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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.
131

Modelo estocástico para estimação da produtividade de soja no Estado de São Paulo utilizando simulação normal bivariada / Sthocastic model to estimate the soybean productivity in the State of São Paulo through bivaried normal simulation

Thomas Newton Martin 08 February 2007 (has links)
A disponibilidade de recursos, tanto de ordem financeira quanto de mão-de-obra, é escassa. Sendo assim, deve-se incentivar o planejamento regional que minimize a utilização de recursos. A previsão de safra por intermédio de técnicas de modelagem deve ser realizada anteriormente com base nas características regionais, indicando assim as diretrizes básicas da pesquisa, bem como o planejamento regional. Dessa forma, os objetivos deste trabalho são: (i) caracterizar as variáveis do clima por intermédio de diferentes distribuições de probabilidade; (ii) verificar a homogeneidade espacial e temporal para as variáveis do clima; (iii) utilizar a distribuição normal bivariada para simular parâmetros utilizados na estimação de produtividade da cultura de soja; e (iv) propor um modelo para estimar a ordem de magnitude da produtividade potencial (dependente da interação genótipo, temperatura, radiação fotossinteticamente ativa e fotoperíodo) e da produtividade deplecionada (dependente da podutividade potencial, da chuva e do armazenamento de água no solo) de grãos de soja, baseados nos valores diários de temperatura, insolação e chuva, para o estado de São Paulo. As variáveis utilizadas neste estudo foram: temperatura média, insolação, radiação solar fotossinteticamente ativa e precipitação pluvial, em escala diária, obtidas em 27 estações localizadas no Estado de São Paulo e seis estações localizadas em Estados vizinhos. Primeiramente, verificou-se a aderência das variáveis a cinco distribuições de probabilidade (normal, log-normal, exponencial, gama e weibull), por intermédio do teste de Kolmogorov-Smirnov. Verificou-se a homogeneidade espacial e temporal dos dados por intermédio da análise de agrupamento pelo método de Ward e estimou-se o tamanho de amostra (número de anos) para as variáveis. A geração de números aleatórios foi realizada por intermédio do método Monte Carlo. A simulação dos dados de radiação fotossinteticamente ativa e temperatura foram realizadas por intermédio de três casos (i) distribuição triangular assimétrica (ii) distribuição normal truncada a 1,96 desvio padrão da média e (iii) distribuição normal bivariada. Os dados simulados foram avaliados por intermédio do teste de homogeneidade de variância de Bartlett e do teste F, teste t, índice de concordância de Willmott, coeficiente angular da reta, o índice de desempenho de Camargo (C) e aderência à distribuição normal (univariada). O modelo utilizado para calcular a produtividade potencial da cultura de soja foi desenvolvido com base no modelo de De Wit, incluindo contribuições de Van Heenst, Driessen, Konijn, de Vries, dentre outros. O cálculo da produtividade deplecionada foi dependente da evapotranspiração potencial, da cultura e real e coeficiente de sensibilidade a deficiência hídrica. Os dados de precipitação pluvial foram amostrados por intermédio da distribuição normal. Sendo assim, a produção diária de carboidrato foi deplecionada em função do estresse hídrico e número de horas diárias de insolação. A interpolação dos dados, de modo a englobar todo o Estado de São Paulo, foi realizada por intermédio do método da Krigagem. Foi verificado que a maior parte das variáveis segue a distribuição normal de probabilidade. Além disso, as variáveis apresentam variabilidade espacial e temporal e o número de anos necessários (tamanho de amostra) para cada uma delas é bastante variável. A