phubbing refers to the act of overly engaging with one's phone while dismissing those around in the social settings. In this context, partner phubbing involves individuals exhibiting this neglect in the presence of their romantic partners. Evidence suggests that higher partner phubbing may lead to lower relationship satisfaction and higher perceived stress. The aim of the present cross-sectional study was to examine whether relationship satisfaction and perceived stress mediate the relationship between partner phubbing and sleep quality. Four hundred twenty-three individuals (females = 78.5%, M-age = 29.19, SD = 6.87) participated in the study and completed the measures of partner phubbing, relationship satisfaction, perceived stress, and sleep quality. The results of the serial mediation analyses showed that partner phubbing was not a direct predictor of sleep quality. However, the relationship between partner phubbing and sleep quality was mediated by the four indirect paths through relationship satisfaction (beta = 0.04, p < .05), perceived stress (beta = 0.09, p < .05), relationship satisfaction-perceived stress (beta = 0.02, p < .05), and perceived stress-relationship satisfaction (beta = 0.00, p < .05). The findings suggest that partner phubbing may diminish sleep quality by reducing relationship satisfaction and increasing perceived stress levels. Alternatively, perceived stress exacerbated by partner phubbing could reduce relationship satisfaction, which eventually worsens sleep quality. Digital detox programs, group interventions, emotion-focused couple interventions, and stress management training can help overcome the effects of partner phubbing on sleep quality.
  • Article
    Citation - WoS: 44
    Citation - Scopus: 49
    A Neural Network-Based Approach for Calculating Dissolved Oxygen Profiles in Reservoirs
    (Springer London Ltd, 2003) Soyupak, S; Karaer, F; Gürbüz, H; Kivrak, E; Sentürk, E; Yazici, A
    A Neural Network (NN) modelling approach has been shown to be successful in calculating pseudo steady state time and space dependent Dissolved Oxygen (DO) concentrations in three separate reservoirs with different characteristics using limited number of input variables. The Levenberg-Marquardt algorithm was adopted during training. Pre-processing before training and post processing after simulation steps were the treatments applied to raw data and predictions respectively. Generalisation was improved and over-fitting problems were eliminated: Early stopping method was applied for improving generalisation. The correlation coefficients between neural network estimates and field measurements were as high as 0.98 for two of the reservoirs with experiments that involve double layer neural network structure with 30 neurons within each hidden layer. A simple one layer neural network structure with 11 neurons has yielded comparable and satisfactorily high correlation coefficients for complete data set, and training, validation and test sets of the third reservoir.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 7
    Trapping Centers and Their Distribution in Tl2ga2< Layered Single Crystals
    (Pergamon-elsevier Science Ltd, 2009) Isik, M.; Gasanly, N. M.
    Thermally stimulated current (TSC) measurements with current flowing perpendicular to the layers were carried out on Tl2Ga2Se3S layered single crystals in the temperature range of 10-260K. The experimental data were analyzed by using different methods, such as curve fitting, initial rise and isothermal decay methods. The analysis revealed that there were three trapping centers with activation energies of 12, 76 and 177 meV. It was concluded that retrapping in these centers was negligible, which was confirmed by the good agreement between the experimental results and the theoretical predictions of the model that assumes slow retrapping. The capture cross section and the concentration of the traps have been also determined. An exponential distribution of electron traps was revealed from the analysis of the TSC data obtained at different light illumination temperatures. This experimental technique provided values of 10 and 88 meV/decade for the traps distribution related to two different trapping centers. (C) 2009 Elsevier Ltd. All rights reserved.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Performance of Ge-Sandwiched Gase Layers
    (Springer, 2018) Qasrawi, A. F.; Qasrawı, Atef Fayez Hasan; Abdallah, Maisam M. A.; Qasrawı, Atef Fayez Hasan; Department of Electrical & Electronics Engineering; Department of Electrical & Electronics Engineering
    In the current work, we report the effect of sandwiching Ge between two stacked layers of GaSe. The GaSe and Ge-sandwiched GaSe were subjected to x-ray diffraction, optical spectrophotometry and impedance spectroscopy measurement and analysis. The presence of a Ge layer between two layers of GaSe was observed to cause uniform deformation and increase the absorption of light by GaSe. The response of the dielectric constant to incident light was also significantly enhanced by Ge sandwiching. In addition, Drude-Lorentz modeling of the imaginary part of the dielectric constant revealed that the layer of Ge layer between GaSe layers increased the drift mobility from 30.76 cm(2)/Vs to 52.49 cm(2)/Vs. It also enhanced the plasmon frequency without altering the free carrier density. Moreover, Ge improved the band filtering features of GaSe. In particular, it enhanced the sensitivity of the impedance response to the incident signal and increased the return loss factor of GaSe when it was used as a high band pass filter.
