京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21577号 / 理博第4484号 / 新制||理||1644(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 千木良 雅弘, 教授 釜井 俊孝, 准教授 松四 雄騎 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

This master’s thesis deals with a design of a telescopic axle and evaluation of the tandem suspension frame mounted on silage wagons Pöttinger Primo and Faro while they are operating a slope. Thesis describes the whole design as well as a hydraulic system and a braking system. This part also consists of maintenance and adjusting instructions. The second part of the thesis is dedicated to a slope capacity calculation based on ISO 16231-2. Strength analysis for all the parts is done, using finite element method for various working modes.

<p>Since the discovery of graphene, two-dimensional (2D) materials have attracted broad interests for transistor applications due to their atomically thin nature. This thesis studies nano-transistors based on 2D materials for several novel applications, including tunneling transistors for low-power electronics and reconfigurable transistors for hardware security.</p><p>The first part of the thesis focuses on tunneling field-effect transistors (TFETs). Since the current injection in a conventional MOSFET depends on thermionic injection over a gate-controlled barrier, the subthreshold swing (SS) of MOSFET is fundamentally limited to 60 mV/dec at room temperature, hindering the supply voltage scaling of integrated circuits (ICs). Utilizing band-to-band tunneling (BTBT) as current injection mechanism, TFETs overcome the SS limit by filtering out the Fermi tail in the source and achieve steep-slope switching. However, existing demonstrations of TFETs are plagued by low on-currents and degraded SS, largely due to the large tunneling distances caused by non-scaled body thicknesses, making 2D materials a promising candidate as channel materials for TFETs. In this thesis, we demonstrate a prototype TFET based on black phosphorus (BP) adopting electrostatic doping that is tuned by multiple top-gates, which allows the device to be reconfigured into multiple operation modes. The band-to-band tunneling mechanism is further confirmed by source-doping-dependent and temperature-dependent measurements, and the performance improvement of BP TFETs with further body and oxide thicknesses scaling is projected by atomistic simulation. In addition, a vertical BP TFET with a large tunneling area is also demonstrated, and negative differential resistance (NDR) is observed in the device.</p><p>The second part of the thesis focuses on reconfigurable nano-transistors with tunable p- and n-type operations and the implementation of hardware security based on such transistors. Polymorphic gate has been proposed as a hardware security primitive to protect the intellectual property of ICs from reverse engineering, and its operation requires transistors that can be reconfigured between p-type and n-type. However, a traditional CMOS transistor relies on substitutional doping, and thus its polarity cannot be altered after the fabrication. By contrast, 2D nano-transistors can attain both electron and hole injections. In this thesis, we review the Schottky-barrier injection in 2D transistors and demonstrate the feasibility of achieving complementary p-type and n-type transistors using BP as channel material by adopting metal contacts with different work functions. In this design, however, the discrepancy in the p-FET and n-FET device structures makes it unsuitable for reconfigurable transistors. Therefore, we continue to modify the device design to enable reconfigurable p-type and n-type operations in the same BP transistor. Finally, a NAND/NOR polymorphic gate is experimentally demonstrated based on the reconfigurable BP transistors, showing the feasibility of using 2D materials to enable hardware security.</p><p>In the last part, we demonstrate an artificial sub-60 mV/dec switching in a metal-insulator-metal-insulator-semiconductor (MIMIS) transistor. Negative capacitance FETs (NC-FETs) have attracted wide interest as promising candidates for steep-slope devices. However, the detailed mechanisms of the observed steep-slope switching are under intense debate. We show that sub-60 mV/dec switching can be observed in a WS2 transistor with an MIMIS structure – without any ferroelectric component. Using a resistor-capacitor (RC) network model, we show that the observed steep-slope switching can be attributed to the internal gate voltage response to the chosen varying gate voltage scan rates. Our results indicate that the measurement-related artefacts can lead to observation of sub-60 mV/dec switching and that experimentalists need to critically assess their measurement setups.</p>

The aim of this work is to study track speed increase in section between Boří les – Hrušovany nad Jevišovkou – line Břeclav – Znojmo. In terms of this work directional and height adjustment is beig suggested. The ambition was to ensure basic accessibility of this area within existing range. The study was prepared and respects costs.

The master’s thesis as focused on the design a kindergarten located in Vrbovec. The project documentation is suited for the execution of construction works. It handles about a single storey object with a green roof and is recessed into the hillside. The green roof corrects seamlessly with the surrounding terrain. A feature of the build is that, it is founded on milled foamglass. Vertical structures are from silicate blocks, excluding the walls in contact with soil are based on hidden formwork. Design of the building respects the local plan of Vrbovec. There are going to be two groups of children, thus the disposition is accustomed to that. Maximum capacity is 48 children. It is shape and color design represents an architectural site, it is properties function in terms of energy savings.

