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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.
41

Propriedades vibracionais e estruturais de cadeias lineares de carbono / Vibrational and structural properties of linear carbon chains

Andrade, Nádia Ferreira de January 2015 (has links)
ANDRADE, Nádia Ferreira de. Propriedades vibracionais e estruturais de cadeias lineares de carbono. 2015. 213 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2015. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-10-26T18:07:30Z No. of bitstreams: 1 2015_tese_nfandrade.pdf: 12228920 bytes, checksum: 9f6aef6ce2c60c7d88f7ecb59b39e43f (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-10-26T18:14:26Z (GMT) No. of bitstreams: 1 2015_tese_nfandrade.pdf: 12228920 bytes, checksum: 9f6aef6ce2c60c7d88f7ecb59b39e43f (MD5) / Made available in DSpace on 2015-10-26T18:14:26Z (GMT). No. of bitstreams: 1 2015_tese_nfandrade.pdf: 12228920 bytes, checksum: 9f6aef6ce2c60c7d88f7ecb59b39e43f (MD5) Previous issue date: 2015 / We present a study of linear carbon chains encapsulated in multi-wall carbon nanotubes (Cn@MWCNT) using electron microscopy and Raman spectroscopy in ambient and extreme conditions. The linear chains were characterized by resonance Raman, thermal analysis, ion bombardment and using high resolution and scanning transmission electron microscopy. The HRTEM images obtained here shown the chain within the innermost MWCNT and in this work we obtain the first image of ``cross-section$"$ described for this system Cn@MWCNT. A Raman experiment was carried out in high pressure conditions (from 0 to 9.54 GPa) using a paraffin oil as pressure transmitting medium.The G band frequency of nanotube increase as pressure increase while the C-C stretching mode of linear carbon chain decreases. Theoretical results based on atomistic simulations allowed an understanding of vibrational behavior of the chains. Furthermore, we conducted works that involved instrumentation in order to set in the Department of Physics of the Federal University of Ceara, the instrumentation needed for the development of a device that enables to perform Raman spectroscopy and AFM measurements. For this purpose is necessary to integrate a scan-head, a controller system that controls the probe scan-head and an optical system that communicates with an APD (avalanche photodiode device), responsible for carrying the images with a spectrometer dedicated for obtaining Raman spectra. The system is functional as regards the ability to perform confocal measurements and ready for setting the near field measurements. / Apresentamos um estudo de cadeias lineares de carbono encapsuladas em nanotubos de carbono de paredes múltiplas (Cn@MWCNT) utilizando microscopia eletrônica e espectroscopia Raman em condições ambientes e extremas. As cadeias lineares foram caracterizadas por espectroscopia Raman ressonante, análise térmica, bombardeamento de íons e com microscopia eletrônica de transmissão. As imagens de alta resolução aqui obtidas mostraram a presença das cadeias dentro do tubo mais interno do MWCNT e neste trabalho obtivemos a primeira imagem de "seção transversal" descrita na literatura para um sistema deste tipo. Um experimento Raman foi conduzido em condições de altas pressões (0 - 9,54 GPa), utilizando um óleo de parafina como meio transmissor de pressão. A frequência da banda G dos nanotubos aumentou com o aumento da pressão enquanto o modo de estiramento C-C das cadeias de carbono lineares diminuiu. Resultados teóricos baseados em simulações atomísticas permitiram uma compreensão do comportamento vibracional da cadeia. Além disso, realizamos trabalhos que envolveram instrumentação afim de instalar no Departamento de Física da Universidade Federal do Ceará toda a instrumentação necessária para o desenvolvimento de um equipamento que permite realizar espectroscopia Raman e medidas de microscopia de força atômica (AFM). Para isto, é necessário integrar uma "scan-head", um sistema controlador que controla a sonda da "scan-head" e um sistema óptico que se comunica com uma APD (dispositivo fotodiodo avalanche) responsável pela aquisição das imagens, com um espectrômetro dedicado à obtenção dos espectros Raman. O sistema ficou funcional no que diz respeito a capacidade de executar medidas confocal e está pronto para a realização de medidas de campo próximo.
42

