Detta examensarbete handlar om att ta fram ett koncept på alternativa borstar och en bottenplåt i alternativt material för Weda W50. Anledningen till detta är att dagens borstar kräver ständig och noggrann rengöring för att inte haverera samt att bottenplåten orsakar elektrolytisk korrosion på resterande komponenter. För att kunna uppnå godtagbara resultat har metoder som idégenerering, materialsökning, modellering samt prototypframtagning använts. I genomförandefasen har tester utförts för att få en demonstration på hur de slutgiltiga komponenterna kommer att fungera i praktiken. Efter en avslutad genomförandefas blev resultatet fasta borstar med omdesignade länkarmar samt en bottenplåt i ABS-plast, vilket presenterats med både 3D-modellering och i fysisk komponent. Därmed har målen och syftet med detta examensarbete uppfyllts. / The purpose of this thesis is to examine and generate alternative concepts for the pool brushes and bottom plates used in the W50 underwater cleaning robot. The reason is that the current rotating brushes used on the W50 require thorough and consistent servicing to function as advertised, the other cause is that the bottom plate is produced in stainless steel which causes electrolytic corrosion on the surfaces of other components that are made in aluminum. Brainstorming, material research, 3D-modeling and prototyping were used to achieve tangible results. Several tests were conducted during the execution phase to give a live demonstration of how the final product is meant to perform. The results of the execution phase became fixed brushes for the W50, redesigned control arms and a bottom plate in ABS plastic. The results of this thesis work were demonstrated with the help of both 3D-modeling and physical models. Finally, the goals and purposes of this thesis were achieved.

The development of acrylonitrile-butadiene-styrene (ABS) resins for use in rotational molding would provide a medium performance material, thus opening doors to new markets for the rotational molding industry. Unfortunately, ABS resins have shown serious problems during the rotational molding process, namely discoloration, bridging, and poor impact strength. It is believed that these effects are due to degradation of the carbon-carbon double bond in the butadiene, through attack by either oxygen or heat. Previous efforts have shown some success in addressing these issues. However, additional improvements are necessary to make ABS resins commercially viable to rotational molders. This study, fourth in a series of similar projects conducted though Brigham Young University, was focused on remediation of the ABS difficulties via two different approaches. First, a survey of several additives was performed with the intent of investigating four different strategies: increased protection from oxygen, decreased butadiene concentration, increased butadiene concentration, and promotion of flow. The best formulation was achieved when 15 wt % of a benzoate ester (XP-2280 available though ChemPoint) was blended into MAGNUM 342 EZ, an ABS resin (The Dow Chemical Company). This formulation showed the best balance between increased impact strength and improvement of cosmetic properties. Second, optimization of several rotational molding processing parameters was executed. These included particle size distribution of the resin, drying of the resin, internal mold atmosphere, and oven temperature. It was found that using coarse particle sizes (ground at 20-mesh rather than the industry standard of 35-mesh) increased the impact strength by about 19%. None of the other parameters proved to have a significant effect upon the system, except for the use of a nitrogen atmosphere, which lowered the impact strength. Final properties testing of this best formulation at the optimal processing conditions showed increased impact strength from 2 ft-lbs (the previous best value) to 8 ft-lbs. There was also a marginal decrease in surface hardness (95 to 78 on the Rockwell R scale) and yield tensile strength (3,900 psi to 3,300 psi). Larger differences were observed in flexural modulus (200,000 psi to 110,000 psi) and heat distortion temperature (95°C to 61°C). Therefore, these formulation and processing changes show a trade-off where stiffness and thermal stability (i.e. flexural modulus and heat distortion temperature) can be sacrificed for an increase in toughness and aesthetics, made manifest by increased impact strength, elimination of bridging, and eradication of discoloration.

