İkiz açıklar hipotezinin matematiksel analizi : Türkiye örneği

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır

Recreational fishers' motivations at wetland destinations: The push and pull theory approach

This study aimed at developing and validating a scale to examine recreational fishing tourists' motivations at wetland destinations by applying the push and pull motivation theory. Drawing on both qualitative and quantitative data from travelers participating in recreational fishing activities in Turkey, a scale generation phase was followed to develop a purified push and pull motivation scale. The findings revealed three push motivations (e.g., fishing, nature, and socio-cultural aspects of the destination) and three pull motivations (e.g., geographic attributes and infrastructure, local culture and customs, and activity). Furthermore, several theoretical and managerial implications with suggestions for further studies were discussed

HEATING CONTROL IN SMART CLOTHES

Akıllı sistemler, tekstil sektöründe günden güne artan uygulama alanı bulmaktadır. Ortam sıcaklığına göre fiziksel veya kimyasal olarak tepki veren tekstil malzemelerinin yanısıra elektronik yapıların, tekstil materyallerinin bir parçası olduğu yapılar da geliştirilmiştir. Bu çalışmada, Dokuz Eylül Üniversitesi Elektrik ve Elektronik Mühendisliği ile Tekstil Mühendisliği Bölümlerinin ortak çalışmaları sonucunda, elektronik özelliklere sahip, ısıtma fonksiyonlu bir giysi geliştirilmiştir. Isıtmanın sağlanması amacıyla çelik malzemeden yapılmış iletken iplikler kullanılarak ısıtıcı paneller üretilmiştir. Bu ısıtıcı panellere uygun olarak optimum bir güç kaynağı, elektronik devre ve bütün bu materyalleri üzerinde taşıyabilecek yelek tasarlanmış ve üretilmiştir. Sistem termal manken üzerinde test edilerek farklı yapılardaki ısıtma panelleri ile zamana göre ısıtma karakteristiği ve gerilim değişimleri elde edilmiştir. New systems have been improved for textile industry as electronic substructures combine with textile material instead of basic textile materials, which reaction variously physical and chemical according to media temperature. In this study, a heating cloth which includes electronic circuitry is developed by co-operation of Electrical and Electronics Engineering and Textile Engineering Departments of Dokuz Eylul University. Heater panels are produced by using steal based conductor threads to supply heating function. Fitting with these panels, optimum power source, electronic circuit and a waistcoat are designed and produced to carry all these materials. System is tested on a thermal mannequin and heating characteristic together with voltage change according to time are obtained using different heating panel configurations

Analysis of Chemical Structure and Antibiofilm Properties of Exopolysaccharides from Lactiplantibacillus plantarum EIR/IF-1 Postbiotics

Previous studies have indicated that the exopolysaccharides of lactic acid bacteria exhibit antibiofilm activity against non-oral bacteria by preventing their initial adhesion to surfaces and by downregulating the expression of genes responsible for their biofilm formation. The aims of this study were to (1) characterize the exopolysaccharides (EPSs) of Lactobacillus plantarum EIR/IF-1 postbiotics, (2) test their antibiofilm effect on dual biofilms, and (3) evaluate their bacterial auto-aggregation, co-aggregation, and hydrocarbon-binding inhibitory activity. The EPSs were characterized by FTIR, HPLC, and thermogravimetric analysis. Bacterial auto- and co-aggregation were tested by Kolenbrander's method and hydrocarbon binding was tested by Rosenberg's method. Dual biofilms were formed by culturing Fusobacterium nucleatum ATCC 25586 with one of the following bacteria: Prevotella denticola ATCC 33185, P. denticola AHN 33266, Porphyromonas gingivalis ATCC 33277, P. gingivalis AHN 24155, and Filifactor alocis ATCC 35896. The EPSs contained fractions with different molecular weights (51 and 841 kDa) and monosaccharides of glucose, galactose, and fructose. The EPSs showed antibiofilm activity in all the biofilm models tested. The EPSs may have inhibited bacterial aggregation and binding to hydrocarbons by reducing bacterial hydrophobicity. In conclusion, the EPSs of L. plantarum EIR/IF-1, which consists of two major fractions, exhibited antibiofilm activity against oral bacteria, which can be explained by the inhibitory effect of EPSs on the auto-aggregation and co-aggregation of bacteria and their binding to hydrocarbons.</p

