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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.
11

Sm-Nd and C-isotope chemostratigraphy of Ordovician epeiric sea carbonates, midcontinent of North America

Fanton, Kerrie C. 04 January 2005 (has links)
Interpreting and correlating epeiric sea sequences is key to understanding ancient marine environments. As a result, eNd, d13C and Sm/Nd profiles are developed as tools for interpreting epeiric sea carbonates. Previously, eNd and d13C profiles in epeiric sea carbonates have been used to study changes in the Nd isotope balance and C-cycle of adjacent ocean water. Instead, eNd, d13C and Sm/Nd profiles of Ordovician Midcontinent carbonates of North America demonstrate that fluctuations in sea level and depth are driving local changes in the eNd, d13C and Sm/Nd composition of epeiric seawater. <p> Dissolved Nd derived from the Transcontinental Arch, Taconic Highlands and the Iapetus Ocean determine the eNd composition of Midcontinent seawater. As sea level fluctuated, submergence of the Arch and an influx of Iapetus ocean waters adjusted the Nd isotope balance of epeiric seawater. As a result, eNd profiles can be used to track the submergence history of the Late Ordovician Midcontinent. Comparison of stratigraphic variations in carbonate Sm/Nd ratios with sea level curves, conodont paleoecology, and the eNd profiles also suggests that variations in Sm/Nd ratios are related to changes in depth. However, processes effecting Sm/Nd ratios in epeiric seas may be varied and require further investigation. <p> Sea level fluctuations and the waxing and waning of cool, nutrient rich, oxygen poor Iapetus waters onto the craton adjusted productivity and organic carbon burial rates on the Ordovician Midcontinent. Close to the Transcontinental Arch sea level rise caused an increase in organic carbon burial and productivity, while close to the Sebree Trough, and the influx of Iapetus waters, sea level rise caused a decrease in organic carbon burial and productivity. Differences in local C-cycling across a single epeiric sea encourage caution when using d13C profiles from epeiric sea carbonates to track changes in the C-cycle of adjacent oceans. <p> Because of their connection to sea level fluctuations, variations in the eNd, d13C and Sm/Nd profiles can also used to correlate Ordovician Midcontinent carbonates. However, the ability to correlate coeval strata using these profiles is limited by changes in depositional environment across the craton, which cause excursions to be absent, dampened, or magnified.
12

I skuggan av NHL : en organisationsstudie av svensk och finsk elitishockey

Backman, Jyri January 2012 (has links)
I denna licentiatuppsats har svenska elitseriens respektive finska SM-liigas seriemodeller analyserats i ljuset av NHL:s dominans över den globala ishockeyn. Bakgrunden till problemområdet är att företrädarna för svensk respektive finsk elitishockey implementerat olikartade organisatoriska lösningar, trots att de utvecklats i kontexter med likartade sportmodeller och samhällsvillkor. Metodologiskt bygger denna licentiatuppsats på komparativa studier. Som grund för min analys har jag använt mig av dokumentanalys med inslag av rättsdogmatik. Den teoretiska ramen har utgjorts av historikern Martin Alms amerikaniseringsbegrepp samt juristen och forskaren Lars Halgreens analys om amerikaniseringen av europeisk sport. Följande frågeställningar har analyserats: Hur har elitserien respektive SM-liiga utvecklats i relation till den amerikanska respektive europeiska sportmodellen, sedan 1970-talets mitt? Vilka kännetecken kan fastställas för de respektive organisationsmodellerna? På vilka sätt skiljer respektive liknar de varandra samt vilka förutsättningar för parallellverkan kan urskiljas, dels generellt och dels specifikt i en ishockeykontext? Vilka tendenser och inslag kan skönjas i elitserien respektive SM-liiga av det faktum att ishockeyn genom åren både sportsligt och kommersiellt dominerats av NHL? Min studie visar att ishockeysporten är en spjutspets i amerikaniseringen och kommersialiseringen av nordisk sport samt att ishockeyns kommersialisering och professionalisering i någon form leder till en amerikanisering. Studien visar att företrädarna för den finska elitishockeyn haft stor autonomi präglat av förbundssplitting, vilket har sin förklaring i Finlands 1900-talshistoria. Denna självständighet har utgjort grund för den finska elitishockeyns snabba och häftiga utveckling efter andra världskriget. I jämförelse är Sverige präglat av konsensusorientering med Sveriges Riksidrottsförbund som centraladministration och paraplyorganisation för hela den svenska idrotten, även om Svenska Hockeyligan Ab på senare år fått allt större roll inom svensk ishockey. En slutsats är att Finlands högsta ishockeyserie kan anses vara en hybrid mellan den amerikanska respektive europeiska sportmodellen. Sveriges högsta ishockeyserie är å andra sidan närmare sammanlänkad med den europeiska sportmodellen, även om det finns stora kommersiella intressen inom svensk elitishockey.
13

