Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work, it is developed a study of the transverse vibrations of a system composed by two parallel strings of equal length, coupled by a viscoelastic element. The frequencies and mode shapes are obtained using modal analysis and a block matrix formulation for the system. The mode shapes are written by the dynamic basis, composed by the solution of a second order problem with impulsive initial conditions, and its first derivative. In the undamped case, different cases of the problem are considered by varying the parameters of the strings. The orthogonality of the mode shapes and the impulse response matrix are used to solve the undamped forced case. In the damped case, it is considered again the matrix formulation and use dynamic basis, and we present an uncoupled problem from simplifications of the system parameters. The damped forced vibrations are studied using the adjoint modal method, from which there is an orthogonality between the mode shapes of the original system and the mode shapes of the adjoint system associated, allowing the uncoupling and solvability of the system. The forced response is determined by using the matrix fundamental response. / Neste trabalho é realizado um estudo sobre as vibrações transversais de um sistema formado por duas cordas paralelas, de mesmo comprimento, acopladas através de um elemento viscoelástico do tipo Winkler. As frequêencias e os modos de vibração são obtidos utilizando-se a análise modal e uma formulação matricial em blocos para o sistema. Os modos de vibração são escritos através da base dinâmica, composta pela solução de um problema de segunda ordem com condições iniciais impulsivas, e sua primeira derivada. No caso não amortecido são considerados diferentes casos para o problema, variando-se os parãmetros das cordas. A ortogonalidade dos modos e a resposta impulso matricial são usadas para resolver o caso forçado sem amortecimento. No caso amortecido, é apresentado um problema desacoplado a partir de simplificações nos parâmetros do sistema. As vibrações forçadas com amortecimento são estudadas usando-se o método modal adjunto, a partir do qual, existe uma ortogonalidade entre os modos de vibração do sistema original e os modos de vibração do sistema adjunto, possibilitando o desacoplamento e resolução do sistema. A resposta forçada é determinada usando a resposta fundamental matricial.

Le coeur de cette thèse porte sur la modélisation géométrique et introduit une méthode robuste d'extraction de formes tubulaires à partir de nuages de points. Nous avons choisi de tester nos méthodes dans le contexte applicatif de la foresterie pour mettre en valeur la robustesse de nos algorithmes.Nos méthodes intègrent les normales aux points, il est donc nécessaire de les pré-calculer. Notre premier développement a alors consisté à présenter une méthode rapide d'estimation de normales. Pour ce faire nous avons approximé localement la géométrie du nuage de points en utilisant des "patchs" lisses dont la taille s'adapte à la complexité locale des nuages de points.Nos travaux se sont ensuite concentrés sur l’extraction robuste de formes tubulaires dans des nuages de points occlus, bruités et de densité inhomogène. Nous avons développé une variante de la transformée de Hough que nous avons couplé à une proposition de contours actifs indépendants de leur paramétrisation. Notre méthode a été validée en environnement forestier pour reconstruire des troncs d'arbre afin d'en relever les qualités par comparaison à des méthodes existantes.La reconstruction de troncs d'arbre ouvre d'autres questions dont la segmentation des arbres d'une placette forestière. Nous proposons également une méthode de segmentation pour isoler les différents objets d'un jeu de données.Durant nos travaux nous avons utilisé des approches de modélisation pour répondre à des questions géométriques, et nous les avons appliqué à des problématiques forestières. Il en résulte un pipeline de traitements cohérent qui, bien qu'illustré sur des données forestières, est applicable dans des contextes variés. / The core of this thesis concerns geometric modelling and introduces a fast and robust method for the extraction of tubular shapes from point clouds. We chose to test our method in the difficult applicative context of forestry in order to highlight the robustness of our algorithms.Our methods integrate normal vectors, thus they have to be pre-computed. Our first development consisted in the development of a fast normal estimation method on point cloud. To do so, we locally approximated the point cloud geometry using smooth "patches" of points which size adapts to the local complexity of the point cloud geometry.We then focused our work on the robust extraction of tubular shapes from dense, occluded, noisy point clouds suffering from non-homogeneous sampling density. We developed a variant of the Hough transform and combined this research with a new definition of parametrisation-invariant active contours. We validated our method in complex forest environments with the reconstruction of tree stems to emphasize its advantages and compare it to existing methods.Tree stem reconstruction also opens new perspectives halfway in between forestry and geometry such as the segmentation of trees from a forest plot. Therefore we propose a segmentation approach capable of isolating objects inside a point cloud.During our work we used modelling approaches to answer geometric questions and we applied our methods to forestry problems. Therefore, our studies result in a processing pipeline adapted to forest point cloud analyses, but the general geometric algorithms we propose can also be applied in various contexts.