simulação utilizando a distribuição normal bivariada é a mais apropriada por representar melhor as variáveis do clima. E o modelo de estimação das produtividades potencial e deplecionada para a cultura de soja produz resultados coerentes com outros resultados obtidos na literatura. / The availability of resources, as much of financial order and human labor, is scarse. Therefore, it must stimulates the regional planning that minimizes the use of resources. Then, the forecast of harvests through modelling techniques must previously on the basis of be carried through the regional characteristics, thus indicating the routes of the research, as well as the regional planning. Then, the aims of this work are: (i) to characterize the climatic variables through different probability distributions; (ii) to verify the spatial and temporal homogeneity of the climatic variables; (iii) to verify the bivaried normal distribution to simulate parameters used to estimate soybean crop productivity; (iv) to propose a model of estimating the magnitud order of soybean crop potential productivity (it depends on the genotype, air temperature, photosynthetic active radiation; and photoperiod) and the depleted soybean crop productivity (it pedends on the potential productivity, rainfall and soil watter availability) based on daily values of temperature, insolation and rain, for the State of São Paulo. The variable used in this study had been the minimum, maximum and average air temperature, insolation, solar radiation, fotosynthetic active radiation and pluvial precipitation, in daily scale, gotten in 27 stations located in the State of São Paulo and six stations located in neighboring States. First, it was verified tack of seven variables in five probability distributions (normal, log-normal, exponential, gamma and weibull), through of Kolmogorov-Smirnov. The spatial and temporal verified through the analysis of grouping by Ward method and estimating the sample size (number of years) for the variable. The generation of random numbers was carried through the Monte Carlo Method. The simulation of the data of photosyntetic active radiation and temperature had been carried through three cases: (i) nonsymetric triangular distribution (ii) normal distribution truncated at 1.96 shunting line standard of the average and (iii) bivaried normal distribution. The simulated data had been evaluated through the test of homogeneity of variance of Bartlett and the F test, t test, agreement index of Willmott, angular coefficient of the straight line, the index of performance index of Camargo (C) and tack the normal distribution (univarieted). The proposed model to simulate the potential productivity of soybean crop was based on the de Wit concepts, including Van Heenst, Driessen, Konijn, Vries, and others researchers. The computation of the depleted productivity was dependent of the potential, crop and real evapotranspirations and the sensitivity hydric deficiency coefficient. The insolation and pluvial precipitation data had been showed through the normal distribution. Being thus, the daily production of carbohydrate was depleted as function of hydric stress and insolation. The interpolation of the data, in order to consider the whole State of Sao Paulo, was carried through the Kriging method. The results were gotten that most of the variable can follow the normal distribution. Moreover, the variable presents spatial and temporal variability and the number of necessary years (sample size) for each one of them is sufficiently changeable. The simulation using the bivaried normal distribution is most appropriate for better representation of climate variable. The model of estimating potential and depleted soybean crop productivities produces coherent values with the literature results.
132