An attempt was made to construct an ABS system that would both lock the wheel and release the brakes. The system would be mounted on a bicycle with v-brakes. It would then be tested if it could decrease the braking distance and if the system would respond fast enough. A literature study was made to learn what was needed for such a project. After many attempts of using re-purposed components an ABS system would eventually be built with a new stepper motor, and it was strong enough to lock the back wheels. Unfortunately the system could not be as thoroughly tested as expected, where only the reaction time of the system could be tested and not the braking distance due to a motor driver failure prior to the tests taking place. Due to shipping times and our budget and time constraints, further testing could not be done. / Ett försök att bygga ett ABS system som både låser hjulet samt släpper på bromsen gjordes. Systemet skulle kunna monteras på en cykel med fälgbromsar. Systemet skulle testas genom att mäta skillnaden i bromssträcka samt om reaktionstiden var snabb nog. En litteraturstudie gjordes för att få tillräcklig kunskap om vad som krävdes för ett sådant projekt. Efter många försök med att använda olika återanvända komponenter kunde ett ABS system till slut konstrueras med hjälp av en ny stegmotor, som var stark nog för att låsa bakhjulet. Tyvärr kunde bara systemets reaktionstid testas och inte bromssträckans förändring. Detta berodde på en motordrivare slutade fungera. På grund av frakttider och en fast budget samt en tidsbegränsning, kunde inte ytterligare tester genomföras.

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Os resíduos eletroeletrônicos vêm aumentando no mundo e contribuem com a escassez de recursos naturais e com a ocupação de espaços em aterros que estão esgotando sua capacidade de disposição de resíduos. Uma alternativa é a reciclagem dos resíduos eletroeletrônicos e para viabilizar o processo, é importante conhecer a composição dos materiais para direcionar tecnologias e conseguir sua recuperação. Esses resíduos possuem uma diversidade de plásticos que, ao serem reciclados, garantem o seu reaproveitamento como fonte de matéria prima para a produção de materiais poliméricos. O ABS (copolímero: Acrilonitrila Butadieno Estireno) e o HIPS (Poliestireno de Alto Impacto) são dois tipos de polímeros muito utilizados nas indústrias de eletroeletrônicos. O objetivo deste trabalho é estudar a separação do ABS e do HIPS para a reciclagem, utilizando as Técnicas de Tratamento de Minérios como a separação por flotação. Para a separação dos polímeros, os resíduos eletroeletrônicos foram desmantelados manualmente e os componentes plásticos foram separados por tipo e cor. Os plásticos separados, foram cominuídos no moinho de facas e classificados por meio do ensaio granulométrico. Os ensaios de flotação foram conduzidos em uma coluna de vidro, utilizando se de soluções de álcool etílico e de ácido acético em diferentes concentrações. As soluções atuaram como agentes hidrofilizantes de superfície, permitindo a separação desses polímeros. Na flotação com o etanol, os experimentos mostraram os melhores resultados na concentração de 20% em massa, com a pureza de HIPS de 96% e do ABS de 98%. Na flotação com o ácido acético, os ensaios mostraram os melhores resultados na concentração de 40% em massa, com a pureza do ABS de 96% e de HIPS de 86%.A flotação com 20% de concentração de etanol apresentou melhor eficácia na recuperação e na pureza do HIPS e do ABS em relação à flotação com 40% de ácido acético. / The speed in which new technologies are being developed stimulates the rapid obsolescence of electronic equipment. Hence electronic waste grows at high rates all over the world and has become an environmental issue due to its accumulation in landfills. In order to reduce these environmental impacts, a feasible solution is recycling. Recycled allows its reuse as a source of raw material for the production of polymeric materials as well as for energy generation. ABS (copolymer: Acrylonitrile Butadiene Styrene) and HIPS (High Impact Polystyrene) are the most common polymers used in the electro electronic industry. The aim of this work is to study the separation of ABS and HIPS using the froth flotation technique. Froth flotation is a process of separating the solid particles through differences in their surface characteristics. The reason for using this technique is that gravimetric methods are unlikely to produce good results due to the similar specific weights of both materials. Froth flotation also is difficult as both plastics are water repellent (hydrophobic). The samples were manually dismantled, with plastic components separated by type and color. After that, comminution was performed in a knife mill and grain sizes separated in screen. The flotation tests were conducted in a glass column, using ethyl alcohol and acetic acid solutions with different concentrations. These solutions were used to increase the hydrophilic characteristics in the surface of ABS, and to make possible the separation of these polymers. When floating with ethanol, the experiments showed the best results at a concentration of 20% in weight, with purity levels of 96% of HIPS and 98% of ABS. When floating with acetic acid, the tests showed the best results at the concentration of 40% in weight, with purity levels of 96% of ABS and 86% of HIPS.The flotation with 20% in weight of ethanol concentration showed better results in recovery and purity of HIPS and ABS in comparison to the 40% acetic acid.

