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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.
341

Rekonstrukce zdraví a životního stylu jedinců pohřbených v sídlištních jamách a hrobech starší a střední doby bronzové na základě patologických znaků na kostře / Health reconstruction of individuals buried in settlements and graves in Early Bronze Age based on pathological traces on skeletons

Pankowská, Anna January 2014 (has links)
An increase in the diversity of Early Bronze Age (EBA) burial practices is well documented in central and southern Moravia between 2200-1500 BC. Apart from scarce cremations and pithoi burials, two more frequent parallel burial types appear. One is the standard burials in cemeteries, the other burials in settlement pits, the latter considered a deviation until recently. Thanks to recent excavations and new quantification procedures, however, abundance of settlement burials as well as uniformity and predictability of body deposition and grave equipment in pit burials has been shown. My intention is to show the existence of two parallel burial rites on the basis of bioarchaeological and archaeological evidence. I focus on the reconstruction of health and social status of individuals buried in settlement pits and graves. I observe the amount of demographic variability, diseases and trauma within each group. I suppose the distribution of diseases according to age, sex and archaeological record will be similar within each of the groups. As a result, we may speak about two equivalent burial practices. If deviations are encountered within settlement pits, however, we should speak about deviations or burials determined for a minority and homogeneous segment of population. Skeletons originate in two...
342

Considerações sobre dissipação de energia a jusante de vertedouros salto esqui / Aspects to consider about energy dissipation downstream of a ski-jump spillyay

Borja, João Gerdau de January 2012 (has links)
Em aproveitamentos hídricos, onde podem estar envolvidas elevadas alturas de água armazenada, o vertedouro é a estrutura hidráulica responsável por conduzir com segurança o escoamento que excede a capacidade de armazenamento do reservatório. Neste aspecto, é necessário considerar o processo de dissipação de energia a fim de proteger o pé da barragem e a própria estrutura do vertedouro contra a ação erosiva da água. Este fluxo que é descarregado é usualmente amortecido por um colchão d’água, o qual é delimitado em uma bacia de dissipação projetada com intuito de resistir aos esforços impostos pelo escoamento. Em grandes barramentos, a utilização de um vertedouro tipo salto esqui, que é caracterizado por um defletor de fluxo no final de sua calha, possibilita que não haja necessidade de revestir o leito próximo do pé da barragem, pois a incidência do jato lançado ocorre distante deste local. Desta maneira, a dissipação da energia é efetuada sobre o próprio leito do rio, sendo formada uma fossa de erosão, contudo, dependendo da resistência do leito e de suas características anisotrópicas, os padrões de recirculação do fluxo podem fazer a fossa evoluir para uma situação nociva. Por isso, desde a fase de projeto desse tipo de vertedouro, monitoramento e previsões da progressão da fossa são essenciais. Então, conforme proposta deste trabalho, abordou-se cada fenômeno que influencia no potencial erosivo do jato, como a turbulência em sua emissão e o grau de difusão do mesmo no colchão d’água. Assim, com ensaios sobre modelo físico, foi possível desenvolver duas metodologias, aplicáveis tanto para a verificação da erosão de material granular na superfície de leitos, quanto para o interior de leitos rochosos fissurados, cujas forças atuantes em um bloco de rocha isolado, podem vencer seu peso submerso e o destacar da matriz. / In hydroelectric plants, which may be involved elevated heights of stored water, the dam spillway is responsible for safely flow the water that exceeds the storage capacity of the reservoir. In this respect, it is necessary to consider the process of energy dissipation in order to protect the base of the dam and the spillway structure itself against the erosive action of the water. This stream discharged is usually cushioned by a waterbed, which is bounded into a stilling basin designed with the purpose of resist the efforts imposed by the flow. In large dams, the use of a ski jump spillway type, which is characterized by a flow deflector at the end of its chute, allows no need lining the bed near the foot of the dam, since the impact of the jet is launched away this location. Thus, the energy dissipation is performed on the riverbed itself, generating a scour hole, however, depending on the resistance of the bed and its anisotropic features, patterns of flow recirculation can evolve the pit into a harmful state. For this reason, since the design phase of this type of spillway, monitoring and predicting the progression of the pit are essential. Then, according to the proposal of this work, it was dealt with each phenomenon that influences the erosive potential of the jet, as the turbulence at its issue on the air, and the level of its diffusion of on waterbed. Based on physical model tests, it was possible to develop two methodologies, applicable both for verifying erosion of granular material from the surface of the bottom, as for analyze the interior of a fissured bedrock, which the forces acting on an isolated block of rock can overcome its submerged weight and uplift it off the matrix.
343

