Made available in DSpace on 2014-12-17T15:04:51Z (GMT). No. of bitstreams: 1 JoseAS.pdf: 1036248 bytes, checksum: 0a1a59bfb5a6c32769649beb4f986093 (MD5) Previous issue date: 2008-07-31 / Placed in the field of Didactic of Science, this paper proposes an approach to the introduction of the History of Science in science education, at high school level. It was designed and implemented a series of activities regarding the history of the Principle of Inertia. The aim of this approach was to give more meaning to scientific education, while opening new avenues for a better understanding of the processes of construction of scientific knowledge. The preparation of the activities involved a study of the historical development of the concept of motion, from the Aristotelian physics through physical movement concepts at medieval period, from Galileo, Gassendi, Descartes, until the first law of Newton. The strategy of teaching was applied to three classes of high school (night period) of a state public school at the city of Natal (RN). The results indicated the difficulty of overcoming alternative conceptions about movement by students. Nevertheless, we consider that the implementation of this strategy of teaching both represented gains for the learning of students, and contributed to the resizing of pedagogical practices of the teacher-researcher / Inserido no campo da Did?tica das Ci?ncias, este trabalho prop?e uma abordagem para a introdu??o da Hist?ria da Ci?ncia no ensino cient?fico, em n?vel m?dio. Foi elaborada e aplicada uma seq??ncia de atividades contemplando a hist?ria do Princ?pio da In?rcia. Procurou-se, com tal abordagem, dar mais significado ao ensino cient?fico e, ao mesmo tempo, abrir novas vias para uma melhor compreens?o dos processos de constru??o do conhecimento cient?fico. A prepara??o das atividades envolveu um estudo do desenvolvimento hist?rico do conceito de movimento, desde a f?sica aristot?lica, passando pela f?sica do movimento medieval, por Galileu, Gassendi, Descartes, at? alcan?ar a primeira lei de Newton. A estrat?gia de ensino foi aplicada a tr?s turmas do ensino m?dio noturno de uma escola da rede p?blica estadual da cidade de Natal (RN). A an?lise dos resultados indicou a dificuldade de supera??o de concep??es alternativas acerca de movimento pelos estudantes. Apesar disso, avaliamos que a aplica??o dessa estrat?gia de ensino tanto representou ganhos para a aprendizagem dos estudantes, como contribuiu para o redimensionamento da pr?tica pedag?gica do professor-pesquisador

Sistemas alostéricos são característicos de proteínas com um ou mais estados de equilíbrio. Nesse sentido, uma enzima passa por modificações de sua atividade quando um substrato cooperativo se liga a um estado ou outro (1). Estes estados são reconhecidos por possuírem uma conformação mais estável e coexistirem num ensemble. Este trabalho sustenta que tais proteínas oscilem naturalmente entre esses estados. Experimentos de difração de raios-X e RMN, que proporcionam parâmetros de deslocamento anisotrópicos e tempos de relaxação de spin nuclear, já demonstram a coexistência de ambos estados em solução e descrevem o movimento como uma mudança de equilíbrio populacional dos confórmeros (2). Também é possível desenvolver métodos numéricos, como o cálculo de modos normais e a simulação de dinâmica molecular, para associar a geometria proteica a um movimento sobre determinado potencial de campos de força. O sistema adotado para o desenvolvimento desses estudos é a enzima alostérica Glucosamina-6-fosfato Desaminase. Características que defendem seu uso são sua reversibilidade catalítica, rápido equilíbrio cinético e muito baixa afinidade do estado T por ligantes. Sua estrutura também já foi resolvida por experimentos de cristalografia, identificando ambos estados alostéricos. E a caracterização das mudanças estruturais entre os estados T e R está bem estabelecida, identificando diferentes subunidades a distintos graus de rotação e prevendo uma oscilação de baixa frequência entre eles (3). Resultados obtidos neste projeto constituem: (a) uma dinâmica de 100ns partindo do estado T de toda a proteína (hexamérica) solvatada explicitamente, formando um ensemble NVT de 92000 átomos através do programa NAMD, usando o campo de forças CHARMM; (b) análise de componentes principais aproveitando esta dinâmica e usando algoritmos do programa Gromacs; (c) e análise de modos normais, em que os cálculos de minimização de energia foram feitos pelo programa Gromacs sob o campo de forças ENCADV, no vácuo. Análises desses resultados envolvem cálculos de RMSDs e