Master Tezleri

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Acoustic indoor localization employing code division multiple access
(Izmir Institute of Technology, 2010) Sertatıl, Cem; Altınkaya, Mustafa Aziz
Indoor localization becomes a demand that comes into prominence day by day. Although extensively used outdoor location systems have been proposed, they can not operate in indoor applications. Hence new investigations have been carried on for accurate indoor localization in the last decade. In this thesis, a new indoor location system, that aims to locate an entity within an accuracy of about 2 cm using ordinary and inexpensive off-the-shelf devices, has been proposed and an implementation has been applied to evaluate the system performance. Therefore, time of arrival measurements of acoustic signals, which are binary phase shift keying modulated Gold code sequences using direct sequence spread spectrum technique, are done. Direct sequence-code division multiple access is applied to perform simultaneous accurate distance measurements and provides immunity to noise and interference. Two methods have been proposed for the location estimation. The first method takes the average of four location estimates obtained by trilateration technique. In the second method, only a single robust position estimate is obtained using three distances while the least reliable fourth distance measurement is not taken into account. The system performance is evaluated at positions from two height levels using two sets of variables determined by experimental results. The precision distributions in the work area and the precision versus accuracy plots depict the system performance for different sets of variables. The proposed system provides location estimates of better than 2 cm accuracy within 99% precision. Eventually, created graphical user interface provides a user friendly environment to adjust the parameters.
Analysing the encrypted search algorithms on encrypted data
(Izmir Institute of Technology, 2018-07) Tekin, Leyla; Şahin, Serap
In this thesis, we study the static and dynamic Searchable Symmetric Encryption (SSE) schemes (Cash et al. (2014), Kamara and Moataz (2017)). We present different approaches for secure single- and multi-keyword ranked searches, that are: Sorted, OPEBased, Paillier-Based, Embedded, and Matrix-Based. We extend the base schemes according to these approaches so that the matching documents of a search query are ranked by a relevance score calculation technique like term frequency (tf), term frequency-inverse document frequency (tf-idf) or keyword frequency, depending on the characteristics of the scheme. For this, the existing structures of the schemes are modified since they cannot be directly used for ranked searches. Therefore, the ranking facility is added to them. Further, Matrix-Based Approach is a new hybrid approach that is based on an updated structure of the static scheme (Cash et al. (2014)) and fills a matrix to rank the relevant documents for a search keyword, as in the work (Ibrahim et al. (2012)), however, computing the matrix is totally different from their work.
Artificial neural networks model for air quality in the region of Izmir
(Izmir Institute of Technology, 2002) Birgili, Savaş; Tayfur, Gökmen
In this study, a systematic approach to the development of the artificial neural networks based forecasting model is presented. S02, and dust values are predicted with different topologies, inputs and transfer functions. Temperature and wind speed values are used as input parameters for the models. The back-propagation learning algorithm is used to train the networks. R 2 (correlation coefficient), and daily average errors are employed to investigate the accuracy of the networks. MATLAB 6 neural network toolbox is used for this study. The study results indicate that the neural networks are able to make accurate predictions even with the limited number of parameters. Results also show that increasing the topology of the network and number of the inputs, increases the accuracy of the network. Best results for the S02 forecasting are obtained with the network with two hidden layers, hyperbolic tangent function as transfer function and three input variables (R2 was found as 0,94 and daily average error was found as 3,6 j..lg/m3).The most accurate results for the dust forecasting are also obtained with the network with two hidden layer, hyperbolic tangent function as transfer function and three input variables (R2 was found as 0,92 and daily average error was found as 3,64 j..lg/m3).S02 and dust predictions using their last seven days values as an input are also studied, and R2 is calculated as 0,94 and daily average error is calculated as 4,03 Jlg/m3 for S02 prediction and R2 is calculated as 0,93 and daily average error is calculated as 4,32 Jlg/m3 for dust prediction and these results show that the neural network can make accurate predictions.
