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Estudo do comportamento de HMS-SP (Polipropileno com alta resistencia do fundido) sob condicoes de degradacao ambiental e acelerada / Study of HMS-PP (high melt strength polypropylene) behaviour under conditions of environmental and accelerated degradationOLIANI, WASHINGTON L. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:55:39Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:00Z (GMT). No. of bitstreams: 0 / O estudo do comportamento de materiais poliméricos em relação ao intemperismo (calor, luz UV, umidade, radiação de alta energia, ataque químico e poluentes) é de fundamental importância para se avaliar a estabilidade do material. Os termoplásticos avaliados foram os HMS-PPs sintetizados, a partir do iPP estabilizado e não estabilizado, por meio de irradiação gama (g) em atmosfera de acetileno. A caracterização das amostras degradadas foi estabelecida por ensaios mecânicos, espectroscopia no infravermelho por transformada de Fourrier (FTIR), análise termogravimétrica (TGA), calorimetria exploratória diferencial (DSC), microscopia óptica (MO), microscopia eletrônica de varredura (MEV) e reometria de placas paralelas. O HMSPP, obtido a partir de esferas, nas condições de envelhecimento natural e acelerado sob radiação UV, evidencia a formação de cristais defeituosos que se organizam em diferentes estruturas. Na condição de termooxidação em estufa, apesar da cisão de cadeias, a fase cristalina diminui. O HMSPP 20 kGy parece ser mais estável às reações de cisão de cadeia nos testes que envolvem a radiação UV. A reologia indica que as ramificações com acetileno são mais estáveis à radiação ultravioleta. No HMSPP, obtido a partir de grãos, devido à eficiência dos aditivos como capturadores de espécies oxidadas e supressores de peróxido radicais, foram propiciadas mais as reações de cisão que a formação de cristais irregulares e isso conduziu ao aumento da cristalinidade tanto sob envelhecimento natural quanto térmico ou sob radiação ultravioleta (UV). As propriedades físicas sob tração mostraram que a diferença superior da tensão de ruptura inicial do HMS 20 kGy é perdida durante exposição a diversos envelhecimentos. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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\"Diferenciação entre rums cubanos e não cubanos\" / \"Differentiate between cuban rums and non-cuban rums\"Olívia Moreira Sampaio 24 November 2006 (has links)
Com o objetivo de definir a composição química do rum a e encontrar descritores que permitam distinguir rums cubanos de rums não cubanos, foram analisadas 44 amostras de rum provenientes de 15 países diferentes. Essas análises foram realizadas por GC-FID, HPLC-UV-Vis, AAS e ICP OES. Os resultados analíticos foram analisados utilizando quimiometria (PLS, PCA, QDA, LDA, HCA e FA), que permitiu determinar quais analitos apresentam características significativas para separação dos rums em duas classes: Cubanos e Não Cubanos. / With the aim to define the chemical profile of rum and achieve descriptors that allows the distinction among Cubean rums and non- Cubean rums, the analysis of 44 samples of rum from 15 differents countries were reported. To provide the chemical descriptors, the analysis of mineral composition (cupper, iron, zinc, magnesium, manganese, cadmium, lead, nickel, cobalto, chromium, calcium, barium, sodium, lithium, strontium), phenolic profile (gallic acid, syringic acid, miricetin, ellagic acid, syringaldehyd, vanillin, vanillic acid, epicatechin, catechin, scopoletin, coniferaldehyde, sinapaldehyde, trans-resveratrol, quercetin, eugenol, coumarin), caramel content, alcohols composition (methanol, propanol, isobutanol, 2-butanol, butanol, isoamyl alcohol), acetic acid content, ethyl acetate content, aldehydes (formaldehyde, butyraldehyde, furfuraldehyde, 5-hydroxymethylfurfural, acetaldehyde, crotonaldehyde, propionaldehyde, isobutyraldehyde, benzaldehyde, valeraldehyde, isovaleraldehyde, acrolein), and ketones (2,3-butanodiona monoxime, ciclopentanone, acetilcetone, acetophenone, acetone, metil-isoamil-ketone) were carried out. The experimental results were theatead through exploratory and classification chemometric methods (principal component analysis, hierarchical cluster analysis, partial least squares, factor analysis, linear and quadratic discriminant analysis), that allowed determination of analytes which shown significant characteristics to separation rums into two distinct groups. The chemometric results highlighted that from all the classes of compounds studied were identified descriptors, with alternated participating loadings, that are capables to distinguish the spirit and classify it a acording to their origin. The PCA analysis present in this separation, an acumulative percentage in the first three principal components of 70.4%, having isoamyl alcohol and furfural as significant descriptors for PC1. In the classification of the Cuban rum and non Cuban rum, the LDA model classified rums with 97.1% of accuracy using acetone, ethyl acetate, 2- butanol, 1-propanol, 1-butanol, isoamyl alcohol, caramel, barium, strontium, vanillic acid, vanillin, syringic acid, catechin, epicatechin, magnesium, acetaldehyde, ciclopentanonona, lead, isobutanol, zinc, calcium, sodium, and crotonaldehyde as descriptors, and with a inclusion of 10 blind samples to test the model, it was achived a percentage of correct assessment of 80% using those 23 chemical descriptors. These results suggested that the spirit, rum, show differences in its chemical composition related to mineral contents, aldehydes, ketones, alcohols, phenolic compounds, caramel, acetic acid and ethyl acetate, wich may be used to classify it according to the geographic origin.
