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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Vascular Corrosion Casts of the Spiral Valve Intestine of Siberian Sturgeon (Acipenser baerii), North American Paddlefish (Polyodon spathula) and the Yellow Stingray (Urobatis jamaicensis): A Comparative Study

Lash, Jennifer A. 01 December 2013 (has links)
Both Elasmobranchii and Acipenseriformes have a spiral intestine, developed by the intestine folding inward and twisting upon itself. A comparative analysis of the digestive system of examples of Subclass Elasmobranchii (sharks and rays) to Order Acipenseriformes (sturgeon and paddlefish) was conducted through gross dissection and scanning electron microscopy (SEM) analysis. Urobatis jamaicensis, Acipenser baerii, and Polyodon spathula were used due to accessibility. Gross dissection analysis yielded that the acipenserids have a columnar spiral valve with 8 infoldings, and U. jamaicensis has a posterior spiral valve with 13 infoldings. SEM analysis showed angiogenesis, where visible, occurred inversely with age in all species. More venous vessels were present than arterial vessels in the outer layers of the intestine, the muscularis and serosa, while the majority of the arterioles were found in the mucosa and submucosa. The vascularization pattern of the spiral valve in U. jamaicensis showed a diamond branching pattern on the surface anteriorly and posteriorly with a lateral drainage system at the midsection. Only the lateral drainage system was found in A. baerii and P. spathula. The daughter arterioles and venules to the intraintestinal artery and intraintestinal vein coincided with the turns present in the spiral valve of each species. This study suggests A. baerii and P. spathula are sister taxa and do not share a direct common ancestor with U. jamaicensis based on similarities and differences between the spiral valve vasculature.
202

Formation, Internal Support And Starbursts In Molecular Clouds

Das, Mousumi 05 1900 (has links) (PDF)
No description available.
203

Israeli-Palestinian Spiral: Compliance and Silence of Political Opinions in the Canadian Print Media

Jennings, Michelle January 2011 (has links)
The news media serve as the Canadian public’s main source of information about the Israeli-Palestinian conflict. This thesis examines the ways in which the Canadian media portray the conflict, through a lens of Habermas’ (1962) public sphere theory, Foucault’s (1926 – 1984) ideas on discourse, and Rawls’ (1921 – 2002) conceptions of equality and justice. Building on these theories, Noelle-Neumann’s Spiral of Silence theory (1974), Said’s Orientalism (1978), and d’Arcy’s (1913 – 1983) conception of the right to communicate are examined to arrive at a framework for analyzing Canadian news. Looking at ideological representations, power manifestations, issue framing, and social responsibility within the media, this thesis explores whether the Canadian media portray the conflict in such a way that fosters a downward spiral of opinions within the Canadian public. A Critical Discourse Analysis of coverage in two national English Canadian newspapers, The Globe and Mail and the National Post, during three separate timeframes of increased violence in Israel and Palestine between 2000 and 2009 reveals that newspaper representations of the Israeli-Palestinian conflict are often entrenched in predefined ways of portraying the Other, fostering an Israeli-Palestinian spiral of silence in Canadian media.
204

Simulações de ondas reentrantes e fibrilação em tecido cardíaco, utilizando um novo modelo matemático / Simulations of re-entrant waves and fibrillation in cardiac tissue using a new mathematical model

André Augusto Spadotto 16 June 2005 (has links)
A fibrilação, atrial ou ventricular, é caracterizada por uma desorganização da atividade elétrica do músculo. O coração, que normalmente contrai-se globalmente, em uníssono e uniforme, durante a fibrilação contrai-se localmente em várias regiões, de modo descoordenado. Para estudar qualitativamente este fenômeno, é aqui proposto um novo modelo matemático, mais simples do que os demais existentes e que, principalmente, admite uma representação singela na forma de circuito elétrico equivalente. O modelo foi desenvolvido empiricamente, após estudo crítico dos modelos conhecidos, e após uma série de sucessivas tentativas, ajustes e correções. O modelo mostra-se eficaz na simulação dos fenômenos, que se traduzem em padrões espaciais e temporais das ondas de excitação normais e patológicas, propagando-se em uma grade de pontos que representa o tecido muscular. O trabalho aqui desenvolvido é a parte básica e essencial de um projeto em andamento no Departamento de Engenharia Elétrica da EESC-USP, que é a elaboração de uma rede elétrica ativa, tal que possa ser estudada utilizando recursos computacionais de simuladores usualmente aplicados em projetos de circuitos integrados / Atrial and ventricular fibrillation are characterized by a disorganized electrical activity of the cardiac muscle. While normal heart contracts uniformly as a whole, during fibrillation several small regions of the muscle contracts locally and uncoordinatedly. The present work introduces a new mathematical model for the qualitative study of fibrillation. The proposed model is simpler than other known models and, more importantly, it leads to a very simple electrical equivalent circuit of the excitable cell membrane. The final form of the model equations was established after a long process of trial runs and modifications. Simulation results using the new model are in accordance with those obtained using other (more complex) models found in the related literature. As usual, simulations are performed on a two-dimensional grid of points (representing a piece of heart tissue) where normal or pathological spatial and temporal wave patterns are produced. As a future work, the proposed model will be used as the building block of a large active electrical network representing the muscle tissue, in an integrated circuit simulator
205

