Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Development of a New Infrared Spectroscopic Method Based on Multivariate Calibration for the Determination of Aluminum and Magnesium Oxid Thickness on Aluminum Foil and Sheets Surfaces(İzmir Institute of Technology, 2016) Meşe, Ayten Ekin; Özdemir, DurmuşSurface oxidation is a general problem for certain industrial applications such as coating and painting of the finished rolled products. A detailed understanding for the oxide growth mechanism as well as the development of a simple analytical method to measure this oxide thickness is very important in aluminum rolling industry and this study aims to develop a spectroscopic method to determine the oxide thicknesses on the surface of the aluminum by using multivariate calibration and infrared spectroscopy. Two main series of different aluminum alloys (3005 and 3003BZ) were selected in this study to develop a proposed methodology which is based on the combination of Fourier Transform Infrared Spectroscopy (FTIR) with Grazing Angle ATR accessory and chemometrics multivariate calibration techniques. In order to obtain oxide thickness values, X-ray Photoelectron Spectroscopy (XPS) was used and aluminum oxide (Al2O3) and magnesium oxide (MgO) thicknesses determinations were carried out by two different multivariate calibration models which are Genetic Inverse Least Squares (GILS) and Genetic Partial Least Squares (GPLS). These models were able to predict Al2O3 and MgO thicknesses using FTIR that is faster, easier and cheaper to operate as well as from XPS. The correlation coefficients of XPS reference oxide thickness values versus FTIR-GATR based GILS and GPLS predicted values were better than 0.919 in range of 0 to 25 nanometers for Al2O3 and 0 to 35 nm for MgO. These results suggest that grazing angle FTIR-ATR spectroscopy may offer a simple and nondestructive alternative for quick determination of oxide layer thickness.Master Thesis Bim Execution Process of Construction Companies for Building Projects(İzmir Institute of Technology, 2016) Gerçek, Bilge; İlal, Mustafa Emre; Günaydın, Hüsnü Murat; Tokdemir, Onur BehzatBuilding Information Modeling (BIM) is an emerging concept in architecture, engineering and construction (AEC) industry promising to replace traditional 2D based construction documentation and management procedures and to reduce rework and cost in project execution. The level of information that could be assigned to building objects in BIM technologies could provide vast amounts of benefits to construction projects throughout projects’ life-cycle. Implementation of BIM, however, requires strategic planning to enable achieving these potential benefits. Industry-wide and organizational implementation guidelines and standards have been published around the world either to encourage organizations to adopt BIM or to present the minimum requirements to be followed where BIM implementation is a statutory obligation. In contrast, BIM implementation and/or deliverables has not been mandated by government or organizations yet in Turkey, therefore organizations which plan to adopt BIM processes have to develop their own implementation plans. The purpose of this study is to provide guidance in BIM implementation for construction companies particularly during the construction phase of the building projects. BIM standards and guidelines, and studies related to BIM implementation have been reviewed and important aspects of implementation have been identified. A case study of BIM implementation at a large construction company in Turkey to conduct quantity takeoff and cost estimation are presented and unique challenges of BIM implementation in Turkish AEC industry are discussed.Master Thesis Solid Phase Extraction of Ibuprofen in Waters With Molecularly Imprinted Polymers Prior To Hplc-Dad Determination(İzmir Institute of Technology, 2016) Ölçer, Yekta Arya; Eroğlu, Ahmet EminEndocrine disrupting compounds (EDCs) attract great attention worldwide due to their undesired effects on human health. Ibuprofen, an example of endocrine disrupters, is a nonsteroidal anti-inflammatory drug (NSAID). In this study, highly selective molecularly imprinted polymers (MIPs) with different morphologies (as monolith and microspherical beads) were synthesized by bulk and precipitation polymerization strategies. MIPs were prepared by using acetonitrile as porogen, methacrylic acid (MAA) as monomer, trimethylolpropane trimethacrylate (TRIM) as crosslinker and the analyte, ibuprofen, as the template. MIPs revealed higher affinity to the template molecule as compared with non-imprinted