Specially designed non-damaging lost circulation pills (LCP) are being effectively applied for drilling depleted zones worldwide. Optimizing the LCP compositions stop the lost circulation effectively and protect the production zone from liquid and solids invasion significantly. Shape, particle size distribution and concentration of the lost circulation materials (LCM) are key parameters determining the effectiveness of LCP. In this study, the Permeability Plugging Apparatus (PPA) is utilized to evaluate effectiveness of various LCM&rsquo / s in curing the lost circulation. Sized calcium carbonates are used as LCM in different concentrations and in different particle size distribution. Lost circulation zones are simulated using the ceramic disks and slotted disks. Ceramic disks with nominal pore sizes 20, 35, 60, 90, and 150 microns are characterized in terms of pore size distribution using the computerized image analysis technique. Filter cake quality, spurt loss and filtrate volume are basic parameters to be evaluated in this study. Tests are performed at 75 F and 300 psi of differential.

Founded by individuals for religious and charity purposes, the Vakif institution was the main institution in the construction and conservation of the built environment in the Ottoman period. Religious, charitable, municipal, educational, social and health services were provided by spaces such as k&uuml / lliyes, mosques, medreses, hans, baths, shops, etc. which were built through the Vakif Institution. As the underlying concept of the vakif institution was serving forever, the repair of these spaces &ndash / the vakif buildings &ndash / was accepted as a fundamental issue for ensuring the functionality and continuity of the vakif. With this aim, vakif institution set the legal, administrative, technical and financial bases for the continuity of the system within its autonomous and local structure in the classical Ottoman period. With the westernization movements in the Tanzimat era, vakifs were gathered under a central institution called Evkaf Nezareti, which had a central budget and administrative structure. In the Republican period, the General Directorate of Pious Foundations (GDPF) took this centralized institutional structure as it was and since then GDPF has been the heir of the vakif institution and vakif heritage in Turkey. However, GDPF has still not adopted an effective conservation policy. GDPF&rsquo / s attitudes towards the conservation of the vakif cultural properties are far from the understandings of the classical vakif system. Briefly, the change of the main concept of the vakif system after the classical Ottoman period can be considered as the main reason for the increased number of vakif buildings in ruinous state. From this perspective, this thesis aims at forming a model mainly based on adapting the positive aspects of the classical vakif system into the GDPF&rsquo / s conservation mechanism of vakif-based immovable cultural properties. The focus is given on the examination and comparison of the vakif system&rsquo / s past and present attitudes towards sustainable conservation. In this line, it is aimed to adapt the vakif systems&rsquo / applicable legal, administrative and financial approaches towards the conservation to GDPF within the limits of the current administrative and legal system. At another level, the functionality of the proposed model forming of the necessary administrative and legal arrangements is given importance.

In this work, we investigate the general structure and the concepts behind the contemporary electronic voting schemes, with special emphasis on voter verifiable preferential voting, homomorphic tallying and voter privacy. We firstly propose a modification in the Single Transferable Voting (STV) method to be applied to large scale elections with electoral barriers. Our proposal prevents the loss of votes and distributes them securely to the second or higher choices of their voters. This method is most suitably used in e-voting with the voter verifiable &ldquo / Pr&ecirc / t &agrave / Voter: All-In-One&rdquo / scheme that utilizes mix-networks for anonymity. We present a case study considering 2007 Turkish Parliamentary Elections to demonstrate the effect of preferential voting on the election systems that have electoral barriers. After the mathematical formulation of the election procedure, we calculate the wasted votes in 2007 elections and present simulation results for 69 election regions (that have no independent parliament members) by using a combination of &ldquo / modified STV and d&rsquo / Hondt&rdquo / methods, according to four different, politically unbiased scenarios on the distribution of secondary vote choices. Additionally, we modify the &ldquo / Pr&ecirc / t &agrave / Voter: All-In-One&rdquo / scheme by proposing three security enhancing modifications in its ballot construction phase: 1) ballot serial number, 2) digital signature of the first clerk in the mix-net, 3) different random numbers for each row of the ballot. Finally, we demonstrate the potential of multiplicative homomorphic algorithms like RSA for homomorphic tallying. The idea is based on the association of each candidate on the electronic ballot with a prime number, and unique prime factorization of the general vote product. We propose novel randomization methods for homomorphic RSA tallying, and discuss the performance and complexity of the scheme with such randomizations. Our suggestion for an auditable and verifiable e-voting scheme that employs homomorphic RSA tallying with proper randomization has advantages over El Gamal and Paillier tallying, such as having the least encryption complexity and strong anonymity resistant to unlimited computational power.

