Robust network design under polyhedral traffic uncertainty

Ankara : The Department of Industrial Engineering and The Institute of Engineering and Science of Bilkent Univ., 2007.Thesis (Ph.D.) -- Bilkent University, 2007.Includes bibliographical references leaves 160-166.In this thesis, we study the design of networks robust to changes in demand estimates. We consider the case where the set of feasible demands is defined by an arbitrary polyhedron. Our motivation is to determine link capacity or routing configurations, which remain feasible for any realization in the corresponding demand polyhedron. We consider three well-known problems under polyhedral demand uncertainty all of which are posed as semi-infinite mixed integer programming problems. We develop explicit, compact formulations for all three problems as well as alternative formulations and exact solution methods. The first problem arises in the Virtual Private Network (VPN) design field. We present compact linear mixed-integer programming formulations for the problem with the classical hose traffic model and for a new, less conservative, robust variant relying on accessible traffic statistics. Although we can solve these formulations for medium-to-large instances in reasonable times using off-the-shelf MIP solvers, we develop a combined branch-and-price and cutting plane algorithm to handle larger instances. We also provide an extensive discussion of our numerical results. Next, we study the Open Shortest Path First (OSPF) routing enhanced with traffic engineering tools under general demand uncertainty with the motivation to discuss if OSPF could be made comparable to the general unconstrained routing (MPLS) when it is provided with a less restrictive operating environment. To the best of our knowledge, these two routing mechanisms are compared for the first time under such a general setting. We provide compact formulations for both routing types and show that MPLS routing for polyhedral demands can be computed in polynomial time. Moreover, we present a specialized branchand-price algorithm strengthened with the inclusion of cuts as an exact solution tool. Subsequently, we compare the new and more flexible OSPF routing with MPLS as well as the traditional OSPF on several network instances. We observe that the management tools we use in OSPF make it significantly better than the generic OSPF. Moreover, we show that OSPF performance can get closer to that of MPLS in some cases. Finally, we consider the Network Loading Problem (NLP) under a polyhedral uncertainty description of traffic demands. After giving a compact multicommodity formulation of the problem, we prove an unexpected decomposition property obtained from projecting out the flow variables, considerably simplifying the resulting polyhedral analysis and computations by doing away with metric inequalities, an attendant feature of most successful algorithms on NLP. Under the hose model of feasible demands, we study the polyhedral aspects of NLP, used as the basis of an efficient branch-and-cut algorithm supported by a simple heuristic for generating upper bounds. We provide the results of extensive computational experiments on well-known network design instances.Altın, AyşegülPh.D

The Energy of a Domain on the Surface

We compute the energy of a unit normal vector field on a Riemannian surface M. It is shown that the energy of the unit normal vector field is independent of the choice of an orthogonal basis in the tangent space. We also define the energy of the surface. Moreover, we compute the energy of spheres, domains on a right circular cylinder and torus, and of the general surfaces of revolution.Розраховано енергію одиничного нормального векторного поля на рiмановiй поверхні M. Показано, що енергія одиничного нормального векторного поля не залежить від вибору ортогонального базиса в дотичному просторі. Визначено енергію поверхні. Більш того, розраховано енергію сфер, областей на прямому круговому циліндрі та торі і, більш загально, поверхонь обертання

Letters from Tayyib Gökbilgin’s personal archives : László Rásonyi

Tayyib Gökbilgin, who ranks among the founding fathers of Ottoman studies, was the first student of Faculty of Language, History, and Geography in Ankara, the new capital of the new state, where he began studying Hungarology as a student of László Rásonyi. The correspondences in Gökbilgin's personal collection offer a very interesting and valuable picture of a very complex period, in which the individual perspectives of scholars on the socio-political environment can also be traced. The aim of this article is to present the exemplary letters of László Rásonyi, the first head of the Department of Hungarology to his first student and later colleague Tayyib Gökbilgin in the context of the personal archive and first-person documents

Synthesis and characterization of monodispere silica based functional nanoparticles for multi-purpose applications