An assessment of spatial relationship between lung cancer incidence rate and quality of urban life: Izmir case
(Izmir Institute of Technology, 2013) Özkan, Sevim Pelin; Saygın, Mustafa Ömür
The study assesses spatial clusters of lung cancer incidences within Izmir province on the basis of districts and also neighborhood using an objective sets of quality of life indicators. Lung cancer data, approximately 18.000 cases, were acquired from the Izmir Cancer Registry Center (ICRC) between the years of 1992-2007. Cases have been confirmed in terms of accuracy by World Health Organization (WHO). As objective indicator data, point source air pollution data acquired from the Izmir Metropolitan Municipality database between the years of 1993-2007. Besides, socio-economic statistics data were obtained from Turkish Statistical Institute (TSI) regional indicators (2000,2007) and Izmir Metropolitan Municipality city health profile (2007). The datasets were used to determine whether there is a significant spatial relationship between cancer case density and environmental contamination. This thesis uses spatial statistical models and Geographical Information System (GIS) techniques to analyze population-based cancer incidence rate. Additionally, Age Standardized Incidence (ASR) of the lung cancer was calculated. Spatial autocorrelation technique was performed to investigate local distribution of lung cancer. Results of the study suggest that spatial clusters of lung cancer were detected in geographic locations with low level environmental quality and high level socio-economic profile. Then, the results are discussed in terms of life quality and environmental quality of Izmir. The results of this study are useful for interdisciplinary researchers, epidemiological studies, policymakers and governmental agencies in terms of health and environmental assessment, regulation and control of spatial strategies.
Assessment of wood laminated material for housing production
(Izmir Institute of Technology, 2019-07) Balkan, Selçuk; İnceköse, Ülkü
Today, laminated wood material is used in different types of structures. In many countries such as our country, as well as countries where this usage is intense, laminated wood material is not preferred in housing production yet. Although it seems that reinforced concrete structures have replaced wooden structures today, environmentally sensitive approaches expressed with concepts such as sustainability, ecological balance and repeatability have enabled the reuse of wood material. In this study, the properties of laminated wood technology, which is predicted to be an alternative technology to conventional construction technologies, are evaluated. With this assessment, laminated wood technology could be an alternative structure production technology in our country. At the beginning of the study, wood materials, wood damaging factors, composite wood materials, the use of wood in residential production and the use of laminated wood in residential production were examined under four main headings. The properties of wood materials and laminated wood materials were examined in detail and the methods, advantages and disadvantages of these materials were determined. This study is detailed on the structure of JZ House which was designed and built by architect Serhat AKBAY in Antalya with laminated wood technology. The laminated wooden parts produced for the building were examined based on scientific data on the design process, static resistance of the building, fire resistance, sustainability, environmental and human health contributions. With the evaluation, it is aimed to increase the preference of wooden structures constructed with developing wood technology.
B and Se transport modeling in saturated/unsaturated zones
(Izmir Institute of Technology, 2002-09) Yüreklitürk, O. Emin; Tayfur, Gökmen
There has been renewed interest in the application of models to the transport of non-point source pollutants. However, very little work has been done to evaluate the performance of a functional transient-state model for the transport of a reactive solute over an extensive study period. This research consists of mathematical modeling to simulate water flow, boron and selenium transport through soil in tile-drained croplands.For Boron part a mathematical model was developed to simulate non-conservative boron transport. The dynamic two-dimensional finite element model simulates water flow and boron transport in saturated-unsaturated soil system, including boron sorption and boron uptake by root-water extraction. Two different models have been employed for the sorption of boron. Similarly, for selenium part a finite element model is developed to simulate species of selenium transport in two dimensions in saturated/unsaturated zones. The model considers water, selenate, selenite and selenomethionine uptake by plants. It also considers oxidation/reduction, volatilization, and chemical and biological transformations of selenate, selenite, and selenomethionine. Comparison of boron transport model results with observed data is satisfactory. The model employed with Langmuir isotherm was found to give slightly better simulation results when compared with the model employed with Freundlich. The sensitivity analysis results indicate that the irrigation scheduling and the irrigation water quality are very important parameters for boron accumulation in the soil. Also the adsorption isotherm parameters, which reflect us the soil properties, are found to be important for the boron movement in the soil. Comparison of selenium transport model with observed data is not quite satisfactory in accuracy when compared with the model for boron transport. This may be the result of the complexity of the mechanisms affecting the selenium transport in soil. There are too many parameters, and due to the errors depending on the parameters, the total error for the estimation of the total selenium increases.
