Over the last few decades, miniaturization of the product became a necessity for many industries to achieve successful technological development, satisfy customer needs, and stay economically competitive in the market. Thus, many medical, aerospace, and electronic devices tend to decrease in size. Along with the strong demand for miniaturization, new cutting-edge micromanufacturing techniques are developing in order to produce microcomponents with a smooth surface finish and high dimensional accuracy. In the medical industry, some devices require manufacturing of fluidic microchannels on biocompatible materials for transportation of exact amount of medicine to a defined location. Often such microchannels must be manufactured to achieve a high aspect ratio, a submicron surface finish, and an anisotropic controlled profile. The fabrication of such channels on biocompatible materials still poses a challenge. This study developed micromanufacturing technique to produce the microchannels and satisfy all the requirements listed above. Computer controlled micromilling on a high speed machine system in minimum quantity lubrication was used to remove most materials and define a channel pattern. Microchannels were machined with ball end mills of diameters from Ø152μm to Ø198μm on NiTi alloy, 304 and 316L stainless steels. Assessment of microchannel was performed with optical microscopy, scanning electron microscopy, and white light interferometry. The theoretical surface roughness in ball end milling was derived using geometrical approach. The theoretical surface finish model was compared and validated with the experimental surface finish data. Meso- and macro-scale milling confirmed the validity of the model, but surface finish in micro-scale milling was measured to be a few orders of magnitude higher due to size effect and build-up edge. The build-up-edge was reduced when using AlTiN coated tools and milling in minimum quantity lubrication. The empirical surface roughness model obtained in this study shows the dependence of surface finish on chip load in micromilling. In order to further enhance the surface finish of milled microchannels additional finishing technique was identified. A separate study developed an effective electrochemical polishing technique to remove burrs and enhance surface finish of milled microchannels. When applying to 304, 316L stainless steel alloys and NiTi alloy, this hybrid technique can repeatedly produce microchannels with an average surface finish less than 100nm.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19236号 / 工博第4071号 / 新制||工||1628(附属図書館) / 32235 / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 西脇 眞二, 教授 松原 厚, 准教授 小森 雅晴 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Ultra precision single point diamond turning (SPDT) is a machining process used to produce optical grade surfaces in a wide range of materials. Aluminum is of primary interest as a workpiece material because it is easily diamond turnable, highly reflective and corrosion resistant. The cutting tool used is made from a single crystal diamond honed to a very sharp cutting edge. The machines used in this process are extremely precise and stiff. The nature of the cutting parameters used in SPDT changes the process physics substantially over conventional machining. The underlying reason relates to the relative size of the uncut chip thickness and the cutting edge radius of the tool in comparison to the grain size of the workpiece. When performing SPDT, there is a functional limit to the achievable surface finish. This is predominately due to material side flow and the opening up of material defects. Thus the machined surfaces have to undergo post processing operations like lapping or polishing, which increase cost and production time. Thus, the objective of this study was to improve the surface finish of the SPDT process to minimize the amount of post processing. The approach involved addressing the ratio between the tool cutting edge radius and the microstructure. Realizing the limitations associated with sharpening a diamond tool further, efforts have been made to mechanically or thermo-mechanically induce dislocations into the workpiece to refine the microstructure and in so doing enhance machinability. As dislocations act as a point of defect, it is observed that higher dislocation density offers less side flow and leads to better surface roughness. A special tool with a flat secondary edge was then developed to address the remaining side flow issue for planar surfaces. The combination of thermo-mechanically produced ultra fine grained material with the special tool provided a substantial reduction in surface roughness from values typically reported at 3nm [Roblee, 2007] Ra to 0.75nm R0 • In addition to this the use of the custom designed tool can improve the productivity associated with machining a flat face by a factor of one hundred times by allowing the feed rate to be increased while still achieving the desired surface finish. / Thesis / Doctor of Philosophy (PhD)

