A study on Marangoni convection by the variational iteration method

In this letter, we will consider the use of the variational iteration method and Pad\'e approximant for finding approximate solutions for a Marangoni convection induced flow over a free surface due to an imposed temperature gradient. The solutions are compared with the numerical (fourth-order Runge Kutta) solutions.Comment: 6 pages, 2 figure

Haberleşme uydusu üzerine yerleştirilmiş gregoryen tipindeki haberleşme antenlerinin titreşim ve akustik sayısal analizleri.

The acoustic load during lift-off of the spacecraft rockets is one of the most destructive loads especially for the light and large space structures. This thesis mainly focuses on vibro-acoustic behavior of a large composite reflector satellite antenna. The study starts with manufacturing processes, material properties and design criteria of the antenna which is Gregorian type with two reflectors. Then, Finite Element Model (FEM) of the antenna which is prepared in HyperMesh is analyzed structurally with calculation of modal and frequency response in MSC. NASTRAN. The FEM model and results are adjusted by using the sine-sweep test results performed on a modal shaker. After obtaining proper FEM model, vibro-acoustic numerical model is constructed and solved in MSC. ACTRAN. One of the strongest parts of this thesis is presenting acoustic test results performed in a reverberant chamber which provides the diffuse sound field. In summary, this thesis presents manufacturing processes of satellite reflector antenna and examines the vibration and acoustic test responses and FEM results with their comparisons.Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Mechanical Engineering

The Differential Transformation Method and Pade Approximant for a Form of Blasius Equation

Boundary conditions in an unbounded domain, i.e. boundary condition at infinity, pose a problem in general for the numerical solution methods. The aim of this study is to overcome this difficulty by using Padé approximation with the differential transform method (DTM) on a form of classical Blasius equation. The obtained results are compared with, for the first time, the ones obtained by using a modified form of Adomian decomposition method (ADM). Furthermore, in order to see the consistency of solutions, they are also compared with the ones obtained by using variational iteration method (VIM)

The Approximate Solution of High-Order Linear Fractional Differential Equations with Variable Coefficients in Terms of Generalized Taylor Polynomials

In this paper, we have developed a new method called Generalized Taylor collocation method (GTCM), which is based on the Taylor collocation method, to give approximate solution of linear fractional differential equations with variable coefficients. Using the collocation points, this method transforms fractional differential equation to a matrix equation which corresponds to a system of linear algebraic equations with unknown Generalized Taylor coefficients. Generally, the method is based on computing the Generalized Taylor coefficients by means of the collocation points. This method does not require any intensive computation. Moreover, It is easy to write computer codes in any symbolic language. Hence, the proposed method can be used as effective alternative method for obtaining analytic and approximate solutions for fractional differential equations. The effectiveness of the proposed method is illustrated with some examples. The results show that the method is very effective and convenient in predicting the solutions of such problems

Kuğulu Parkın tarihi, sosyal, kültürel ve ekonomik etkileri

Ankara : İhsan Doğramacı Bilkent Üniversitesi İktisadi, İdari ve Sosyal Bilimler Fakültesi, Tarih Bölümü, 2013.This work is a student project of the The Department of History, Faculty of Economics, Administrative and Social Sciences, İhsan Doğramacı Bilkent University.by İbrahim Mert Öztürk.Öztürk, İbrahim Mert. HIST 200-11ÖZTÜRK HIST 200-11/10 2012-1