Os resíduos eletroeletrônicos vêm aumentando no mundo e contribuem com a escassez de recursos naturais e com a ocupação de espaços em aterros que estão esgotando sua capacidade de disposição de resíduos. Uma alternativa é a reciclagem dos resíduos eletroeletrônicos e para viabilizar o processo, é importante conhecer a composição dos materiais para direcionar tecnologias e conseguir sua recuperação. Esses resíduos possuem uma diversidade de plásticos que, ao serem reciclados, garantem o seu reaproveitamento como fonte de matéria prima para a produção de materiais poliméricos. O ABS (copolímero: Acrilonitrila Butadieno Estireno) e o HIPS (Poliestireno de Alto Impacto) são dois tipos de polímeros muito utilizados nas indústrias de eletroeletrônicos. O objetivo deste trabalho é estudar a separação do ABS e do HIPS para a reciclagem, utilizando as Técnicas de Tratamento de Minérios como a separação por flotação. Para a separação dos polímeros, os resíduos eletroeletrônicos foram desmantelados manualmente e os componentes plásticos foram separados por tipo e cor. Os plásticos separados, foram cominuídos no moinho de facas e classificados por meio do ensaio granulométrico. Os ensaios de flotação foram conduzidos em uma coluna de vidro, utilizando se de soluções de álcool etílico e de ácido acético em diferentes concentrações. As soluções atuaram como agentes hidrofilizantes de superfície, permitindo a separação desses polímeros. Na flotação com o etanol, os experimentos mostraram os melhores resultados na concentração de 20% em massa, com a pureza de HIPS de 96% e do ABS de 98%. Na flotação com o ácido acético, os ensaios mostraram os melhores resultados na concentração de 40% em massa, com a pureza do ABS de 96% e de HIPS de 86%.A flotação com 20% de concentração de etanol apresentou melhor eficácia na recuperação e na pureza do HIPS e do ABS em relação à flotação com 40% de ácido acético. / The speed in which new technologies are being developed stimulates the rapid obsolescence of electronic equipment. Hence electronic waste grows at high rates all over the world and has become an environmental issue due to its accumulation in landfills. In order to reduce these environmental impacts, a feasible solution is recycling. Recycled allows its reuse as a source of raw material for the production of polymeric materials as well as for energy generation. ABS (copolymer: Acrylonitrile Butadiene Styrene) and HIPS (High Impact Polystyrene) are the most common polymers used in the electro electronic industry. The aim of this work is to study the separation of ABS and HIPS using the froth flotation technique. Froth flotation is a process of separating the solid particles through differences in their surface characteristics. The reason for using this technique is that gravimetric methods are unlikely to produce good results due to the similar specific weights of both materials. Froth flotation also is difficult as both plastics are water repellent (hydrophobic). The samples were manually dismantled, with plastic components separated by type and color. After that, comminution was performed in a knife mill and grain sizes separated in screen. The flotation tests were conducted in a glass column, using ethyl alcohol and acetic acid solutions with different concentrations. These solutions were used to increase the hydrophilic characteristics in the surface of ABS, and to make possible the separation of these polymers. When floating with ethanol, the experiments showed the best results at a concentration of 20% in weight, with purity levels of 96% of HIPS and 98% of ABS. When floating with acetic acid, the tests showed the best results at the concentration of 40% in weight, with purity levels of 96% of ABS and 86% of HIPS.The flotation with 20% in weight of ethanol concentration showed better results in recovery and purity of HIPS and ABS in comparison to the 40% acetic acid.

