Superhydrophobic (SH) surfaces are super water repellent surfaces on which a droplet of water will bead up like a marble and roll off the surface with minimal tilting of the surface. This is caused by the combination of a hydrophobic coating and a rough surface structure. To achieve thermodynamic stability, surface tension of the water pulls the droplet into this shape to minimize the contact area between the droplet and the surface. This creates a high contact angle (CA) between the droplet and the surface and a low sliding angle (SA) of which the droplet begins to roll off the surface. SH surfaces have a variety of potential applications such as drag reduction, anti-icing, improved heat transfer through condensation, and self-cleaning. Numerous reports have been dedicated to exploring the fluid dynamic behavior of water droplets on SH surfaces. This thesis focuses on exploring the self-cleaning properties of SH surfaces. Surfaces contaminated with salt, tobacco, and pollen are cleaned by rolling water droplets over the surface or condensing water on the surface such that when large enough, these droplets roll away due to gravity. SH surfaces explored here are composed of micro-scale or nano-scale rib and cavity structures and are compared with smooth, hydrophobic surfaces with a similar hydrophobic coating. To determine the self-cleaning efficiency of each surface, the CA and SA were measured before and after each surface was cleaned. In this study, it was observed that the presence of each of the three contaminates considered greatly affects the overall hydrophobicity of the surface, as indicated by the CA and SA. Ideally, as the contaminates are removed from the surface, the hydrophobicity of the surface improves to match the hydrophobicity of a clean surface. This is best seen on surfaces contaminated with salt as the CA and SA match that of a clean surface after only two to three water droplets roll over the surface or after the first condensed water droplets roll off the surface. This implies that all the salt particles are removed from the SH surface. Surfaces contaminated with tobacco showed that the hydrophobicity improves to a limited extent when cleaned with rolling water droplets or condensation but never is capable of matching the hydrophobicity of a clean surface. This suggests that only a portion of the tobacco residue is capable of being removed from the surface by either of the two cleaning methods considered in this thesis. Finally, when water came in contact with pollen on the surfaces, it experienced hydrodynamic osmosis leading to cellular bursting. After cellular bursting, the surface behaves as a hydrophilic surface and selfcleaning properties were never observed on any surface contaminated with pollen. Thus, overall this study shows that rolling water droplets over a contaminated surface and condensing water droplets on a contaminated surface are both viable means of utilizing the self-cleaning properties on SH surfaces. For the contaminates considered in this study, the efficiency of the self-cleaning surfaces is shown to be the same for both micro-structured and nano-structured surfaces.

Synthetic membranes have a high separation efficiency, small footprint, low energy consumption and ease of operation, making them an attractive alternative to traditional separation operations. For this reason, membranes have been extensively studied for the treatment and recycling of bitumen-containing wastewaters. Such wastewaters include petroleum produced water, residual pipeline cleaning solutions and contaminated water from oil spills. Ceramic membranes are preferred in these applications over polymeric membranes because they are highly resistant to solvents and can be operated at high temperatures over a wide range of pH. Fine clays and silicates, coated with bitumen, are significant foulants for membrane filtration systems. These foulants possess acidic, basic and amphoteric groups, leading to the presence of both positive and negative surface charges. Ceramic membranes in aqueous media have a pH dependent surface charge. It was hypothesized that these surface charges are responsible for the high fouling of ceramic membranes that is observed when treating wastewaters containing bituminous fines. The overall objective of this research was to reduce fouling and increase the lifetime of ceramic membranes in treating oil sands produced water; an example of a wastewater containing bituminous fines. This goal was achieved through the surface modification of the ceramic membrane’s selective layer, as well as by the implementation of a novel in-place steam regeneration technique. All membrane filtration tests were performed with field samples of oil sands produced water that were supplied to CanmetMINING (NRCan) by three Canadian oil sands companies. Organosilanes are silicon-based monomers that can possess a wide array of chemical functionality due to their organic moieties. They are capable of reacting with oxide surfaces, and have seen extensive use as surface modification agents for ceramic membranes in various applications. To maintain desirable hydrophilic properties without surface charges, highly hydrophilic and non-ionic polyethylene oxide (PEO) based organosilanes were identified. These PEO-silanes were then used to modify ceramic membranes of several different selective layer materials, and the thermal stability of the silane layer was studied using FTIR, SEM, zeta potential and contact angle measurements. The modification procedure with PEO-silanes was first applied to lab-scale membrane disks, and subsequently to commercial scale multilumen membrane tubes that were tested in a pilot-scale system at CanmetMINING. Results