Polymer light-emitting electrochemical cells (LECs) are unique solid-state light-emitting devices operating on the principle of in situ electrochemical doping and the formation of a p-n junction. Compared to conventional polymer light-emitting diodes, LECs possess some favorable device characteristics, making them attractive candidates for flat panel display applications. However, the underlying operating mechanism of LECs has been the subject of intense scrutiny and debate. The extremely large planar devices demonstrated by Dr. Gao’s group offer an unparalleled spatial resolution for investigating the electrochemical doping process. With time-lapse fluorescence imaging, our group has demonstrated the existence of the electrochemical doping and the p-n junction in an operating LEC. However, the LEC electronic structure has never been adequately studied and understood. In this thesis, the original research on the electrical and optical scanning measurements on extremely large planar LECs is described. A fresh LEC film has, for the first time, been turned on to form a light-emitting p-n junction by biasing a pair of probes that form direct contacts with the LEC film. The quasi-one-dimensional probe tips allow insight into the electrochemical doping mechanism, without being disturbed by imperfections in the pre-deposited electrodes. Time-lapse fluorescence imaging has exhibited p- and n-doping of various shapes and shades, p-n junction electroluminescence, and the effects of bias reversal. The observed doping reaction kinetics suggests that n-doping is reaction-limited whereas p-doping is diffusion-limited. Furthermore, the electric potential and conductivity distributions of extremely large planar LECs have been mapped. The results show that the p-doping is more conductive than n-doping. More importantly, The results provide the first evidence that the p-n junction is indeed a graded one with decreasing conductivity and doping concentration from the electrode contact to the metallurgical junction. In addition, the optical beam induced current (OBIC) measurement has been explored to map the built-in electric field of extremely large planar LECs. This result clearly shows that a large electric field exists only around the junction region rather than in the electrode region. Moreover, the result confirms that the LEC electronic structure is a graded p-n junction. / Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2011-05-12 16:27:05.208

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

A fala privada, de acordo com Wertsch (1980), é definida como um diálogo que o indivíduo promove consigo mesmo e sua função recai na necessidade da autorregulação, autodirecionamento e autorreflexão. Os estudos sobre fala privada de crianças e adultos foram pesquisados por McCafferty (1994), Berk & Spuhl (1995), Fernyhough & Russell (1997), Krafft & Berk (1998), Winsler, Carlton, Barry (2000), Manfra & Winsler (2006), Smith (2007), Day & Smith (2013), entre outros. Entretanto, o estudo da fala privada não foi investigado pelas pesquisas de Língua Estrangeira para Crianças (LEC) no Brasil. Dessa forma, essa pesquisa de mestrado se insere na lacuna existente na falta de estudos sobre a fala privada como uma importante ferramenta cognitiva no processo de ensino-aprendizagem da Língua Inglesa (LI). Nos estudos do LEC e de ensino-aprendizagem de língua estrangeira em geral, a língua é considerada somente uma fonte de comunicação. O propósito desse estudo foi verificar como a fala privada ocorre, quais suas funções e frequência. Para tanto, nove crianças entre quatro e cinco anos de diferentes nacionalidades e línguas maternas em uma escola internacional foram gravadas durante as atividades de Circle Time e Phonics. De acordo com os dados coletados, na análise quantitativa, cada fala foi classificada em fala privada ou fala social com o propósito de descobrir qual criança produziu mais fala privada. Na análise qualitativa havia a necessidade de considerar o ambiente social da crianças para descrever quando a fala privada ocorreu, sua função e frequência. Por exemplo, existem crianças que são expostas a três ou mais línguas estrangeiras ao mesmo tempo em casa e na escola, algumas somente falam em inglês na escola e português em casa e outras falam inglês e português na escola e em casa. Os resultados mostraram que a fala privada foi importante na promoção da autorregulação durante o processo de ensino-aprendizagem das crianças analisadas. Ela desempenhou um papel importante no engajamento das crianças quando estavam aprendendo os sons e as palavras na língua inglesa. Além disso, a fala privada demonstrou uma participação efetiva das crianças durante as atividades mesmo aparentemente não sendo ouvidas pelo professor. / Private speech, according to Wertsch (1980), is defined as a private dialog that the individual promotes with himself and its function lies in the necessity of self-regulation, self-guidance and self-reflection. Private speech of children and adults has been extensively studied by McCafferty (1994), Berk & Spuhl (1995), Fernyhough & Russell (1997), Krafft & Berk (1998), Winsler, Carlton, Barry (2000), Manfra & Winsler (2006), Smith (2007), Day & Smith (2013) and others. In Brazilian research, a gap could be identified regarding the study of private speech in English as a Foreign Langague for Children (LEC) as an important cognitive tool for the teaching-learning process. In these Brazilian studies, language is considered only a source for communication. The purpose of this study was to verify how private speech occured, what was its function and frequency. For this reason, nine children between four and five years old from different nationalities in an international school were voice and video recorded during the activities of Circle Time and Phonics. According to the data collected, in the quantitative analysis, each speech was classified as private speech or social speech in order to count which child produced more private speech. In the qualitative analysis there was the necessity to consider the childs environment in order to describe when private speech occured, its function and frequency. For instance, there are children that are exposed to three or more languages at the same time at home and at school, some only speak English at school and Brazilian Portuguese at home and others speak English and Brazilian Portuguese at home and at school. The findings of this study showed that private speech was important for promoting self-regulation in the teaching-learning process of the children analysed. It also played an important role in children engajament when learning the sounds and the words in English. Besides that, private speech showed an effective involvement of the children during the activities even though they were not heard, apparently, by the teacher.