flutuações, trajetórias calculadas para os autovetores oriundos de NMA ou de PCA, fatores de Debye-Waller e a confirmação visual (e gráficos de distância entre resíduos) de aproximação a um estado ou outro. Como a prévia caracterização da movimentação alostérica, identificava duas regiões para cada monômero como representativas de corpos rígidos, também é desenvolvida uma análise por tensores de inércia. Espera-se que, ao longo do tempo, essas subunidades se comportem como corpos quase rígidos e os movimentos destas regiões rígidas correspondam a uma maior representatividade da transição alostérica. Assim, a caracterização dos tensores seria capaz de filtrar movimentos de mais alta frequência que constituem ruído em relação a movimentos funcionais da proteína. - Algoritmos para cálculos matriciais dos tensores foram escritos em Fortran e em TCl. / Allosteric systems are characteristic of proteins with one or more equilibrium states. Such an enzyme experiences a modification of its activity when a cooperative substrate binds to a state or another, thus, establishing a change in population equilibrium (1). These states are recognized by having a more stable conformation, and they coexist in an ensemble. X-ray diffraction and NMR experiments already demonstrated this dynamic equilibrium, and simulation methods, as molecular dynamics and normal mode analysis, generally provide a more complete proof (2).The allosteric enzyme Glucosamine-6-Phosphate Deaminase appeared to be a good model to better understand the equilibrium dynamics as essential to the protein function, given its reversibility of the catalysis and rapid-equilibrium kinetic mechanism. It also has the structure elucidated for both its conformers (3). A computational approach would now give better perspective on how the conformational changes occur. A set of results of this latter kind were obtained: (a) a 100ns dynamic starting at the hexameric T conformer, explicitly solvated, building a NVT ensemble using NAMD program and CHARMM force field; (b) a principal components analysis making use of the calculated dynamic and of the Gromacs algorithms; (c) and normal mode analysis of the T conformer structure (pdb code 1fsf) minimized with Gromacs program using ENCADV vacuum force field. Not only the conventional analyses for these results (fluctuations and projections) were taken, but also an inertia tensor analysis was developed. As the allosteric conformational change, for this protein, was described by the displacement of only two rigid body subunits³, its description by inertia tensors should act as a filter for the high frequency and functionally uninteresting motions, which normally constitute only noise.

Orientadores: Inacio Maria Dal Fabbro, Leila Martins / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-17T22:21:55Z (GMT). No. of bitstreams: 1 Fracarolli_JulianaAparecida_M.pdf: 1740641 bytes, checksum: 3b58affa12601dc23d779d12bd0a1f66 (MD5) Previous issue date: 2011 / Resumo: O ipê-roxo (Tabebuia heptaphylla (Vellozo) Toledo) é uma espécie de alto valor econômico, ornamental e medicinal, pertencente à família Bignoniaceae, cuja multiplicação ocorre prioritariamente por sementes. Há considerável necessidade de estudos sobre o desempenho fisiológico das unidades de dispersão dessa e de outras espécies florestais. O objetivo desse trabalho foi avaliar a potencialidade do biospeckle, técnica baseada no fenômeno óptico de interferência, como ferramenta de caracterização do potencial germinativo das sementes de ipê-roxo. A quantificação do biospeckle foi expressa através do cálculo do Momento de Inércia (MI). Foram utilizados laser vermelho (632 nm de comprimento de onda) e 10 mW de potência, câmera filmadora digital e computador. Foram realizados cinco experimentos, a saber: (1) Avaliação de danos térmicos em sementes através do biospeckle; (2) Avaliação da interferência do tegumento na sensibilidade do biospeckle; (3) Diferenciação entre sementes germinadas e não germinadas através do biospeckle; (4) Determinação da faixa de umidade das sementes para a melhor interação entre o laser e a semente para o biospeckle; (5) Avaliação de sementes de ipê-roxo submetidas ao envelhecimento acelerado através do biospeckle. Para os experimentos 1, 2, 3 e 4 as sementes foram hidratadas até atingirem grau de umidade de 69%, divididas em quatro sub-amostras sendo que duas delas foram submetidas ao congelamento. Em seguida as sub-amostras foram separadas em 5 níveis de umidade (28, 35, 54, 63, 69%) e iluminadas com laser. Nesses ensaios foram planejados quatro tratamentos: (1) sementes sem