Thesis (Master)--İzmir Institute of Technology, Chemistry , İzmir, 2009Includes bibliographical references (leaves: 81-84)Text in English; Abstract: Turkish and Englishxiii, 84 leavesThe Stöber method was performed to tune the size of monodisperse silica nanoparticles in the range of 10 to 500 nm. It was observed that increasing amount of reactants favors the formation of larger particles A Stöber method in the presence of L-lysine as a catalyst instead of ammonia was developed to prepare well-ordered, highly monodisperse silica nanoparticles based on the hydrolysis and condensation of TEOS. The effect of medium temperature, amounts of L-lysine, TEOS, octane and dye on the size of particle was investigated. It was found that L-arginine increased the size of particles. The amount of TEOS was determined to be 50.0 mmol to obtain the smallest size of particle. The mole of L-lysine slightly altered the size of particles, however the surface of particles was substantially covered by L-lysine. The presence of octane does not change the size of particles. The amount of dye molecule Rhodamine B isothiocyanate (RBITC) does not alter the size of nanoparticles. We showed that temperature plays important role tuning the particle size from 5.0 nm to 80.0 nm.MTT assay indicates no cytotoxicity of the silica particles against MCF-7 (human breast cancer cell lines) and PC-3 (human prostate cancer cell lines) cancer cell lines. The particles enter to the cells within 5 minutes with a concentration of 0.1.g/mL. We propose that these particles can be used in the field of bioimaging and drug delivery

The economic analysis of geothermal / absorption cooling of a hospital: Case study of Dokuz Eylül University Research and Application Hospital

Thesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2006Includes bibliographical references (leaves: 88-90)Text in English; Abstract: Turkish and Englishxvi, 158 leavesDokuz Eylül Research and Application Hospital, founded in 1982, is located in İnciraltı Place, in Balçova. It is placed at the south of İzmir and between the İzmir-Çeşme Highway and İzmir-Çeşme Super Highway. Rather rich geothermal resources found in Balçova, provides the use of geothermal water for heating in the hospital. However, the required cooling capacity for the hospital, which is relatively massive when compared with the residents, has been supplied by conventional compression chillers. In this study, the aim is to decrease the overall annual costs incurred by cooling of the hospital by implementing an absorption cooling system, which uses geothermal fluid as the heating source. The main idea behind this implementation is that the electricity consumption of an absorption chiller is minimal when compared with a compression chiller. On the other hand, since the source that is going to be used in the system is geothermal energy, there will be an additional cost incurred by the use of geothermal fluid. So, the economic analysis that is going to be conducted involves the comparison of two alternatives, which are leaving the system as is now and implementing an absorption cooling system. To minimize the costs incurred by the implementation of an absorption cooling system, instead of supplying the full capacity of the hospital, a moderate capacity will be supplied by the absorption chillers, by using the existing compression chillers as the peaking units. Since it is not known which capacity will be suitable for the needs, several absorption cooling machines with various capacities will be examined. After comparing these mutually exclusive alternatives, the effect of the change in geothermal fluid price on the implementation of an absorption cooling system, and the break-even geothermal water price will be found. At the end, the investment worth values of the selected absorption cooling machines will be examined to decide whether to implement an absorption cooling system in the hospital or not

The effect of reading comprehension instruction enriched with cultural materials on students' vocabulary knowledge and attitudes towards English course

