60 research outputs found
A comprehensive numerical investigation of unsteady-state two-phase flow in gravity assisted heat pipe enclosure
No full textIn this study, thermal performance analysis of glass and copper two-phase closed thermosyphons (TPCTs) were investigated as 3D using comprehensive experimental methods and a new combined numerical model containing two stages. For this purpose, Volume of Fluid model has been used for the first 60 s, and Eulerian model has been employed after 60 s until 180 s for the first time in the literature. For the verification of this numerical analysis, the surface temperatures of TPCTs were measured at twenty different points by K-type thermocouples. The pressure change inside the pipes was measured by a vacuum manometer. A video camera was utilized to observe the change of steam and water volumes in the glass TPCT. The experimental and numerical results were also compared with each other in real-time for the first time in the literature. According to results, the numerical temperature distributions and steam volumes in TPCTs have shown a similar trend with the studies in the literature. It was observed that the maximum absolute temperature difference values in the evaporation, middle and condenser regions for TPCTs ranged from 6.81 K to 18.63 K. These values are similar to the values in the other studies. The maximum absolute temperature difference values were calculated between 12.09 K and 26.07 K for different turbulence models.Kutahya Dumlupinar University Scientific Research Projects Unit (DPU-BAP) [2017-55]; Technological Research Council of Turkey, National Scholarship Program for Ph.D. students (TUBITAK-BIDEB)This study was supported by Kutahya Dumlupinar University Sci-entific Research Projects Unit (DPU-BAP) under the grant of the project number of 2017-55. Halit Arat, 1st author, would like to thank Technological Research Council of Turkey, National Scholarship Program for Ph.D. students (TUBITAK-BIDEB) for its financial assistance during his doctoral studies
KEHIDUPAN ARAT SABULUNGAN DALAM MASYARAKAT TRADISIONAL MENTAWAI
No full textSkripsi ini berjudul “Kehidupan Arat Sabulungan dalam Masyarakat Tradisional Mentawai (Kajian Hasil Rapat Tiga Agama terhadap Perkembangan Arat Sabulungan 1954-1978)”. Penulisan skripsi bertolak dari rasa ingin tahu penulis terhadap kebudayaan masyarakat tradisional Mentawai yang hampir punah, dengan sistem religinya Arat sabulungan. Kepercayaan tersebut berlandaskan kepada alam, di mana masyarakat tradisional Mentawai percaya akan kekuatan dewa-dewa yaitu; Tai Kabagat Koat (dewa laut), Tai Ka-leleu (roh hutan dan gunung), dan Tai Ka Manua (roh awang-awang). Adapun permasalahan yang diangkat dalam skripsi ini adalah pengaruh Rapat Tiga Agama terhadap keberadaan Arat Sabulungan serta dampaknya terhadap kehidupan masyarakat tradisional Mentawai. Bagaimana kehidupan beragama masyarakat tradisional Mentawai serta perubahan yang terjadi pada masyarakat Mentawai. Untuk memfokuskan penelitian, penulis merumuskan empat pertanyaan sebagai berikut: (1) Bagaimanakah kehidupan Arat Sabulungan dalam masyarakat Mentawai sebelum Rapat Tiga Agama?(2) Apa yang melatarbelakangi diadakannya Rapat Tiga Agama?(3) Bagaimana peran pemerintah dalam pelaksanaan Rapat Tiga Agama?(4) Bagaimana Pengaruh Rapat Tiga Agama terhadap Arat Sabulungan dalam Masyarakat Mentawai? Dalam penelitian ini, metode yang digunakan adalah metode historis yang meliputi pengumpulan sumber (dalam hal ini sumber tulisan), kritik sumber, interpretasi dan historoigrafi. Dalam melakukan penelitian ini, penulis menitikberatkan pada sumber tertulis, mengingat sangat teerbatas waktu dan lain hal maka peulis tidak dapat melakukan penelitian langsung ke Kepulauan Mentawai. Adapun hasil penelitian ini menunjukkan bahwa kepercayaan yang dianut masyarakat Mentawai adalah Arat Sabulungan. Arat Sabulungan ini mengatur hidup masyarakat Mentawai dalam satu kesatuan yang disebut uma. Uma juga merujuk pada rumah besar, di mana dalam uma dilakukan segala aktifitas yang berkaitan dengan Arat Sabulungan, yang semua aktifitasnya. Mereka hidup bersahaja dengan mengandalkan alam untuk memenuhi kebutuhan mereka. Seluruh ktifitas mereka dipimpin oleh ketua adat yang disebut Rimata dan Sikerei. Kemudian, keberadaan Arat Sabulungan mulai hilang secara berangsur-angsur akibat dari diadakannya Rapat Tiga Agama (Islam, Protestan