Jowett and O'Donnell observe that 'there is a clear revival of interest in the important role of propaganda in many aspects of modern life, not necessarily related to international intrigue or military campaigns' (1992, p. xi). This thesis has examined the 1991 Census communication campaign (ABS 1991a) for evidence of propaganda intentions and strategies. Propaganda is clearly a pejorative term and its application to a particular campaign could imply a covert attempt at manipulation by the authority behind the campaign�the Australian Bureau of Statistics (ABS). As the author was responsible for the development, implementation and evaluation of the 1991 Census communication campaign and had privileged access to a range of sources, a reader might expect detailed references to internal files which reveal conscious decision-making to mount a propaganda campaign. This is not the case. An analysis of the 150 working files associated with the campaign revealed no support for such a hypothesis; there was no evidence of decision-making with the intent of implementing propaganda strategies. Similarly, during interviews with senior ABS managers, these managers categorically rejected the notion that the Bureau conducted a propaganda campaign and pointed to the fact that all procedures were cleared through both the Federal Parliament and the Privacy Commissioner. The hypothesis explored by this thesis is that despite this lack of conscious direction, propaganda processes are evident in the way the ABS conducted the communication campaign for the 1991 Census. The perspective of the thesis is closely aligned to that of Altheide and Johnson who locate propaganda as the bridge between 'organisational image and reality' (1980, p. 4). Altheide and Johnson regard propaganda as an insidious phenomena based on impression-management through the 'rigorous pursuit of scientifically valid procedures and standards' (1980, p. 229). The end result of this impression-management is that certain 'facts' are presented to the exclusion of all others. This thesis argues that impression-management strategies are evident in the way the ABS conducted the communication campaign for the 1991 Census. The processes of impression-management are subtle and do not reside in such sources as internal files. The process operates through the internalised ethos and corporate values inculcated in the minds of senior staff within the Bureau and is best conceptualised as a mindset, reflected in outcomes. I have used the term mindset to cover the process of converting abstract values into specific guides for action�fora discussion of this process see Hall (1977, pp. 69 - 83). This mindset is well-illustrated by the issue of compulsion�the obligation to complete a census form. At one level the ABS procedures are impeccable: cleared through the federal parliament and the Privacy Commissioner�and it is this form of discourse that is documented in internal files. The procedures do not, however, enable respondents to make an informed decision about whether the census is compulsory and about the ramifications for non-compliance. The mindset operating here is based on the value of the census to the ABS�the census is good for the ABS�it generates revenue and legitimises the role of the organisation. The thesis presents data which establishes that there is a significant gap between the organisational image of the census (in the corporate mind of the ABS) and that perceived by householders. The mindset of the ABS is clearly evident in the procedures adopted on this issue. The main finding of this thesis is that many of the processes underlying the development of the 1991 Census communication campaign were subtle environmental influences. These reflected the internal dynamics of the ABS, and its ability as an institution to control the communication environment through addressing the needs of other major organisations, such as the media, and the release of selective information to specific target audiences. In this context, institutional dynamics, more than decisions by individual managers, influenced the conduct of the campaign. The process of propaganda, therefore, is implicit in the 1991 Census rather than explicit�a distinction, in terms of process, drawn by Pearlin and Rosenberg (1954) in their examination of propaganda techniques in institutional advertising. It should also be acknowledged that whilst the author did have privileged access to information, there is no information contained in this thesis that would not be publicly available. The majority of primary sources are reports published by the ABS or papers delivered by Bureau staff at a range of fora. Permission was sought from the ABS for assistance in obtaining access to information and this was readily granted.

Polycarbonate (PC) is a glassy engineering thermoplastic that has been used for decades because of its superior mechanical properties such as high toughness and stiffness, and for its general thermal stability. However, the industrial demand for higher performance polymers with faster processing times has caused PC to be gradually replaced by different engineered polymer blends, such as polycarbonate/acyrlonitrile-butadiene-styrene (PC/ABS). Blends combine the advantages of the individual components but because they are a relatively new class of materials, their time-dependent behaviour is less well understood. The goal of the present work is to characterize two primary time-dependent processes in a commercial 75:25 PC:ABS blend that are known to affect the long-term mechanical properties of the individual components. The first is physical aging which is a result of non-equilibrium fast cooling of glassy or amorphous polymers. Physical aging is associated with structural relaxation due to enthalpic and volumetric recovery. The second process is hygrothermal conditioning which is the combined application of thermal aging and moisture absorption. Three sets of characterization tests were conducted using Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared spectroscopy (FTIR). The enthalpic relaxation results determined from DSC data for aging at nine different combinations of time and temperature showed that aging experiments are best conducted at temperatures between 80 and 90°C. This range is below the glass temperature of the ABS component. The activation energy for enthalpic relaxation for the unaged blend was found to fall between energies for PC and ABS relaxations, but not according to the rule-of-mixtures. The present study attempted to adopt the Tool–Narayanaswamy-Moynihan (TNM) phenomenological model to predict relaxation kinetics but was found to be complicated by multiple endothermic peaks. It was then concluded that the TNM model, although very useful for single polymer systems, is unsuitable for blends. A semi-empirical model was applied instead to fit the experimental data which provided a reasonable estimate of the relaxation behaviour. Aging at 80°C for the period investigated did not reach equilibrium and it is expected that aging times of upwards of 2 years will be necessary to minimize the errors associated with the data fitting to provide a better fit of the model. The FTIR studies revealed that thermal aging at 80°C in dry atmosphere results in oxidation of the butadiene component. However, the addition of moisture to the aging process appears to prevent, or at least impede, oxidation from occurring. The presence of moisture seems to trigger hydrogen bonding, which saturates regardless of the moisture content after approximately 80 days. The initial rate of moisture diffusion in PC/ABS appeared to depend predominantly on temperature while the ambient moisture concentration tends to only affect the final equilibrium content in the blend.

