Enhanced performance and functionality of titanium dioxide papermaking pigments with controlled morphology and surface coating

Novel, tailored titanium dioxide pigments with controllable nanoscale morphological features were shown to significantly enhance the optical and strength properties of paper. The opacifying power of synthesized polycrystalline TiO2 particles in a cellulose matrix was found experimentally to be superior to that of a commercial rutile pigment, depending on the crystal structure of the synthesized particles. High aspect ratio polycrystalline rutile pigments composed of a linear linkage of several individual rutile crystals gave 6% more opacity than the commercial rutile pigment. Theoretical light scattering calculations using the T-Matrix Method showed the light scattering efficiency of linearly arranged polycrystalline rutile particles to depend on number and size of crystals composing the particle and confirmed the higher efficiency of the synthesized polycrystalline rutile pigments over commercial rutile. The opacifying power of hollow polycrystalline rutile particles was found experimentally to be superior to that of a commercial rutile pigment in a highly pressed bleached fiber matrix, depending on cavity size, while the opacifying power of silica-rutile titania core-shell particles was found comparable to commercial rutile at constant titania loading. The light scattering efficiency of titania core-shell particles was shown to be dependant on the light scattering efficiency of the core material. The overall particle shape and aspect ratio of titania core-shell and hollow nanoparticles were shown to be tunable by choosing an appropriate template and coating thickness in layer-by-layer or sol-gel templating synthesis. Inorganic-cellulose core-shell and hollow cellulose nanoparticles were prepared by self-encapsulation with regenerated cellulose via precipitation of cellulose in a polyacrylic acid hydrogel layer surrounding inorganic particle templates in 4-Methylmorpholine N-oxide (NMMO) monohydrate solution. This discrete encapsulation of inorganic pigments with a thin, uniform cellulose shell was found to increase the bondability improvement between the particles and a polysaccharide substrate. The crystallinity of several carbohydrate polymers was shown to significantly affect the bondability of encapsulated core-shell particles.Ph.D.Committee Chair: Yulin Deng; Committee Member: Arthur Ragauskas; Committee Member: Jeff Empie; Committee Member: Jeffery Hsieh; Committee Member: Preet Sing

POWER RELATION BETWEEN TECHNOLOGY AND INDIVIDUALS IN BLACK MIROR

Penelitian ini menganalisis rangkaian antologi Black Mirror yang menyajikan cerita tentang teknologi modern dan kehidupan manusia. Abad 21 merupakan era digital dimana penggunaan teknologi terus berkembang dan menjadi bagian penting dari kehidupan manusia, dampak dari teknologi sangat berpengaruh. Selain itu, kapabilitas teknologi dapat digunakan untuk mengerahkan kekuatan dan mempengaruhi individu dan dapat menimbulkan masalah. Penelitian ini menganalisis bagaimana teknologi modern dapat digunakan untuk menjalankan kekuasaan dan bagaimana hal tersebut dapat mempengaruhi karakter dalam cerita yang menghasilkan relasi kekuasaan antara teknologi dan individu. Teori relasi kekuasaan oleh Michel Foucault digunakan untuk mendeskripsikan bagaimana relasi kekuasaan antara teknologi dan individu digambarkan dalam rangkaian antologi Black Mirror dan bagaimana hal itu dijalankan. Penelitian ini menggunakan pendekatan sosiologis, sinyal nonverbal dan unsur intrinsik karakter serta penokohan sebagai cara mengidentifikasi dan menganalisis data. Dari penelitian ini ditemukan bahwa terdapat tiga relasi kuasa antara teknologi dan individu yang digambarkan dalam rangkaian tersebut

Pleasure and pedagogy: the consumption of DVD add-ons among Irish teenagers

This article addresses the issue of young people and media use in the digital age, more specifically the interconnection between new media pleasures and pedagogy as they relate to the consumption of DVD add-ons. Arguing against the view of new media as having predominantly detrimental effects on young people, the authors claim that new media can enable young people to develop media literacy skills and are of the view that media literacy strategies must be based on an understanding and legitimating of young people's use patterns and pleasures. The discussion is based on a pilot research project on the use patterns and pleasures of use with a sample of Irish teenagers. They found that DVDs were used predominantly in the home context, and that, while there was variability in use between the groups, overall they developed critical literacy skills and competences which were interwoven into their social life and projects of identity construction. The authors suggest that these findings could be used to develop DVDs and their add-on features as a learning resource in the more formal educational setting and they go on to outline the potential teaching benefits of their use across a range of pedagogical areas

Outdoor weathering performance parameters of exterior wood coating systems on tropical hardwood substrates