Curved spiral antennas for underwater biological applications

Llamas, Ruben A. 01 July 2015 (has links)
We developed curved spiral antennas for use in underwater (freshwater) communications. Specifically, these antennas will be integrated in so-called mussel backpacks. Backpacks are compact electronics that incorporate sensors and a small radio that operate around 300 MHz. Researchers attach these backpacks in their freshwater mussel related research. The antennas must be small, lightweight, and form-fit the mussel. Additionally, since the mussel orientation is unknown, the antennas must have broad radiation patterns. Further, the electromagnetic environment changes significantly as the mussels burrow into the river bottom. Broadband antennas, such a spiral antennas, will perform better in this instance. While spiral antennas are well established, there has been little work on their performance in freshwater. Additionally, there has been some work on curved spiral antennas, but this work focused on curving in one dimension, namely curving around a cylinder. In this thesis we develop spiral antennas that curve in two dimensions in order to conform the contour of a mussel's shell. Our research has three components, namely (a) an investigation of the relevant theoretical underpinning of spiral antennas, (b) extensive computer simulations using state-of-the art computational electromagnetics (CEM) simulation software, and (c) experimental validation. The experimental validation was performed in a large tank in a laboratory setting. We also validated some designs in a pool (∼300,000 liters of water and ∼410 squared-meter dive pool) with the aid of a certified diver. To use CEM software and perform successful antenna-related experiments require careful attention to many details. The mathematical description of radiation from an antenna, antenna input impedance and so on, is inherently complex. Engineers often make simplifying assumptions such as assuming no reflections, or an isotropic propagation environment, or operation in the antenna far field, and so on. This makes experiments on antennas challenging since it often quite difficult to replicate the simplifying assumptions in an experimental setting. Still, with careful consideration of the important factors and careful experimental design it is possible to perform successful experiments. For example, antenna measurements are often performed in anechoic chambers. For our research we used a large swimming pool to mimic an underwater anechoic chamber. Our CEM simulations and experimental results are in most cases congruent. We are confident that we can design formfitting, compact (spiral) antennas that one could deploy on mussels. This will greatly enhance the mussel backpacks that are used by researchers at the University of Iowa.
206

Multi-Wavelength Statistics of Clumpy Galaxies

Cox, Isaiah, Smith, Beverly J 05 April 2018 (has links)
We calculated the fraction of ‘clumpy’ galaxies (fclumpy) for three samples of nearby galaxies. These samples include interacting galaxies with strong tidal features, collisional ring galaxies, and normal spiral galaxies. We define a ‘clumpy’ galaxy as a galaxy that has luminous star-forming regions contributing more than 8% of the total flux for the galaxy. We calculate fclumpy for 16 different wavelengths. We find that fclumpy is highest in the ultraviolet, Hα, and 24μm, while fclumpy is the lowest in optical and near-infrared wavelengths. We also see a significant increase in fclumpy for the interacting samples compared to the normal spirals.
207

Endovascular trophoblast expresses CD59 to evade complement-dependent cytotoxicity / 血管内トロホブラストはCD59を発現し補体依存性細胞傷害を回避する

Ueda, Masashi 23 September 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22744号 / 医博第4662号 / 新制||医||1046(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 髙折 晃史, 教授 竹内 理, 教授 近藤 玄 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
208

Facilitated Transport Membranes for Fuel Utilization Enhancement for Solid Oxide Fuel Cells and Carbon Capture from Flue Gas

Chen, Kai January 2020 (has links)
No description available.
209

Úprava křižovatky I/50 x III/3836 u Velešovic / Modifying the intersection of I/50 x III/3836 Velešovice

Sýkora, Martin January 2012 (has links)
My thesis is about intersection which is very dangerous, because there is´t lighting so intersection is unclear and drivers don´t to abide speed limit. There are serious accidents so I had to modify it. I designed three versions: First with concrete barriers, second is in trims and last one is spiral roundabout. Last version is more refined. Every version is with LED lighting in all area.
210

Přestavba křižovatky Merhautova – Okružní – Seifertova v Brně / Reconstruction of Merhautova – Okruzni – Seifertova crossing in Brno

Palán, Libor January 2013 (has links)
The theme of this master thesis is a way of solving tram track elongation in Brno - Lesna. The task was to draw up a tram track through the crossroad of streets Merhautova, Seifertova and Okruzni including reconstruction of crossroad. This master thesis deals with the of different variants of solution of crossroad. The most appropriate option is worked out further. In this work is also included outlining of futher tram tracking behind the crossroad and placement of the nearest tram stops. The result of this work is to elaborate of the situation including charasteristic cut sections and longitudinal profiles of tram lines. Part of this work is an estimate of the financial cost to realize this building.

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