This project has been assigned by SwePart Transmissions AB. It is about calculation and dimensioning, of the elements in a cycloid stage of a speed reducer. Their idea is to use the results from this project and go into production of such reducer to cover another segment of the market. The company is interested in supplying transmissions for robust systems and for various industrial purposes, where large ratios of speed reduction are needed. The company has given the necessary input data for the model. They have also provided a real cyclo-drive reducer for further analyses. To obtain the dimensions and forming the geometry of the gears, some parts of Professor Ognyan Alipiev’s Phd work have been used. Professor Alipiev is head of “Theory of Mechanisms and Machines” department in University of Ruse “Angel Kunchev”, Bulgaria. For the determination of forces on the elements, models and drawings has been used Solidworks (SW) CAD software and SW simulation environment. The resultant calculation process can be used for designing the geometry and determination of the properties regarding the cycloid reducer. / Design of a Planetary-Cyclo-Drive Speed Reducer

A two-part project was used to study the idea of demonstration in architecture. The first was the design and fabrication of cycloidal drawing tools. The second was the design of another studio building for the College of Architecture and Urban Studies at Virginia Tech. First, the study of cycloidal lines became the catalyst for designing and fabricating cycloidal drawing tools. Drawing a cylcoid is a demonstration of its construction. There are no specialized tools available for drawing these types of lines, so several iterative generations of design were needed to refine the form of the tool and reach adequate accuracy. Second, an additional studio building for the College of Architecture and Urban Studies at Virginia Tech was designed. It was designed to be a place for the demonstration of craftsmanship. The building was placed adjacent to Cowgill Hall. The form of the building was explored through traditional tools of architectural design, namely drawings of plans, sections, elevations and details. For the best representation of this thesis, please refer to the book found in the Art and Architecture library. / Master of Architecture

The RV reducer (one tpye of cycloid reducer) which has two stage transmissions is widely used in manyfields of engineering. This project is going to design the first stage of the RV reducer, as well as therelated components. The details contain design of input shaft, planetary gears, output shaft, generalbearings and eccentric bearings. The fatigue analysis is mostly used in the calculation process becausethe fatigue failure happens frequently in such rotation machine. In the same time, the general bearingsdesign is based on SKF General Catalogue and the eccentric bearings design is supported by theChinese standard.

Made available in DSpace on 2014-06-11T19:24:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-04-25Bitstream added on 2014-06-13T18:52:57Z : No. of bitstreams: 1 coelho_ra_me_rcla.pdf: 5401836 bytes, checksum: 80bd8b943cf34df4138fa4c1dcc3291e (MD5) / O objetivo deste trabalho é analisar a forma como Huygens e os irmãos Bernoulli, propuseram e resolveram, respectivamente, os problemas do Isocronismo do Pêndulo (Tautócrona) e da Braquistócrona, Buscando, assim, contribuir para o entendimento dos métodos utilizados pelos eruditos para essas demonstrações. Trata-se de uma pesquisa de cunho histórico-analítico, centrada no século XVII, que fez-se uso de bibliografias que transcreviam os originais dos dois cientistas. Observou-se que para o sucesso da resolução dos problemas propostos, muitos conceitos matemáticos conhecidos até então foram usados, contudo os que mais deram suporte ao sucesso dos trabalhos em questão foram as teorias de Galileu e as contribuições de Mersenne. Tanto os Bernoulli quanto Huygens concluíram no final de seus trabalhos, que a curva procurada era uma Ciclóide. A Braquistócrona é um problema que faz parte de todo o desenvolvimento do Cálculo de Variações e o Isocronismo contribuiu para a construção de relógios de pêndulo mais precisos e dos marítimos. / The goal of this essay is analyzing the way how Huygens and the Bernoulli brothers, proposed and solved, respectively, the problems of the Pendulum Isocronism (tautochrone) and the brachistochrone. Intending, this way, to contribute for the understanding of the methods used for the erudites to these demonstrations. It is a research of a historical aspect, centered in the XVIII century, and it was made use of the bibliography which transcribed the originals of both scientists. It was observed that for the success of the resolution of the suggested problems, lots of mathematical concepts known at that time were used, however, the ones that had support to the success of the resolution of the suggested problems were Galileu´s theory and Mersenne´s contribution. As Bernoulli´s as Huygens concluded at the end of their works that the curve searched was a Cycloid. The Braquistócrona is a problem that is part of all the development of the Calculus of Variations and the Isocronism contributed to the construction of the most accurate pendulum clocks and the maritime ones.

