Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 4Citation - Scopus: 4Synthesis, Characterization, and Antimicrobial Activities of 3-Hpaa Nanoparticles(Techno Press, 2021) Özdemir, Özgün Öykü; Soyer, FerdaEncapsulation of bioactive compounds (e.g., phenolic acids) into nanoparticles is a well-received technique in the searching for new antimicrobial agents against multidrug-resistant pathogens. Encapsulation can be a good technique to maintain the stability of phenolic acids against environmental conditions. In this study, 3-hydroxyphenylacetic acid (3-HPAA) was encapsulated into alginate-chitosan nanoparticles with the ion gelation technique. The characterization of loaded and unloaded nanoparticles was performed via dynamic light scattering, Fourier transform infrared spectroscopy, and scanning electron microscopy. According to the results, 3-HPAA loaded nanoparticles have spherical shapes with a diameter range of 40-80 nm and an average hydrodynamic diameter of 361.0 +/- 69.8 nm. The loading of 3-HPAA was successfully achieved based on the Fourier transform infrared spectra and encapsulation percentage studies. The antimicrobial effect of the nanoparticles in solution forms was tested on P. aeruginosa, S. epidermidis, MRSA, and MSSA. The results demonstrated that the 3-HPAA loaded alginate chitosan nanoparticle solution showed elevated antimicrobial effect due to the pH change by treatment with 1% acetic acid, and it displayed bacteriocidal effects in a strain-specific and dose-dependent manner. Therefore, the 3-HPAA loaded alginate chitosan nanoparticle solution was produced successfully with the bacteriocidal effect against serious pathogenic bacteria.Article Citation - WoS: 8Citation - Scopus: 8Free Vibration Analysis of Damaged Composite Beams(Techno Press, 2015) Cünedioğlu, Yusuf; Beylergil, BertanIn this study, free vibration analyses of symmetric laminated cantilever and simply supported damaged composite beams are investigated by using finite element method (FEM). Free vibration responses of damaged beams are examined using Euler Bernoulli beam and classical lamination theories. A computer code is developed by using MATLAB software to determine the natural frequencies of a damaged beam. The local damage zone is assumed to be on the surface lamina of the beam by broken fibers after impact. The damaged zone is modeled as a unidirectional discontinuous lamina with 0 degrees orientations in this study. Fiber volume fraction (v(f)), fiber aspect ratio (L-f/d(f)), damage length (L-D) and its location (lambda/L), fiber orientation and stacking sequence parameters effects on natural frequencies are investigated. These parameters are affected the natural frequency values significantly.Article Citation - WoS: 5Citation - Scopus: 8Comparative Dynamic Analysis of Axially Loaded Beams on Modified Vlasov Foundation(Techno Press, 2016) Hızal, Çağlayan; Çatal, Hikmet HüseyinVibration analysis of the beams on elastic foundation has gained the great interest of many researchers. In the literature, there are many studies that focus on the free vibration analysis of the beams on one or two parameter elastic foundations. On the other hand, there are no sufficient studies especially focus on the comparison of dynamic response including the bending moment and shear force of the beams resting on Winkler and two parameter foundations. In this study, dynamic response of the axially loaded Timoshenko beams resting on modified Vlasov type elastic soil was investigated by using the separation of variables method. Governing equations were obtained by assuming that the material had linear elastic behaviour and mass of the beam was distributed along its length. Numerical analysis were provided and presented in figures to find out the differences between the modified Vlasov model and conventional Winkler type foundation. Furthermore, the effect of shear deformation of elastic soil on the dynamic response of the beam was investigated.Article Citation - WoS: 23Citation - Scopus: 23Free Vibration Analysis of Laminated Composite Beam Under Room and High Temperatures(Techno Press, 2014) Cünedioğlu, Yusuf; Beylergil, BertanThe aim of this study is to investigate the effects of the beam aspect ratio(L/h), hole diameter, hole location and stacking layer sequence ([0/45/-45/90]s, [45/0/-45/90]s and [90/45/-45/0]s) on natural frequencies of glass/epoxy perforated beams under room and high (40, 60, 80, and 100°C) temperatures for the common clamped-free boundary conditions (cantilever beam). The first three out of plane bending free vibration of symmetric laminated beams is studied by Timoshenko's first order shear deformation theory. For the numerical analyses, ANSYS 13.0 software package is utilized. The results show that the hole diameter, stacking layer sequence and hole location have important effect especially on the second and third mode natural frequency values for the short beams and the high temperatures affects the natural frequency values significantly. The results are presented in tabular and graphical form. © 2014 Techno-Press, Ltd.