Hydrologické simulace odtoků vody z povodí při srážko-odtokových událostech / Event-based rainfall-runoff modelling of the selected river basin

TICHÁČEK, Pavel January 2018 (has links)
This thesis deals with the event-based rainfall-runoff modelling of the selected river basin. This thesis is based on my previous work "Factors affecting the water discharge from the river basin during rainfall-runoff events". In that work I described factors, which have effect on water runoff from the river basin. This thesis was solved on basin of Jílecký stream. Water runoff from basin is affected with a number of factors, the most significant are slope of the terrain, soil saturation, geological and pedological conditions, vegetation cover and anthropogenic influence. Calculations of direct runoff were realised with method of CN curves, with using BPEJ map, land use map gained from Corine Land Cover 2006 and maximum daily precipitation sums with 2, 10, 20, 50 and 100 years probabilities recurrence obtained from the rainfall station Netřebice. Calculations were performed in a numerical method using vector data and a raster method performed in ArcMap. In the next step I performed simulations of various scenarios of change in river basic characteristics such as soil saturation change, grassing of arable land with a slope greater than 12°, grassing of all arable land and enlargement the built-up area in the river basin.
43

Vibrational and structural properties of linear carbon chains / Propriedades vibracionais e estruturais de cadeias lineares de carbono

NÃdia Ferreira de Andrade 26 August 2014 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / We present a study of linear carbon chains encapsulated in multi-wall carbon nanotubes (Cn@MWCNT) using electron microscopy and Raman spectroscopy in ambient and extreme conditions. The linear chains were characterized by resonance Raman, thermal analysis, ion bombardment and using high resolution and scanning transmission electron microscopy. The HRTEM images obtained here shown the chain within the innermost MWCNT and in this work we obtain the first image of ``cross-section$"$ described for this system Cn@MWCNT. A Raman experiment was carried out in high pressure conditions (from 0 to 9.54 GPa) using a paraffin oil as pressure transmitting medium.The G band frequency of nanotube increase as pressure increase while the C-C stretching mode of linear carbon chain decreases. Theoretical results based on atomistic simulations allowed an understanding of vibrational behavior of the chains. Furthermore, we conducted works that involved instrumentation in order to set in the Department of Physics of the Federal University of Ceara, the instrumentation needed for the development of a device that enables to perform Raman spectroscopy and AFM measurements. For this purpose is necessary to integrate a scan-head, a controller system that controls the probe scan-head and an optical system that communicates with an APD (avalanche photodiode device), responsible for carrying the images with a spectrometer dedicated for obtaining Raman spectra. The system is functional as regards the ability to perform confocal measurements and ready for setting the near field measurements. / Apresentamos um estudo de cadeias lineares de carbono encapsuladas em nanotubos de carbono de paredes mÃltiplas (Cn@MWCNT) utilizando microscopia eletrÃnica e espectroscopia Raman em condiÃÃes ambientes e extremas. As cadeias lineares foram caracterizadas por espectroscopia Raman ressonante, anÃlise tÃrmica, bombardeamento de Ãons e com microscopia eletrÃnica de transmissÃo. As imagens de alta resoluÃÃo aqui obtidas mostraram a presenÃa das cadeias dentro do tubo mais interno do MWCNT e neste trabalho obtivemos a primeira imagem de "seÃÃo transversal" descrita na literatura para um sistema deste tipo. Um experimento Raman foi conduzido em condiÃÃes de altas pressÃes (0 - 9,54 GPa), utilizando um Ãleo de parafina como meio transmissor de pressÃo. A frequÃncia da banda G dos nanotubos aumentou com o aumento da pressÃo enquanto o modo de estiramento C-C das cadeias de carbono lineares diminuiu. Resultados teÃricos baseados em simulaÃÃes atomÃsticas permitiram uma compreensÃo do comportamento vibracional da cadeia. AlÃm disso, realizamos trabalhos que envolveram instrumentaÃÃo afim de instalar no Departamento de FÃsica da Universidade Federal do Cearà toda a instrumentaÃÃo necessÃria para o desenvolvimento de um equipamento que permite realizar espectroscopia Raman e medidas de microscopia de forÃa atÃmica (AFM). Para isto, à necessÃrio integrar uma "scan-head", um sistema controlador que controla a sonda da "scan-head" e um sistema Ãptico que se comunica com uma APD (dispositivo fotodiodo avalanche) responsÃvel pela aquisiÃÃo das imagens, com um espectrÃmetro dedicado à obtenÃÃo dos espectros Raman. O sistema ficou funcional no que diz respeito a capacidade de executar medidas confocal e està pronto para a realizaÃÃo de medidas de campo prÃximo.
44

