68 research outputs found
Surface-charge effects on the electro-orientation of insulating boron-nitride nanotubes in aqueous suspension
No full textThe alignment of hexagonal boron-nitride nanotubes (BNNTs) in aqueous KCl solutions under spatially uniform electric fields was examined experimentally, using direct optical visualization to probe the orientation dynamics of individual BNNTs for different electric-field frequencies. Different from most previously studied nanowires and nanotubes, BNNTs are wide-bandgap materials which are essentially insulating at room temperature. We analyze the electro-orientation of BNNTs in the general context of polarizable cylindrical particles in liquid suspensions, whose behavior can fall into different regimes, including alignment due to Maxwell-Wagner induced dipoles at high frequencies, and alignment due to fluid motion of the electrical double layer around the particles at lower frequencies. For BNNTs, the variation of the crossover frequencies in the electro-orientation spectra was studied in electrolytes of different conductivity. The effect of BNNT surface charge on electro-orientation was further studied by changing the pH of the aqueous solution. We find that the electric-field alignment of the BNNTs in the low-frequency regime is associated with the charging and motion of the electrical double layer around the particle. However, as BNNTs are non-conducting particles, the reasons for the formation of the electrical double layer are likely to be different than that of conducting particles. We discuss two possible mechanisms for the double-layer formation and alignment of 1D dielectric particles, and make comparison to those for the more commonly studied conducting particles.Peer reviewe
Comparision of the anti-immigrant sentiment in Turkey and Europe, specifically Syrian asylum seekers
No full textİnsanlık tarihi kadar köklü ve kadim bir geçmişe sahip olan göç olgusu; ekonomik, sosyal, kültürel ve politik bir mesele olduğu kadar, güvenlik konularını da yakından ilgilendiren çok boyutlu bir meseledir. II. Dünya Savaşı'ndan sonra dünyada yoğunlaşan uluslararası nitelikteki göç hareketleri ile özellikle Arap Baharı olarak adlandırılan ve başta Türkiye ve Avrupa olmak üzere bütün dünyayı etkisi altına alan uluslararası göç hareketlerinden sonra yaşadığımız dönem, 'Göç Çağı' olarak adlandırılmaya başlamıştır. Nitekim Birleşmiş Milletler verilerine göre, uluslararası göçün son otuz yıldaki hızıyla devam etmesi durumunda, 2050 yılına gelindiğinde uluslararası göçmenlerin sayısının 405 milyona ulaşması beklenmektedir. Göç olgusunun bu dinamik yapısı, dünya çapında hükûmetlerin kamu dinamiklerinden istihdam ve eğitim politikalarına, altyapı yatırımlarından sağlık harcamalarına kadar neredeyse toplumsal hayatın bütün alanlarında sürdürülebilir politikalar hayata geçirmelerini gerekli kılmaktadır. Göç konusunda son dönemlerde öne çıkan, kritik önemi haiz meselelerden biri de ulus devletlerin deneyimledikleri 'entegrasyon ve uyum sorunları'dır. Özellikle Avrupa'da dönemsel olarak tırmanan terör eylemleri, artan ekonomik sorunlar, işsizlik, yüksek enflasyon gibi sorunların yanı sıra suç, istihdam darlığı, demografinin dönüşümü ve ulus devlet bilincinin zarar görmesi gibi tehditlerin sorumlusu olarak ilk akla gelen göçmenler olmuştur. Bu bağlamda bu çalışmanın amacı, Suriyeli göçmenler özelinde ortaya çıkan göçmen karşıtlığı konusunu Türkiye ve Avrupa üzerinden karşılaştırmalı olarak analiz etmektir. Literatürde göçmen karşıtlığı, kavramsal olarak, bir menşe ülkeden başka bir ülkeye giden göçmenlerin bir açıdan veya topyekûn olarak reddedilmesi veya kabul edilmemesi durumu olarak tarif edilebilir. Göç alan birçok ülkede neredeyse kolektif bilincin parçası haline gelen göçmen karşıtlığı, sonuçları itibariyle hem göç alan ülkeleri hem de göçmenleri önemli ölçüde etkilemektedir. Zira göçmenler, gettolaşma ve mekânsal ayrıksılaşmalar yoluyla kültürel ve ekonomik izolasyona maruz bırakılabildikleri gibi; işsizlik, yoksulluk, kimlik sorunları ve sınır dışı edilme tehdidiyle karşı karşıya kalabilmektedirler. Öte yandan göçmen kitleler de, gittikleri yerlerde şiddetli hasımlık eğilimlerine