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Integridade do ecossistema, avaliada a partir da dinâmica de temperatura de superfície e estoque de carbono no solo, na Bacia do Rio Corumbataí, SP / Ecosystem integrity, assessed by the surface temperature dynamics and soil organic carbon stock, in the Corumbataí River Basin, SPRodrigo de Almeida Muniz 22 October 2014 (has links)
Este trabalho objetivou pesquisar a relação da temperatura de superfície (LST) e do estoque de carbono no solo (ECS) com os diferentes tipos de uso e cobertura do solo (UCT). Sabe-se que tais parâmetros podem ser influenciados pelas atividades antrópicas, podendo afetar a integridade do agroecossistema (IAG) da bacia do Rio Corumbataí (BRC). Entende-se por IAG, a capacidade de manutenção de suas propriedades \"primitivas\" e prestação de serviços ecossistêmicos à sociedade. Para alcançar o objetivo proposto, a dinâmica de UCT foi mapeada, a partir da classificação de imagens do satélite Landsat e fotografias aéreas, dos anos de 1962 a 2011. A LST foi obtida por técnicas de sensoriamento remoto, utilizando a banda termal do sensor TM (Thematic Mapper) do Landsat, para os anos de 1985, 1990, 1995, 1999, 2002 e 2011. A análise do ECS foi feita a partir da coleta de amostras de solo, em diferentes UCT: mata nativa, cana-de-açúcar, pastagem e fruticultura, na profundidade de 0-10 e 10-20 cm. Os resultados indicaram que a LST e os ECS da área de estudo são influenciados pelo UCT e pelo manejo das culturas. Verificou-se ainda que algumas políticas agrícolas, adotadas no período de 1962 a 2011, influenciaram a dinâmica de UCT e, consequentemente, a capacidade do agroecossistema da BRC no fornecimento de serviços ecossistêmicos e também geraram custos ambientais. A abordagem interdisciplinar adotada neste trabalho, com o emprego das geotecnologias, mostrou ser capaz de avaliar a integridade do agroecossistema da BRC, podendo subsidiar o planejamento de uso do solo visando a maximizar a relação benefício/custo das atividades antrópicas, considerando a LST e o ECS. Tal abordagem pode ser aplicada em diferentes áreas do conhecimento para a análise da sustentabilidade e integridade ambiental dos agroecossistemas. / In this work, the aim was search the relationship between both surface temperature (LST) and soil organic carbon (SOC) with several sort of land use cover (LUC). We know such a parameters can be influenced by anthropic activities, it can affects the Corumbataí River basin (CRB) agro ecosystem integrity (AGI). AGI means, the capacity of both maintenance of its \"primitive\" properties and supplies public ecosystem service. Reaching the proposed goal, the LUC dynamic was mapping through both Landsat-TM image classification and aerial photography from 1962 to 2011. The LST has been obtained by remote sensing technique through Lansat-TM thermal band to the years 1985, 1990, 1995, 1999, 2002 and 2011. The ECS analyze was carried out by soil sample collected in different type of LUC: forest native, sugar cane, pasture and orchard, in the 0-10 and 10-20 cm depths. The results have indicated both the BRC of the LST and SOC are influenced by both together LUC and crop tillage. Furthermore, some agricultural policy adopted during from 1962 to 2011 influenced the LUC dynamic, thus the CRB agro ecosystem capacity of supply agro ecosystem services as well as provided environmental cost. The interdisciplinary approach employed, with the use of geotechnologies, has shown to be able to assessment the CRB agro ecosystem integrity, it can supports the LUC planning in order to maximize the benefit/cost ratio anthropic activities, considering both the LST and ECS. Such an approach can be applied in several knowledge areas to evaluation of sustainability and agro ecosystem environmental integrity.
