Estudou-se os mecanismos e tipos de desgaste atuantes nos machos de corte no processo de roscamento com velocidades comumente utilizadas na indústria e com alta velocidade de corte, de forma a avaliar a influência da velocidade de corte, do tipo de revestimento de ferramenta e da condição de lubri-refrigeração sobre o desempenho dos machos de corte. A qualidade da rosca usinada e a formação de cavaco também foram objetos de estudo. Mediram-se sinais de torque e de corrente ao longo da vida das ferramentas, avaliando as suas possibilidades como indicadores de desgaste. O roscamento de furos passantes M8x1,25 foi realizado com velocidades de corte de 30 ou 60 m/min em ferro fundido cinzento GG25 nas condições sem fluido de corte ou com mínima quantidade de lubrificante (MQL). Foram utilizados machos de corte de aço rápido comum e fabricados por metalurgia do pó revestidos, com TiAIN ou com TiCN. Os principais mecanismos de desgaste foram abrasão, adesão e difusão, enquanto o principal tipo de desgaste observado foi o de flanco. A adesão de material da peça sobre a ferramenta foi o principal fator determinante do final de vida dos machos de corte. A utilização de revestimento foi eficiente na minimização da adesão. Entretanto, o TiAIN foi melhor em termos de vida da ferramenta e o TiCN na redução do torque e na qualidade visual da rosca usinada. A técnica MQL propiciou melhorias na usinagem em comparação com a condição a seco, principalmente na redução do torque em machos de corte revestidos. Os sinais de torque e de corrente foram eficientes no acompanhamento do desgaste de flanco apenas nos machos de corte revestidos. Por outro lado, apenas os sinais de torque podem servir como indicativo das etapas do ciclo de roscamento. / The mechanisms and types of wear were studied in tools used in the tapping process performed with speeds commonly used in the industry and also with high cutting speed. It was evaluated the influence of cutting speed, type of tool coating and cooling/lubrication condition on the performance of the taps. The quality of the machined threads and the chip formation were also assessed. During the experiments, torque and current signals were measured, assessing the possibilities of using them as tool wear indicators. The tapping of through holes M8x1,25 was accomplished with cutting speeds of 30 or 60 m/min in gray cast iron GG25 in the conditions dry or with Minimal Quantity of Lubricant (MQL). Taps of plain High Speed Steel (HSS) and taps manufactured by powder metallurgy and coated (HSS-Co-PM, one with TiAIN and other with TiCN) were used. The main wear mechanisms observed were abrasion, adhesion and diffusion, while the principal type was the flank wear. The adhesion of workpiece material on the tools was the main decisive factor for the end of tool life. The tool coatings used were efficient in minimizing the adhesion. However, TiAIN was better in terms of tool life and TiCN in the reduction of torque and also led to a better visual quality on the machined threads. The MQL technique brought improvements to the machining in comparison to the dry cutting condition, mainly in the reduction of the torque in coated taps. The torque and current signals wereefficient in indicating the flank wear, only on coated taps. On the other hand, the torque signals can only be used as indicative of tapping cycle stages.

<p>The work presented in this thesis concernes two sorts of nanostructures: energetic-ion-impact-induced surface tracks and gas-deposited WO₃ nanoparticles. Our aims to characterise these nanostuctures and understand the physical principles behind their formation are of general interests for basic science as well as of the field of nanotechnology.</p><p>AFM studies of irradiated organic surfaces showed that individual ion impacts generate craters, most often accompanied by raised plastically deformed regions. Crater sizes were measured as a function of ion stopping power and incidence angle on various surfaces. Observed crater volumes were converted into estimates of total sputtering yields, which in turn were correlated with data from collector experiments. The observations were compared to predictions of theoretical sputtering models. The observed plastic deformations above grazing-incidence-ion penetration paths agree with predictions of the pressure pulse model. However, closer to the ion track, evaporative sputtering can occur.</p><p>AFM images of gas-deposited WO₃ nanoparticle-films indicated the formation of agglomerates. The size distribution of the agglomerates was measured to be log-normal, <i>i.e.</i> similar to the size distribution of the gas-phase nanoparticles forming the deposit. By simulations we could relatively well reproduce this observation. The agglomerates exhibited high thermal stability below 250°C when considering their size, implying that these porous films can be useful in applications involving elevated temperatures in the 250°C range. The appearance of the nanoparticles in the tapping-mode AFM images was sensitive to the free amplitude of the oscillating tip. We could show by model calculations that the high adhesion between the tip and the sample could account for some of these observations.</p>