B-galactosidase of kluyveromyces lactis: Immobilization, characterization and hydrolysis behavior of enzyme
(Izmir Institute of Technology, 2008) Çabuk, Burcu; Harsa, Hayriye Şebnem
B-galactosidase (lactase) enzyme is of great industrial interest, since it can be used to solve problems associated with whey disposal and lactose crystallization in sweetened and frozen dairy products such as ice cream. All over the world, many people suffer from lactose intolerance and lactase preparations are used as supplements for these persons. B-galactosidase is also used to produce prebiotics since this enzyme hydrolyses lactose into galactooligosaccharides. Immobilized B-galactosidase preparations are preferred in many processes because they can be recycled and maintain their activities for a long time without loosing their chemical stability.Novel cross-linked chitosan-hydroxyapatite composite support has beenprepared, lactase from Kluyveromyces lactis was immobilized onto these beads. Lactase immobilization mechanism and effect of factors such as initial glutaraldehyde concentration, temperature, pH, initial lactase concentration, solid-liquid ratio on immobilzation mechanism were studied.Optimum cross-linking was obtained at the glutaraldehyde concentration of 100 mg/L. The optimum values of temperature, pH and solid/liquid ratio on lactase/HAChitosan were found to be 200C, pH 7.5 and 0.3g/ml Vg/Vl, respectively. The pH and thermal stabilities of free and immobilized enzymes were also investigated and it was observed that the relative activity remained above 83.2% within pH 6-7.5 and maximum activity yield was obtained at 370C for free and all immobilized enzymes. The Michaelis constant Km and Vmax of immobilized and free enzyme on chitosanhydroxyapatite composite beads were found to be 9.5 mM and Vm 454.5 .mol ONP min.1 mg.1 protein and 1.011 mM and 1098.9 .mol ONP min.1 mg.1 protein, respectively.
Biofuels production using canola oil over heterogeneous catalysts
(Izmir Institute of Technology, 2017-12) Özdoğru, Bertan; Şeker, Erol
The goal of this study was to investigate the activity of Ni loaded on Al2O3-SiO2 supports prepared with different acids for the production of biofuel grade compounds while using canola oil as our feedstock. While keeping the reaction conditions constant, catalyst preparation parameters such as aluminum concentration, nickel concentration, calcination temperature, and acid types investigated with statistical methods by constructing Box Behnken design using three continuous parameters with two levels and one categorical parameter with three level. Responses considered in this study were aldehyde, ester, organic acid and other compound yields calculated from the GC-MS analysis. After ANOVA analysis, empirical models calculated from this analysis used to optimize the catalyst preparation parameters. Three catalysts, one for each acid type, selected to investigate the validity of our model. Analysis did on these catalysts have shown that both 0% Ni/25% Al2O3-75% SiO2 w/H2SO4 at 900oC and 20% Ni/75% Al2O3-25% SiO2 w/H3PO4 at 900oC catalysts gave good ester yields with good organic acid utilization. 20% Ni/75% Al2O3-25% SiO2 w/H3PO4 at 900oC catalyst was exceptional in ester selectivity aspect while 0% Ni/25% Al2O3-75% SiO2 w/H2SO4 at 900oC catalyst was in organic acid utilization aspect. Presence of aluminum phosphate crystal phase observed with XRD resulted in 20% Ni/75% Al2O3-25% SiO2 w/H3PO4 at 900oC catalyst having the highest selectivity towards ester production. Combination of weak and strong acid sites increased the organic acid selectivity while lowering the selectivity towards esters for 0% Ni/25% Al2O3-75% SiO2 w/H2SO4 at 900oC catalyst. From the low organic acid utilization observed with 10% Ni/25% Al2O3-75% SiO2 w/HNO3 at 500oC and, 10% Ni/50% Al2O3-50% SiO2 w/H2SO4 at 700oC catalysts which had high amounts of weak acid sites, it could be said that organic acids can only be reacted over strong acid sites.
