<p> This thesis is concerned with the improvement of the contrast ratio of flexible display devices, which are Sphere Supported Thin Film Electroluminescent (SSTFEL) devices. A two-layer coating system was selected as anti-reflection (AR) coatings to be deposited on the surface of SSTFEL devices to reduce the reflection of the ambient light from the surface of devices based on the interference concept. This AR coating was composed of an ITO layer and an ultra-thin gold layer. In order to maximize destructive interference in the visible wavelength range, the optical properties, including refractive index, transmittance and reflection of ITO films and ultra-thin gold films related to sputtering conditions have been studied. The electrical conductance of these two films has also been explored because these two layers work not only as AR coatings but also as a conductive and transparent electrode of SSTFEL devices. AFM images show that the surface morphology of ultra-thin gold films on Si substrates is similar to that on an ITO layer and on polypropylene sheets. The measurements of specular and diffuse reflectance of AR coatings on the propylene sheets and devices have been performed in detail. Results show that AR coatings have better performance on the devices when the thickness of ultra-thin gold layers and ITO layers are 3.43 to 4.01nm, and 42.5 to 45.0nm respectively. Specular and diffuse reflectance of SSTFEL devices with AR coatings are around 1.3% and 13.6% respectively, which is 6.3 times less than that of devices without AR coatings. The contrast ratio of devices with AR coatings is up to 47.9:1 at the ambient illumination level of 52.6Lux. At the ambient illumination level of 200 Lux, the contrast ratio of SSTFEL devices is 5 times higher than that of SSTFEL devices without AR coatings. </p> <p> During the research on the properties of ultra-thin gold films, it has been observed that the ultra-thin gold film has unreported optical and electric properties when its thickness is around 3nm. Its reflectance spectrum is similar to the reflectance spectrum of the substrate, whether the substrate is a glass slide or a wafer of silicon, and follows the reflectance spectrum of the substrates with an increase of several percent in visible wavelength range. The conductance of the ultra-thin gold film decreases by exponential decay as its thickness decreases for the conductance is based on tunneling effects. However, the conductance suddenly increases while the thickness of the ultra-thin gold layer is decreased at around 3 to 4 nm. This behavior has not been reported and explained. </p> / Thesis / Master of Applied Science (MASc)

Future launch vehicle payload fairings will be manufactured from advanced lightweight composite materials. The loss of distributed mass causes a significant increase in the internal acoustic environment, causing a severe threat to the payload. Using piezoelectric actuators to control the fairing vibration and the internal acoustic environment has been proposed. The control authority of these actuators for this problem has not yet been determined. To help determine the acoustic control authority of piezoelectric actuators mounted on a rocket fairing, the internal acoustic response created by the actuators needs to be determined. In this work the internal acoustic response of a closed simply-supported (SS) cylinder actuated by piezoelectric (PZT) actuators is presented. A research-grade SS cylinder is created and the modal properties are analyzed experimentally. The experimental modal properties are compared to finite element analysis (FEA) and to results predicted by Love shell theory. The experimental results indicate that the created cylinder has dynamic properties that are similar to the analytical and FEA results. The formulation for the structural response uses an impedance model to predict transverse vibration of the cylinder excited by PZT actuators. The model is also shown to be valid. To obtain the internal acoustic response of the cylinder a boundary element analysis using the Kirchoff-Helmholtz integral is used. The motion of the structure is assumed to be uncoupled with the internal acoustics, and so the structural-acoustic interaction is not considered in this analysis. An analytical solution to the internal acoustic response within the cylinder is derived for a single mode structural vibration. The numerical and analytical models are shown to be in agreement. The numerical model is also verified experimentally by measuring the acoustic field within the cylinder. The experimental results and the results predicted by the acoustic model are in agreement. A measure of the acoustic loss factor for the aluminum cylinder is also determined experimentally. The validated model is used to extrapolate results for a SS cylinder that emulates a Minotaur payload fairing. The internal cylinder acoustic levels are investigated for PZT actuation between 35 and 400 Hz. It is found that changes in cylinder parameters (stiffness and material density) do not have a large effect on the magnitude of the structural response. Likewise the interior acoustic response is not greatly affected by changes to the cylinder parameters. As the applied voltage increases linearly, the internal sound pressure level (SPL) varies logarithmically. This behavior is a limiting factor in using a PZT actuator to generate high internal SPLs. Significant reductions in the structural response due to increased damping do not equate to similar reductions in the acoustic SPLs for the cylinder. The sound levels at the acoustic resonant frequencies are essentially unaffected by the significant increase in structural damping while the acoustic levels at the structural resonant frequencies are mildly reduced. The interior acoustic response of the cylinder is dominated by the acoustic modes and therefore significant reductions in the overall interior acoustic levels will not be achieved if only the structural resonances are controlled. The model indicates that the maximum acoustic levels generated by the baseline PZT actuator are sufficient at the higher frequency range but are not commensurate with the levels found in a typical fairing in the lower frequency range (below ~200 Hz). Since the baseline actuator's applied voltage can not be increased, additional actuators are required in order to increase the response of the cylinder at some of the lower frequencies. The baseline actuator is clearly better at generating sound within the cylinder as the frequency increases. This implies that more actuators will be required to control the lower frequency modes than the higher frequency modes. As the actuation frequency is reduced, the number of actuators required to generate acoustic levels commensurate to that found in the fairing increases to impractical values. Below approximately 100 Hz, the current demands reach levels that are extremely difficult to achieve with a practical system. The results of this work imply that PZT actuators do not have the authority to control the payload fairing internal acoustics below ~100 Hz. / Ph. D.