A fala privada, de acordo com Wertsch (1980), é definida como um diálogo que o indivíduo promove consigo mesmo e sua função recai na necessidade da autorregulação, autodirecionamento e autorreflexão. Os estudos sobre fala privada de crianças e adultos foram pesquisados por McCafferty (1994), Berk & Spuhl (1995), Fernyhough & Russell (1997), Krafft & Berk (1998), Winsler, Carlton, Barry (2000), Manfra & Winsler (2006), Smith (2007), Day & Smith (2013), entre outros. Entretanto, o estudo da fala privada não foi investigado pelas pesquisas de Língua Estrangeira para Crianças (LEC) no Brasil. Dessa forma, essa pesquisa de mestrado se insere na lacuna existente na falta de estudos sobre a fala privada como uma importante ferramenta cognitiva no processo de ensino-aprendizagem da Língua Inglesa (LI). Nos estudos do LEC e de ensino-aprendizagem de língua estrangeira em geral, a língua é considerada somente uma fonte de comunicação. O propósito desse estudo foi verificar como a fala privada ocorre, quais suas funções e frequência. Para tanto, nove crianças entre quatro e cinco anos de diferentes nacionalidades e línguas maternas em uma escola internacional foram gravadas durante as atividades de Circle Time e Phonics. De acordo com os dados coletados, na análise quantitativa, cada fala foi classificada em fala privada ou fala social com o propósito de descobrir qual criança produziu mais fala privada. Na análise qualitativa havia a necessidade de considerar o ambiente social da crianças para descrever quando a fala privada ocorreu, sua função e frequência. Por exemplo, existem crianças que são expostas a três ou mais línguas estrangeiras ao mesmo tempo em casa e na escola, algumas somente falam em inglês na escola e português em casa e outras falam inglês e português na escola e em casa. Os resultados mostraram que a fala privada foi importante na promoção da autorregulação durante o processo de ensino-aprendizagem das crianças analisadas. Ela desempenhou um papel importante no engajamento das crianças quando estavam aprendendo os sons e as palavras na língua inglesa. Além disso, a fala privada demonstrou uma participação efetiva das crianças durante as atividades mesmo aparentemente não sendo ouvidas pelo professor. / Private speech, according to Wertsch (1980), is defined as a private dialog that the individual promotes with himself and its function lies in the necessity of self-regulation, self-guidance and self-reflection. Private speech of children and adults has been extensively studied by McCafferty (1994), Berk & Spuhl (1995), Fernyhough & Russell (1997), Krafft & Berk (1998), Winsler, Carlton, Barry (2000), Manfra & Winsler (2006), Smith (2007), Day & Smith (2013) and others. In Brazilian research, a gap could be identified regarding the study of private speech in English as a Foreign Langague for Children (LEC) as an important cognitive tool for the teaching-learning process. In these Brazilian studies, language is considered only a source for communication. The purpose of this study was to verify how private speech occured, what was its function and frequency. For this reason, nine children between four and five years old from different nationalities in an international school were voice and video recorded during the activities of Circle Time and Phonics. According to the data collected, in the quantitative analysis, each speech was classified as private speech or social speech in order to count which child produced more private speech. In the qualitative analysis there was the necessity to consider the childs environment in order to describe when private speech occured, its function and frequency. For instance, there are children that are exposed to three or more languages at the same time at home and at school, some only speak English at school and Brazilian Portuguese at home and others speak English and Brazilian Portuguese at home and at school. The findings of this study showed that private speech was important for promoting self-regulation in the teaching-learning process of the children analysed. It also played an important role in children engajament when learning the sounds and the words in English. Besides that, private speech showed an effective involvement of the children during the activities even though they were not heard, apparently, by the teacher.