Análise harmônica dos totais de chuvas mensais de regiões homogêneas do Estado do Rio Grande do Sul / Harmonic analysis of the total rainfall monthly of homogeneous regions of the state of Rio Grande do Sul

Cardoso, Daniel Souza, Cardoso, Daniel Souza 24 March 2010 (has links)
Made available in DSpace on 2014-08-20T14:25:50Z (GMT). No. of bitstreams: 1 dissertacao_daniel_souza_cardoso.pdf: 4876863 bytes, checksum: f5480536e10753263d2ac710e5a3c660 (MD5) Previous issue date: 2010-03-24 / Whereas the State of Rio Grande do Sul (RS), have an economy directly dependent on agriculture and livestock sectors, which in different studies are reported as dependent on the variability of certain climatological elements, and the RS element water is regarded as fundamental. We conducted a study of the monthly total rainfall, to long 60 years (1948/2007), collected from 31 meteorological stations (EMs) and distributed geographically in the state. In the interest of contributing to the local society to predict possible shortages, and / or development of public policies for the use of water resources in urban and rural areas. In order to obtain a model that can provide an approximation of the behavior of the average rainfall for each of the six homogeneous regions, as defined in the literature (Marques, 2005), held has an harmonic analysis of the data previously adjusted to 30-day months. Before the analisys, the properties were checked for normality, homogeneity of variance and stationarity. The data tested for normality and homogeneity of variances, have not passed satisfactory in these tests and, hence, there was a transformation of data, generating new data sets that met the conditions of homogeneity of variance and normality. The relative increase in the trend, to long 60 years, ranged from 2,7 to 13,3% in the six homogeneous regions. Through harmonic analysis was obtained models that adequately represent the behavior of the average rainfall for the six homogeneous regions of RS, consisting of 3 or 4 sine waves, with one representation from 81 to 95% of the variability of the data. It was possible to found that some harmonics stood out, by have higher representation of the variability of the observed data, and the harmonic half stood out, in 50% of the models, and the harmonics quarterly and annual stood out, in 33,33% and 16,66% of, respectively. The models were tested to forecast, within the interval of 2003/2007, evolving in time according to the trend of time series of each region, being validated in residual analysis, by of residuals autocorrelation . Showing up as appropriate for forecast of future values. / Considerando que o Estado do Rio Grande do Sul (RS), possui uma economia diretamente dependente dos setores pecuário e agrícola, que em diferentes estudos são apontados como dependentes da variabilidade de alguns elementos climatológicos, e que no RS o elemento hídrico é considerado como fundamental. Realizou-se um estudo dos totais mensais de chuva ao longo de 60 anos (1948/2007), coletados de 31 estações meteorológicas (EMs) bem distribuídas, geograficamente, no Estado. Com o interesse de contribuir para a sociedade local, na previsão de possíveis racionamentos, e/ou na elaboração de políticas públicas para o uso dos recursos hídricos, nas áreas urbana e rural. Com o objetivo de obter um modelo, que possa apresentar uma aproximação do comportamento da precipitação pluvial média de cada uma das seis regiões homogêneas, já definidas na literatura (Marques, 2005), realizou-se uma análise harmônica dos dados previamente ajustados à meses de 30 dias. Antes da análise foram verificadas as propriedades de normalidade, homogeneidade de variâncias e estacionariedade. Os dados submetidos aos testes de normalidade, e de homogeneidade de variâncias, não obtiveram aprovação satisfatória nestes testes e, daí, realizou-se uma transformação de dados, gerando novos conjuntos de dados, que satisfizeram as condições de homogeneidade de variâncias e normalidade. O aumento relativo da tendência ao longo de 60 anos, variou de 2,7 a 13,3% nas seis regiões homogêneas. Através da análise harmônica obteve-se modelos que representam adequadamente o comportamento da precipitação pluvial média para as seis regiões homogêneas do RS, constituídos por 3 ou 4 ondas senoidais, apresentando uma representatividade de 81 a 95% da variabilidade dos dados. Foi possível constatar que alguns harmônicos destacaram-se por apresentar maior representatividade da variabilidade dos dados observados, sendo que o harmônico semestral destacou-se em 50% dos modelos, e que os harmônicos quadrimestral e anual destacaram-se em 33,33% e 16,66% destes, respectivamente. Os modelos foram testados para previsão, compreendida no intervalo de 2003/2007, evoluindo no tempo de acordo com a tendência das séries temporais de cada região, sendo validados na análise residual pela autocorrelação dos resíduos. Mostrando-se como adequados para previsão de valores futuros.
133

Patrick Bateman, Violence and Consumption: Bret Easton Ellis’s American Psycho

Nystrand, Alexander January 2010 (has links)
This essay investigates how Bret Easton Ellis portrays Patrick Bateman as a projection of American society, in order to criticize consumerism and capitalism in his novel American Psycho. By applying Marxist theory, this essay examines Bateman's consumption patterns and class-consciousness using key Marxist terms. This essay investigates the relationship between Bateman and his commodities, through the Marxist concept of value. Furthermore, this essay suggests that Bateman's consumption pattern creates his identity and that Bateman's lust for consumption has no boundaries. Bateman quenches his thirst for consumption by consuming humans of low status on the social hierarchy, by acts of violence, rape or cannibalism.
134

DINÂMICA DO CARBONO- 13C DE RAÍZES E RESÍDUOS DE PARTE AÉREA DE CULTURAS DE VERÃO EM DOIS SOLOS DE VÁRZEA / 13C-CARBON DYNAMICS OF ROOTS AND SHOOTS FROM SUMMER CROPS IN TWO LOWLAND SOILS