The work presented in this thesis concernes two sorts of nanostructures: energetic-ion-impact-induced surface tracks and gas-deposited WO3 nanoparticles. Our aims to characterise these nanostuctures and understand the physical principles behind their formation are of general interests for basic science as well as of the field of nanotechnology. AFM studies of irradiated organic surfaces showed that individual ion impacts generate craters, most often accompanied by raised plastically deformed regions. Crater sizes were measured as a function of ion stopping power and incidence angle on various surfaces. Observed crater volumes were converted into estimates of total sputtering yields, which in turn were correlated with data from collector experiments. The observations were compared to predictions of theoretical sputtering models. The observed plastic deformations above grazing-incidence-ion penetration paths agree with predictions of the pressure pulse model. However, closer to the ion track, evaporative sputtering can occur. AFM images of gas-deposited WO3 nanoparticle-films indicated the formation of agglomerates. The size distribution of the agglomerates was measured to be log-normal, i.e. similar to the size distribution of the gas-phase nanoparticles forming the deposit. By simulations we could relatively well reproduce this observation. The agglomerates exhibited high thermal stability below 250°C when considering their size, implying that these porous films can be useful in applications involving elevated temperatures in the 250°C range. The appearance of the nanoparticles in the tapping-mode AFM images was sensitive to the free amplitude of the oscillating tip. We could show by model calculations that the high adhesion between the tip and the sample could account for some of these observations.

This dissertation focuses on quantitative subsurface and mechanical properties imaging potential of AFM probes. Extensive modeling of AFM probes are presented for thorough understanding of capabilities and limitations of current techniques, these models are verified by various experiments, and different methods are developed by utilizing force-sensing integrated read-out active tip (FIRAT), which is an active AFM probe with broad bandwidth. For quantitative subsurface imaging, a 3-D FEA model of AFM tip-sample contact is developed and this model can simulate AFM tip scan on nanoscale-sized buried structures. FIRAT probe, which is active and broadband, is utilized for interaction forces imaging during intermittent contact mode and mechanical characterization capability of this probe is investigated. It is shown that probe dynamics, stiffness, stiffness ambiguity, assumed contact mechanics, and noise are important parameters for the accuracy of mechanical properties imaging. An active tip control mechanism is introduced to limit contact forces during intermittent contact mode. In addition to these, a combined ultrasonic AFM and interaction forces imaging method is developed and modeled to solve the reduced elasticity measurement sensitivity on composite materials. This method is capable of imaging a broader range of elasticity on combination samples such as metal nanoparticles in polymers at nanoscale.