A polymer light-emitting electrochemical cell (LEC) is a solid-state polymer device operating according to in situ electrochemical doping and the formation of a light-emitting polymer p-n junction. This operating mechanism, however, has been the subject of much debate. Planar LECs with millimeter scale interelectrode spacings offer great advantages for directly observing the electrochemical doping process. Photoluminescence quenching and the formation of a light-emitting junction have been observed in planar polymer LECs, demonstrating the existence of electrochemical doping. The chemical potential difference between the p- and n-doped regions creates a built-in potential/electric field in the junction region, which can be probed by measuring the optical beam induced current (OBIC). This study utilizes a versatile and easy-to-use method of performing OBIC analysis. The OBIC and photoluminescence profiles of LECs have been simultaneously measured by scanning a focused light beam across large planar LECs that have been turned on and cooled to freeze the doping profile. The photoluminescence intensity undergoes a sharp transition between the p- and n-doped regions. The OBIC photocurrent is only observed in the transition region that is narrower than the width of the excitation beam, which is about 35 μm. The results depict a static planar polymer p-n junction with a built-in electric field pointing from n to p. The electrode interfaces do not produce a measurable photocurrent indicating ohmic contact. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2013-05-28 12:52:14.171

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Several methods have been developed for use in estimating the water quality loads associated with urban and agricultural landuses and practices. These include the use of sophisticated computer models, typically based on using pollutant loading and runoff functions, regression equations, load export coefficients (LECs), and event mean concentrations (EMCs). This research has examined the feasibility of using a simple EMC approach with the Kentucky Nutrient Model (KYNM). The thesis includes an extensive literature review of EMCs and a synthesis of recommended values for a range of typical urban and agricultural landuses. The thesis also includes an extensive literature review of potential BMPs along with a summary of the typical removal efficiencies and costs associated with each type of BMP. The research also explored the potential to use the results from multiple applications of site specific BMP models like the Source Loading and Management Model (WinSLAMM) in the development of general functional relationships that could then be used to evaluate BMP performance on a more site-specific basis. The developed EMC table and the associated BMP performance curves should provide valuable tools for use in better managing nutrient loads for urban and agricultural watersheds.

This thesis presents a comparative study between two silver nanoparticle inks that were deposited using a Drop-on-Demand (DoD) inkjet printer, aiming at finding a functional ink that can be used to print electrodes in Light-emitting Electrochemical Cells (LECs). To achieve this, a DoD inkjet printer was installed and an acquaintance with the printer was attained. Among the two inks, one was employed as received while the other was reformulated, and successful deposition of both the inks was observed. During the reformulation process, it was seen that the highly volatile tetrahydrofuran (THF) solvent can be used to improve the ink properties, in contrast to what is recommended. After that, the inks were deposited on UV-ozone treated glass substrates, sintered at an elevated temperature under ambient conditions, and their specific resistances and thicknesses were measured. Finally, the inks were used to print the anode in a structured sandwich-cell LEC. The performance comparison was conducted by observing the emitted light of the LECs. The results indicate that the reformulated ink performs better, probably due to the lower silver concentration that results in flatter surface, which in turn effectively alleviates shorts.

The cost of housing is rising disproportionately to income throughout the country. Alternative methods of providing low to moderate income housing are always being sought to offset the gap created by the varying rates of growth between the cost of housing and income. The purpose of this professional report is to examine the Limited Equity Cooperative (LEC) which by simple definition generally limits the resale value of member shares to maintain affordability over time. This report looks at the specifics the LEC to determine how it can by used to provide a viable solution to an overall shortage for low to moderate income households through an hypothetical test cased using 2007 data for the Metropolitan Boston area. / text