This thesis is about brass alloys with low lead levels for manufacturing of turned components destined for human consumption. Is it technically possible, economically viable and environmentally necessary to produce lead-free brass alloys? Turning tests and leaching tests has been carried out in low-lead brass. The result of the tests carried out show that it is technically possible to produce faucets in low-leaded brass, but since these alloys are harder and less ductile, it takes more power and more cooling when it is processed. There should be more reality-based tests in regular machines that belong in the line of manufacturing. Tests is needed to find out which tool materials, cutting angles, cooling, etc. which are needed to manufacture products with the right surface, dimensions, durability, etc. One thing that no one knows today is the lifetime of a faucet made of low-lead brass. If these faucet’s do not have a higher life than that made in CW 602 N, it is a major strain on nature to produce these in low-lead brass, then to maintain production of the faucets as it is today. No information has come from the Boverket of tougher requirements for lead content in brass. This makes it difficult to know how much effort that is needed to replace lead. A legal requirement or to lose market areas is otherwise a good motivation to move forward. / <p>http://www.du.se/md:Materialdesign är en civilingenjörsutbildning som ges i samarbete mellan Högskolan Dalarna (HDa) i Borlänge och Kungliga Tekniska Högskolan (KTH) i Stockholm. Det är KTH som utfärdar examensbeviset, även för dig som studerar i Borlänge.</p>

This thesis project was carried out at Sandvik Coromant in Västberga, Sweden with the purpose of developing a new laboratory test method for volumetric assessment of crater wear on inserts for steel turning. The test method was developed with the Sandvik Coromant´s existing crater wear measurement method as a starting point. Crater wear is currently measured as the projected area of exposed substrate, meaning where all coating layers have been removed. Based on earlier research on volume wear assessment, a focus variation microscope was selected to carry out 3D scans. To accurately measure the removed volume, an initial reference scan is required to capture individual variations existing on samples. The insert is then scanned after turning and compared with its reference. Factors affecting accuracy as well as possible improvements were identified as: Sample preparation, scan settings (resolution, quality) and data processing (alignment of scans, volume calculation etc.). Guiding alignment markers were created by laser ablation to help with alignment.  CloudCompare software was used to process the scanned 3D point clouds. A step by step routine was developed to ensure consistent results. The repeatability was assessed showing 8% standard deviation in volume for a shallow crater within the coating to 2% for a large crater worn into the substrate. The new method provides the possibility to measure wear while still inside the coating, which has been previously unavailable data. This enables measurement of the contribution of each specific coating layer on the wear resistance such as wear rate of a single layer instead of a combined wear rate for all layers. Detailed coating wear analysis is a valuable tool for development of optimized coatings. The developed wear measurement method was implemented on a case study which demonstrated the capabilities regarding its ability to resolve performance differences in experimental coatings. Additional wear parameters were used beside crater volume to support wear rate analysis and novel ways of representing volume wear parameters were presented.

O aumento da produtividade é sem dúvida um dos maiores desafios para a indústria de manufatura. Neste sentido, a vibração tem se apresentado ao longo das últimas décadas como um dos principais limitantes para a melhoria da produtividade, especialmente em operações de usinagem. Nos últimos anos muitas pesquisas foram conduzidas com o objetivo de suprimir ou minimizar os efeitos causados pelo fenômeno de vibrações regenerativas ou chatter. Este trabalho contribui propondo o desenvolvimento de um método para minimizar os efeitos da vibração em operações de torneamento por meio da variação dinâmica de parâmetros de corte relacionados com a área da seção de corte. No presente estudo optou-se pela operação de torneamento cilíndrico e a atuação dinâmica na profundidade de usinagem. Uma análise teórica e uma verificação das condições técnicas necessárias para a aplicação do método proposto são apresentadas. Além disso, simulações numéricas foram realizadas para verificação dos modelos analíticos e correlação com os ensaios práticos. Finalmente, utilizou-se o método em um processo de usinagem real e os resultados demonstram que é possível minimizar consideravelmente os efeitos do fenômeno de chatter variando dinamicamente a profundidade de usinagem sem afetar a qualidade final da peça usinada. / Improve productivity is with no doubts one of the greatest challenges for manufacturing industries nowadays. In that way, chatter vibrations has been arisen in last decades as a major limiting issue for productivity, especially on machining operations. In the last years many investigations has been carried out to suppress or minimize chatter vibrations effects on machining. In this work a development of a method to minimize chatters vibrations on turning operations by dynamically variation of cross section of the chip is proposed. Cylindrical turning operation was selected as the main target for this study and depth of cut as the parameter to be dynamically varied. A theoretical and essentials technical features analyses to apply the proposed method on a market machine tool are. Furthermore, numerical simulations were performed to validate and correlate analytical model to practical experiments. Finally, the proposed model was applied on real machining process and the results show that it is possible to substantially minimize the chatter vibration phenomenon by dynamically variation on depth of cut without affect the surface finishing.