tegumento; (2) sementes com tegumento; (3) sementes sem tegumento submetidas a congelamento a 0°C e (4) sementes com tegumento submetidas ao congelamento a 0°C. Os resultados permitem afirmar que é possível diferenciar as sementes que sofreram dano térmico daquelas que não sofreram através do biospeckle. A presença do tegumento interfere na sensibilidade do biospeckle. É possível diferenciar as sementes viáveis das inviáveis através do biospeckle. Do experimento 4 obteve-se uma correlação positiva entre os valores de MI e de umidade das sementes. Verificou-se também que a faixa de teor de água para a melhor interação entre o laser e a semente de ipê-roxo está entre 28 e 54%. Esta faixa de umidade das sementes foi utilizada como referência para o experimento 5. No experimento 5 as sementes foram submetidas ao envelhecimento acelerado (42°C e umidade relativa do ar de 100 % durante 24, 48, 72, 96 e 120 horas) e avaliadas através da técnica do biospeckle e teste de germinação. Obteve-se que é possível detectar a redução de viabilidade e vigor das sementes de T. heptaphylla ocasionada pelo envelhecimento acelerado. Dessa forma, o biospeckle é uma técnica que vem sendo desenvolvida e apresenta-se como uma ferramenta possível para avaliar o potencial germinativo das sementes de ipê-roxo / Abstract: Ipê-roxo (Tabebuia heptaphylla (Vellozo) Toledo) is considered of very important economical, ornamental, as well as medicinal value which is included in the Bignoniaceae botanical family which multiplication is quite solely carried by seeds. Forest dispersion elements, i.e., the seeds, deserve a deep understanding of their physiological performance. The objective of this research work was to evaluate a biospeckle method potential in testing seed viability, which is based on the laser interferometry. The biospeckle phenomenon quantification was carried by means of the Moment of Inertia (MI) which formula resembles its mechanical counterpart. The equipment employed in the experimental setup included a 632 nm red diode laser of 10mW, a digital movie camera as well as a PC. The five tests carried were (1) thermal damage evaluation on seeds, (2) biospeckle sensitivity to the tegument interference, (3) differentiation between non germinated and germinated seeds evaluation by the biospeckle, (4) determination of the best seed moisture content to laser interaction and (5) evaluation of accelerated aging ipê-roxo seeds through the biospeckle. In tests 1, 2, 3 and 4 seeds were hydrated to the value of 69% and divided into four sub samples from which two of them were forwarded to freezing. Following the four sub samples were separated into five moisture level groups (28, 35, 54, 63, 69%) and exposed to the laser. Four treatments have been imposed to the experimental tests, named (1) seeds without teguments, (2) seeds with tegument, (3) frozen at 0° C seeds without teguments and (4) frozen at 0° C seeds with teguments. Results from biospeckle tests confirm the possibility of differentiating seeds with thermal damage from those without thermal damage. When the tegument is covering the seed, the sensitivity of biospeckle is affected.?It's possible to differentiate viable seeds from non viable seeds using biospeckle technique. From test (4) it is obtained a positive correlation between MI and seeds moisture content. It was also verified that seed moisture content between 28% and 54% showed better interaction with laser. That moisture content range was adopted for the test (5). Seeds were submitted to accelerated aging process in the test (5) (42°C and 100% of relative humidity for 24, 48, 72, 96 and 120 hours) following by biospeckle evaluation and germination tests. It was concluded that viability reduction of T. heptaphylla as generated by accelerated aging can be detected by the biospeckle test. Thus, the biospeckle is a technique that has been developed and is presented as a possible tool to assess the germination potential of ipê-roxo seeds / Mestrado / Maquinas Agricolas / Mestre em Engenharia Agrícola