Investigation of the Effects of Genistein and Fenretinide on Ovarian Cancer Cells

Azadi, Behnam 10 January 2012 (has links)
The effects of the fenretinide and genistein as single or combined drugs on ovarian cancer proliferation and viability were investigated. Hypothesis: Co-treatment with genistein will enable a lower dose of fenretinide to be effective in inhibiting the proliferation and survival of ovarian cancer cells. Methods: Low and high doses of genistein and fenretinide were tested on A2780s and A2780cp cells using trypan blue viable cell count, MTS assay. Results and conclusions: Unlike low doses of fenretinide, genistein had anti-proliferative effects on both cell lines. There were no additive or synergistic effects of the two compounds. Higher dose treatments induced anti-proliferative effects and apoptotic cell death in both A2780s and A2780cp cells, with a greater sensitivity of A2780s cells to both test compounds. Overall Conclusion: Genistein and higher doses of fenretinide similarly impair cell cycle progression and induce apoptosis. The anti-proliferative effects of genistein can be affected by co-treatment with fenretinide
14

Vliv podílu listnáčů ve SM monokulturách na diverzitu a druhové složení bylinného patra

Svobodová, Pavla January 2014 (has links)
This diploma thesis deals with the influence of hardwood species (particularly sessile oak -- Quercus petraea) in spruce monocultures on diversity and herb layer species composition. The aim of the thesis is create 40 phytosociological relevés with different percentage representation of aok in spruce monocultures. Particularly 10 relevés for 4 spruce monocultures variants was described: 10 relevés of 100 % spruce monocultures, 10 relevés of 90 % spruce monocultures with 10 % oak, 10 relevés of 80 % spruce monocultures with 20 % oak and up to 50 % of oak and 50 % of spruce. Resulting phytosociological data will be processed and floristic similarity of relevés will be evaluated based on species diversity indexes. The result draw conclusions about herbal layer abundance (quantitatively and qualitatively) in relation to portion of hardwood species in spruce monocultures.
15

Estudo Istópico dos Arenitos da Formação Ipú e Serrote Santana, noroeste do Ceará. / Istópico Study of the Sandstones of the Ipú and Serrote Santana Formation, northwest of Ceará.

