Fabrication of Highly Reflective Bottom Electrodes for Inverted Top-emission OLED Applications

The demand for more air-stable and high resolution devices are opening the space for inverted top-emission OLEDs in the displays market. To realize these high-performance devices, a combination of a highly reflective bottom electrode with an efficient electron injection layer is essential to achieve high luminance efficiency and low driving voltage, respectively. The aim of this thesis was to develop a new highly reflective stack and a corresponding method for high resolution patterning to enable future top-emission iOLED applications. First, the deposition methods for a multilayer reflective stack were developed. Initially, a structure using silver as reflective thin film and ITZO as electron injection layer was used. Reflective and transmission measurements together with optical simulation were executed to optimize the thickness of each sputtered thin film in the final stack. During the development, the oxidation of Ag prevented the high reflectivity of the layer. To mitigate this issue, a new stack with an ITO interlayer between Ag and ITZO layers was created to prevent silver oxidation from the ITZO deposition process. Finally, optimized samples with a configuration of Ag(50 nm)/ITO(5 nm)/ITZO(80 nm) were demonstrated with a reflectivity > 78% in the visible range. To obtain high resolution feature sizes on the developed stack, the photolithography recipe to pattern the multilayer stacks with resolution down to 5um was also developed. During this project, different liquid etchants were tested to pattern the structure in two wet-etching steps. The quality of the etch were analysed by atomic force microscope and optical microscope images. Images of individual ITZO layers demonstrated the importance of using Ti Prime before photoresist spin-coating to improve the quality of the etch. At the end, cross-sections of the full stack showed that well-defined hills and valleys were achieved when samples were dipped in 10% mixed acid etchant for 30sec at RT followed by a dip in 75% PWES solution for 5 sec at 45C

The impact of unemployment and income on delinquency and default in the USA

This investigation focuses on the impact of unemployment and income on delinquency and default rates. Auto loans, credit cards, mortgages and student loans in the United States of America (USA) were used to perform this analysis Panel data covered the District of Columbia and the 50 states of the USA with annual data from 2003 to 2018. A probit model was used and compared with a linear model for each type of loan. The innovation of this study is the introduction of the spread of unemployment variable to study the effect of unemployment on these loans’ delinquency rates. This study finds empirical evidence that the spread of unemployment increases delinquency and default on credit, and the median household income decreases the delinquency and default in the USA. The results demonstrate that consumer sentiment impacts negatively on delinquency and default, as does the S&P 500 index. To prevent the effects of delinquency and default on the economy, the US government should promote measures to create more jobs, reducing unemployment and increasing household income.Esta investigação estuda o impacto do desemprego e do rendimento na taxa de delinquência e no incumprimento dos créditos americanos. Para fazer esta análise foram utilizados os empréstimos automóveis, os cartões de crédito, as hipotecas e os empréstimos para estudantes, utilizando dados em painel para o District of Columbia e para os 50 estados dos Estados Unidos da América (EUA). Para a realização deste estudo foram utilizados dados anuais de 2003 a 2018, aplicando um modelo probit, que será comparado com um modelo linear para cada tipo de empréstimo. A inovação deste estudo é a introdução do spread do desemprego para estudar o efeito do desemprego nas taxas de delinquência destes empréstimos. Este estudo encontra evidências empíricas de que o spread do desemprego aumenta a delinquência e o incumprimento dos créditos e o rendimento médio das famílias diminui a delinquência e o incumprimento dos créditos nos EUA. Os resultados demonstram que o sentimento do consumidor faz com que a taxa de delinquência e o incumprimento diminuam e o índice S&P 500 faz com que a taxa de delinquência e o incumprimento diminuam. Para evitar os efeitos da delinquência e do incumprimento na economia, o governo dos EUA deve criar medidas com o intuito de gerar mais empregos, reduzindo assim o desemprego e aumentando o rendimento das famílias

Toxicological effects of TiO2 nanoparticles in two freshwater species: carassius auratus and corbicula fluminea