Submitted by JEAN-JACQUES ARMAND VIDAL null (je.jacvi@yahoo.com.br) on 2017-05-17T01:26:09Z No. of bitstreams: 1 repositório Doutorado.pdf: 41703688 bytes, checksum: 81eff3f181fa51f11a08b3377f9188d4 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-05-17T12:34:53Z (GMT) No. of bitstreams: 1 vidal_jja_dr_ia.pdf: 41703688 bytes, checksum: 81eff3f181fa51f11a08b3377f9188d4 (MD5) / Made available in DSpace on 2017-05-17T12:34:53Z (GMT). No. of bitstreams: 1 vidal_jja_dr_ia.pdf: 41703688 bytes, checksum: 81eff3f181fa51f11a08b3377f9188d4 (MD5) Previous issue date: 2017-03-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este estudo propõe-se a apresentar a cerâmica de dois povos indígenas da Amazônia, os Paiter Suruí de Rondônia e os Asurini do Xingu. No caso dos Suruí, trata-se do ponto de vista dos homens, dois professores e lideranças, sobre o que representam na cultura Paiter Suruí as cerâmicas produzidas pelas ceramistas e sobre os desdobramentos de uma pesquisa feita em 2010 com as artistas Paiter Suruí (VIDAL, J., 2011). Para os Asurini, trata-se de uma pesquisa de campo e o estudo dos procedimentos de fabricação da cerâmica, as formas, os usos e a decoração dos vasilhames, tanto no ambiente domestico como ritualístico. Dá-se ênfase ao estudo dos grafismos pela sua importância nesta sociedade. Com base em quatro estudos recentes sobre cerâmica ameríndia (Karaja, Waúja, Palikur e Wayana) feitos por antropólogos, destaca-se a diversidade das produções cerâmicas indígenas e como ao longo da história pós contato elas passam por adaptações diversificadas, devido à comercialização dos artefatos produzidos. Tratamos de responder às perguntas: por que, como e em que condições a cerâmica indígena continua (ou não) a ser produzida? Por que ela resiste? / The aim of this paper is to present the pottery of two indigenous tribes of the Amazon, the Paiter Suruí from Rondônia, and the Asurini from Xingu. In the case of the Suruí tribe, it is considered the point of view of two men, two professors and leaders, showing what the pottery produced by the artisans represent to the Paiter Suruí culture, as well as the results of a research done in 2010 with the artisans in the Paiter Suruí tribe (VIDAL, J., 2011). For the Asurini, the approach is a field research as well as the analysis of the procedures for the manufacturing of the pottery, its shapes, the uses and the decoration of the containers, both in the domestic and the ritualistic environments. Emphasis is placed upon the study of the graphics due to its importance in that society. Based on four recent studies of the Amerindian pottery (Karajas, Waúja, Palikur and Wayana) carried out by anthropologists, one should highlight the diversity of the indigenous pottery production, and how it has gone through different adaptations throughout the post-contact history due to the commercialization of the items. We try to answer the questions: why, how and under what conditions is indigenous pottery still (or not) being produced? Why does it resist?

The dissertation in general describes the characteristic of socialy pathological phenomene that pupils encounter both at school and at their prevention. The dissertation includes an empirial survey carried out at two select primary schools. The surveyed values have been processed and evaluated. The focus of the survey was to establish the awareness of the pupils and their experience with socially pathological phenomen. The empirial survey further deals with the effects of prevention at the sekond degrese of primary school.

