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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.
161

Arkeologers användning av utgrävningsdokumentation : en studie av användningen av forskningsdokumentation från Labraunda / Archaeologists’ use of excavation documentation : a study of the use of research documentation from Labraunda

Pettersson, My January 2018 (has links)
This essay deals with the use of archival excavations documents among archeologists, with the focus on the Swedish excavation in Labraunda, Turkey. The purpose with this study was to facili- tate the work at archival institutions with excavation documents, and to create more knowledge about the use of archival excavation documents. This study can also help the archival institutions to preserve and mediate this type of documentation. In addition, this study also adds more knowledge about what type of archival documentation the users prefer to use. Method that have been used are interviews, which six persons that have or are working with documentation from Labraunda. In addition with, document studies are used as a complement, where publications, based on archival document from Labraunda, written by the interviewed individuals have been studied. Con- cluding of this study is that the archeologists using archived excavation documentation needs to process the documents before any contemporary analysis can be made. Moreover, it seems that it is a patchwork between using their own and others documentation, to fill in the information gaps or find similarities. Furthermore, some of the most used document types is, according to this study, photographs and drawings of ceramics.
162

Classificação de maciços rochosos: uma abordagem por redes neurais / Rock mass classification: a neural network approach

Paulo Gustavo Cavalcante Lins 24 April 2002 (has links)
Os sistemas de classificação maciços rochosos e as redes neurais artificiais possuem diversas similaridades. Existem características que estão presentes nos dois tipos de sistemas: bases de dados são usadas para o seu desenvolvimento; e pesos são parte da representação do conhecimento. Os principais sistemas de classificação geomecânicas (Sistema Q e RMR) podem ser escritos como representações neurais locais. Tais representações permitem uma melhor compreensão do processo de classificação e identificação de padrões realizado pelas classificações convencionais. Experimentos convencionais foram realizados com modelos de redes neurais não-supervisionados. Os modelos não supervisionados permitiriam uma melhor compreensão da distribuição dos dados no espaço de feições. Um modelo supervisionado para escavações subterrâneas em todo domínio do espaço de feições. Importantes relações entre características foram encontradas. / Rock mass classification systems and artificial neural networks have several similarities. There is some characteristics present in both systems: data bases are used in they development, and weights are part of the knowledge representation. The main rock mass classification systems (Q-system and RMR) can be written as local neural network representations. This representation helps a better understanding of the pattern classification and identification process made by the conventional classifications. Computational experiments were made with unsupervised and supervised neural networks models. Unsupervised models allow a better understanding of the data in the feature space. A supervised model allow to make a mapping of the support type used in underground excavation in all feature space domain. Important relations between domain regions characteristics and type of support used were found.
163

Aldeias e organização espacial dos povos produtores da cerâmica Aristé: contribuições para a Arqueologia das unidades habitacionais da costa atlântica do Amapá / Villages and spatial organisation of the producer peoples of Aristé pottery: Contributions to the Household Archaeology of the Atlantic coast of Amapá.