Titanium dioxide (TiO2) nanoparticles (NPs) have a widespread use, from industrial applications to consumer products. The increasing use of nanomaterials can lead to significant releases of NPs into environment and the aquatic system is commonly the ultimate recipient for NPs. However, the impact and potential detrimental effects of NPs to aquatic biota remains unclear. In this context, the aim of the present work is to evaluate the toxicity of the TiO2 NPs exposure in two freshwater species (Carassius auratus and Corbicula fluminae). Organisms were exposed to suspensions of TiO2 NPs (±21 nm) within a range of concentrations from 0.01 to 800 mg TiO2/L and sampled for enzymatic and histological analysis after periods of 7, 14 and 21 days. Lipid peroxidation, superoxide dismutase, catalase and glutathione-s-transferase activity were determined in order to evaluate the response to oxidative stress. Tissues from target organs were analyzed by optical and electron microscopy and x-ray elemental analyses allowed detecting the presence of TiO2. The exposure to TiO2 NPs in aquatic suspensions was not lethal for C. auratus, but significant mortality rates were found for C. fluminea. Results show that TiO2 NPs causes toxicity involving oxidative stress, increasing lipid peroxidation and inducing significant variations of the antioxidant activity in the exposed organisms compared to controls and over exposure time. Histological pathologies were observed in C. auratus gills, liver and intestine and in C. fluminea digestive gland. NPs in suspension are ingested by organisms, resulting in the accumulation of TiO2 NPs agglomerates inside C. auratus intestinal lumen. Cellular internalization of TiO2 NPs was confirmed in cells from fish gills. The results suggest that, a potential risk to the aquatic biota exist related to the TiO2 NPs release to the aquatic environment. The environmental impact of the NPs is a matter of concern and despite an increase of studies of nanosized-TiO2 effects, the precise mechanisms of toxicity of this and other metal NPs remain unclear.As nanopartículas (NPs) de dióxido de titânio (TiO2) têm uma vasta utilização, desde aplicações industriais a produtos para os consumidores. O uso crescente de nanomateriais pode levar à entrada de quantidades significativas de NPs no meio ambiente, sendo o meio aquático muitas vezes o seu destino final. Porém, o impacto e possíveis efeitos nocivos das NPs para o biota aquático ainda não estão totalmente clarificados. Neste contexto, este trabalho pretende avaliar a toxicidade de NPs de TiO2 em duas espécies de organismos de água doce (Carassius auratus e Corbicula fluminae). Os organismos foram expostos a suspensões de NPs de TiO2 (±21 nm) com concentrações desde 0.01 a 800 mg TiO2/L e processados para a realização de análises enzimáticas e histológicas após períodos de 7, 14 e 21 dias. Foi determinada a actividade enzimática da superóxido dismutase, catalase e glutationa-s-tranferase e o grau de peroxidação lipídica, a fim de avaliar a resposta ao stress oxidativo. Os tecidos de órgãos alvo previamente seleccionados de acordo com a sua importância fisiológica foram observados através de microscopia óptica e electrónica e a presença de TiO2 foi determinada através de análise elementar de raio x. A exposição dos organismos a suspensões de NPs de TiO2 não foi letal para os peixes da espécie C. auratus, mas níveis de mortalidade significativos ocorreram nos bivalves da espécie C. fluminae. Os resultados demonstram que as NPs de TiO2 podem causar toxicidade sub-letal envolvendo stress oxidativo, aumentando a peroxidação lipídica e induzindo variações significativas da actividade antioxidante comparativamente aos controlos e ao longo dos períodos de exposição. Foram observadas alterações histológicas nas branquias, fígado e intestino dos peixes e na glândula digestiva dos bivalves. Verificou-se que as NPs presentes em suspensão foram ingeridas pelos organismos, o que resulta na acumulação de aglomerados de NPs dentro do lúmen intestinal dos peixes. Confirmou-se ainda a ocorrência de internalização celular de NPs de TiO2, especificamente nas células do tecido branquial dos peixes. Os resultados obtidos sugerem que existe um potencial risco para o biota aquático, relacionado com a entrada das NPs de TiO2 no ambiente aquático. O impacto ambiental das NPs é uma questão de enorme relevância e apesar de se observar um aumento dos estudos sobre os efeitos das NPs de TiO2, os mecanismos de toxicidade destas e de outras NPs metálicas permanecem por esclarecer

