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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Evaluation of Different Concepts for Pressed and Sintered Connecting Rods

Rehn, Mattias January 2019 (has links)
Connecting rod are found in most combustion engines and transmits thrust from the piston to the crankshaft. The connecting rod needs to withstand forces from the piston and inertia forces which results in axial tension, compression stresses and bending. Today the most common manufacturing techniques in automotive industry are drop-forging, die-casting and the Powder Metallurgy technique used is powder-forging. In this Master Thesis different connecting rod designs for a single press PM manufacturing process were created and evaluated as a part of Höganäs AB's Total Powder Metal Car project, TPMC. This paper will serve as a basis for future connecting rod projects at Höganäs AB when choosing a suitable connecting rod design. The main objective of this Master Thesis is to evaluate different designs in regards to the following: Buckling strength Fatigue life Manufacturing rating The study shows that there is evidence that a single pressed connecting rod is possible. No absolute answer of which design is the best is given in this paper since in depends on different parameters and application. For each parameter examined there are results presented and arguments for and against each design which can aid designers in future work. Suggestions of improvement on both the method and on the designs are presented in respect to the results. The improvements may potentially increase the fatigue life, buckling strength and improve manufacturability.
42

Sobre a técnica de Rod Drop em medidas de reatividade integral em bancos de controle e segurança de reatores / About the technique of Rod Drop in measures of rod worth in security and control rods of nuclear reactors

Stefani, Giovanni Laranjo de 12 April 2013 (has links)
Este trabalho apresenta um estudo sobre o efeito de sombreamento em detectores de nêutrons, quando estes são utilizados em medidas de reatividade com a técnica de rod drop. O sombreamento pode ser entendido como uma mudança na eciência dos detectores, quando esta é dada em nêutrons detectados/ssão ocorrida no reator, sendo mais evidente nos detectores mais próximos ao banco sendo inserido. O método de análise, fundamentalmente teórica, baseou-se em simulações do reator IPEN/MB-01 utilizando o código CITATION e o programa MCNP. Em ambos os casos, os resultados são estáticos, mostrando os uxos neutrônicos apenas em duas situações: antes da inserção do banco, e após sua inserção. A reatividade, neste caso, é obtida utilizandose a expressão derivada da técnica de source jerk. Em adição ao estudo teórico, os dados de um experimento de rod drop realizado no reator IPEN/MB-01 também foram utilizados. Neste caso, a reatividade foi obtida com o método de cinética inversa, já que os dados experimentais são constituídos de valores que variam no tempo. Em todos os casos, fatores de correção para o efeito de sombreamento são propostos. / This work presents a study on the eect of shading in neutron detectors, when used in measures of reactivity with the rod drop technique. Shading can be understood as a change in the eciency of the detectors, when it is given in detected neutrons / ssion occurred in the reactor, more evident in the detectors closest to the bank being inserted. The method of analysis was based on simulations of reactor IPEN/MB-01, using the code CITATION and MCNP program. In both cases, the results were static, showing Neutronic ows in only two situations: before insertion of the control rod and after insertion. The measure of reactivity in this case was achieved using the expression derived from the source jerk technique. In addition to theoretical study, data from a rod drop experiment conducted in the reactor IPEN/MB-01 were also used. In this case, the reactivity was obtained using inverse kinetic method, since experimental data were set of values that vary with time. In all cases, correction factors for the shadowing eect have been proposed.
43

Sobre a técnica de Rod Drop em medidas de reatividade integral em bancos de controle e segurança de reatores / About the technique of Rod Drop in measures of rod worth in security and control rods of nuclear reactors

Giovanni Laranjo de Stefani 12 April 2013 (has links)
Este trabalho apresenta um estudo sobre o efeito de sombreamento em detectores de nêutrons, quando estes são utilizados em medidas de reatividade com a técnica de rod drop. O sombreamento pode ser entendido como uma mudança na eciência dos detectores, quando esta é dada em nêutrons detectados/ssão ocorrida no reator, sendo mais evidente nos detectores mais próximos ao banco sendo inserido. O método de análise, fundamentalmente teórica, baseou-se em simulações do reator IPEN/MB-01 utilizando o código CITATION e o programa MCNP. Em ambos os casos, os resultados são estáticos, mostrando os uxos neutrônicos apenas em duas situações: antes da inserção do banco, e após sua inserção. A reatividade, neste caso, é obtida utilizandose a expressão derivada da técnica de source jerk. Em adição ao estudo teórico, os dados de um experimento de rod drop realizado no reator IPEN/MB-01 também foram utilizados. Neste caso, a reatividade foi obtida com o método de cinética inversa, já que os dados experimentais são constituídos de valores que variam no tempo. Em todos os casos, fatores de correção para o efeito de sombreamento são propostos. / This work presents a study on the eect of shading in neutron detectors, when used in measures of reactivity with the rod drop technique. Shading can be understood as a change in the eciency of the detectors, when it is given in detected neutrons / ssion occurred in the reactor, more evident in the detectors closest to the bank being inserted. The method of analysis was based on simulations of reactor IPEN/MB-01, using the code CITATION and MCNP program. In both cases, the results were static, showing Neutronic ows in only two situations: before insertion of the control rod and after insertion. The measure of reactivity in this case was achieved using the expression derived from the source jerk technique. In addition to theoretical study, data from a rod drop experiment conducted in the reactor IPEN/MB-01 were also used. In this case, the reactivity was obtained using inverse kinetic method, since experimental data were set of values that vary with time. In all cases, correction factors for the shadowing eect have been proposed.
44