Michel Bueno Flores da Silva 03 August 2016 (has links)
Apesar de conhecidas arqueologicamente desde o século XIX e historicamente desde o início da conquista europeia, as cerâmicas filiadas à fase Aristé sempre tiveram maior repercussão quando provindas de contextos cerimoniais, devido à elaborada composição decorativa de seus materiais, bem como, o aspecto monumental e cerimonial destes sítios. As cerâmicas desta fase foram divididas em dois períodos cronológicos distintos: Ouanary Encoché e Enfer Polychrome, com profundidade cronológica de mais de um milênio, contudo esta divisão é baseada, principalmente, nos vestígios oriundos destes contextos especializados. Portanto, através desse trabalho busca-se verificar se esta divisão se mantém nos contextos domésticos e, uma vez verificada esta carência de dados empíricos oriundos destes contextos, procurar-se-á, com base nos resultados de escavações mecânicas, contribuir para uma arqueologia das unidades habitacionais filiadas à fase Aristé, através da correlação dos dados cerâmicos com os dados espaciais. Com esse fim, foram elaboradas as tipologias das cerâmicas e das estruturas antrópicas identificadas durante a escavação, permitindo sua interpretação através da análise espacial dos resultados, por fim, possibilitando a inferência de áreas de atividade e melhor compreensão desta fase arqueológica da costa atlântica do Amapá. / Although known archaeologically since the nineteenth century and historically since the European conquest, ceramics affiliated to Aristé phase always had greater impact when stemmed from ceremonial contexts, due to the elaborate decorative composition of their materials, as well as the monumental and ceremonial aspects of these sites. The ceramics of this phase were divided into two distinct chronological periods: Ouanary Encoché and Enfer Polychrome with chronological depth of more than a millennium, but this division is based mainly on traces originating from these specialized contexts. Therefore, this work seeks to verify if this division is maintained in domestic contexts and, once verified the lack of empirical data from these contexts, will be sought, based on the results of mechanical excavation, contribute to a household archeology of the Aristé phase by correlating ceramic data with spatial data. For this purpose were developed typologies of ceramics and anthropogenic structures identified during the excavation, allowing its interpretation through the spatial analysis of the results, at last, providing inferences of activities areas and a better understanding of this archaeological phase of the Atlantic coast of Amapá.
164

Proposição de critérios técnicos e ambientais para criação de banco de solos para a região metropolitana de São Paulo. / Proposition of technical and environmental criteria for the creation of a soil bank for the metropolitan of São Paulo.

Karen Kataguiri 21 March 2017 (has links)
Considerando a necessidade de soluções sustentáveis para a destinação de solos de escavação de obras em áreas urbanas, este estudo apresenta a caracterização de materiais de escavação recebidos em um aterro de resíduos de construção civil (RCC) localizado na Região Metropolitana de São Paulo (MRSP). As amostras foram classificadas visualmente como predominantemente solo de escavação ou mistura de diferentes tipos de RCC, e submetidas a testes de caracterização química, mineralógica, ambiental e geotécnica. Os materiais de escavação destinados ao aterro são compostos, principalmente, por mistura de solos e outros tipos de RCC. Materiais cimentícios estão presentes em todas as frações granulométricas das amostras. As propriedades geotécnicas dos solos de escavação não são prejudicadas pela mistura com outros tipos de RCC. Os materiais são basicamente granulares e bem graduados, com resistência mecânica adequada para algumas aplicações geotécnicas ou de pavimentação. Nitrato e sulfato dissolvidos podem poluir aquíferos e águas superficiais; entretanto, as concentrações observadas não representam risco à saúde. No caso de concentrações superiores aos valores máximos permitidos pela regulamentação de resíduos, a avaliação do risco a possíveis receptores deve ser efetuada conforme o uso pretendido da construção. Foi sugerido um critério preliminar de triagem de materiais de escavação para potenciais reusos na RMSP. / Considering the need of sustainable solutions for disposal of excavation soils from construction works in urban areas, this study presents characterization of excavation materials received in a CDW landfill located in the Metropolitan Region of São Paulo (MRSP). Samples were visually classified as predominantly excavation soil or mixtures of different types of CDW, and submitted to chemical, mineralogical, environmental and geotechnical characterization tests. The excavation material disposed of in the landfill is mainly composed of a mixture of soils and other types of CDW. Cementitious materials are present in all grain size fractions. Geotechnical properties of excavation soils are not impaired by the mixture with other types of CDW. The materials were basically granular and well-graded, with appropriate mechanical resistance for some geotechnical or pavement applications. Dissolved nitrate and sulfate may pollute aquifers and superficial waters; however, the observed concentrations do not represent health concern. In the case of concentrations higher than the maximum allowed values, risk assessment to possible receptors shall be carried out according to the intended construction purpose for potential reuse screening. A preliminary criteria screening for potential reuses was suggested for excavation materials of the MRSP.
165