Desenvolvimento de uma sistemática de melhoria do desempenho econômico de indústrias extrativas : o caso de uma mineração a céu aberto / Development of a systematic of economic performance improvement of Extractive Industries – the case of an open-pit mining

Schäfer, Fábio January 2012 (has links)
Em função da globalização, os ambientes empresariais estão se tornando mais competitivos; assim, aumenta a preocupação e a necessidade de se prover um sistema de informações gerenciais que seja eficaz, confiável e relevante para auxiliar os gestores a tomarem decisões inteligentes. Com a utilização de princípios e métodos de custeio vinculados aos serviços inerentes aos métodos e operações de lavra, este trabalho tem como primeiro objetivo identificar e compreender as deficiências dos atuais sistemas de custeio e de produção e estruturar uma sistemática que apoie a avaliação do desempenho econômico-financeiro nas minerações a céu aberto. O segundo objetivo deste trabalho é utilizar o método do custo-padrão vinculado à produção e às regras de negócio e validá-lo mediante a comparação do realizado versus previsto nas minerações a céu aberto, através da utilização de conceitos de desperdícios, do princípio do custeio por absorção parcial, do controle e gestão de custos e de produção para avaliação de resultados. A unidade de extração mineral estudada utiliza o método de lavra por bancadas em cava e terceiriza as operações de descobertura, perfuração, detonação, escavação, carregamento e transporte. A empresa contratada utiliza o princípio de custeio por absorção total e o método de custeio de centros de custos. Assim, a sistemática que apoia a avaliação do desempenho econômico-financeiro juntamente com o método do custo-padrão foi validada e desenvolvida em três serviços terceirizados com o objetivo de verificar a sua funcionalidade e a sua praticidade. Portanto, as novas informações gerenciais auxiliam o gestor identificar a produtividade e a lucratividade do empreendimento e os resultados dos serviços e de suas operações, além de todos os custos gerenciais já existentes. / In the light of globalization, the enterprise environments are becoming more competitive; thus, increases the concern and the need to provide a management information system that is effective, reliable and relevant to assist managers to make intelligent decisions. With the use of principles and costing methods linked to services inherent in mining operations and methods, this work is intended mainly identify and understand the weaknesses of the current costing and production system and structure a systematic that supports performance evaluation productive-economic-financial in surface mining. The second objective of this work is to use standard cost method linked to production and business rules and validate it by comparing the accomplished against foreseen in surface mining, through the use of concepts of wastes, the principle costing of partial absorption, cost control and management for production to evaluation of results. The mineral extraction unit studied uses the open pit mining method and outsources the mining operations of pre stripping, drilling, blasting, rock excavation, loading and transportation. The outsourced company uses the costing principle of total absorption and the costing method is the cost centers. Thus, the systematic that support the evaluation of productive-economic-financial performance and the standard cost method were developed and validated in three outsourced services with the goal of verifying its functionality and practicality. Therefore, the new management information assists the manager to identify the productivity and profitability of the enterprise and the results of its operations and services, in addition to all of the existing management costs.
344

Considerações sobre dissipação de energia a jusante de vertedouros salto esqui / Aspects to consider about energy dissipation downstream of a ski-jump spillyay