Orientador: Leandro Palermo Jr / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-09T15:27:34Z (GMT). No. of bitstreams: 1 Sakanaka_SandraHiromi_M.pdf: 2300706 bytes, checksum: bf530823f185b6dbee7f56dd83d01a67 (MD5) Previous issue date: 2006 / Resumo: A análise de vibração livre e de instabilidade de placas finas e placas moderadamente espessas é apresentada através do método dos elementos de contorno (MEC) considerando o efeito da deformação pela força cortante e, particularmente para o cálculo de freqüências naturais, o efeito da inércia rotatória é também considerado. A formulação da solução fundamental é baseada na teoria de Mindlin (1951) mas resultados para a teoria de Kirchhoff (1850) também podem ser obtidos [Palermo Jr. (2000)]. O presente trabalho usa a técnica da iteração inversa através do coeficiente de Rayleigh para a determinação das menores freqüências naturais e cargas críticas de instabilidade das placas. A implementação numérica emprega elementos de contorno isoparamétricos lineares contínuos e descontínuos. Elementos constantes de domínio são usados. Os parâmetros nodais são posicionados nos extremos dos elementos e os pontos de carregamento dos elementos descontínuos são deslocados para o interior a uma distância igual a um quarto do comprimento do elemento. Expressões analíticas das integrais de contorno são desenvolvidas para os casos em que o elemento contém o ponto de carregamento e integração numérica de Gauss-Legendre é feita nos outros casos. As integrais de domínio foram transformadas em integrais de contorno para cada célula e foram tratadas como cargas de superfície atualizadas através de um processo iterativo. Os resultados obtidos foram comparados com valores encontrados na literatura para demonstrar a precisão do presente trabalho / Abstract: Free-vibration analysis and static buckling loads analysis of thin and thick plates considering the shear deformation effects using the Boundary Element Method (BEM) is presented. For the calculation of natural frequencies, the rotatory inertia is also counted. The formulation of the fundamental solution considers Mindlin¿s plates but results according to the classic theory can also be obtained [Palermo Jr. (2000)]. The present article makes use of the inverse iteration with Rayleigh coefficient to determine the smallest natural frequencies and the smallest static buckling loads of the plates. The numerical implementation employed continuous or discontinuous isoparametric linear boundary elements according to the characteristics of the problem to be solved. Constant domain elements are used. Nodal parameters have been placed at the ends of the elements and the source point of the discontinuous elements were positioned at a distance equal to one quarter of the element length. Analytical expressions have been employed in the integration on elements containing the source point and Gauss-Legendre numerical integration scheme otherwise. The domain integrals containing the inertia effects or nonlinear effect have been transformed into boundary integrals for each cell and were treated as surface loads updated in an iterative process. The obtained results were compared to those in literature to demonstrate the precision of this proposal / Mestrado / Estruturas / Mestre em Engenharia Civil

Utilizando a survey junto ao consumidor da universidade de Michigan, obtivemos dados a respeito das expectativas dos agentes não só sobre inflação, mas também sobre nível de atividade (os estudos de Roberts (1997) utilizaram apenas os dados de survey sobre expectativas inflacionárias). Verificamos, então, que grande parcela do custo das estabilizações dos EUA foi antecipado pela maior parte dos agentes, o que nos levou a rejeitar os modelos de Taylor (1979, 1980) e de Calvo (1983), mesmo em suas versões com as hipóteses de falta de credibilidade e informação homogeneamente defasada. Em seguida discutimos como um modelo com fairness, pode explicar este quebra cabeças. Finalmente, examinamos, três possíveis fatores (mutuamente compatíveis): a hipótese de que parte da população tenha expectativas inconsistentes, incerteza knightiana e o modelo com fairness. Nossos resultados empíricos penderam a favor de uma combinação de pelo menos uma das duas últimas alternativas com a primeira. / Using the Michigan Universitys consumer survey, we obtained data about agents expectations of both inflation and output (the latter had not been used in Roberts (1997) studies). With this, we were able to verify that a great part of the sacrifice ratios of the US stabilizations were anticipated by common agents, rejecting the Taylor (1979, 1980) and Calvo (1983) models and, with it, the hypothesis that the only reasons underlying them are staggered contracts, homogeneous sticky information and lack in credibility. WE, then, discuss how a model with fairness can explain this puzzle. Finally, we examine three (mutually consistent) factors: the hipothesis that part of the population have inconsistent expectatitons, Knightian uncertainty and te model with fairness. The results favored the combination of at least one of the two latter alternatives with te former.

