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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

Prematuridade como fator de risco no desenvolvimento motor e congnitivo avaliados com 1 e 2 anos de idade

Oliver, Katia Aceti 16 June 2010 (has links)
Resumo: Introdução: O número crescente de prematuros que sobrevivem ao período neonatal, fez aumentar a demanda por pesquisas, principalmente quanto ao seu desenvolvimento. A maior parte das pesquisas envolve a população de extremo baixo peso e menores idades gestacionais. No entanto, a maior população de sobreviventes à prematuridade é composta por prematuros tardios, de baixo risco e maior peso. Pesquisas que verifiquem os fatores que possam promover ou dificultar o desenvolvimento destas crianças parecem constituir uma lacuna a ser preenchida. Objetivos: Avaliar o desenvolvimento europsicomotor de prematuros nos dois primeiros anos de idade gestacional corrigida com a finalidade de verificar se a prematuridade por si só, assim como, verificar a importância dos fatores de risco obstétricos, socioeconômicos, ambientais e neonatais para o desenvolvimento neuropsicomotor. Material e Métodos: Trata-se de um estudo observacional, longitudinal e prospectivo, com seleção por conveniência. Os pacientes prematuros egressos de Unidades de Terapia Intensiva de Curitiba e Região Metropolitana foram comparados com grupo de crianças nascidas a termo e avaliadas pelo Teste de Triagem de Denver II com um e dois anos de idade corrigida para os prematuros e idade cronológica para os nascidos a termo. As crianças foram classificadas quanto aos fatores de risco obstétricos, neonatais, socioeconômicos e ambientais. Resultados: Foram estudados 201 pacientes, sendo 106 recém nascidos a termo e 95 prematuros. Dentre os testes alterados, no primeiro ano de vida, 44,7% eram de recém-nascidos a termo e 55,3% de recém-nascidos prematuros, e no segundo 46,9% de recém-nascidos a termo e 53,1% de recémnascidos prematuros. No primeiro ano, os pacientes do sexo masculino e aqueles com famílias mais numerosas (com quatro ou mais integrantes), apresentaram pior desempenho no Teste de Denver II. Quando o pai estava presente compondo a família do lactente houve melhores resultados no teste com significância limítrofe. As crianças cujas mães apresentavam escolaridade de nível superior apresentaram melhores resultados no Teste de Denver II, assim como com aquelas que eram cuidadas pelas mães em comparação às cuidadas por creches. Conclusões: Verificou-se que o desenvolvimento infantil depende de múltiplos fatores para a completa exteriorização do potencial genético. A prematuridade por si só não se mostrou um fator de risco para o desenvolvimento infantil nos dois primeiros anos de vida. Os fatores ambientais foram de maior importância quando o dano biológico não foi significativo no período neonatal e perinatal.
42

Tensores polares atomicos e energias das camadas internas

Oliveira, Anselmo Elcana de 25 July 2018 (has links)
Orientador: Roy Edward Bruns / Tese (doutorado) - Univerdade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-07-25T06:37:51Z (GMT). No. of bitstreams: 1 Oliveira_AnselmoElcanade_D.pdf: 3107411 bytes, checksum: 6192e522ac38fa972f36a1cc68e370ea (MD5) Previous issue date: 1999 / Doutorado
43

X-ray diffraction in liquids

Danielson, Gordon Charles January 1935 (has links)
[No abstract available] / Science, Faculty of / Physics and Astronomy, Department of / Graduate
44

An x-ray dose comparator

Mibus, Sidney Albert January 1956 (has links)
This thesis describes the design and construction of an instrument for comparison of x-ray doses at two different points in an x-ray field. Essentially, it consists of two ionization chambers each fed into a very stable, linear, d.c. amplifier. The outputs of the d.c. amplifiers are coupled in such a way that a fraction of the output of one amplifier is balanced against the total output of the other in a ratio circuit. The scale of the ratio circuit may be set to read directly the dose at any point as a percentage of the dose at an arbitrarily chosen reference point. This percentage is independent of fluctuations of the x-ray intensity with time. The instrument is battery-operated, light in weight and therefore easily portable. The principal use of the instrument is for the comparison of x-ray doses at different points in a tissue-equivalent medium — information required for dose estimates in radiotherapy. The accuracy of the instrument is better than one half percent of the maximum dose in the x-ray field. The instrument can be modified for automatic plotting of "isodose curves". / Science, Faculty of / Physics and Astronomy, Department of / Graduate
45

X-RAY EMISSION FROM LASER-HEATED SPHERICAL PLASMAS.