Vários fatores, tais como custos, qualidade, flexibilidade e tempo de resposta, levam a vantagens competitivas. Nas indústrias do ramo metal mecânico, os fatores custos e qualidade estão intimamente ligados ao surgimento de novos materiais de difícil usinagem (cujos comportamentos ainda são desconhecidos), e como conseqüência o surgimento de novos e caros materiais de ferramentas juntamente com as exigências de alta produção, lotes variados, faixas de tolerâncias cada vez mais estreitas e baixos custos de produção, o que têm extrapolado os limites e habilidades de operadores de máquinas. Quanto aos fatores flexibilidade e tempo de resposta, as indústrias têm apontado uma grande necessidade de informações confiáveis sobre desempenho da produção e informações sobre parâmetros tecnológicos das máquinas-ferramenta. Sistemas de apontamentos manuais mostram-se deficientes, quanto à confiabilidade, velocidade de atualização, detecção de não conformidades e outros fatores prejudiciais à produção, além de gerarem redundância de trabalho na coleta e alimentação de bancos de dados. O sistema proposto contribui para a satisfação dessas necessidades, utilizando-se de tecnologias de comunicação e de aquisição de dados, que propicia o monitoramento e supervisão de processos de torneamento. Permite o monitoramento da qualidade dimensional e indiretamente do desgaste de ferramentas, e ainda o compartilhamento de informações de chão de fábrica, em tempo real, para qualquer localidade via intranet e/ou internet, auxiliando na integração do sistema de manufatura. / Several factors, such as costs, quality, flexibility and response time, influence the competitive advantages. In the metal working industries, the factors cost and quality are closely linked to the appearance of new materials difficult to machine (whose behaviors are still ignored). As a consequence, the appearance of new and expensive tool materials, together with the demands for high production, varied batches, range of tolerances more and more narrow and low production costs, what have been extrapolating the limits and abilities of operator’s machine. With regards to the factors flexibility and response time, industries have been pointing to a need for reliable information about production performance and about machine-tools technological parameters. Systems of manual appointments are subject to lack of reliability, up date, detection of non conformities and other factors affecting negatively the production system. Additionally, they can generate work redundancy in the acquisition and database feeding. The proposed system contributes to achieve that need using communication and data acquisition technologies, that allows the monitoring and supervision of turning processes. It allows the monitoring of the dimensional quality and indirectly tools wear, as well as sharing shop floor information, in real time, with any place through intranet and/or Internet, aiding the integration of the manufacturing system.

O aumento da produtividade é sem dúvida um dos maiores desafios para a indústria de manufatura. Neste sentido, a vibração tem se apresentado ao longo das últimas décadas como um dos principais limitantes para a melhoria da produtividade, especialmente em operações de usinagem. Nos últimos anos muitas pesquisas foram conduzidas com o objetivo de suprimir ou minimizar os efeitos causados pelo fenômeno de vibrações regenerativas ou chatter. Este trabalho contribui propondo o desenvolvimento de um método para minimizar os efeitos da vibração em operações de torneamento por meio da variação dinâmica de parâmetros de corte relacionados com a área da seção de corte. No presente estudo optou-se pela operação de torneamento cilíndrico e a atuação dinâmica na profundidade de usinagem. Uma análise teórica e uma verificação das condições técnicas necessárias para a aplicação do método proposto são apresentadas. Além disso, simulações numéricas foram realizadas para verificação dos modelos analíticos e correlação com os ensaios práticos. Finalmente, utilizou-se o método em um processo de usinagem real e os resultados demonstram que é possível minimizar consideravelmente os efeitos do fenômeno de chatter variando dinamicamente a profundidade de usinagem sem afetar a qualidade final da peça usinada. / Improve productivity is with no doubts one of the greatest challenges for manufacturing industries nowadays. In that way, chatter vibrations has been arisen in last decades as a major limiting issue for productivity, especially on machining operations. In the last years many investigations has been carried out to suppress or minimize chatter vibrations effects on machining. In this work a development of a method to minimize chatters vibrations on turning operations by dynamically variation of cross section of the chip is proposed. Cylindrical turning operation was selected as the main target for this study and depth of cut as the parameter to be dynamically varied. A theoretical and essentials technical features analyses to apply the proposed method on a market machine tool are. Furthermore, numerical simulations were performed to validate and correlate analytical model to practical experiments. Finally, the proposed model was applied on real machining process and the results show that it is possible to substantially minimize the chatter vibration phenomenon by dynamically variation on depth of cut without affect the surface finishing.