Orientador: Marcos Vieira Teixeira / Banca: Sérgio Nobre / Banca: Iran Abreu Mendes / Resumo: O objetivo deste trabalho é analisar a forma como Huygens e os irmãos Bernoulli, propuseram e resolveram, respectivamente, os problemas do Isocronismo do Pêndulo (Tautócrona) e da Braquistócrona, Buscando, assim, contribuir para o entendimento dos métodos utilizados pelos eruditos para essas demonstrações. Trata-se de uma pesquisa de cunho histórico-analítico, centrada no século XVII, que fez-se uso de bibliografias que transcreviam os originais dos dois cientistas. Observou-se que para o sucesso da resolução dos problemas propostos, muitos conceitos matemáticos conhecidos até então foram usados, contudo os que mais deram suporte ao sucesso dos trabalhos em questão foram as teorias de Galileu e as contribuições de Mersenne. Tanto os Bernoulli quanto Huygens concluíram no final de seus trabalhos, que a curva procurada era uma Ciclóide. A Braquistócrona é um problema que faz parte de todo o desenvolvimento do Cálculo de Variações e o Isocronismo contribuiu para a construção de relógios de pêndulo mais precisos e dos marítimos. / Abstract: The goal of this essay is analyzing the way how Huygens and the Bernoulli brothers, proposed and solved, respectively, the problems of the Pendulum Isocronism (tautochrone) and the brachistochrone. Intending, this way, to contribute for the understanding of the methods used for the erudites to these demonstrations. It is a research of a historical aspect, centered in the XVIII century, and it was made use of the bibliography which transcribed the originals of both scientists. It was observed that for the success of the resolution of the suggested problems, lots of mathematical concepts known at that time were used, however, the ones that had support to the success of the resolution of the suggested problems were Galileu's theory and Mersenne's contribution. As Bernoulli's as Huygens concluded at the end of their works that the curve searched was a Cycloid. The Braquistócrona is a problem that is part of all the development of the Calculus of Variations and the Isocronism contributed to the construction of the most accurate pendulum clocks and the maritime ones. / Mestre

Monoamine oxidase (E.C.I.4.3.4) (MAO) oxidatively deaminates the biogenic amines normally present in the organism. The activities of the neurons utilizing these amines i.e. noradrenaline, dopamine and serotonin, are supposed to be involved in the pathogenesis of various psychiatric diseases. It is speculated that the MAO activity is changed as well as the monoaminergic activity in some psychiatric disorders. In the present thesis the MAO activity has been studied in brain tissue and in platelets in some psychiatric disorders. The result was as follows: MAO activities in different parts of the human brain seem to be highly intercorrelated in each individual. The brain MAO activity is also weakly correlated both to the concentration of 5-HT and of 5-HIAA, which may indicate that the MAO activity reflects the serotoninergic turnover in the brain. The MAO activity in brains from 15 suicides was compared to a control material of 20 individuals without known mental disorders, and it was found to be lower in the suicides in all 13 analysed brain parts. As eight of the patients had been chronic alcoholics, they were excluded and the remaining seven non-alcoholic suicides were tested as regards MAO activity by analysis of variance and still found to have significantly lower MAO activity than the controls. The eight chronic alcoholics in the suicide series had the most significantly (p<0.005) reduction of the MAO activity as compared to the control group. Rats were given chronic treatments with ethanol, either by 10 °/o ethanol as the only water supply or by exposition to ethanol vapor twice a day. In neither of these cases was the brain MAO activity changed as compared to control rats. The result supports the hypothesis that the low MAO activity found in alcoholic suicides most likely is related to a constitutional factor and not to a direct effect of the ethanol intake. Platelet MAO activity was found to be significantly reduced in human alcoholics as compared to matched controls. If samples were drawn from the alcoholic patients during their abstinence phase, there could be seen a transitory rise in the platelet MAO activity. This increased activity had its maximum after two weeks, and after four weeks the MAO activity had returned to the initial, low level. No difference as regards MAO activity, neither in brain tissue nor in platelets, could be registered when chronic schizophrenics were compared to matched controls. Reduced brain MAO activity was found in a group of patients diagnosed as cycloid psychoses when comparing the activity to controls or to the schizophrenic patients. The platelet MAO activity was also found to be lower in cycloid psychoses than in a group of unipolar affective psychoses, who repeatedly have been found not to differ from normals. These findings suggest that low MAO activities in brain and platelets reflect a phychic constitution in the individual making him more vulnerable for suicidal behaviour, ethanol abuse or cycloid psychosis. / digitalisering@umu.se

