Geometrical Optimization of Dimpled Double-Pipe Heat Exchangers for Nanofluid-based Natural Circulation Loops Operating at Lower Temperatures

Nur Çobanoğlu

Excessive use of global energy sources causes negative environmental impacts and a reduction in the available energy resources. Therefore, energy efficiency is the main scope of engineering studies. Since household refrigeration accounts for a large portion of the energy consumption rate in buildings, several innovative techniques have been developed to improve the energy efficiency of vapor compression refrigeration systems. Suction line heat exchangers are considered one of these techniques and they are used to avoid the presence of liquid at the compressor and to prevent sweating on the suc ...Daha fazlası

Estimation of Building Height from ICESat-2/ATLAS and Airborne LiDAR Data Using Machine Learning Algorithms

Aslıhan Yücel

The height of buildings in cities are of critical importance to urban planning and sustainable growth, as these factors are closely linked to environmental, economic, social, and aesthetic elements that shape the structure and character of cities. The main purpose of this study is to calculate building heights using machine learning algorithms based on airborne LiDAR and ICESat-2 data in urban areas. Sub-objectives of the study to achieve the main objective are: (a) investigate the relationships between spaceborne and airborne LiDAR data and integrate the data, (b) investigate the performance ...Daha fazlası

Characterization of Clay brick materials produced with red mud and nut shell wastes for building applications

Çam, Ata Sadık

In this study, clay based brick with micro pores was developed for thermal insulation in the building materials. Turkey produces about 70% of the world hazelnut production. The aim of this thesis is to reduce the thermal conductivity coefficient by adding organic waste (hazelnut shell) into clay mixture to form porosity during firing of clay bricks. Moreover, it is to maintain the similar mechanical properties by adding inorganic waste (red mud) into clay mixture. The development of a highly porous bricks with applicable mechanical strength will contribute to save energy in the building ...Daha fazlası

Design of wireless controlled robotic hand

Kızıltaş, Faruk Sanberk

Thanks to the rapid technological development, robot usage in human life increases day by day. Various kinds of robots that are designed for different tasks aim to increase the quality of human life by replacing or reducing required human power in related areas. Being able to interact robots from a distance by using wireless communication not only provide mobility and ease of use to the user but also promote the usage of robots into various areas. Considering these, this study aims to design a lower degrees of freedom robotic hand with respect to the natural anatomy of the hand and control i ...Daha fazlası

Classification of Hand Gestures Using Time-Frequency Analysis and Different Artificial Intelligence Methods

Deniz Hande Kısa

Hand gesture-based systems are one of the most effective technological advances. Surface electromyography (sEMG) is utilized as a popular input data for gesture classification with elevated accuracy and advanced control capability. In this thesis, which is based on the classification performance of Hilbert-Huang spectrum (HHS) images obtained from Hilbert Huang Transform (HHT) of the sEMG of the gestures, an evaluation of the results of artificial intelligence (AI) methods on hand gesture classification using HHS image is presented.

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

Finite Element Analysis-Based Pre-operative Planning Applications of Tooth, Tibia, and Femur Bones

Samet Çıklaçandır

Ameliyat öncesi planlama veya eğitimde, zorlu cerrahi operasyonları kolaylaştırmak için 3D modelleme ve kişiye özgü kemik modeli kullanılabilir. Bu prosedür, 3D baskı ve simülasyonların gelişmesi nedeniyle daha etkili ve uygulanabilir hale geldi. Bunun yanında, sonlu elemanlar analizi (SEA) mekanik analiz sonuçlarına yakınsayarak kemik modellerinin ve çeşitli tıbbi ekipmanların oluşturulmasını daha hızlı ve daha güvenilir hale getirebilir. Fakat, simülasyonların ve mekanik testlerin modeller üzerindeki etkisi hala tartışmalıdır. Bu sebeple bu çalışmada femur başı ve medial malleol olmak üzere ...Daha fazlası

Investigation of Manufacturing and Characterization of Radar Absorbing Hybrid Structures

Mohamed Yousef Ali Issa

Significant development of radar systems after World War II has led to studying the interaction between electromagnetic waves at radar frequencies and different materials. One perspective of these studies is to ascertain ways of decreasing reflected waves. However, the applications have not been limited only to defense applications but also to different fields where human beings are exposed to electromagnetic waves to avoid potential health effects due to exposure to electromagnetic waves. Since the discovery of radar systems, many studies have focused on electromagnetic radiation and absorbin ...Daha fazlası

Investigation of the Effects of Statistically Significant Features on the Classification of EEG-Based Motor Imagery Tasks

Murside Degirmenci

Motor imagery (MI) task classification is highly prevalent in Electroencephalography (EEG)-based Brain-Computer Interface (BCI) research area. Extremity movement task classification and finger movement classification studies are presented in this thesis. In extremity movement classification, binary-class (right hand and left hand) and multi-class (right hand, left hand, right hand, and left hand) classifications are performed using 4 different feature extraction approaches and statistically significance-based feature selection (the independent t-test, one-way ANOVA test). Firstly, time- ...Daha fazlası

Enhanced Anti-Cancer Photodynamic Activity with Photobiomodulation Therapy at Different Wavelengths

Büşra Sirek

Photodynamic therapy (PDT) is a non-invasive therapy that induces photochemical reactions for treating many diseases including cancer using the advantages of light. It is based on the interaction of light at a specific wavelength and light-sensitive chemical which does not have dark toxicity. Thus, PDT is an anticancer therapeutic modality yielding cancer cell death. As with other anticancer therapies, some drawbacks reduce or limit the efficacy of PDT. To eliminate the disadvantages resulting in increased efficacy of PDT, it is combined with other anticancer treatment methods. Together use of ...Daha fazlası