Task interference effects in prospective memory

Prospective memory (PM), or remembering to remember, is biq it s i p pl ’s liv s a d PM misses might represent around half of daily memory failures according to recent research. In this thesis, several intention-related factors were investigated in order to clarify and elaborate our understanding of the effects of working memory (WM) and cognitive aging on prospective remembering, increase theoretical clarity regarding the dynamics of the monitoring processes in PM tasks, and investigate the interplay between two qualitatively different PM retrieval processes (i.e., spontaneous retrieval and monitoring). The overall approach was to examine how holding a particular intention affected ongoing task performance in a series of specifically devised laboratory studies of PM. The main findings of this thesis can be summarized as follows: First, encountering intention-related information boosted nonfocal PM performance for low, but not high, WM young adults, and did so without any additional cost to ongoing task performance (Experiment 1). Second, presenting intention-related information as distractor items improved PM performance for older, but not young adults (Experiments 2 and 3). The benefit was most likely due to distractor lures enhancing the salience of the target events and triggering spontaneous retrieval of the intention, or alternatively (or additionally), triggering (functional) monitoring in close proximity to the target events (Experiment 2). Third, practicing the ongoing activity prior to encoding the PM task enhanced nonfocal target detection for high WM young adults, but not for low WM young adults and older adults; practice probably allowed individuals to encode a more elaborate and detailed representation of the PM task (Experiment 4). Fourth, explicit information about target-defining features led to trial-by-trial modulations in task interference as a function of stimulus relevance for the nonfocal PM task. The effect was observed when relevant and irrelevant stimuli varied at random with no cuing (Experiments 5 and 6) and when presentation was blocked (Experiment 5), and was most likely associated with the action of top-down attentional control. Fifth, implicit information about the PM task demands also aff ct d pa ticipa ts’ ff t a d s cc ss i the PM task. Moreover, experience with the PM targets triggered local changes in attention allocation when actual demands were higher than expected (Experiment 7). And sixth, target repetition within a set boosted PM performance by stimulating retrieval through spontaneous retrieval processes, and optimized performance relative to when retrieval relied mostly on monitoring processes alone (Experiment 8). In summary, the present work uncovered several factors that have the potential to boost prospective remembering, as well as influence the extent to which monitoring processes are engaged and/or the type of processing required to support PM retrieval

When distraction holds relevance : a prospective memory benefit for older adults

Evidence is accumulating to show that age-related increases in susceptibility to distracting information can benefit older more than young adults in several cognitive tasks. Here we focus on prospective memory (i.e., remembering to carry out future intentions) and examine the effect of presenting distracting information that is intention-related as a function of age. Young and older adults performed an ongoing 1-back working memory task to a rapid stream of pictures superimposed with to-be-ignored letter strings. Participants were additionally instructed to respond to target pictures (namely, animals) and, for half of the participants, some strings prior to the targets were intention-related words (i.e., animals). Results showed that presenting intention-related distracting information during the ongoing task was particularly advantageous for target detection in older compared to young adults. Moreover, a prospective memory benefit was observed even for older adults who showed no explicit memory for the target distracter words. We speculate that intention-related distracter information enhanced the accessibility of the prospective memory task and suggest that when distracting information holds relevance to intentions it can serve a compensatory role in prospective remembering in older adults

O papel mediador da relação líder-membro na relação entre o estilo de liderança transformacional e a coesão da equipa : um estudo com equipas em contexto militar

Tese de mestrado, Psicologia (Psicologia dos Recursos Humanos, do Trabalho e das Organizações), Universidade de Lisboa, Faculdade de Psicologia, 2010Um mecanismo pelo qual as organizações aumentam a sua capacidade de adaptação é através da implementação de equipas (Burke, Stagl, Salas, Pierce & Kendall, 2006). Alguns autores defendem que o desempenho destas equipas pode ser optimizado com a existência de um líder eficaz (e.g. Hackman & Wageman, 2005a) e com a coesão da equipa (Cohen & Bailey, 1997). O presente estudo visa explorar a o estilo de liderança transformacional e a coesão da equipa. As hipóteses deste estudo focam-se no papel do estilo de liderança transformacional na coesão da equipa e no papel da LMX como mediadora desta relação. Recorrendo a uma amostra de 66 soldados recrutas da Ota, mediu-se a coesão da equipa (Riordan & Weatherly, 1999), a LMX (Scandura e Graen, 1984) e o estilo de liderança transformacional (Yukl, 1999). Os resultados suportam as hipóteses formuladas.One mechanism by which organizations are improving their ability to adapt is through the implementation of teams (Burke, Stagl, Salas, Pierce & Kendall, 2006). Some authors argue that the performance of these teams can be optimized with the existence of an effective leader (e.g. Hackman & Wageman, 2005a) and with teams’ cohesiveness (Cohen & Bailey, 1997). The present study explores the transformational leadership style and team’s cohesiveness. The hypothesis of this study focused on the role of transformational leadership style on team’s cohesiveness and the role of LMX as a mediator of this relationship. Using a sample of 66 recruits soldiers from Ota, we measured teams’ cohesiveness (Riordan & Weatherly, 1999), the LMX (Scandura e Graen, 1984) and the transformational leadership style (Yukl, 1999). The results support our hypothesis