obtained from both sets of experiments were promising and demonstrate that ceramic membranes can be surface modified in a way that successfully renders them fouling resistant to the bituminous fines present in these wastewaters. Upon surface modification, foulants were more readily released from the membrane surface, resulting in an enhanced flux and separation performance. A novel steam regeneration technique was also applied as a means of bituminous fouling alleviation. This technique was tested in the CanmetMINING pilot-scale system and consisted of periodically injecting steam into the membrane lumen feed channels during operation. Direct steam injection rapidly heated foulant cake layers, and water droplets in the saturated steam caused surface abrasions that ultimately resulted in the scouring of bitumen away from the membrane surface. Membrane fluxes when steam regeneration was active were up to 4 times higher when compared to tests where only traditional permeate backflushing was used. The fouling remediation techniques developed in this work have broad potential applicability in ceramic membrane filtration systems aimed at treating all wastewaters containing bituminous compounds, such as process waters in general and contaminated water from oil spills.

Doctor of Philosophy / This thesis describes experiments which were carried out at the Institute of Dental Research in Sydney and within the Department of Prosthetic Dentistry at the United Dental Hospital of Sydney between February 1991 and May 1996. The study is concerned with finding practical means of treating chronic atrophic candidosis, also referred to as Candida-associated denture stomatitis and to this purpose two methods of denture disinfection are investigated, namely, sodium hypoclorite denture soak and microwave irradiation. Although the aetiology of denture stomatitis is generally considered to be multifactorial, there is sufficient evidence that Candida species and in particular C. albicans play an important role in the aetiology of the condition. In Chapter 1, therefore, the literature review, which provides relevant background information for the experiments to be described in later chapters, is primarily concerned with Candida species. The characteristics and distribution of Candida species are described and factors affecting the distribution of or Candida are discussed. The literature relating to the cause of chronic atrophic candidosis is vast and consequently a detailed description is given of Candida-associated denture stomatitis in the section concerned with oral diseases caused by Candida and their treatment. Each of the subsequent chapters, contains a brief literature review of material relevant to the subject of the particular chapter. Chapter 2 describes laboratory work to assess the effect of sodium hypochlorite on the adhesion of Candida species to oral surfaces and the ability of Candida to coaggregate with oral streptococci. The results showed that sodium hypochlorite decreased the ability of Candida species to adhere to both inert surfaces and BECs. However, coaggregation of Candida with streptococci was increased. Thus, hypochlorite if used as a denture soak may initially reduce the ability of Candida species to adhere to the denture surface and may therefore assist the treatment of denture stomatitis. The effects of hypochlorite on the characteristics of Candida species that are associated with tissue invasion are described in Chapter 3. The production of acid proteinase, the formation of germ tubes and presence of major cell wall proteins at 43 and 27 kDa are demonstrated. The ability of the whole cells of certain species of Candida to aggregate human platelets was assessed. The results showed that sodium hypochlorite did not affect proteinase production by Candida species but the rate of germ tube formation and the production of Candida cell wall proteins were increased. Hypochlorite did not affect the ability of certain Candida species to aggregate human platelets. Mechanisms to defend the host against candidal invasion are discussed and include platelet aggregation where aggregated platelets release antimicrobial factors that are active against Candida. Chapter 4 describes an in vitro study to test the effects of sodium hypochlorite and microwave irradiation on the survival of Candida species and oral streptococci on denture surfaces. The results showed that 0.02% sodium hypochlorite denture soak for 8 h will eliminate Candida species and reduce the growth of streptococci. However, microwaving of dentures at medium setting for 6 min will eliminate both Candida and streptococci. This information servers as baseline data for clinical assessments described in Chapters 7 and 8. Denture hygiene is an important factor in the prevention and treatment of Candida-associated denture stomatitis. Hence, a clinical study to assess the microbiology of denture plaque is described in Chapter 5. The results showed that denture plaque was composed mainly of Gram-positive streptococci with varying proportions of Gram-positive rods, Gram-negative cocci and rods and is similar to dental plaque. Candida was not always isolated and when detected constituted a very small proportion (< 1%) of the total aerobic bacterial count. The results of an investigation to test the effect of soft denture liners in lower dentures on the colonization of denture surfaces by Candida species and aerobic bacteria are given in Chapter 6. There was no significant difference in Candida /bacterial colonization of dentures with soft denture liners and those without liners. Chapter 7 describes a clinical study to test the efficiency of sodium hypochlorite (0.02%) over-night denture soak as an