Emilia Pardo Bazán ante el fin de siglo. Edición de “Eduardo Rod. El Pensador”

López Quintáns, Javier 25 September 2017 (has links)
El trabajo se ocupa del cambio de actitud literaria que en las últimas décadas del siglo XIX se advierte en la producción literaria de Emilia Pardo Bazán, desde una afinidad mitigada a los postulados del naturalismo hacia un enfoque en el que prima los derroteros marcados por un nuevo enfoque “espiritualista”. El cambio se advierte especialmente en la producción crítica de la autora, en la que se avanza en la reflexión sobre el cambio necesario de una a otra actitud. Emilia Pardo Bazán publica a finales del siglo XIX en La España Moderna un trabajo sobre la figura de Rod, representante de la nueva tendencia, que editamos. / The work deals with the literary change in the last decades of the nineteenth century (in the literary production of Emilia Pardo Bazán) from the Naturalism to the Spiritualism. Emilia Pardo Bazán published several works about Rod, representing the new trend. We publish “Escritores franceses contemporáneos: Rod”.
45

La performance des rôles de gros durs : un modèle de masculinité réinventé par Harvey Keitel et Rod Steiger / The performance of tough guy roles : a model of masculinity reinvented by Harvey Keitel and Rod Steiger

Flamenbaum, Beatrice 04 December 2015 (has links)
Le jeu de Harvey Keitel et de Rod Steiger réinventent les modèles de masculinité traditionnelle et les rôles de tough guys dans le cinéma américain. Ils permettent la déconstruction des notions-types du genre par l’ouverture de leur interprétation aux émotions, l’harmonie psycho-physique et la concentration sur les intentions et les circonstances. Keitel, acteur-icône du cinéma indépendant et découvreur de talents, se démarque dans un jeu marqué par l’intensité et l’exploration des aspects les plus sombres de l’humanité. Steiger excelle par la figuration de la solitude, de l’ambiguïté et de l’ambivalence, et figure des personnages tels que Napoléon, Mussolini ou Al Capone. Tous deux passés par l’interprétation américaine de la Méthode de Stanislavski, Keitel et Steiger s’affirment comme des acteurs-personnages, davantage que comme des stars. En effet, peu soucieux de leur image d’acteur, ils s’immergent dans la création de leurs personnages et figurent la relation complexe entre Moi social et Moi créateur. A travers l’analyse détaillée de leurs performances dans des genres différents, il semble que la comédie et les drames sentimentaux permettent aux acteurs de créer des performances adoucies, et de libérer leur imaginaire d’acteur-auteur. / Harvey Keitel and Rod Steiger’s performances reinvent the models of traditional masculinity and shed a new light on tough-guy roles in American film. Their emotional performances, their psycho-physical approach and their focus on objectives and circumstances open up new perspectives on gender and genre and lead to a deconstruction of the standard notions of genre. Keitel has become an iconic actor of independent cinema, by helping new directors and actors; and stands out with intense performances, which explore the darkest sides of humanity. Steiger excels in showing solitude, ambiguity and ambivalence, and acts various parts, such as Napoleon, Mussolini or Al Capone. Both actors study the American interpretation of Stanislavsky’s Method, and choose to become character-actors, rather than stars. Indeed, their inner acting primarily relies on the creation of a character, keeping in mind the complex relationship between Moi social and Moi créateur, and leaving aside their concern for their own image as actors. Through the detailed analysis of their performances in different genre movies, it comes to light that comedy, romance and drama allow the actors to free their performance from masculine stereotypes and to express their imagination as auteurs.
46