Polycarbonate (PC) is a glassy engineering thermoplastic that has been used for decades because of its superior mechanical properties such as high toughness and stiffness, and for its general thermal stability. However, the industrial demand for higher performance polymers with faster processing times has caused PC to be gradually replaced by different engineered polymer blends, such as polycarbonate/acyrlonitrile-butadiene-styrene (PC/ABS). Blends combine the advantages of the individual components but because they are a relatively new class of materials, their time-dependent behaviour is less well understood. The goal of the present work is to characterize two primary time-dependent processes in a commercial 75:25 PC:ABS blend that are known to affect the long-term mechanical properties of the individual components. The first is physical aging which is a result of non-equilibrium fast cooling of glassy or amorphous polymers. Physical aging is associated with structural relaxation due to enthalpic and volumetric recovery. The second process is hygrothermal conditioning which is the combined application of thermal aging and moisture absorption. Three sets of characterization tests were conducted using Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared spectroscopy (FTIR). The enthalpic relaxation results determined from DSC data for aging at nine different combinations of time and temperature showed that aging experiments are best conducted at temperatures between 80 and 90°C. This range is below the glass temperature of the ABS component. The activation energy for enthalpic relaxation for the unaged blend was found to fall between energies for PC and ABS relaxations, but not according to the rule-of-mixtures. The present study attempted to adopt the Tool–Narayanaswamy-Moynihan (TNM) phenomenological model to predict relaxation kinetics but was found to be complicated by multiple endothermic peaks. It was then concluded that the TNM model, although very useful for single polymer systems, is unsuitable for blends. A semi-empirical model was applied instead to fit the experimental data which provided a reasonable estimate of the relaxation behaviour. Aging at 80°C for the period investigated did not reach equilibrium and it is expected that aging times of upwards of 2 years will be necessary to minimize the errors associated with the data fitting to provide a better fit of the model. The FTIR studies revealed that thermal aging at 80°C in dry atmosphere results in oxidation of the butadiene component. However, the addition of moisture to the aging process appears to prevent, or at least impede, oxidation from occurring. The presence of moisture seems to trigger hydrogen bonding, which saturates regardless of the moisture content after approximately 80 days. The initial rate of moisture diffusion in PC/ABS appeared to depend predominantly on temperature while the ambient moisture concentration tends to only affect the final equilibrium content in the blend.

This thesis presents a wide tuning, low phase noise CMOS integer-N frequency synthesizer with 1.8V power supply. The frequency synthesizer is designed using the TSMC 0.18£gm CMOS 1P6M technology. The proposed frequency synthesizer consists of a phase-frequency detector, a charge pump, a low-pass loop filter, a voltage control oscillator, an auto-band selection (ABS), an optimum-band selection (OBS), and a pulse-swallow divider. In system design, we present the new architecture for voltage-controlled oscillator with switched capacitors technique with a lowered VCO gain (KVCO) to achieve wide tuning range and low phase noise in order to cover the desired operating frequency bands and to accommodate process, voltage, and temperature (PVT) variations. The ABS accomplishes the efficient search for a VCO discrete tuning curve among a group of frequency sub-bands. It is apparent to reduce the calibration time by adopting the binary search algorithm to select the calibration word. However, the variation of Kvco across different channels can still be large after the execution of ABS. There might be many sub-bands covering the desired frequency. Hence the sub-band which is selected by ABS could not be an optimum choice for the minimum Kvco variation. The OBS is proposed to implement an algorithm in order to find the optimum solution which has the minimum Kvco variation and covers the desired frequency. The Kvco variation is quantified by OBS and using this value to adjust the charge pump current. Therefore, Loop bandwidth and stability were maintained across the operating range by using optimum-band selection(OBS) and a programmable charge pump.