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Surfaces of constant visual acuity in symmetric dioptric power spaceRubin, Alan 28 August 2012 (has links)
D.Phil. / Visual acuity and refractive state probably are the two most basic or fundamental quantities that concern optometry, ophthalmology and vision science. Both of these variables are complicated and their mathematical and statistical use in research and other activities has been poorly understood. During particularly the last decade, modern statistical multivariate methods have become available to optometry and ophthalmology and this has assisted with the understanding of concepts such as refractive state (and its underlying nature, namely, dioptric power). It is now possible to transform measurements of refractive state from the conventional notation that is commonly used in the fields of optometry and ophthalmology to an orthodox mathematical form that can be understood by scientists and mathematicians. With this matrix form of refractive state it then is possible to use appropriate methods of linear algebra and multivariate statistics. Other theoretical approaches and analytical procedures or methods also have become accessible or have been developed recently as a consequence of this significant shift in thought as regards the fundamental nature of dioptric power. On the other hand, the scientific understanding of visual acuity (that is, the measurement of the resolving ability of the eye) perhaps has been somewhat neglected. Certainly there has been an abundance of research involving visual acuity and there also has been discussion concerning some of the difficulties that become apparent when measuring or attempting to interpret results from studies involving visual acuity. Visual acuity, unlike refractive state, can be represented by means of a single number and thus univariate, rather than multivariate, statistical methods are appropriate. And, of course, univariate statistics is less complicated than the multivariate form. But there are various difficulties with the understanding and researching of visual acuity. Some of these difficulties are relatively simple and thus can be solved more easily. For example, visual acuity measurements can be obtained from charts designed according to a logarithmic scale, or measurements from other charts can be transformed to a logarithmic scale. And thereby the ordinal nature of the basic or more common visual acuity scale is avoided and certain statistical methods become available that otherwise would not be possible. But more fundamentally visual acuity probably cannot truly be considered without the subject from which the measurement is obtained and, more particularly, the refractive state of the eye concerned. So the visual acuity and refractive state of an eye, perhaps, should be more appropriately regarded as a unitary concept that ideally should not be separated into two distinct parts. Thus to truly understand the relationship between visual acuity and refractive state we need to understand the 4-dimensional (mathematical) nature of the particular relationship involved. It follows then that the relationship between visual acuity and refractive state is a multivariate problem and that multivariate methods are best suited to its consideration. If we then begin to take into account other variables such as age or the ocular health, or say, iris aperture diameter of the eye then the complicated multivariate nature of the situation becomes even more obvious. In this dissertation an attempt is made to consider the possibilities of a modern multivariate approach to studies involving visual acuity, refractive state and other variables. The methodology used in this dissertation differs from those used in previous studies involving visual acuity and refractive state and other related variables. For example, here Jackson crossed cylinders are used extensively to produce dioptric blur or defocus in experimental subjects (positive and negative spheres also are used to a more limited extent). In previous published studies spherical or, less commonly, cylindrical lenses were used instead. Another difference between this dissertation and previous research studies is that the visual stimulus that the subjects observed, generally but not always, was a meridionally-independent or non-directional letter 0. The reasons for this choice is explained in the dissertation but in other research an enormous variety of visual stimuli have been used depending upon the interests of the researchers. But even more essentially this dissertation differs significantly from that of previous studies in terms of the manner in which the various experimental and other results (for instance, that from earlier researchers such as HB Peters) are presented. Entirely new, and largely unpublished, methods are used in many parts of this dissertation that probably represent a paradigmatic transition in understanding of visual acuity and its relation to refractive state. New terms such as decompensation and accompensation surfaces of constant visual acuity and antistigmatic ellipses are defined herein. (Briefly, one imagines starting from a state of compensation (of the refractive state of, say, an eye viewing a stimulus).