O cenário de metrópoles como Londres, Nova Iorque, Dubai, Shangai, Seul e outras exibe alguns tipos de edifícios com formas orgânicas e fluidas, que fazem parte de uma proposta que utiliza ferramentas informacionais e programação para a sua criação e materialização. Este trabalho investiga como viabilizar as superfícies consideradas complexas, desses edifícios, através do tema Projeto para a Produção, etapa que aprofunda o processo do fazer, posterior à criação. A complexidade é caracterizada pela utilização de um alto nível tecnológico para a elaboração dos sistemas, do componente em sua morfologia e, em relação ao módulo, material e geometria (PAOLETTI, 2006). Para o entendimento do problema, o texto contextualiza o momento contemporâneo e a participação dos instrumentos digitais no cotidiano, fazendo uma retrospectiva dos modos de produção e da automação da indústria, e faz um paralelo com a construção civil. Trata desde a 1a. Revolução Industrial até a 4a. Revolução Industrial, de acordo com Schwab (2016).Para discutir o Projeto para a Produção, verifica-se o estado da arte, posteriormente confrontando duas vertentes conceituais da atuação do papel do arquiteto no processo: uma que defende que os profissionais têm atuado mais próximos à fabricação digital, com arquivos enviados diretamente para a fábrica File to Factory (Arquivo-Fábrica) , e outra que entende que o processo é distribuído em etapas e equipes específicas e depende de habilidades e conhecimentos particulares para a produção do objeto. Este trabalho apresenta dois casos desenvolvidos na Itália: o primeiro projetado pelos arquitetos do escritório Norman Foster & Associates, o Pavilhão da União dos Emirados Árabes para a exposição internacional de Milão, que foi confeccionado com painéis de argamassa armada estampados com a textura das dunas do deserto, e o segundo, a torre corporativa do escritório Zaha Hadid Architects, do complexo CityLife Milano, que possui a superfície de vedação com painéis de vidro em formato de paralelogramas, que evidenciam a torção da torre em seu eixo vertical. Finalmente, o trabalho propõe um modelo de Projeto para a Produção de superfícies complexas a partir do aprofundamento dos estudos de caso, considerando que a proposta faz parte de uma etapa do projeto que é efetuada por equipes de profissionais habilitados para a elaboração dos detalhamentos, busca de soluções, pesquisa aprofundada a respeito dos materiais a serem utilizados e dos requisitos necessários para a realização dos trabalhos no local de implantação. / The scenery of big cities such as London, New York, Dubai, Shanghai and Seoul exhibits some types of buildings with organic and fluid shapes that are part of a proposal that uses information tools and programming for their creation and feasibility. This work in¬vestigates how feasible surfaces considered complex through the theme Design for Pro¬duction, a stage that deepens the process of making, after creation. The complexity is characterized as the use of a high technological level for the elaboration of the systems, of the component in its morphology and, in relation to the module, material and geom¬etry (PAOLETTI, 2006). For the understanding of the problem, the text contextualizes the contemporary moment and the participation of the digital instruments in the daily life, making a retrospective of the ways of production and the automation of the industry and parallels with the civil con¬struction. It deals from the 1st. Industrial Revolution until the 4th. Industrial Revolution, according to Schwab (2016). In order to discuss the Design for Production, the state of the art is verified, later confront¬ing two conceptual aspects of the role of the architect in the process, one that argues that the professionals have directly acted in the digital manufacture with files sent directly to the factory File to Factory and another that understands that the process is distribut¬ed in stages and specific teams and depends on particular skills and knowledge to the production of the object. It presents two cases developed in Italy: the first one designed by Norman Foster & As-sociates, the United Arab Emirates Pavilion for the Milan International Exbition, which was made with panels of Glass Fiber Reinforced Concret stamped with the texture of the desert dunes and the second one a corporate tower designed by Zaha Hadid Architects office for the CityLife Milano, which has a trapezoidal glass panel sealing surface that demonstrates the twisting of the tower on its vertical axis. Finally, the work proposes a model of a Design for Production of complex surfaces from the deepening of the case studies, considering that the proposal is part of a project stage carried out by teams of professionals qualified to perform the details, search for solutions, in-depth research regarding the materials to be used and the requirements necessary to carry out the works at the place of implantation.