Assessment, an integral part of teaching and learning, is a planned process of identifying, gathering and interpreting information about the performance of students. However, concerns have been raised about how assessment is being conducted in schools and so the aim of this study is to investigate and improve assessment practices used by Grade 12 secondary school Physics teachers in Mozambique, Africa. The study addresses the question of what assessment practices do Grade 12 teachers in Physics in Mozambique apply and how can they be improved? and it adopted a twofold research approach. A Baseline Survey aimed at gaining an overall impression of the assessment practices used by secondary school Physics teachers and an Intervention Study aimed at producing improvements on teacher assessment practices. The preliminary research followed a survey research method, while the intervention applied an educational design research approach. In the survey three questions were investigated: (i) What assessments practices do Grade 12 Physics teachers apply? (ii) What is the quality of the assessment practices? and (iii) How relevant can the assessment practices be for student learning?To address these questions a purposive sample of 12 Physics teachers, four school directors and five educational officers was selected. The survey was conducted in six secondary schools purposefully selected throughout the country and data were collected via interviews, questionnaires, classroom observations and written notes. The Intervention Study was designed to answer the question of how teacher assessment practices can be improved.This phase of the study involved a design, a classroom tryout, and a systematic evaluation of a series of exemplary Physics assessment materials (prototypes) in a context of demonstration experiments. The prototypes were developed for the concepts of force and inertia and their validity and practicality were verified using appraisal by experts, university students, teachers, and students. Classroom tryout was conducted with two teachers and their 62 students in two secondary schools. Baseline Survey findings indicate that the most used assessment practices in schools are paper-and-pencil tests, verbal tests, and homework, while projects, portfolios, and peer assessments are the less frequently used ones. Oral communication during lessons, written work, presentations, notebooks, laboratory work, and ability to solve problems were used as quality criteria for the teachers’ assessment. It was shown that the most frequently assessed student activity was written work, followed by the ability of students to solve problems, while laboratory work was the activity that was never assessed by many of the researched teachers. Another quality criterion used was the type of feedback given by teachers to students, which indicated that teachers were giving expressed (both congratulatory and critical), personal and timely feedback. It emerged that teachers often involve the students in the evaluation of their performance through reflection of assessment results and in addition, encourage students to engage in active learning. Findings from the Intervention Study indicate that (i) teachers liked the presentation and structure of the materials following the Predict-Observe-Explain (POE) strategy and regarded their personal commitment as crucial for achieving the desired experimental results; (ii) students also liked most the POE strategy because it allowed them to develop their own explanations of the observed events and highlighted the role of teachers during the tryout as crucial for the success of the experiments. The main conclusion of this study is that assessment practices undertaken by Physics teachers in Mozambican secondary schools are of poor quality and there is a need for improvement. This must be done by developing and applying exemplary assessment materials with the potential to improve performance assessment practices associated with demonstration experiments in Physics. The study recommends that the Ministry of Education and Culture and teacher training institutions should promote the training of teachers in developing exemplary assessment materials for their own use in schools. These materials should contain specific guidelines on how to conduct effective assessment practices. / Thesis (PhD)--University of Pretoria, 2008. / Curriculum Studies / unrestricted

Conventional vehicle suspensions consist of a spring and a damper, while mass is rarely used. A mass, if properly used, can also create a damping-like effect. However, a mass has only one terminal which makes it difficult to be incorporated into a suspension. In order to use a mass to achieve the damping-like effect, a two-terminal mass (TTM) has to be designed. However, most of the reported TTMs are of fixed moment of inertia (TTM-CMI), which limits the further improvement of the suspension performance and responsiveness to changes in environment and driving conditions. In this study, a TTM-based vibration absorber with variable moment of inertia (TTM-VMI) is proposed. The main component of the proposed TTM absorber contains a hydraulic-driven flywheel with sliders. The moment of inertia changes with the positions of the sliders in response to the driving conditions. The performance of the proposed TTM-VMI absorber has been analyzed via dynamics modeling and simulation and further examined by experiments. The analysis results indicate that the TTM-VMI absorber outperforms the TTM-CMI design in terms of body displacement; and ride comfort, tire grip and suspension deflection for zero and impulse inputs with comparable performance for sinusoidal input.