polymers (NIPs). The MIP prepared by precipitation polymerization was decided to be used as the primary solid phase extraction (SPE) sorbent due to its higher binding capacity towards ibuprofen compared to the MIP prepared by bulk polymerization. Selectivity of MIP to ibuprofen was examined in the presence of structurally related compounds. In this study, a molecular imprinting solid phase extraction (MISPE) methodology was proposed for determination of ibuprofen prior to HPLC-DAD analysis. For this purpose, critical experimental parameters of MISPE method were optimized and determined as follows; solution pH of 8.0, sorbent amount of 25.0 mg for 10.0 mL of 1.0 mgL-1 working solution, sorption time of 30 min and MeOH:H2O (acetic acid, pH 3.0) ratio of 80:20 as desorption solution. The accuracy of the proposed methodology was verified with spike recovery tests for tap and drinking waters and overall recovery was found as 97.4 (± 0.3) for n=3.Master Thesis Fabrication of Thin Layer Polymer-Based Biointerphase for Biosensing Application(İzmir Institute of Technology, 2016) Yücel, Müge; Yıldız, Ümit HakanThis study aims to fabricate polymer-carbon nanotube composite as a bioelectronic interface for sensing volatile organic compounds (VOCs) in exhaled breath. Sensor platform is made of two layers i) polymeric membranes and ii) conducting layer. Poly(vinylidene fluoride) (PVDF), polystyrene (PS), and poly(methyl methacrylate) (PMMA) are selected as model polymers that are processed by electrospinning to utilize polymeric membranes. Multi-walled carbon nanotubes (MWCNTs) are used to fabricate conducting layer on top of PVDF, PS, PMMA polymer membranes. Aqueous solution of well-dispersed MWCNTs are obtained by several purification and filtration steps and conductivity of working MWCNT solution is adjusted about 120 μS/cm for whole study. This solution is further used to impregnate PVDF, PS, PMMA membrane. The PVDF-MWCNT, PS-MWCNT and PMMA-MWCNT sensor platforms are tested by electrochemical station that recording electrical resistivity change by time. All sensors platforms, made of three polymeric membranes-MWCNT, are found to be a responsive upon applying the toluene and acetone vapor. The sensing mechanism is hypothesized as the adsorption of VOCs onto the conducting CNT layer blocking electron stream on CNT network and causing resistivity change. The sensitivity of PVDF-MWCNT sensing platform is exceedingly higher with respect to other two candidates due to solvent vapor- polymeric membrane interactions. This contribution changes sensor platform characteristics and make them quite sensitive to trace amount of VOCs. Acetone and toluene are detected from ppm to ppb range and reproducible responses are recorded. As a result, acetone and toluene, biomarkers of diabetes and lung cancer, can be differentiated with produced sensor.Master Thesis Energy and Environmental Performance Based Decision Support Process for Early Design Stage of Residential Buildings(İzmir Institute of Technology, 2016) Gerçek, Mümine; Durmuş Arsan, ZeynepDeficiencies in systematic approaches for design decision support to increase energy and environmental performance of buildings in Turkey are projected as the major problem of this study. Rare usage of computational methods for evaluating and improving building performance, need for informational assistance in design, as well as lack of interaction between systematic knowledge and building practice are the secondary problems. This thesis mainly aims to test usability of the decision support process assisting architects in early design stages of residential buildings. Assessing the uncertainties in building performance caused by design parameters and climate change, in terms of determining the most significant parameters on annual energy consumption for heating, cooling and operational CO2 emissions in hot humid climatic region of Turkey is the significant objective of the study. The relation between input parameters and building performance indicators is examined by the uncertainty and global sensitivity analyses for a residential building in İzmir, Turkey. The process is supported by usability testing held with the architect in practice. The results indicate that, the sensitivity between input and output parameters changes according to the projected weather conditions and different floors of the building. The SHGC of windows on south-west, north-east facades, and window U values are the most effective parameters on energy and environmental performance. The proposed decision support process is approved to be applicable for early design stages of the