Chan, Ngai Shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 67-70). / Abstracts in English and Chinese. / Abstract --- p.I / 摘要 --- p.III / List of Figures --- p.VI / List of Tables --- p.VIII / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background Information --- p.2 / Chapter 1.1.1 --- Project Background --- p.2 / Chapter 1.1.2 --- Literature Review --- p.4 / Chapter 1.1.3 --- Background on Gear Hobbing --- p.10 / Chapter 1.1.4 --- Traditional gear hobbing machines --- p.12 / Chapter 2 --- Design and Testing of the MMT system --- p.15 / Chapter 2.1 --- Specifications of the MMT system --- p.16 / Chapter 2.1.1 --- Overall Configuration --- p.18 / Chapter 2.1.2 --- Linear Actuation --- p.18 / Chapter 2.1.3 --- Main Spindle Assembly --- p.19 / Chapter 2.1.4 --- Tool Plate Assembly --- p.20 / Chapter 2.1.5 --- Motion Control --- p.22 / Chapter 2.2 --- Main Features --- p.24 / Chapter 2.2.1 --- Mechanically Decoupled Gear Hobbing --- p.24 / Chapter 2.2.2 --- Single Setup for Non-planar Gears --- p.26 / Chapter 2.2.3 --- Quality Assurance by Computer Simulation --- p.27 / Chapter 2.3 --- Turning Test --- p.28 / Chapter 2.3.1 --- Experiment Results --- p.29 / Chapter 2.3.2 --- Tornos' Performance --- p.30 / Chapter 2.3.3 --- Estimation of Cutting Force and Workpiece Deflection --- p.32 / Chapter 2.4 --- Synchronization Test --- p.33 / Chapter 2.4.1 --- Experimental Results --- p.34 / Chapter 2.5 --- Gear Hobbing Test --- p.36 / Chapter 3 --- Diagnostic Tool: Gear Hobbing Simulation --- p.40 / Chapter 3.1 --- Simulation Model --- p.41 / Chapter 3.2 --- Simulations with Process Defects --- p.44 / Chapter 3.2.1 --- Asynchronous motion between tool and workpiece spindle --- p.44 / Chapter 3.2.2 --- Pitch error of the cutter hob --- p.45 / Chapter 3.2.3 --- Tool spindle run-out error --- p.47 / Chapter 3.2.4 --- Combination of process defects --- p.49 / Chapter 3.3 --- Experiment Validation --- p.50 / Chapter 4 --- Technical know-hows --- p.55 / Chapter 4.1 --- Premature Part Break-off --- p.55 / Chapter 4.2 --- Tool Alignment and Centering --- p.58 / Chapter 4.2.1 --- Two-turns Aligning Algorithm --- p.59 / Chapter 5 --- Conclusion and Future Work --- p.63 / References --- p.67 / Publication Record --- p.71 / Appendix --- p.72