maruz kaldıkları psikolojisi üzerinden, saldırganlık, kuralsızlık gibi anomik haller içine girebilmektedirler.The phenomenon of migration, which has a history as deep and ancient as human history, is a multidimensional issue that closely concerns the security issues, as well as being an economic, social, cultural, and political issue. The period we go through after the international migration movements that intensified in the world after the World War II and especially after the so-called Arab Spring which affected the whole world, especially Turkey and Europe; began to be called the 'Age of Migration'. As a matter of fact, according to United Nations data, if international migration continues at the same rate as in the last thirty years, the number of international immigrants is expected to reach 405 million by 2050. This dynamic structure of the migration phenomenon requires the governments around the world to implement sustainable policies in almost all areas of social life, extending from the public dynamics to the employment and education policies, from the infrastructure investments to the health expenditures. One of the critically important issues that has come to the fore recently regarding migration is the "integration and adaptation" problems that the nation states go through. Especially in Europe, immigrants are the first to come to mind as responsible for problems such as periodically escalating terrorist acts, increasing economic problems, unemployment, high inflation, as well as threats such as crime, employment shortage, transformation of demography and damage to the nation-state consciousness. In this context, the aim of this study is to comparatively analyze with reference to Turkey and Europe, the issue of anti-immigrant sentiment which has emerged in relation to the the Syrian immigrants specifically. In the literature, anti-immigrant sentiment can be conceptually defined as the rejection or non-acceptance of immigrants moving from one country of origin to another country, in some respect or in whole. Anti-immigrant sentiment, which has almost become part of the collective consciousness in many immigrant-receiving countries, significantly affects both immigrant-receiving countries and immigrants. Because immigrants may be exposed to cultural and economic isolation through ghettoization and spatial segregation, as well as face unemployment, poverty, identity problems and the threat of deportation. On the other hand, immigrant masses may enter into anomic states such as aggression and normlessness due to the psychology of being exposed to violent hostile tendencies in the places they go to
Author lexicography and a theoretical evaluation on author dictionaries prepared in Turkey
No full textBatı literatüründe "author lexicography" ve "writer lexicography" ve Rus sözlükçülük geleneğinde "pisatel'skaya leksikografiya" ve "avtorskaya leksikografiya" adlandırmalarıyla karşılanan yazar sözlükleri hem dünyada hem de Türkiye'de birçok örneği olan genel sözlük tipolojisinde bir alt tür olarak yer alan sözlük türüdür. Genel sözlük tanımlarından ve uygulamalarından farklı olarak "yazar sözlükleri"yle ilgili birbirinden farklı özellikte uygulama örneklerinin yaygınlaşması bu uygulama alanıyla ilgili teorik çalışmalara da bir ihtiyaç olduğu gerçeğini ortaya koymuştur. İşte bu ihtiyacı karşılamak amacıyla yazar sözlüklerinin tarihi, amaçları, yöntemleri, makro ve mikro yapısı, tipolojisi gibi konular üzerine Türkiye dışında birçok çalışma yapılmış, teoriler, yöntemler belirlenmeye çalışılmıştır. Türkiye'de de birçok yazar sözlüğü örneği bulunmakla birlikte hem adlandırmayla ilgili birtakım karışıklıkların hem de uygulamada birtakım sorunların olduğu görülmektedir. Türkiye'deki yazar sözlüğü uygulamalarıyla ilgili bu belirsizliğe sebep olarak da yazar sözlüğünü oluşturan bileşenlerin belli bir parametreye sahip olmaması görülmektedir. Bu tez çalışmasında öncelikle Türkiye dışındaki yazar sözlüğüyle ilgili teorik çalışmalar incelenmiş, ardından hem Batı'daki yazar sözlüğü örnekleri hem de Türkiye'deki uygulamalar incelenerek yazar sözlüklerinin mega, makro ve mikro yapıları oluşturulmaya çalışılmıştır.
