WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
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Article Comparative Analysis of Impedance Matching Techniques in Wireless Power Transfer Efficiency: A Focus on Resonant, Adaptive, and Hybrid Approaches(Springer, 2025) Hatem, Sude; Kurt, ErolWireless power transfer (WPT) efficiency is highly dependent on impedance matching; however, comparative analyses of matching techniques under dy namic operating conditions remain limited. This study presents a systematic evaluation of three impedance matching approaches, namely resonant, adaptive, and hybrid, via theoretical modeling and numerical simulations. The results prove that adaptive impedance matching maintains stable efficiency (90.0% +/- 0.9%) in load variations (20-100 Omega ), coil misalignment (0<bold>degrees</bold>-30<bold>degrees</bold>), and transmission distances (0.1-1 cm), with minimal fluctuations. In contrast, resonant matching shows the best efficiency (i.e., 95%) under ideal conditions (10 MHz, 0<bold>degrees</bold> misalignment, 50 Omega load) but degrades rapidly to <50% under deviation conditions (e.g., 30 misalignment or 1 cm distance). The hybrid solution yields a balanced compromise that maintaining 85-92% efficiency in larger operating ranges. Quantitative metrics-the fluctuation rate (adaptive: 0.07 vs. resonant: 0.15) and stability index (adaptive: 102 vs. resonant: 20)-exhibit adaptive matching's superior dynamic performance. These find ings present practical advice on selecting impedance matching techniques in real WPTapplications, such as electric vehicle charging and medical implants, where stability under variability is paramount.Article Citation - WoS: 2Citation - Scopus: 1Interfacial Behavior and Diffusion Mechanisms of Bni-2 Brazing on Titanium Alloy: Experimental and Molecular Dynamics Insights(Springer, 2025) Goynuk, Tansu; Esen, Ziya; Karakaya, IshakContextJoining titanium alloys, particularly Ti-6Al-4V, is crucial in aerospace applications where reliable, high-performance joints are needed. Brazing offers an effective solution, enabling the joining of dissimilar materials without melting the base metals. However, optimizing the wetting and diffusion behavior of filler metals remains a challenge. This study investigates the high-temperature interaction between BNi-2 filler alloy and Ti-6Al-4V. Boron, the primary melting point depressant in BNi-2, was examined due to its small atomic size and interstitial diffusion mechanism. Elevated temperatures led to improved wetting, reflected by decreased contact angles. Both wetting angles and boron diffusion coefficients were obtained through molecular dynamics simulations and experimental measurements, showing reasonable correlation. These results provide valuable insight into interfacial mechanisms and support further optimization of brazing parameters.MethodsMolecular dynamics simulations were performed using LAMMPS to analyze the temperature-dependent wetting behavior of molten BNi-2 on Ti-6Al-4V and track atomic-scale diffusion. Initial atomic configurations were modeled and simulated under various conditions. Trajectory data were analyzed using OVITO for structural evolution. Boron diffusion was evaluated by calculating mean square displacement from LAMMPS outputs. These values were used to derive diffusion coefficients and activation energies. Parallel experiments were conducted to assess wetting angles and diffusion behavior, and simulation results were compared with experimental data. The consistency between both approaches highlights the reliability of the modeling framework in capturing essential mechanisms during the brazing process.Conference Object Citation - WoS: 12Citation - Scopus: 11Md Study of Energetics, Melting and Isomerization of Aluminum Microclusters(Springer, 2006) Boyukata, Mustafa; Guvenc, Ziya B.Voter and Chen version of an Embedded Atom Model has been applied to study the locally stable structures, energies, melting, isomerization and growth patterns of small aluminum clusters, Al(n), in the size range of n = 2 - 13. Using molecular dynamics and thermal quenching simulations, the global minima and the other locally stable structures have been distinguished from those stationary structures that correspond to saddle points of the potential energy surface. A large number (10000) of independent initial configurations generated at high temperatures has been used to obtain the stable isomers, and the probabilities of sampling different basins of attractions, for each size of the clusters. Their energy spectra have been determined and melting, and isomerization dynamics are investigated.Conference Object Citation - WoS: 2Citation - Scopus: 4Estimation of Cross Sections for Molecule-Cluster Interactions by Using Artificial Neural Networks(Springer, 2006) Boyukata, Mustafa; Kocyigit, Yucel; Guvenc, Ziya B.The cross sections Of D-2 (v,j) + Ni-n (T), n = 19 and 20, collision systems have been estimated by using Artificial Neural Networks (ANNs). For training, previously determined cross section values via molecular dynamics simulation have been used. The performance of the ANNs for predicting any quantities in molecule-cluster interaction has been investigated. Effects of the temperature of the clusters and the rovibrational states of the molecule are analyzed. The results are in good agreement with previous studies.Article Citation - WoS: 3Numerical Investigation of Two Fractional