Exclusive breastfeeding for at least six months and continued breastfeeding for the first year or two is promoted as the preferred method for feeding infants. In the United States, about 79% of infants are ever breastfed and less than 27% are breastfed through the first year (Centers for Disease Control and Prevention, 2014b). The purpose of this study was to understand the role of breastfeeding experiences and underlying factors that may facilitate the maintenance of breastfeeding one’s first child as well as the re-engagement in breastfeeding with one's second child. This dissertation includes two quantitative studies using secondary data and one qualitative study involving data specifically collected for this study. The quantitative studies used data from the Infant Feeding Practices Study II and the Year 6 Follow Up surveys. Findings indicate barriers in the early breastfeeding experience (pain, trouble with milk supply, and trouble with the baby’s suck or latch) are associated with less time spent in breastfeeding maintenance among first-time mothers and experiencing trouble with the first baby’s suck or latch is associated with non-initiation with one's second child. Conversely, as levels of perceived breastfeeding self-efficacy, opinion about the best way to feed a baby, and belief about breast milk increased, or became more pro-breastfeeding over time, time spent in breastfeeding maintenance among first-time mothers also increased. Those with a high level of response efficacy were also more likely to initiate breastfeeding with a second child. In the qualitative study, 28 first-time mothers who recently stopped breastfeeding and live in Iowa participated in semi-structured interviews. The objectives of this third study were to understand and describe first-time mothers’ experiences of infant feeding throughout the entire breastfeeding maintenance period, and explore how contextual factors may act as facilitators or barriers to breastfeeding maintenance by identifying common turning points. Turning points were defined as events or periods in time perceived as personally significant, that promoted a change, maintenance, or where a new meaning associated with the experience was acquired. Findings include seven turning points (breastfeeding problems, overcoming the unknown, recurring stressors, learning how to live life with the new baby, re-entering social roles, special occasions, and letting go) that were usually associated with stressful situations. The availability of intrapersonal (e.g., individual determination) and interpersonal (e.g., social support from others) coping resources at these turning points facilitated breastfeeding maintenance. The first study is significant in the longitudinal consideration of both experiences and changes in intrapersonal and interpersonal factors and how these changes relate to breastfeeding maintenance. The second study is significant with the focus on multiparous mothers and the effect of previous breastfeeding thoughts and experiences on breastfeeding initiation with a second child. The third study is unique in the identification of breastfeeding turning points that may lead to identifying opportune times and strategies for maintenance interventions. Findings from these studies have implications for intervention planning and future research. The synthesis of findings across the three studies suggests the early breastfeeding period is paramount to breastfeeding maintenance, along with the role of one’s social environment, particularly the perceived availability of social support to meet mothers' needs. Finally, findings from this dissertation can be used to improve social support provision and multi-level interventions targeting mothers’ most salient needs at the most opportune times.

It is difficult to think of any activity that does not require some degree of turning. Despite the prevalence of turning in daily activities and the challenge it poses to mobility-impaired individuals such as those with Parkinson’s disease, there is far less known about the multi-segmental control of turning than the control of standing and straight walking especially in elderly individuals and patient populations. The purpose of this thesis was to examine the coordination of body segment reorientation in healthy older adults and people with Parkinson’s disease (PD) during on-the-spot turns when standing and turns initiated when walking. The coordination of body segments was examined for small and large magnitude turns in both populations. PD participants were examined when “off” and “on” dopamine-replacement medication to determine the effects of medication on multi-segmental coordination when turning. The effect of walking velocity on the multi-segmental coordination of turning also was examined in healthy elderly participants for three different walking velocities. This research revealed differences in coordination patterns for standing versus walking turns and for healthy older adults versus persons with PD. Healthy older adults reorient their head, shoulder, and pelvis in unison, followed by mediolateral foot displacement, during standing turns. This coordination pattern was observed for both small and large turns. By contrast, turns initiated by healthy older adults while walking displayed a top-down temporal sequence similar to that reported for healthy young adults, i.e., the head turns first, followed by the shoulder and pelvis, and finally mediolateral displacement of the foot. This is a robust behavior which was not affected by the magnitude of the turn or walking velocity. PD participants (“off” and “on” medication) displayed temporal coordination patterns similar to age-matched healthy older adults for both standing and walking turns. However, PD participants (“off” and “on” medication) differed from healthy older adults with respect to the velocity and magnitude of reorientation of body segments, i.e., spatial parameters of coordination. The peak angular velocity of each body segment was significantly smaller for PD participants than the healthy older adults during both standing and walking turns; this was observed for both small and large magnitude turns. The magnitude of reorientation of each body segment was measured at the onset of mediolateral foot displacement; this measure revealed significantly smaller head and shoulder rotations for PD participants versus healthy older adults during standing turns, but not walking turns. Medication had no significant effect on the temporal or spatial parameters of body segment coordination during standing and walking turns. Medication increased the magnitude of head turn during the 90° standing turns; however, the magnitude of head turn remained smaller than that of healthy older adults. Multi-segmental coordination patterns differ for turns performed when standing (on-the-spot turn) versus when walking. The temporal parameters of these coordination patterns are not influenced by the magnitude of the turn or the velocity of walking and remain intact in Parkinson’s disease. Parkinson’s disease modifies the spatial parameters of coordination; reducing the velocity and early magnitude of reorientation of each body segment. These spatial parameters are not affected by dopaminergic medication.