Chemical characterization of olive oils from Karaburun Peninsula
(Izmir Institute of Technology, 2014-07) Uncu, Oğuz; Özen, Fatma Banu
Chemical characteristics of olive oils produced from Erkence olive variety that is mainly grown around Karaburun Peninsula of İzmir have not been investigated thoroughly although this variety has high oil content and ripens earlier compared to other olive types. Identifying the chemical characteristics of olive oils could be useful to obtain geographical indication labelling for olive oils produced from this variety. Aim of this study is to determine some important chemical characteristics of olive oils from Erkence olive variety produced in Karaburun region and to investigate the differences in olive oils that come from various parts of the Peninsula using chemometric techniques as principal component analysis (PCA) and partial least square (PLS) regression. For this purpose, total phenolic content, fatty acid profile, phenolic profile, total carotene and chlorophyll contents and oxidative stability of 64 olive oils were determined. FTIR spectra for these oils were also evaluated. According to PCA results, classification with respect to geographical origin was relatively more successful with FTIR analysis while phenolic and fatty acid profiles did not result very satisfactory separation between regions. Moreover, FTIR spectra and various chemical parameters were used to predict oxidative stability of all olive oil samples. Oxidative stability was predicted successfully from IR spectra whereas prediction from chemical parameters was not that successful. IR spectra were also used to predict various chemical parameters. As a result of PLS regression; chlorophyll and carotenoid, some individual phenolic components (pcoumaric, hydroxtyrosol) and some major fatty acids (oleic, linoleic and palmitic) were predicted.
Classification of Turkish virgin olive oils based on their phenolic profiles
(Izmir Institute of Technology, 2008) Ocakoğlu, Derya; Tokatlı, Figen
Virgin olive oil is different from other plant oils with its high phenolic content. The resistance to oxidation and the protection against some diseases has been linked to these components of olive oil. The sensorial characteristic of extra virgin olive oil is also related to its phenolic compounds.In this work, it is aimed to determine the phenolic profiles of Turkish olive oils, which have high economic value for Turkey. Phenolic profiles of monovarietal extra virgin olive oil samples extracted from six dominant and economically important Turkish olive cultivars (memecik, erkence, domat, nizip-yaglik, gemlik, ayvalik) and commercial extra virgin olive oil samples from two different areas (south and north) of the Aegean coast were determined for 2005 and 2006 harvest years. Total phenol contents, oxidative stabilities and chromatic ordinates as colour parameters were also measured. The effect of cultivar, geographical area and harvest year on phenolic profiles of olive oils was investigated. Multivariate data were subjected to principal component and partial least square-discriminant analyses.Typical phenolic substances of extra virgin olive oils from different variety and regions are; p-coumaric acid, cinnamic acid & apigenin for memecik, erkence oils and also for oils of south Aegean; vanillin & syringic acid for ayvalik, gemlik and also for oils of north Aegean. Domat oils were characterized by their relatively high content of oleuropein aglycon. Nizip oils were separated by their 4-hydroxyphenyl acetic acid content, which was determined in very low amounts or none in other olive oils. It was observed that harvest year strongly affected the phenolic profiles of olive oils. In addition, phenolic composition was found to be useful in discriminating the olive oils from different variety and geographical area.
Classification of virgin olive oils from different olive varieties and geographical regions by electronic nose and detection of adulteration
(Izmir Institute of Technology, 2008) Kadiroğlu, Pınar; Korel, Figen
Extra virgin olive oils produced from fresh and healthy olive fruits have a delicate and unique flavor that makes them highly appreciated by consumers. Their taste and aroma are closely related to volatile and non-volatile compounds and determined by chromatographic and sensory analyses. However, these methods are expensive and time consuming to be used routinely in food industry. Electronic nose that can mimic the human sense of smell and provide low-cost and rapid sensory information is a new approach allowing the discrimination of aroma fingerprints of oils. In this study, the aroma fingerprints of Turkish extra virgin olive oils produced from various olive varieties (Ayvalık, Gemlik, Memecik, Erkence, Domat and Nizip) and Ayvalık and Gemlik olive varieties growing in two different regions of West Turkey (İzmir and Edremit) and the commercial extra virgin olive oils obtained from TarisÌ§ Olive and Olive Oil Agricultural Sales Cooperatives Union during two consecutive harvest years were determined by an electronic nose. In addition, the electronic nose was proposed for the detection of adulteration of these oils with monovarietal olive oils and with other edible oils such as sunflower, corn, soybean and hazelnut oils. The data were analyzed using chemometric methods by soft independent modeling of class analogy (SIMCA) software. As a conclusion, it was found that the electronic nose could provide good separation on some of the varieties and geographical regions. The electronic nose has been able to differentiate adulterated and non-adulterated extra virgin olive oils at higher than 10 % adulteration level successfully.
