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Computer based X-Ray imaging device design alternative using consumer electronic components

Manalp, Alpman

Yüksek Lisans | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

Medical imaging provides images of structures of the body that is not visible to human eye. It is a basic need that determines the irregularities, abnormalities, parts with different densities, spaces and foreign objects that is not supposed to be in the body. It has major importance for fast and correct diagnose. Imaging is frequently used for periodic scans for early diagnostic and follow up scans of treated patients. No matter how important it is, accessibility of the imaging devices especially digital imaging systems that provides real time images is extremely limited. There are very few of imaging device especially in co . . .untries with low income. The ratio between the number of equipment and population is so low compare to what it supposed to be. Equipment serves in very condensed and unsuited environments. Additionally, capability of maintenance and reparation are very limited. More than half of the population of the world cannot access to medical imaging facilities under current circumstances, even it is an emergency. Regardless of politic and geopolitical reasons, most important reason of this problem is lack of financial power to buy and maintain this equipment. In this study, an imaging device has been designed and a prototype has been produced using consumer electronic components. The cost of the designed system is only %0.2 of cheapest commercial alternative. Captured images have been compared with other commercial imaging equipment. It has been determined that the designed system is sensitive and capable enough to use for medical purposes Daha fazlası Daha az

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

Manalp, Alpman

Yüksek Lisans | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

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 the design of the composite structures. Es . . .pecially, in dynamical engineering systems, fundamental frequency have to be taken into account in order to prevent resonance arising from external excitations. Laminated composite materials can fulfill this requirement with an appropriate stacking sequence by using optimization methods. In this thesis, the optimum designs of non-hybrid and hybrid laminated composite plates have been investigated. The considered laminated plate is simply supported on four sides. In non-hybrid cases, fundamental frequency is taken as objective function and fiber orientation angles of the laminated composites are taken as discrete and continuous design variables. The optimization has been conducted using graphite/epoxy, glass/epoxy and flax/epoxy materials for various aspect ratios (0.2-2). Single objective optimization formulation have been used for mathematical verification of model problems. In hybrid cases, multi objective approach is considered to maximize the fundamental frequency and minimize the cost simultaneously. The design variables of the multi objective optimization problems are selected as fiber orientation angles, the number of outer layers (No) having high-stiffness and more expensive and the number of inner layers (Ni ) having low-stiffness and inexpensive. Multi objective optimization has been carried out using hybrid graphite-glass/epoxy and graphite-flax/epoxy materials for various aspect ratios (0.2-2). Ecological approach in automotive, aerospace and marine industries have stated that natural fibers (especially flax) are of great importance for their use as alternative reinforcing materials to glass fibers because of their inherent good vibration and cost xii performances. In this regard, the present study is an attempt to show the usage of flax fiber as an alternative to E-glass in interply hybrid composite structures in terms of fundamental frequency and cost. Stacking sequences design and optimization of laminated composites based on Differential Evolution (DE), Nelder Mead (NM), Random Search (RS) and Simulated Annealing (SA) algorithms are considered. The results show that the proposed optimum graphite-flax/epoxy interply composite structure give better than the result of graphite-glass/epoxy in terms of maximum fundamental frequency and minimum cost. It is also found that DE, NM and SA algorithms show superior or at least comparable performance versus Ant Colony Optimization (ACO), Simulated Annealing (SA) and Genetic Algorithm (GA) in the literature for the same laminated structure design problems Daha fazlası Daha az

Synthesis, characterizatıon and application of new organic electroactive molecules for photovoltiıc devices

Manalp, Alpman

Doktora Tezi | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

PEDOT:PSS is with its acidic property solves the indium atoms from ITO and indium atoms diffuses in active layer in an organic solar cell. This event causes an decreasing in solar cell efficiency. In the same strategy, SAM molecules can be used as hole injection layer. On the other hand MoO3 can be used as anode buffer layer. In this thesis it is wanted to make SAM molecules have to not absorb visible range of solar spectrum for the efficient harvesting of solar energy by donor molecule. Otherwise the HOMO level of SAM molecule have to be between work function of ITO and HOMO level of donor molecule. In this way SAM molecules which . . .don’t absorb the visible range of solar spectrum and with the suitable HOMO levels were designed, and applied on organic solar cell. On the other hand, while the series resistance in the solar cells to be formed with the synthesized molecules decreases according to the standard, parallel resistance increase is aimed. DSSCs were proposed instead of silicon solar cells with their easy production and low cost fabrication. The photosensitizer which is liable for the visible and near-infrared utilization of the solar light, is one of the basic components of the DSSCs. Metal free organic dyes can be thought as an alternative for the solar energy to electricity conversion in DSSCs. One of the important parameter for the dye is harvesting solar energy efficiently. If the dye absorbs all solar spectrum more energy could be harvested. Furthermore, the energy levels of dye has to be suitable with TiO2 and hole transport material. On the basis of this we designed two metal free organic dyes for DSSC, absorbing uv-visible range of solar spectrum and having proper HOMO-LUMO levels, were designed, and applied on dye sensitized solar cell Daha fazlası Daha az