Bu araştırmada yedinci sınıf öğrencilerine verilen kültürel materyallerle zenginleştirilmiş okuduğunu anlama öğretiminin öğrencilerin kelime hazineleri ve İngilizce dersine yönelik tutumlarına etkisi incelenmiştir. İlk olarak görüşmeler ve doküman analizleri yapılarak bir ihtiyaç analizi gerçekleştirilmiştir. İhtiyaç analizinden elde edilen sonuçlar doğrultusunda bu araştırmanın yapılmasına karar verilmiştir. Araştırmanın çalışma grubunu, 2013–2014 eğitim öğretim yılı bahar yarıyılında Aydın ili Efeler ilçesindeki orta sosyo-ekonomik düzeydeki bir devlet okulunun iki yedinci sınıf oluşturmaktadır. Araştırmada öntest-sontest kontrol gruplu yarı deneysel model kullanılmıştır. Araştırmada deney ve kontrol gruplarına, uygulama öncesi "Kelime Hazinesi Başarı Testi" ve "İngilizce Dersine Yönelik Tutum Ölçeği" uygulanmıştır. Deney grubundaki öğrencilere 2013-2014 eğitim öğretim yılının bahar döneminde haftada iki ders saati olmak üzere altı hafta süresince kültürel materyallerle zenginleştirilmiş okuduğunu anlama öğretimi uygulanmıştır. Kontrol grubu ise normal öğretim programına devam etmiştir. Deney grubundaki etkinlikler araştırmacı tarafından yürütülürken, kontrol grubundaki etkinlikler kendi İngilizce öğretmenleri tarafından yürütülmüştür. Uygulamaların sonunda "Kelime Hazinesi Başarı Testi" ve "İngilizce Dersine Yönelik Tutum Ölçeği" gruplar arasında farklılıkları değerlendirmek amacıyla sontest olarak tekrar uygulanmıştır. Ayrıca "Kelime Hazinesi Başarı Testi" kelimelerin kalıcılığını test etmek amacıyla sontestin uygulanmasından altı hafta sonra her iki gruba tekrar uygulanmıştır. Araştırmada elde edilen bulgular incelendiğinde, kültürel materyallerle zenginleştirilmiş okuduğunu anlama öğretiminin kelime hazinesi seviyesinin gelişimine ve İngilizce dersine yönelik tutuma olumlu yönde katkı sağladığı görülmüştür.In this research, the effect of reading comprehension instruction enriched with cultural materials given to the fourth grade students on students' vocabulary knowledge and attitudes towards English lesson is examined. First of all, a need analysis was done through interviews and document analyses. In accordance with the results obtained from the needs analysis, this research was decided to be done. The study group comprises two seventh grades at a socio-economic middle-level public school in Aydın province at the spring semester of 2013-2014 academic year. In the research, pre-test and post-test quasi-experimental model was used. In the research, "Achievement Test for Vocabulary" and "Scale for Attitudes towards English Course" were applied to experimental and control groups before the practices. Reading comprehension instruction enriched with cultural materials having two course hours per week was given to the students in experimental group in the spring semester of 2013-2014 academic year for six weeks. On the other hand, the control group followed their traditional reading comprehension instruction. The activities in the experimental group have been carried out by the researcher while the control group has followed his English course with their own English teacher. At the end of the practices, "Achievement Test for Vocabulary" and "Scale for Attitudes towards English Course" has been applied as post-test in order to assess the differences between groups. Also, "Achievement Test for Vocabulary" has been applied again to determine the retention of the vocabulary knowledge. According to the results, it is seen that reading comprehension instruction enriched with cultural materials positively contributed to students' vocabulary knowledge and attitudes towards English course

Illustrating the discussions on Ottoman studies in the early Republican Turkey through Tayyib Gökbilgin