MOSTACCI, DOMIZIANO VALERIO. January 1985 (has links)
A model has been developed for calculating x-ray line emission from spherical plasmas. The main features of this method are: (1) Plasma parameters are obtained from a one-dimensional Lagrangian hydrodynamics and heat flow code. (2) Multi-frequency groups: the line structure can be reproduced with the desired accuracy by adjusting the number of frequency groups. (3) Self consistent, time dependent excited level populations and radiation fluxes: the code starts with coronal populations, calculates the ensuing radiation flux and then recalculates the populations and so on, iterating until convergence is reached. (4) Goemetrical groups of rays groups by spherical impact parameters. (5) Line broadening due to ionic thermal agitation and Doppler shift due to the net plasma flow velocity. Inclusion of the flow velocity shift would be different without the multi-frequency group treatment. The method has been applied to an aluminum target, and the results are in good agreement with previous experimental work. The total energy, summed over all lines, as well as the line intensity ratios (which are a sensitive measure of agreement with experiment) were predicted with good accuracy. The pictures that would be seen by a pinhole camera are also calculated by the code.
46

A map of diffuse low energy x-rays from the general direction of the galactic anti-center

Williamson, Fred Othar, January 1974 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1974. / Typescript. Vita. Includes bibliographical references.
47

Determinação da orientação relativa de blocos mosaicos pelo método do feixe de raios-X divergentes

Soledade Junior, Teomar 15 July 1976 (has links)
Orientador: Stephenson Caticha Ellis / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-17T03:49:17Z (GMT). No. of bitstreams: 1 SoledadeJunior_Teomar_M.pdf: 1604911 bytes, checksum: 19a40f8e895db33c918ab2914e1430a5 (MD5) Previous issue date: 1976 / Resumo: Não informado / Abstract: Not informed. / Mestrado / Física / Mestre em Física
48

When attitudes become words. Prácticas artísticas y nuevas espacialidades, en los límites de lo Común

Toboso Galindo, Juan Luis 12 November 2015 (has links)
[EN] This doctoral thesis opens to a theoretical and practical journey envisioning the importance of urban space as a social space, and its relation to contemporary artistic practices. The main aims of this research are those of analyzing, relating and reflecting multiple attitudes regarding the discussion on the dematerialization of the material object, and, the blurring of borders between artist and spectator, offering a series of proposals able to tension the role of the different agents implicated in the creative process. The relation of those ideas reads the event and verbal forms as singular artistic practices based on a dialectic practice as immaterial form and simultaneously as element of a new spatiality within the limits of the common. / [ES] El propósito de esta tesis doctoral es el de invitarles a hacer un viaje, a través de un recorrido teórico- práctico, donde nos proponemos investigar la importancia dEl Espacio urbano como espacio social y su vinculación a las prácticas artísticas en los últimos años. Con la premisa de analizar, discutir y relacionar diversas actitudes que basan su pensamiento en una desmaterialización del objeto y en la necesidad de difuminar las fronteras entre el artista y el espectador, vamos al encuentro de una serie de propuestas donde la tensión entre los diversos agentes implicados en el proceso creativo, se revela como el principal interés de esta investigación. Esta relación de ideas nos lleva a buscar en el acontecimiento y en las formas verbales, una práctica artística singular basada en la dialéctica como forma inmaterial y al mismo tiempo como elemento de una nueva espacialidad en los límites de lo Común. / [CA] El propòsit d'esta tesi doctoral és d'invitar-los a fer un viatge, a través d'un recorregut teòric- pràctic, on ens proposem investigar la importància de l'espai urbà, com a espai social i la seua vinculació a les pràctiques artístiques en els últims anys. Amb la premissa d'analitzar, discutir i relacionar diverses actituds que basen el seu pensament en una desmaterialització de l'objecte material i en la necessitat de difuminar les fronteres entre l'artista i l'espectador anem a la trobada d'una sèrie de propostes on la tensió entre els diversos agents implicats en el procés, es revela com el principal interés d'esta investigació. Esta relació d'idees ens porta a buscar en l'esdeveniment i en les formes verbals, una pràctica artística singular basada en la pràctica de la dialèctica com a forma immaterial i al mateix temps com a element d'una nova espacialitat en els límits del comú. / Toboso Galindo, JL. (2015). When attitudes become words. Prácticas artísticas y nuevas espacialidades, en los límites de lo Común [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/57367
49

Obtenção de espumas sintaticas da liga AA2011 a partir do metal no estado semi-solido e sua caracterização metalurgica / Manufacture of syntactic foams of the alloy AA2011 from the metal in the semi-solid state and metallurgical characterization of the product

