946 resultados para Non-destructive method


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The mechanisms that reduce the viability of plant somatic embryos following cryopreservation are not known. The objective of the present study was to evaluate the sensitivity of cocoa (Theobroma cacao L.) somatic embryos at different stages of an encapsulation-dehydration protocol using stress-related volatile hydrocarbons as markers of injury and recovery. The plant stress hormone ethylene and volatile hydrocarbons derived from hydroxyl radicals (methane) and lipid peroxidation (ethane) were determined using gas chromatography headspace analysis. Ethylene and methane were the only volatiles detected, with both being produced after each step of the cryogenic protocol. Ethylene production was significantly reduced following exposure to liquid nitrogen, but then increased in parallel with embryo recovery. In contrast, the production of methane was cyclic during recovery, with the first cycle occurring earlier for embryos recovered from liquid nitrogen and desiccation than those recovered from earlier steps in the protocol. These results suggest that loss of somatic embryo viability during cryopreservation may be related to the oxidative status of the tissue, and its capacity to produce ethylene. This study has demonstrated that headspace volatile analysis provides a robust non-destructive analytical approach for assessing the survival and recovery of plant somatic embryos following cryopreservation.

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Thermal non-destructive testing (NDT) is commonly used for assessing aircraft structures. This research work evaluates the potential of pulsed -- transient thermography for locating fixtures beneath aircraft skins in order to facilitate accurate automated assembly operations. Representative aluminium and carbon fibre aircraft skin-fixture assemblies were modelled using thermal modelling software. The assemblies were also experimentally investigated with an integrated pulsed thermographic evaluation system, as well as using a custom built system incorporating a miniature un-cooled camera. Modelling showed that the presence of an air gap between skin and fixture significantly reduced the thermal contrast developed, especially in aluminium. Experimental results show that fixtures can be located to accuracies of 0.5 mm.

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Rolling Contact Fatigue (RCF) is one of the main issues that concern, at least initially, the head of the railway; progressively they can be of very high importance as they can propagate inside the material with the risk of damaging the railway. In this work, two different non-destructive techniques, infrared thermography (IRT) and fibre optics microscopy (FOM), were used in the inspection of railways for the tracing of defects and deterioration signs. In the first instance, two different approaches (dynamic and pulsed thermography) were used, whilst in the case of FOM, microscopic characterisation of the railway heads and classification of the deterioration -- damage on the railways according to the UIC (International Union of Railways) code, took place. Results from both techniques are presented and discussed.

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Mannitol is a polymorphic excipient which is usually used in pharmaceutical products as the beta form, although other polymorphs (alpha and delta) are common contaminants. Binary mixtures containing beta and delta mannitol were prepared to quantify the concentration of the beta form using FT-Raman spectroscopy. Spectral regions characteristic of each form were selected and peak intensity ratios of beta peaks to delta peaks were calculated. Using these ratios, a correlation curve was established which was then validated by analysing further samples of known composition. The results indicate that levels down to 2% beta could be quantified using this novel, non-destructive approach. Potential errors associated with quantitative studies using FT-Raman spectroscopy were also researched. The principal source of variability arose from inhomogeneities on mixing of the samples; a significant reduction of these errors was observed by reducing and controlling the particle size range. The results show that FT-Raman spectroscopy can be used to rapidly and accurately quantitate polymorphic mixtures.

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Terahertz (THz) radiation is being developed as a tool for the analysis of cultural heritage, and due to recent advances in technology is now available commercially in systems which can be deployed for field analysis. The radiation is capable of penetrating up to one centimetre of wall plaster and is delivered in ultrafast pulses which are reflected from layers within this region. The technique is non-contact, non-invasive and non-destructive. While sub-surface radar is able to penetrate over a metre of wall plaster, producing details of internal structures, infrared and ultraviolet techniques produce information about the surface layers of wall plaster. THz radiation is able to provide information about the interim region of up to approximately one centimetre into the wall surface. Data from Chartres Cathedral, France, Riga Dome Cathedral, Latvia, and Chartreuse du Val de Bénédiction, France is presented each with different research questions. The presence of sub-surface paint layers was expected from documentary evidence, dating to the 13th Century, at Chartres Cathedral. In contrast, at the Riga Dome Cathedral surface painting had been obscured as recently as 1941 during the Russian occupation of Latvia using white lead-based paint. In the 13th Century, wall paintings at the Chapel of the Frescos, Chartreuse du Val de Benediction in Villeneuve les Avignon were constructed using sinopia under-painting on plaster covering uneven stonework.. This paper compares and contrasts the ability of THz radiation to provide information about sub-surface features in churches and Cathedrals across Europe by analysing depth based profiles gained from the reflected signal. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

