Effect of pH Fluctuations in Saliva on Low-Temperature Degradation of Dental Monolithic Zirconia Restorations

Ender AKAN

Monolitik zirkonyum restorasyonlar, mükemmel mekanik özellikleri, biyouyumluluk ve estetiği ile bilinir. Ancak, düşük sıcaklık bozulmasına (LTD) eğilimlidirler. LTD, su veya su buharı varlığında 100 santigrat derecenin altındaki sıcaklıklarda zirkonyumun bozulmasına karşılık gelir. Metastabil tetragonal fazdan daha kararlı monoklinik faza bir faz dönüşümünü içerir. Bu faz dönüşümü, zirkonyumda mikro çatlaklara ve boyutsal değişikliklere neden olabilir, bu da mekanik mukavemetini ve uzun vadeli stabilitesini tehlikeye atabilir. Tükürük, elektrolitler, enzimler, proteinler ve bakteriler içeren k ...Daha fazlası

Control of Mobile Parallel Manipulator

BERK YILDIZ

This thesis is based on the development, kinematics analysis, and control of a novel mobile Euclidean parallel manipulator. The hybrid mobile parallel manipulator is designed to improve the disadvantages of mobile manipulators and parallel manipulators. This new design of mobile Euclidean parallel manipulator type robot manipulator is an improved type of both mobile platforms and parallel manipulators, and it is created by combining three degrees of freedom Euclidean platform with a mobile differential drive manipulator. To allow the design of this type of hybrid manipulator, the kinematics of ...Daha fazlası

A design of ethylene Removal non-woven textile by using natural zeolite and potassium permanganate = Doğal zeolitler ve potasyum permanganat kullanılarak etilen tutucu dokusuz yüzey tekstil ürününün tasarlanması

Duru, Ayşenur

A DESIGN OF ETHYLENE REMOVAL NON-WOVEN TEXTILE BY USING NATURAL ZEOLITE AND POTASSIUM PERMANGANATE ABSTRACT Ethylene has a significant role in plants development and maturing and isproduced as gas hormone by plants themselves. In 1 μL L-1 concentrations, it has beneficial effects for fresh vegetables and fruits (FFV) but when this gas is accumulated around the FFV it causes aging and deterioration. During the storage, transport and marketing it affects the quality and freshness of FFV. There are technologic solutions for eliminating the ethylene gas accumulating in storage atmosphere probl ...Daha fazlası

Development of a Tele-Physiotherapy Device to Remedy Elbow Joint with Mobile App Support

Arda SARPAY

The aim of this thesis was to develop a wearable tele-physiotherapy device that addresses the remote elbow joint rehabilitation. The developed device consists of a wearable exoskeleton equipped with servo motor, joint angle sensor, EMG sensor, battery and Wi-Fi module. By connecting with the Android mobile application, it enables real-time monitoring of EMG data and programming of personalized exercise programs. The device offers convenience and comfort to patients by eliminating the need for face-to-face physiotherapy sessions and aims to reduce treatment costs and treatment time. The develo ...Daha fazlası

Determination and Modeling of Shear Strength Behavior of Soil – Geosynthetic Interface

İnci ERTAM

Bu çalışmada, farklı zeminler ve geomembranlar (GM) arasındaki arayüzleri etkileyen mühendislik parametreleri, kür sıvısı, kür süresi ve normal gerilme sınıfı gibi çeşitli koşullar altında incelenmiştir. Ayrıca depolama sahaları gibi birden çok geosentetiğin (GS) bir arada kullanıldığı tasarımlarda, GS’ler arasında oluşan arayüzeylerde de potansiyel kayma yüzeyleri oluşabilir. Bu nedenle, bu çalışmada aynı zamanda GM ve geotekstiller arasındaki arayüzeyler de araştırılmıştır. İlk aşamada, GS’lerin ve zeminlerin mühendislik parametreleri laboratuvar deneyleri ile belirlenmiştir. İkinci a ...Daha fazlası