effective denture disinfecting agent. Treatment of dentures with hypochlorite over a trial period resulted in reductions of Candida and aerobic bacteria and although the reductions were not significant the effect over the trial period could be assessed. A significant finding was that for the palate, treatment with hypochlorite over the trial period prevented an increase in candidal load. Thus, sodium hypochlorite may function as an effective disinfecting agent when used as 0.02% denture soak for a prolonged period. A pilot study to assess the effectiveness of microwaving dentures for ten min (350 W, 240 MHz) as a potential method of denture disinfection is described in Chapter 8. For practical reasons the dentures were microwaved only once only and therefore the effect over a trial period could not be assessed. However, one treatment resulted in significant reductions in the levels of Candida and aerobic bacteria. These findings have indicated that future research should be carried out to test the effect of daily consecutive microwave treatments on candidal and bacterial growth. The general discussion in Chapter 9 summarizes the data presented in the previous chapters and from the findings conclusions are made concerning the prevention and treatment of Candida-associated denture stomatitis. The limitations of this thesis are recognized and some important aspects of the study are recommended for future research.

<p>This thesis work has been performed at the Division of Assembly Technology at Linköping University for a period of ten weeks. The work is part of the project ProFlexA, which is a research project in collaboration between Linköping University, Lund University, and industrial partners such as Combi Wear Parts and Smålands Stålgjuteri AB.</p><p>The casting process creates random incurred burrs and defects, which must be removed during a cleaning process to make sure that the cast can be sold. Automation has long been sought for the cleaning of castings due to, among other things, poor working conditions for staff, but this has proved difficult to implement with today's technology. Automation has for some time been available for more capital strong companies with large annual volumes, but for smaller companies with small-and medium-sized volumes, automation has not been an option.</p><p>The goal of ProFlexA is to develop an automated cleaning cell aimed at small-and medium-sized volumes.</p><p>The goal of the thesis is to do a pre study at ProFlexA’s partners on cleaning of castings, and develop concepts for automated cleaning of castings.</p><p>By recording the process and cycle times, the cleaning of castings has been documented as it works today, and on this basis, information and statistics has been compiled. Conclusions have been drawn on preventive measures that may facilitate the development of an automated cleaning cell.  One of these is to change the geometry of the steel riser so that the resulting stub after removal by the pneumatic hammer is more controlled, and another measure is to relocate the location of the riser stub to an equal side of all the products. It is also important to prevent the defect caused by sand residues.</p><p>Based on the documentation, it has been revealed that the product often is over-worked, which implies that an automated cell would provide a more even quality.</p><p> </p><p>Forces that occur in an operation of cleaning of castings have been measured. The results suggest that the forces in this context are 100 to 180 Newton, which indicates that the robot selected to the project, IRB 6660, is likely to be oversized. It can therefore be discussed if it is relevant with the current safety factor or if there is a reason to search for a smaller robot.</p><p>Proposals have been prepared on concepts of automated cleaning of castings. These concepts show how a robotic cell can work when a single robot, compared with two robots are part of a cell, but also how it works with stationary tools compared with mobile tools.</p><p>The design of a robotic cell should be sought in the objectives and needs of the specific company. A robotic cell with two robots is for example to be preferred when the need for efficiency is higher. Tools to a robotic cell is built in the simplest possible terms by a motor, a spindle and a tool, which is the option that seems to be a good choice in terms of whole and investment friendliness.</p><p>For Combi Wear Parts a robotic cell with two robots is suitable, and for Smålands Stålgjuteri AB a robotic cell with a single robot is probably the best choice. For both of these solutions small and economic stationary tools would probably suit well.</p>

Since its first use in human in 1929, the electroencephalogram (EEG) has become one of the most important diagnostic tool in clinical neurophysiology. However, their use in clinical studies is limited because the huge quantity of collected information is complicated to treat. Indeed, it is very difficult to have an overall picture of this multivariate problem. In addition to the impressive quantity of data to be treated, an intrinsic problem with electroencephalograms is that the signals are "contaminated" by body signals not directly related to cerebral activity. However, these signals do not interest us directly to evaluate treatment effect on the brain. Removing these signals known as "parasitic noise" from electroencephalograms is a difficult task. We use clinical data kindly made available by the pharmaceutical company Eli Lilly (Lilly Clinical Operations S.A., Louvain-la-Neuve, Belgium). Particular types of analyses were already carried out on these data, most based on frequency bands. They mainly confirmed the enormous potential of EEG