Influência do laser de Er:YAG e da broca de cerâmica na microtração de um sistema adesivo autocondicionante em dentina desmineralizada após envelhecimento / Influence of Er: YAG laser and ceramic bur on the micro-tensile bond strength of a self-etch adhesive system in demineralized dentin after aging

Cintia Guimarães de Almeida 18 March 2016 (has links)
Este estudo avaliou a influência do laser de Er: YAG e da broca de cerâmica em baixa rotação na adesão de um sistema adesivo autocondicionante na dentina desmineralizada após envelhecimento. Oitenta terceiros molares humanos hígidos tiveram suas raízes e seus terços oclusais seccionados. As câmaras pulpares foram preenchidas com resina composta e a dentina foi desgastada com lixas de granulação decrescente para padronização da smear layer. Os espécimes foram isolados com esmalte cosmético ácido resistente para a indução de cárie artificial. Após 28 dias de ciclagem de pH, os espécimes foram aleatoriamente divididos em quatro grupos, de acordo com o método de remoção do tecido cariado: (WR) sem remoção, (L) Laser de Er: YAG, (B) Broca Carbide em turbina de baixa rotação, (C) Broca de Cerâmica em turbina de baixa rotação. Após a remoção do tecido cariado, os espécimes foram restaurados com o adesivo autocondicionante Clearfil SE Bond e restaurados com resina composta Filtek Z 350. Os espécimes permaneceram em estufa a 37°C durante 24 horas e então foram seccionados para produzir palitos com área de secção transversal de 1 mm². Cada grupo foi dividido em dois grupos antes do envelhecimento (NA) sem envelhecimento e (H) imersão em hipoclorito de sódio 10% por três horas compondo oito grupos (n = 10) WRNA, LNA, BNA, CNA, WH, LH, BH e CH. Os espécimes foram submetidos ao teste de microtração em máquina universal de testes com velocidade de 0.5 mm/min (MPa). A classificação dos padrões de fratura foi realizada com lupa estereoscópica com aumento de 90 X. O teste não paramétrico de Kruskal-Wallis 5% demonstrou significância estatística para a interação entre os fatores analisados (remoção do tecido cariado e envelhecimento). O teste complementar de Mann-Whitney 5%, demonstrou que os maiores valores de resistência adesiva foram observados quando o tecido cariado foi removido com o método convencional utilizando a turbina de baixa rotação, tanto para a broca carbide (BNA) como para a broca de cerâmica (CNA) sem envelhecimento, que foram diferentes estatisticamente dos demais grupos. Após o envelhecimento, a broca de cerâmica (CH) obteve o melhor resultado e foi estatisticamente similar à broca carbide (BH). O grupo BH foi estatisticamente similar ao laser de Er:YAG, com (LH) ou sem (LNA) envelhecimento, e ao tecido desmineralizado com envelhecimento (WRH) que foram os menores valores obtidos. A broca de cerâmica em turbina de baixa rotação influenciou negativamente a resistência adesiva do adesivo autocondicionante após envelhecimento e o laser de Er: YAG influenciou negativamente a resistência do adesivo autocondicionante em ambas as condições testadas. / The purpose of this study was to evaluate the influence of Er: YAG laser and conventional method of caries removal employing ceramic bur on the bond strength of a self-etching system in demineralized dentin after aging. Eighty recently extracted non-carious human third molars were cut and ground to expose a flat dentin surface. Each tooth was submmited to pH cycles to produce artificial caries affected dentin. The specimens were divided according to the method of caries removal: (WR) without removal, (L) Er: YAG laser, (B) Carbide bur at low speed, (C) Ceramic bur at low speed. After that, the specimens were restored with a self-etch adhesive system (Clearfil SE Bond) and composite resin (Filtek Z 350). The restored teeth were stored in distilled water at 37°C for 24 hours and thereafter-sectioned perpendicular to the bonded interface with a refrigerated low-speed diamond disc to produce sticks 1 mm² crossseccional area. Then, each group was divided into two groups before aging in 10% sodium hypocloride (n = 10): NA (No aging) WRNA, LNA, BNA, CAN and H (immersion in 10% sodium hypocloride for 3 hours) WRH, LH, BH, CH. The microtensile bond strength (microTBS) test was performed in a universal test machine with a crosshead speed of 0.5 mm/minute. Bond strengths were calculated in MPa and analyzed by Kruskal-Wallis and Mann-Whitney at a 0.05 level of significance. Failure patterns were examined with a stereomicroscope. The results showed that there were statistical significance for the interaction between the factors analyzed (removal of decayed tissue and aging). The highest bond strength values were observed for both ceramic bur (CNA) and carbide bur (BNA) without aging, which were statistically different from the other groups. After aging, the ceramic bur (CH) and carbide bur (BH) were statistically similar and showed the highest TBS values. Ceramic bur at low speed seemed to be a conservative alternative for the removal of carious tissue and more studies are necessary to establish a more favorable bond strength over time using self-etch adhesive systems
166