Sermaye kontrollerinin çok boyutlu analizi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu çalışmada sermaye kontrolleri üzerinden matematiksel bir uluslararası makroiktisat modellemesi yapılmaktadır. Tez çalışması boyunca herhangi bir ekonomide çok sayıda makroiktisadi değişkenin karşılıklı etkileşimi dinamik ve genel denge vari ele alınmaktadır. Çok sayıda değişkenin bulunması anlamında 'karmaşık' ve bu değişkenler arasındaki ilişkilerin sürekli değişimi anlamında 'dinamik' olan iktisat alanında, genel geçer kabul edilen teoriler yerine bulmaca, paradokslar ve mantık oyunları platformundan sorunsalların temeline yaklaşımın köşetaşları tez boyunca ifade edilmektedir. Yapılan modelin dinamik kurgusu, sermaye kontrollerinin döviz kurundaki dalgalanmayı hem kısa hem de uzun dönemde azalttığı sonucuna varılmaktadır. Anahtar Kelimeler: Sermaye Kontrolleri, Diferansiyel Denklem Sistemi, Döviz Kru Değişkenliği, Para PolitikasıThe purpose of this study is to present an international macroecomic model. The interactions between a number of macroeconomic variables are analysed under a general equilibrium and dynamic approach. In the field of economics, whics is complex and dynamic, there shoul be an analysis platform based on puzzles, paradoxes and mind games rather than constant theories. This study shows the advantages of such a thinking. The dynamic chain of the models developed indicates that capital controls decrease the volatility of exchange rate both for long and short run. Keywords: Capital Controls, Differential Equation Systems, Volatility of Exchange Rate, Monetary Polic

Manothermosonication (MTS) treatment of apple-carrot juice blend: effect on inactivation of Escherichia coli O157:H7 and quality attributes during storage

With advantages such as requiring less time, saving energy and reducing the costs manothermosonication has become increasingly popular in the food processing industry in recent years. My thesis research was conducted to investigate the effect of manothermosonication (MTS) on microbial inactivation and the quality of apple-carrot blended juice during storage. To examine the effect of MTS on quality of apple-carrot blended juice samples treated with MTS and high temperature - short time (HTST) was examined during a 3-week period under refrigeration conditions. Quality attributes such as brix, total phenolic content, titratable acidity, viscosity, antioxidant capacity, turbidity, pH, and color of the samples were compared. The MTS treatment helped to achieve 5 log reduction in apple-carrot blended juice in relatively short time, especially at elevated temperatures. At 40oC, a maximum of 3.03 log CFU/ml after 75 s treatment at 300 kPa. At 50oC, 5 log reduction in the population of Escherichia coli O157:H7 was achieved in 60 s under all three pressures (100, 200, and 300 kPa). When temperature was increased to 60oC, only 30 s were needed to reduce the survival count of E. coli O157:H7 by 5 log cycles at 100, 200, and 300 kPa. MTS treatment of apple-carrot blended juice significantly affected chemical parameters such as total phenolic content, antioxidant and pH-value. The MTS treatment affected the antioxidant activities of apple-carrot blended juice during three weeks storage and a significant increase in antioxidant activity was recorded for samples treated with MTS during 3 weeks of storage. While the first day antioxidant activities of the samples were low, they were increased when measured on day 7, 14, and 21. Total phenolic content of apple-carrot blended juice treated by HTST was significantly lower compared to the samples treated with MTS. Turbidity of MTS-treated samples decreased significantly during 3 weeks of storage. Overall, apple-carrot blended juice treated with MTS showed good promise as an alternative to HTST as evidenced by effective microbial inactivation and ability to maintain juice quality

Separation of solvents from selected biopolymeric matrixes and aqueous mixtures by ultrasound