Gatamorta, Fabio, 1973- 08 November 2018 (has links)
Orientador: Maria Helena Robert / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-11-08T18:33:56Z (GMT). No. of bitstreams: 1 Gatamorta_Fabio_M.pdf: 4781935 bytes, checksum: 65f15f84c18d74da8cad546219a2f994 (MD5) Previous issue date: 2009 / Resumo: O trabalho apresenta o desenvolvimento de processo de obtencao de espumas sintaticas da liga de aluminio AA2011 a partir da sua infiltracao, no estado semi-solido tixotropico, em preformas porosas de microesferas ocas de vidro sinterizadas. E analisada a influencia de parâmetros de processo na qualidade final do produto. Os parametros de processo variados foram: a temperatura para a infiltracao e o estado inicial da estrutura da liga metalica (extrudada e extrudada com adicional deformacao a frio de 80%), objetivando a variacao da fracao liquida (Fl = 0,6 e 0,8) e das dimensoes dos globulos solidos na pasta tixotropica, respectivamente. O material celular obtido foi analisado quanto a qualidade interna, via tomografia de raios-X; a microestrutura das paredes metalicas, por microscopia optica; foi caracterizado quanto a densidade aparente; e testado quanto a resistencia a compressao e ao impacto. Os resultados obtidos mostraram a possibilidade de obtencao de espumas sintaticas com homogeneidade arquitetural em todo seu volume. A qualidade do produto obtido e dependente das dimensoes das particulas do constituinte solido da pasta tixotropica - dimensoes elevadas, resultantes de processo de obtencao de pastas a partir de estruturas nao deformadas, podem nao permitir a infiltracao nas condicoes testadas; e da fracao liquida presente na pasta - baixas frações dificultam ou mesmo inviabilizam a infiltracao. Espumas de boa qualidade foram obtidas para as condicoes: infiltracao de pasta contendo globulos solidos refinados e temperatura de infiltração de 628ºC. A selecao incorreta de parametros de processo pode resultar em produtos com distribuicao heterogenea de poros ou ruptura da pre-forma. O produto obtido apresentou densidade relativa a liga macica, da ordem de 0,6, caracterizando uma espuma sintatica tipica. Resultados de compressao estatica e dinamica mostraram caracteristico plato de deformação plastica a baixas tensoes, tambem comportamento tipico de materiais celulares / Abstract: The work deals with the development of a process to produce syntactic foams of the AA2011 alloy by infiltration in the thixotropic semi-solid condition, into porous pre-forms of sintered hollow microspheres of glass. It is analyzed the influence of processing parameters in the quality of obtained product. Processing parameters investigated are the infiltration temperature and initial condition of the alloy (extruded and extruded plus additional cold deformation), aiming to observe the influence of liquid fraction (Fl = 0,6 and 0,8) and size of globular solid particles in the thixotropic slurry, respectively, in the infiltration ability. The cellular material produced was tested by X-ray tomography to analyze internal quality; metallic walls of cells were observed by optical microscopy; the material was also characterized in terms of apparent density and mechanical behavior in compression and impact tests. Results showed the viability of producing syntactic foams by the proposed process, with architectural homogeneity throughout the volume. Quality of product is dependent on size of the solid particles in the semi-solid metal and the infiltration temperature. High dimensions of globules, usually resulted from partial melting of non deformed structures, and low liquid fractions in the thixotropic semi-solid can lead to insufficient infiltration. Syntactic foams with reliable quality can be obtained in the system investigated, if the following conditions are used: fine globules and infiltration temperature of 628°C. Incorrect selection of processing parameters can lead to rupture of perform or products with heterogeneous distribution of porous. Obtained products presented relative density of 0,6, related to the massive alloy, characteristic of typical syntactic foams. Results of compression and impact tests showed the presence of plastic deformation plateau at low stress, also typical of cellular materials / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica
50

Comparison of Two X-ray Detection Systems Used to Investigate Properties of Normal and Malignant Breast Tissues

Alaroui, Duaa 06 1900 (has links)
The present study was implemented using two different X-ray detection systems; a monochromatic X-ray system for X-ray Fluorescence (XRF) and Angular Dispersive X-ray Diffraction (ADXRD) techniques, and a combined Polarized Energy Dispersive X-ray Fluorescence (PEDXRF) and Energy Dispersive X-ray Diffraction (EDXRD) system. As both of these systems involve different techniques, the primary objective of this study was to evaluate the performance and accuracy of each system using results achieved from XRF measurements. The assessment of the two systems was carried out by investigating invasive ductal carcinoma (IDC) of breast and normal surrounding breast tissues. The results established from the two XRF systems are in a very good agreement with each other. The statistical analysis reveals a significant and measurable increase at P<0.01 in the concentration of K, Ca, Zn, Rb and Fe (P<0.05) in the tumor tissue when compared with the healthy tissue. However, the levels of Cl, Cu and Br attained by both systems have not demonstrated a statistically significant difference between the normal and cancerous tissues. Investigating the structural components of the same breast tissues using of the X-ray Diffraction (XRD) spectrometers incorporated in both systems indicated a statistically significant difference in the components of normal and malignant samples. Furthermore, the results have shown a remarkable increase in the fibrous and water contents of the tumour tissue at P<0.01, and a significant increase in the adipose content of the normal tissue at P<0.01. The results acquired from both XRD approaches were shown to be statistically compatible with each other. Overall, the comparisons between the two X-ray detection systems have shown tremendous results for the combined PEDXRF and EDXRD system for the purpose of classifying normal and tumor breast tissues. / Thesis / Master of Science (MSc)

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