Soares, Francisca Robenia Ferreira January 2017 (has links)
SOARES, Francisca Robênia Ferreira. Estudo Isotópico dos Arenitos da Formação Ipú e Serrote Santana, noroeste do Ceará. 2017. 133 f. Dissertação (Mestrado em Geologia)- Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by JOÃO CAVALCANTI JUNIOR (jbeniciojunior@yahoo.com.br) on 2017-06-19T16:00:03Z No. of bitstreams: 1 Dissertaçao Final.pdf: 41468471 bytes, checksum: 33c3cd2f9c3aa26a24f4477b323e19e8 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2017-07-11T18:19:09Z (GMT) No. of bitstreams: 1 Dissertaçao Final.pdf: 41468471 bytes, checksum: 33c3cd2f9c3aa26a24f4477b323e19e8 (MD5) / Made available in DSpace on 2017-07-11T18:19:09Z (GMT). No. of bitstreams: 1 Dissertaçao Final.pdf: 41468471 bytes, checksum: 33c3cd2f9c3aa26a24f4477b323e19e8 (MD5) Previous issue date: 2017 / The Ipú Formation composes the basal portion of the Serra Grande Group, Parnaíba Basin, and consists of sandstones and conglomerates deposited by interlaced fluvial systems during the Silurian. In the state of Ceará, these rocks appear in the Serra da Ibiapaba, presenting great expositions, forming hills and plateaus, on the northeast and east edges of the basin. The Morrote de Santana has an extension of approximately 30 km, is elongated in the NE-SW direction and consists of conglomeratic sandstones and sandstones. This silicystic sequence is aligned in the same direction as the rocks of the Ipú Formation. Although it is frequently correlated with the Ipú Formation, the rocks that make up the Morrote Santana are separated from the same in about 70 km, by expositions of epochal rocks (Jaibaras Group) and pre- Cambrian. In this context, the objective of the present study is to test the hypothesis that the Santana de Acaraú mound represents a testimonial hill of the Ipú Formation. The methodology used in the research involved geological reconnaissance techniques for the description of lithotypes and sample collection and Sm-Nd petrographic and isotopic analysis. The selected areas are located in the vicinity of Santana de Acaraú and Guaraciaba do Norte municipalities, north-west of Ceará, in the transition between the Middle Coreaú and Ceará Central Domains along the Sobral-Pedro II Line. These regions are bordered by rocks of the basement (Ceará Group) and lithotypes of the Jaibaras Basin, in addition to a siliciclastic sequence consisting of conglomerates, sandstone conglomerates, both with polymetallic characteristics, conglomerate sandstones with criss-cross and icnofossils, and medium sandstones Thick with ribbed cross laminations. The collected samples are representative of the more homogeneous portions of the sedimentary rocks recognized in the field, which were analyzed microscopically and isotopically, to determine their isotopic signatures. The petrographic study verified mature rocks and sub - sills, with a framework consisting of quartz grains and matrix occurring in a small amount (between 3-6%), of arenitic and sometimes clayey composition. These characteristics allow to classify these rocks as quatzo-sandstones. The isotopic signatures obtained showed little variation in the amounts of εNd (18.41 - 20.15) and TDM model ages varying between 3.21-2 Ga and 3.43-1.73 Ga, for the sediments present in the regions near Santana de Acaraú and Guaraciaba do North, respectively. The TDM ages indicate paleoproterozoic sources and archives for both areas and the low variation in εNd values reinforce the idea of the same source, evidencing evidence that the arenitic body of Santana de Acaraú represents a testimonial hill of the Ipú Formation. Key Words: Isotopic Geology, Sm-Nd Isotopes, Parnaíba Basin, Serrote Santana, Ipu Formation / A Formação Ipú compõe a porção basal do Grupo Serra Grande, Bacia do Parnaíba, e é constituída por arenitos e conglomerados depositados por sistemas fluviais entrelaçados, durante o Siluriano. No estado do Ceará, essas rochas afloram na Serra da Ibiapaba, apresentando grandes exposições, formando serras e chapadas, nas bordas nordeste e leste da bacia. O Morrote de Santana possui extensão de, aproximadamente, 30 km, encontra-se alongado na direção NE-SW e está constituído por arenitos e arenitos conglomeráticos. Essa sequência siliclástica encontra-se alinhada na mesma direção que as rochas da Formação Ipú, Apesar de ser frequentemente correlacionado a Formação Ipú, as rochas que compõe o Morrote Santana encontram-se separadas da mesma em cerca de 70 km, por exposições de rochas eopaleozóicas (Grupo Jaibaras) e pré-cambrianas. Dentro desse contexto, o objetivo do presente estudo consiste em testar a hipótese de que o morrote de Santana de Acaraú representa um morro testemunho da Formação Ipú. A metodologia utilizada na pesquisa, envolveu técnicas de reconhecimento geológico, para descrição dos litotipos e coleta de amostras e análise petrográfica e isotópica Sm-Nd. As áreas selecionadas localizam-se nas proximidades dos municípios de Santana de Acaraú e Guaraciaba do Norte, noroeste do Ceará, na transição entre os Domínios Médio Coreaú e Ceará Central, ao longo do Lineamento Sobral-Pedro II. Essas regiões encontram-se bordejadas por rochas do embasamento (Grupo Ceará) e litotipos da Bacia do Jaibaras, além de uma sequência siliciclástica constituída por conglomerados, conglomerados areníticos, ambos com características polimiticas, arenitos conglomerados com estratificação cruzada acanalada e icnofósseis e arenitos médios a grossos com estratificações cruzadas acanaladas. As amostras coletadas são representativas das porções mais homogêneas das rochas sedimentares reconhecidas em campo, as quais foram analisadas microscopicamente e isotopicamente, para determinação de suas assinaturas isotópicas. O estudo petrográfico constatou rochas maduras e submaduras, com arcabouço constituído por grãos de quartzo e matriz ocorrendo em pouca quantidade (entre 3-6 %), de composição arenítica e, por vezes, argilosa. Tais características permitem classificar essas rochas como quatzo-arenitos. As assinaturas isotópicas obtidas apresentaram pouca variação nas quantidades de εNd (18,41- 20,15) e idades modelo TDM variando entre 3.21 - 2 Ga e 3.43-1.73 Ga, para os sedimentos presentes nas regiões próximas a Santana de Acaraú e Guaraciaba do Norte, respectivamente. As idades TDM indicam fontes paleoproterozóicas e arquenas para ambas as áreas e a baixa variação nos valores de εNd, reforçam a ideia de mesma fonte, constatando indícios de que o corpo arenítico de Santana de Acaraú representa um morro testemunho da Formação Ipú. Palavras
16