Distillation, one of the oldest separation processes, is of central importance in the chemical and process industries due to its ability to separate ideal, non-ideal, homogeneous, heterogeneous, and azeotropic mixtures in industrial-scale operations. It is the most commonly employed method for liquid-liquid separation applications. Distillation accounts for ~95% of the total separation energy used in the refining and chemical-processing industries (Leeson et al., 2017). Unfortunately, the energy efficiency of a commercial distillation column is fairly low, with a typical thermodynamic efficiency of less than 10% (Rush, 1980). There are two main reasons for its low efficiency. First, there are large irreversible heat-transfer losses in the phase-change processes of boiling a liquid and then condensing the vapor. Second, a significant fraction of energy is used to overcome the azeotropic bottleneck in azeotrope-forming systems (e.g., ethanol + water). While a few conventional distillation technologies and new separation approaches have been developed for azeotropes, they rely largely on separation via phase equilibrium, or involve large capital, energy, or other operating costs. Like distillation, drying is an energy-intensive process which removes the moisture content from biopolymer matrixes such as food products, for the purposes of reducing the costs of transportation and packaging, and for food preservation. The thermal energy that is required in a drying process, plus the fact that water removal in the falling-rate period is difficult, cause the drying foods to be exposed to elevated temperatures for a long time. Drying is thus a process that is known to degrade the product quality, especially the nutritional quality. Hence, ways are being sought to dry foods with heat-sensitive nutrients at low temperatures. Indeed, there is a crucial need to develop a new food-drying method that can preserve food quality and reduce energy consumption. In this project, a new approach has been proposed and tested for liquid-liquid and solid-liquid separations using ultrasonic waves at different frequencies. First, power ultrasound was used to separate ethanol from an ethanol-water mixture, with a focus on prototype development and optimization of process parameters, including the initial ethanol concentration, carrier gas-flow rate, temperature, and mist collection time. Additionally, the physicochemical properties of the ethanol-water mixture were investigated to gain a better understanding of ethanol and water interactions, which may provide insights for the selection of process parameters. The results showed that the ultrasound-mediated ethanol separation at low temperatures was effective in enriching ethanol in the ultrasound-generated mist. The volumetric flow rate of the carrier air was found to be an important parameter affecting the ethanol concentration in the mist. More importantly, this non-thermal, non-equilibrium separation method was able to break the ethanol-water azeotrope, showing promise for reducing energy consumption in the ethanol-production process. With regard to water removal from biomaterials (solid-liquid separation), a novel use of power ultrasound was tested for drying fabrics and apple slices with no or minimal application of heat. For drying the apple slices, the performance of ultrasonic drying was compared with those of two commonly used methods, freeze drying and hot-air drying. The effects of the non-thermal ultrasonic drying method on the drying kinetics, product-quality attributes, and microstructures of the apple slices were evaluated. The results obtained for the fabric drying showed that, regardless of the fabric type, room-temperature ultrasound drying with a high-frequency transducer significantly reduced the drying time compared to ultrasound drying by a low-frequency mesh transducer or a hot-air drying method. The time needed to dry apples to a 5% moisture content (wet basis) was 81% faster for the ultrasonic contact-drying method than the hot-air drying method at 60±1oC. The apple slices processed by the ultrasound also maintained a significantly higher rehydration ratio, antioxidant capacity, total phenol content, better color, and microstructure than the hot-air-dried samples. Overall, the novel ultrasonic, non-thermal, solvent-separation schemes proposed and tested in this study demonstrated a significant improvement over the current technologies in ethanol-enrichment and food dehydration processes. The information obtained in this study will provide important guidelines for the future development of pilot scale and industrial scale operations

Separation of solvents from selected biopolymeric matrixes and aqueous mixtures by ultrasound

