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Article Citation - Scopus: 2Steady Mixed Convection in a Heated Lid-Driven Square Cavity Filled With a Fluid-Saturated Porous Medium(Springer Verlag, 2015) Pekmen,B.; Pekmen, Bengisen; Tezer-Sezgin,M.; Pekmen, Bengisen; Mathematics; MathematicsSteady mixed convection flow in a porous square cavity with moving side walls is studied numerically using the dual reciprocity boundary element method (DRBEM). The equations governing the two-dimensional, steady, laminar mixed convection flow of an incompressible fluid are solved for various values of parameters as Darcy (Da), Grashof (Gr), and Prandtl (Pr) numbers. The results are given in terms of vorticity contours, streamlines and isotherms. Further, average Nusselt number variations with respect to the problem parameters are also presented. The fluid flows slowly as Da decreases since the permeability of the medium decreases, and the increase in Grashof number causes the flow to pass to the natural convective behavior. DRBEM has the advantage of using considerably small number of grid points due to the boundary only nature of the method. This provides the numerical procedure computationally cheap and efficient. © Springer International Publishing Switzerland 2015.Conference Object Inverse Spectral Problems for Complex Jacobi Matrices(Springer New York LLC, 2013) Guseinov,G.S.The paper deals with two versions of the inverse spectral problem for finite complex Jacobi matrices. The first is to reconstruct the matrix using the eigenvalues and normalizing numbers (spectral data) of the matrix. The second is to reconstruct the matrix using two sets of eigenvalues (two spectra), one for the original Jacobi matrix and one for the matrix obtained by deleting the last row and last column of the Jacobi matrix. Uuniqueness and existence results for solution of the inverse problems are established and an explicit procedure of reconstruction of the matrix from the spectral data is given. It is shown how the results can be used to solve finite Toda lattices subject to the complex-valued initial conditions. © Springer Science+Business Media New York 2013.Article Steady mixed convection in a heated lid-driven square cavity filled with a fluid-saturated porous medium(Springer Verlag, 2015) Pekmen,B.; Tezer-Sezgin,M.Steady mixed convection flow in a porous square cavity with moving side walls is studied numerically using the dual reciprocity boundary element method (DRBEM). The equations governing the two-dimensional, steady, laminar mixed convection flow of an incompressible fluid are solved for various values of parameters as Darcy (Da), Grashof (Gr), and Prandtl (Pr) numbers. The results are given in terms of vorticity contours, streamlines and isotherms. Further, average Nusselt number variations with respect to the problem parameters are also presented. The fluid flows slowly as Da decreases since the permeability of the medium decreases, and the increase in Grashof number causes the flow to pass to the natural convective behavior. DRBEM has the advantage of using considerably small number of grid points due to the boundary only nature of the method. This provides the numerical procedure computationally cheap and efficient. © Springer International Publishing Switzerland 2015.Conference Object Citation - Scopus: 1Üç Katmanli Nesne-iliskisel Esleme Mimarisi için Otomatik Fonksiyonel Büyüklük Ölçümü(CEUR-WS, 2015) Demirel,H.; Özkan,B.[No abstract available]Conference Object Yazilim Mühendisliʇi Eʇitiminde Bitirme Projesi Dersinin Öʇrenci Bakiş Açisiyla Deʇerlendirilmesi(CEUR-WS, 2013) Karakaya,M.; Bostan,A.[No abstract available]Conference Object Üniversite Yazilim Mühendisligi Programlari Müfredatinin Swebok Kilavuzu Kullanilarak Degerlendirme ve İyilestirilmesi: Türkiye'de Bir Vaka Çalismasi(CEUR-WS, 2015) Garousi,V.; Mishra,A.; Yazici,A.[No abstract available]Conference Object Citation - Scopus: 2Synthesis of Tio2 Nanostructures Via Hydrothermal Method(American Ceramic Society, 2015) Bilgin,N.; Agartan,L.; Park,J.; Ozturk,A.Titania (TiO2) nanostructures were produced via hydrothermal method using amorphous TiO2 powders synthesized by the sol-gel precipitation process. The hydrothermal system was isolated from the environment and hydrothermal reactions were allowed to execute at 130 °C for 36 h at autogeneous pressure, and at a stirring rate of 250 rpm. Scanning electron microscopy (SEM) analysis revealed that TiO2 nanofibers formed instead of nanotubes upon utilization of amorphous TiO2 precursor. After hydrothermal synthesis, the powders were acid treated by HCl several times. X-ray diffraction (XRD) analysis identified that the synthesized powders were Na-titanate and remained Na-titanate even after subjecting to acidic treatments several times. The photocatalytic performance of the powders was evaluated by degradation of methylene blue (MB) solution in UV illumination. Results were compared with nanotubes which were synthesized previously using P25 commercial titania powder and have shown that TiO2 in tubular structure offers better photocatalytic performance for the degradation of MB solution under UV illumination as compared to fiber-like structure. Copyright © 2015 by The American Ceramic Society. All rights reserved.Conference Object Türkiye'de Yazilimin Temel Gösterge Alanlarda Gelisimi(CEUR-WS, 2016) Yazici,A.; Misra,A.; Özkan,B.; Cetin,S.[No abstract available]Conference Object Citation - Scopus: 1Piezoelectric Ultrasonic Motors Using Bulk Pzt and Utilizing Two Orthogonal Bending Modes of a Hollow Cylinder (part 2)(2005) Cagatay,S.; Uchino,K.; Koc,B.Our main objective was to design, fabricate and characterize piezoelectric ultrasonic motors for micromechatronic devices. Three different prototypes were fabricated. The stator part of the motors was composed of a composite structure; metal and piezoelectric ceramic plates. Owing to the partially square/partially circular outside surface, the stator had two degenerated bending modes that were orthogonal to each other. First stator was 10 mm in length. The outer and inner diameters were 2.4 mm and 1.6 mm, respectively. Dimensions of the second stator had been reduced by 50%. In the final design, length of the stator had reached to 4 mm and the rotor part of the motor had been changed from a solid rod to a spring. In addition, an optimization process was conducted on improving the displacement range of the stator of the piezoelectric micro-motor. When both modes were excited at a single resonance frequency, the resultant wobbling motion will provide higher displacement values, which in turn will provide higher torque.Editorial Photo Quiz; Anthrax or Orf?(Doc design informatics Co Ltd, 2019) Tulek, Necla; Kilic, Esra Kaya; Ertem, GunayTuncer; Yuksekkaya, Esra[No Abstract Available]