Wood coating research almost exclusively focuses on softwood as substrate despite the fact that coatings applied on tropical hardwoods show a different weathering behaviour. The objective of this study was to quantify the impact of wood substrate and coating type on the weathering behaviour of finished wooden joinery in outdoor exposure using a set of statistical methods. Therefore, a broad range of white opaque paints and mid-oak semi-transparent stains were used. The coatings were industrially applied on window frames made of frequently used commercial tropical hardwood species. The general appearance of the wood/coating systems was assessed visually using a rating scale that takes into account the anatomical characteristics of hardwood. For the evaluation, a required minimum exposure time of 2.5 years outdoor weathering for joinery in vertical position and facing south-west was determined. At 30 months best performances were recorded for waterborne alkyd primers with an acrylic topcoat when dry coating film was sufficiently thick. The dry layer thickness also affected the impact of the hiding power on the performance of the wood/coating system. Within hardwood species the degradation rate of coatings on species with a fine texture was the lowest. The significant influence of the substrate's texture on the weathering behaviour of coated hardwood stressed the need to evaluate the wood/coating system in total

Fast Ultrahigh-Density Writing of Low Conductivity Patterns on Semiconducting Polymers

The exceptional interest in improving the limitations of data storage, molecular electronics, and optoelectronics has promoted the development of an ever increasing number of techniques used to pattern polymers at micro and nanoscale. Most of them rely on Atomic Force Microscopy to thermally or electrostatically induce mass transport, thereby creating topographic features. Here we show that the mechanical interaction of the tip of the Atomic Force Microscope with the surface of a class of conjugate polymers produces a local increase of molecular disorder, inducing a localized lowering of the semiconductor conductivity, not associated to detectable modifications in the surface topography. This phenomenon allows for the swift production of low conductivity patterns on the polymer surface at an unprecedented speed exceeding 20 $\mu m s^{-1}$; paths have a resolution in the order of the tip size (20 nm) and are detected by a Conducting-Atomic Force Microscopy tip in the conductivity maps.Comment: 22 pages, 6 figures, published in Nature Communications as Article (8 pages

Avaliação e Melhoramento das Propriedades Anti-Soiling do Couro utilizado no Setor Automóvel

The present thesis was written at Stahl Holdings, B.V., in Waalwijk- Netherlands, in partial fulfillment of the requirements for the degree of master’s in chemical engineering of the Instituto Superior de Engenharia do Porto (ISEP). Stahl formulated the theme of the project, along with the interested company. The results obtained from this project contributed to increase Stahl’s internal knowledge and share it with the interested parties. This project started with the formulation of a coating system, followed by its application, consecutive tests and results evaluation. This thesis regards the study of the anti-soiling properties of a Clean Top, by evaluating the impregnation resistance to indigo and pen ink. The tests were conducted according to the dye ingress standard of a specific OEM, soiling of a specific OEM and European VDA, using a Martindale abrasion tester, a Crockmeter and a Datacolor TM’s hardware and software. There were four samples tested, being two of them brown, two beige, and one of each color had Clean Top has the anti-soiling coat. It was expected that the application of a last anti-soiling system would show better results to the soiling and dye ingress tests, and that its performance changed over time. The worst results were shown by the dye ingress standard and lighter colors. The application of Clean Top improves greatly the anti-soiling properties, with small to no variation over time.Esta tese foi escrita na Stahl Holdings, B.V., em Waalwijk- Holanda, como requisito parcial de finalização do mestrado em Engenharia Química, do Instituto Superior de Engenharia do Porto (ISEP). A Stahl planeou o projeto, juntamente com a empresa interessada. Os resultados obtidos contribuíram para aumentar o conhecimento interno da Stahl e partilhar com as partes interessadas. O projeto começou com a formulação de um acabamento, seguido pela sua aplicação, testes consecutivos e avaliação de resultados. Esta tese apresenta o estudo das propriedades anti-mancha de um topcoat, testando a resistência à penetração de indigo e tinta de caneta. Os testes forem realizados de acordo com as normas de impregnação de corante de uma montadora específica, manchamento de uma montadora específica e a norma europeia VDA, utilizando o equipamento de abrasão de Martindale, um crockmeter e o equipamento e programa da DatacolorTM. Era esperado que a aplicação de uma última camada de anti-soiling mostrasse resultados substancialmente melhores ao manchamento e à penetração de corante, e a sua performance mudasse com o tempo. Os piores resultados foram obtidos na norma do dye ingress e em cores claras. A aplicação do Clean Top melhora consideravelmente as propriedades anti-soiling, com pouca a nenhuma variação com o tempo

Dreaming of drams: Authenticity in Scottish whisky tourism as an expression of unresolved Habermasian rationalities

In this paper, the production of whisky tourism at both independently owned and corporately owned distilleries in Scotland is explored by focusing on four examples (Arran, Glengoyne, Glenturret and Bruichladdich). In particular, claims of authenticity and Scottishness of Scottish whiskies through commercial materials, case studies, website-forum discussions and 'independent' writing about such whisky are analysed. It is argued that the globalisation and commodification of whisky and whisky tourism, and the communicative backlash to these trends typified by the search for authenticity, is representative of a Habermasian struggle between two irreconcilable rationalities. This paper will demonstrate that the meaning and purpose of leisure can be understood through such explorations of the tension between the instrumentality of commodification and the freedom of individuals to locate their own leisure lives in the lifeworld that remains. © 2011 Taylor & Francis

Digital watermarking and novel security devices

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