Estudou-se os mecanismos e tipos de desgaste atuantes nos machos de corte no processo de roscamento com velocidades comumente utilizadas na indústria e com alta velocidade de corte, de forma a avaliar a influência da velocidade de corte, do tipo de revestimento de ferramenta e da condição de lubri-refrigeração sobre o desempenho dos machos de corte. A qualidade da rosca usinada e a formação de cavaco também foram objetos de estudo. Mediram-se sinais de torque e de corrente ao longo da vida das ferramentas, avaliando as suas possibilidades como indicadores de desgaste. O roscamento de furos passantes M8x1,25 foi realizado com velocidades de corte de 30 ou 60 m/min em ferro fundido cinzento GG25 nas condições sem fluido de corte ou com mínima quantidade de lubrificante (MQL). Foram utilizados machos de corte de aço rápido comum e fabricados por metalurgia do pó revestidos, com TiAIN ou com TiCN. Os principais mecanismos de desgaste foram abrasão, adesão e difusão, enquanto o principal tipo de desgaste observado foi o de flanco. A adesão de material da peça sobre a ferramenta foi o principal fator determinante do final de vida dos machos de corte. A utilização de revestimento foi eficiente na minimização da adesão. Entretanto, o TiAIN foi melhor em termos de vida da ferramenta e o TiCN na redução do torque e na qualidade visual da rosca usinada. A técnica MQL propiciou melhorias na usinagem em comparação com a condição a seco, principalmente na redução do torque em machos de corte revestidos. Os sinais de torque e de corrente foram eficientes no acompanhamento do desgaste de flanco apenas nos machos de corte revestidos. Por outro lado, apenas os sinais de torque podem servir como indicativo das etapas do ciclo de roscamento. / The mechanisms and types of wear were studied in tools used in the tapping process performed with speeds commonly used in the industry and also with high cutting speed. It was evaluated the influence of cutting speed, type of tool coating and cooling/lubrication condition on the performance of the taps. The quality of the machined threads and the chip formation were also assessed. During the experiments, torque and current signals were measured, assessing the possibilities of using them as tool wear indicators. The tapping of through holes M8x1,25 was accomplished with cutting speeds of 30 or 60 m/min in gray cast iron GG25 in the conditions dry or with Minimal Quantity of Lubricant (MQL). Taps of plain High Speed Steel (HSS) and taps manufactured by powder metallurgy and coated (HSS-Co-PM, one with TiAIN and other with TiCN) were used. The main wear mechanisms observed were abrasion, adhesion and diffusion, while the principal type was the flank wear. The adhesion of workpiece material on the tools was the main decisive factor for the end of tool life. The tool coatings used were efficient in minimizing the adhesion. However, TiAIN was better in terms of tool life and TiCN in the reduction of torque and also led to a better visual quality on the machined threads. The MQL technique brought improvements to the machining in comparison to the dry cutting condition, mainly in the reduction of the torque in coated taps. The torque and current signals wereefficient in indicating the flank wear, only on coated taps. On the other hand, the torque signals can only be used as indicative of tapping cycle stages.

To understand more about the neural underpinnings for leading and following is the driving force behind this thesis. To do so, there is a need to study leading and following on a basic level. For study I, an fMRI study of neuronal reactivity during leading and following, a minimal model was developed to study leader and follower behavior in a standardized way. This model uses finger tapping of rhythms representing the core of the interactions during leading and following. Participants are invited to both lead and follow, and no expertise is expected. The status difference between the leader and follower is not a part of the model. Data collection is made in Japan, and most of the analyses are carried out in Sweden. In study II the Swedish Universities Scales of Personality is translated from Swedish to Japanese. Personality can be described as a crucial feature in a person’s social and emotional functioning; they are relatively stable over the course of a lifetime. Three dimensions representing personality facets probably relevant for leading and following are emotional stability, extraversion, and agreeableness. Study II resulted in SSPJ-11 with eleven reliable personality scales representing theses three facets relevant for leading and following. Study I presented an effective model to investigate leading and following during fMRI scanning. This model can be used with other designs for further brain imaging and behavior studies. From Study I, it became clear that the neuronal reactivation for leading and following largely overlap, with some specific differences in insular, temporal, and cerebellar reactivity. These results could be a first step towards a revealing the crucial components of neuro reactivations for leading and following.

No description available.

AABBSSTTRRAACCTT TTiittllee:: How to find the rate of border stress in the survival drill PPuurrppoossee:: Purpose of this master thesis is try to find acceptable instruments for determination of border stress in the survival drill. MMeetthhooddss:: This master thesis was worked up as empiric quantitative research observation type. We have tested 15 participants of course "Přesuny na sněhu a ledu" and 16 participants of course for survival instructors. For testing we used four motoric tests which were prepared to find actual stress of probands, psychological test OPTIM and in the second course hematologic research. RReessuullttss:: Measured values demonstrate possible connection in two motoric tests where the results are getting worse in border stress and in the extreme stress. In rest two tests there was not proved any connection between the results of tests and stress. KKeeyy wwoorrddss:: Actual stress, stress, soft motorics, equilibrium abilitiy, reaction ability, action ability, tapping rate. Vytvořeno pomocí Software602 Print2PDF 8. Tuto řádku odstraníte zakoupením licence a aktivací na http://www.software602.cz/

AABBSSTTRRAACCTT TTiittllee:: How to find the border stress in the survival drill PPuurrppoossee:: Purpose of this master thesis is to find acceptable instruments for determination of border stress in the survival drill. MMeetthhooddss:: This master thesis was worked up as empiric quantitative research observation type. We have tested 16 probands. For testing we used four motoric tests which were prepared to find actual stress of probands, psychological test OPTIM and in the second course hematologic research. RReessuullttss:: Measured values demonstrate possible connection in two motoric tests where the results are getting worse in border stress and in the extreme stress. In rest two tests there was not proved any connection between the results of tests and stress. KKeeyy wwoorrddss:: Actual stress, stress, soft motorics, equilibrium abilitiy, reaction ability, action ability, tapping rate.