Dossin, Mariana Ferneda 10 March 2016 (has links)
The use of isotopic techniques has been widely used in studies related to changes in the soil C. The chemical quality of crop residues and the type of management used are considered to be the main factors that control the dynamics of soil C. However, the stabilization of C derived from crop residues is also dependent on soil texture. Therefore, the objectives of these studies were: a) to evaluate the efficiency of repeat pulse labeling technique for the isotopic enrichment of leaves, stems and roots of rice, sorghum and soybeans plants with 13C under greenhouse conditions and b) to evaluate the dynamics of C during the decomposition of 13C enriched shoots and roots of rice, sorghum and soybean plants in two lowland soils with different texture. The studies were conducted in the greenhouse of the department of soils, Federal University of Santa Maria (UFSM), Brazil. In the first study, rice, sorghum and soybeans plants were exposed weekly to isotopic pulses with 33% 13CO2 atoms, for 1-1,5h in closed acrylic chambers till grain filling stage. Delta 13C enrichment, chemical composition and the recovery and distribution of 13C in plant parts and soil was determined. In the second study, enriched residues obtained in the first study were used to study the dynamics of C in two lowland soils The soils were Planossolo Hidromórfico Eutrófico gleissólico and Planossolo Hidromórfico Eutrófico arênico. The experimental design was completely randomized with three replications with 18 treatments, which were composed of a combination of 13C enriched shoots and roots with non-enriched shoots and roots (natural abundance). The soil was collected after 30, 90 and 180 days and the amounts of 13C remaining in residues and soil and the new C in soil was determined. The dry matter (DM) production and chemical composition of the residues was not affected by the 13C enrichment. The enrichment values were +377 for rice, + 466.5 for sorghum and + 453.7 for soybean. The isotopic enrichment of plants with 13C by repeated pulses was efficient for the homogeneous enrichment of rice, sorghum and soybean plants in greenhouse conditions. Regarding the dynamics of the soil C, the management of rice residues affected the decomposition and the addition of new C in the soil. The quality of the residues influenced the decomposition process. There was no difference in the decomposition of the roots of the three crop plants. The type of the soil did not affect the decomposition of shoot and root, residues of soybean, sorghum and rice plants. The amount of new C was influenced by the type of residues and soil. The roots contributed greater amounts of C in the soil in relation to the shoots. / Resumo O uso de técnicas isotópicas tem sido amplamente utilizado em estudos relacionados a transformações do C no solo. A qualidade química dos resíduos culturais e o tipo de manejo utilizado são considerados os principais fatores que controlam a dinâmica do C no solo. Contudo a estabilização do C oriundo dos resíduos culturais é dependente da textura do solo. Os objetivos desses estudos foram: a) avaliar a eficiência do enriquecimento isotópico com 13C de folhas, talos e raízes das plantas de arroz, sorgo e soja cultivadas em solo de várzea em condições de casa de vegetação; b) avaliar a dinâmica do C durante a decomposição da parte aérea e de raízes de arroz, sorgo e soja enriquecidos isotopicamente com 13C em dois solos de várzea com textura distinta. Os estudos foram conduzidos em casa de vegetação na Universidade Federal de Santa Maria utilizando solos de várzea. No primeiro estudo, plantas de arroz, sorgo e soja foram expostas semanalmente aos pulsos isotópicos com 33% átomos de 13CO2, durante 1-1,5h, em câmaras fechadas de acrílico até o estádio de enchimento de grãos. Foram determinados os valores de enriquecimento com 13C dos órgãos das plantas, a composição química dos resíduos e valores de recuperação e distribuição do 13C nos órgãos da planta e no solo. No segundo estudo, foi realizada uma incubação com duração de 180 dias, com a utilização dos resíduos culturais enriquecidos no estudo I. Foram utilizados resíduos de parte aérea e raízes de arroz (Oryza sativa L.), sorgo (Sorghum bicolor L.) e soja (Glycine max L.) em dois solos de várzea, um Planossolo Hidromórfico Eutrófico gleissólico e um Planossolo Hidromórfico Eutrófico arênico. O delineamento utilizado foi o inteiramente casualizado com três repetições e 18 tratamentos, os quais foram compostos por uma combinação de palha enriquecida com 13C e com raízes também enriquecidas com 13C ou com raízes não enriquecidas (condição natural). Foram realizadas três datas de coleta aos 30, 90 e 180 dias nas quais foram avaliadas as quantidades de 13C remanescente nos resíduos e no solo, e o C novo no solo. A produção de MS e composição química dos resíduos não foi afetada pelo enriquecimento com 13C. Os valores de enriquecimento foram de +377 em arroz, +466,5 em sorgo e +453,7 em soja. O enriquecimento isotópico das plantas com 13C por meio de pulsos repetidos foi eficiente para o enriquecimento homogêneo de plantas de arroz, sorgo e soja em condições de casa de vegetação. Em relação a dinâmica do C no solo, o manejo dos resíduos de arroz afetou a decomposição e a adição de C novo no solo. Houve influência da qualidade dos resíduos sobre o processo de decomposição. Não houve diferença na decomposição das raízes das três culturas estudadas. O tipo de solo não afetou a decomposição da palha e raízes de soja, sorgo e arroz. A quantidade de C novo foi influenciada pelo tipo de resíduo e pelo solo. As raízes adicionam maior quantidade de C ao solo em relação à parte aérea.
135