dan Sabulungan) dengan bantuan Pemerintah melalui SK No. 167/PROMOSI/1954. Kebudayaan Mentawai merupakan kekayaan budaya bangsa sebagai warisan bagi generasi berikutnya. Suatu keyakinan yang tetap menjaga dan menyeimbangkan kehidupan masyarakat Mentawai, baik dengan sesama manusia maupun dengan alam, yang mulai tergerus oleh kemajuan jaman dan kebutuhan akan ekonomi tunai. Sebelum diadakannya Rapat Tiga Agama, kehidupan masyarakat Mentawai hidup dengan sesama masyarakat dan juga menajga kelestarian alam. Kemudian datangnya orang-orang luar pulau mengkibatkan kontak budaya dan secara perlahan terjadi perubahan. Namun, ketidaksabaran para pendatang memunculkan pemikiran untuk mengubah tatanan kehidupan sosial-budaya masyarakat Mentawai secara paksa melalui Rapat Tiga Agama. Dengan instan mengubah tatanan kehidupan masyarakat Mentawai, terutama mengubah sistem religinya. Menghilangkan Arat Sabulungan dan menggantinya dengan agama resmi yang diakui oleh pemerintah. Perubahan dalam sistem religi ini kemudian menyebar pada berubahnya sistem sosial-budaya masyarakat Mentawai. Mengakibatkan terkikisnya budaya lokal yang tergerus modernisasi, yang kemudian hampir dan bahkan dilupakan oleh generasi muda masyarakat Mentawai.
This titled " Life Arat Sabulungan in Mentawai Traditional Society ( Study Results Meeting of the Three Religions of the Progress Arat Sabulungan 1954-1978 ) ". Contrary thesis of curiosity author of the culture of traditional societies Mentawai endangered , with its religious system Arat Sabulungan . The belief is based on nature, where traditional Mentawai people believe in the power of the gods namely ; Tai Kabagat Koat (god of the sea), Tai Ka - leleu ( spirit forests and mountains ), and Tai Ka Manua (spirit of the clouds). The issues raised in this paper is the influence of the Meeting of the Three Religions Arat Sabulungan existence and its impact on traditional Mentawai people's lives. How Mentawai traditional religious communities as well as the changes that occurred in the Mentawai people. To focus the study, the authors formulate the following four questions: (1) How is life in the Mentawai people Arat Sabulungan before the Meeting of the Three Religions? (2) What is behind the holding of the Meeting Three Religions? (3) What is the role of government in the implementation of the Meeting of the Three Religions? (4) How to Influence Meeting of the Three Religions of the Arat Sabulungan in Mentawai Society? In this study, the method used is the historical method that includes collection source (in this case the source text), source criticism, interpretation and historoigrafi. In conducting this study, the authors focused on written sources, given the very teerbatas time and other things it can not do research peulis directly to the Mentawai Islands. The results of this study indicate that the beliefs held Mentawai people are Arat Sabulungan. Arat is set Sabulungan Mentawai people live in one unit called uma. Uma also refer to the big house, where the uma do all the activities related to Sabulungan Arat, who all activities. They rely on a simple life with nature to meet their needs. The whole ktifitas them led by traditional leaders called Rimata and Sikerei. Then , the existence of Arat Sabulungan began to disappear gradually as a result of the holding of the Meeting three religions (Islam, Protestantism and Sabulungan) with the help of the Government through Decree No. 167/PROMOSI/1954. Mentawai culture is the cultural wealth of the nation as a legacy for the next generation. A belief that while maintaining and balancing the life of the Mentawai people, both with fellow human beings and with nature, which began to be eroded by the progress of time and the need for cash economy. Prior to the Meeting of the Three Religions, Mentawai people live life with other people and also menajga nature. Then the guys come from outside the island 's dance culture contact and change is slowly happening. How ever, the impatience of the newcomers bring ideas to change the order of the socio-cultural life of the Mentawai people forced by Meeting Three Religions. Instantly change the order of the Mentawai people's lives, especially change its religious system. Arat Sabulungan eliminate and replace it with an official religion recognized by the government. Changes in the religious system and then spread to the changing socio-cultural system of the Mentawai people. Resulted in the erosion of local culture that eroded modernization, and even then almost forgotten by the younger generation of the Mentawai people