The safety of healthcare workers (HCW) has become a serious concern; therefore, a need for protection against bacterial penetration and transmission is realized. The purpose of this research is to examine whether antibacterial finishes can effectively reduce the presence of bacteria that have the potential for penetration and transmission on healthcare workers uniforms (HCWU). The specific objective of this research is to compare the antibacterial properties (i.e., bacterial reduction), two descriptive properties (i.e., fabric weight, fabric thickness), and one durability property (i.e., breaking strength loss due to abrasion) of a 65/35% polyester/cotton blend fabric treated with two commercially available antibacterial agents (i.e., 3-trimethoxysilylpropyldimethyloctadecyl ammonium chloride) or AEGIS Microbeshield, (AMS) and polyhexamethylene biguanide (PHMB) or Reputexâ · before laundering and after 5, 10, and 25 laundering cycles. The independent variables were the treatments (i.e., AMS, PHMB, no treatment) and the laundering cycles (i.e., 0, 5, 10, 25). The dependent variables were the four fabric properties: (a) antibacterial properties against Staphylococcus aureus (S. aureus) and Klebsiella pneumoniae (K. pneumoniae) bacteria, (b) fabric weight, (c) fabric thickness, and (d) breaking strength loss due to abrasion. Multiple Analysis of Variance (MANOVA) and Two-way Analysis of Variance (ANOVA) were used to examine the effects of the independent variables and their interaction on each dependent variable. The results showed PHMB treated specimens had a significantly higher log reduction against both S. aureus and K. pneumoniae before laundering and after 5, 10 and 25 laundering cycles than AMS treated specimens and the no treatment specimens. Initially, AMS had some reduction against S. aureus and K. pneumoniae before laundering; however after laundering, the reductions against both bacteria were diminished greatly. As expected, the no treatment specimen had no reduction against S. aureus or K. pneumoniae before and after laundering. The addition of PHMB and AMS increased the fabric weight of 65/35% polyester/cotton fabric and kept the fabric thickness throughout 25 laundering cycles. The untreated specimens became thicker after 25 laundering cycles. In addition, the breaking strength loss due to abrasion indicated that treatments had no effect on fabric strength. In conclusion, adding antibacterial agents do have some influence on bacterial reduction for both Gram-positive and Gram-negative bacteria as well as descriptive properties (i.e., fabric weight, fabric thickness). However, there was no influence on durability property (i.e., breaking strength loss due to abrasion). More studies are needed to test both agents on other types of fabrics such 100% cotton and nonwoven to incorporate more treated HCWU in the marketplace. / Ph. D.

This thesis topic was selected in order to explore a connection between a passion for the beauty of gemstones and craftsmanship of jewelry making to provide a metaphor for making beautiful architecture. The direction of the thesis made manifest connections and similarities between integrating art, craft and making beautiful jewel pieces and architectural spaces for a building devoted to housing the kinds of precious items that would be reflected in a city such as Washington DC. The appreciation of outstanding factors in gems and jewel making would be analogous to the precision, design and level of detail explored in an architectural thesis which aims to celebrate these relationships by applying them to the design for a museum of jewels and gemstones for Rock Creek Park in Washington DC. / Master of Architecture

Made available in DSpace on 2016-12-08T16:24:05Z (GMT). No. of bitstreams: 1 PGCA10MA033.pdf: 45133696 bytes, checksum: 53bbc7aa54baff70e775a4837351cdff (MD5) Previous issue date: 2010-08-11 / This paper presents the results of sanitary evaluation of pigs raised in a wean-to-finish system (WF). The experiment was carried out in the Midwestern region of Santa Catarina, from January to June 2009. During this period, eight herds were evaluated with a total of 3545 pigs, weaned with an average of 28 days of age and 8.22 kg of body weight. Data were collected through eight sanitary assessments, performed on days 0, 7, 14, 38, 69, 102, 137 and 143 after wean, which were called assessment 0, 1, 2, 3, 4, 5, 6 and 7 respectively . The assessment 0 consisted of an overview of the herds and facilities conditions at the time of the housing of the animals. The assessments 1, 2, 3, 4, 5 and 6 consisted of tutoring clinics, being evaluated rates of diarrhea, coughing and sneezing. The assessment 7 consisted in a slaughter evaluation for pulmonary, renal, hepatic and gastric lesions. Additional clinical evaluations, with achievement of necropsies followed by collection of samples for bacteriological and histopathological exams were made in animals when there were health problems in the respective herd. The rates of coughing and sneezing in the evaluated herds increased at the 13th and 18th weeks of age. The highest rate of diarrhea