Návrh opatření pro ochranu zastavěného území před povrchovým odtokem z přívalových srážek v k.ú Studénka / Proposal for measures for the protection of the built area from the surface runoff from the torrential precipitation in the village of Studénka

Horáková, Věra January 2019 (has links)
This thesis investigates the design of complex systems measures against water erosion in cadastral areas Bílov, Butovice, Studénka and Velké Albrechtice. By using erosion and hydrological GIS tools, the area was explored and analyzed and based on these output values the best solution was proposed. To identify areas at risk of erosion and runoff conditions were used a digital elevation model, Wischmeier-Smith equation and model DesQ. At the end was evaluated effectiveness by comparing the results before and after measures.
45

A GIS-Based Method of Deriving Spatially Distributed Unit Hydrographs / En GIS-baserad metod för att beräkna  spatialt fördelade enhetshydrografer

Lenander, Ann-Sofi January 2021 (has links)
Prior to using hydraulic and spatially distributed modelling softwares, the theory of the unit hydrograph was a commonly used tool for modelling of surface and runoff water. While distributed models often provide detailed results from extensive calculation durations, the unit hydrograph have been questioned for simplifying the physical characteristics of the watershed modelled. Typically, the unit hydrograph theory does not explicitly take the flow paths of the watershed in consideration during calculation. With the rise of geographical information systems, methods of deriving spatially distributed unit hydrographs have been developed. The aim of these have commonly been to find a spatially varied form of hydrological modelling, while still keeping the computation times low. The method is commonly built by calculating the travel time to the watershed outlet along the flow path. In this study, spatially distributed unit hydrographs are derived separately for the watershed’s pervious and impervious surfaces in a Python script using map algebra and the Esri’s Python wrapper module Arcpy. The travel times are generated from a velocity field calculated using Maidment and Olivera’s velocity equation. The velocity equation contains three unknown parameters; one for an average velocity and two calibration parameters. The excess precipitation is calculated of a 100 year return period Chicago Design Storm hyetograph using the SCS-CN method. The direct runoff hydrographs are calculated over three semi-urban watersheds in Smedby in southern Sweden, and the results are compared to MIKE 21 hydrograph data of each corresponding watershed and rain input. The result obtained showed to replicate the hydrograph response quite well, but only if the unknown parameters in the velocity equation were calibrated to match the MIKE 21 data. The unknown parameters of the velocity equations produces uncertainties of using the method without calibration data, which implies that the script is not well adapted to use for modelling predictions. It may be of interest to calculate the travel times of the locations within the watershed using a different formula. The script tool could be tested using different design storms as input, and areas of different characteristics compared to Smedby could be tested. / Innan det blev vanligt att använda hydrauliska och rumsliga modellerings- mjukvaror användes ofta teorin bakom enhetshydrografen för modellering av avrinning. Medan de rumsliga mjukvarorna ofta erbjuder detaljerade resultat till priset av långa beräkningstider, har enhetshydrografen ifrågasatts för att förenkla den fysiska karaktären av avrinningsområdet. Typiskt sett tar inte enhetshydrografen avrinningsområdets flödesvägar direkt i hänseende vid beräkning. Utveckling och ökad tillgänglighet av geografiska informations- system förenklade möjligheterna att utveckla beräkning av enhetshydrografer som tar hänsyn till avrinningsområdets karaktär, typiskt sett genom att beräkna rinntiden från varje läge i avrinningsområdet, längs rinnvägarna och till utloppet. I den här studien beräknas spatiala enhetshydrografer separat för avrinningsområdets hårdgjorda och icke hårdgjorda ytor, genom att utveckla ett Python skript med hjälp av karalgebra och Esri’s wrapper modul ArcPy. Rinntiderna från olika lägen i avrinningsområdet beräknas med Maidments och Oliveras formel för hastighet, vilken innehåller okända parametrar för en uppskattad medelhastighet samt två kalibreringsparametrar. Effektivt regn från ett Chicago Design Storm regn med en återkomsttid på 100 år beräknas med hjälp av SCS-CN metoden. Hydrograferna för direkt avrinning faltas för tre semi-urbana avrinningsområden i Smedby i södra Sverige för att sedan jämföras mot MIKE 21 genererad hydrograf data för respektive motsvarade avrinningsområde. Hydrografdata producerat av MIKE 21 har tagits fram med lika CDS-regn data som input. Resultatet visar att hydrografer snarlika MIKE 21 hydrograferna kan tas fram med Maidments spatialt fördelade enhetshydrograf, om de okända parametrarna i Maidments formel kalibrerades mot MIKE 21 data. Utan kalibreringsdata för att bestämma de okända parametrarna kan resultatet anses vara mycket osäkert, vilket antyder att Python skriptet ej bör användas för använda metoden för att förutspå responser av regnevent. Andra beräkningar än Maidments ekvation kan vara av intresse att implementera. Olika typer av regninput samt spatial data över andra platser än Smedby kan vara av intresse att testa Python skriptet för.
46