Epitome and translation with commentary of Kad?n Sorunu (The status of women) by Necla Arat
No full textMaster of EducationThe status, achievements and problems of women have been examined comprehensively in recent years by numerous research projects, conferences and seminars globally. As it was indicated in the introduction of the book entitled "Kadin Sorunu" (The Status of Women) which is the subject of this thesis, the author Dr. Necla Arat who was then a lecturer at the Faculty of Arts, Department of Philosophy of Istanbul University has done minor research and expanded it as a printed text with the abovementioned title. Though the book was written in 1975, due to various reasons and difficulties, it was published in 1980, revised and, enlarged edition was printed in 1986 (Say Yayinlari, Istanbul). The first edition had aroused a great deal of interest, it was criticised in positive and negative ways, such as a "complete political booklet", "a study of democratic leftists and progressives that reflect the contradictions of the Republican era woman". The author expresses her satisfaction with the outcome of her work, her book has not faded away in silence. She insists in her book that it is the responsibility of women themselves to
defend vigorously their rights.
Dr. N. Arat has published a number of books and
translated some texts. Presently, she is the head of the
Department for Women's issues of Istanbul University.
A. Language
B. Women and social change in Turkey
C. Islam
The text has three parts. Part I is an account of Western feminism and the struggle for women's emancipation. The author contributes valuable data on the historical background of the emancipation of Western women and the status of women before Islam. However, the other parts of the text which examine women under the influence of Islam and in the Republican era require comment
Load-sensing Based Integrated Chassis Control: Using hierarchical strategy and control allocation
No full textEvolution of new technologies, market preferences and vehicle safety standards and regulations motivate the automotive industry to contribute to higher quality mobility and safer transportation for the society. With the compelling development of electronics over the past few decades, passenger cars are equipped with an increasing number of active safety systems, and even the fitment of some of those has become mandatory in regulations, such as ABS (Anti-lock Braking System) and ESC (Electronic Stability Control). As a result, the integration becomes necessary to meet the fast introduction of new functionality and to supervise and manage different variety of controllable vehicle subsystems, attracting the interests from both the industry and the academia. Numerous studies have proven integrated chassis controls to have incomparable advantages in multiple-objective performance improvement, hardware complexity and system costs reduction, interference prevention, system reliability and fault-tolerant capability. Among the previously explored integrated control architectures, hierarchical strategy is considered the most proper one, as it allows the cooperated development between OEMs and suppliers and make good use of existing subsystems. Within this context, this study proposes a novel adaptive wheel force feedback control allocation algorithm utilizing SKF load sensing bearing technology, to coordinate ABS, ESC and AFS (Active Front Steering). It aims to investigate a real-time implementable framework which is open to the extensions and integration of other load-sensing based control subsystems. The proposed approach is validated and evaluated by open-loop and driver-in-the-loop tests performed on multi-body vehicle model in Simulink-CarSim co-simulation.Control EngineeringDelft Center for Systems and ControlMechanical, Maritime and Materials Engineerin
Model sensitivity analysis of Monte-Carlo based SEM simulations
