Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article Citation - WoS: 1Citation - Scopus: 1Enhancement of Brazing Performance of Inconel 718 By Electroless Cobalt Coated Nickel-Based Brazing Alloys(Elsevier, 2025) Goynuk, Tansu; Esen, Ziya; Karakaya, IshakEffect of electroless cobalt-coated BNi-2 on the brazing performance of Inconel 718 was investigated in this study. A new method for modifying the microstructure and thermal properties of brazing alloys by incorporating cobalt through electroless deposition was introduced. This approach offers a more controlled and uniform alloy modification compared to conventional mechanical mixing techniques, enhancing the performance of the brazed joints. The introduction of cobalt into the filler material influences the microstructural evolution and refining the joint structure by reducing brittle precipitates. Microstructural analysis confirms that the Co-coated BNi-2 results in a more homogeneous joint with improved phase distribution. Mechanical characterization indicated that the shear strength increased nearly 4.5 times, while fracture strain improved approximately fourfold. Moreover, the cobalt addition raised the solidus temperature of the filler alloy by 25-30 degrees C, contributing to better high-temperature stability. These findings highlight the effectiveness of electroless cobalt coating in optimizing brazing alloys for demanding aerospace and high-temperature applications.Article Dielectric and Thermal Properties of the Ferroelectric NH4HSO4 Close to Phase Transitions(Elsevier, 2025) Kiraci, A.; Yurtseven, H.This work gives the analysis of the dielectric and thermal properties close to the second order and first order types of ferroelectric-paraelectric phase transitions in ferroelectrics, in particular, NH4HSO4. The power-law formula is used by adapting the Kouvel-Fisher (KF) method describing the magnetization (M) and magnetic susceptibility (chi M) in the case of the spontaneous polarization (PS) and the dielectric constant (& varepsilon;), respectively, in ferroelectric systems. Similar treatment is performed to describe the heat capacity (CP) and the thermal expansivity (proportional to P) close to the phase transitions in NH4HSO4. We show that the variations of PS and & varepsilon; with the temperature near the upper Curie point (TC1 = 270 K) exhibit linearity for the second order transition in NH4HSO4. A linear variation is also obtained between the CP and proportional to P with the temperature close to the lower Curie point (TC2 = 160 K) for the first order transition in this crystal. Experimental data are used from the literature for our analysis. Our approach given here to describe dielectric and thermal properties of NH4HSO4 close to the Curie points, can be applied to some other ferroelectric materials.Article Citation - Scopus: 1Finite Bivariate Biorthogonal I-Konhauser Polynomials(Elsevier, 2026) Lekesiz, Esra Guldogan; Cekim, Bayram; Ozarslan, Mehmet Ali; Güldoğan Lekesi̇z, EsraIn the present study, a finite set of biorthogonal polynomials in two variables, produced from Konhauser polynomials, is introduced. Some properties like Laplace transform, integral and operational representation, fractional calculus operators of this family are investigated. Also, we compute Fourier transform for this new set and discover a new family of finite biorthogonal functions with the help of Parseval's identity. Further, in order to have semigroup property, we modify this finite set by adding two new parameters and construct fractional calculus operators. Thus, integral equation and integral operator are obtained for the modified version.Article Citation - WoS: 6Citation - Scopus: 6Modeling the Transmission Dynamics of Middle Eastern Respiratory Syndrome Coronavirus with the Impact of Media Coverage(Elsevier, 2021) Fatima, BiBi; Alqudah, Manar A.; Zaman, Gul; Jarad, Fahd; Abdeljawad, ThabetMiddle East respiratory syndrome coronavirus has been persistent in the Middle East region since 2012. In this paper, we propose a deterministic mathematical model to investigate the effect of media coverage on the transmission and control of Middle Eastern respiratory syndrome coronavirus disease. In order to do this we develop model formulation. Basic reproduction number R-0 will be calculated from the model to assess the transmissibility of the (MERS-CoV). We discuss the existence of backward bifurcation for some range of parameters. We also show stability of the model to figure