Tayyib Gökbilgin, who ranks among the founding fathers of Ottoman studies was one of the most influential historians of the early period of the Turkish Republic. He was also one of the prominent historians who conducted numerous researches on Ottoman–Hungarian historical relations. Gökbilgin was the first student of Faculty of Language, History, and Geography (Dil, Tarih, Coğrafya, Fakültesi) in the new capital of the new state, namely in Ankara where he began studying Hungarology/Hungarian Studies as a student of László Rásonyi. The modern practice of history and the advancement of the nation-state progressed side by side and Tayyib Gökbilgin had maintained his modernist Turkish nationalist identity and emphasized that one of the fundamental aims of history was to feel proud with the historical past of the Turks. One can coincide with this statement in almost all historians of the period since it was the clearest example of efforts to legitimize Ottoman history as a part of World history. Tayyib Gökbilgin, like the way his contemporaries, followed the mission of his professor Fuad Köprülü and tried to reveal the truth of the matters that the western world conceptualized incorrectly with incomplete materials, with the capability provided by the authority given by the utilization of the original sources. He, like many of his colleagues, had also a particular interest, an intellectual purpose of breaking down the prejudices against the Ottomans and thus the Turks. It would not be wrong to state that his historiography emerged from this core. However, it also does not mean that he creates an Ottoman admiration or exaltation adorned with unnecessary heroic stories at the opposite end while trying to realize his purpose. What I plan to proceed in this presentation is to evaluate Tayyib Gökbilgin’s contribution to writing Ottoman History and efforts to legitimize Ottoman History as a part of World History while maintaining his modernist Turkish nationalist identity that was formed by the developments within nation-building process in the late Ottoman and early Republican era.Tayyib Gökbilgin, who ranks among the founding fathers of Ottoman studies was one of the most influential historians of the early period of the Turkish Republic. He was also one of the prominent historians who conducted numerous researches on Ottoman–Hungarian historical relations. Gökbilgin was the first student of Faculty of Language, History, and Geography (Dil, Tarih, Coğrafya, Fakültesi) in the new capital of the new state, namely in Ankara where he began studying Hungarology/Hungarian Studies as a student of László Rásonyi. The modern practice of history and the advancement of the nation-state progressed side by side and Tayyib Gökbilgin had maintained his modernist Turkish nationalist identity and emphasized that one of the fundamental aims of history was to feel proud with the historical past of the Turks. One can coincide with this statement in almost all historians of the period since it was the clearest example of efforts to legitimize Ottoman history as a part of World history. Tayyib Gökbilgin, like the way his contemporaries, followed the mission of his professor Fuad Köprülü and tried to reveal the truth of the matters that the western world conceptualized incorrectly with incomplete materials, with the capability provided by the authority given by the utilization of the original sources. He, like many of his colleagues, had also a particular interest, an intellectual purpose of breaking down the prejudices against the Ottomans and thus the Turks. It would not be wrong to state that his historiography emerged from this core. However, it also does not mean that he creates an Ottoman admiration or exaltation adorned with unnecessary heroic stories at the opposite end while trying to realize his purpose. What I plan to proceed in this presentation is to evaluate Tayyib Gökbilgin’s contribution to writing Ottoman History and efforts to legitimize Ottoman History as a part of World History while maintaining his modernist Turkish nationalist identity that was formed by the developments within nation-building process in the late Ottoman and early Republican era

Landslide-Triggering Factors in Korucak Subbasin, North Anatolian, Turkey

AbstractKorucak Creek Basin is located within upper course of the Yeşilırmak River Basin and southern Middle Karadeniz (Black Sea) section which is known to have the potential of landslide and flood risk. The purpose of identification of landslide-triggering factors is to highlight the regional distribution of potentially unstable slopes and to guide decision makers for regional planning purposes. We assessed morphometric parameters for landslide-triggering factors of Korucak Creek Basin using GIS (Geographical Information System). These parameters are Stream Power Index (SPI) and Compound Topographic Index (CTI). Moreover, slope and elevation values of the basin were classified and superposed over the geologic map. Landslide locations were identified from topographic maps and verified with field observation. The total catchment area of the basin is about 55 km2. More than half of the total basin is covered by metamorphic rock types such as schist, which has high permeability and weakness against erosion and is one of the main causes of the landslides. The results show that the main triggering factors are slope and lithology. Thus, northern and western of the Korucak subbasin are under the highest-risk landslide areas

Fortification Of Ayran (drinking Yoghurt) With Encapsulated Cocoa Hull Waste Extract By Nano-liposomal Sytems, Shelf Life And Bioaccessibility Studies