The numismatic iconography of the period of iconomachy (610-867)

Vrij, Maria Chantal January 2018 (has links)
This thesis considers the use of numismatic imagery in the Byzantine Empire during the period 610-867, with its main focus centred in the period 685-842. Though charting the iconographic trends and changes on the coinage of the period and the possible reasons behind them is the principal raison d’être of the thesis, it also tackles methodological issues such as the use and abuse of dies studies and ways of determining who decided what images appeared on coins. The main body of the text is arranged chronologically with the methodological issues appearing throughout. Exceptions to this format are the first chapter, which considers the economic context of coin circulation in the period and the gold purity of the coins of the period, and the third chapter, which considers the production at the mint of Cherson, which produced anonymous coins not identifiable by date, but still part of the context. Finally, the thesis contains two appendices, the first paper appendix presents a catalogue of the coins held at the Barber Institute of Fine Arts for the period 685-842, and the second CD-ROM appendix presents the data from the All That Glitters ... project, testing the purity of Byzantine gold coins with x-ray fluorescence.
47

Latin 'basilissai' in Palaiologan Mystras : art and agency

Mattiello, Andrea January 2018 (has links)
This dissertation demonstrates that the presence of Latin basilissai, Catholic wives of the Byzantine despots of Morea, in Mystras between 1349, when the city became the seat of the Despotate, and 1460, when it was surrendered to the Turks, had an impact on the artistic and cultural production at court. These foreign women were agents of the ruling political and economic elites of Italian and Frankish courts, and expressed their agency by mediating their specific cultural and artistic traditions into the production of their adopted city. Art and cultural historical approaches, in which attention is focused on painted and sculpted details, inscriptions, archaeological remains, architectural design, and urban planning, are used to show that the Latin women were historical agents, whose presence can be detected in Mystras. A multidisciplinary analysis of case studies reveals cross-cultural motifs in the artistic production, demonstrating the relationship between pieces of evidence. The production of the workshops of Mystras expressed features that were, in some cases, responses to Constantinopolitan and Byzantine models, while, in others, autonomous and innovative, revealing complex cross-cultural references. Ultimately, this study shows that the particular cultural and artistic landscape of Mystras is indebted to exogenous cultures linked to these women.
48

