Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Author: search.filters.author.Tekin, Hüseyin CumhurPublisher: search.filters.publisher.Izmir Institute of Technology

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  • Master Thesis
    Manufacturing and Characterization of Perovskite Thin Films Using Novel Methods
    (Izmir Institute of Technology, 2020) Tekin, Hüseyin Cumhur; Sarı, Emre; Sarı, Emre; Tekin, Hüseyin Cumhur; 03.01. Department of Bioengineering; 04.04. Department of Photonics; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
    Perovskite photovoltaics is a promising technology due to its low-cost fabrication and high efficiency. Since their first demonstration in 2009, efficiencies of perovskite solar cells (PSCs) increased unprecedently fast from 3.81% to 25.2% in 10 years. The most common method for the deposition of the absorber layer of the perovskite solar cells is the spin-coating method, which is not a scalable method, and this method is an obstacle to their commercialization. Efficiencies obtained with scalable methods are currently lower than that of the spin-coating method. In this thesis, among the scalable deposition methods, a novel ultrasonic spray-coating was used by adding antisolvent vapor to the system. The antisolvent quenching technique, that is commonly used to improve the crystalline quality of the film by spin-coating was successfully adapted for ultrasonic spray coating. The interaction between diethyl ether (DE) vapor, which is used as an antisolvent, and MAPb(I(3-x)Brx)3 precursor solution (where the solvent is DMF:DMSO, 4:1) was utilized to improve the crystalline quality of the perovskite film. As a result of this interaction, the intermediate phase was observed. The transition to the intermediate phase is supported by data from characterization methods such as optical microscopy, scanning electron microscopy (SEM), X-Ray diffraction (XRD), and current-voltage measurement. Furthermore, n-i-p devices with the FTO/c-TiO2/m-TiO2/MAPb(I(1-x)Brx)3/Spiro-OMeTAD architecture were produced with different antisolvent vapors and their efficiencies was compared. It was observed that devices using DE vapor reach higher efficiencies than devices without any antisolvent vapor.
  • Master Thesis
    Detection of Febrile Illness and Its Monitoring Using Iot Technology
    (Izmir Institute of Technology, 2019) Tamur Kaya, Gamze; Özuysal, Mustafa; Tekin, Hüseyin Cumhur; Tekin, Hüseyin Cumhur; Özuysal, Mustafa; 03.01. Department of Bioengineering; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Measuring and monitoring body temperature has importance for disease diagnosis. It could also help following the course of the disease. Extensive number of body temperature monitoring applications are designed and developed. These applications could be named as healthcare applications aiming to provide convenience to the users. The Internet of Things technology is popular in healthcare applications by offering remote and real-time monitoring. In this project, a telemedicine platform facilitating the diagnosis and monitoring of febrile illnesses is designed. A user-friendly platform is implemented using software components. Message Queuing Telemetry Transport (MQTT), which is a communication protocol, is used for the communication between devices and monitoring system. A broker is used to transmit measured body temperature data from a device to the cloud server. The performance of the broker is evaluated with thousands of generated data packets. It is showed that the platform can handle data requests with a high throughput, i.e, up to 40000 packets/s. The monitoring system is designed as an interactive user interface. For this purpose, Telegram is adapted to the requirements of the platform by using an open-source library of Telegram BOT API. Hence, a user is able to access the measurement results and also control the measurements using instant messaging via Telegram interface. Moreover, this proposed platform could eliminate the use of separate healthcare applications for different diseases by using just a single instant messaging program for all different applications.