Neuropsychological performance and functional MRI findings in children with non-lesional temporal lobe epilepsy

Mankinen, K. (Katariina) 04 February 2014 (has links)
Abstract The purpose of the present work was to investigate whether children with non-lesional temporal lobe epilepsy (TLE) have deficits in neuropsychological performance and whether the possible deficits can be investigated using functional magnetic resonance imaging (fMRI). In this population-based study, 21 children aged 8-15 with non-lesional TLE and a normal intelligence quotient were evaluated and compared with 21 healthy, age- and gender-matched controls. Neuropsychological assessments, clinical examinations, electroencephalography (EEG) and structural and functional MRI were performed on all the subjects. Three fMRI methods were used: resting-state regional homogeneity, resting-state functional connectivity and task-induced blood oxygenation level-dependent activation. The patients with non-lesional TLE showed good neuropsychological performance on average, although the girls were found to have significant problems in several neuropsychological tests. The deficits were not restricted to elements of performance involving the classical temporal lobe memory system but were also found in tests requiring frontal and parietal lobe functioning. Early onset of epilepsy and duration of epilepsy had significant negative effects on neuropsychological performance. All the fMRI methods detected significant functional differences between the TLE patients and the healthy controls, not only in the temporal lobes but also in broad networks extending to the frontal, parietal and thalamic areas. These differences seemed to differ markedly in location between the TLE patients depending on the interictal EEG findings. Neuropsychological performance results were supported by the fMRI findings, implying that TLE should be regarded as a widespread disruption of the brain networks and not just malfunction of a single region in the brain within these networks. This needs to be taken into consideration when evaluating learning abilities among TLE patients even at an early stage in epilepsy. / Tiivistelmä Tutkimuksen tarkoituksena oli selvittää onko lapsilla, jotka sairastavat tuntemattomasta syystä aiheutuvaa ohimolohkoepilepsiaa, neuropsykologisia ongelmia ja aiheuttavatko mahdolliset ongelmat aivojen toiminnallisessa magneettikuvauksessa nähtäviä muutoksia. Tähän väestöpohjaiseen tutkimukseen otettiin 21 tuntemattomasta syystä ohimolohkoepilepsiaa sairastavaa normaaliälyistä 8-15-vuotiaista lasta ja verrattiin heitä 21 terveeseen, ikä- ja sukupuolivakioituun kontrollihenkilöön. Kaikille tutkimukseen osallistuneille tehtiin neuropsykologinen tutkimus, kliininen tutkimus, aivosähkökäyrä sekä rakenteellinen ja toiminnallinen aivojen magneettikuvaus. Toiminnallisessa magneettikuvauksessa käytettiin veren happipitoisuudesta riippuvaista (engl. blood oxygenation level-dependent) kontrastia kuvantamaan levossa aivojen paikallista homogeniteettia (engl. regional homogeneity) ja toiminnallista kytkennällisyyttä (engl. functional connectivity) sekä kognitiivisten tehtävien herättämiä aktivaatio-vasteita. Tuntemattomasta syystä ohimolohkoepilepsiaa sairastavien lasten neuropsykologinen suoriutuminen oli keskimäärin hyvää, vaikkakin tytöillä oli nähtävillä tilastollisesti merkitseviä ongelmia useissa eri testeissä. Ongelmat eivät rajoittuneet pelkästään klassisiin ohimolohkoalueen muistitoimintoihin, vaan niitä havaittiin myös otsa- ja päälakilohkojen toimintoja edellyttävissä testeissä. Varhainen sairastumisikä ja epilepsian kesto heikensivät suoriutumista tilastollisesti merkitsevästi osatesteissä, joissa tarvittiin näönvaraisen hahmottamisen taitoja, psykomotorista nopeutta ja työmuistia. Ohimolohkoepilepsiaa sairastavien ja terveiden kontrollien aivoissa löydettiin toiminnallisia eroja kaikilla toiminnallisen magneettikuvauksen menetelmillä. Eroja ei todettu ainoastaan ohimolohkoissa, vaan niitä löytyi myös otsa- ja päälakilohkoon sekä tyvitumakealueelle ylettyvissä laaja-alaisissa hermoverkostoissa. Epilepsiapotilailla erojen paikantuminen riippui kohtaustenvälisestä aivosähkökäyrälöydöksestä. Neuropsykologisen suoriutumisen tulokset tukevat toiminnallisen magneettikuvauksen löydöksiä kuvastaen temporaaliepilepsian olevan laaja-alainen hermoverkostojen häiriö eikä pelkästään tietyn aivoalueen toiminnan häiriö. Tämä tulee huomioida arvioitaessa ohimolohkoepilepsiaa sairastavien lasten oppimiskykyä jo epilepsian alkuvaiheessa.
136