Synthesis and application of the iridium semiconductor complexes for organic light emitting diodes

Manalp, Alpman

Doktora Tezi | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

Organic light emitting diodes (OLEDs) is a multi-disciplinary research area. Due to the possibility of being produced in different designs and low costs, studies on the research and development of energy efficient structures have increased. These expectations have increased so much that research on new types of molecules and device designs is increasing with the expectation that OLEDs will be more efficient than all available light sources and that almost 100% of the energy used can be converted to light. Transition metal complexes, especially Iridium(III) complexes, which make them phosphorescent due to their high quantum yield and . . . broad emission colors, have been the most widely used emission material for OLED applications. Because the materials with this property provide both singlet and triplet transitions, all excited states contribute to light emission, so the theoretical internal quantum yield of these complexes can reach 100%. In this work, 4 spiro-based ligands were synthesized by Suzuki cross-linking methodology and 8 novel Ir(III) complexes were synthesized with these ligands. The synthesized molecules were characterized by 1HNMR, 13CNMR, UV-Vis, photoluminescence (PL) and cyclic voltammetry (CV) techniques. Ir(III) complexes have been prepared functionalized as two series. The photophysical properties of the functionalization have been examined to determine the effect on the emission. It was determined that complexes with solution phase emission studies had green and orange emissions ranging from 510 to 578 nm with the effect of functionalized electron donating group (EDG) and electron withdrawing group (EWG) groups. These results showed that substituent groups are effective on the emission of complexes. The results from cyclic voltammograms show that EDG and EWG groups and complexes have different energy band intervals (Eg value). Some of the synthesized iridium complexes were made with a light emitting device (single active layer OLED, light emitting electrochemical cell, LEC device). It has been observed that these devices can operate at low voltages. LEC devices were prepared in the ITO/PEDOT:PSS/Ir(III)complex/Ag configuration. It was determined that the prepared LEC devices started to radiate at on average of 5.5 V and the highest luminance value (in C2 complex) was measured as 1107 cd/m2 Daha fazlası Daha az

New grade of thermoplastic polyurethane with high thermal conductivity and low coefficient of friction

Semiz, Seçkin

Yüksek Lisans | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

Today, thermoplastic polyurethane materials are widely used in many different applications. There are many types of thermoplastic polyurethanes which offers different mechanical and chemical properties according to application area. In addition to the existing properties, thermoplastic polyurethane materials mixed with various additives to obtain specific, targeted thermoplastic polyurethane materials in order to impart different properties to the material for application. In this study, materials of the sealing elements are approached which is one of the most important parts of the hydraulic & pneumatic systems widely used i . . .n industry. Nowadays when energy efficiency and product life become vital, it is quite important that prolongation of the sealing element life, increasing the energy efficiency and reducing maintenance requirements for hydraulic & pneumatic sealing elements sector. This study gains importance in terms of bringing the properties such as low coefficient of friction and high thermal conductivity coefficient in materials of hydraulic pneumatic sealing materials without breaking the standard physical and chemical properties of the material. Standard features expected from hydraulic & pneumatic sealing materials summarized as tensile strength, elongation at break, hardness, deformation under pressure (compression set) and wear resistance. In addition to these properties of standard materials, it envisaged that imparting low coefficient of friction to materials will reduce wearing because of friction and heat formation, imparting high thermal conductivity will facilitate transferring the heat generated from the material to the surrounding area. If these two properties are insufficient, burn spots and abrasions due to temperature increase observed in the working surfaces of the sealing elements. Herewith these problems cause leakage that is the indication of failure. By preventing these situations, the sealing elements will be able to benefit from the sector with higher energy efficiency and longer working life. Four different additive materials such as boron nitride, MoS2 ,graphite and PTFE were used at three different doses each to gain the specified properties to the thermoplastic material which is used in this study. The base material compounded with the additives was re-granulated with twin-screw extruder and after heat treatment of the materials, test plaques and sealing elements were produced with the help of plastic injection machines. xxvi FTIR, thermal conductivity coefficient, tensile, compression set, coefficient of friction and friction tests carried out to examine the properties expected to change. When all the results analyzed according to the tests performed, it has been observing that Sample 6 which has 5% PTFE acquired the targeted properties without deteriorating the existing properties. In this compounded material, the coefficient of thermal conductivity increases and the coefficient of friction decreases while the hardness, stress at 100% strain and compression set values are within acceptable limits Daha fazlası Daha az