The rapid disposal of products has detrimental effects on environment which is increasing resource consumption for the production of new products, along with the waste production. Therefore, designing long lasting products has great importance for achieving sustainable consumption and production. The present study analyzes the implications of an approach called post-use design thinking for achieving sustainable consumption and production through product longevity. To explore that approach, two educational industrial design projects are analyzed throughout the study. The results suggest that post-use design thinking should be considered at the early stages of the design process. The idea generation exercises developed specifically for this design thinking seem to be helpful in generating design solutions for post-use phase. The results also indicate that the post-use design thinking is feasible in terms of design and production for glass packaging products, which is the specific case analyzed throughout the research.

In this thesis, an attitude control system based on Linear Quadratic Regulator (LQR) technique is developed for a hypothetical Earth observation satellite with a long flexible boom. To improve pointing performance of the satellite, the piezoelectric actuators are used as well. The boom is rectangular made of aluminum with the surface bonded piezoelectric layers on all four surfaces. The boom is modeled using finite elements. The pointing performance of the satellite using various metrics is evaluated through simulations. Effectiveness of the piezoelectric actuators is demonstrated.

Pyrite (FeS2) is commonly present in complex sulphide ores in significant amounts. After the enrichment of such ores by flotation, pyrite is either produced as a separate concentrate and sold to acid manufactures or removed and disposed off as tailing. Due to lack of demand from manufacturers, most of pyrites is usually disposed off as tailing. Therefore, pyrite is usually a waste from complex sulphide ores. Yet, it may be a remediation additive for calcareous soils and calcareous- alkali soils deficient in Fe and other micronutrients such as Cu, Zn and Mn. Waste pyrite may be also an alternative amendment to gypsum because of the production of sulphuric acid which is effectively used in the reclamation of calcareous alkali soils. The effectiveness of adding waste pyrite and sulphuric acid produced from waste pyrite to calcareous-alkali soil (Sarayk&ouml / y-Ankara) and calcareous soil (Gaziantep) was studied under laboratory conditions. Pure gypsum was also used as an amendment for the comparison of the effectiveness of waste pyrite in the reclamation of alkali soils. Gypsum, powder waste pyrite and sulphuric acid were applied to the soil with reference to the gypsum requirement (GR) of the soils. Greenhouse pot tests were carried out with wheat as test plant to determine the effect of waste pyrite treatment on the plant yield (wheat) and on the amount of micronutrient (Fe, Cu, Zn, Mn) essential for plant growth. Hazard potential of pyritic tailings in terms of heavy metal contamination was also taken into account. The results showed that the soil pH and exchangeable sodium percentage (ESP), indicators of alkalization, decreased upon pyrite addition to calcareous- alkali soils of Sarayk&ouml / y-Ankara. It was also found that pyritic tailings were effective in the increasing level of essential micronutrients (Fe, Cu, Zn and Mn) for plant growth in both soils. This was ascertained by the dry matter yield of the plants in the green house pot tests. Heavy metal toxicity caused by pyrite which is a rightful concern remained well below the legal limits in the soils. Thus, it was concluded that the application of pyritic tailings promoted rapid amelioration of calcareous-alkali soil (Sarayk&ouml / y-Ankara) and calcareous soil (Gaziantep) with no deleterious heavy metal contamination.

The aim of this work is to analytically treat the dynamic ion behavior during the evolution of the ion matrix sheath, considering the industrial application plasma source ion implantation for both planar and cylindrical targets, and then to de-velop a code that simulates this dynamic ion behavior numerically. If the sepa-ration between the electrodes in a discharge tube is small, upon the application of a large potential between the electrodes, an ion matrix sheath is formed, which fills the whole inter-electrode space. After a short time, the ion matrix sheath starts moving towards the cathode and disappears there. Two regions are formed as the matrix sheath evolves. The potential profiles of these two regions are derived and the ion flux on the cathode is estimated. Then, by us-ing the finite-differences method, the problem is simulated numerically. It has been seen that the results of both analytical calculations and numerical simula-tions are in a good agreement.