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2016Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2016Bu tezde, ayran enkapsüle edilen kakao kabuğu fenolikleri ile zenginleştirilmiştir (1:10 w/w). Enkapsülasyonda nano-lipozomal sistemler olan kitosanla kaplı ikincil ve püskürtmeli kurutulmuş lipozomlar kullanılmıştır. Kakao kabuğu fenoliklerinin bu sistemler ile korunma seviyeleri ve biyoyararlılıkları ayran formülasyonunda raf ömrü süresince incelenmiştir. Zengin fenolik içeriğine sahip kakao kabuğu atığı ekstraktının içerdiği biyoaktif bileşenlerin nano-lipozomal sistemler ile enkapsüle edilmesi ile bu aktif bileşenler olumsuz çevre koşullarıdan korunmuş olmakta ve bu bileşenlerin biyoyararlılıkları arttırılmaktadır. Bu çalışmada kakao kabuğu atığı ekstraktı iyi-dağılımlı aniyonik lipozomlar ile farklı konsantrasyonlarda (0,1-0,9 %) enkapsüle edilmiştir. Lipozomların enkapsülasyon veriminin ve partikül büyüklüklerinin ekstrakt konsantrasyonuna bağlı olduğu gözlemlenmiştir. Enkapsülasyon veriminin tespiti için toplam fenolik madde miktarı, toplam antioksidan miktarı ve toplam flavonoid madde miktarı spektrofotometrik yöntemler kullanılarak tespit edilmistir. Toplam fenolik madde miktarı tayininde Folin–Ciocalteu, toplam antioksidan madde miktarı tayininde CUPRAC (cupric ion reducing antioxidant capacity) ve DPPH (2,2-diphenyl-1-picrylhydrazyl) metotları kullanılmıştır. 0,2% ağırlık/hacim konsantrasyonda maksimum enkapsülasyon verimi elde edilmiştir. Bu konsantrasyonda partikül büyüklüğü 157 nm ve ζ –potansiyali – 25 mV olarak ölçülmüştür. Lipozomun yapısal dayanıklılığını arttırmak için lipozom yüzeyi kitosan ile kaplanmış ve daha sonra püskürtmeli kurutucu kullanılarak yüzeyleri kitosan ile kaplanan lipozomlar toz hale getirilmiştir. Kitosan ile kaplanmamış olan birincil lipozomların yüzeyleri tabaka tabaka depozisyon yöntemi kullanılarak katyonik kitosan (0,4 ağırlık/hacim %) ile kaplanmış ve maltodekstrin (20 ağırlık/hacim %) ile karıştırıldıktan sonra püskürtmeli kurutucu ile katı forma getirilmiştir. Birincil lipozomların kitosan ile kaplanmış ikincil lipozomların ve toz forma getirilen lipozomların enkapsülasyon verimleri karşılaştırılmış, sonuç olarak; toz formdaki lipozomların en yüksek enkapsülasyon verimine sahip olduğu tespit edilmiştir. Bunların yanı sıra dondurularak kurutulmus kakao kabuğu atığı exkstraktının, püskürtmeli kurutucuda kurutularak toz forma getirilmiş kakao kabuğu atığı exkstraktının, ikincil lipozomlardaki kakao kabuğu atığı exkstraktının ve toz formdaki lipozomlardaki kakao kabuğu atığı ekstraktının içerdiği biyoaktif bileşenlerin in vitro sindirimi öncesi ve sonrası korunumları spektrofotometrik yöntemler (toplam fenolik madde miktarı, toplam antioksidan miktarı ve toplam flavonoid madde miktarı tespiti) kullanılarak karşılaştırılmış sonuç olarak toz formdaki lipozomların en iyi korumayı sağladığı tespit edilmştir. Buna ilaveten lipozom ile enkapsüle edilen kakao kabuğu atığı ekstarktlarındaki biyoaktif bileşenler in vitro sindirim sırasında enkapsüle edilmeyenlere göre daha az degradasyona uğramıştır. Lipozom yüzeyinin kitosan ile kaplanması lipozom yapısını sağlamlaştırmış toz forma getirmek yapıyı daha da dayanıklı hale getirmiş ve biyoyararlılığı arttırmıştır. Kakao kabuğu fenoliklerinin biyoyararlılıkları diğer örneklere göre püskürtmeli kurutulmuş lipozomlarda en az 4 kat daha fazla bulunmuştur. Ultra yüksek performanslı sıvı kromotografisi kullanılarak enkapsüle edilmemiş (dondurarak kurutulmuş ve püskürtmeli kurutucuda toz forma getirilmiş) ve enkapsüle edilmiş (kitosan ile kaplı olan ikincil lipozomlar ve püskürtmeli kurutucu ile toz forma getirilen lipozomlar) olan