The power of polymer wrapping:Selection of semiconducting carbon nanotubes, interaction mechanism, and optoelectronic devices

Koolstofnanobuizen hebben erg goede elektrische, mechanische en thermische eigenschappen. Als we de koolstofnanobuizen oplosbaar maken in organische oplosmiddelen, kunnen we deze nanobuisinkten gebruiken om elektronische apparaten te produceren, zoals zonnecellen en veldeffecttransistoren. Het maken van inkten van koolstofbuizen heeft ertoe geleid apparaten te kunnen vervaardigen op dezelfde manier als het drukken van kranten. Voor de productie van koolstofnanobuisinkten is het belangrijk dat de halfgeleidende koolstofnanobuizen gescheiden worden van de metalen koolstofnanobuizen om halfgeleidende koolstofnanobuizen met een hoge zuiverheid te verkrijgen. Tijdens mijn PhD project hebben we geconjugeerde polymeren gebruikt om deze scheiding uit te voeren. Onze resultaten laten zien welke polymeren beter binden aan de koolstofnanobuizen om de halfgeleidende nanobuizen te isoleren. Door de chemische structuren te analyseren met behulp van simulaties, hebben we het mechanisme van de interactie tussen het polymeer en de koolstofnanobuizen geïdentificeerd. We hebben ook ontdekt dat de toevoeging van specifieke additieven aan de inkt de controle over de polariteit van de transistors mogelijk maakt, wat belangrijk is voor de productie van verschillende technologische toepassingen.Van de halfgeleidende koolstofnanobuisinkten zijn we erin geslaagd om op maat gemaakte hoogwaardige veldeffecttransistoren te fabriceren. Dankzij deze kennis kunnen ze eenvoudiger en goedkoper worden geproduceerd. We hebben bovendien ontdekt dat een laag van halfgeleidende koolstofnanobuisinkt in een zonnecel de stabiliteit aanzienlijk verbetert, wat zou kunnen leiden tot een breder gebruik van zonnecellen als een bron van groene energie.Carbon nanotubes have great electrical, mechanical and thermal properties. If we make the carbon nanotubes soluble in organic solvents, we can use these nanotube inks to produce electronic devices such as solar cells and field effect transistors. The ability to make inks from carbon nanotubes allows the possibility of preparing electronic devices in a similar fashion as printing newspapers. For the production of carbon nanotube inks, it is important to ensure that the semiconducting carbon nanotubes are separated from the metallic carbon nanotubes to obtain semiconducting carbon nanotubes at a high purity. During my PhD project, we used conjugated polymers to perform this separation. Our results show which polymers interact better with the carbon nanotubes in order to isolate the semiconducting nanotubes. By analyzing the chemical structures using simulations, we identified the mechanism of the polymer-carbon nanotube interaction. We also found that the addition of specific additives to the ink allows the control of the polarity of the transistors, which is important for the production of different technological applications. From the semiconducting carbon nanotube inks, we succeeded to fabricate tailor-made high performing field effect transistors. This knowledge will help make them easier and cheaper to manufacture. We furthermore discovered that a layer of semiconducting carbon nanotube ink in a solar cell greatly improves the stability, which might lead to a broader use of solar cells as a source of green energy

O Relato de Jan Taccoen Van Zillebeke

UID/HIS/04666/2013 PEst-OE/HIS/UIOOIS/2011 - info ?Na Páscoa de 1514 passou por Lisboa, em viagem para Jerusalém, o nobre flamengo Jan Taccoen van Zillebeke. Nos nove dias em que permaneceu na cidade deu-se conta de variadas facetas da urbe, quer urbanísticas, como os principais edifícios e as características das habitações e vias de comunicação, quer económicas e sociais, como o grande número de escravos, o uso de animais exóticos pela corte e a atitude perante o adultério, aos quais se referiu no relato que, no regresso ao país natal, redigiu sobre o conjunto da sua viagem. Na presente edição publica-se a parte referente a Lisboa dessa relação, e incluem-se três outros textos de enquadramento histórico, nomeadamente de dois historiadores belgas interessados neste tema, Eddy Stols e Stijn Manhaeghe.publishersversionpublishe

Factores motivacionales que influyen en los jóvenes para la elección de la carrera de estomatología - Trujillo 2015