was observed during the nursery period in the first assessment, when Escherichia coli and Yersinia enterocolitica were isolated. During the growing and finishing period, Brachyspira sp. (114 days old), Salmonella sp. (105 days old) and Lawsonia intracelullaris (88 days old) were diagnosed. During the nursery period the most observed diseases was post-weaning diarrhea, and during the growing and finishing period the main disease was PCV2 assosiated disease. During the nursery period the mortality rate ranged from 0 to 1.08% and during the growing and finishing period it ranged from 1.82 to 6.72%. The main causes of mortality determined were circovirosis, Porcine intestinal distencion syndrome and septicemia, which accounted for 25.20%, 11.02% and 6.30% respectively. The rate of carcass condemnation by SIF (Federal Inspection) ranged from 1.02 to 6.71%, and the main cause was pleurisy (23.08 to 100%). The frequency of atrophic rhinitis and pneumonia ranged from 13 to 70% and 16.7 to 72.7% and the which index IRA and IPP ranged from 0.13 to 1.0 and 0.25 to 1.27, respectively. Renal lesions ranged from 33 to 50%, and nephritis was the most observed. The percentage of liver with white spots ranged from 4 to 37% of animals. Lesions in the pars esophageal of the stomach were observed in all the herds with frequency between 70 and 100%. The lesion grade 1 was the most frequently / O trabalho descreve a avaliação sanitária de suínos criados no sistema wean-to-finish (WF). O projeto foi realizado na região do Meio Oeste de Santa Catarina, no período de janeiro a junho de 2009. Foram acompanhadas oito granjas, com total de 3.545 suínos, criados no sistema wean-to-finish, alojados com média de 28 dias de idade e 8,22Kg de peso vivo. Os dados foram obtidos através de oito avaliações sanitárias, realizadas nos dias 0, 7, 14, 38, 69, 102, 137 e 143 de alojamento, sendo denominadas avaliações 0, 1, 2, 3, 4, 5, 6 e 7 respectivamente. A avaliação 0 consistiu em visualização geral dos suínos e condições das instalações no momento do alojamento. As avaliações 1, 2, 3, 4, 5 e 6 consistiram em monitorias clínicas, sendo avaliados índices de diarreia, tosse e espirro. A avaliação 7 consistiu em monitoria de abate para enfermidades respiratórias, renais, hepáticas e úlcera gástrica. Avaliações clínicas adicionais, com realizações de necropsias e/ou coleta de material para análises bacteriológicas e histopatológicas, foram efetuadas quando ocorreram problemas sanitários nas granjas. As frequências de tosse e espirro nas granjas avaliadas aumentaram na 13a e 18a semanas de idade. O maior índice de diarreia foi observado no período de creche, na primeira avaliação, sendo isolado Escherichia coli e Yersinia enterocolitica. Na fase de crescimento e terminação foi diagnosticado Brachyspira sp. (86 dias de alojamento/114 dias de idade), Salmonella sp. (77 dias de alojamento/105 dias de idade) e Lawsonia intracelullaris (60 dias de alojamento/88 dias de idade). No período de creche a doença mais observada foi a diarreia pós desmame e na fase de crescimento e terminação foi a circovirose. A mortalidade na fase de creche variou de 0,00% a 1,08% e na fase de crescimento e terminação de 1,82% a 6,72%, entre granjas. As principais causas de mortalidade determinadas foram a circovirose seguida de Síndrome da distensão intestinal suína (SDI) e septicemia, que representaram 25,20%, 11,02% e 6,30%, respectivamente. O desvio de carcaça pelo SIF variou de 1,02 a 6,71%, sendo a pleurisia a principal causa (23,08 a 100%). As frequências de rinite atrófica progressiva e pneumonia variaram de 13% a 70% e 16,7% a 72,7%, dos animais avaliados e os IRAP e IPP variaram de 0,13 a 1,0 e 0,25 a 1,27, respectivamente. As lesões renais variaram de 33 a 50%, sendo a nefrite a mais prevalente. A percentagem de fígado com manchas brancas variou de 4 a 37%. Em todas as granjas observou-se lesão na pars esofágica do estômago, com frequência de 70 a 100%, sendo a lesão de grau 1 a mais observada

Inconel 617 is a nickel-based superalloy whose properties include corrosion and oxidation resistance in high temperature environments. Due to their material properties, Inconel alloys are commonly used in aerospace applications where resistance to high pressure and temperature is required. These properties also cause the material to be hard to machine due to high temperatures in the cutting zone and its tendency to work harden. This paper focuses on improving the surface integrity and tool life for turning of Inconel 617 for use in next-generation nuclear applications. Various machining parameters are tested to improve the finish and tool life such as the feed rate, cutting speed, and depth of cut. While the machining of popular Inconel grades, such as Inconel 718, have been highly studied and understood, Inconel 617 lacks the knowledge base and research to define how the alloy behaves in machining and how it compares to other grades. Tests on tool coatings confirmed that commercially available coatings are durable enough to withstand the machining of this superalloy in finish turning