[pt] A preocupação com a preservação ambiental e a sustentabilidade, cada vez mais presente em todos os aspectos da vida do mundo atual, conduz, mais e mais, à busca por fontes de energia limpa, renovável e minimamente agressivas ao meio ambiente. Dentro desse quadro, as usinas hidrelétricas reversíveis - UHRs - retornam mais uma vez como alternativa para matrizes de energia ao produzir energia incomparavelmente mais limpa e racional do que fontes tais como termoelétricas, muito utilizadas na regulação dos picos de consumo de energia. Entretanto, por sua operação peculiar, com ciclos curtos e frequentes de enchimento e rebaixamento do nível de água de seus lagos, o projeto para reservatórios das UHRs não está perfeitamente contemplado nos procedimentos normativos brasileiros usuais para o projeto de usinas hidrelétricas, carecendo de orientações adequadas para o tratamento das margens desses lagos, cuja instabilidade pode levar a problemas econômicos e ambientais bastante inconvenientes. Atento a este problema, este trabalho apresenta um resumo das principais metodologias de análise de estabilidade de taludes sujei-tos a rebaixamento rápido e identifica as potencialidades e limitações dos métodos de equilíbrio limite e numéricos usualmente utilizados, especialmente para o caso das UHRs. Foram apresentadas soluções de tratamento de taludes das margens de reservatórios para usinas reversíveis. O caso das rupturas às margens do reservatório da usina hidrelétrica de Santa Branca é apresentado para ilustrar a gravidade do problema e contribuiu para identificar as limitações para que os referidos métodos sejam efetivamente aplicados. A conclusão do trabalho é que estudos de viabilidade e de projeto de usinas hidrelétricas devem ser aprimorados para incluir as metodologias de estudo de estabilidade na condição de rebaixamento rápido mais atuais, especialmente para taludes marginais, cuja estabilidade condiciona a operação das UHRs, antevendo a possível introdução desta solução na matriz energética brasileira. Por fim, o presente trabalho apresenta recomendações para o aprimoramento dos estudos de viabilidade para a implantação de usinas hidrelétricas reversíveis, considerando o conteúdo dos manuais brasileiros. / [en] Concern about environmental preservation and sustainability, which is increa-singly present in all aspects of life currently, leads to the growth of a search for sources of energy that are clean, renewable and minimally aggressive for the environment. Within this framework, pumped storage power plants - PSPP - return once again as an alternative to energy matrices by producing incomparably cleaner and more rational energy than sources such as thermoelectric, widely used in the regulation of energy consumption peaks. However, due to its peculiar operation, with short and frequent cycles of filling and lowering of the water level of its lakes, the designs of PSPP reservoirs are not entirely covered by the usual Brazilian guidelines for design of hydroelectric plants, lacking appropriate guidance for the treatment of the margins from such reservoirs, whose destabilization can lead to very inconvenient economic and environmental issues. Regardful of this problem, this study presents a summary of the main methods of analysis of stability of slopes subjected to rapid drawdown and identifies the potentialities and limitations of the limit equilibrium methods and numerical methods usually used, especially for the case of PSPP. Slope stabilizations solutions for reservoir banks subjected to rapid drawdowns were presented. The case of the ruptures along the Santa Branca hydroelectric power plant reservoir is presented to illustrate the severity of the problem and has helped to identify the limitations for the effective application of these methods. The conclusion of this study is that feasibility studies and hydropower plant design should be improved in order to include more up-to-date methods of analysis of slope stability under rapid drawdown condition, especially for marginal slopes, which stability conditions the operation of PSPPs, foreseeing the possible introduction of this solution in the Brazilian energy matrix. Finally, this work presents recommendations for the improvement of feasibility studies for the implementation of PSPPs, considering the content of Brazilian guidelines.