kakao kabuğu atığı ekstraktının biyoyararlılıkları ve in vitro sindirim öncesi ve sonrası fenolik asit profilleri araştırılmış sonuç olarak 10 temel fenolik bileşen tespit edilmiştir bu bilesenler flavon-3-ol monomerleri, flavan (quercetin) and phenolic asitlerden meydana gelmektedir. Tespit edilen fenolik bileşenlerin mide-bağırsak sistemindeki in-vitro sindirimi fenolik bileşenlerin molekül yapısına ve lipozomdaki miktarlarına ve lipozomda bulundukarı yere (lipozomun iç tabakası olarak adlandırılan korda ya da lipozomun yüzeyinde) göre farklılıklar göstermektedir. Bunların yanı sıra fenolik bileşenlerin karbonhidrat ve yağ molekülleri ile etkileşimi bu bileşenlerin degradasyon seviyelerini ve biyoyararlılıklarını etkileyen bir diğer önemli parametredir. Yaptığımız çalışmalar göstermiştir ki; lipozom ile enkapsülasyon, biyoaktif bileşenlerin daha iyi korunmasını sağlayarak biyoyararlılıklarını arttırmıştır. Bununla beraber ikincil lipozomlar ile toz forma getirilen lipozomlar karşılaştırıldığında toz forma getirilen lipozomların biyoyararlıklılarının ve koruma seviyelerinin daha iyi olduğu tespit edilmiştir Tüm bu veriler ışığında ayran toz formdaki kitosan ile kaplanan lipozom ile enkapsüle edilmiş kakao kabuğu atığı ekstraktı ve sıvı formdaki kitosan ile kaplanan lipozom (ikincil) ile enkapsüle edilmiş kakao kabuğu atığı ekstraktı ile zenginleştirilmiştir. Sıvı bir ürün olan içilebilir yoğurda toz forma getirililmiş lipozomal yapıların katılmasının biyoaktif bileşenin korunması ve bu biyoaktif bileşenlerin biyoyararlılığına olan etkisi incelenmiştir. Bunun yanı sıra enkapsülsyonun kakao kabuğu atığı ekstraktındaki biyoaktif bileşenlerin korunumu ve biyoyararlılığı üzerine olan etkilerini tespit edebilmek için içilebilir yoğurt aynı zamanda; dondurularak kurutulmus kakao kabuğu atığı ekstraktı ve püskürtmeli kurutucuda toz forma getirilmiş kakao kabuğu atığı ekstraktı ile de zenginleştirilmiştir. Kontrol grubu olarak zenginleştirilme yapılamamış olan ayran örnekleri kullanılmıştır. Tüm ayran örnekleri 4°C depolanmış ve raf ömrü boyunca (15 gün) biyoaktif bileşenlerin korunumu ve biyoyararlılıkları incelenmiştir. Toz formdaki lipozom ile enkapsüle edilmiş kakao kabuğu atığı ekstraktı, ikincil lipozom ile enkapsüle edilmiş kakao kabuğu atığı ekstraktı, dondurularak kurutulmuş kakao kabuğu atığı ekstraktı ve püskürtmeli kurutucuda toz forma getirilmiş kakao kabuğu atığı ekstraktı ile de zenginleştirilen ayran örneklerindeki biyoaktif bileşen miktarları; toplam fenolik madde, toplam antioksidan madde ve toplam flavonoid madde miktarlarının spektrofotometrik yöntemler ile analizlenmesi ile tespit edilmiştir. Analizler 1. 5. 10. ve 15. günlerde in vitro sindirim öncesi ve sonrası yapılmış, raf ömrüne bağlı olarak znginleştirilmiş içilebilir yoğurt örneklerinin biyoyararlılıkları ve kakao kabuğu ekstraktlarındaki biyoaltif madde miktarlarındaki korunum incelenmiştir. Ayran, püskürtmeli lipozomlar ile zenginleştirildiğinde; kakao kabuğu fenoliklerinin korunumu dondurularak kurutulmuş kakao kabuğu fenolikleri ile zenginleştirmeye göre raf ömrü süresince in-vitro sindirim öncesi 2 kat sonrası, 5 kat artmıştır. Bu iki ayran örneği karşılaştırıldığında; püskürtmlei kurutulmuş lipozomlardaki kakao fenoliliklerinin raf ömrü boyunca biyoyararlılıklarının en az 7 kat arttığı saptanmıştır. Raf ömrü süresince ayran örneklerindeki kakao kabuğu atığı ekstraktlarının biyoaktif madde profili; in vitro sindirim öncesi ve sonrası ultra yüksek performanslı sıvı kromatografisi ile tanımlanmıştır. Tespit edilen fenolik maddeler, ayran ürününe katmadan önce dondurulmuş kakao kabuğu ekstraktındaki, püskürtmeli kurutucuda toz forma getirilmiş kakao