Distillation, one of the oldest separation processes, is of central importance in the chemical and process industries due to its ability to separate ideal, non-ideal, homogeneous, heterogeneous, and azeotropic mixtures in industrial-scale operations. It is the most commonly employed method for liquid-liquid separation applications. Distillation accounts for ~95% of the total separation energy used in the refining and chemical-processing industries (Leeson et al., 2017). Unfortunately, the energy efficiency of a commercial distillation column is fairly low, with a typical thermodynamic efficiency of less than 10% (Rush, 1980). There are two main reasons for its low efficiency. First, there are large irreversible heat-transfer losses in the phase-change processes of boiling a liquid and then condensing the vapor. Second, a significant fraction of energy is used to overcome the azeotropic bottleneck in azeotrope-forming systems (e.g., ethanol + water). While a few conventional distillation technologies and new separation approaches have been developed for azeotropes, they rely largely on separation via phase equilibrium, or involve large capital, energy, or other operating costs. Like distillation, drying is an energy-intensive process which removes the moisture content from biopolymer matrixes such as food products, for the purposes of reducing the costs of transportation and packaging, and for food preservation. The thermal energy that is required in a drying process, plus the fact that water removal in the falling-rate period is difficult, cause the drying foods to be exposed to elevated temperatures for a long time. Drying is thus a process that is known to degrade the product quality, especially the nutritional quality. Hence, ways are being sought to dry foods with heat-sensitive nutrients at low temperatures. Indeed, there is a crucial need to develop a new food-drying method that can preserve food quality and reduce energy consumption. In this project, a new approach has been proposed and tested for liquid-liquid and solid-liquid separations using ultrasonic waves at different frequencies. First, power ultrasound was used to separate ethanol from an ethanol-water mixture, with a focus on prototype development and optimization of process parameters, including the initial ethanol concentration, carrier gas-flow rate, temperature, and mist collection time. Additionally, the physicochemical properties of the ethanol-water mixture were investigated to gain a better understanding of ethanol and water interactions, which may provide insights for the selection of process parameters. The results showed that the ultrasound-mediated ethanol separation at low temperatures was effective in enriching ethanol in the ultrasound-generated mist. The volumetric flow rate of the carrier air was found to be an important parameter affecting the ethanol concentration in the mist. More importantly, this non-thermal, non-equilibrium separation method was able to break the ethanol-water azeotrope, showing promise for reducing energy consumption in the ethanol-production process. With regard to water removal from biomaterials (solid-liquid separation), a novel use of power ultrasound was tested for drying fabrics and apple slices with no or minimal application of heat. For drying the apple slices, the performance of ultrasonic drying was compared with those of two commonly used methods, freeze drying and hot-air drying. The effects of the non-thermal ultrasonic drying method on the drying kinetics, product-quality attributes, and microstructures of the apple slices were evaluated. The results obtained for the fabric drying showed that, regardless of the fabric type, room-temperature ultrasound drying with a high-frequency transducer significantly reduced the drying time compared to ultrasound drying by a low-frequency mesh transducer or a hot-air drying method. The time needed to dry apples to a 5% moisture content (wet basis) was 81% faster for the ultrasonic contact-drying method than the hot-air drying method at 60±1oC. The apple slices processed by the ultrasound also maintained a significantly higher rehydration ratio, antioxidant capacity, total phenol content, better color, and microstructure than the hot-air-dried samples. Overall, the novel ultrasonic, non-thermal, solvent-separation schemes proposed and tested in this study demonstrated a significant improvement over the current technologies in ethanol-enrichment and food dehydration processes. The information obtained in this study will provide important guidelines for the future development of pilot scale and industrial scale operations.LimitedAuthor requested closed access (OA after 2yrs) in Vireo ETD syste

SATELLITE ATTITUDE CONTROL USING DISSIMILAR REDUNDANT ACTUATORS

Low Earth orbit satellites are usually equipped with magnetic torquers for momentum dumping and reaction wheels to carry out three axis attitude stabilization and control. These two different types of actuators mixed and used together to carry out slew maneuvers. The problem of allocating the control to these different types of actuators is realized using a recently developed algorithm called blended inverse. The algorithm is compared with the Moore-Penrose pseudo inverse demonstrating its success in realizing the desired maneuver while overcoming singularities

Physicochemical and Functional Modifications of Hemp Protein Concentrate by the Application of Ultrasonication and pH Shifting Treatments

According to the Food and Agriculture Organization (FAO), protein demand is expected to increase globally by around 40% by 2030 as a response to the world&rsquo;s population growth. Due to their clean label, vegan or vegetarian based applications, nutritional value, and cost-efficient properties, plant-based proteins have been widely studied. However, most of the alternatives currently found in the market have some challenges because of their poor solubility, emulsifying, gelling, and foaming attributes. Hemp seed protein has gained increasing attention due to its unique amino acids and fatty acids profiles. In this study, commercial HPC mixtures were adjusted to pH 2, 4, 6, 8, 10, and 12 followed by ultrasonication (US) for 5 min (5 s on: 5 s off) and incubated for an hour before neutralizing to pH 7. Following the treatments, the samples were analyzed for their hydrodynamic diameter, conductivity, zeta potential, polydispersity index, surface hydrophobicity, solubility, electrophoresis (SDS-PAGE), free sulfhydryl group, and optical characteristics. The samples treated with ultrasound at pH 8 and 10 significantly (p &lt; 0.05) enhanced the solubility of the hemp seed protein by 12.12% and 19.05%, respectively. Similarly, the samples treated with ultrasonication and pH shifting at pH 6, 8, and 10 also significantly increased the amount of free sulfhydryl content (p &lt; 0.05) to 41.6, 58.72, and 46.54 mmol/g from 32.8 mmol/g, respectively. This study shows that the application of ultrasonication and pH shifting is a promising alternative method to modify the functional properties of HPC and widen their applications in the food, cosmetics, and pharmaceutical industries