selected building, and helps creating consciousness about the importance of systematic design decision approach for the building professional.Master Thesis Copper-Catalyzed Synthesis of Benzo-Bimane Derivatives(İzmir Institute of Technology, 2016) Zeybek, Hüseyin; Emrullahoğlu, Mustafa1,5-Diazabicyclo[3.3.0]octadienediones (shortly 9,10-dioxabimanes or "bimanes") are small heterocyclic structures which have important chemical, photochemical and photophysical properties. There are two existing structural isomers for bimane compounds ("syn" and "anti"). The syn-isomers have strong UV absorption properties and high quantum yields and are highly fluorescent. Bimane compounds are widely used for fluorescent labelling in biological systems because of their high photo-stability and bio-compatibility. Despite their unique properties, there is very few examples of study in literature. Because of synthetic difficulties of literature examples and their requirements such as hazardous chemicals, new methodologies are in high demand. In this study, new methods utilising metal catalysis for the effective synthesis of bimane compounds have been developed. Bimanes, which in the literature are synthesised with extreme difficulties and low yields, were synthesised in this work through simple and efficient protocols that employ metal, ligand and base. We further investigated the photophysical properties for all newly synthesized bimane derivatives. In the course of thesis study, a new and efficient method have been developed and optimised for the facile synthesis of benzo-bimane compound via the copper(I) catalyzed intramolecular C-N bond formation reaction. Moreover, with the aid of this new methodology, various analogues of benzo-bimane compound were synthesized in moderate to good yields under mild reaction conditions . Also, photophysical properties of benzo-bimanes were investigated carefully.Master Thesis Characterization of Antioxidant Properties for Dried Organic Fruits in Turkish Market and Development of Novel Strategies To Increase Their Potential Health Benefits(İzmir Institute of Technology, 2013) Dervişoğlu, Gökhan; Yemenicioğlu, AhmetIn this thesis antioxidant parameters including trolox equivalent antioxidant capacity (TEAC) and total phenolics (TPC) and flavonoid (TFC) contents of major organic dried fruits (raisins, figs, prunes and apricots) produced in Turkey have been determined to understand the bioactive potential of these products. Moreover, a novel method based on controlled rehydration of specified dried fruits in phenolic extracts has been developed to boost the phenolic content and antioxidant activity of dried fruits with low bioactivity and potential health benefits. The TEAC, TPC and TFC of sun dried fruits varied between 35.7 and 74.1 μmol trolox/g (d.w.), 1762 and 4062 μg gallic acid/g (d.w.) and 830 and 2559 μg catechin/g (d.w.), respectively. The TEAC and TPC of prunes were 1.7 to 2.3 fold higher than those for apricots, raisins and figs which showed quite similar TEAC and TPC values. On the other hand, the TFC of prunes and figs were similar and 1.7 to 3 fold higher than those of raisins and apricots. The rehydration studies with raisins conducted in different concentrations (0.5% or 1% (w/w)) of green tea extract (GTE) and walnut shell extract (WSE) at room temperature until reaching of final moisture content of 38.73 % (w/w) showed the possibility of increasing TEAC, TPF and TPC of raisins 1.6-1.8 fold. Similar rehydration strategy applied to figs, prunes and apricots in 1% GTE to bring their moisture content to 39.83, 36.97 and 43.81 % respectively, caused 1.1-1.6 fold increase in TEAC, TPC and TFC of these dried fruits. This work clearly showed the considerably higher bioactive potential of organic dried prunes than organic dried raisins, figs and apricots. However, the application of controlled rehydration process developed in this work enables increasing antioxidant potential and phenolic contents of figs, raisins and apricots to the level of prunes.Master Thesis Multivariate Statistical Optimization of Enzyme Immobilization Onto Solid Matrix Using Central Composite Design(İzmir Institute of Technology, 2013) Arpakcı, Tuğba; Özdemir, DurmuşIn recent years, scientist have been used alternative technology in order to increase enzyme stability and also reduce the cost of production of enzyme. Immobilization methods have attracted the attention of scientists due to its advantages in comparison with soluble enzyme or other methods. Immobilization process can be affected by many factors for this reason it is important to optimize the effective