  • Conference Object
    Kinetics Studies on Glyceraldehyde Concentration of Bovine Lens Aldose Reductase
    (Wiley-blackwell, 2011) Onay, M.; Onay, M.; Coruh, N.; Isgor, S. B.
    [No Abstract Available]
  • Article
    Citation - WoS: 1
    Citation - Scopus: 2
    Existence of Solutions for Odd-Order Multi-Point Impulsive Boundary Value Problems on Time Scales
    (Walter de Gruyter Gmbh, 2022) Georgiev, Svetlin G.; Akgol, Sibel Dogru; Kus, Murat Eymen
    Using a fixed point theorem due to Schaefer, the existence of solutions for an odd-order m-point impulsive boundary value problem on time scales is obtained. The problem considered is of general form, where both the differential equation and the impulse effects are nonlinear. Illustrative examples are provided.
  • Article
    Citation - WoS: 22
    Citation - Scopus: 24
    Synthesis and Temperature-Tuned Band Gap Characteristics of Magnetron Sputtered Znte Thin Films
    (Elsevier, 2020) Isik, M.; Gullu, H. H.; Parlak, M.; Gasanly, N. M.
    Zinc telluride (ZnTe) is one of the attractive semiconducting compounds used in various optoelectronic devices. The usage of ZnTe in optoelectronic applications directs researchers to search its optical characteristics in great detail. For this purpose, structural and optical properties of magnetron sputtered ZnTe thin films were studied by means of x-ray diffraction and transmission spectroscopy measurements. Structural analyses indicated that ZnTe thin films having cubic crystalline structure were successfully grown on soda-lime glass substrates. Transmittance spectra in the 400-1000 nm were recorded in between 10 and 300 K temperature region. The analyses of absorption coefficient spectra resulted in band gap energies decreasing from around 2.31 (10 K) to 2.26 eV (300 K). Temperature dependency of gap energy was studied by Varshni and O'Donnell-Chen relations to determine various optical parameters like absolute zero temperature band gap energy, change of gap energy with temperature, phonon energy.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 14
    How Can We Get Benefits of Computer-Based Testing in Engineering Education?
    (Wiley, 2013) Cagiltay, Nergiz; Yaman, Seniz-Ozalp
    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 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 P&P and CBT. By comparing results with the previous studies, this study concludes that personal characteristics of test takers, the features of CBT 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 CBTs and P&P tests in chemistry courses will not vary. This finding is encouraging the educators to get benefits of CBTs without any affect on students' performance. (c) 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 21: 287293, 2013; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.20470
  • Article
    Citation - WoS: 39
    Citation - Scopus: 49
    Focus Variation Measurement and Prediction of Surface Texture Parameters Using Machine Learning in Laser Powder Bed Fusion
    (Asme, 2020) Ozel, Tugrul; Altay, Ayca; Kaftanoglu, Bilgin; Leach, Richard; Senin, Nicola; Donmez, Alkan
    The powder bed fusion-based additive manufacturing process uses a laser to melt and fuse powder metal material together and creates parts with intricate surface topography that are often influenced by laser path, layer-to-layer scanning strategies, and energy density. Surface topography investigations of as-built, nickel alloy (625) surfaces were performed by obtaining areal height maps using focus variation microscopy for samples produced at various energy density settings and two different scan strategies. Surface areal height maps and measured surface texture parameters revealed the highly irregular nature of surface topography created by laser powder bed fusion (LPBF). Effects of process parameters and energy density on the areal surface texture have been identified. Machine learning methods were applied to measured data to establish input and output relationships between process parameters and measured surface texture parameters with predictive capabilities. The advantages of utilizing such predictive models for process planning purposes are highlighted.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 9
    Existence and Uniqueness of Best Proximity Points Under Rational Contractivity Conditions
    (Walter de Gruyter Gmbh, 2016) Karapinar, Erdal; Roldan-Lopez-de-Hierro, Antonio-Francisco; Sadarangani, Kishin
    The main aim of this paper is to present some theorems in order to guarantee existence and uniqueness of best proximity points under rational contractivity conditions using very general test functions. To illustrate the variety of possible test functions, we include some examples of pairs of functions which are included in innovative papers published in the last years. As a consequence, we prove that our results unify and extend some recent results in this field.