Author dictionaries, which called "author lexicography" and "writer lexicography" in Western literature and "pisatel'skaya lexicographyya" and "avtorskaya lexicography" in the Russian lexicography tradition, are a type of dictionary that is included as a subgenre in general dictionary typology, which has many examples both in the world and in Turkey. Unlike general dictionary definitions and applications, the spread of application examples with distinctive characteristics related to "author dictionaries" has revealed the fact that there is a need for theoretical studies related to this field of application. To meet this need, many studies have been carried out outside Turkey on topics such as the history, purposes, methods, macro and microstructure, typology of author dictionaries, and theories and methods have been tried to be determined. Although there are many examples of authors' dictionaries in Turkey, it is seen that there are some confusions about naming and some problems in practice. The reason for this uncertainty about the author dictionary practices in Turkey is that the components that make up the author dictionary do not have a certain parameter. In this thesis study, firstly, theoretical studies related to the author dictionary outside Turkey were examined, then both the examples of author dictionaries in the West and the practices in Turkey were examined to create mega, macro and microstructures of author dictionaries
To what extent may the unfavorable viewpoints of critics on E. A. Poe's use of horror and social satire in his stories be refuted by examples from and analysis of the author's eight short stories?
No full textWith numerous short stories and poems, Edgar Allan Poe is considered to be the piquant and
astounding milestone of the American Literature. Yet, his style and achievements have always
been interpreted antagonistically by large numbers of critics. This study analyzes the features
unique to Edgar Allan Poe in his short stories “Murders In The Rue Morgue”, “The Fall of
The House of Usher”, “A Tale of Jerusalem”, “The Pit and The Pendulum”, “The System of
Doctor Tarr and Professor Fether”, “A Cask Of Amonillado”, “The Masque of Red Death”
and “The Man That Was Used Up” while refuting to chosen examples of negative reviews
about Edgar Allan Poe.
Due to the fact that Edgar Allan Poe is well-known for his usage horror, satire, humor and
fiction in his short stories, these qualities have been criticized mostly by many writers and
philosophers as well. In this sense, the scope of the study will be sharpened on how these
techniques are used in his short stories to make them nonpareil and what was Edgar Allan
Poe’s authorial intention while utilizing these attributes in his works. At this point the analysis
of the characters, themes and plot will be prioritized compared to the language and style that
Edgar Allan Poe uses in his texts.
Since the criticism against Poe focus on the usefulness of such features in his short stories and
how they intimidate the reader from the text, the study proves that the gap between Poe and
the reader is a simple issue of reciprocal misunderstanding which is proven to be artificial and
bogus with examples and facts from his short stories
Designing preservation. Integrating the architectural project to UNESCO tools to tackle territorial fragility: the Tivoli case as a pilot experience
No full textThe research investigates the potential contribution of a design-based approach to the current institutional UNESCO safeguard tools concerning the relation core/territory, challenging the conservative role of buffer zones that lead to stalemate situations in terms of territorial development, especially in the Italian context. Through the analysis of case studies, a methodological approach is developed that focuses on the one hand on the use of design tools for the assessment of heritage-related territories (cognitive framework), and on the other hand on the use of design actions in the management strategies for valorisation (interpretation framework). These tools are tested on the relevant experimental case of Tivoli, seat of two major World Heritage sites, as a pilot experience of integration of design tools in safeguard and management strategies for the solution of territorial fragility in complex heritage-related contexts
Modeling Morphodynamic Processes in Meandering Rivers with UAV-Basedmeasurements
No full textAkay, Semih Sami (Arel Author)Accurate surface models are a crucial component of studies of morphodynamic modeling of rivers and river channel evolution. The high flows that rivers have are caused by changes in flood bed or low canal flow, also it changes river channel morphology. Floods that occur during the spring months cause significant geomorphological changes. In addition to this, low flows during the summer also trigger erosion and superficial accumulation in the ongoing process. Using an accurate, high-resolution, seamless surface models of the river channel and floodplain allows to detect morphological changes of the whole river channel more accurately than using traditional methods. This enables a more comprehensive view of the riverbed evolution. Therefore, high-quality topographical data at different scales are required to study fluvial processes and river dynamics. Nowadays, a combination of photogrammetry and Unmanned Aerial Vehicle (UAV) systems is widely used for various applications, especially for 3D surface modelling and large scale mapping. UAV systems offer many advantages in terms of cost and image resolution when compared to terrestrial photogrammetry and satellite remote sensing systems. In the study, aerial imaging was carried out via UAV to produce very high resolution surface models based on Structure from Motion (SfM) technique. Multi-temporal topographic data were produced and morphodynamic processes in the Buyuk Menderes River were modeled. Thus, UAV-based a fast and practical way to derive volumetric quantity of lost/gained soil was developed