Borja, João Gerdau de January 2012 (has links)
Em aproveitamentos hídricos, onde podem estar envolvidas elevadas alturas de água armazenada, o vertedouro é a estrutura hidráulica responsável por conduzir com segurança o escoamento que excede a capacidade de armazenamento do reservatório. Neste aspecto, é necessário considerar o processo de dissipação de energia a fim de proteger o pé da barragem e a própria estrutura do vertedouro contra a ação erosiva da água. Este fluxo que é descarregado é usualmente amortecido por um colchão d’água, o qual é delimitado em uma bacia de dissipação projetada com intuito de resistir aos esforços impostos pelo escoamento. Em grandes barramentos, a utilização de um vertedouro tipo salto esqui, que é caracterizado por um defletor de fluxo no final de sua calha, possibilita que não haja necessidade de revestir o leito próximo do pé da barragem, pois a incidência do jato lançado ocorre distante deste local. Desta maneira, a dissipação da energia é efetuada sobre o próprio leito do rio, sendo formada uma fossa de erosão, contudo, dependendo da resistência do leito e de suas características anisotrópicas, os padrões de recirculação do fluxo podem fazer a fossa evoluir para uma situação nociva. Por isso, desde a fase de projeto desse tipo de vertedouro, monitoramento e previsões da progressão da fossa são essenciais. Então, conforme proposta deste trabalho, abordou-se cada fenômeno que influencia no potencial erosivo do jato, como a turbulência em sua emissão e o grau de difusão do mesmo no colchão d’água. Assim, com ensaios sobre modelo físico, foi possível desenvolver duas metodologias, aplicáveis tanto para a verificação da erosão de material granular na superfície de leitos, quanto para o interior de leitos rochosos fissurados, cujas forças atuantes em um bloco de rocha isolado, podem vencer seu peso submerso e o destacar da matriz. / In hydroelectric plants, which may be involved elevated heights of stored water, the dam spillway is responsible for safely flow the water that exceeds the storage capacity of the reservoir. In this respect, it is necessary to consider the process of energy dissipation in order to protect the base of the dam and the spillway structure itself against the erosive action of the water. This stream discharged is usually cushioned by a waterbed, which is bounded into a stilling basin designed with the purpose of resist the efforts imposed by the flow. In large dams, the use of a ski jump spillway type, which is characterized by a flow deflector at the end of its chute, allows no need lining the bed near the foot of the dam, since the impact of the jet is launched away this location. Thus, the energy dissipation is performed on the riverbed itself, generating a scour hole, however, depending on the resistance of the bed and its anisotropic features, patterns of flow recirculation can evolve the pit into a harmful state. For this reason, since the design phase of this type of spillway, monitoring and predicting the progression of the pit are essential. Then, according to the proposal of this work, it was dealt with each phenomenon that influences the erosive potential of the jet, as the turbulence at its issue on the air, and the level of its diffusion of on waterbed. Based on physical model tests, it was possible to develop two methodologies, applicable both for verifying erosion of granular material from the surface of the bottom, as for analyze the interior of a fissured bedrock, which the forces acting on an isolated block of rock can overcome its submerged weight and uplift it off the matrix.
345

Influence des incertitudes géométriques et de la méthode de modélisation dans l'analyse de stabilité des talus rocheux : application aux mines à ciel ouvert / Influence of geometrical uncertainties and modeling method on stability analysis of fractured rock masses : application to open-pit mines