factors in order to enhance success of this process. In preliminary studies, Bradford protein assay was used for determination of protein concentration. In order to increase sensitivity and accuracy of this assay, Bradford protein assay was combined with a multivariate calibration methods. Genetic Inverse Least Squares (GILS) and Partial Least Squares (PLS) were used for multivariate calibration. Calibration model was constructed for various concentration of Bovine Serum Albumin (BSA). Standard Error of Calibration (SEC) and Standard Error of Prediction (SEP) were calculated and results of multivariate calibration method were compared with univariate calibration methods and each other. In this study, the bovine serum albumin immobilization studies were carried out. The bovine serum albumin was immobilized on chitosan nanoparticles and effective factors such as chitosan concentration, immobilization time, pH and temperature were optimized by using central composite design (CCD). Central composite design is used to investigate interaction between these parameters and to find the optimum values of effective factors.Master Thesis Development of Chromatographic and Moleculer Spetroscopic Multivariate Chemometric Models for the Geographical Classification of Olive Oils(İzmir Institute of Technology, 2013) Çelik, Deniz; Özdemir, DurmuşOlive oil is a fat obtained from the olive (the fruit of Olea europaea; family Oleaceae), a traditional tree crop of the Mediterranean Basin. The oil is produced by grinding whole olives and extracting the oil by mechanical or chemical means. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps. The classification of olive based on geographical origin is of great interest since the quality of olive oil depends on its chemical composition and geographical origin. In this study, it is aimed to develop classification models using elemental and molecular composition of olive oil samples via chromatographic method and molecular spectrometry. For this purpose, olive oil samples from diffirent regions of Turkey (Manisa and Bursa) were collected from producers and they were scanned with Fourier Transform Infrared spectrometer equiped with attenuated total reflectance (FTIR-ATR) accesory, and Gas Chromatography (GC), High Performance Liquid Chromatography (HPLC). Afterwards, any clustering of samples based on their regions was investigated using principal component analysis (PCA) and hierarchical cluster analysis (HCA). In conclusion, although molecular spectrometry is more advantageous for the classification of olive oil samples in the case of saving time, saving chemicals and ease of usage, chromatography gave better classification results based on geograpical origin compared to results obtained with molecular spectrometry.Master Thesis Collaboration in architectural design competitions(İzmir Institute of Technology, 2013) Erbil, Livanur; Doğan, FehmiThis study investigates design collaboration with reference to convergent and divergent idea generation processes, conceptual, spatial, temporal and technological barriers, and roles and relationships in architectural design teams entering a design competition. Study of design teams offer a unique opportunity to investigate how creativity is fostered through collaborative work. While views of creativity often relate creativity to individual originality, collaboration requires different designers to work together towards one common design idea and consider as many different ideas as possible. In collaborative design, it would be easier to offer a variety of ideas but equally difficult to establish a consensus on a single idea. To investigate the role of convergent and divergent thinking in the design process, first, 30 professional architects, who participated in competitions as a team, were interviewed via phone. Phone interviews were analyzed thematically to investigate how teams came together and how team participants overcame spatial, temporal, conceptual, and technological barriers. Convergent and divergent idea generation phases were analyzed to understand how team participants generate multiple ideas and converge on one single issue. Second, three groups of architecture students, who participated in competitions as a team, were interviewed. Interviews were analyzed thematically to investigate how teams overcame spatial, temporal, conceptual, and technological barriers. It is concluded that barriers and roles of participants in design collaboration interact with convergent and divergent concept generation. Keywords: Collaboration; Architecture Competitions; Design Process; Design Cognition