El presente estudio tuvo como propósito, determinar los factores motivacionales que influyen en los jóvenes, para la elección de la carrera de Estomatología - Trujillo 2015. El estudio prospectivo, transversal, descriptivo y observacional, estuvo conformada por 197 alumnos de primero y segundo año de estomatología de la Universidad Privada Antenor Orrego 2015 que aceptaron participar en el estudio. Los factores motivacionales fueron evaluados empleando un instrumento elaborado especialmente para el presente estudio, previamente validado mediante juicio de expertos, y con muy buena confiabilidad (Kuder- Richardson 0.84), lo cual se obtuvo mediante un estudio piloto con 30 unidades de análisis. Se realizó un análisis estadístico empleando el programa estadístico IBM SPSS Statistics 22.0 (IBM,Armonk,NY,USA), los datos fueron presentados en tablas de doble entrada y/o graficos expresados en números y porcentajes. Los resultados mostraron que, el factor motivacional sociocultural que más influyó fue, porque le permitirá brindar apoyo a la sociedad, con un 97%; con mayor tendencia en el sexo femenino y el factor personal de mayor influencia fue, porque le ayudará a alcanzar sus metas propuestas, mostrando 97%; con mayor tendencia en el sexo masculino; concluyendo que, los estudiantes de estomatología, de la Universidad Privada Antenor Orrego, eligieron estudiar la carrera de estomatología, porque tienen vocación de servicio a la sociedad, además de tener metas personales que cumplir."The present study was to determine the motivational factors influence young people for career choice of Stomatology - 2015 Trujillo . The prospective, transversal , descriptive and observational study consisted of 197 students from first and second year of Stomatology of the Private University Antenor Orrego 2015 who agreed to freely participate in the study . Motivational factors were evaluated using a tool developed specifically for this study , previously validated by expert opinion , and with very good reliability ( Richardson Kuder- 0.84 ) , which was obtained through a pilot study with 30 units of analysis. Statistical analysis using statistical program SPSS Statistics 22.0 (IBM, Armonk , NY , USA ) , data were presented in two-way tables and / or graphics , expressed in numbers and percentages are made . The results showed that the sociocultural motivational factor was most influential, because it will allow the company to support, with 97%; with more likely in females and the personal factor was most influential, because it will help them achieve their targets, showing 97%; with more likely in males; concluding that students of dentistry, the Private University Antenor Orrego, chose to study the career of dentistry, because they have a vocation of service to society, as well as having personal goals to fulfill. "Tesi

Analysis of the variables that contribute to self-organization for the management of family lands in the Yánesha Native Community Santa Rosa de Chuchurras, Pasco, Peru

This research analyzed the variables that contribute to self-organization within the general framework for analysing the sustainability of socioecological systems (SES). In our case study, a correlation analysis showed that 80% of the variables contribute to the self-organization of the community in relation to the key resource: family land. There was evidence of land use transition, initially dependent on agrosilvopastoral system, towards diverse economic activities and with it also the inclusion of informal norms (institutional bricolage). These changes stem from two circumstances that threaten community organization. The first is linked to the absence of legal recognition of family lands by the Peruvian State, despite the prioritization of family economic activities over collective actions. The second is the precarious road connectivity that makes exporting difficult, slowing down production and the quality of their supply. If these two circumstances were addressed through public policies: a) the emigration of the community's younger population would be reduced; b) foreign investment would be attractive in this community; c) would increase the flow of energy and information between the community and its environment improving social capital and trust; and finally, d) uncertainty would be reduced, strengthening community self-organization

The Glass House

A collaboration of Architects and Architectural Engineers to design a unique depiction of the 50x50 Glass House with Miesian Architectural appeal

Sinterização por aquecimento rápido com Loop temperatura/posição

Mestrado em Engenharia MecânicaDurante a sinterização de sistemas policristalinos ocorrem processos às partículas do material entre os quais densificação, engrossamento do grão, controlo da porosidade, segregação das partículas entre outros. Estes processos resultam num de três transportes de mecanismos condensação/evaporação na superfície, pela difusão nos limites do grão e pela difusão da látice. A microestrutura final pode ser modificada ao forçar um específico fenómeno a ser predominante sobre os restantes durante o processo de sinterização. Por exemplo, o processo de sinterização por aquecimento rápido representa um procedimento onde o perfil Temperatura-Tempo (T-t) é alterado rapidamente para atingir uma Temperatura (T) onde a densificação predominante sobre o crescimento do grão. Desta maneira é possível obter um tamanho de grão mínimo mantendo no entanto um grau de densificação elevado em materiais policristalinos. O trabalho aqui apresentado irá projectar e construir um dispositivo mecânico que permita introduzir amostras cerâmicas dentro de um forno com uma rampa de aquecimento controlada, enquanto tendo um feedback constante da posição e temperatura das amostras.The processes that occur during sintering of polycrystalline systems, are those of particle necking, densification, grain coarsening, porosity control, and segregation. These processes result from three mass transport mechanisms: surface condensation/evaporation, grain boundary diffusion, and lattice diffusion. The final microstructure can be varied by forcing a specific phenomenon to predominate over the others during the sintering process. For example, the fast-firing process represents a sintering procedure where the temperature– time (T–t) profile is altered to rapidly reach the T regime where densification dominates over grain growth. In this way, a small grain size can be maintained while still offering a high densification of polycrystalline materials. Therefore, the current work will design and build a mechanical device, to introduce ceramic samples into a furnace at a controlled ramp rate, with an instantaneous temperature/motion feedback loop

Azul, Amarillo, Rojo

My most recent body of work was produced out of the pleasure of exploring pure formal and processual painting. In this text—divided by sections titled like a traditional opera to highlight the mise-en-scene quality of my artwork—the reader will find clues about the context, inspirations, and desires that led to my current practice, such as my ambivalent condition as an immigrant, my exposure to post-conceptual abstraction embodied in Christopher Wool’s provocative oeuvre, and my interest in offering the viewer the experience of what I call “an aesthetic interrogation.” l have privileged in this thesis my own voice and character with the hope to articulate a sincere and individual approach to art-making that not only legitimizes my practice as a contemporary artist, but makes it more human, universal, timeless, and trivial