in clinical studies without much insight in the understanding of treatment effect on the brain. The aim of this thesis is to propose and evaluate a panel of statistical techniques to clean and to analyze electroencephalograms. The first presented tool enables to align curves such as selected parts of EEGs before any further statistical treatment. Indeed, when monitoring some continuous process on similar units (like patients in a clinical study), one often notices a typical pattern common to all curves but with variation both in amplitude and dynamics across curves. In particular, typical peaks could be shifted from unit to unit. This complicates the statistical analysis of sample of curves. For example, the cross-sectional average usually does not reflect a typical curve pattern: due to shifts, the signal structure is smeared or might even disappear. Another of the presented tools is based on the preliminary linear decomposition of EEGs into statistically independent signals. This decomposition provides on the one hand an effective cleaning method and on the other hand a considerable reduction of the quantity of data to be analyzed. The technique of decomposition of our signals in statistically independent signals is a well-known technique in physics primarily used to unmix sound signals. This technique is named Independent Component Analysis or ICA. The last studied tool is functional ANOVA. The analysis of longitudinal curve data is a methodological and computational challenge for statisticians. Such data are often generated in biomedical studies. Most of the time, the statistical analysis focuses on simple summary measures, thereby discarding potentially important information. We propose to model these curves using non parametric regression techniques based on splines.

Research was performed to study the particle adhesion on the wafer surface after the chemical-mechanical polishing (CMP) process. The embedded particles can be abrasive particles from the slurry, debris from pad material, and particles of film being polished. Different methods of particle removal mechanism were investigated in order to find out the most effective technique. In post-CMP cleaning, surfactant was added in the solution. Results were compared with cleaning without surfactant and showed that cleaning was more effective with the combined interaction of the mechanical effort from the brush sweeping and the chemistry of the surfactant in the solution (i.e., tribochemical interaction). Numerical analysis was also performed to predict the particle removal rate with the addition of surfactants. The van der Waals forces present in the wafer-particle interface were calculated in order to find the energy required to remove the particle. Finally, the adhesion process was studied by modeling the van der Waals force as a function of separation distance between the particle and the surface. The successful adaptation of elasticity theory to nanoparticle-surface interaction brought insight into CMP cleaning mechanisms. The model tells us that it is not always the case that as the separation distance is decreased, the attraction force will be increased. The force value estimated can be used for slurry design and CMP process estimation.

With the growth of computer networks and the advancement of hardware technologies, unprecedented access to data volumes become accessible in a distributed fashion forming heterogeneous data sources. Understanding and combining these data into data warehouses, or merging remote public data into existing databases can significantly enrich the information provided by these data. This problem is called data integration: combining data residing at different sources, and providing the user with a unified view of these data. There are two issues with making use of remote data sources: (1) discovery of relevant data sources, and (2) performing the proper joins between the local data source and the relevant remote databases. Both can be solved if one can effectively identify semantically-related attributes between the local data sources and the available remote data sources. However, performing these tasks manually is time-consuming because of the large data sizes and the unavailability of schema documentation; therefore, an automated tool would be definitely more suitable. Automatically detecting similar entities based on the content is challenging due to three factors. First, because the amount of records is voluminous, it is difficult to perceive or discover information structures or relationships. Second, the schemas of the databases are unfamiliar; therefore, detecting relevant data is difficult. Third, the database entity types are heterogeneous and there is no existing solution for extracting a richer classification result from the processing of two different data types, or at least from textual and numerical data. We propose to utilize self-organizing maps (SOM) to aid the visual exploration of the large data volumes. The unsupervised classification property of SOM facilitates the integration of completely unfamiliar relational database tables and attributes based on the contents. In order to accommodate heterogeneous data types found in relational databases, we extended the term frequency – inverse document frequency (TF-IDF) measure to handle numerical and textual attribute types by unified vectorization processing. The resulting map allows the user to browse the heterogeneously typed database attributes and discover clusters of documents (attributes) having similar content. iii The discovered clusters can significantly aid in manual or automated constructions of data integrity constraints in data cleaning or schema mappings for data integration.