Nguyen, Anh Tuan 11 December 2015 (has links)
La stabilité des exploitations à ciel ouvert (mines ou carrières) excavées dans des massifs rocheux dépend de leur géométrie, des caractéristiques géométriques de la fracturation (orientation et espacement) du massif et des caractéristiques mécaniques du massif et des discontinuités. L'évaluation du risque d'instabilité rocheuse dépend de la quantité et la qualité des informations disponibles sur le massif rocheux et des méthodes d'analyse mises en œuvre pour évaluer le comportement mécanique de l'assemblage de blocs rocheux. Différents sites de talus naturels, d'excavation routière et de carrières et mines à ciel ouvert présentés dans le mémoire montrent que les informations connues peuvent beaucoup varier d'un site à l'autre. Les étapes de collecte et de synthèse des données, puis de modélisation afin d'analyser la stabilité d'une pente rocheuse conduisent à des incertitudes. Le mémoire traite plus particulièrement de l'influence des incertitudes géométriques et différentes méthodes de regroupement des fractures en familles sont explorées. La combinaison du travail proposé par différents auteurs conduit à une nouvelle méthode nommée PSMY. Cette méthode ainsi que la méthode spectrale ont été programmées sous l'environnement Mathematica et les résultats sont comparés à des regroupements "manuels" réalisé avec le logiciel DIPS. Les méthodes de regroupement sont présentées selon le pourcentage d'orientations classé par la méthode. L’orientation et l’espacement des familles de fractures sont ajustées à des lois statistiques. Les paramètres statistiques sont comparés en fonction de la méthode regroupement. Ces paramètres influencent la construction d'un modèle géométrique du massif rocheux appelé DFN (Discrete Fracture Network). L'influence des regroupements sur l'analyse de stabilité est étudiée à partir de modélisation stochastiques à l'équilibre limite utilisant les logiciels SWEDGE et RESOBLOK. Ces logiciels ne prennent pas en compte les mêmes incertitudes et en sortie ils fournissent des indicateurs de stabilité différents. Une analyse de sensibilité des indicateurs (nombre de blocs instables, volume moyen du bloc instable, volume total instable) aux méthodes de regroupement et aux orientations de talus est réalisée. Une analyse de variance permet de préciser l'influence de ces deux facteurs. Une évaluation de l’état de stabilité global du massif, en fonction de la cohésion et de l'angle de frottement est proposée. L'influence de la méthode de modélisation est évoquée en comparant des calculs tridimensionnels à l'équilibre limite et des modélisations bidimensionnel et tridimensionnels en éléments discrets rigides ou déformables. Un couplage entre le logiciel RESOBLOK (équilibre limite) et LMGC90 (éléments discrets) permet de comparer les analyses pour une même géométrie. Pour le cas de la déviation d'Ax-les-Thermes et certaines configurations géométriques instables l’influence des paramètres de modèles sur stabilité du talus est testée. Plusieurs variantes sont comparées. La simulation d’une excavation en 3D multi phases est réalisée et l’indice de mobilisation est étudié pour comparer les divers types de contacts dans LMGC90 par rapport à l’éventuel glissement des blocs dans les étapes successives / The stability of open-cast operations (mines or quarries), excavated in rock mass depends on their geometry, the geometrical characteristics of the rock mass fractures (orientation and spacing) and the mechanical characteristics of the rock mass and the discontinuities. The assessment of the rock instability risk depends on the quantity and quality of the available information on the rock mass and the analysis methods used for the evaluation of the mechanical behavior of the rock block collection. Different sites of natural rock slopes, of road cuts, and of open-cast mines and quarries, described in the present document, show that the known information can vary a lot from one site to the other. The steps of data gathering and analysis, then the modelling step used to analyze the stability of the rock slope, lead to uncertainties. The present work deals in particular with the influence of the geometrical uncertainties, and the different clustering methods, to define families of fractures, are examined. The combination of works suggested by several authors leads to a new method called PSMY. This method, together with the spectral method, was coded in the Mathematica platform, and the obtained results are compared with "hand-made" clusters, done with the DIPS software. The clustering methods are presented according to the ratio of classified orientations. The orientation and spacing of fracture families are fitted by statistical law. The statistical parameters are compared according to the clustering method used. These parameters have an influence on the construction of the rock mass geometrical model, called DFN (Discrete Fracture Network). The influence of the clusters on the stability analysis is studied from the stochastic models based on the limit equilibrium analysis, in the SWEDGE and RESOBLOK software. These programs do not take into account the same uncertainties, and as a result, they give different stability indicators. A sensitivity analysis of these indicators (number of unstable blocks, average volume of unstable blocks, and total volume of unstable blocks) versus the clustering methods used, and the orientation of the slopes, is carried out. A variance analysis allows an evaluation of the influence of these factors. The assessment of the global stability condition of the rock mass, depending on the cohesion and the friction angle, is proposed. The influence of the modeling method is analyzed by comparing 3D calculations using the limit equilibrium calculations, and 2D and 3D models using discrete rigid and deformable blocks. A coupling between RESOBLOK (limit equilibrium) and LMGC90 (discrete elements) allows the comparison of results on the same original geometry. For the case of Ax-les-Thermes road-cut, and for various unstable geometries, the influence of the model parameters is tested. Several cases are compared. The 3D simulation of an excavation, at different steps, is performed, and the mobilization index is studied, in order to compare several types of contacts, within the LMGC model, in relation to the possible sliding of blocks, at those different steps
346