Les capacités des technologies de télédétection ont augmenté exponentiellement au cours des dernières années : de nouveaux scanners fournissent maintenant une représentation géométrique de leur environnement sous la forme de nuage de points avec une précision jusqu'ici inégalée. Le traitement de nuages de points est donc devenu une discipline à part entière avec ses problématiques propres et de nombreux défis à relever. Le coeur de cette thèse porte sur la modélisation géométrique et introduit une méthode robuste d'extraction de formes tubulaires à partir de nuages de points. Nous avons choisi de tester nos méthodes dans le contexte applicatif difficile de la foresterie pour mettre en valeur la robustesse de nos algorithmes et leur application à des données volumineuses. Nos méthodes intègrent les normales aux points comme information supplémentaire pour atteindre les objectifs de performance nécessaire au traitement de nuages de points volumineux.Cependant, ces normales ne sont généralement pas fournies par les capteurs, il est donc nécessaire de les pré-calculer.Pour préserver la rapidité d'exécution, notre premier développement a donc consisté à présenter une méthode rapide d'estimation de normales. Pour ce faire nous avons approximé localement la géométrie du nuage de points en utilisant des "patchs" lisses dont la taille s'adapte à la complexité locale des nuages de points. Nos travaux se sont ensuite concentrés sur l’extraction robuste de formes tubulaires dans des nuages de points denses, occlus, bruités et de densité inhomogène. Dans cette optique, nous avons développé une variante de la transformée de Hough dont la complexité est réduite grâce aux normales calculées. Nous avons ensuite couplé ces travaux à une proposition de contours actifs indépendants de leur paramétrisation. Cette combinaison assure la cohérence interne des formes reconstruites et s’affranchit ainsi des problèmes liés à l'occlusion, au bruit et aux variations de densité. Notre méthode a été validée en environnement complexe forestier pour reconstruire des troncs d'arbre afin d'en relever les qualités par comparaison à des méthodes existantes. La reconstruction de troncs d'arbre ouvre d'autres questions à mi-chemin entre foresterie et géométrie. La segmentation des arbres d'une placette forestière est l'une d’entre elles. C'est pourquoi nous proposons également une méthode de segmentation conçue pour contourner les défauts des nuages de points forestiers et isoler les différents objets d'un jeu de données. Durant nos travaux nous avons utilisé des approches de modélisation pour répondre à des questions géométriques, et nous les avons appliqué à des problématiques forestières.Il en résulte un pipeline de traitements cohérent qui, bien qu'illustré sur des données forestières, est applicable dans des contextes variés. / Abstract : The potential of remote sensing technologies has recently increased exponentially: new sensors now provide a geometric representation of their environment in the form of point clouds with unrivalled accuracy. Point cloud processing hence became a full discipline, including specific problems and many challenges to face. The core of this thesis concerns geometric modelling and introduces a fast and robust method for the extraction of tubular shapes from point clouds. We hence chose to test our method in the difficult applicative context of forestry in order to highlight the robustness of our algorithms and their application to large data sets. Our methods integrate normal vectors as a supplementary geometric information in order to achieve the performance goal necessary for large point cloud processing. However, remote sensing techniques do not commonly provide normal vectors, thus they have to be computed. Our first development hence consisted in the development of a fast normal estimation method on point cloud in order to reduce the computing time on large point clouds. To do so, we locally approximated the point cloud geometry using smooth ''patches`` of points which size adapts to the local complexity of the point cloud geometry. We then focused our work on the robust extraction of tubular shapes from dense, occluded, noisy point clouds suffering from non-homogeneous sampling density. For this objective, we developed a variant of the Hough transform which complexity is reduced thanks to the computed normal vectors. We then combined this research with a new definition of parametrisation-invariant active contours. This combination ensures the internal coherence of the reconstructed shapes and alleviates issues related to occlusion, noise and variation of sampling density. We validated our method in complex forest environments with the reconstruction of tree stems to emphasize its advantages and compare it to existing methods. Tree stem reconstruction also opens new perspectives halfway in between forestry and geometry. One of them is the segmentation of trees from a forest plot. Therefore we also propose a segmentation approach designed to overcome the defects of forest point clouds and capable of isolating objects inside a point cloud. During our work we used modelling approaches to answer geometric questions and we applied our methods to forestry problems. Therefore, our studies result in a processing pipeline adapted to forest point cloud analyses, but the general geometric algorithms we propose can also be applied in various contexts.

The study was undertaken with three Grade 9 teachers at three selected schools which are part of RUMEP’s Collegial Cluster Schools’ programme that I coordinate. Collegial clusters are communities of teachers who aim at improving their practice by working on their own professional development. The purpose of this study was to investigate the selected Grade 9 teachers’ experiences of a Geoboard intervention programme. It also wanted to investigate the role that a Geoboard can play in the teaching and learning of area and perimeter of two-dimensional shapes. The research was a case-study within the interpretive paradigm. A variety of data collection techniques was used. These included baseline assessment tasks, observations during the intervention programme, post intervention assessment tasks and semistructured interviews with the participating teachers and a few learners from each participating school. The collected data was analysed using both the quantitative and qualitative methods. My research findings reveal that a Geoboard, as a manipulative, developed confidence in the participating teachers. In the interviews with teachers, it transpired that teachers’ skills in teaching area and perimeter of two-dimensional shapes had been sharpened. According to the interviews with learners, the use of a Geoboard led to better conceptual understanding of the area and perimeter, as learners no longer had to rely on formulae. Kilpatrick et al. (2001) refer to conceptual understanding as an integrated functional grasp of mathematical ideas. The post intervention assessment task showed a positive shift in learners’ performance. The average learner performance improved from 29% in the baseline assessment task to 61% in the post intervention assessment task. This shows that the use of a Geoboard led to meaningful learning of area and perimeter of two-dimensional shapes. The overall research findings reveal that the use of manipulatives has a positive impact in the teaching and learning of area and perimeter. Learners’ responses to the interview questions showed that there was better understanding of the two concepts, which enabled them to construct their own knowledge. They further said the Geoboard allowed them to be hands-on, which contributed to their active involvement in the lesson.