No full textThe sensitivity of simulated scanning electron microscopy (SEM) images to the various physical model ingredients is studied using an accurate, but slow simulator, to identify the most important ingredients to include in a reliable and fast SEM image simulator. The quantum mechanical transmission probability (QT) model and the electron-acoustical phonon scattering model are found to have the most significant effect on simulated 2D and 3D metrology results. The linewidth measurement error caused by not including these models in the simulation is less than 2 nm. Specifically, it was found from a comparison to experimental data that the QT model is essential in accurately predicting particular signal features in linescans such as “shadowing”. The simulator is compared with two other publicly available simulators, JMONSEL and CASINO, where the first one is also based on first-principle physics models and the latter one is using phenomenological models. CASINO is the fastest simulator on CPU, but Nebula on GPU is two orders of magnitude faster compared to a single threaded CPU simulation. Only up to 6% speed increase has been achieved by different model choices.ImPhys/Microscopy Instrumentation & Technique
Electric power steering: Recreating steering feel
No full textApplication of electronics in the automotive industry is extensively spreading. Electric power steering is hereby an exciting improvement to steering systems since the introduction of hydraulic power steering systems, which was first introduced as early as 1970s. Drivers desire hydraulic power steering behaviour because of its natural feel while providing assistance, but it has many disadvantages such as component lifecycle, oil leaks and power consumption. The use of electronic power steering provides the opportunity to remove such problems associated to hydraulic power steering and introduce benefits in terms of adaptability, comfort and safety. Since today's vehicles are making use of the by-wire technology for most components in the car, the additional electronic power steering will make it possible to have a full range of automated driving aids. Even though electric power steering comes with many advantages, there are still some disadvantages which are mentioned in numerous articles. These problems are mostly described as a lack in steering feel. More precisely it's described as if the front wheels are disconnected from the ground wheels. Many studies show different algorithms to minimise this, however it can be seen that even in the most successful products there is some complaint about this. An important tool to analyse this problem is the use of driving simulators. The implementation of a steering model that maintains high fidelity dynamics will bring many advantages. At the moment steering systems are developed by vehicle testing which is considered expensive and time consuming. The study of steering models will give more insight for the development in steering systems and the implementation in a HIL-simulator will ease the process of steering system development. This thesis will show the implementation of a steering model in a high fidelity steering simulator and it will propose a different method for solving the problem of steering feel loss. Finally it will conclude with driver in the loop experiments to show and evaluate the proposed method.Delft Center for Systems and ControlMechanical, Maritime and Materials Engineerin
DÖNER TEPSİLİ KABİN TİPİ KURUTUCUDA KAVUNUN KURUMA KARAKTERİSTİĞİNİN İNCELENMESİ
No full textBAP 2018-02Son yıllarda organik olarak yetiştirilen meyve ve sebzelere olan ilginin artmasıyla bu ürünlerin doğal yöntemlerle yetiştirilmediği dönemlerde kurutulmuş olarak tüketilmesi oldukça fazla talep görmeye başlamıştır. Bu çalışmada, döner tepsili kabin tipi kurutucuda farklı parametreler kullanılarak kavunun kuruma karakteristiği deneysel olarak incelenmiştir. Farklı kurutma havası sıcaklığında yapılan deneylerde 10 mm kalınlığındaki kavun dilimleri kullanılmıştır. Döner tepsili kabin kurutucuda deneysel çalışmalar 2 m/s kurutma hava hızında ve 63 oC, 68 oC ve 73oC kurutma havası sıcaklıklarında gerçekleştirilmiştir. Ayrıca yapılan diğer deneysel çalışmalarda, en yavaş kurumanın gerçekleştiği 63 oC için 1.6 m/s, 1.7 m/s ve 1.8 m/s kurutma havası hızlarının kuruma süresine etkisi ve 73oC kurutma havası sıcaklığı için farklı kalınlıkların kuruma süresine etkileri incelenmiştir. Deneysel çalışma sonucu kurutma havası sıcaklıklarının kurumaya olan etkisi araştırılmıştır. Ele alınan parametrelerinin incelenmesi sonucunda, sıcaklığın artmasıyla kuruma sürelerinde önemli ölçüde azalma meydana gelmiştir.Kütahya Dumlupınar Üniversites