BAKGRUND: Anorexia nervosa är latin och betyder ”nervös aptitlöshet” och det som präglar sjukdomen är självförvållad svält. Sjukdomen börjar vanligtvis med en bantning för att gå ned i vikt som spårar ur.  Anorexia nervosa förkommer hos cirka 1 % unga kvinnor, vilka också är de som drabbas i störst utsträckning. En rad allvarliga somatiska komplikationer kan ses till följd av sjukdomen som i svåra fall kan leda till döden.  Sjukdomen är individuell och det finns av den anledningen ingen självklar behandling. SYFTE: Syftet med studien är att beskriva kvinnors upplevelser av vändpunkter vid anorexia nervosa efter tillfrisknande. METOD: Fem självbiografier analyserades med hjälp av kvalitativ innehållsanalys. RESULTAT: Den kvalitativa innehållsanalysen resulterade i fyra kategorier som beskrev vändpunkter vid anorexia nervosa efter tillfrisknande: Sjukdomsinsikt, Motivation, Tillit samt Beslut. Tillfriskningsprocessen har visat sig vara individuell och olika kvinnor i studien har upplevt olika kombinationer av de nämnda vändpunkterna i tillfrisknandet. DISKUSSION: Sjukdomsinsikt har visat sig vara den viktigaste vändpunkten vid tillfrisknande i anorexia nervosa. Om en person inte vet om att hon eller han är sjuk, är det svårt att bli frisk. / BACKGROUND: Anorexia nervosa is latin for “nervous appetite lose” and what characterizes the disease is self-starvation. It usually starts with dieting to lose weight which loses control. Anorexia nervosa exists in about 1 % of all young women, and young women are also in the front of the disease. A number of serious somatic complications can follow the disease which in severe cases can cause death. The disease is individual and there is no obvious treatment. AIM: The aim of the study is to describe woman’s experiences of the turning-points in anorexia nervosa after recovery. METHOD: Five autobiographies were analyzed with qualitative content analysis. RESULTS: Qualitative analyses revealed four core categories who described the turning points of recovery in anorexia nervosa: Awareness of disease, Motivation, Trust and Decision. The recovery has proved to be individual and different women in the study have experienced different combinations of those turning-points for recovery. DISCUSSION: Awareness of disease provides to be the most essential turning-point for recovery in anorexia nervosa. If a person doesn’t know she or he is sick, there is no reason to get well.

It is difficult to think of any activity that does not require some degree of turning. Despite the prevalence of turning in daily activities and the challenge it poses to mobility-impaired individuals such as those with Parkinson’s disease, there is far less known about the multi-segmental control of turning than the control of standing and straight walking especially in elderly individuals and patient populations. The purpose of this thesis was to examine the coordination of body segment reorientation in healthy older adults and people with Parkinson’s disease (PD) during on-the-spot turns when standing and turns initiated when walking. The coordination of body segments was examined for small and large magnitude turns in both populations. PD participants were examined when “off” and “on” dopamine-replacement medication to determine the effects of medication on multi-segmental coordination when turning. The effect of walking velocity on the multi-segmental coordination of turning also was examined in healthy elderly participants for three different walking velocities. This research revealed differences in coordination patterns for standing versus walking turns and for healthy older adults versus persons with PD. Healthy older adults reorient their head, shoulder, and pelvis in unison, followed by mediolateral foot displacement, during standing turns. This coordination pattern was observed for both small and large turns. By contrast, turns initiated by healthy older adults while walking displayed a top-down temporal sequence similar to that reported for healthy young adults, i.e., the head turns first, followed by the shoulder and pelvis, and finally mediolateral displacement of the foot. This is a robust behavior which was not affected by the magnitude of the turn or walking velocity. PD participants (“off” and “on” medication) displayed temporal coordination patterns similar to age-matched healthy older adults for both standing and walking turns. However, PD participants (“off” and “on” medication) differed from healthy older adults with respect to the velocity and magnitude of reorientation of body segments, i.e., spatial parameters of coordination. The peak angular velocity of each body segment was significantly smaller for PD participants than the healthy older adults during both standing and walking turns; this was observed for both small and large magnitude turns. The magnitude of reorientation of each body segment was measured at the onset of mediolateral foot displacement; this measure revealed significantly smaller head and shoulder rotations for PD participants versus healthy older adults during standing turns, but not walking turns. Medication had no significant effect on the temporal or spatial parameters of body segment coordination during standing and walking turns. Medication increased the magnitude of head turn during the 90° standing turns; however, the magnitude of head turn remained smaller than that of healthy older adults. Multi-segmental coordination patterns differ for turns performed when standing (on-the-spot turn) versus when walking. The temporal parameters of these coordination patterns are not influenced by the magnitude of the turn or the velocity of walking and remain intact in Parkinson’s disease. Parkinson’s disease modifies the spatial parameters of coordination; reducing the velocity and early magnitude of reorientation of each body segment. These spatial parameters are not affected by dopaminergic medication.