The thesis is focused on the properties of the selected plane curves of order higher than two and one transcendent curve. To each curve an overview of its properties which are then derived and described in detail is given. All curves are enriched with their images that are created in mathematical software GeoGebra. In addition, to these images the text links directly to GeoGebra are added, where some interesting features are described and demonstrated.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work aims at presenting methodological referrals able to make mathematics teaching more enjoyable and interactive. In this sense, the work that will be developed here will address the study of some special curves like the Agnesi Curve, the Epicycloid, the Hypocycloid and will focus in greater depth the study of Cycloid addressing its main properties with an emphasis on Tautochrone and Brachistochrone. All work performed in this study shows that mathematics can play an important role in the classroom, helping to develop the learning of other disciplines thanks to allied experimental practices to the development of interdisciplinary content. In the literature there is much talk on interdisciplinarity, but most texts do not show how it can be done, that is, little is done really. This paper describes the content and shows how to perform integrative activities that will improve the teaching of other sciences and allows students to develop other skills (in addition to mathematical reasoning). This work does not end here, it is the rst step to other studies that improve the teaching of mathematics, especially geometry. Introduce the content so that the curiosity of the student is instigated is a big step in the teaching of this discipline. This is the objective of this work, arouse the curiosity of those involved through experimental practices without so little put aside theoretical part. / Este trabalho tem como objetivo apresentar encaminhamentos metodológicos capazes de tornar o ensino da matemática mais prazeroso e interativo. Neste sentido o trabalho que será desenvolvido aqui abordará o estudo de algumas curvas especiais como a Curva de Agnesi, a Epiciclóide, a Hipociclóide e destacará com maior profundidade o estudo da Ciclóide abordando a suas principais propriedades com ênfase na Tautócrona e Braquistócrona. Todo trabalho realizado neste estudo mostra que a matemática pode assumir um papel importante na sala de aula, ajudando a desenvolver a aprendizagem de outras disciplinas graças às práticas experimentais aliadas ao desenvolvimento de conteúdos interdisciplinares. Na literatura fala-se muito em interdisciplinaridade, más na maioria dos textos não se mostra como é possível fazê-la, ou seja, pouco se faz realmente. Este trabalho descreve o conteúdo e mostra como realizar atividades integradoras que venham a melhorar o ensino de outras ciências e permite desenvolver outras habilidades (além do raciocínio matemático) no aluno. Este trabalho não se encerra aqui, ele é o primeiro passo para outros estudos que melhorem o ensino da matemática, em particular da geometria. Introduzir o conteúdo de forma que a curiosidade do aluno seja instigada já é um grande passo no ensino dessa disciplina. É este o objetivo deste trabalho, despertar a curiosidade dos envolvidos através das práticas experimentais sem tão pouco deixar de lado a parte teórica.

Today’s electric excavators uses standard hydraulics to control external tools. To increase the degree of freedom the excavator is equipped with a tiltrotator placed between arm and bucket. The combination of electronics and hydraulics proves to be less beneficial for the final operating time and shall thereby, if possible, be replaced with other options.  The study is conducted in purpose to present combinations of motors and drives which can apply and resist necessary forces. The solution replaces today’s hydraulic motor and worm drive powered by a hydraulic system existing of pump, hoses, and valves.  The transition can initially be motivated out of earlier studies which shows that electrification of hydraulic components has the potential to reduce the energy usage. In combination with this, excavators with an electric driveline becomes more and more popular which places increasing requirements on underlying systems.  Conduction of this work uses an analysis of earlier studies where identified components are evaluated out of geometric and characteristic features. Apart from this an analysis of strength in combination with required dimensions is made. The final solutions are compared with a hydraulic system to define potential energy savings.  Results shows two suitable solutions, one based on a DC motor and the other based on the patented technique for PMSM; the motors are combined with cycloid drives in two and one stages. The results shows that the solutions can be designed to apply necessary force as well as withstand external ones.

Legged robotics creates the demand for high torque compact actuators able to develop high instantaneous torque. Proprioceptive actuator design theory is a design theory that removes the need for a torque feedback device and relies on the stiffness in the leg for absorbing the high Ground Impact Forces created by walking locomotion. It utilizes a high torque density motor paired with a gearbox with a high gear ratio for torque multiplication. Previously work has been done to design a proprioceptive actuator design that utilizes a planetary gearbox to create a modular low-cost actuator for legged robotics. The purpose of this thesis is to design and analyze a proprioceptive actuator that utilizes a cycloidal gearbox design to test the feasibility of the gearbox design and look at the advantages it might bring over a planetary gearbox design. A cycloidal gearbox utilizes eccentric motion of cycloidal disks, made of epicycloids, to create a high gear ratio in a very limited space without having to rely on expensive gears for torque multiplication purposes. A prototype low-cost actuator was developed using a 2-disk cycloidal gearbox in its design. It was tested for wear life and torque control and was able to meet the torque and operation requirements of the Cal Poly legged robotics project. The design was also optimized to be made using low-cost additive manufacturing techniques rather than relying on conventional machining.