Ethnicity and statehood in Pontic-Caspian Eurasia (8-13th c.) : contributing to a reassessment

Feldman, Alex January 2018 (has links)
What is the line between the “ancient” world and the “medieval” world? Is it 476? 330? 632? 800? Most historians acknowledge there is no crisp line and that these are arbitrary distinctions, but they are made anyway, taking on lives of their own. I believe they are much the same world, except for the pervading influence of one flavor of monotheism or another. This thesis endeavors to study top-down, monotheistic conversions in Pontic-Caspian Eurasia and their respective mythologizations, preserved both textually and archaeologically, which serve as a primary factor for what we might call “state formation.” These narratives also function, in many cases, as the bases of many modern nationalisms, however haphazard they may be. I have attempted to apply this idea to Christian Rome (Byzantium)’s diachronic missionary policy around the Black Sea to reveal how what we today call the “Age of Migrations” (the so-called “Germanic” invasions of the Roman Empire), was actually in perpetual continuity all the way up to the Mongolian invasions and perhaps even later. In this way, I hope to enhance the context by which we understand the entirety of not only Western history, but to effectively bind it to a broader context of global monotheization.
49

Subcloning, Expression and Purification of Functional E. coli Nucleotide Excision Repair Protein UvrA Using IMPACT-CN System

Lin, Cathy W, Mrs 01 May 2014 (has links)
DNA in cells is constantly damaged by both endogenous and exogenous genotoxic agents. DNA repair is a cellular machinery that counters DNA damage and thus preserve genome integrity. Nucleotide excision repair (NER) in Escherichia coli (E. coli) is one of the DNA repair systems that recognizes and removes a variety of DNA damage such as pyrimidine dimers, bulky chemical adducts, DNA intrastrand cross-links, etc. The genes responsible for E. coli NER incisions are UvrA, UvrB, and UvrC. As the first step of E. coli NER, DNA damage recognition is achieved through the UvrA2B complex. Purification of UvrA, UvrB, and UvrC is essential for research to understand the molecular mechanisms of NER and carcinogenesis. Although UvrA, a 115 kDa protein, has been successfully purified in our lab in the past, the experimental procedures were very time-consuming and technically challenging. In this study we employed IMPACT (Intein Mediated Purification with an Affinity Chitin-binding Tag) system to subclone the cDNA of UvrA and express and purify the recombinant UvrA protein by a single-column step using the cloned expression construct. Furthermore, the purified protein was found to be fully functional in the UvrABC incision assay in which the DNA adduct of FABP [N-(20-deoxyguanosin-8-yl)-4-fluoro-4-aminobiphenyl] was efficiently cleaved in a time course-dependent manner.
50

Vliv časového rozložení srážkového úhrnu na hydrologické charakteristiky srážko-odtokové události / The influence of temporal rainfall distribution on hydrological characteristics of rainfall-runoff events

MIKOLÁŠOVÁ, Anna January 2017 (has links)
This master thesis deals with the influence of temporal distribution of precipitation on hydrological characteristics of the rainfall-runoff process. The practical part of the thesis was carried out on the drainage basin Volšovka. In the theoretical part, the origin, division, and temporal distribution of rainfall is described, as well as surface runoff and some chosen hydrological characteristics of flow-off. Moreover the work deals with hydrological simulation, there is also described in further detail the rainfall-runoff model HEC-HMS, which is furthermore used in the practical part of this thesis. In the practical part, the characteristics of the area of interest is introduced. Next is described the preparation of the rainfall data with the use of DES_RAIN programme, also creation of the digital model of the terrain in the ArcGIS programme and the preparation of hydrological model in HEC-HMS model. In the conclusion of the thesis, the flow capacities of the closure profile of Volšovka were simulated, as well as other particular closure profiles of the catchment area. There were 16 simulations carried out, which were evaluated on the basis of the peak flow capacities and the time of culmination.

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