kabuğu ekstraktındaki, ikincil lipozomdaki kakao kabuğu ekstraktındaki ve toz forma getirilmiş lipozomdaki kakao kabuğu ekstraktındaki biyoaktif bileşenler ile aynı olup; bozunma seviyelerine bağlı olarak bu biyoaktif bileşenlerin miktarları içilebilir ayran örnekleri arasında farklılık göstermektedir. Lipozomların yüzey yükleri lipozomun stabilitesini belirleyen önemli faktörlerden biridir. Aktif yüzey yüklerine sahip olan lipozomların bulundukları ortamdaki diğer moleküller ile etkileşime girmeleri ile lipozomların yapıları dağılabilir. Ayranın lipozomal yapılar kullanılarak biyoaktif bileşenlerce zenginleştirildiği bu çalışmada, lipozomlar ve ayran proteinlerinin etkileşimi lipozomların raf ömrü süresince dayanıklılığını etkileyen önemli faktörlerden biridir. Raf ömrü süresince in-vitro sindirim öncesi ve sonrası yapılan ultra yüksek performanslı sıvı kromotografisi analizlerinde ayrana katılmış olan toz forma getirilmiş lipozomların; ikincil lipozomlara göre kakao kabuğu atığı ekstraktlarındaki biyoaktif bileşenleri daha iyi koruduğu ve bu bileşenlerin biyoyararlılıklarını arttırdığı tespit edilmiştir. Bunlara ek olarak, lipozom ile enkapsüle edilmiş kakao kabuğu atığı ekstraktlarındaki biyoaktif bileşenler; enkapsüle edilmeyenlere göre ayranda raf ömrü süresince in-vitro sindirim öncesi ve sonrası daha az degrade olmuştur. Litaretürde yoğurt ve yoğurt ürünlerinin polifenolik ve fenolik maddelerce zenginleştirilmesi ile ilgili mevcut çalışmalar bulunmaktadır. Bununla beraber, lipozom ile enkapsüle edilerek korunumu ve biyoyararlılığı arttırılmış olan biyoaktif maddelerin ayrana katılması ve lipozomların bir gıda matrisi içerisindeyken biyoyararlılık çalışmasının yapılması bir ilktir. Bunların yanı sıra, bu çalışma tuz içeren geleneksel bir Türk içeceği olan ayranın biyoaktif maddelerce zenginleştirildiği ve raf ömrü süresince biyoyararlılık çalışmalarının yapıldığı ilk çalışmadır.In this thesis, ayran (drinking yoghurt) was fortificated (1:10 w/w) with encapsultated cocoa hull phenolics which extracted from cocoa hull waste. Nano-liposomal systems were used for encapsulation that were chitosan coated (secondary) liposomes and spray dried liposomes. The protection level of cocoa hull phenolics and their biovailability in these systems were investigated in fortificated ayran (drinking yoghurt) during shelf life period. Cocoa hull waste was a phenolic rich source and encapsulation of these bioactive compounds in nano-liposomal system was an intelligent way both to protect them negative environment conditions and to increase their bioavaibility. In these study we encapsulated cocoa hull waste extract (CHWE) by fine-disperse anionic liposomes with different concentration (0.1-1.0 %). Encapsulation efficiency of liposomes was depended on extract concentration which also effect the particle size of liposomes. The maximum encapsulation efficiency was found 73.6% in concentration 0.2% w/v and the particle size is 157 nm, the ζ –potential is – 25 mV at this concentration. To enhance the liposome structure, their surface was coated with chitosan and then were solidificated by spray dryer. Layer-by-layer deposition method was used for coated the primary anionic liposomes with cationic chitosan (0.4 w/v%) and before the spray drying they mixed with maltodextrin (MD) (20 w/v%). Change of encapsulation efficiency (EE%) of bioactive compounds in primary, chitosan coated (secondary) and spray dried liposome was investigated, the spray dried liposome had the higher EE%. The protection of cocoa hull phenolics by liposomal systems during in-vitro digestion was investigated by comparing freeze dried CHWE, spray dried CHWE, secondary