This work presents the results from the analysis of the behavior of demand and energy consumption in the Campus of the Universidade Federal de Santa Maria to contribute to the adoption of strategic plans for demand side management. Presented are the basic concepts of electrical quantities, the definition of demand, as well as its available control and management techniques. The advantages of the demand side management option are highlighted. Two sets of load curves were collected : the load shapes of the campus as a whole, obtained from two years of demand records by the local electricity provider's energy meter; and the individual load curves of various buildings throughout the campus, obtained from measurements made with a multi-quantities electrical meter. Presented are the methods of obtaining their curves and highlighted the influence of temperature, business hours, school calendar and days of the week on them. Finally, a comparison is made between the whole university curve, with the individual load shapes. The set of information obtained forms the basics for demand side management on the campus, in near future. The results indicated that public educations buildings have peculiarities that should be taken into account when adopting measures to reduce consumption and load management. Such measures must take into account the presence of loads of different nature (purely academic through industrial, commercial and residential) and with different hours of use in comparison to similar off-campus loads. / Neste trabalho são apresentados os resultados obtidos a partir do estudo do comportamento da demanda e do consumo de energia elétrica no Campus da Universidade Federal de Santa Maria de forma a contribuir para a adoção de planos estratégicos de gerenciamento pelo lado da demanda. São apresentados os conceitos básicos das grandezas elétricas, a definição de demanda, bem como seu controle e técnicas de gerenciamento possíveis. As vantagens da opção do gerenciamento pelo lado da demanda são evidenciadas. Dois conjuntos de curvas de carga foram levantados: as curvas de carga do campus como um todo, obtidas a partir de dois anos de registros junto ao medidor de energia da concessionária local; as curvas de carga individuais de diversos prédios espalhados pelo campus, obtidas a partir de medições realizadas com um multimedidor de grandezas elétricas. São apresentados os métodos de obtenção das respectivas curvas e evidenciadas a influência da temperatura, horário de expediente, calendário letivo e dia da semana sobre as mesmas. Por fim, é feita a comparação entre a curva de carga geral da universidade, com as curvas de carga individuais. O conjunto de informações obtidas forma a base para um futuro gerenciamento pelo lado da demanda no campus. Os resultados obtidos permitiram concluir que os prédios públicos de ensino apresentam peculiaridades que devem ser levadas em conta quando se adotam medidas de redução do consumo e gerenciamento de carga. Tais medidas devem levar em conta a presença de cargas de diferentes naturezas (puramente acadêmicas, passando por industriais, comerciais e residenciais) e com horários de uso diferenciados em comparação a cargas idênticas fora do campus.