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To date, limited numbers of dental calculus samples have been analyzed by researchers in diverse parts of the world. The combined analyses of these have provided some general guidelines for the analysis of calculus that is non-destructive to archaeological teeth. There is still a need for a quantitative study of large numbers of calculus samples to establish protocols, assess the level of contamination, evaluate the quantity of microfossils in dental calculus, and to compare analysis results with the literature concerning the biology of calculus formation. We analyzed dental calculus from 53 teeth from four Brazilian sambaquis. Sambaquis are the shell-mounds that were established prehistorically along the Brazilian coast. The analysis of sambaqui dental calculi shows that there are relatively high concentrations of microfossils (phytoliths and starch), mineral fragments, and charcoal in dental calculus. Mineral fragments and charcoal are possibly contaminants. The largest dental calculi have the lowest concentrations of microfossils. Biologically, this is explained by individual variation in calculus formation between people. Importantly, starch is ubiquitous in dental calculus. The starch and phytoliths show that certainly Dioscorea (yam) and Araucaria angustifolia (Parana pine) were eaten by sambaqui people. Araceae (arum family), Ipomoea batatas (sweet potato) and Zea mays (maize) were probably in their diet. (C) 2009 Elsevier Ltd. All rights reserved.

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The report examines the factors which may be a contributing cause to the problems that are present when ferritic stainless steel are eddy current tested in a warm condition. The work is carried out at Fagersta Stainless AB in Fagersta which manufactures stainless steel wire. In the rolling mill there is an eddy current equipment for detection of surface defects on the wire. The ferritic stainless steels cause a noise when testing and this noise complicates the detection of defects.Because of this, a study was made of how the noise related to factors such as steel grade, temperature, size and velocity. By observing the signal and with the possibilities to change the equipment settings the capability to let a signal filter reduce the noise level were evaluated. Theories about the material's physical properties have also been included, mainly the magnetic properties, electrical conductivity and the material's tendency to oxidize.Results from the tests show that a number of factors do not affect the inductive test significantly and to use a filter to reduce the noise level does not seem to be a viable option. The level of noise does not relate to the presence of superficial particles in form of oxides.The ferritic stainless steels showed some difference in noise level. Which noise level there was did match well with the steels probability for a precipitation of a second phase, and precipitation of austenite may in this case contribute to noise when using an eddy current instrument.The noise is probably due to some physical material property that varies within the thread.

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A aquisição do ciclo pressão-volume é de grande importância para diagnóstico de cardiopatias e principalmente para o acompanhamento de intervenções terapêuticas, porém os métodos hoje utilizados são caros e agressivos ao paciente, reduzindo por estes motivos sua aplicação. Este estudo pretende obter, por métodos não-invasivos, o ciclo pressão-volume do ventrículo esquerdo de pacientes humanos. Isto consiste na aquisição dos sinais P(t) e V(t) simultaneamente e a apresentação de um gráfico P(V). Para tanto, após a revisão bibliográfica, decidiu-se utilizar a ecocardiografia com detecção automática de bordos, para obtenção do volume ventricular e a medição da onda de pressão transmitida através da artéria braquial para um manguito inflado com ar, conectado a um transdutor piezo-resistivo em ponte. A aquisição da pressão pelo método não-invasivo é comparada a dados resultantes da aquisição invasiva da pressão arterial por catéter intra-aórtico que é considerado padrãoouro. Os sinais são condicionados e digitalizados em uma placa de aquisição com conversor A/D de 8 bits e micro controlador 80c196. Os dados digitalizados são então enviados serialmente para um computador onde são gerados os gráficos. Obteve-se de cinco pacientes nove aquisições simultâneas da pressão invasiva através de catéter intra-aórtico e do protótipo desenvolvido resultando concordância segundo o método de Bland e Altman (1986) (r=0,989; d + 2s= 6,52; d - 2s =-6,07), comprovando a eficiência do método de aquisição. Obteve-se resultado satisfatório também quanto à operação sistema desenvolvido pois foram realizadas dez aquisições em cinco pacientes, registrando-se gráficos bastante similares aos apresentados na literatura disponível.