S'agit-il d'une banale société savante française créée en 1853, ou sa situation frontalière lui donne-t-elle un autre intérêt ? Les sept fondateurs dunkerquois, parmi lesquels le magistrat amateur de musique Edmond de Coussemaker, proche des frères Grimm, avaient à coeur de préserver les vestiges de leur langue populaire, le « flamand de France », participant au mouvement des « mémoires locales ». Ces notables, avec l'aide des curés de village, souhaitaient servir une société chrétienne, inspirée à la fois par les traditions médiévales des villes des anciens Pays-Bas reprises par la Contre-réforme espagnole et par une opposition au centralisme anticlérical hérité de la Révolution. Ils associaient la langue flamande à la religion catholique, comme éléments d'une identité française visant à se démarquer, à la fois de Paris et de leurs voisins flamands-belges, soumis eux aussi défis de la modernité. Un temps attirés par l'idéologie néogothique flamande, ils rentrent d'une façon originale, parfois douloureuse, dans le projet d'intégration des « petites patries » dans la grande, telle que le conçoit la Troisième République peu favorable à ces élites jugées réactionnaires. Durant la période de l'étude, notables ou prêtres, vont pourtant rester fidèles à leur ligne. La reconstruction de cette région, proche du front, après la Première guerre mondiale, donne au chanoine Looten, durant sa présidence de 40 ans, l'occasion de jouer très subtilement, parfois de façon ambigüe, un rôle moteur dans l'organisation d'un régionalisme typiquement septentrional ; tout en assurant la promotion de la langue populaire auprès des jeunes, notamment aux Facultés catholiques de Lille, il vise, avec son ami l'abbé Lemire, le recadrage de la religion dans le sens d'une plus plus grande transcendance et d'une plus grande ouverture au monde et aux questions sociales. / Is it a classic « learned society » created in 1853, or does its border situation provide it another interest? Edmond de Coussemaker, the music lover magistrate and the others fonders living in Dunkerque, were committed to preserving and maintaining the vestiges of their ancient vernacular, the "Flemish in France",participating in the movement of 'local memories'. These local dignitaries, with the help of village priests, wished to serve the Christian society, therein inspired both by the traditions of medieval towns of the Low Countries later on regained by the Spanish catholic reform and the opposition to anticlerical centralism inherited from the Revolution. They associated the vernacular with the catholic religion, as part of a French identity, to distinguish themselves, both from Paris and from their Belgian-Flemish neighbors, and also to submit the challenges of modernity. Once attracted by the Flemish neogothicism and neomedieval ideology, they joined, painfully for some, the integration project of "small countries" in the great nation-state, as conceived by the Third Republic, even though this regime was not favourable towards these elites which were considered reactionary. The reconstruction of this region, near the front, after the First World War, gave the canon Looten during his long presidency, the opportunity to play very subtly, sometimes ambiguously, a role in the organization of typically northern type of regionalism. While ensuring the promotion of the vernacular at the “Facultés catholiques de Lille”, with his friend Jules Lemire, he aims at driving religion in a direction of transcendence as well as larger opening to the word and its social problems.

ABSTRACT EFFECT OF INITIAL SUPPORT OF EXCAVATION ON SEISMIC PERFORMANCE OF CUT AND COVER STRUCTURES Rezaei, Hamidreza M.Sc., Department of Civil Engineering Supervisor: Asst. Prof. Dr. Alp Caner MAY 2011, 66 pages The effect of the initial support and its embedment depth, on the seismic performance of cut and cover tunnels is investigated. Cut and cover construction is one of the fastest and cheapest methods for constructing rectangular shallow tunnels. Construction of cut and cover structure in soil usually starts with installation of the initial support of excavation system, which may consists of rigid type of initial supports such as tangent piles or secant piles. These systems usually remain in place after completion of the final structure. However, to simplify the design, it is a common practice to ignore the contribution of initial support. In this study the effect of initial support of excavation on the seismic performance of cut and cover tunnels is investigated by means of a detailed dynamic finite element analysis. Three different tunnel geometries, three soil types and three acceleration histories were considered Results of the study show that depending on the soil stiffness (soft, medium, or stiff soil), the dynamic response of the tunnel deformations are affected significantly by the initial support of excavation. The effect of the initial support diminishes as the quality of the soil improves. Therefore, dynamic analyses are recommended for the final design of this type of structures especially in soft soils.

This study explores the ways in which objects are used in the organization of daily life, by specifically focusing on the use of prayer beads and their mechanical and digital variations. For this purpose, a framework based on material culture and practice theory is employed to understand how Islam informs and guides the organization and the conduct of daily life around the pervasive prayer practices, the ways objects are used for these purposes and how practices and products co-evolve by influencing each other. Fieldwork with devout Muslims, who are using prayer beads together with mechanical and digital counters for their daily praying practices, is conducted by employing ethnomethodology. Findings on the ways in which objects are used, utilized, appropriated and adopted within the socio-cultural and political dynamics of Islam in Turkey are analysed regarding the social and practical aspects of daily life such as the organization of daily life and daily practices, the core issues shaping these practices, thus objects, how identity discourse reflected on/by the use of objects and the ensemble of products that is orchestrated for a meaningful organization of daily life around prayer practices.