Comparison of dipping and spraying methods in layer-by-layer deposition of chitosan and sodium caseinate
(Izmir Institute of Technology, 2016-08) Üney, Sinem; Bayramoğlu, Beste
In this thesis; it is aimed to develop a novel, ultra thin, homogeneous edible coating with adequate gas barrier properties by layered deposition of chitosan and sodium caseinate with dipping and spraying methods and compare the coating structures. The parameters considered in this study are pH, adsorption times, number of layers and the types of the top layer. To determine the appropriate conditions, zeta potential and hydrodynamic diameter measurements of chitosan and sodium caseinate were done. After determining the appropriate concentrations and pH values, layer deposition has been initiated. Following the formation of multilayer coating by UV-Vis spectrophotometer, the most suitable combination was determined for the formation of multilayer coating. Multilayered coating characterization was done by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Surface Plasmon Resonance which allows to observe coating formation in-situ. Moreover antimicrobial activity, water vapor permeability and oxygen permeability were also investigated. It has been observed that the multilayer coating structures obtained by dipping and spraying methods have some differences. The formation of multilayer coating has been followed successfully with UV-Vis spectrophotometer; besides information about surface topography and coating thickness is obtained by Atomic Force Microscopy (AFM). The multilayered coatings have no significant effects on oxygen permeability and water vapor permeability; however it has contact antimicrobial effect.
The confirmation of the commercial kits used in the detection of antibiotics in milk with HPLC (high pressure liquid chromatography)
(Izmir Institute of Technology, 2008) Alkan, Pınar; Tarı, Canan
In this study, Charm II Assay was confirmed by HPLC for B-lactam, sulphonamide and tetracycline residues in milk. These antibiotics were chosen because they are most frequently used veterinary drugs and their detection have importance for milk quality and consumer's health. The results for confirmation of Charm II Assay showed that the test was very sensitive to all groups that were investigated and showed %100 true results for blank samples and spiked samples that were fortified with mixed standards at MRL (maximum residue limit) for each group. Average recoveries of HPLC used for confirmation were between 47% to 97% for beta-lactams, 61.5% to 84.8% for tetracyclines and 50.4% to 54.6% for sulphonamides. The results of analysis with the naturally contaminated milk samples showed that Charm II Assay may give false positive results. But this might be because of the high sensitivity of the test that sometimes HPLC may not reach that detection limit of Charm II assay or the milk samples may contain other compounds of investigated antibiotics that HPLC method can not detect.In samples that were collected for B-lactam determination, only 2 out of 81 samples were detected above MRL where the amounts were 6.5 ppb penicilin-G and 23.8 ppb ampicillin. The MRL for these B-lactam antibiotics are specified as 4 ppb by European Union regulations. The samples investigated for tetracycline residues which were found as positive and confirmed by HPLC were below MRL or negative. In samples investigated for sulphonamides only one sample out of 44 was above MRL where the amount was 119 ppb sulfamethazine.Analysis with 5 commercial milk samples showed none antibiotic residues. Only 4 samples out of 5 for sulphonamides were screened positive but after confirmation no residues were detected in these samples.