Analys av deformationsutveckling under framdrift av tunnlar

Hellberg, Jennifer January 2020 (has links)
Idag används ofta ett samband, framtaget av Hanafy och Emery (1980), för att uppskatta deformationer vid tunnelfronten då bergförstärkning ska installeras i närheten av tunnelfronten. Sambandet visar hur deformationerna i ett referensplan utvecklas som en funktion av tunnelfrontens avstånd till referensplanet. I det här examensarbetet studerades deformationsutvecklingen i en tunnel med syftet att utvärdera hur tunnelgeometri, bergtäckning, spänningsfält och bergkvalitet påverkar deformationsutvecklingen under framdriften. I examensarbetet studerades även bergförstärkning under framdriften med syftet att jämföra resultat när hänsyn tagits till sprutbetongens härdningstid relativt när full styvhet antagits direkt vid installation samt studera belastning i bergbultar. Studien visade att analysresultat och samband framtaget av Hanafy och Emery kan återskapas med FLAC3D. Kombination av förändrat spänningsfält, tunneltvärsnitt och/eller bergtäckning medförde att deformationsutvecklingen inte följde sambandet. Resultatet kunde generaliseras till alla fall skilt från ett hydrostatiskt spänningsfält. Baserat på studien rekommenderas att sambandet enbart bör användas när hydrostatiskt spänningsfält och elastiskt materialbeteende kan antas för att uppskatta deformationer i närheten av tunnelfronten. Tredimensionell modellering i närheten av tunnelfronten rekommenderas alltid utföras när spänningsfält ej kan antas hydrostatiskt. Detta för att på ett korrekt sätt uppskatta deformationer och spänningar kring tunneln. Simulering av bergförstärkning bör genomföras baserat på verklig uttagssekvens med projektspecifika indata för att belastningshistorik och deformationer ska kunna uppskattas och användas som grund för dimensionering. / Currently, a correlation developed by Hanafy and Emery (1980), is often used to estimate deformations at the tunnel face for projects where rock reinforcement is to be installed near the tunnel face. It shows how deformations at a reference plane develops as a function of the distance to the tunnel face. In this thesis, the displacements was studied in order to investigate how tunnel geometry, rock coverage, stresses and rock quality affected the accumulation of displacements in a tunnel during excavation. Studies of rock reinforcement were conducted with purpose to compare results from simulations when the shotcrete hardening process had been considered and when maximum stiffness was assumed directly at installation. Load in bolts was also studied. The study showed that elastic analyses with FLAC3D can recreate analysis results and correlation developed by Hanafy and Emery. Combinations of changed stress field, tunnel geometry and/or rock cover resulted in three-dimensional effects which gave a different displacement ratio compared to Hanafy and Emery. This could be generalised to all cases in which the stress field differed from a hydrostatic stress field. Based on the study it is recommended to only use the correlation for estimating displacements near a tunnel face when hydrostatic stress field and elastic material behaviour can be assumed. Three-dimensional modelling should always be carried out in cases where the stress field cannot be assumed hydrostatic in order to correctly estimate displacements and stresses around the tunnel in the vicinity of the tunnel face. Simulation of rock reinforcement should be carried out based on the actual excavation sequence that will take place. Simulations should be performed with project-specific input data so that load history and displacements can be estimated properly and used in design.
167