Contemporary laser research involves the development of spectroscopic techniques to understand the microscopic structural aspects of a simple molecular system in chemical and materials to more complex biological systems such as cells. In particular, Raman spectroscopy, which provides bond specific information, has attracted considerable attention. Further with the advent of femtosecond (fs) laser, the recent trend in the field of fs chemistry is to develop nonlinear Raman techniques that allow one to acquire vibrational structural information with both fs temporal resolution as well as good spectral resolution. Among many advanced nonlinear Raman techniques, the development of fs Stimulated Raman scattering (SRS) has gathered momentum in the recent decade due to its ability to (1) provide vibrational structural information of various system including fluorescent molecules with good signal to noise ratio and (2) circumvent the limitation imposed on the spectral resolution by the necessary pulse durations according to the energy-time uncertainty principle where ‘K’ is a constant that depends on the pulse shape) unlike in the case of fs normal resonance Raman spectroscopy. We have developed a technique named “Ultrafast Raman loss spectroscopy (URLS)” that is analogues to SRS, but is more advantageous as compared to SRS and has the potential to be an alternative if not competitive tool as a vibrational structure elucidating technique. The concept and the design of this novel technique, URLS, form the core of the thesis entitled “Ultrafast Raman Loss Spectroscopy (URLS)”. Chapter 1 lays the theoretical groundwork for ultra-short pulses and nonlinear spectroscopy which forms the heart of URLS. It presents a detailed discussion on the basis behind the elementary experimental problems associated with the ultra-short laser pulses when they travel through a medium, the characterization of these ultrashort pulses as well as various non-linear phenomena induced within a medium due to the propagation of these pulses. Chapter 2 focuses on the concept of SRS which resulted into the foundation of URLS. It illustrates the theoretical as well as the experimental aspects of SRS and demonstrates the sensitivity of SRS over normal Raman spectroscopy. Chapter 3 introduces the conceptual and the technical basis which ensued into the development of URLS while Chapter 4 demonstrates its application and efficiency over its analogue SRS. URLS involves the interaction of two laser sources, viz. a picosecond (ps) pulse and a fs white light (WL), with a sample leading to the generation of loss signal on the higher energy (blue) side with respect to the wavelength of the ps pulse unlike the gain signal observed on the lower energy (red) side in SRS. These loss signals are at least 1.5 times more intense than SRS signals. Also, the very prerequisite of the experimental protocol for signal detection to be on the higher energy side by design eliminates the interference from fluorescence, which appears on the red side. Thus, the rapid data acquisition, 100% natural fluorescence rejection and experimental ease ascertain “Ultrafast Raman Loss Spectroscopy (URLS)” as a unique valuable structure determining technique. Further, the effect of resonance on the line shape of the URLS signal has been studied which forms the subject of discussion in Chapter 5. The objective of the study is to verify whether the variation of resonance Raman line shapes in URLS could provide an understanding of the mode specific response on ultrafast excitation. It is found that the URLS signal’s line shape is mode dependent and can provide information similar to Raman excitation profile (REP) in the normal Raman studies. This information can have impact on the study of various dynamical process involving vibrational modes like structural dynamics and coherent control. Chapter 6 demonstrates the application of URLS as a structure elucidating technique for monitoring ultrafast structural and reaction dynamics in both chemical and biological systems using α-terthiophene (3T) as the model system. The objective is to understand the mechanism of the molecular structure dependent electronic relaxation of the first singlet excited state, S1, of α-terthiophene using fs URLS. The URLS data along with the ab-initio calculations indicate that the electronic transition is associated with a structural rearrangement from a non-planar to a planar configuration in the singlet manifold along the ring deformation co-ordinate. The experimental findings suggest that the singlet state decays exponentially with a decay time constant ( 1/e) of about 145 ps and this decay could be assigned to the intersystem crossing (ISC) pathway from the relaxed S1 state to the vibrationally hot triplet state, T1*. Lastly, Chapter 7 summarizes the entire thesis and presents some possible future prospects for URLS. Considering the advantages of URLS, it is proposed that URLS can be exploited [1] to determine the structure of any fluorescent/non-florescent condensed materials and biological systems with a very good spectral resolution (10- 40 cm-1); [2] to obtain the vibrational signature of weak Raman scattering molecules and vibrational modes with relatively small Raman cross-section owing to its high detection sensitivity with good signal to noise ratio; [3] for performing fs time-resolved study by introducing an additional fs pulse for photo-excitation of the molecule and using URLS to probe the excited state dynamics with good temporal (fs) and spectral (10-40 cm-1) resolution; and lastly, [4] the high chemical selectivity of URLS and the fact that the signal is generated only within the focal volume of the lasers where all the beams overlap can be utilized for developing this method into a microscopy for labeled-free effective vibrational study of biological samples. Consequently, it is hoped that this technique, “Ultrafast Raman Loss Spectroscopy (URLS)”, would be a suitable alternative to other nonlinear Raman methods like coherent anti-Stokes Raman spectroscopy (CARS) that has made major inroads into biology, medicine and materials.

The diploma thesis is focused on vibration of the planar plates. It includes the computational and experimental approaches used to determine the mode shapes and frequencies (eigenvalues) of planar plates. This paper compares the analytical, numerical and experimental results of the modal analysis specifically the free-standing rectangular planar plate. The work also encompasses forced oscillation with harmonious excitement as a continuation of the obtained results from modal analysis.