Control of microbial and enzymatic changes in intermediate moisture sun-dried figs by mild heating and hydrogen peroxide disinfection
(Izmir Institute of Technology, 2003) Demirbüker Kavak, Dilek; Yemenicioğlu, Ahmet
During cold storage, the enzyme pectin methylesterase (PME) caused softening and lossof desired gummy texture in rehydrated intermediate moisture (IM) sun-dried figs. Heat inactivation studies indicated that the purified PME can be inactivated rapidly at 80 o and 90 oC. However, at or below 70 oC the enzyme showed activation by heating and inactivated very slowly. The in-situ activation of PME occurred much more extensively when sun-dried figs were rehydrated between 70o and 90 oC to produce IM figs with approximately 30 % moisture and this prevented the effective inactivation of enzyme even by rehydrations conducted at 80 o and 90 oC. The partial reduction of PME enzyme activity (almost 30 %) by rehydration of figs at 80 oC for 16 min may be used to delay undesirable textural changes in cold stored IM figs for 3 months. However, for longer storage periods hot reyhdration alone is not sufficient to prevent softening. No considerable yeast and mold growth was detected in IM figs cold stored 3-3.5 months.However, in some samples rehydrated in water at 80 oC, the total mesophilic aerobic counts and total yeast and mold counts showed a considerable increase when storage time exceeded 3-3.5 months. The rehydration of IM figs in 2.5 % H2O2 for 16 min at 80 oC reduced the total mesophilic aerobic microbial count of figs almost 90 %. Due to bleaching caused by H2O2, the brown fig color turned to a desirable and stable yellowlight brown as well. However, during cold storage the O2 gas released due to the decomposition of H2O2 by in situ fig catalase, accumulated within figs and caused some physical defects. Also, the residual level of H2O2 in the homogenates of disinfected figs was too much (300 ppm) and it seemed unlikely to eliminate this amount of H2O2 by physical or chemical means during processing. Pureeing IM figs eliminated residual H2O2 very rapidly. The application of rehydration first in 2.5 % H2O2 solution at 80 oC for 4 or 8 min and then in hot water at the same temperature for 12 or 8 min, respectively, also reduced the amount of residual H2O2 in IM figs considerably.Besides, these two-stage rehydration procedures eliminated the physical defects occurred in IM figs due to O2 gas release and gave firmer IM figs. To reduce the initial microbial load of IM figs, 4 and 8 min disinfections conducted in H2O2 solutions were less effective than 16 min disinfection in H2O2 solution. However, both 4 and 8 min disinfections effectively suppressed microbial load for at least 3.5 months and they may be used in the production of SO2 free light colored fig products.
Design and thermal analysis of a rotating solar building
(Izmir Institute of Technology, 2005) Karadağ, Çağlar; Günaydın, Hüsnü Murat
In recent years, various rotating buildings such as residential buildings, restaurants and pubs have been designed and constructed. Most of these rotating buildings do not possess passive solar design features or they cannot respond passive solar design principles entirely because the primary design purpose of these rotating buildings is to make all spaces view the landscape as required.Passive solar design is the optimum utilization of architectural peculiarities of a building and appropriate material selection for improving energy efficiency of a building in heating, cooling and natural lighting. While projecting a passive solar building, different factors including building orientation, latitude of the location and climatic properties must be taken into consideration.Although passive solar buildings are superior to conventional buildings in terms of various aspects, they have some deficiencies as well. Despite insulation, largesouthfacing windows which are designed to maximize solar heat gain in winter turn out to be heat loss areas in cold winter nights. They also cause excessive solar heat gain in summer. So as to eliminate such disadvantages of passive solar buildings, direction of buildings can be changed in winter and in summer by rotating them. In this project, a rotating building.s thermal performance is investigated. For doing this, a thorough literature review is carried out. First, passive solar design tools are identified. Second, examples of rotating buildings are analysed. Then, a rotating cafe located at IZTECH Campus . IYTE Cafe - is designed on the basis of passive solar design criteria. The cafe is assumed to be rotating two times a year and performance of the building is compared with a conventional passive solar building by calculating heat gain and heat loss of each building. It is found that, substantial energy savings could be possible through a rotating building. Furthermore, energy savings in summer and in winter conditions are calculated respectively as 14 % and 23 %.
Design criteria for increasing environmental performance of recreational areas: Analysis of Kordon/Izmir
(Izmir Institute of Technology, 2010) Uzakgören, Yasemin; Arkon, Cemal
In recent years, the increasing scale of urbanization and becoming more distant to our surroundings and ourselves are good reasons to analyze recreational areas. Recreational areas . a type of urban open spaces - are a necessity for human wellbeing that they provide opportunities, or openings, for certain activities, such as play, watching and walking, while the benefits associated with such activities might relate to improved mental and physical health. As planning these areas is not sufficient by itself, design criteria for increasing environmental performance of recreational areas has to be put forward, which is done by this study. This study will focus on environmentally performed urban open spaces on shorelines, and analysis will be carried out on four dimensions of the organization named The Project of Public Space (PPS,) which are formed from the seven dimensions of Lynch. Lynch has defined seven dimensions to analyze the urban space, which are Vitality, Sense, Fit, Access, Control, Efficiency, and Justice. On the other side, PPS.s dimensions are Access and Linkages, Uses and Activities, Comfort and Image, and Sociability. The case study will be about Kordon, known as Kordon 1st (or Atatürk Boulevard) which has a very dramatic history about transforming from a proposed 2x3 freeway to a recreational area. As the actual Structure Plan of Kordon starts from the viaduct shafts at Alsancak Port and ends at Cumhuriyet Square, as of the sit boundaries around the area, this study is also limited between these two landmarks. The objectives of this study have been two-fold. The first is to understand the issues and to establish a knowledge base about the transformation process of Kordon area from proposed Freeway to Recreational Area as an Urban Open Space. The second is to evaluation of Kordon as a recreational area in the light of environmental performance. This study will hopefully be helpful to increase environmental performance of other planned or proposed recreational areas.