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This Thesis is the result of my Master Degree studies at the Graduate School of Economics, Getúlio Vargas Foundation, from January 2004 to August 2006. am indebted to my Thesis Advisor, Professor Luiz Renato Lima, who introduced me to the Econometrics' world. In this Thesis, we study time-varying quantile process and we develop two applications, which are presented here as Part and Part II. Each of these parts was transformed in paper. Both papers were submitted. Part shows that asymmetric persistence induces ARCH effects, but the LMARCH test has power against it. On the other hand, the test for asymmetric dynamics proposed by Koenker and Xiao (2004) has correct size under the presence of ARCH errors. These results suggest that the LM-ARCH and the Koenker-Xiao tests may be used in applied research as complementary tools. In the Part II, we compare four different Value-at-Risk (VaR) methodologies through Monte Cario experiments. Our results indicate that the method based on quantile regression with ARCH effect dominates other methods that require distributional assumption. In particular, we show that the non-robust method ologies have higher probability to predict VaRs with too many violations. We illustrate our findings with an empirical exercise in which we estimate VaR for returns of São Paulo stock exchange index, IBOVESPA, during periods of market turmoil. Our results indicate that the robust method based on quantile regression presents the least number of violations.

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O objetivo desta dissertação é analisar a forma de atuação do CMDS, e sua contribuição para a gestão dos recursos hídricos nos cinco municípios do Rio de Janeiro pertencentes à bacia do rio Itabapoana. O presente estudo foi conduzido a partir de uma discussão teórica sobre os temas: desenvolvimento local, cidadania, desenvolvimento local com cidadania e gestão social. Posteriormente, foram realizadas entrevistas temáticas, baseadas no método não probabilístico, com uma amostra composta por 38 pessoas, entre conselheiros do CMDS (membros do poder público e sociedade civil organizada), técnico, consultores e gestores do Sebrae/RJ. No tratamento dos dados foi utilizada a análise de discurso. Foram identificados aspectos negativos e positivos no que diz respeito à atuação e funcionamento do Conselho nos municípios analisados. Mesmo assim, pode-se verificar que grande parte dos conselheiros tem experiência anterior em Conselhos e movimentos sociais, e que o Projeto Managé, por meio da atuação dos CMDS, ajudou a construir uma identidade territorial para a bacia e também despertou a necessidade de maior conscientização e preservação do meio ambiente. Pode-se concluir que a forma de atuação do CMDS depende da interação e do nível de comprometimento do poder público e da sociedade civil organizada. Portanto, as condições institucionais locais exercem importante influência nas formas de mobilização social e participação dos indivíduos, visto que o processo de gerenciamento de recursos hídricos da bacia encontra-se ainda em fase de construção

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The purpose of this dissertation is to analyze the Casa Brasil Project and its contribution for promoting actions related to citizenship in Vitoria and Vila Velha cities. The essay was led through a theoretical discussion about citizenship, public space, social participation and public politics. Thereafter thematic interviews based on a non-probabilistic method were done with seventeen people such as public power representatives, organized civilian society and community. The speech analysis was used for data treatment. Some negative and positive aspects referred to citizenship and public power were identified. The aim of the research was checking if there is any encouragement to a genuine and consciousness participation of the society for the structure and continuous citizenship practice. The Casa Brasil Project experience in Vitoria and Vila Velha demonstrates that its sustainability and effectiveness depend on how interacted and committed the strategic stakeholders are, since the condition of local institutions influences the model of social mobilization and individual participation. Besides, this essay shows it is necessary: to improve the citizen involvement ¿ by implementing the board of directors, which assures public participation in order to stimulate the community to take the unity control ¿ to grant democratic feature to the public power, and to increase citizenship.

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Tourism as an example of alternative for sustainable development in the Lençóis Maranhenses. The objective of this work is to analyze the prospects for sustainable development in tourism in the aforementioned region. An attempt is made to evaluate the five dimensions of sustainable - ecological, economic, social, space and cultural. The base for discussion is the information gathered from the people who actually live in the region. A type of the case study was built up. The research involved speaking with the people about the viability of tourism projects, not only with an eye on economic success, job creation and income for the region. There was also an attempt to tackle the issue of social and environment impact. Data was collected through verbal contact. A variety of people were interviewed, locals, businessmen, authorities, civil representatives and they spoke about the advantages and disadvantages of tourism as the saw it and as it affected them. Their answers and comments constitute the knowledge gleaned. The development of possible new strategies is the result of this work. Strategies that should be investigated by the local government/public administration. One such strategy would involve strengthening ties whit society and hoping that the improved dialogue would encourage sustainability. Another would mean improving interdepartmental contact to streamline the performance of public bodies so that development can be better planned and non-destructive.