Left-Right Symmetric Model : Putting lower bounds on the mass of the heavy, charged WR gauge boson

Harris, Melissa January 2017 (has links)
In this project I have studied the left-right symmetric model (LRSM) as a candidate beyond standard model theory of particle physics. The most common version of the theory, called the minimal LRSM, has been studied and tested extensively for several decades. I have therefore modied this minimal LRSM by adapting the scalar sector and computing the mass of the charged right-handed gauge bosons WR for this particular scalar sector. I carried out a study of the theory and implemented it into FeynRules, in order to simulate LHC events using MadGraph. This allowed computation of the cross-section for the decay WR to a top and a bottom quark as a function of the mass of WR , which was compared with CMS data for the same decay, with proton-proton collisions at a centre of mass energy of 13 TeV. The final result was a constraint on the mass of WR , with a lower bound of 3 TeV.
17

Investigation of the Effects of Genistein and Fenretinide on Ovarian Cancer Cells

Azadi, Behnam January 2012 (has links)
The effects of the fenretinide and genistein as single or combined drugs on ovarian cancer proliferation and viability were investigated. Hypothesis: Co-treatment with genistein will enable a lower dose of fenretinide to be effective in inhibiting the proliferation and survival of ovarian cancer cells. Methods: Low and high doses of genistein and fenretinide were tested on A2780s and A2780cp cells using trypan blue viable cell count, MTS assay. Results and conclusions: Unlike low doses of fenretinide, genistein had anti-proliferative effects on both cell lines. There were no additive or synergistic effects of the two compounds. Higher dose treatments induced anti-proliferative effects and apoptotic cell death in both A2780s and A2780cp cells, with a greater sensitivity of A2780s cells to both test compounds. Overall Conclusion: Genistein and higher doses of fenretinide similarly impair cell cycle progression and induce apoptosis. The anti-proliferative effects of genistein can be affected by co-treatment with fenretinide
18

Etude des étapes primaires de la dégradation thermique de la biomasse lignocellulosique / Primary stages study for lignocellulosic biomass thermal degradation