  • Master Thesis
    Development of a Cell Sorting Platform Based on Magnetic Levitation Principle
    (Izmir Institute of Technology, 2019) Yılmaz, Esra; Özçivici, Engin; Tekin, Hüseyin Cumhur; Tekin, Hüseyin Cumhur; Özçivici, Engin; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Circulating Tumor Cells (CTCs) play a vital role in cancer diagnosis, prognosis and personalized medicine. However, CTCs are extremely rare in blood (i.e., down to 1- 100 CTC per 1 mL human blood) and hard to isolate because of the heterogeneity of CTCs in biomarker expression. The current CTC separation techniques use numerous differences between cells such as size, electric charges, density and expression of cell surface markers. However, these techniques have many limitations in terms of manual sample preparation steps, inconsistent results caused by low specificity and efficiency, and increased cost. Hence, there is no standard method for isolating CTCs yet. With this study, it was aimed to fill the gap in CTC isolation by proposing a new method based on magnetic levitation principle, which has recently been demonstrated as a highly acceptable method for biological characterization of cells and monitoring of their cellular events. Short while ago, magnetic levitation technology has been used to measure cell densities at single-cell level. By using this technology, unique differences in levitation height and so in density have been identified between cancer cells and blood cells. In this study, we have been developed a new label-free microfluidic cell sorter that is based on the principles of magnetic levitation. After successfully completing this master thesis, this device can be used for rapid, low cost and label-free in-vitro diagnosis of cancer by sorting CTCs from whole blood in a high-throughput manner. The sorted cells might further be collected for downstream analysis for personalized and precision medicine
  • Master Thesis
    Fabrication of Microfluidic Devices Via 3d Printer
    (Izmir Institute of Technology, 2019) Keçili, Seren; Bulmuş Zareie, Volga; Tekin, Hüseyin Cumhur; Tekin, Hüseyin Cumhur; Bulmuş, Volga; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The purpose of this thesis is to provide easy and rapid prototyping of microfluidic devices using 3D printing technology that overcomes disadvantages of traditional fabrication techniques and also enhanced optical transparency of 3D-printed microfluidic devices fabricated using new bonding strategies. For performance analysis of 3D printer, microfluidic channels and molds having different shape and dimensions were designed and fabricated. After the fabrication process, designed and fabricated channel dimensions were compared. Structures having at least having 50 μm feature were printed successfully. For enhancing transparency of fabricated 3D structures, two different fabrication techniques were developed. In these techniques, 3D structures were bonded on glass substrates with poly (dimethylsiloxane) (PDMS) and Formlabs Clear Resin interlayers. After 3D-printed structures were put on interlayers coated glass slides, they were either remained on coated slides or transferred on new slides. Bonding between 3D structures and glass slides were provided with UV exposure for resin and with elevated temperature for PDMS interlayers. Bonding strength of fabricated channels was investigated for different thicknesses of PDMS and resin interlayers. The bright-field and fluorescence imaging properties of these channels were also analyzed. Proposed fabrication technique showed 2-fold improved bonding strength and comparable bright-field and fluorescence imaging capability with respect to traditional plasma activated PDMS-glass bonding. Furthermore, protein modified glass substrates can be integrated in 3D-printed channels using the presented fabrication technique without disturbing protein functionality. Finally, in order to design a 3D-printed micropump having membranes that can be activated with compressed air, membrane deformation was characterized with different dimension.
  • Master Thesis
    Development of a Fluidic Platform for Automated Analysis of Heavy Metals
    (Izmir Institute of Technology, 2019) Gülmez, Yekta; Bulmuş Zareie, Volga; Tekin, Hüseyin Cumhur; Tekin, Hüseyin Cumhur; Bulmuş, Volga; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Heavy metals are part of Earth’s crust and the significant problem is accumulation of them in the ground waters. They have harmful results to body even they are at low concentration. Arsenic is one of the heavy metals which cause serious health problems such as; cancer, diabetes etc. Most of the developing countries are lack of detecting arsenic amount into drinking water. Therefore, especially in Bangladesh 1 out of 100 people die due to arsenic related cancer. According to World Health Organization, the maximum arsenic concentration in the drinking water must be 10 μg/L but the concentration amount reaches 50 μg/L or more at the developing countries. However, existing methods cannot detect arsenic at this range or the ones that can detect arsenic at the standard have so high prices that developing countries cannot afford. Therefore, the aim of this project is to develop a device for arsenic detection. In this thesis, a microfluidic chip was developed, and gold nanoparticles was used to detect arsenic in samples using absorbance spectroscopy. The detection principle was designed based absorption of arsenic and then gold on thiol-modified surfaces. The different concentration of arsenic samples was injected into microfluidic chip and 1.3 mg/L arsenic concentration could be detected. Then, syringe pump was added to the system and flow applied. As a result, the developed microfluidic chip is able to detect arsenic at 2.2 μg/L.