Synthesis of imidazole derivatives and their binderless immobilization to fabric to load antibacterial properties

Mutlu, Nurgül

Yüksek Lisans | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

The compounds bonded with functional groups in textile materials carry the economical support material property. The complex and/or organic compounds with the desired properties can be immobilized into the textile materials by using the reactivity of hydroxyl groups of cellulose and the NH2 groups in wool. Most of commercially purchased silver salts show a rapid release of silver in water because of their ionic structure. For this reason, they exhibit high antibacterial activity but the short-term. N-heterocyclic carbene (NHC) complexes have the long-term antibacterial effects by releasing the silver ion into solution gradually. Rec . . .ently, the studies on the reactions about catalytic activities of silver NHC compounds have also increased. It is aimed to synthesize the light resistant, antibacterial and catalytic effective complex and also to immobilize this complex into the fabric by considering the light sensitivity of silver compounds. In the light of this information, synthesis, physical properties, and antimicrobial activities of imidazole based 1,3-disubstitue imidazolium silver (I) complexes have been targeted. The structure of synthesized compounds was determined by FTIR, NMR. The light stability of the complexes and antibacterial effectivities was investigated, then the complexes which are stable to light and exhibit antibacterial effectivity was immobilized to wool fibers with functional groups of the complexes. The immibolization was created with chemical bonding between the wool fabric and the synthesized compounds. The metal content of the immobilized complexes was analyzed by ICP and their surface characterization was identified by SEM. After the measurements of antibacterial effectivity and washing durability of immobilized complexes, color changing which is a general problem of silver compounds was measured using spectrophotometer. The antibacterial effectivities of the modified fibers were investigated by quantitative method at pre-washing and after sequence washings Daha fazlası Daha az

OPTIMUM DESIGN OF ANTI-BUCKLING BEHAVIOUR OF THE LAMINATED COMPOSITES BY DIFFERENTIAL EVOLUTION AND SIMULATED ANNEALING ALGORITHMS

Akçair, Mehmet

Yüksek Lisans | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

Laminate composites can be used quite naturally in automotive, marine, aviation and other engineering branches. Determination of buckling load capacity under in-plane composite loads of composite plates is very important for the design of composite structures. In this thesis, Differential Evolution (DE) and Simulated Annealing (SA) are utilized for optimal stacking sequence of a laminated composite plate, which is simply supported on four edges and is subjected to biaxial in-plane compressive loads. The optimization problem parameters are defined as (i) Objective function: critical buckling load factor, (ii) Constraints: sym . . .metric and balanced structure, thin plate assumption, specially orthotropic material, discrete search space, (iii) Design variables: fiber orientation angles of lamina. The laminated composite plate under consideration is 64- ply laminate made of graphite/epoxy. The fiber angles are integers varying between -90 and 90 ( 90 90 ) with different degree increments in the laminate sequence. In cases where the angle variation are continuous and discrete, the optimization results are compared. In addition, the optimization methods used in similar optimization studies in the literature and the results obtained under the thesis (based on DE and SA) are also compared. The critical buckling loads are maximized for the factors of load case and plate aspect ratio, and are compared with published results. Moreover, critical buckling load factor has been investigated for the materials Boron/Epoxy, Graphite/Epoxy, Carbon/Epoxy, Kevlar/Epoxy, S2 Glass/Epoxy, Fiberite/HyE9082A, S-Glass/Epoxy, E-Glass/Epoxy, Flax/Epoxy, E-Glass/Polyster, Alfa/Polyester and Flax/Polypropylene. As a result, it has been found that the parameters load, load ratio and plate aspect ratio are effective for optimization of the critical buckling load factor that increases buckling resistance of laminated composites. It is also observed that the DE method shows better computational performance than SA Daha fazlası Daha az