Inventering av kärlväxter i Vapnö grustäkt

Sjövall, Anna January 2017 (has links)
Höga kvävenedfall och förändringar inom jord- och skogsbruk har lett till igenväxning av svenska sandmarker. Sand- och grustäkter kan fungera som tillflyktsort för kärlväxtarter som är beroende av de torra och näringsfattiga markförhållanden som finns i sandmarker. Vapnö grustäkt i Hallands län undersöktes 2010 och visade sig ha en hög biologisk mångfald med bland annat 145 kärlväxtarter, varav fyra rödlistade. Syftet med den här studien var att se hur artsammansättningen av kärlväxter ser ut idag, sju år senare. Området inventerades vid tio tillfällen från april till augusti och samtliga kärlväxtarter noterades. Resultatet blev en lista på 224 arter varav 63 var återfynd från 2010 och 161 var nya arter för området. Det fanns fem rödlistade arter: Knippnejlika (Dianthus armeria) (EN), hårginst (Genista pilosa) (NT), backtimjan (Thymus serpyllum) (NT), skogsalm (Ulmus glabra) (CR) och naverlönn (Acer campestre) (CR). Det totala antalet arter och rödlistade arter har ökat sen 2010, vilket tyder på en positiv utveckling av områdets biologiska mångfald. Den höga artmångfalden beror troligen på det öppna, varierande landskapet och de rödlistade arterna växer där tack vare den alltmer ovanliga sandmarken. Områdets mångfald av kärlväxter hotas av igenväxning samt konkurrens från de invasiva arterna blomsterlupin (Lupinus polyphyllus) och parkslide (Fallopia japonica). Detta kan motverkas av störningar i form av slåtter, uppgrävning, naturvårdsbränning eller bete. / Nitrogen deposition and changes in agriculture and forestry have led to a decrease of sandy habitats in Sweden due to regrowth of vegetation. Sand- and gravelpits can act as refuges for vascular plants that require the dry and nutrient-poor conditions of sandy soils. Vapnö gravelpit in Halland county in Sweden was surveyed in 2010 and proved to hold a high biodiversity including 145 species of vascular plants, of which four were red-listed. Now, seven years later, the purpose of this study was to see how the composition of vascular plants has changed since then. The area was studied on ten occasions from April to August, and all species of vascular plants were noted. The study resulted in a list of 224 species, of which 63 were remaining since 2010 and 161 were new species for the area. There were five red-listed species: Dianthus armeria (EN), Genista pilosa (NT), Thymus serpyllum (NT), Ulmus glabra (CR) and Acer campestre (CR). The total number of species and red-listed species have increased, suggesting a positive development of the biodiversity of the area. The high species diversity is probably due to the open, varied landscape and the presence of the red-listed species due to the increasingly rare sandy habitat. The diversity of vascular plants in the area is threatened by regrowth of vegetation, as well as the invasive species Lupinus polyphyllus and Fallopia japonica. These threats can be counteracted by disturbance in the form of mowing or digging up plants, prescribed burning or grazing.
347

Experimental and modelling studies of corrosion fatigue damage in a linepipe steel