Orientador: Cenira Maria Lupinacci / Resumo: Com o auxílio de diversos ramos da ciência, o ser humano buscou o desenvolvimento de suas demandas ao longo da história junto ao espaço natural, chegando para alguns autores, do ponto de vista do relevo, a ser denominado como um novo agente geomorfológico. A partir disso, as ações humanas vêm modificando o relevo em ambientes rurais, tanto para fins de agricultura como de pecuária. A fim de colaborar com os estudos que visam compreender os mecanismos de desenvolvimento de feições erosivas lineares e sua interação com agentes antropomórficos, teve-se como objetivo desta pesquisa apontar o potencial ao avanço erosivo linear de feições localizadas em uma bacia hidrográfica alocada no setor cuestiforme de Analândia (SP). Para o desenvolvimento da pesquisa, utilizaram-se as orientações de Mathias (2016), realizando o levantamento de diversas variáveis (granulometria, infiltração, resistência do solo à penetração, permeabilidade, declividade, fluxo acumulado de superfície e uso da terra) para formulação de cartas de síntese, as quais foram validadas a partir das áreas de ocorrência de feições erosivas e a partir dos dados de evolução do talude de uma voçoroca. Para validação, pautou-se na hipótese de que as classes com alto potencial ao avanço erosivo deveriam ter uma boa correspondência com os setores de maior concentração de feições erosivas e maior evolução do talude. Assim, tal sistemática permitiu identificar o setor central da bacia como uma zona de concentração de feições er... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: With help of several Science fields, human beings sought to develop their demands throughout history all over the natural space, reaching out to some authors, from the point of view of relief, to be named as a new geomorphological agent. From this, human actions have been modifying the relief in rural environments, for agriculture and livestock purposes. Seeking to collaborate with studies that aim to understand the mechanisms of development of linear erosive features and their interaction with anthropomorphic agents, this research goal was to indicate the potential to linear erosive rise of features located in a watershed located in the cuestiform sector from Analândia (SP). For the research development, it has been used the guidelines of Mathias (2016), performing the survey of several variables (particle size, infiltration, penetration resistance, permeability, slope, accumulated surface flow and land use) for the formulation of maps synthesis, which were validated from the areas of erosive features and from the evolution data of a gully erosion. For validation, it was based on the hypothesis that the kinds with high potential to erosive rise should have a good correspondence with sectors in higher concentration of erosive features and larger slope evolution. Thus, this systematic allowed to identify the central sector of the watershed as a zone of concentration of linear erosive features, which constitutes a transition area between the more resistant clay soils (to the no... (Complete abstract click electronic access below) / Mestre

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Measuring the research performance of a university is important to the universities themselves, governments, and students alike. Among other metrics, the number of publications is easy to obtain, and due to the large number of publications each university produces during one year, it suggests to be one accurate metric. However, the number of publications depends largely on the size of the institution, suggesting, if not addressed, that larger universities are better. Thus, one might intuitively try to normalize by size and use publications per researcher instead. A better institution would allow individual researchers to have more publications each year. However, publications, like many other things, might follow a power-law distribution, where most researchers have few, and only a few researchers have very many publications. These power-law distributions violate the assumptions the central limit the orem makes, for example, having a well-defined mean or variance. Specifically, one can not normalize or use averages from power-law distributed data, making the comparison of university publications impossible if they indeed follow a power-law distribution. While it has been shown that some scientific domains or universities show this power-law distribution, it is not known if Swedish universities also show this phenomenon. Thus, here we collect publication data for Swedish universities and determine whether or not, they are power-law distributed. Interestingly, if they are, one might use the slope of the power-law distribution as a proxy to determine research output. If the slope is steep, it suggests that the ratio between highly published authors and those with few publications is small. Where as a flatter slope suggests that a university has more highly published authors than a university with a steeper slope. Thus, the second objective here is to assess if the slope of the distribution can be determined or to which extent this is possible. This study will show that eight of the fifteen Swedish universities considered follow a power-law distribution (Kolmogorov-Smirnov statistic&lt;0.05), while the remaining seven do not. The key determinant is the total number of publications. The difficulty here is that often the total number of publications is so small that one can not reject a power-law distribution, and it is also impossible to determine the slope of the distribution with any accuracy in those cases. While this study suggests that in principle, the slopes of the power-law distributions can be used as a comparative metric, it also showed that for half of Sweden’s universities, the data is insufficient for this type of analysis.

The objective of this research was to determine the environmental and social factors that led to the shift of settlement patterning from agro-pastoral in the late Neolithic to hillort sites at the turn of the Early Bronze Age and why burial mounds (tumuli) were erected further than anticipated from corresponding hillort sites in the Shkodra Plain region in Northern Albania. Geospatial techniques were used to examine 168 tumuli and seven hillort sites. These were mapped to examine visibility, viewshed, slope, and potential prehistoric networks. Based on the landscape visibility GIS results, it was found that hillort sites and tumuli were part of an social landscape that thrived on trade. It was determinable that the shift of the social landscape was related to Northern trade routes and probable changes in paleo-lake levels. This new evidence provides insight to Albanian prehistoric culture and has implications to related studies in the Balkans.