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Istanbul, Turkey

Yıldız Technical University is a technical university dedicated to engineering science and is one of the most prominent educational institutions in Istanbul, Turkey. The central campus lies within the Beşiktaş district. The new Davutpaşa campus lies within the Esenler district. 10 faculty, 3 vocational schools, and 2 institue. Wikipedia.


Allahverdiyev A.M.,Yildiz Technical University
Future microbiology | Year: 2011

Nanotechnology is the creation of functional materials, devices and systems at atomic and molecular scales (1-100 nm), where properties differ significantly from those at a larger scale. The use of nanotechnology and nanomaterials in medical research is growing rapidly. Recently, nanotechnologic developments in microbiology have gained importance in the field of chemotherapy. Bacterial strains that are resistant to current antibiotics have become serious public health problems that raise the need to develop new bactericidal materials. Metal oxide nanoparticles, especially TiO(2) and Ag(2)O nanoparticles, have demonstrated significant antibacterial activity. Therefore, it is thought that this property of metal oxide nanoparticles could effectively be used as a novel solution strategy. In this review, we focus on the unique properties of nanoparticles, their mechanism of action as antibacterial agents and recent studies in which the effects of visible and UV-light induced TiO(2) and Ag(2)O nanoparticles on drug-resistant bacteria have been documented. In addition, from to previous results of our studies, antileishmanial effects of metal oxide nanoparticles are also demonstrated, indicating that metal oxide nanoparticles can also be effective against eukaryotic infectious agents. Conversely, despite their significant potential in antimicrobial applications, the toxicity of metal oxide nanoparticles restricts their use in humans. However, recent studies infer that metal oxide nanoparticles have considerable potential to be the first-choice for antibacterial and antiparasitic applications in the future, provided that researchers can bring new ideas in order to cope with their main problem of toxicity. Source


Simsek M.,Yildiz Technical University
Composite Structures | Year: 2010

Vibration of a functionally graded (FG) simply-supported beam due to a moving mass has been investigated by using Euler-Bernoulli, Timoshenko and the third order shear deformation beam theories. The material properties of the beam vary continuously in the thickness direction according to the power-law form. The system of equations of motion is derived by using Lagrange's equations. Trial functions denoting the transverse, the axial deflections and the rotation of the cross-sections of the beam are expressed in polynomial forms. The constraint conditions of supports are taken into account by using Lagrange multipliers. In this study, the effects of the shear deformation, various material distributions, velocity of the moving mass, the inertia, Coriolis and the centripetal effects of the moving mass on the dynamic displacements and the stresses of the beam are discussed in detail. To validate the present results, the dynamic deflections of the beam under a moving mass are compared with those of the existing literature and a comparison study for free vibration of an FG beam is performed. Good agreement is observed. The results show that the above-mentioned effects play a very important role on the dynamic responses of the beam and it is believed that new results are presented for dynamics of FG beams under moving loads which are of interest to the scientific and engineering community in the area of FGM structures. © 2009 Elsevier Ltd. All rights reserved. Source


Simsek M.,Yildiz Technical University
Composite Structures | Year: 2010

In this paper, non-linear dynamic analysis of a functionally graded (FG) beam with pinned-pinned supports due to a moving harmonic load has been performed by using Timoshenko beam theory with the von-Kármán's non-linear strain-displacement relationships. Material properties of the beam vary continuously in thickness direction according to a power-law form. The system of equations of motion is derived by using Lagrange's equations. Trial functions denoting transverse, axial deflections and rotation of the cross-sections of the beam are expressed in polynomial forms. The constraint conditions of supports are taken into account by using Lagrange multipliers. The obtained non-linear equations of motion are solved with aid of Newmark- β method in conjunction with the direct iteration method. In this study, the effects of large deflection, material distribution, velocity of the moving load and excitation frequency on the beam displacements, bending moments and stresses have been examined in detail. Convergence and comparison studies are performed. Results indicate that the above-mentioned effects play a very important role on the dynamic responses of the beam, and it is believed that new results are presented for non-linear dynamics of FG beams under moving loads which are of interest to the scientific and engineering community in the area of FGM structures. © 2010 Elsevier Ltd. Source


Simsek M.,Yildiz Technical University
Nuclear Engineering and Design | Year: 2010

In this paper, fundamental frequency analysis of functionally graded (FG) beams having different boundary conditions is analyzed within the framework of the classical, the first-order and different higher-order shear deformation beam theories. The material properties of the beams vary continuously in the thickness direction according to the power-law form. Two types of formulation are developed. In the first formulation, total bending rotation measured on the beam middle surface is taken as unknown function whereas the shear rotation measured on the beam middle surface is taken as unknown function in the second formulation. The frequency equation is obtained by using Lagrange's equations and the boundary conditions of beams are satisfied with Lagrange multipliers. The unknown functions denoting the axial and the transverse deflections, the bending and the shear rotations of the cross-section of the beam are expressed in the polynomial form. In this study, the effects of slenderness ratio, material variations, the different formulations and the beam theories on the fundamental frequencies are examined. It is believed that the tabulated results will be a reference with which other researchers can compare their results. © 2009 Elsevier B.V. All rights reserved. Source


Bildirici M.E.,Yildiz Technical University
Biomass and Bioenergy | Year: 2013

This paper investigates the short-run and long-run causality analysis between biomass energy consumption and economic growth in the selected 10 developing and emerging countries by using the Autoregressive Distributed Lag bounds testing (ARDL) approach of cointegration and error correction models. It covers annual data from 1980 to 2009. The cointegration test results show that there is cointegration between the biomass energy consumption and the economic growth in nine of the ten countries (Argentina, Bolivia, Cuba, Costa Rica, El Salvador, Jamaica, Nicaragua, Panama, Paraguay, Peru). The cointegration test results show that there is no cointegration between the biomass energy consumption and the economic growth in one of the ten countries (Paraguay). © 2012 Elsevier Ltd. Source

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