Exploring the crosstalk between mesenchymal stem cells and endothelial cells in bone tissue engineering

Tese de programa doutoral. Engenharia Biomédica. Universidade do Porto. Faculdade de Engenharia. 201

Vitimização e delinquência

A delinquência juvenil é actualmente um problema vasto e multidimensional que afecta diversos contextos sociais um pouco por todo o mundo. A crescente evolução deste fenómeno tem vindo a despoletar um preocupante sentimento de insegurança a par de uma consciente necessidade de combate e prevenção dos comportamentos delinquentes por parte das crianças e jovens. São inúmeras as causas que estão na raiz da delinquência juvenil e também a vitimização pode estar associada a este tipo de comportamentos. Neste sentido, o estudo destes fenómenos tem ganho especial importância, em grande parte devido à aparente incapacidade de resposta e combate ao problema da criminalidade praticada por crianças e jovens. Os objectivos deste trabalho passam por dar uma visão do papel da Guarda Nacional Republicana no âmbito da Delinquência Juvenil bem como da sua cooperação com instituições civis na prevenção e diminuição deste problema. Para tal, foram aplicadas entrevistas a comandantes de Destacamentos Territoriais, por serem estes quem estabelece, na maior parte das vezes, um contacto mais directo com as outras entidades e instituições. Em conclusão, com este humilde trabalho de investigação, verificou-se que o reforço do patrulhamento junto das escolas (onde ocorrem a maioria dos delitos), bem como as acções de sensibilização junto dos jovens, familiares e educadores, tem contribuído para a prevenção de condutas delinquentes. Além disso, também a cooperação entre as forças de segurança e entidades civis constitui uma mais-valia no combate a este fenómeno.Abstract Youth delinquency has become a vast and multidimensional problem affecting several social networks all over the world. The growing evolution of this phenomenon has been developing a troublesome feeling of insecurity and also a conscientious necessity to fight and prevent delinquent behavior from children and youth. There are innumerous causes for youth delinquency, and victimization can also be associated with this kind of behavior. For this reason, the study of this phenomenon has gained special importance, mainly because of the incapacity to respond and fight the problem of this kind of criminality. The objectives of this work are to review the role of Guarda Nacional Republicana (Republican National Guard) concerning Youth Delinquency as well as its cooperation with civil institutions in the prevention and diminishing of this problem. With that purpose in mind, interviews to the commanders of some territorial deployments were made, because they are the ones who, most of the times, establish a more direct contact with the entities and institutions. In conclusion, with this humble research work it was verified that patrol reinforcement in schools (where the majority of the felonies occur), as well as awareness-raising actions with youth, family and educators has contributed to the prevention of delinquent conducts. Furthermore, the cooperation between law enforcement agents and civil entities also becomes a valuable asset in the combat of this phenomenon

Estudo da relação multidimensional entre severidade da dor, impacto nas atividades da vida diária e presença de fatores psicossociais desajustados, em indivíduos com dor lombar crónica.

