Dynamics of Axisymmetric Drops Impacting onto Heterogeneous Surfaces

Atalay SEÇER

The way a droplet behaves when it lands on a surface depends on the characteristics of the surface and the flow conditions of the droplet. It can deposit, rebound, splash, etc. There is delimited research on how surface roughness and chemical composition affect the deformation of droplets upon impact, in comparison to the studies done on smooth surfaces. Our model uses two-phase flow to simulate the axisymmetric motion of droplets over surfaces with heterogeneities by combining the Navier-Stokes equations for motion with the Cahn-Hilliard equation for tracking the phase-field. We integrate the ...Daha fazlası

Evaluation Of The Property Acquisition Process Of Foreigners In Türkiye Using SWOT Technique

Demet Akbaba

Asırlar boyunca, ülkelerin siyasal güçleri ve varlıklarının sahip oldukları toprakların büyüklüğü ve konumu ile ilişkili olduğu görülmüştür. Bu nedenle, toprak neredeyse her dönemde bağımsızlık ve güç sembolü olarak kabul edilmiştir. Zamanla gelişerek bu durumu destekleyen ve şu anda tüm dünyada etkilerini aktif bir şekilde gösteren küreselleşme; ülkelerin sahip oldukları toprakların belirli kısımlarının yabancılara satışı yoluyla serbest dolaşımını mümkün kılmıştır. Yabancılara toprak satışı 1924 yılındaki ilk düzenleme ile beraber başlamıştır ve günümüzde de sürekliliğini korumaktadır. Köy y ...Daha fazlası

Numerical and Experimental Investigation of High Speed Hydrostatic Journal Bearings for Small Gas Turbines

Ahmet Yıldırım

Son yıllarda, hibrit mil rulmanlarının (hidrostatik ve hidrodinamik özelliklerin birleşimi) turbomakine uygulamalarında önemi önemli ölçüde artmıştır. Bu, yüksek şaft hızları, ağır yük taşıma kapasitesi ve geniş bir sıcaklık aralığında çalışma yeteneklerinden kaynaklanmaktadır. Hidrostatik rulmanlar, sürtünme yüzeylerini ayırmak için basınçlı sıvı kullanırken, hidrodinamik rulmanlar, ayrımı sağlamak için gövde hareketine ve geometrisine dayanır. Hibrit rulmanlar ise her iki türün avantajlarını birleştirerek performansı artırır. Bu çalışmada, kendinden desteklenen yapıları vurgulayan ve katmanl ...Daha fazlası

Development of Electromagnetic Wave Absorption Properties of Graphene-Based Nanocomposites by Using Stochastic Optimization Methods

Kemal Bartu Aydın

Today, with the developing telecommunications and electronic technologies for civilian and military purposes, electromagnetic (EM) applications have a wide usage area, including different frequency ranges, such as radar, wireless information transfer, and medical technologies, as well as radio frequencies. However, the broad use of these technologies causes EM wave pollution, so they have a devastating effect not only on the working functionalities of electronic devices but also on human health. Therefore, the need to develop these technologies to prevent EM wave pollution is increasing daily. ...Daha fazlası

Manufacturing Duplex Steel by Using Induction Furnaces and Characterization

Gülşah Uslu

Duplex steels are materials that contain ferrite and austenite phases in their structure, have high resistance to corrosion, and also show improved mechanical values. While the austenite in its structure provides general corrosion resistance and ductility, ferrite provides resistance to stress corrosion cracking and mechanical strength. Duplex steels have widespread use, especially in shipping and petrochemistry. The current production method of duplex steels, which are in demand with a wide usage area, is generally argon oxygen decarburization furnaces (AOD). In addition to the production met ...Daha fazlası

A preliminary offshore wind energy potential study for bay of İzmir: Quantifying the airflow distortion on local ferryboats for adjustment of wind data by 3D CFD analyses

Güngör, Şahin

Humankind have an interest to obtain marine meteorological data for decades, therefore, constant and mobile meteorological stations have been used for the correct measurements. These meteorological data include wind speed and direction, sea surface and air temperature and cloud cover. Ship-mounted anemometers have been used for meteorological observations, obtaining the wind speed data and climate change analysis. Wind data are especially gathered and reported by Voluntary Observing Ships (VOS). World Meteorological Organization (WMO) created the VOS program to ensure reporting of the wind dat ...Daha fazlası

Modelling, Analysis and Experimental Verification of Pneumatic Brake System

Güleryüz, İbrahim Can

As the technology develops, the development in vehicle safety becomes an area, which takes the attraction of the researchers who are working in automotive industry. Although systems like air bag system, lane departure warning system (LDWS) and tire pressure monitoring system (TPMS) improve the safety of the vehicle, main studies, in which advanced technology is used mostly focus on the brake system including anti-lock braking system (ABS), traction control system (TCS), electronic stability control (ESC), advanced emergency braking system (AEBS), adaptive cruise control (ACC). Thus, det ...Daha fazlası

The evaluation of innovative insulation materials for energy efficiency in civil engineering

Thermal insulation term is the most important measure that provides the thermal comfort which human being has been looking for as a natural habit from the first residential lifestyle begins. The inventions in this topic, especially has been arisen in last centuries and specifically in the last century it has been carried forward and both aesthetic and performance based products have been researched to be discovered. In the light of researches each in academic and practical fields, the hope of this demand to be provided is increased via innovative insulation materials. Accordingly, to c ...Daha fazlası

Development of vibration performances of hybrid laminated composite materials by using stochastic methods

In recent years, laminated composites are fairly utilized in marine, automotive, aerospace, military and other engineering applications because of their high specific modulus (ratio between the young modulus and the density) and high specific strength (ratio between strength and density). In addition to these features, fiber reinforced composites have inherent tailorability such as fiber orientation and stacking sequence and provide great possibilities to designers against isotropic materials. Determination of the fundamental frequency performance of laminated composite plate is crucial for th ...Daha fazlası

Nonlinear analysis of steel frames considering lateral Torsional buckling effect

The use of nonlinear analysis methods is widely preferred to determine the realistic behavior of the structures through the computer technologies developed in recent years. However, the stability problems that significantly affect the structure behavior are often neglected in nonlinear analysis and in computer programs that are frequently used to the realization of these analyses. Lateral torsional buckling behavior, which is one of the stability problems, is considered to be neglected in many studies using nonlinear analysis methods in the literature. As a result, the realistic behavior ...Daha fazlası

Detection of dyes in water using smartphone technology for environmental sustaınability

Kocakuşak Özdemir, Gizem

The goal of this thesis is to develop the applicability of an ultra-low cost, field-deployable, plastic fiber based smartphone spectrometer system to study dye adsorption from water. A custom cradle using smartphone’s built-in flash and camera was designed for visible absorbance spectroscopy without any need for external electrical components. We firstly investigated the performance of smartphone spectrometer for methylene blue (MB) absorbance in water with a detection limit of 0.5 ppm, and compared it to that of a commercial spectrometer. We elaborated on the contribution of image formats to ...Daha fazlası

Technical investgation for the use of textile waste fiber types in new generation composite plasters

Kalkan, Şevket Onur

Garment and textile production industry is one of the main sectors of our country. This sector is a major driving force in our developing economy. According to 2014 data, Turkey is the third country on textile export among the European countries. Besides, Turkey is the world's sixth largest garment exporter. With such a huge production power, in Turkey’s textile sector, waste and/or residual textile materials are composed depends on the large scale production, as in most of the other production sectors. Such waste materials in textile industry are the left materials from production stag ...Daha fazlası