Fatoba, Olusegun Oludare January 2016 (has links)
The work is concerned with the development of a multi-stage corrosion fatigue lifetime model, with emphasis on pitting as a precursor to cracking. The model is based upon the quantitative evaluation of damage during the overall corrosion fatigue process. The fatigue response of as-received API 5L X65 linepipe steel has been investigated in terms of the evolution of damage during pit development, pit-to-crack transition and crack propagation. Micro-potentiostatic polarisation was conducted to evaluate role of stress on pit development. Crack growth rate measurements were conducted on pre-pitted specimens, which were tested in air and brine, to evaluate the initiation and propagation behaviour of cracks emanating from artificial pits. Finite element analysis was undertaken to evaluate the stress and strain distribution associated with the pits. A cellular automata finite element model was also developed for predicting corrosion fatigue damage. Pit growth rate was enhanced under stress. It was considered that the strain localisation effect of the pit facilitated strain-assisted dissolution. In air, cracks initiated predominantly from the pit mouth. FEA results indicated that this was due to localisation of strain towards the pit mouth. In corrosion fatigue, cracks tended to initiate at the pit base at low stress and at the pit mouth at higher stresses. Crack initiation lifetimes were shorter in the aggressive environment compared to air and the effect of the environment on crack initiation lifetime was lower at higher stress levels. Crack initiation lifetime for double pits generally decreased with decreasing pit-to-pit separation distance. The microstructure was observed to influence crack growth behaviour in air particularly in the early stages when cracks were short. The acceleration and retardation in crack growth were attributed to the resistance of grain boundaries to crack advance. Cracks sometimes arrested at these barriers and became non-propagating. Introduction of the environment for a short period appear to eliminate the resistance of the microstructural barriers thus promoting re-propagation of the previously arrested crack. The continued crack propagation after the removal of the environment suggests that the influence of the environment is more important in the early stages of crack growth. Crack growth rates were higher in the aggressive environment than in air. The degree of environmental enhancement of crack growth was found to be greater at lower stress levels and at short crack lengths. Oxide-induced crack closure and crack coalescence were two mechanisms that also affected crack growth behaviour.2-D cellular automata finite element simulation results, with and without stress, show good agreement agreed with experiments i.e. pit depth and pit aspect ratio increase with time. Results from 3-D cellular automata simulations of pits are also consistent with experiments. Fatigue lifetimes were significantly shorter (i) in the brine environment than in air and (ii) for specimens with double pits compared to single pits of similar depth. Fatigue strength in air was found to decrease with increasing pit depth. Corrosion fatigue lifetimes predicted based upon the developed model showed good agreement with the experimental lifetimes.
348

Založení polyfunkčního domu v Olomouci / The Design of Multifunctional Building Foundations in Olomouc

Dubčák, Pavel January 2012 (has links)
The topic of my master`s thesis is to design foundations of multifunctional building in Olomouc. Another part of this master`s thesis deals with safe and economic design solution of shoring wall. This construction is used to built underground parts of the building. The last part of the work contains description of technological proces of the geotechnics constructions execution. The drawing documentation is also included.
349

Založení mostu / Foundation of Bridge

Ščudla, Martin January 2014 (has links)
The thesis focuses on design of 5 - square bridge foundation in Ostrava Svinov including covering of construction pits. The bridge is founded on the groups of drilled large diameter piles. Design and assessment is realized in program GEO 5. The thesis is divided into 6 parts: introduction, geotechnical circumstances, concomitant report, static calculations, technical report and documentation.
350

Stavební jámy kruhového průřezu / Foundation Pits of Circular Cross-section

Plevová, Lenka January 2014 (has links)
The master´s thesis focuses on design of underground sprinkler tank for a shopping centre Sconto in Hradec Králové. The purpose of this thesis is to design and to analyse all parts of this construction. These parts are the roof, the bottom plate and the wall, which is represented by secant piles. Due to the high level of the ground water which causes a great pressure on the bottom of the tank, the solution of the bottom plate represents very important part of this thesis. There were used two programs for an analysis, Scia Engineer 2013 and FIN EC – Beton 3D. Furthermore, the work contains a view and a brief description of methods used for sheeting of foundation pits of a circular cross-section. In the end, this thesis contains the design of two other solutions of bottom plate and its economic comparison.

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