out the stability condition and impact of media coverage. We show a special case of the model for which the endemic equilibrium is globally asymptotically stable. Finally all the theoretical results will be verified with the help of numerical simulation for easy understanding.Article Citation - WoS: 1Citation - Scopus: 2Testing the Equality of Several Independent Stationary and Non-Stationary Time Series Models with Fractional Brownian Motion Errors(Elsevier, 2021) Mahmoudi, Mohammad Reza; Baleanu, Dumitru; Qasem, Sultan Noman; Mosavi, Amirhosein; Band, Shahab S.; S. Band, ShahabThis work is devoted to apply the parametric and nonparametric techniques to construct test of hypothesis about the equality of the probabilistic behaviors of several time series models with fractional Brownian motion errors fitted on several independent datasets. The accuracy and power of the introduced method are studied using the simulated and real datasets. The results indicate that the introduced approach is more powerful than other alternative approaches, in non-stationary cases. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Article Citation - WoS: 4Citation - Scopus: 4Artificial Neural Networks for Predicted Bending Properties of Additively Manufactured Pyramidal Lattice Truss Core Sandwich Structures(Elsevier, 2025) Karagozlu, Cem Onat; Ayli, Ece; Tanabi, Hamed; Sabuncuoglu, BarisAn Artificial Neural Network (ANN) model is developed to predict the mechanical behavior of pyramidal lattice truss core sandwich structures under bending load. The development process aims to optimize material use, enhance structural efficiency, and reduce analysis time for the developed ANN model. Key phases include specimen fabrication via additive manufacturing, experimental testing in four-point bending, and validation of the finite element model (FEM). Experimental tests on five specimens validated FEM simulations with a 4.5 % error rate. The ANN, trained on FEM data, accurately predicts reaction forces and stress components (sigma,, sigma 2, tau,2). Comparison of training algorithms (LM, Levenberg-Marquardt, BR, Bayesian Regularization, SCG, Scaled Conjugate Gradient) highlights LM's superior performance in convergence and MSE reduction (max. MSE value: 2.287), while BRexcels in generalization and robustness. Scaled Conjugate Gradient's performance was lower than the others. The ANN demonstrates high accuracy within the training range but shows limitations in extrapolation. Overall, this ANN model offers engineers a rapid and precise tool for predicting the mechanical behavior of these sandwich structures, reducing reliance on time-consuming FEM simulations and facilitating efficient design optimization across various engineering applications.Article Citation - WoS: 2Citation - Scopus: 2Integrating Recycled Asphalt Pavement and Warm Mix Additives for Enhanced Performance and Reduced Emissions in Asphalt Mixtures(Elsevier, 2025) Viktorovich, Gladyshev Nikolai; Almusawi, Ali; Shoman, Sarmad; Lupanov, Andrei P.; Albdairi, MustafaThis research explores the effects of integrating recycled asphalt pavement (RAP) with various warm mix asphalt (WMA) additives on the production and performance of asphalt concrete mixtures. The main goal is to improve these mixtures' mechanical properties and environmental sustainability by decreasing the production temperature and reducing harmful emissions. The WMA additives tested-CCBit 113 CE, Rediset WMX 8017, Evotherm J-1, Sylvaroad RP1000, ZycoTherm, Amphoteric type DAD-1, and Adgezol 3-TD-vary in composition, including wax-based, amide-based, polyol ether, and surfactant additives, each influencing asphalt properties differently. Laboratory experiments evaluated enhancements in density, compressive strength, water resistance coefficient, and water saturation. The findings show that these additives significantly boost the mechanical properties of asphalt concrete and lower production temperatures by 40-50 C, reducing it from 145 to 155 C to 100-110 degrees C and consequently decreasing emissions of harmful substances like carbon monoxide. Furthermore, the study features a field performance evaluation in partnership with industry collaborators at a pilot section on Yegoryevskoye Highway, Moscow, Russia. This thorough assessment confirms the practicality and advantages of combining RAP and WMA additives in asphalt concrete production, offering a sustainable approach to road construction.Article Citation - WoS: 2Citation - Scopus: 2Seismic Performance Assessment and Restoration Proposal for the 19th-Century Karacakaya Mosque(Elsevier, 2025) Sayin, Baris; Akan, Asli Er; Cosgun, Turgay; Er, Arzu; Samadi, Kamran; Uzdil, Oguz; Ormecioglu, Tevfik OguzPreserving historical buildings, as a shared heritage reflecting human civilization from the past to the present, is of vital importance. This study investigates the seismic behavior of the Karacakaya Village Mosque, constructed in 1879 with stone masonry walls and a hipped wooden roof, prior to its architectural restoration. The primary building and single minaret were modeled, and linear, nonlinear pushover, and kinematic analyses were performed in accordance with seismic guidelines. The response spectrum and the pushover analysis results indicated that both the main building and minaret met the local performance requirements. However, the kinematic limit analysis of the masonry walls revealed occurrences of overturning, lateral bending, and vertical bending failures. The seismic assessment concluded that restoring the mosque in its original form poses no structural harm. As part of the restoration project, a comprehensive survey study was conducted, followed by a restoration proposal informed by the architectural characteristics of Ottoman mosques in the region. The proposal involves removing non-original elements added to the mosque to restore its historical authenticity. This study presents a multi-stage reference methodology for the seismic analysis of historic masonry-wood structures, exemplified by an existing building with adequate seismic performance based on response spectrum analysis and nonlinear pushover analysis but exhibiting potential collapse mechanisms according to kinematic analysis. The findings underscore the necessity of including kinematic analyses in seismic codes and regulations for historic buildings. The proposed seismic assessment and restoration plan for this unique mosque will contribute significantly to preserving the historical value and sustainability of this heritage site. By considering the local collapse behavior in the analysis of the global behavior, a comparative assessment was made, which yielded more realistic conclusions regarding the structural performance of the mosque. The presented methodology also offers a comprehensive framework for engineers, by presenting practical guidelines for post-collapse interventions and contribute to the long-term preservation of monumental structures.Article Citation - WoS: 18Citation - Scopus: 19The General Caputo-Katugampola Fractional Derivative and Numerical Approach for Solving the Fractional Differential Equations(Elsevier, 2025) Sadek, Lakhlifa; Ldris, Sahar Ahmed; Jarad, FahdIn this manuscript, we present the general fractional derivative (FD) along with its fractional integral (FI), specifically the psi-Caputo-Katugampola fractional derivative (psi-CKFD). The Caputo-Katugampola (CKFD), the Caputo (CFD), and the Caputo-Hadamard FD (CHFD) are all special cases of this new fractional derivative. We also introduce the psi-Katugampola fractional integral (psi-KFI) and discuss several related theorems. An existence and uniqueness theorem for a psi-Caputo-Katugampola fractional Cauchy problem (psi-CKFCP) is established. Furthermore, we present an adaptive predictor-corrector algorithm for solving the psi-CKFCP. We include examples and applications to illustrate its effectiveness. The derivative used in our approach is significantly influenced by the parameters delta, gamma, and the function psi, which makes it a valuable tool for developing fractional calculus models.Book Citation - Scopus: 428Local Fractional Integral Transforms and Their Applications(Elsevier, 2015) Yang, X.J.; Baleanu, D.; Srivastava, H.M.Local Fractional Integral Transforms and Their Applications provides information on how local fractional calculus has been successfully applied to describe the numerous widespread real-world phenomena in the fields of physical sciences and engineering sciences that involve non-differentiable behaviors. The methods of integral transforms via local fractional calculus have been used to solve various local fractional ordinary and local fractional partial differential equations and also to figure out the presence of the fractal phenomenon. The book presents the basics of the local fractional derivative operators and investigates some new results in the area of local integral transforms. © 2016 Elsevier Ltd. All rights reserved.