and determined that AlTiN coatings provide the longest tool life. The investigations performed uncovered the relationship between cutting parameters and their influence on the surface integrity and tool life. MQL deposition was tested and found to be comparable and at times better than conventional flood coolant and may be considered a replacement for coolant after more improvement. This work details the knowledge and experimental procedure used to understand the machining of this superalloy. / Thesis / Master of Applied Science (MASc) / The purpose of this research is to develop an understanding of the machining of Inconel 617 for next-generation nuclear reactors. Canada’s plan to phase out coal-fired plants and deploy new nuclear reactors is contingent on being able to manufacture the necessary components. Inconel 617 is slated to be used in these high temperature, corrosive environments due to its high strength in elevated temperatures and its resistance to corrosion. However, since the material is a recent addition to the list of compatible materials, not much research has been performed on the manufacturing of this superalloy. Factors like cutting speed, coolant, and tooling were investigated and understood with the aim of improving the cost and time associated with manufacturing these nuclear grade components.

The purpose of this study was to develop a composite manufacturing process that would be able to deliver Class A surface finished products in the context of mould manufacturing methods. The problem required solving was to overcome the time needed to prepare Class A surfaces, by developing a composite manufacturing process that will deliver Class A surface finished products straight from the mould. The process was aimed at the entire development process, from mould and plug design up to the finished product. A literature study and a factory mould survey were conducted with a view to obtain the necessary insights into surface finishing and composite manufacturing. These surveys were followed by seven constructional tests which determined the most appropriate solutions for the proposed manufacturing processes. Test 1 was used to determine a quality finish standard for composites from the sanding grits used to finished composite surfaces versus surface roughness values used in other industries. The standard determined that a P800 finish has a roughness between 0.200 and 0.150 um and constitutes a Class A3 finish. P1000 to P1200 have a roughness between 0.150 um to 0.100 um and constitutes a Class A2 finish. Finally a P2000 and higher have a roughness of 0.100 um and lower and constitutes Class A1 surface finish. After the standard was set, the tests for finishing of the moulds, plugs and parts commenced. Test 2 was conducted on the CNC manufacturing of plugs out of Nuceron651 tooling board. Tool path parameters were varied in a matrix. The samples with the best surface finish value were cut with a step-over of 0.5 and feed of 800 mm/min. These parameters were found to be the most influential. Test 2 and 4 revealed that the plug surface finishing should commence with conventional 2K paint finishing, with a possibility of acrylic split surface. This process produced projected mould surfaces between 0.150 um and 0.200 um, which can be categorised as Class A-3. Test 5 and 6 determined methods for improving the mould surface quality and durability. It was established that the tooling gelcoat should be applied whilst being heated and backed with at least two layers of glass veil and a steady increase of GSM of structural glass fibres to prevent print-through. Test 3 determined that the mould corners could be strengthened with rovings pressed into the corner. It was also established that the moulds surfaces will require finishing after demoulding. The final moulds were manufactured from a fibreglass composite structure with tooling gelcoat surface. A number of guidelines and a set process were developed in order to produce moulds with a surface finish of average 0.9 um, equivalent to Class A1. Release agents were tested in Test 7, and the Loctite Frekote 770-NC release system was deemed appropriate for use with In Mould Coating (IMC) of 2K Paint. These elements were all synthesised into plug, mould and part manufacturing processes. The proposed processes were validated by the manufacturing of a JS instrument panel, which delivered a Class A2, 0.175 um, finish with IMC of 2K paint. With only a minor sanding of P3000 grit and polishing, the part was made into a Class A1 surface, measured at 0.63 um. The study proved that it is possible to produce Class A finished part with IMC. This method can provide a solution aimed at the elimination of P600 and lower finishing of composite parts manufactured with IMC. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