Bits & Bobs : Finds from a research excavation of Birka’s rampart: A study with focus on material distribution and metal conservation

Heljeback, Mikael January 2019 (has links)
In the spring of 2018, a prospection and subsequent research excavation of a previously unstudied area related to the rampart of the Viking age town of Birka, Sweden, was undertaken by students and professors from the archaeological science department affiliated with Stockholm University.The purpose of this paper is to examine and categorise the various excavated finds, the ensuing conservation and preservation of the metal objects as well as to investigate the context and possible function of the site regarding the spatial distribution of said finds.The main method used is that of metal conservation with the wet-chemical technique EDTA; a method that was deemed adequate for the treatment of the dry metal finds from the rampart excavation.The conservation and categorisation suggest that the metal posts consist of assorted metal objects, predominately rivets and nails as well as unidentified fragmented objects; the occasional slag fragment was evident. The material category of clay and ceramics contains assorted burnt clay and ceramic sherd fragments, some with decoration. Whetstone (or hone stone) and flint fragments make up most of the stone finds while the category of glass consists of a few bead fragments. The bulk of the osteological material consists of burnt and unburnt animal bones, some with slaughter marks in the form of cuts and hacks. Two human bone fragments were found; a humerus- and cranial fragment.Post holes and charcoal in the context of the rampart suggests the possibility of wooden supports and/or a superimposed wooden structure on the rampart itself that likely burnt at some point in time. The interpretation of the excavated area, based on the distribution of the finds and material categories, is that of a dumping site for discarded town refuse, most likely set against or near a walled construction; the rampart. The dating of the site is based on object similarities as well as stratigraphy and set to; Early to Late Viking Period, c. A.D. 820-1000(1150).The analyses, materials and the stratigraphy of the site together with a contextual analysis of the objects in question furthers the knowledge of Birka’s rampart and will enable future scientific inquiries into this specific rampart as well as similar fortification structures.
168

Konstruktion av serviceutrustning till tunnelborrningsmaskin / Design of service equipment for a tunnel boring machine