Khelfa, Anissa 06 July 2009 (has links)
La biomasse est une source d'énergie renouvelable qui capte et stock le CO2. Les objectifs de ce travail ont été d'étudier les comportements thermiques de la biomasse et de ses constituants (cellulose, hémicellulose et lignine). Nous nous sommes plus particulièrement intéressés aux mécanismes de dégradation thermique des polymères naturels survenant en premier dans les traitements thermiques(les mécanismes primaires). Ce travail a été réalisé dans le cadre de l'ACI "Biomasters" avec le soutien du crédit mutuel. Les comportements thermiques de différentes biomasses et de ses constituants ont été étudiés en utilisant la thermogravimétrie (ATG), la pyrolyse couplée à la spectrométrie de masse (Py-SM) et la pyrolyse couplée à la chromatographie gazeuse avec détection par spectrométrie de masse(Py-CG/SM). Nous avons montré, par ATG, que les comportements thermiques des constituants sont sensiblement différents et précisé leurs rôles dans la dégradation thermique. Nous avons aussi montré l'impossibilité de proposer des lois prévisionnelles du comportement thermique d'une biomasse sur la base des résultats obtenus pour ses constituants. En Py-SM nous avons développé une méthode permettant de mettre en évidence les fragments moléculaires les plus représentatifs de la dégradation thermique. Ceci nous a permis de préciser les constituants les plus sensibles à l'action de catalyseurs métalliques. L'analyse Py-CG/SM des mélanges a montré que les compositions des vapeurs dans les mélanges sont proches de lois d'addition simples. Nous terminons notre travail par une application de la pyrolyse / gazéification du Miscanthus pour la production d'un gaz à bonne valeur énergétique / Biomass is a renewable energy source, which collect and stock CO2. The objectives of this work were to study the thermal behavior of natural biomass and its components (cellulose, hemicellulose and lignin). We were particularly interested in the thermal degradation mechanisms of natural polymers arising, first, during heat treatments (primary mechanisms). This work was carried out with in the framework of the ACI "Biomasters" with the support of Credit Mutuel. The thermal behaviors of biomass and its components were studied by using thermogravimetry (TGA), pyrolysis coupled with mass spectrometry(Py-MS) and pyrolysis coupled with gas chromatography with detection by mass spectrometry (Py-GC/MS). The thermal behaviors of biomass components were shown, by TGA, to be appreciably different and their roles were specified in thermal degradation. We also showed the impossibility of proposing estimated laws of biomass thermalbehavior on the basis of the main component TGA results. With Py-MS, we developed a method allowing to highlight the most representative molecular fragments evolved during biomass thermal degradation. This enabled us to specify the most sensitive components towards metallic catalystaction. The Py-CG/SM analysis of the mixtures showed that vapor compositions in the mixtures are close to simple laws of addition. We complete our work by an application of pyrolysis/gasification of Miscanthus for the of a sas with value
19

Microstructural and tectonic applications of texturally-controlled Sm/Nd garnet geochronology

Stewart, Emily Mavis 09 November 2015 (has links)
High precision 147Sm-143Nd geochronology of garnet is performed in two localities to solve problems in tectonics. In Chapter 1, the age of the basal amphibolite unit of the Ballantrae Ophiolite complex in Scotland is dated at 477.6 ± 1.9 million years old. This age constrains the duration of Grampian orogenesis to 12.6 ± 3.1 million years and allows us to conclude that classic metamorphism by overthickening of continental crust cannot account for the very short-lived event in this region. In Chapter 2, we report ages from a Variscan relict (318 ± 130 Ma) to a range of Cenozoic ages from 35.5 ± 2.1 Ma to 9 ± 10 Ma in the Betic Cordillera of southern Spain. This alone indicates prolonged orogenesis in the region. These ages are linked directly to a microstructure known as a Foliation Intersection Axis (FIA). Results are inconclusive, but they generally indicate that there may be a relationship between broad scale plate motion and FIA orientations at a regional scale.
20

Géochimie et traceur isotopique du ND dans les intrusifs archéens de la partie Nord-Est de la Péninsule d'Ungava

Harvey, Dany January 1995 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

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