This thesis work has been performed at the Division of Assembly Technology at Linköping University for a period of ten weeks. The work is part of the project ProFlexA, which is a research project in collaboration between Linköping University, Lund University, and industrial partners such as Combi Wear Parts and Smålands Stålgjuteri AB. The casting process creates random incurred burrs and defects, which must be removed during a cleaning process to make sure that the cast can be sold. Automation has long been sought for the cleaning of castings due to, among other things, poor working conditions for staff, but this has proved difficult to implement with today's technology. Automation has for some time been available for more capital strong companies with large annual volumes, but for smaller companies with small-and medium-sized volumes, automation has not been an option. The goal of ProFlexA is to develop an automated cleaning cell aimed at small-and medium-sized volumes. The goal of the thesis is to do a pre study at ProFlexA’s partners on cleaning of castings, and develop concepts for automated cleaning of castings. By recording the process and cycle times, the cleaning of castings has been documented as it works today, and on this basis, information and statistics has been compiled. Conclusions have been drawn on preventive measures that may facilitate the development of an automated cleaning cell.  One of these is to change the geometry of the steel riser so that the resulting stub after removal by the pneumatic hammer is more controlled, and another measure is to relocate the location of the riser stub to an equal side of all the products. It is also important to prevent the defect caused by sand residues. Based on the documentation, it has been revealed that the product often is over-worked, which implies that an automated cell would provide a more even quality.   Forces that occur in an operation of cleaning of castings have been measured. The results suggest that the forces in this context are 100 to 180 Newton, which indicates that the robot selected to the project, IRB 6660, is likely to be oversized. It can therefore be discussed if it is relevant with the current safety factor or if there is a reason to search for a smaller robot. Proposals have been prepared on concepts of automated cleaning of castings. These concepts show how a robotic cell can work when a single robot, compared with two robots are part of a cell, but also how it works with stationary tools compared with mobile tools. The design of a robotic cell should be sought in the objectives and needs of the specific company. A robotic cell with two robots is for example to be preferred when the need for efficiency is higher. Tools to a robotic cell is built in the simplest possible terms by a motor, a spindle and a tool, which is the option that seems to be a good choice in terms of whole and investment friendliness. For Combi Wear Parts a robotic cell with two robots is suitable, and for Smålands Stålgjuteri AB a robotic cell with a single robot is probably the best choice. For both of these solutions small and economic stationary tools would probably suit well.

Snow cleaning is one of the important tasks in the winter time in Sweden. Every year government spends huge amount money for snow cleaning purpose. In this thesis we generate a shortest road network of the city and put the depots in different place of the city for snow cleaning. We generate shortest road network using minimum spanning tree algorithm and find the depots position using greedy heuristic. When snow is falling, vehicles start work from the depots and clean the snow all the road network of the city. We generate two types of model. Models are economic model and efficient model. Economic model provide good economical solution of the problem and it use less number of vehicles. Efficient model generate good efficient solution and it take less amount of time to clean the entire road network.