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On using AMOS, EQS, LISREL, Mx, RAMONA and SEPATH for structural equation modelingPeprah, Syvester January 2000 (has links)
Structural Equation Modeling is a common name for the statistical analysis of Structural Equation Models. Structural Equation Models are models that specify relationships between a set of variables and can be specified by means of path diagrams. A number of Structural Equation Modeling programs have been developed. These include, amongst others, AMOS, EQS, LISREL, Mx, RAMONA and SEPATH. A number of studies have been published on the use of some of the applications mentioned above. They include, amongst others, Brown (1986), Waller (1993) and Kano (1997). Structural Equation Models are increasingly being used in the social, economic and behavioral sciences. More and more people are therefore making use of one or more of the Structural Equation Modeling applications on the market. This study is performed with the aim of using each of the Structural Equation Modeling applications AMOS, EQS, LISREL, Mx, RAMONA and SEPATH for the first time and document the experience, joy and the difficulties encountered while using them. This treatise is different from the comparisons already published in that it is based on the use of AMOS, EQS, LISREL, Mx, RAMONA and SEPATH to fit a Structural Equation Model for peer influences on ambition, which is specified for data obtained by Duncan, Haller and Portes (1971), by myself as a first time user of each of the programs mentioned. The impressive features as well as the difficulties encountered are listed for each application. Recommendations for possible improvements to the various applications are also proposed. Finally, recommendations for future studies on the use of Structural Equation Modeling programs are made.
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[en] METHODOLOGIC FOR ASSESSMENT OF RURAL ELECTRIFICATION PROGRAM THROUGH MULTIVARIATE ANALYSIS / [pt] METODOLOGIA PARA AVALIAÇÃO DO PROGRAMA DE ELETRIFICAÇÃO RURAL VIA ANÁLISE MULTIVARIADACRISTIANE FARIAS CAMACHO 10 July 2003 (has links)
[pt] A realidade vivida pela população rural tem sempre
surpresas a revelar e mais ainda quando se trata do meio
rural não eletrificado. Este estudo examina uma parte da
realidade do cotidiano vivido por propriedades rurais
envolvidas no Programa de Eletrificação Rural Luz no Campo,
mostrando o modo de vida das propriedades na fase anterior
ao recebimento de energia elétrica.
Através do data mining dos dados coletados na pesquisa de
campo do estado do Mato Grosso do Sul e da aplicação de
técnicas de análise multivariada, tais como: Análise de
Fatores e Análise de Cluster, este estudo possibilitará a
visualização do modo de vida de propriedades não
eletrificadas permitindo posteriormente a comparação com a
chegada da energia elétrica que propiciará a avaliação do
Programa de Eletrificação Rural. O modelo foi aplicado em
dados de duas concessionárias de energia elétrica do Brasil
usando dados horários coletados durante dois anos. / [en] The reality lived by the rural population has always some
surprises to reveal, even more when it's about the not
electrified rural domain. This research examines a part of
the reality lived by homestead involved in the Rural
Electrification Program Luz no Campo, showing their way of
life in the previous phase of the electricity receipt.
Through the data mining of the collected data in the field
research in Mato Grosso do Sul state and with the
application a varied of statistical multivariate
techniques such as: Factors Analysis and Cluster Analysis,
this research will provide the visualization of the way of
life of non electrified properties allowing a later
comparison with the data collected in the same properties,
after the arrival of the electricity. This way, it will be
possible to establish a formal evaluation of the Rural
Electrification Program.
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The application of quantitative structure activity relationship models to the method development of countercurrent chromatographyMarsden-Jones, Siân Catherine January 2016 (has links)
A fundamental challenge for liquid-liquid separation techniques such as countercurrent chromatography (CCC)and centrifugal partition chromatography (CPC), is the swift, efficient selection of the two phase solvent system containing more than two solvents, for the purification of pharmaceuticals and other molecules. A purely computational model that could predict the optimal solvent systems for separation using just molecular structure would be ideal for this task. The experimental value being predicted is the partition coefficient (Kd), which is the concentration of the compound in one phase divided by the concentration in the other. Using this approach, Quantitative Structure Activity Relationship (QSAR) models have been developed to predict the partitioning of compounds in two phase systems from the molecular structure of the compound using molecular descriptors. A Kd value in the range of 0.5 to 2 will give optimal separation. Molecular descriptors are varied, examples include logP values, hydrogen bond donor values and the number of oxygen atoms. This work describes how the QSAR models were developed and tested. A dataset of experimental logKd values for 54 compounds in six different combinations of four solvents (heptane, ethyl acetate, methanol and water) was used to train the QSAR models. A set of 196 possible molecular descriptors was generated for the 54 compounds and a partial least squares regression was used to identify which of these was significant in the relationship between logKd and molecular structure. The resulting models were used to predict the logKd values of four test compounds that had not been used to build the QSAR models. When these predictions were compared to the experimental logKd values, the root mean squared error for four of the six models was less than 0.5 and less than 0.7 for the remaining two. These models were used to successfully separate a range of structurally diverse pharmaceutical compounds by predicting the best solvent systems to carry out the separation on the CCC/CPC using nothing but their molecular structure.