The purpose of this study was to develop a composite manufacturing process that would be able to deliver Class A surface finished products in the context of mould manufacturing methods. The problem required solving was to overcome the time needed to prepare Class A surfaces, by developing a composite manufacturing process that will deliver Class A surface finished products straight from the mould. The process was aimed at the entire development process, from mould and plug design up to the finished product. A literature study and a factory mould survey were conducted with a view to obtain the necessary insights into surface finishing and composite manufacturing. These surveys were followed by seven constructional tests which determined the most appropriate solutions for the proposed manufacturing processes. Test 1 was used to determine a quality finish standard for composites from the sanding grits used to finished composite surfaces versus surface roughness values used in other industries. The standard determined that a P800 finish has a roughness between 0.200 and 0.150 um and constitutes a Class A3 finish. P1000 to P1200 have a roughness between 0.150 um to 0.100 um and constitutes a Class A2 finish. Finally a P2000 and higher have a roughness of 0.100 um and lower and constitutes Class A1 surface finish. After the standard was set, the tests for finishing of the moulds, plugs and parts commenced. Test 2 was conducted on the CNC manufacturing of plugs out of Nuceron651 tooling board. Tool path parameters were varied in a matrix. The samples with the best surface finish value were cut with a step-over of 0.5 and feed of 800 mm/min. These parameters were found to be the most influential. Test 2 and 4 revealed that the plug surface finishing should commence with conventional 2K paint finishing, with a possibility of acrylic split surface. This process produced projected mould surfaces between 0.150 um and 0.200 um, which can be categorised as Class A-3. Test 5 and 6 determined methods for improving the mould surface quality and durability. It was established that the tooling gelcoat should be applied whilst being heated and backed with at least two layers of glass veil and a steady increase of GSM of structural glass fibres to prevent print-through. Test 3 determined that the mould corners could be strengthened with rovings pressed into the corner. It was also established that the moulds surfaces will require finishing after demoulding. The final moulds were manufactured from a fibreglass composite structure with tooling gelcoat surface. A number of guidelines and a set process were developed in order to produce moulds with a surface finish of average 0.9 um, equivalent to Class A1. Release agents were tested in Test 7, and the Loctite Frekote 770-NC release system was deemed appropriate for use with In Mould Coating (IMC) of 2K Paint. These elements were all synthesised into plug, mould and part manufacturing processes. The proposed processes were validated by the manufacturing of a JS instrument panel, which delivered a Class A2, 0.175 um, finish with IMC of 2K paint. With only a minor sanding of P3000 grit and polishing, the part was made into a Class A1 surface, measured at 0.63 um. The study proved that it is possible to produce Class A finished part with IMC. This method can provide a solution aimed at the elimination of P600 and lower finishing of composite parts manufactured with IMC. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

Alkyd emulsions are currently being developed for coating applications. These paints combine the technical advantages of alkyd polymers, which give coatings of a high gloss finish, with the environmental and health benefits of solvent-free systems. Nonetheless, the drying and film formation of these systems involve several steps, none of which is well understood yet. These include creaming or sedimentation, evaporation of the continuous water phase, coalescence of the alkyd droplets, a possible phase-inversion, and the oxidative cross-linking of the alkyd polymer to form a hard coating. In this thesis. Magnetic Resonance Microscopy is used to investigate the film formation of alkyd emulsion coatings. As the process is complex, studies on a different range of emulsions and related systems are performed to gain further insight into the different steps involved. A combination of Liquid State Microscopy, diffusometry and broad line imaging (Stray Field Magnetic Resonance Imaging) is employed, and it is shown that this combination provides results extremely rich in information. First, a study of the cream layer and the creaming dynamics of model bulk oil-in-water emulsions containing different concentrations of thickener is presented. The experimental data are compared to the predictions of a numerical model, and evidence is gained that the presence of the thickener induces flocculation according to a depletion mechanism. Then, the water evaporation from alkyd emulsion droplets is investigated and the water concentration across the droplet is modelled according to an original model based on lateral diffusion of water. There is no evidence from spectroscopy and diffusometry for phase-inversion during the drying of alkyd emulsion coatings. Finally the cross-linking of alkyds containing driers is found to be non-uniform across the film thickness.