In many catalytic systems, the catalytic performance of a metal supported catalyst would be affected by the size and shape of the metals, and this phenomena is called structure sensitivity. Generally, the structure sensitivity effect is considered being led by a combination of geometric property change and electronic property change of the surface metals. The particle size variation is an effective way to change the surface structure of the supported metal catalyst, leading to different fractions of the active sites exposing on the support that would take effect on catalyzing the reaction. In this project, a series of Ir/MgAl₂O₄ catalysts with different particle sizes that less than 2nm were utilized for ethane and n-butane hydrogenolysis reactions to study the structure sensitivity effect as well as the potential reaction mechanism. The results show that the activity on the catalysts with nanoparticles and mostly single atoms is evidently higher than that with the subnanometer clusters in both reactions, but the selectivity to the target product of ethane is not quite dependent on the particle size in the n-butane hydrogenolysis. After the fundamental analysis, it is proposed that the reaction mechanism of alkanes hydrogenolysis on the single atom catalysts including single active sites is probably distinctive from that generally accepted on the large particles containing multiple active sites from literature. For n-butane hydrogenolysis, the parallel reaction pathway of central C-C bond cleavage is dominant at low temperature or in the low conversion range. As the temperature going up or the conversion increasing at a certain temperature, the parallel reaction pathway of terminal C-C bond cleavage becomes more and more competitive. The series reaction pathway of hydrogenolysis on propane intermediate would always take place, but the level would be drastically enhanced when the conversion keeps increasing in the very high range. The C-C bond cleavage on the ethane product would not easily happen unless the conversion is close to 100%. / M. S. / Shale gas is natural gas trapped in shale rocks. Among all the countries that have abundant shale gas reserves, the US, benefited from advanced extraction technology, has the largest production of it. What’s more, the production rate will keep increasing at least for the coming 20 years, and shale gas will eventually become the largest source for natural gas. After extraction, there is a series of treatments shale gas has to go through before it can be utilized, catalytic reaction of alkanes (molecules found in most fuels) is one of these essential procedures. Although they are among the most important compositions of shale gas, different types of alkanes are difficult to separate and purify through traditional methods like condensation. To overcome this obstacle, this thesis focuses on exploring efficient catalysts to convert the n-butane (a straight chain alkane with 4 carbon atoms) to ethane (alkane with 2 carbon atoms). Two reactions are involved: n-butane hydrogenolysis and ethane hydrogenolysis. Catalysts are some specific materials that can accelerate certain chemical reactions. The catalysts discussed in this thesis are tiny metal (iridium) particles attached to the support material (magnesium aluminate). In this study, the performance of these catalysts with different particle sizes were tested for the above mentioned hydrogenolysis reactions. The results show that changing the particle size of the catalysts considerably affects the rate of these catalytic reactions. The fundamentals of the catalytic system presented in this work can also help the researchers to rationally design the catalysts aiming at higher efficiency and lower cost in the future work.