Ce travail de thèse est consacré à la caractérisation physique de la surface de Mars et à l'étude des facteurs dynamiques la modifiant. Deux aspects sont étudiés. Le premier concerne les propriétés thermo-physiques qui sont un moyen de contraindre les actions que les forces érosives et sédimentaires cumulées sur les temps géologiques ont joué à la surface de Mars. Le second est l'hydratation de la surface de Mars qui est une donnée importante du système climatique martien en tant que réservoir d'eau.Afin de caractériser ces deux propriétés physiques de la surface de Mars, nous avons combiné l'approche orbitale permettant une couverture globale, l'approche in situ qui fournit une interprétation locale robuste et l'utilisation d'outils de simulation des processus physiques. Les données des instruments OMEGA, un spectro-imageur à bord de Mars Express en orbite autour de Mars depuis 2004, et le capteur de température de surface de l'instrument REMS, embarqué à bord de Curiosity et en opération dans le cratère Gale depuis 2012 ont été analysées en détail. Les mesures de température de surface de ces deux instruments ont été inversées pour caractériser les propriétés thermo-physiques de la surface au moyen d'un modèle climatique. Nous présentons la première carte globale de l'inertie thermique de la surface de Mars calculées à partir des données OMEGA et nous mettons en évidence de manière inédite des comportements thermiques spécifiques d'assemblages hétérogènes à la surface de Mars ou de processus physiques négligés.Les informations relatives à l'hydratation de la surface ont pu être extraites des données OMEGA grâce à la prise en compte de mesures en laboratoire et ont été interprétées de concert avec les résultats de plusieurs missions autour ou à la surface de Mars et des simulations climatiques du cycle de l'eau afin de reconstruire l'histoire de cette hydratation. Nous trouvons que l'hydratation est stable tout au long de l'année martienne et qu'elle augmente avec la latitude de manière asymétrique entre les deux hémisphères. La distribution spatiale de l'hydratation coincide avec les zones en contact régulier avec des dépôts de givre, qui apparaît ainsi être à l'origine du processus responsable de l'implémentation de l'eau dans le régolite martien. / This thesis work is devoted to the physical characterization of the Martian surface and to the study of dynamic processes modifying it. Two aspects are addressed. The first concerns the thermo-physical properties which are a mean to putting constraints on to the erosive and sedimentary actions summed over the geologic history. The second is the hydration of the Martian surface which plays, as a planetary reservoir of water, an important role on the Martian climate.In order to characterize these two physical parameters of the Martian surface, we have combined the orbital view which allows a global coverage with in situ measurements, which provides a robust local interpretation, and we have used tools allowing numerical simulations of physical processes. Data from OMEGA, an imaging spectrometer onboard Mars Express orbiting Mars since 2004, and from the ground temperature sensor of the REMS instrument onboard Curiosity have been analyzed in details. Surface temperature measurements from these two instruments have been inverted using a climate model for characterizing the thermo-physical properties of the Martian surface. We present the first global map of the Martian surface thermal inertia constructed from OMEGA data and we directly highlight for the first time some thermal behavior caused by heterogeneous mixtures or neglected physical processes at the surface of Mars.Information regarding the hydration of the Martian surface have been extracted from OMEGA data using a large set of laboratory experiments. This information has been interpreted together with scientific results from multiple mission orbiting or at the surface of Mars and with numerical simulations of the Martian water cycle in order to reconstruct the history of this hydration. We find that the hydration remains stable throughout the whole Martian year and that it increases with latitude with an asymetry between the two hemispheres. The spatial distribution of the hydration fits areas that are in regular contact with water frost, which therefore seems to be involved in the process of water implementation in the Martian regolith.