Operators for Time Fractional Delay Differential Equation(Springer, 2024) Chawla, Reetika; Kumar, Devendra; Baleanu, DumitruThis article compared two high-order numerical schemes for convection-diffusion delay differential equation via two fractional operators with singular kernels. The objective is to present two effective schemes that give (3-alpha)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(3-\alpha )$$\end{document} and second order of accuracy in the time direction when alpha is an element of(0,1)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha \in (0,1)$$\end{document} using Caputo and Modified Atangana-Baleanu Caputo derivatives, respectively. We also implemented a trigonometric spline technique in the space direction, giving second order of accuracy. Moreover, meticulous analysis shows these numerical schemes to be unconditionally stable and convergent. The efficiency and reliability of these schemes are illustrated by numerical experiments. The tabulated results obtained from test examples have also shown the comparison of these operators.Article An Q-Uniformly Convergent Technique for Singularly Perturbed Problems, With an Interior Turning Point Occurring in Chemical Processes(Springer, 2025) Kumari, Parvin; Kumar, Devendra; Baleanu, DumitruA parameter-uniform solution is presented for singularly perturbed turning point problems with twin boundary layers. A fitted mesh is created in order to resolve the layers, and the provided equation is discretized using the cubic B-spline basis functions on this mesh. For the analytic solution and its derivatives, asymptotic bounds are provided. A brief analysis shows that the method is first-order precise in time and second-order accurate (up to a logarithm factor) in space, and that it is uniformly convergent regardless of the minuscule parameter. Two test problems are offered in order to verify the theoretical results.Article Citation - WoS: 5Rouge Wave, W-Shaped, Bright, and Dark Soliton Solutions for a Generalized Quasi-1d Bose-Einstein Condensate System With Local M-Derivative(Springer, 2022) Latif, Mohamed S. Abdel; Baleanu, Dumitru; Kader, Abass H. AbdelIn this paper, a generalized quasi-1D Bose-Einstein condensate system with contact repulsion and dipole-dipole attraction (QBECS) and with the local M-derivative of order alpha is introduced. Using similarity transformation, the generalized QBECS is transformed into the same system but with constant coefficients under certain conditions. Finally, the travelling wave transformation is used for getting rogue waves and soliton solutions for the original equation. The effect of the fractional order alpha on the wave profile is discussed using some figures.Article Citation - Scopus: 1Response Bias in Numerosity Perception at Early Judgments and Systematic Underestimation(Springer, 2022) Inan, Asli Bahar; Kilic, AsliMental number representation relies on mapping numerosity based on nonsymbolic stimuli to symbolic magnitudes. It is known that mental number representation builds on a logarithmic scale, and thus numerosity decisions result in underestimation. In the current study, we investigated the temporal dynamics of numerosity perception in four experiments by employing the response-deadline SAT procedure. We presented random number of dots and required participants to make a numerosity judgment by comparing the perceived number of dots to 50. Using temporal dynamics in numerosity perception allowed us to observe a response bias at early decisions and a systematic underestimation at late decisions. In all three experiments, providing feedback diminished the magnitude of underestimation, whereas in Experiment 3 the absence of feedback resulted in greater underestimation errors. These results were in accordance with the findings that suggested feedback is necessary for the calibration of the mental number representation.Article Citation - WoS: 22Citation - Scopus: 19Laser Array Beam Propagation Through Liver Tissue(Springer, 2020) Baykal, Yahya; Ata, Yalcin; Gokce, Muhsin CanerLaser array beam propagating through mouse liver tissue is investigated. The turbulence power spectrum of the liver tissue is employed in the extended Huygens-Fresnel method to obtain an optical intensity profile and beam broadening at the observation point in biological liver tissue. Variations of the beam profile and the beam broadening are simulated based on the number of beamlets, source size, wavelength and the ring radius of the array. A biological tissue, illuminated by the laser array beam, exhibits different beam profiles and beam spot radius variations when the number of beamlets, source size, wavelength and the ring radius of the laser array beam are varied. Examining these variations observed in the propagated optical beam and comparing them with the test cases, abnormalities such as cancer and tumor in a biological liver tissue can be diagnosed.Article Citation - WoS: 3Citation - Scopus: 2On the Lebesgue Constants(Springer, 2020) Kushpel, A. K.We present the solution of a classical problem of approximation theory about the sharp asymptotics of Lebesgue constants or the norms of Fourier-Laplace projections on the real sphere S-d, in complex P-d (C) and quaternionic P-d(H) projective spaces, and in the Cayley elliptic plane P-16(Cay). In particular, these results supplement the sharp asymptotics established by Fejer (1910) in the case of S-1 and by Gronwall (1914) in the case of S-2.