Isolating rod function in the human eye

Kelly, Jeremiah January 2013 (has links)
The first chapter explains the motivation for measuring rod function, in particular the rod’s dynamic recovery from a substantial bleach which results in so-called ‘rate limited’ recovery of sensitivity. The physiological processes that underpin the replenishment of the rod photopigment are described and discussed, and explain the way in which rod function can act as a marker for retinal health. Overall, this chapter explains why rod function is worthy of further investigation.Then follows a description of the experimental methods used in the study of rod function, presented in later chapters. The psychophysical procedures are described and a new method of dark adaptation measurement is presented. The key feature of this technique is a red background.Nonlinear mathematical models are used to describe the reduction in visual thresholds with time following a bleach. Chapter three describes the difficulties associated with numerical methods of nonlinear regression and presents a novel, multi start algorithm that extracts the parameters of interest from a model that adequately describes dark adaptation in the healthy normal subject.Chapter 4 verifies the algorithm presented in chapter 3, which is shown to be reliable and robust. A series of numerical experiments are performed to evaluate some of the characteristics of the algorithm’s performance.In chapter five, a series of experiments are presented to investigate the possible effect of a luminous background on dark adaptation (DA). The first experiment tests whether the rod system can detect a dim red background and the second, whether the rod thresh olds, when measured against light emitted by a red light emitting diode (LED), were linear. The third explores whether the background had any effect on the recovery of rod sensitivity. Finally, conventional contrast sensitivity is used to investigate the recovery from a photo bleach.A novel laboratory based apparatus was used to measure dark adaptation in a group of 36 subjects and the results of these measurements are presented in chapter six. The aim here was to see if the data collected were comparable with the dark adaptation data in the literature. These subjects were asked to make two visits so that an assessment of the test retest reliability of the method could be made. The method is shown to be reliable and capable of characterising the recovery of the visual system after a photo bleach.Although inherently flexible the analogue apparatus was prone to subject driven variability. Greater consistency of measurement was achieved using a digital device developed in partnership with an industry partner, Elektron (UK). This device, described in chapter seven provided fine control of many of the experimental parameters. It was used to measure the dark adaptation of a young healthy group of 21 people.This study uses new methodological approaches, both experimental and statistical, that are robust and reliable to facilitate investigation of rod function, and presents new findings about the early phase of rod sensitivity recovery.
47

Růstové charakteristiky termofilních mikroorganismů / Growth characteristics of thermophilic microorganisms

Kuchtová, Ludmila January 2010 (has links)
The aim of this work was focused on study of influence of cultivation conditions on growth of thermophilic bacteria Thermus aquaticus, Thermus scotoductus, Geobacillus thermodenitrificans and Geobacillus thermocatenulatus in cultivation medium recommended by Czech Collection of Microorganisms (CCM). The change of concentration of biomass during cultivation with various pH of media, cultivation temperature, agitation rate and with addition of glucose to medium during cultivation in Erlenmayer flasks was observed. Results served for determination of optimal growth conditions for each microorganism. After optimal growth conditions were obtained, cultivations in fermenter were performed. Growth curves were made from values of absorbance and dry weight of samples.
48

Letecký motor / Aircraft engine

Kalugin, Ivan January 2011 (has links)
This thesis is focused to design piston rods for aircraft petrol six-cylinder engine with 102 kW output power and project their form. Other part deals with analysis of balancing of arranging and fort control one of piston rod.
49

Novel mutations in NEB cause abnormal nebulin expression and markedly impaired muscle force generation in severe nemaline myopathy

Lawlor, Michael, Ottenheijm, Coen, Lehtokari, Vilma-Lotta, Cho, Kiyomi, Pelin, Katarina, Wallgren-Pettersson, Carina, Granzier, Henk, Beggs, Alan January 2011 (has links)
BACKGROUND:Nemaline myopathy (NM) is a congenital muscle disease associated with weakness and the presence of nemaline bodies (rods) in muscle fibers. Mutations in seven genes have been associated with NM, but the most commonly mutated gene is nebulin (NEB), which is thought to account for roughly 50% of cases.RESULTS:We describe two siblings with severe NM, arthrogryposis and neonatal death caused by two novel NEB mutations: a point mutation in intron 13 and a frameshift mutation in exon 81. Levels of detectable nebulin protein were significantly lower than those in normal control muscle biopsies or those from patients with less severe NM due to deletion of NEB exon 55. Mechanical studies of skinned myofibers revealed marked impairment of force development, with an increase in tension cost.CONCLUSIONS:Our findings demonstrate that the mechanical phenotype of severe NM is the consequence of mutations that severely reduce nebulin protein levels and suggest that the level of nebulin expression may correlate with the severity of disease.
50

A Field Monitor System of Rod-pumped Wells Based on GPRS

Zhaodong, Xing, Yanhong, Kou, Qishan, Zhang 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / To enhance the production management of the rod-pumped wells in the oil field, using a high performance single-chip as the processor, a field monitor system based on GPRS is researched and developed. In the paper the hardware design and software design are expatiated, the sampling frequency and determination rules for the running state are analyzed, the rational communication protocol is designed to ensure the reliable message transmission and reduce the communication fees. In the end the field monitor system is successfully implemented and verified in practice, part of data transmission result is illustrated.

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