A madeira foi largamente utilizada em edificações no período colonial brasileiro por sua abundância em variadas espécies e a facilidade de obtenção e adaptação aos fins previstos. Muitos destes imóveis ainda existem e abrangem a maior parte do patrimônio histórico e cultural de nossas cidades. Devido à degradação causada pelo tempo e a falta de manutenção adequada destes elementos estruturais, as edificações estão expostas ao risco de colapso. O objetivo deste trabalho foi sugerir um método de reabilitação parcial de vigas estruturais de madeira, pois se notou um problema recorrente nestes elementos em construções antigas pelo fato de acumularem umidade, serem alvos de patologias principalmente na parte superior. Para reabilitação empregamos madeiras de baixa densidade pela facilidade de compra desse material, baixo custo e principalmente por aderir muito bem a tratamento preservativo com CCB, o que garante que a estrutura estará protegida de novos ataques. Além das madeiras de baixa densidade tratadas, parafusos auto atarraxantes foram escolhidos para fazer a união entre as madeiras. Para os ensaios de flexão estática de 3 pontos foram adotados 4 diferentes tipos de parafusos variando o diâmetro e comprimento além disso, o número de parafusos inseridos nos corpos de prova também variou. Este estudo contém a análise de relação entre a quantidade de parafusos auto atarraxantes (que fazem a união das peças) e o produto de rigidez de peças mistas compostas de madeira referência (que simula a viga em estado de degradação) e madeira tratada (substituindo a porção degradada). Para a madeira referencia adotou-se Eucalipto (classe C30 de resistência) e Roxinho (classe C60) e, para madeira tratada adotou-se Pinus e Caxeta (de baixa densidade, ambas da classe C20). Análises estatísticas foram utilizadas para interpretação dos resultados obtidos em laboratório. Estas análises apontaram o crescimento do produto de rigidez das vigas mistas conforme a inserção de parafusos e a partir dai foi possível expressar em formulas a correlação dos dados. Utilizou-se o teste de Tukey para apontar o melhor tratamento para cada tipo de viga mista (Pinus e Eucalipto, Roxinho e Caxeta) além do melhor parafuso a se utilizar. / Wood was widely used in buildings in the Brazilian colonial period because of it is abundant in varied species and the ease of obtaining and adapting to intended purposes. Many of these properties still exist and cover most of historical and cultural heritage of Brazilian cities. Due to the degradation caused by the weather and lack of adequate maintenance of these structural elements, buildings are exposed to risk of collapse. The objective of this work was to suggest a method of partial rehabilitation of structural timber beams, since a recurrent problem was observed in these elements in old constructions due to accumulation of humidity, being targets of pathologies mainly in their upper part. For rehabilitation we use low density wood because of ease to purchasing this material, low cost and mainly for adhering very well to condom treatment with CCB, which ensures that the structure will be protected from further attacks. In addition to the treated low density woods, self-tapping screws were chosen to make union between woods. For tests, 4 different types of screws were used, varying diameter and length, and number of screws inserted in the specimens also varied. This study contains an analysis of relationship between the number of self-tapping screws (which make the joining of pieces) and the rigidity product of composite pieces of reference wood (which simulates beam in degraded state) and treated wood (replacing degraded portion). Eucalyptus (class C30 of resistance) and Roxinho (class C60) were used for reference wood, and Pinus and Caxeta (low density, both of class C20) were used for treated wood. Statistical analyzes were used to interpret results obtained in laboratory. These analyzes indicated growth of product of flexural stiffness according to insertion of screws and from this it was possible to express in formulas a correlation of data. Tukey test was used to indicate the best treatment for each type of mixed beam (Pinus and Eucalyptus, Roxinho and Caxeta) as well as the best screw to be used.