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

Kalkan, Şevket Onur

Yüksek Lisans | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

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 stages and/or textile materials that thrown . . .away after use. These waste and/or residual materials could be seen as a recycling material in the internal components of the textile sector. However, also it can be seen that the accumulation of waste textile fiber amount left over from recycling process cannot be underestimated. These textile wastes accumulation also brings up a potential material that may also be regarded as an industrial material. However, today, sufficient level of research on waste materials that shows accumulation characteristics cannot be seen to create added value in the industry. A comprehensive experimental investigation was carried out to develop especially fiber reinforced composite plaster products for construction sector by using appropriately sized and configured textile waste or residues. In this context, this experimental research includes the assessment of the use of four different types of textile wastes in the building plaster material. Especially in construction sector, the potential of evaluation of using textile fibers as fiber additive in production of lightweight construction material and production of mortar is being developed in recent years. Technical advantages of fiber additives on building materials are detailed examination subject. But also, it is not found any sufficient level of technical findings on the mechanical and the physical advantages of textile waste fibers. In this context, technical relationship between different types of fibers and mortar combination has been a special examination area by experimental analysis. In addition, textile wastes are accumulating every day in the factories of textile firms that constitute the mainstay for the Turkish economy. Companies usually under extra financial obligations in order to use, recycle or dispose those textile wastes. This thesis will have a unique value in the context of shed light on companies this seeking, besides contributing the national economy Daha fazlası Daha az

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

Kalkan, Şevket Onur

Yüksek Lisans | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

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 compare traditional and other insulation . . .materials to innovative insulation materials, figure out the pros and cons and to contribute the literature is the aim of this thesis. By starting with a wide chamber to a narrowing view and outlining the innovative insulation materials, the method used to explain in this thesis is; to create a knowledge group over lots of books, internet sites, journals, publications etc., to classify the materials per this knowledge, to outline, represent the innovative insulation materials class and to gain the reader knowledge in this subject via results, recommendations and to point out possible researches and spots which needs to be lightened in the future. To understand the thermal insulation term, the heat term is first need to be understood, it's behavior and to identify how heat loss occurs, how much of it and how should it be prevented are important topics. Air is continuously in a tend to travel from a hot region to a cold region. This ends up with a need of preventing the air escape in winter and preventing the air coming from outside in summer. Thermal insulation materials are used to minimise the passage of the air through a wall section, and these vary due to their basic properties. Each material also has a specific heat capacity. Materials with high heat capacity will store the energy and delay the warming of a room. It is also important to look from this point when selecting the material. Also, to prevent thermal bridges (cold bridge) is a key factor to avoid heat loss. These capillary gaps cause heat flow continuously and lets heat pass. Subsequently, thermal comfort term and requirements of thermal insulations values in different countries should be known and designs should be carried in accordance with these. Thermal comfort is a temperature zone where a person feels comfortable to spend time in an area. This value is higher where people spend more time whilst it is 1-2 C less in rooms like bathroom and toilet. A person should be living in between certain degrees because of human nature or will feel uncomfortable and will look for alternative solutions. Parallel to this, each country has requirements for thermal xxiv transmittance values (U-value). These values are lower in cold climates and higher in hot climates. Another topic which concerns individuals is the term also known as "energy efficiency" which states the fuel consumption needed to provide demanded temperature in a space. Again in this field, popularity of green buildings is increasing to minimise the fuel consumption and inevitably the importance of thermal insulation materials have been realised related to this. Expenses to heat the house is climbing to a disturbing rate because of heat loss and low energy efficiency even though it is a basic need. The possibility of saving 40-50% of these expenses with simple tackles shows us the importance of this sector. Known as green buildings, graded as an A class in Building Energy Ratings are expensive during construction but the expenses due to energy saving redeem itself in short periods which has been proved by lots of researches. Energy Performance Certificate; states the stamina of the house against heat by a specialist and gradation of the house's thermal condition between A-G where A is the highest and G is the lowest. A lot of country requires this certificate before selling or renting properties. Individuals can easily have a clue how much the costs might be by looking at these certificates. Further to that, after understanding these terms it will be much easier to see which of the properties are key for thermal materials and which of them are widely used. The layers in the wall section like paint, plaster, thermal insulation material, brick or block layer are directly involved in thermal transmittance according to their thickness and thermal properties. For example, brick stores heat because of being thick and it's specific heat capacity being high. Another important definition is thermal conductivity value. Each material has a unique thermal conductivity value and thermal transmittance changes due to section thickness and thermal conductivity. It is possible to see the material thermal conductivity value on the label of products. The primary materials widely used around the world are EPS, XPS, rock wool, fiberglass, polyurethane, panel and foam types of these. They are also called as traditional insulation materials. They are satisfying both as costly and thermally at the present, but required thermal transmittance values are likely to decrease against the global warming and cooling, and this will end up with thicker usage of present materials or usage of alternative materials. In this study, traditional, organic, innovative and textile thermal insulation materials are classified and innovative insulation materials are outlined. Nevertheless, innovative insulation materials have been discovered to tackle the problem mentioned above as result of researches. For example, transparent insulation materials are widely used in glass facade buildings. Again being in this class Vacuum insulation panels have up to 10 times better thermal properties than traditional materials. Numeric examples are also given in this study. Also gas filled panels, naturally aggregated materials and materials made of textile wastes are being subject to competitive researches. It is possible to make some conclusions in the light of all above. In consequence of these conclusions, there are areas where researches should be carried out and points to focus on to show progress. Particularly, two materials could be called as unique. Yet they are too expensive and they also have some lacks. For example, the service life of vacuum panels are not as long as demanded. They are likely to keep same thermal properties for 30-50 years and subsequently unpredictible values are likely to occur. It is also a necessaty to teach working force how to apply such materials. xxv Hence, generally daily payed workforce would cost more than normal to apply these already expensive materials which obstructs these materials being widely used. Turkey's position in energy efficiency has also been evaluated in this research and been shared as a summary. Opinions has been outlined about what point it could be if being used innovative insulation materials by comparing to other countries. This research also referes to how Turkey can jump ahead in energy efficiency (which is way behind other European Countries) by applying correct policies, but that users should be encouraged to use certain materials or they will continue using materials they think are the most economic ones Daha fazlası Daha az