Assessment of Total Operating Costs for a Geothermal District Heating System
No full textInternational Conference on Energy and Management - JUN 05-07, 2014 - Istanbul Bilgi University, TURKEYWOS: 000380565300028District heating system (DHS), especially geothermal, is an important class of heating, ventilating, and air conditioning systems. This is due to the fact that in many countries and regions of the world, they have been successfully installed and operated, resulting in great economic savings. In recent years, such systems have received much attention with regard to improving their energy efficiency, equipment operation, and investment cost. Improvement in performance of a geothermal district heating system (GDHS) is a very effective mean to decrease energy consumption and to provide energy saving. To perform the potential energy savings in a GDHS, the advanced exergoeconomic analysis is applied to a real GDHS in the city of Afyon/ Turkey. Then, it is evaluated based on the concepts of exergy destruction cost and investment cost. The results show that the advanced exergoeconomic analysis makes the information more accurate and useful and supplies additional information that cannot be provided by the conversional analysis. Furthermore, the Afyon GDHS can be made more cost effectiveness, removing the system components' irreversibilities, technical-economic limitations, and poorly chosen manufacturing methods.Istanbul Bilgi Univ Dept Energy Systems Eng
Experimental study on heat transfer characteristics of closed thermosyphon at different volumes and inclination angles for variable vacuum pressures
No full textIn this study, the thermal performance of vacuumed copper pipe has been experimentally investigated by using different volume values of 5 ml, 10 ml, 15 ml, and 20 ml with inclination angles of 45°, 60°, and 90° for variable vacuum pressures. For this purpose, the inner, outer diameter, and length of the vacuumed pipes filled with the distilled water were 26 mm, 28 mm, and 1500 mm, respectively. This copper pipe was vacuumed until the absolute pressure of 6.32 kPa and immersed in a heat source at a constant temperature of 82°C at the beginning of the experiments. The surface temperatures of the vacuumed pipes were measured at twenty different points by using K-type thermocouples in two different data loggers. All calculations were performed as variable saturation temperatures at variable vacuum pressures with changing the time. According to the results, the experimental boiling heat transfer coefficients showed a good agreement with the correlations in the literature. Also, the best thermal resistance was obtained in the vacuumed copper pipe with a water volume of 10 ml at the inclination angle of 90° until the end of the experiment
Simulation of Electron-Matter Interaction in Electron Beam Lithography and Metrology
No full textIntegrated circuit (IC) technology lies at the heart of today’s digital world. The immense amount of computational power that came along with the downscaling of circuits allowed us to place faster and smaller chips almost everywhere. However, with today’s requirements, even a one-nanometer error on those chips can drastically change the performance of the chip. Therefore, maintaining product quality is challenging, and more accurate techniques are needed to manufacture future generation chips. Electron beam based techniques are known to provide very high resolution both in production and testing of these chips. However, the ongoing trend is also challenging the established e-beam technologies. Two common problems in both imaging and lithography are addressed in the thesis. One of them is the emerging importance of the 3rd dimension (3D) in imaging and lithography. The other one is the notorious charging effect when the samples involved, such as gate oxides, are not sufficiently electrically conductive. The experimental trial and error approach to understand and solve these problems is too time-consuming and can also be very expensive. Therefore, tools such as Monte Carlo simulations are needed that aid in getting a better fundamental understanding of these issues. The development of a simulator that can help to find solutions for the problems above is one of the primary objectives of this thesis.ImPhys/Microscopy Instrumentation & Technique
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