SOLVATTEN is a household water cleaning device that cleans water with solar energy using filtration, pasteurization and UV sterilization. A field study of the necessary amount of solar insolation that is required to make water drinkable has been carried out in Kenya using a new type of indicator developed by Solvatten AB.  This new indicator will complement the old one, which only registers the temperature, with new features to store information about temperature and insolation. The indicators have been calibrated for energy and temperature and a Matlab program has been developed to analyze the information registered by the indicators. The program handles the time shifting that occurs since the indicator only saves the data at some point during a quarter of an hour. It also handles temperature correction and does a suitable curve fitting using polyfit and spline. The experiments have been divided into two parts, one where the relationship between UV and total solar insolation has been studied and one where we have taken water samples and studied the limiting factors of temperature, UV and total insolation for drinkable water. Previous studies have showed that the water in SOLVATTEN gets clean at 55 C. To reach this temperature the required UV245-400 and UV190-570 insolation is 83.0 Wh/m2 and 307 Wh/m2 according to our tests. The required total insolation is 2680 Wh/m2. From our measurement it can be seen that it is possible for water to be clean at 53 °C. During our artificial tests where we pre-heated the water and thus decreased the total insolation, we never got below 8.2 Wh/indicator which correspond to 1940 Wh/m2 of total insolation at 55 °C. The limit for clean water shown from earlier tests by Solvatten AB is 8 Wh/indicator. Even when the temperature was lower than 55 °C and we got clean water, the insolation was never below this value. This means that it is the temperature that is the limiting factor; however the synergy effect with the insolation is essential for the cleaning process. When it is cloudy the amount of UV that SOLVATTEN receives will be lower compared to the total insolation. With more clouds the temperature will drop and rise many times, while the insolation continues to increase. This means that more clouds will give more total insolation. The shortest time it took to reach 55 °C was 1 hours and 45 minutes at an optimal angle to the sun. / SOLVATTEN är en vattenreningslösning för hushåll som kombinerar filtrering, uppvärmning samt UV-strålning för att döda bakterier. Det är en 11 liters plastdunk, där ena sidan är genomskinlig, och efter att den har exponerats i solen mellan 2- 6 timmar är vattnet rent. En fältstudie har genomförts i Kenya för att undersöka exakt hur mycket solinstrålning som krävs för att vattnet ska bli rent. Idag finns det en väl fungerande indikator som mäter vattnets temperatur men en ny indikator har tagits fram av Solvatten AB som även mäter solinstrålningen och kan lagra den tillsammans med vattentemperaturen. Indikatorerna har kalibrerats för att få rätt energi och temperatur och ett Matlab-program har utvecklats för att kunna analysera informationen. För att kunna ta fram exakta värden används funktionerna polyfit och spline för att kurvanpassa datan. Programmet tar även hänsyn och korrigerar för de fel som kan uppkomma då tiden sparas. Dessa tidsfel uppkommer då indikatorerna endast skriver informationen någon gång under en kvart. Fältstudien är uppdelad i två delar, en där relationen mellan UV och total instrålning har studerats och en där vattenprover har tagits för att undersöka vilken som är den begränsande faktorn för rent vatten; temperatur, UV eller total instrålning. Tidigare studier har visat att SOLVATTEN blir rent vid 55 C. För att lyckas uppnå denna temperatur har det i vår studie krävts 83.0 Wh/m2 av UV245-400 och 307 Wh/m2 av UV190-570. När det gäller den totala instrålningen har det behövts 2680 Wh/m2. Vi har sett att det är möjligt för vattnet att bli rent vid 53 °C. Under våra tester då vi förvärmde vattnet och på sätt fick mindre instrålning, lyckades vi aldrig få under 8.2 Wh/indikator vilket motsvarar 1940 Wh/m2 av totala instrålningen, detta vid 55 °C. Tidigare tester av Solvatten AB visar att det behövs 8 Wh/indikator för att uppnå rent vatten och då vi aldrig lyckades få in mindre instrålning än så tyder det på att det är temperaturen som är den begränsande faktorn. Dock är instrålningen nödvändig då det är synergieffekten mellan värme och instrålningen som uppnår rent vatten vid så låga temperaturer. Om det är mycket moln på himlen sjunker och ökar temperaturen många gånger medan solinstrålningen fortsätter att ackumuleras. Detta betyder att den instrålade energin som når SOLVATTEN blir högre då det krävs längre exponeringstid för att nå 55 °C. Dock har vi sett att mängden UV inte ökar lika mycket som den totala instrålningen men ett generellt förhållande av hur UV och total instrålning förändras vid molnigt väder är dock svårt att kunna få fram. Den kortaste tiden för att uppnå rent vatten är 1 timme och 45 minuter då SOLVATTEN har haft en optimal vinkel mot solen.