The purpose of this research is to examine the barriers to food security for single adults with mental illness and/or problematic substance use living in supported housing on Vancouver Island. The objectives are: (a) to examine the difference in the level of food security for tenants of supported housing neighbourhoods located in urban versus a rural community; (b) to examine the barriers to food access experienced by the tenants; and (c) to examine which barriers have the greatest effect on the tenants. Using an explanatory case study design, I employ a community-based research method with a social justice perspective as the framework. I have used an explanatory matrix to illustrate the tenant identified barriers to food security and the social structures that affect these barriers. As well, I have made recommendations for integrating food security services and programs into supported housing projects. I have argued that food security is a matter of public health and an integrative approach is needed. I am suggesting a shift on a larger policy scale, to promote the health and well-being of tenants in supported housing. An adequate holistic perspective with an integrated, long-term strategy linking all the determinants of health would result in health-in-all policies. This strategy could reduce the existing health inequities that the tenants in supported housing experience. / Graduate / judy@nahs.ca

This thesis has investigated the application of CFRP and GFRP bars as longitudinal reinforcement for continuously supported concrete beams. Two series of simply and continuously supported CFRP and GFRP reinforced concrete beams were tested in flexure. In addition, a continuously supported steel reinforced concrete beam was tested for comparison purposes. The FRP reinforced concrete continuous beams were reinforced in a way to accomplish three possible reinforcement combinations at the top and bottom layers of such continuous beams. The experimental results revealed that over-reinforcing the bottom layer of either the simply or continuously supported FRP beams is a key factor in controlling the width and propagation of cracks, enhancing the load capacity, and reducing the deflection of such beams. However, continuous concrete beams reinforced with CFRP bars exhibited a remarkable wide crack over the middle support that significantly influenced their behaviour. The ACI 440.1R-06 equations have been validated against experimental results of beams tested. Comparisons between experimental results and those obtained from simplified methods proposed by the ACI 440 Committee show that ACI 440.1R-06 equations can reasonably predict the load capacity and deflection of the simply and continuously supported GFRP reinforced concrete beams tested. However, The potential capabilities of these equations for predicting the load capacity and deflection of continuous CFRP reinforced concrete beams have, however, been adversely affected by the de-bonding of top CFRP bars from concrete. An analytical technique, which presents an iterative procedure based on satisfying force equilibrium and deformation compatibility conditions, has been introduced in this research. This technique developed a computer program to investigate flexural behaviour in particular the flexural strength and deflection of simple and continuously supported FRP reinforced concrete beams. The analytical modelling program has been compared against different prediction methods, namely ACI 440, the bilinear method, mean moment inertia method and Benmokrane's method. This comparison revealed the reliability of this programme in producing more enhanced results in predicting the behaviour of the FRP reinforced beams more than the above stated methods.