Determination of antibiotics in raw and uht milk samples by the image forming method of biocrystallization
(Izmir Institute of Technology, 2011-12) Pelvan, Merve; Ünlütürk, Sevcan
This study aims to investigate a new technique for the antibiotic residue analysis that can able to detect a wide range of antibiotic residues directly in raw and drinking milk by producing reliable and definitive results. "Biocrystallization method" was selected as a new technique to distinguish the raw and UHT milk samples containing antibiotic residues from the antibiotic free ones. This method is based on the crystallographic phenomenon that occurs after adding ionic substances to an aqueous solution of dihydrate CuCl2 and drying in a constant temperature and relative humidity. In this study, the raw and UHT milk samples was screened for antibiotic residues using New SNAP* Beta-Lactam (IDEXX Lab. USA) test kits. Then, the chemical properties of milk samples (e.g. fat%, protein%, lactose%, minerals%, SNF%) were determined. At the same time, biocrystallization method were optimized with antibiotic free raw milk samples. Evaluation of biocrystallograms was performed via a panel. The best biocrystallogram images were obtained for 6 ml of milk samples prepared from 0.5 % milk and 5% CuCl2.2H2O solution by mixing at a ratio of 3 (milk) to 1 (CuCl2.2H2O) dried at 30 Â°C ,60% relative humidity for 22 h. After optimization, the raw and UHT milk samples were spiked with Penicillin G (2, 4, 8 ppb) and Ampicillin (2, 4, 8 ppb) to generate biocrystallogram images at the optimized conditions. All the images were evaluated with a visual inspection. Biocrystallization method was successfully used to distinguish raw and UHT milk from the samples spiked with Penicillin G and Ampicillin. This method gave better results when discriminating naturally contaminated raw milk from antibiotic free raw milk.
Developing probiotic lozenges to improve oral health
(Izmir Institute of Technology, 2019-07) Elvan, Menşure; Harsa, Hayriye Şebnem; Baysal, Ayşe Handan
Recently, there is a great need to overcome complaints about oral health from children, mental and physically handicapped people who are inadequate in oral hygiene and after chemotherapy of cancer patients. With reduced body resistance, opportunistic Streptococcus mutans and Candida albicans in the mouth become dominant, causing disruption of oral health. Therefore, the effect of lactic acid bacteria on pathogens was investigated in order to protect oral health with the thesis study. Lactobacillus pentosus NRRL-B 227 was determined among the probiotic bacteria tested for this purpose and its activity on the pathogen Streptoccocus mutans ATCC 25175 and Candida albicans DSMZ 5817 was found in broth microdilution, agar overlay and planktonic culture assays except disc diffusion test. To reduce the number of pathogens in oral microflora, lozenges containing L. pentosus were developed. Three different lozenges with encapsulated and free bacteria and control lozenge were produced, kept at different temperatures; 4⁰C and 25⁰C. No significant decrease in viability of the encapsulated probiotic strain after lozenge production and storage at 4°C was observed, the probiotic amount in the lozenge initially counted as 7.84 log CFU/g, while 7.73 log CFU/g at the end of 3 months shelf life. However, lozenges stored at 25⁰C probiotics lost their vitality after one month. Additionally, lozenges containing free bacteria have lost viability rapidly. Color and water activity were observed differently in the formulations (p <0.05). The formulations maintained their microbiological safety during storage. Lozenge with L. pentosus NRRL-B 227 has a significant potential for improving oral health and provides an alternative to the diversification of products containing probiotics.