ENGSTRÖM, JON January 2013 (has links)
The Master Thesis work this report is based upon has been conducted in cooperation with Svea Teknik AB. Svea Teknik is a consultant firm which is developing parts of a tunnel boring machine on behalf of Atlas Copco. The machine is being developed to mechanically excavate hard rock by fixating itself in the tunnel and then press a large rotating cutter-wheel equipped with disc-cutters against the tunnel wall. The disc-cutters are the tools that are in direct contact with the hard rock and are therefore exposed to extensive wear and needs to be replaced on a regular basis.The purpose of this Master Thesis has been to develop a service equipment that will enable time effective and safe changes of disc-cutters. The disc-cutters have a diameter of 17 inches and weigh about 130 kg. The available space in the tunnel is very limited which puts strict requirements on the size of the service equipment.A specification of requirements was set up based on the background study made in the Master Thesis. Concepts to solve the problem were then generated and evaluated against each other.A concept consisting of a wagon with three slots for disc-cutter transport, a foldable crane with a hoist and a lifting tool adapted to the disc-cutters were chosen for further development. Since the concept was quite extensive the decision was made to focus the work around the lifting tool.By loading new disc-cutters onto the driven wagon together with the foldable crane and the lifting tool, the equipment can be transported past the machine in the tunnel and the crane can then be set up in front of the machine's cutter-wheel. The lifting tool is then lifted by the hoist to enable the disc-cutters in the cutter-wheel to be replaced.The lifting tool consists of two claws that close around the disc-cutter to fixate it geometrically and a counter weight to enable easy positioning of the disc-cutter by hand. The lifting tool is dimensioned according to two different load cases and was verified by FE-analysis.Recommendations for future work and more detailed design were set up. / Examensarbetet denna rapport baseras på, har utförts i samarbete med Svea Teknik AB. Svea Teknik är ett konsultföretag som på uppdrag av Atlas Copco utvecklar delar av en gruvmaskin för tunnelborrning. Maskinen konstrueras för att mekaniskt krossa berget genom att fixera sig i tunnelgången och pressa ett stort skärhjul utrustat med diskformade s.k. kuttrar mot bergväggen samtidigt som skärhjulet roterar. Då kuttrarna är de verktyg som står i direkt kontakt med berget slits de markant och måste bytas ut för service med jämna mellanrum.Detta examensarbete har syftat till att utveckla en serviceutrustning för att möjliggöra snabba och smidiga byten av dessa kuttrar som har en diameter på 17 tum och väger ca 130 kg. Då utrymmet i tunneln är väldigt begränsat finns stora krav på utrustningens storlek.En kravspecifikation, baserad på examensarbetets bakgrundsstudie, utarbetades för att ligga till grund för de genererade koncept som sedan utvärderades gentemot varandra.Efter att ett koncept bestående av en transportvagn med plats för tre kuttrar, en vikbar kran med telfer samt ett specialanpassat kloförsett lyftverktyg hade valts togs beslutet att fokusera arbetet kring lyftverktyget för att begränsa projektets omfång.Genom att lasta nyservade kuttrar på den drivna transportvagnen tillsammans med den hopvikta kranen och lyftverktyget kan den ledas fram förbi maskinen i tunneln och kranen monteras upp framför maskinens skärhjul. Lyftverktyget hängs sedan upp i kranen för att möjliggöra att kuttrar lossas respektive monteras.Lyftverktyget består av två klor som sluts runt kuttern för att fixera den formbetingat samt en motvikt för att för hand kunna ändra rotationen av verktyget kring infästningspunkten. Lyftverktyget dimensionerades utifrån två uppsatta lastfall och verifierades sedan med FEM-analyser
169

Rekonstrukce kanalizace v Brně / Reconstruction of sewer in Brno-City

Folovská, Kateřina January 2012 (has links)
The master thesis deals with the reconstruction of the sewerage in Brno-city, between the streets Roosveltova and Solniční. Due to the location of sewer in build-up area, the reconstruction will be performed by tunnelling technology – shield excavation. The thesis is mainly dedicate with design and structual design of sewer lining. The mathematical model is created in software Plaxis 8.2 2D.
170

Jämförelse mellan grundläggningsmetoder för lera med begränsat djup / Comparison between different foundation methods for clay with limited depth.

Ekström, Isak, Lutfiu, Taulant January 2023 (has links)
This thesis compares foundation methods for buildings on low-strength, limited-depth soil. The study focuses on soil replacement and piling, specifically concrete and steel piles. The studyaims to answer the key questions about the possibility to use short piles on limited depth, cost-efficiency, and environmental impact of these methods. Geotechnical and structural calculations are used to assess the loads on the piles and evaluate their strength. WIN-statik Frame Analysis helps analyze deformations, moments, and stresses. The foundation transfers vertical loads to three piles, generating horizontal loads at the pile tops. However, the challenge lies in short piles in clay, which experience low earth pressure and may rotate due to bad stabilization. The analysis reveals that concrete piles are unable to transfer loads to solid rock effectively. Without fixed anchorage points, they are prone to rotation due to insufficient stiffness and lateral earth pressure. In contrast, steel piles are preferred because they can be drilled into the rock, providing fixed anchorage at the clay-rock transition and enabling them to withstand loads transferred through the foundation. Soil replacement is considered as an alternative method but proves economically expensive, approximately three times more than piling with steel piles. From an environmental standpoint, piling contributes only slightly more carbon dioxide emissions, about 0.4 tons, compared to soil replacement. Considering the significant cost advantage and minor environmental impact difference between soil replacement and piling, piling with steel piles is recommended as the optimal foundation method. Concrete piles are dismissed due to their instability. This choice ensures stability, cost-efficiency, and reduced environmental impact for buildings on low-strength, shallow-depth soil.

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