Syftet med studien var att undersöka vilka faktorer i psykiatrisk rehabiliteringsteori som var de viktigaste stödjande och hindrande faktorerna för att deltagare i arbetslivsinriktad rehabilitering skulle kunna slutföra gymnasial/eftergymnasial utbildning och få ett arbete på dagens arbetsmarknad. Deltagarna i denna studie kom från fyra verksamheter inom Supported Education (SEd) i Sverige. Faktorerna för både stödjande och hindrande faktorer ville jag få fram i prioritetsordning, eftersom jag från tidigare forskning upplevde det svårt att veta vad som först ska prioriteras i arbetet med rehabilitering genom utbildning och arbete/anställning. Detta för att skapa en djupare förståelse för vad som är viktigt för personer med psykiska funktionshinder/ohälsa för att påbörja och slutföra utbildning, men också för att se om tjänsten SEd har potential att användas inom socialt arbete i form av arbetslivsinriktad rehabilitering och återhämtningsinriktat stöd för psykisk ohälsa och psykiska funktionshinder. För att besvara detta använde jag en enkät med tio kvantitativa slutna frågor och sju kvalitativa öppna frågor.      SEd är ett stödprogram inom arbetslivsinriktad rehabilitering för att välja, påbörja och slutföra utbildning på gymnasial och eftergymnasial nivå främst för personer med psykiska funktionshinder/psykisk ohälsa. Diskussioner pågår om att andra målgrupper utan psykiska funktionshinder/psykisk ohälsa ska kunna få detta stöd för att slutföra utbildningar.      Från resultatet av studien fick jag fram ett antal teman för vad som stödjer och hindrar slutförandet av utbildning. Resultatet visade att deltagarna generellt är nöjda med stödet de får från SEd. Mest framträdde personalens genuina engagemang, förmåga till empati och ett respektfullt bemötande som de avgörande faktorerna för att deltagarna skulle påbörja och slutföra utbildning. Andra faktorer som stödde deltagarna var att de fick stöd att slutföra studieuppgifter, att stödet inte var tidsbegränsat, att deltagarna hade regelbundna enskilda stödsamtal med personal, att de upplevde gemenskap och tillhörighet i SEd och att studie- och yrkesvägledning genomfördes som ledde till en individuell handlingsplan som följdes upp kontinuerligt.        Hindrande faktorer för deltagarna med SEd var att lokalerna var för små och studiecoacherna var för få. Generella hinder för deltagarna att slutföra utbildning var psykisk ohälsa (till exempel ångest, fobi, depression), svårigheter med studieekonomin, svårigheter med socialt samspel, svårigheter med koncentration, brist på studieteknik och svårigheter att slutföra uppgifter, ADHD, ADD, dyslexi, missbruk, svårigheter med att orka med ett högt studietempo och brist på stöd med att slutföra uppgifter. Detta resultat analyserade jag med hjälp av psykiatrisk rehabiliteringsteori. Jag förde sedan en diskussion där jag lyfte fram de utmaningar och möjligheter som vi kan se i framtiden för SEd. / The purpose of this study was to examine which factors in the psychiatric rehabilitation theory that were the most important supporting and hindering factors for getting participants in Vocational Rehabilitation to complete secondary/postsecondary education and get a job in todays labour market. The participants in this study came from four Supported Education (SEd-) projects in Sweden. I wanted to get forth the factors in order of priority since I found it difficult to find which factors to prioritize first in the work of rehabilitation through education and employment. I did this to get a deeper understanding of what is most important for persons with psychiatric disabilities/mental illness to be able to complete secondary/postsecondary education, but I also did it to investigate if the service of SEd has the potential of being used in social work in the shape of vocational rehabilitation and recoveryoriented support for mental illness and psychiatric disabilities. To be able to answer those questions I used a questionnaire with ten quantitative closed questions and seven qualitative open questions..      Supported Education (SEd) is a supportprogram aimed at supporting persons mainly with psychiatric disabilities/mental illness to choose, start and complete education on secondary and postsecondary level. There are ongoing discussions about whether other target groups without psychiatric disabilites/ mental illness could get this support to complete education.       From the results of the study I found a number of themes for what supported or hindered the participants in completing their education. The results showed that the participants generally were very satisfied with the support they got from the staff in SEd. Most of all it was the staffs genuine engagement, empathy and a respectful treatment that stood forth as the crucial factors that affected the participants to complete their education. Other factors that also supported the participants to complete their education is that they got support with completing their study tasks, there were no time limit for the support, the recurrent individual counseling sessions with staff, the experience of fellowship and belonging and educational and vocational guidance that supported the participants in forming an individual action plan which was followed up continuosly.       Hindering factors with SEd for the participants were that the localities were too small and that the study coaches were too few. Hindering factors in completing education in general was mental illness (e.g. anxiety, phobia and depression), difficulties with economy, difficulties in socialising with people, difficulties with concentration, lack of a technique for studying and difficulties with completing tasks, ADHD,ADD, dyslexia, addiction, problems to adjust to a high tempo in the education and lack of support with completing tasks. I analyzed these results by using the psychiatric rehabilitation theory. I then discussed the challenges and possibilities that we can see in the future with the SEd-method.