Relatório do Projeto de Investigação apresentado para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Fisioterapia, área de especialização em Fisioterapia em Condições Músculo- EsqueléticasIntrodução: A incapacidade funcional e/ou a interferência nas atividades da vida diária nos utentes com DLC tem sido associada à intensidade da dor. Recentemente, tem sido colocada a hipótese que maiores níveis de intensidade da dor e maiores limitações na capacidade de realizar as atividades da vida diária estão igualmente associados a fatores psicossociais (sintomas depressivos, catastrofização e cinesiofobia). Objetivo: Caracterizar o impacto funcional e psicossocial da DLC, considerando os domínios recomendados pela National Institute of Health Task force on Research Standards for Chronic Low Back Pain, e explorar a relação destes domínios entre si, em utentes com DLC de origem não específica. Adicionalmente, investigar se quem reporta dor severa tem maior impacto nas atividades da vida diária e se isso se relaciona com fatores psicossociais. Metodologia: Amostra por conveniência de 120 utentes com DLC não específica, avaliados de forma transversal, aplicados o questionário sócio-demográfico e clínico, Escala Numérica da Dor (END) e Quebec Back Pain Disability Scale-portuguesa (QBPDS-PT). Resultados: Cerca de metade dos participantes referiram interferência da DLC nas atividades do dia-a-dia (40,0%, n=48), atividades em casa (45,0%, n=54) e tarefas domésticas (46,7%, n=56). Na participação social a interferência foi menor (29,2%, n=35). O valor médio de incapacidade funcional foi 32,38 (±17,42) na QBPDS-PT. A intensidade média da dor foi de 5,01 (± 2,34) na END. 30,8% dos participantes apresentou sintomas depressivos, 37,5% apresentou catastrofização e 23,3% apresentou cinesiofobia. Verificaram-se correlações significativas (p<0,01) entre as variáveis que definem o impacto da DLC (intensidade da dor e incapacidade funcional). A severidade da dor, catastrofização e sintomas depressivos associaram-se com a interferência nas atividades do dia-a-dia, atividades em casa, participação social e tarefas domésticas. A cinesiofobia apenas se associou com a interferência das atividades em casa. Conclusão: Utentes que reportam dor severa têm maior interferência nas atividades do dia-a-dia, atividades em casa, nas tarefas domésticas e na participação social, sendo que essa relação é moderada pela presença de fatores psicossociais, nomeadamente, a catastrofização e a presença de sintomas depressivosIntroduction: Functional disability and/or interference in activities of daily living in patients with CLBP has been associated to pain intensity. Newly, it has been hypothesized that higher levels of pain intensity and greater limitations in the ability to perform activities of daily living are associated to psychosocial factors (depressive symptoms, catastrophizing and kinesiophobia). Aim: Characterize the functional and psychosocial impact of CLBP considering the domains recommended by the National Institute of Health Task force on Research Standards for Chronic Low Back Pain and explore the relation between this domain, in patients with nonspecific CLBP. Additionally, investigate whether those who report severe pain have higher impact on activities of daily living and if this is related with psychosocial factors. Methodology: Convenience sample of 120 nonspecific CLBP patients, cross sectional assessed using Numeric Rating Scale (NRS) and Quebec Back Pain Disability Scale (QBPDS-PT). Results: About half of the participants reported CLBP interference in activities of daily living (40,0%, n=48), home activities (45,0%, n=54) and household tasks (46,7%, n=56). In social participation, the interference was minor (29,2%, n=35). The mean value for functional disability was 32,38 (±17,42) in QBPDS-PT. Mean pain intensity was 5,01 (± 2,34) in NRS. 30,8% of the participants had depressive symptoms, 37,5% had catastrophizing, and 23,3% had kinesiophobia. There were significant correlations (p<0,01) between the variables that defined the CLPD impact (pain intensity and functional disability). Severity of pain, catastrophizing and depressive symptoms were associated with interference in activities of daily living, home activities, social participation and household tasks. Kinesiophobia was only associated with interference with home activities. Conclusions: Patients who report severe pain have greater interference with activities of daily living, home activities and household tasks and social participation, this relation is moderated by the presence of psychosocial factors: catastrophizing and depressive symptoms

Do outro lado das janelas: o Imaginário cultural da RTP Internacional

Esta dissertação visa o estudo do género cultural na RTP Internacional através da análise dos alinhamentos da sua emissão ao longo de oito anos. O objetivo primário é verificar a existência de conteúdos culturais na emissão deste serviço de programas tendo em conta as premissas da sua missão identitária e cultural no contexto das emissões internacionais, aspetos igualmente tratados. Através do sistema de classificação de programas utilizado pela RTP, autonomizaram-se os programas do género cultural e avaliou-se a sua expressão quantitativa através da sua frequência e duração. Os resultados demonstram que há uma grande diferença entre um canal que se apresenta vocacionado para assegurar e promover a cultura de um país e os programas que nele são emitidos com relação à própria cultura. No entanto, a RTP Internacional tem um papel muito específico no panorama das televisões internacionais junto do seu público-alvo, comunidades portuguesas e países de expressão portuguesa e, nesse sentido, é um serviço cuja relevância deve ser mais trabalhada.This dissertation focuses on the study of the cultural genre in RTP Internacional trough the analysis of its broadcast alignments in eight years. The primary purpose is to verify the existence of cultural programmes in its broadcast having in mind the basis of its identitarian and cultural mission in the transnational broadcast context, equally approached aspects. Starting from the audiovisual programmes classification system used by RTP, the cultural genre programmes were assorted and its quantitative expression was evaluated by their frequency and duration. The results show that there is a great difference between a channel that presents itself designed to ensure and promote a country’s culture and the broadcasted programmes related to that culture. Nevertheless, RTP International has a very specific role in the transnational broadcast panorama by its target-public, the Portuguese communities and Portuguese language countries and, in that sense, is a service which relevance must be better addressed