liposome with CHWE and spray dried liposome with CHWE. The better protection of bioactive compounds in gastro-intestinal digestion (in-vitro) was supported by spray dried liposomes. It is showed that covering the liposomes with chitosan layer provided the liposome stability and getting them to dry powder forms enhanced both stability and bioaccessibility. The bioavailability of these compounds in spray dried liposome at least 4 times higher than freeze dried forms. The phenolic acids profile and their bioavailability of CHWE and the CHWE in nano-liposomal systems was determined by in ultra high performance liquid chromatography (UHPLC). There was detected 10 major phenolic compounds. Their stability in gastro-intestinal digestion showed differences which based on molecular structure of phenolic acids and their location in the liposome. The bioactive compounds of cocoa hull were protected better in spray dried liposomes compared with secondary liposome, spray dried CHWE and freeze dried CHWE. The cocoa hull waste contained both flavon-3-ol monomers, flavan (quercetin) and phenolic acids. The interaction of these compounds with carbohydrate and oil bases molecules was an important parameter of their degradation level and bioavailability. In addition, the content and location of them in liposome structure (interior or surface) is another factor to determine the protection degree. According to these datas, the ayran (drinking yoghurt) was enriched with both encapsulated and unencapsulated cocoa phenolics which extracted from cocoa hull waste. To determine the protection level of liposomes and their effect of bioaccessibility; freeze dried cocoa hull waste extract (CHWE), spray dried CHWE, chitosan coated liposome (secondary liposome) with CHWE and spray dried chitosan liposome with CHWE were used for fortification. Protection of bioactive compounds which were total phenolic compound (TPC), total antioxidant compound (TAC) and total flavonoid compound (TFC) in fortificated ayran (drinking yoghurt) samples was investigated before and after in-vito digestion during the shelf-life period (1st, 5th and 10th and 15th day) at 4oC storage temperature. Spray dried liposome showed the highest protection level of phenolic compounds both before and after in-vitro digestion which were at least 2 times and 5 times higher than ayran (drinking yoghurt) with freeze dried CHWE before and after in-vitro digestion, respectively. The bioavailabilty of CHWE phenolics in ayran (drinking yoghurt) were increased at least 7 folds when they are added with spay dried liposomes, instead of freeze dried CHWE. The CHWE phenolic profile of ayran samples were identified by UHPLC, and determined these compounds in ayran samples during shelf-life period. The spray dried liposomes showed the better protection of all phenolic compounds in ayran during shelf life period. In addition, liposomal systems showed the better protection level of phenolics both before and after in-vitro digestion. The surface charge of liposomes and their interaction of other food components, especially ayran proteins was an important parameter for liposome stability, as spray dried liposomal systems provided higher protection of phenolics compared with secondary liposomes during shelf life. There are several studies about fortification of yoghurt and yoghurt products with polyphenol extracts, but using the liposomal encapsulation of polyphenols is the first study for enrichment the ayran (drinking yoghurt). In additon these is the first study about fortification of ayran, which is a traditional fermented milk beverage in Turkey and contain salts, with polyphenol extracts.Yüksek LisansM.Sc