Análise do índice de conformidade e do índice de homogeneidade em planejamentos radioterápicos comparação entre as técnicas de IMRT, 3D-CRT. /

Arruda, Gabriel Augusto do Nascimento January 2020 (has links)
Orientador: Marco Antônio Rodrigues Fernandes / Resumo: Os modernos sistemas de planejamentos de tratamento (Treatment Planning System - TPS) computadorizados possibilitam a análise de parâmetros que informam sobre a homogeneidade (Índice de Homogeneidade - IH) e a conformidade (Índice de Conformidade - IC) da distribuição de dose de radiação em todo o volume irradiado. O IH é determinado verificando o gradiente de dose de radiação em todo o volume de tratamento planejado (PTV), uma distribuição de dose perfeitamente homogênea implica em IH igual a zero. O IC representa o grau de conformidade entre a região do PTV coberta pela dose prescrita e o volume total do PTV, quanto mais próximo do valor 1,0 melhor a conformidade do tratamento. Nesta pesquisa foram analisados os índices IH e IC para 82 casos clínicos de pacientes anteriormente submetidos à radioterapia, comparando os valores calculados destes parâmetros em planejamentos realizados com a técnica radioterápica tridimensional conformacional (3D-CRT) com a técnica de radioterapia de intensidade modulada (IMRT), e correlacionando estes índices com a dose de radiação preconizada em cada um dos casos clínicos estudados. Os planejamentos radioterápicos foram efetuados em dois diferentes Sistemas de Planejamento de Tratamento (TPS), o TPS Eclipse e o TPS XiO. Os resultados apontam que os planejamentos feitos com a técnica de IMRT apresentam valores de IC e IH levemente melhores do que os obtidos com a técnica 3D-CRT. / Abstract: Modern Treatment Planning System (TPS) computerized allows the analysis of parameters that report on the homogeneity index (HI) and conformity index (CI) of radiation dose distribution throughout the irradiated volume. IH is determined by checking the radiation dose gradient across the PTV (planned treatment volume), a perfectly homogeneous dose distribution implies IH = zero. The IC represents the degree of conformity between the PTV region covered by the prescribed dose and the total PTV volume, the closer to 1.0 the better the treatment compliance. In this research IH and IC indices were analyzed for 82 clinical cases previously submitted to radiotherapy, comparing the calculated values of these parameters in three-dimensional conformal radiation therapy (3D-CRT) planning with the intensity modulated radiation therapy (IMRT) technique, and correlating these indices with radiation dose recommended in each of the clinical cases studied. Radiotherapy planning was carried out in two different treatment planning system (TPS): TPS Eclipse and TPS XiO. The results indicated that the plans made with the IMRT technique present slightly better IC and IH values than those obtained by 3DCRT technique. / Mestre
137