Record high CO2 emissions in the atmosphere and the need to find alternative energy sources to fossil fuels are major global challenges. Conversion of CO2 into useful fuels like methanol and methane can in principle tackle both these environment and energy concerns. One of the routes to convert CO2 into useful fuels is by using supported metal catalyst. Specifically, metal atoms or clusters (few atoms large in size) supported on oxide materials are promising catalysts. Experiments have successfully converted CO2 to products like methanol, using TiO2 supported Cu atoms or clusters. How this catalyst works and how CO2 conversion could be improved is an area of much research. We used a quantum mechanical tool called density functional theory (DFT) to obtain atomic and electronic level insights in the CO2 reduction processes on TiO2 supported metal atoms and clusters. We modeled small Cu clusters on TiO2 surface, which are experimentally synthesizable. Our results show that the interfacial sites in TiO2 supported Cu are able to activate CO2 into a bent configuration that can be further reduced. The Cu dimer was found to be the most reactive for CO2 activation but were unstable catalysts. Following Cu, we also identified other potential metal atoms that can activate CO2. Compared to expensive and rare elements like Pt, Au, and Ir, we found several early and mid transition metals to be potentially active catalysts for CO2 reduction. Because the supported metal atom or cluster is a reactive catalyst, under reaction conditions they tend to undergo aggregation and/or oxidation to form larger less active catalysts. We chose Co, Ni, and Cu group elements to study their catalyst stability under oxidizing reaction conditions. Based on the thermodynamics of Cu oxidation and kinetics of O2 dissociation, we found that TiO2 supported Cu atom or a larger Cu tetramer cluster were the likely species observed in experiments. Our work provides valuable atomic-level insights into improving the CO2 reduction activities and predicts potential catalysts for CO2 reduction to valuable fuels.

Zugl.: St. Gallen, Universiẗat, Diss., 1995.

This thesis has investigated the application of CFRP and GFRP bars as longitudinal reinforcement for continuously supported concrete beams. Two series of simply and continuously supported CFRP and GFRP reinforced concrete beams were tested in flexure. In addition, a continuously supported steel reinforced concrete beam was tested for comparison purposes. The FRP reinforced concrete continuous beams were reinforced in a way to accomplish three possible reinforcement combinations at the top and bottom layers of such continuous beams. The experimental results revealed that over-reinforcing the bottom layer of either the simply or continuously supported FRP beams is a key factor in controlling the width and propagation of cracks, enhancing the load capacity, and reducing the deflection of such beams. However, continuous concrete beams reinforced with CFRP bars exhibited a remarkable wide crack over the middle support that significantly influenced their behaviour. The ACI 440.1R-06 equations have been validated against experimental results of beams tested. Comparisons between experimental results and those obtained from simplified methods proposed by the ACI 440 Committee show that ACI 440.1R-06 equations can reasonably predict the load capacity and deflection of the simply and continuously supported GFRP reinforced concrete beams tested. However, The potential capabilities of these equations for predicting the load capacity and deflection of continuous CFRP reinforced concrete beams have, however, been adversely affected by the de-bonding of top CFRP bars from concrete. An analytical technique, which presents an iterative procedure based on satisfying force equilibrium and deformation compatibility conditions, has been introduced in this research. This technique developed a computer program to investigate flexural behaviour in particular the flexural strength and deflection of simple and continuously supported FRP reinforced concrete beams. The analytical modelling program has been compared against different prediction methods, namely ACI 440, the bilinear method, mean moment inertia method and Benmokrane¿s method. This comparison revealed the reliability of this programme in producing more enhanced results in predicting the behaviour of the FRP reinforced beams more than the above stated methods.

Constructing common ground and the associated convergent conceptual change is critical to cooperative work and learning. Convergent conceptual change is achieved as participants in a conversation update common ground through presentations, repairs, and acceptances of utterances. People employ available techniques that utilize the least collaborative effort for current purposes. Although sharing physical co-presence of interlocutors' facial expressions doesn't make grounding more efficient even in more open-ended and less task-focused dialogues, visual co-presence of the addressee's workspace is essential to work-related tasks, such as information transmission and collaborative problem-solving. However, handheld-mediated collaborative activity makes sharing the workspace challenging, especially when we consider that handhelds possess small screens and permit activities of a distributed nature. In a handheld-mediated classroom, a teacher must be able to check students' work for various reasons (e.g., grading, checking whether they are following directions correctly or paying attention) and at various phases of the activity. Gazing into the small screen of a handheld over someone's shoulder is a tricky task at best. The teacher may misread the information on the screen and thus provide incorrect feedback. Another challenge involves the difficulty inherent in latecomers joining the collaborative activity when each student is involved with his or her individual and small screen. This exclusion from joining on-going activity can reduce the chance of student's vicarious and serendipitous learning. Although such events may occur naturally in the learning environment, they become important concerns when one attempts to focus collaborative activities with handheld devices. I therefore created a new handheld network service called "Look," which is designed to facilitate the acquisition of common ground and allow a latecomer to do meaningful monitoring of ongoing conversation about the workspace. I tested empirically the value of this shared physical/virtual context in the task of creating common ground by examining task performance and conversation quality. / Ph. D.