Simulation and design of a glider swarm robotics platform

Gül, Kasım

The main purpose of my thesis is to develop a Swarm Robotics Platform which will use Cellular Automata Glider model and generate itself with “Game of Life” rules. The method was experimentally tested with autonomous mobile robots and real-time PC based simulation software, in all cases very good paths were obtained with negligible processing effort, and low cost production. Presented results indicate that the Cellular Automata approach is a very promising method for real time path planning and Glider like robotic swarms can be used for self-replicating and moving swarm robots. We desig ...Daha fazlası

Effect of Coating Material on High Temperature Oxidation of Inconel 738LC Superalloy

Simge AVCI

Inconel 738LC alaşımı nikel bazlı bir süperalaşımdır ve genellikle gaz türbinlerinde, türbin nozullerinde ve türbin bıçaklarında kullanılmaktadır. Gaz türbin motoru bileşenlerinde kullanımı yaygın olan Inconel 738LC çalışma ortam koşulları sebebi ile yüksek sıcaklık ile birlikte yüksek korozyona da maruz kalmaktadır. Bu sebeple, bu malzemenin yüksek sıcaklık mukavemet değeri ve yüksek sıcaklık oksidasyon direnci büyük önem taşımaktadır. Bu çalışmada karbon elementinin Inconel 738 alaşımında mekanik ve mikroyapısal etkileri incelenmiştir. Oda sıcaklığında ve iki farklı yüksek sıcaklıktak ...Daha fazlası

Estimation of Accommodative Forces in Aging Human Eye

Leyla Nur TURHAL ÇALIŞKAN

Changes in mechanical properties of the human crystalline lens over the years result in loss of accommodation amplitude and eventually in presbyopia, a condition in which the focus-shifting ability of the eye diminishes. Some material property changes of aging human crystalline lenses have already been mapped over human life. Young’s modulus, anterior and posterior lens curvatures, lens thickness, and refractive index are examples of these well-studied properties. However, knowledge of forces applied to the crystalline lens for generating corresponding focus shifts has been limited to a few ag ...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

Printed Circuit Board Coil Based Electromagnetic Actuator Design For Micro/Milliscale Manipulation

Erdem Doguş AKKUŞ

Trends in nano and micro technologies have directed researchers' concern towards designing small-scale functional systems, i.e., MEMS, NEMS, etc. This study represents a design and implementation scheme for a class of small-scale actuators. Electromagnetic actuators currently used have disadvantages in small-scale applications since they cannot be produced in the desired sizes and compactness due to complex components. Using printed circuit board (PCB) based design strategies, scalable actuators can be produced in a smaller form factor and at a lower cost. The study aims to produce planar PCB ...Daha fazlası

Software Engineering Department Master Thesis

Mamadou Lamarana Diallo

Son zamanlarda yapay zeka (AI), sunduğu çözümler nedeniyle bilimsel araştırmaların tüm alanlarını işgal etti. Sağlık da bir istisna değil. Diyabet dünyadaki en yaygın hastalıklardan biridir. Komplikasyonlarından biri, hastanın görüşünü bulanıklaştırabilen veya bozabilen ve körlüğün ana nedenlerinden biri olan diyabetik retinopatidir. Diyabetik retinopatinin erken teşhisi tedaviye büyük ölçüde yardımcı olabilir. Yapay Zeka ve özellikle derin öğrenme alanındaki son gelişmeler, birçok hastalığı erken evrelerinde tahmin etmek, öngörmek ve teşhis etmek için kullanılabilecek iddialı çözümler sunmakt ...Daha fazlası

Aging Heat Treatment of Additive Manufacturing Maraging Steels in Nitrogen Containing Atmospheres

Derya Çakan

Additive Manufacturing (AM) is a manufacturing method that pushes the limits of imagination and eliminates the question of whether complex industrial products can be produced that cannot be obtained with traditional manufacturing methods. In this study, microstructure and mechanical properties of maraging steels produced by DMLS method and aged in different durations (6 and 9 hours) and atmospheres (Air, N2 and N2/H2) were investigated. When the SEM images were examined, it was ob-served that the molten pool boundaries did not disappear completely but became blur-red with increasing temperatur ...Daha fazlası