L'univers aux grandes échelles : études de l'homogénéité cosmique et de l'énergie noire à partir des relevés de quasars BOSS et eBOSS / The universe on large scales : studies of cosmic homogeneity and dark energy with the BOSS et eBOSS quasar surveys

Laurent, Pierre 14 September 2016 (has links)
Ce travail de thèse se sépare en deux volets. Le premier volet concerne l'étude de l'homogénéité de l'univers, et le second une mesure de l'échelle BAO, qui constitue une règle standard permettant de mesurer l'évolution du taux d'expansion de l'univers. Ces deux analyses reposent sur l'étude de la structuration (ou clustering) des quasars des relevés BOSS et eBOSS, qui couvrent la gamme en redshift 0,9 < z < 2,8. Les mesures des observables caractérisant la structuration de l'univers aux grandes échelles sont très sensibles aux effets systématiques, nous avons donc étudiés ces effets en profondeur. Nous avons mis en évidence que les sélections de cibles quasars BOSS et eBOSS ne sont pas parfaitement homogènes, et corrigé cet effet. Au final, la mesure de la fonction de corrélation des quasars nous a permis de mesurer le biais des quasars sur la gamme en redshift 0,9 < z < 2,8. Nous obtenons la mesure actuelle la plus précise du biais, b = 3,85 ± 0,11 dans la gamme 2,2 < z < 2,8 pour le relevé BOSS, et b = 2,44 ± 0,04 dans la gamme 0,9 < z < 2,2 pour le relevé eBOSS. Le Principe Cosmologique stipule que notre univers est isotrope et homogène à grande échelle. Il s'agit d'un des postulats de base de la cosmologie moderne. En étudiant la structuration à très grande échelle des quasars, nous avons prouvé l'isotropie spatiale de l'univers dans la gamme 0,9 < z < 2,8, indépendamment de toute hypothèse et cosmologie fiducielle. L'isotropie spatiale stipule que l'univers est isotrope dans chaque couche de redshift. En la combinant au principe de Copernic, qui stipule que nous ne nous situons pas à une position particulière dans l'univers, permet de prouver que notre univers est homogène aux grandes échelles. Nous avons effectué une mesure de la dimension de corrélation fractale de l'univers, D₂(r), en utilisant un nouvel estimateur, inspiré de l'estimateur de Landy-Szalay pour la fonction de corrélation. En corrigeant notre estimateur du biais des quasars, nous avons mesuré (3 - D₂(r)) = (6,0 ± 2,1) x 10⁻⁵ entre 250 h⁻¹ Mpc et 1200 h⁻¹ Mpc pour le relevé eBOSS, dans la gamme 0,9 < z < 2,2. Pour le relevé BOSS, nous obtenons (3 - D₂(r)) = (3,9 ± 2,1) x 10⁻⁵, dans la gamme 2,2 < z < 2,8. De plus, nous montrons que le modèle Lambda-CDM décrit très bien la transition d'un régime structuré vers un régime homogène. D’autre part, nous avons mesuré la position du pic BAO dans les fonctions de corrélation des quasars BOSS et eBOSS, détecté à 2,5 sigma dans les deux relevés. Si nous mesurons le paramètre α, qui correspond au rapport entre la position du pic mesuré et la position prédite par une cosmologie fiducielle (en utilisant les paramètres Planck 2013), nous mesurons α = 1,074 pour le relevé BOSS, et α = 1,009 pour le relevé eBOSS. Ces mesures, combinées uniquement à la mesure locale de H₀, nous permettent de contraindre l'espace des paramètres de modèles au-delà du Lambda-CDM. / This work consists in two parts. The first one is a study of cosmic homogeneity, and the second one a measurement of the BAO scale, which provides a standard ruler that allows for a direct measurement of the expansion rate of the universe. These two analyses rely on the study of quasar clustering in the BOSS and eBOSS quasar samples, which cover the redshift range 0.9 < z < 2.8. On large scales, the measurement of statistical observables is very sensitive to systematic effects, so we deeply studied these effects. We found evidences that the target selections of BOSS and eBOSS quasars are not perfectly homogeneous, and we have corrected this effect. The measurement of the quasar correlation function provides the quasar bias in the redshift range 0.9 < z < 2.8. We obtain the most precise measurement of the quasar bias at high redshift, b = 3.85 ± 0.11, in the range 2.2 < z < 2.8 for the BOSS survey, and b = 2.44 ± 0.04 in the range 0.9 < z < 2.2 for the eBOSS survey. The Cosmological Principle states that the universe is homogeneous and isotropic on large scales. It is one of the basic assumptions of modern cosmology. By studying quasar clustering on large scales, we have proved ''spatial isotropy'', i.e. the fact that the universe is isotropic in each redshift bins. This has been done in the range 0.9 < z < 2.8 without any assumption or fiducial cosmology. If we combine spatial isotropy with the Copernican Principle, which states that we do not occupy a peculiar place in the universe, it is proved that the universe is homogeneous on large scales. We provide a measurement of the fractal correlation dimension of the universe, D₂(r), which is 3 for an homogeneous distribution, and we used a new estimator inspired from the Landy-Szalay estimator for the correlation function. If we correct our measurement for quasar bias, we obtain (3 - D₂(r)) = (6.0 ± 2.1) x 10⁻⁵ between 250 h⁻¹ Mpc and 1200 h⁻¹ Mpc for eBOSS, in the range 0.9 < z < 2.2. For BOSS, we obtain (3 - D₂(r)) = (3.9 ± 2.1) x 10⁻⁵, in the range 2.2 < z < 2.8. Moreover, we have shown that the Lambda-CDM model provide a very nice description of the transition from structures to homogeneity. We have also measured the position of the BAO peak in the BOSS and eBOSS quasar correlation functions, which yield a 2,5 sigma detection in both surveys. If we measure the α parameter, which corresponds to the ratio of the measured position of the peak to the predicted position in a fiducial cosmology (here Planck 2013), we measure α = 1.074 for BOSS, and α = 1.009 for eBOSS. These measurements, combined only with the local measurement of H₀, allows for constraints in parameter space for models beyond Lambda-CDM.
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Hodnocení kvality provedení ručně stříkaného betonu / Evaluating the quality of implementation of the hand shotcrete