Developing spreadable peanut butters incorporated with the encapsulated potential psychobiotic Lactococcus lactis C19.1 strain
(01. Izmir Institute of Technology, 2023-03) Akkuş, Zeynep Aysun; Harsa, Hayriye Şebnem; Arslan Tontul, Sultan
In recent years, the partially processed food market has increased, partly due to the demand for fresh-cut or dried products. However, there is an increasing demand for foods enriched with physiologically active ingredients such as probiotics and prebiotics. From the nutrional point view, these two functional factors, have created a new market area for fruit and snack products. Peanuts have high nutritional value (24% protein, 45% fat and 13% fiber) as well as high amounts of thiamine and niacin). It is also known to reduce the risk of prostate, liver, colon and lung cancer and stress-related diseases. In this study, as a model bacteria Lactococcus lactis C19.1 strain isolated from Turkish cottage cheese has been impregnated with peanut and cashew nut butter after encapsulation. In the selection of the Lactococcus lactis strain, porbiotic and anti-stress properties were considered. To increase the viability of the strain, the encapsulation was carried by whey protein-xylan complex as the wall material. After encapsulation, the probiotic strain was added to the peanut and cashew nut butter formulation. In addition, in order to determine the encapsulation efficiency, it was impregnated to the butters the free cell form. The results revealed that encapsulation increased the shelf life stability of the psychobiotic cell. The shelf life of the peanut butters containing free cell of L. lactis was determined as 30 days that of 45 days in encapsulated cell containing samples. In addition, in vitro analyzes revealed that encapsulation protected probiotic cells in simulated gastrointestinal system and, the viability was between 106 – 107 CFU/g. However, the viability rate was found to be 105 in fort he free cell containing samples after digestion test. Cashews and peanut butters containing encapsulated cell came to the fore, as 105 CFU/g remained below the 106 CFU/g, which is the condition of being probiotic.
Development and characterization of magnesium alginate hydrogels for 3d cell culture formation
(01. Izmir Institute of Technology, 2021-07) Çoban, Başak; Arslan Yıldız, Ahu; 01. Izmir Institute of Technology
Cell culture is an important tool for biological research. Two-dimensional (2D) cell culture is still used but growing cells on plastic surfaces offering unnatural growth kinetics and cell attachment. Three-dimensional (3D) cell culture allows cells to growth in their 3D physical shape and interact with their surroundings which represent the natural microenvironment. Hydrogels are crosslinked networks, have become increasingly used biomaterial for 3D cell culture with their ability to simulate the nature of most soft tissues. In this thesis, a new methodology based on bio-patterning was developed to fabricate (3D) cellular structures by using Mg-alginate hydrogel and fabricated 3D cellular structures was utilized for drug screening studies. Mg-alginate hydrogel has a specific gelation/de-gelation characteristics compared to other types of hydrogels due to its weak polymer-ion interaction. In this study slow gelation and de-gelation property of Mg-alginate hydrogel was used for biopatterning of 3D cellular structures. Plackett-Burman and Box-Behnken design models were used to optimize parameters of Mg alginate-based biopatterning method while using HeLa cells as a model cell line. Then, the applicability of newly developed methodology was successfully demonstrated by using SaOS-2 and SH-SY5Y cells to fabricate 3D cellular structures. Cell proliferation and migration profiles were observed during long-term culturing with time-dependent light microscopy images. Also cell proliferation and viability of long-term cultured tumor models were analyzed by using Alamar Blue and Live/Dead assays. Moreover, F-actin, Collagen I, and DAPI staining/immunostaining was done to investigate cellular and extracellular components of 3D cellular structures for short and long-term culture times. Finally, the dose-response of fabricated 3D structures was evaluated and compared with standard 2D cell culture by applying doxorubicin (DOX). The IC50 values were calculated for 3D cellular structure of HeLa, SaOS-2 and SH-SY5Y cells as 8.2, 7.8, and 2.1 µM respectively while IC50 values of 2D controls obtained as 3.2, 4.4, and 0.2 µM respectively. These results were also statistically analyzed and dose responses were found significantly different according to t-test, which means 3D cellular structures were more resistant to drug exposure compared to 2D cell culture.

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