Non-emergency Patient Transfer Scheduling and Assignment
No full textEmergency Medical Services organizations are responsible for providing paramedic crews, vehicles and equipment to transfer patients from one location to another in emergency and non-emergency settings. They must solve difficult scheduling and assignment problems to ensure on-time arrival of patients and the efficient use of health care resources during non-emergency operations. Ambulances can serve both emergency and non-emergency requests but are rarely available to serve non-emergency requests. Therefore, non-emergency requests are the responsibility of Patient Transfer Units. The objective of this study is to develop a mathematical model that will assign Patient Transfer Units to non-emergency patient transfer requests, design a schedule that will minimize travel costs and balance workloads and apply it to a real-world case study. This paper also proposes a framework to utilize historical patient transfer data in the scheduling process. The mathematical model provides decision support for the non-emergency patient transfer scheduling process.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Discrete Mathematics and Optimizatio
The theory of n-scales
No full textWe provide a theory of n-scales previously called as n dimensional time scales. In previous approaches to the theory of time scales, multi-dimensional scales were taken as product space of two time scales [1, 2]. n-scales make the mathematical structure more flexible and appropriate to real world applications in physics and related fields. Here we define an n-scale as an arbitrary closed subset of R-n. Modified forward and backward jump operators, Delta-derivatives and Delta-integrals on n-scales are defined
Marchenko Inversion
No full textMarchenko inversion is a new way to invert seismic or electromagnetic data recorded during geophysical surveys. The inversion method uses Marchenko theory. This is a recent development which enables the retrieval of Green's functions at any place in the subsurface. A non-recursive Marchenko inversion method has already been introduced but in this thesis a recursive Marchenko inversion method is implemented and analysed. A recursive scheme lies at the center of this new method. In this thesis, the new method is implemented and tested on a 1D subsurface model. The recursive scheme is first validated. This is done by computing a reflection response with it and comparing it with a reflection response resulting from forward modeling. After this, the accuracy of retrieved local reflection coefficients from the recursive inversion method is determined. This is done by comparison with exact reflection coefficients of the subsurface model. After this, several different parameters of the used subsurface model, data computation and the recursive inversion method itself are investigated for their influence on the accuracy of the inversion method. In particular interest is the effect of interval time errors because these result in errors that can build up rapidly through the recursion. However, the method has a big advantage. It is shown that the recursive Marchenko inversion method has a way to retrieve the magnitude of made interval time errors and correct for these when interval times are overestimated. In this way the error build up is stopped. In the end, it is shown that the new method delivers high accuracy results and has an advantage in computational expense compared to the existing recursive Marchenko inversion method. It is concluded that the new method shows promising prospects and that it is worthwhile to investigate the method further.Applied Geophysics | IDEA Leagu
Alternating Follow-the-Leader Medical Device with Pneumatically Actuated Shape Locks
No full textDevelopments in minimally invasive surgery such as natural orifice transluminal endoscopic surgery and single port laparoscopic surgery have pushed medical devices to be higher articulated and more dexterous. These surgery methods have proven to greatly decrease bleeding, scar tissue, hospital time, and cost. The procedures involve the navigation of flexible instruments through tortuous anatomical pathways. To reduce chances of tissue damage it is desired to reduce the interaction with anatomical structures during the trajectory. To realize this aspect a so-called Follow-the-Leader (FTL) motion has been adapted as a design feature for medical devices. This motion allows for the shaft of the instrument to conform to the shape taken by its end-effector without relying on anatomical reaction forces. One strategy to achieve FTL motion is the so-called alternating advancement where two shafts subsequently switch from flexible to stiff in order to conserve the configuration of the shaft. These devices have been shown to possess relatively many degrees of freedom for a small number of actuators which can greatly reduce the cost of the device. A state-of-the-art analysis has shown that, despite the kinetic advantages, there are no alternating FTL devices that use pneumatically actuated shape locks to constrain the flexibility of the shaft. In this work an alternating FLT medical device with pneumatically actuated shape locks was designed, produced, and tested. The device has a diameter of 40 mm and nine degrees of freedom. The total bending angle is 90 degrees with a bending radius of 85 mm. The device leaves room for improvement but does show that two concentric shafts can be shape locked pneumatically to perform an alternating FTL motion.Mechanical Engineerin
- …