Kopecký, Lukáš Unknown Date (has links)
Currently, the high speed and low price are required for construction works in the modern architecture. Therefore, it is necessary to deal with verifying the quality of the constructions. Dissertation thesis is focused on evaluating the quality of the execution of sprayed concrete without accelerating additives applied by spraying by a dry way manually-sprayed. The quality of shotcrete was judged on the basis of standardized both non-destructive and destructive methods using sprayed samples. The quality of shotcrete was assessed in terms of strength of sprayed concrete in pressure, density and homogeneity judged on the basis of the velocity of sound samples. The destructive method was carried out on the core samples which were pressured on the hydraulic press, as the non-destructive method was used ultrasonic passageway method based on the propagation velocity of the ultrasonic pulse. On the basis of our results and their mutual correlations, it has been proposed the modifications of the general equal used for predicting the strength of the sprayed concrete tested by our strength class, which leads to a potential reduction in the number of cores on the real structure, and therefore reduce the price of implementation of qualitative tests and increase effectiveness of carrying out tests on the construction place.
139

Návrh technologie a ověření výroby malých ocelových ingotů / Design of a technology and checking the production of small steel ingots

Jakubčíková, Lucie January 2019 (has links)
The thesis deals with the design of ingots from duplex (austenitic-ferritic) stainless steels in terms of minimal occurrence of axial porosity. The optimal shape and dimension of the ingot and the casting conditions are determined based on numerical simulations. The resulting internal quality of the realized ingot is evaluated. The presence of shrinkage porosity is determined by penetrant testing. The degree of chemical heterogeneity, the extent of macrosegregation, of selected elements in given ingot locations is measured by an optical emission spectrometer. Segregation values are compared with simulation results. The micro-purity of the ingot is assessed on the basis of metallographic samples.
140

Investigation of Intrinsic Brain Networks in Localization-related Epilepsy: A Resting-State fMRI Study

Ogen, Shatgul 24 May 2022 (has links)
No description available.

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