Simulation and design of a glider swarm robotics platform

Gül, Kasım

Yüksek Lisans | 2017 | İzmir Katip Çelebi Üniversitesi Fen Bilimleri Enstitüsü

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 designed five identical mobile robots that in . . .teract with each other and the simulation software at PC through RF connection. PC runs a Glider simulation simultaneously while robots play “Game of Life” on the grid. Presented model is a self-organized and a self-driven mechanism. The base platform used is a lattice of squared cells, but the shape of cells can be hexagonal and other shapes as well. Each cell can exist in 2 or more different states (not simultaneoulsy). Most basically ON/OFF states of bright LEDs at the top of each robot is controlled as an indicator to show dead/alive modes of the robots. We expect our robots to move on the lattice base as in Glider form and keep their formation patterns after each step. Mobile robots are based on Arduino Nano boards. NRF24L01 RF modules used for communication. ULN2803 IC is used to drive two stepper motors (28BJY-48). Each robot is powered with a pack of 4 AA batteries. Each member robot will keep its track and location information and inform the main PC simulation software. After each robot completes its action, the simulation software moves to the next pattern of Glider and the LEDs of robots will be turned ON (Live Mode). Atmel328P based board with a NRF24L01 RF module establishes the real time communication between Glider robots and the PC. Main module transfers required pattern data to each individual Glider robot and receives a confirmation of correct data transmission from each robot. After each robot gets its required data, then the main module updates the information of simulation software that runs on the PC. It is possible to observe the pattern evolution of Glider robots on the simulation software. Processing programming language is used to create the simulation software. xvi With all these simple and commonly found parts, each robot was produced with quite a cheap and simple way. Thus, the total number of robots can be increased to more than 5 and different CA models can be realized with this platform. Some improvements should be done on our system such as including another NRF24L01 module for each 6 mobile robots due to available channel number restriction of RF module used. Atmel2560 based board can provide much more communication capability for crowder Swarms with additional RF modules. Another future development of the system should be to include a path finding algorithm into simulation and create “maze solving” or “target searching” Swarm group with much better performance. This method will allow to conclude results in much shorter times and with much less effort Daha fazlası Daha az

6698 sayılı Kişisel Verilerin Korunması Kanunu kapsamında yükümlülüklerimiz ve çerez politikamız hakkında bilgi sahibi olmak için alttaki bağlantıyı kullanabilirsiniz.

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