How long would modern society cope with a power outage, what would happen to vital systems that we today take for granted in modern society. The Nordic electricity grid is facing a major shift where electricity production from non-renewable sources are to be replaced increasingly by renewable sources. By increasing the penetration of wind and solar power the electric power system might be exposed to disturbances due to decreasing inertia as a result of the electricity transition. Currently the electric power system has different reserves to use to maintain frequency stability but there are other reserves that could help further in the fight for the balance between electricity production and consumption. This project examines whether the new reserve service, fast frequency reserve (FFR), can help the existing frequency containment reserve for disturbed (FCR-D) operation. Therefore, two experiments were conducted using the simulation tool ARISTO, addressing relevant issues involving frequency stability. Motivation for the hypothesis was to investigate if FFR could reduce the frequency transients and improve frequency variations by developing various setups and cases when inertia was retained and when the system inertia was reduced at different stages. The results of the experiments showed that the global minimum frequency, nadir, had increased for all test cases compared to the reference case when using FFR, this proved that the FFR in fact help reducing frequency transients. The results showed furthermore that when the FFR had a duration time of 30 seconds compared to only 5 seconds, the frequency variations could be improved for certain setups for experiment 2.

In order to reach climate and environmental goals, Sweden is increasing the implementation of intermittent renewable energy sources such as wind and solar power to the electricity grid. The increase of intermittent energy sources is rising power regulation requirement towards hydropower, which increasingly exposes the hydraulic turbines to high loads and fluctuating hydraulic forces. These conditions affect the turbine’s structural and rotor dynamic behavior, leading to fatigue in turbine components. Identifying the parameters that affect the dynamics of the water turbine is an essential part of analyzing and, if possible, avoiding these situations. Furthermore, accurate rotor dynamic models are necessary to design for a robust hydropower unit and improve the estimate of wear on turbine components. Added parameters (added mass, polar moment of inertia, and damping) are hydrodynamic effects occurring due to interaction between structural vibrations and surrounding fluid. Added parameters can modify the turbine’s natural frequencies and consequently its dynamic behavior. Therefore, it is of interest to study and quantify the impact of these parameters on the turbine for accurate rotor dynamic modeling and turbine design. The added parameters have been investigated by conducting experiments on a model Kaplan runner, for which the project has been divided into two consecutive parts. First, experiments were performed in a test rig, in which the runner was excited in a lateral movement to determine added mass and linear damping. Secondly, experiments were performed in a test rig similar to the first, except the runner was excited in a torsional movement to determine added polar moment of inertia and torsional damping. Force and displacement have been measured during both movements, with the runner placed in air and thereafter in quiescent water. The added parameters were quantified by comparing measurements conducted with the runner in air against those conducted in water. By varying the excitation frequency and amplitude, added parameters have been analyzed against excitation frequency, velocity, and acceleration to determine dependent variables. The dimensionless added mass ratio, γma, was investigated within a range of acceleration of 0.07m/s2 to 5.00 m/s2 and in an excitation frequency of 2-9 Hz. Results exhibited a frequency-dependent added mass ratio, leading to a mass addition variation of 1.00-1.49 times the test rig mass with a mean γma of 1.22. Similarly, the dimensionless added polar moment of inertia, γIp, was investigated within a range of angular acceleration between 2.4 rad/s2 to 29.6 rad/s2 and in an excitation frequency range of 2-10 Hz. The mean added polar inertia ratio, γIp, was obtained as 1.09 times the polar moment of inertia of the test rig, corresponding to an increase in polar inertia of about 9%, compared to the total dry polar inertia of the test rig. Results showed that the added polar inertia ratio varied by approximately 1.8% within the studied frequency range. Thus, no frequency dependence could be determined. Due to measurement uncertainties and limitations of the test rigs, added linear damping and torsional damping could not be determined in either of the existing test rigs (lateral and torsional movement).