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Statistical analysis of gene expression data in cDNA microarray experimentsZhao, Hongya 01 January 2006 (has links)
No description available.
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Les populations du Néolithique moyen autour du Bassin lémanique : une approche anthropométrique / Middle neolithic populations around Lemanic basin : an anthropomometrical approachCivetta, Aude 15 January 2010 (has links)
Le Néolithique moyen (4500-3500 av. J.-C) est une période transitoire entre deux phases importantes de la préhistoire récente : la néolithisation des territoires occidentaux de l’Europe au Néolithique ancien et la multiplication des identités culturelles au Néolithique final. Longtemps considérée comme une période de « stabilisation » des groupes humains, les recherches archéologiques ont montré la complexité de cette période particulière de la Préhistoire récente. Les Alpes se situent à la confluence de plusieurs aires chronoculturelles et présentent à ce niveau un intéressant terrain d’étude. Notre étude se porte sur plusieurs populations appartenant à cette phase chronologique. Plusieurs analyses statistiques univariées et multivariées ont été effectuées à partir des données métriques crâniennes et infracrâniennes des groupes appartenant à la région du Bassin lémanique afin de percevoir leur variabilité diachronique. Puis, ils ont été comparés à des populations chronologiquement similaires, mais appartenant à d’autres aires chronoculturelles voisines. La morphologie crânienne ne nous a pas permis de mettre en évidence de variations dans les groupes lémaniques au cours du millénaire considéré, qui paraissent ainsi présenter une certaine stabilité morphologique. Toutefois, un gradient morphologique est perceptible entre les différentes populations occidentales considérées dans notre échantillon. La forme et le format infracrâniens nous ont permis d’avancer plusieurs hypothèses quant aux conditions et modes de vie de ces différentes populations. Ils remettent en question la définition initiale des populations du Néolithique moyen à savoir une réduction du format et une tendance à la gracilisation et montrent, au contraire, une certaine variation des caractères de forme et de format qui semble dépendante du contexte environnemental dans lequel évoluaient ces groupes humains. / The mid Neolithic period (4500-3500 BC) is a transitional one, between two important phases of recent prehistory: neolithization of western Europe’s territories in the ancient neolithic period and the multiplication of cultural identities in the final Neolithic period. For a long time, it has been considered the « stabilisation » period of the human groups. Archaeological research has shown the complexity of this particular period of recent prehistory. The Alps are located at the confluence of several chronocultural eras and are thus an interesting study ground. Our study deals with several populations of this particular chronological period. Several statistical analysis, univariate and multivariate, were carried out using cranial and infracranial metric based data on groups from the Geneva lake Basin to determine their diachronic variability. Then they were compared to other similar populations of the same period, from neighbouring areas. The cranial morphology based findings did not highlight any variations in Geneva Basin groups during the millennium studied which seems to prove a morphological stability. However, a morphological gradient is discernible between the different western populations sampled. Infracranial shapes and sizes have allowed us to put forward several hypotheses about the conditions and way of life during that period of time. They question the initial definition of middle Neolithic population, i.e. format reduction and a tendency to slenderness, but show on the contrary a certain form and size variation, which seem to be dependant on the environmental context in which these human groups were living.
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Development of an antiretroviral solid dosage form using multivariate analysisNqabeni, Luxolo January 2007 (has links)
The aim of pharmaceutical development is to design a quality product and the manufacturing process to deliver the product in a reproducible manner. The development of a new and generic formulation is based on a large number of experiments. Statistics provides many tools for studying the conditions of formulations and processes and enables us to optimize the same while being able to minimize our experimentation. The purpose of this study was to apply experimental design methodology (DOE) and multivariate analysis to the development and optimization of tablet formulations containing 150 mg lamivudine manufactured by direct compression.
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