Abstract The aim of the deinking process is to produce deinked pulp from recovered papers (RCPs) with sufficient brightness and cleanliness to fulfil the quality requirements set by the paper grade to be produced. Due to the excessive production costs and material losses of modern deinking processes, there is a need to simplify deinking lines. A prerequisite for this action is that ink content bound to fibres, dirt content and ink fragmentation are minimised in the pulping stage. Thus, it is important to recognise the factors affecting ink behaviour in pulping, to search for new ways to improve ink detachment from RCPs in pulping and to search pulping methods that could efficiently process RCPs printed with various inks. The aim of this thesis was to obtain new information on how the environmental conditions that prevail during the storage and transportation of RCPs affect ink behaviour in subsequent pulping and to find out whether there is further potential to decrease ink content bound to fibres, not only by treating recovered papers chemically before the actual pulping process, but also by removing the detached ink particles during the pulping process. The results show that if some RCPs are very moist and exposed to high temperatures for a reasonable time before the pulping process, the problems in releasing ink from the fibres in pulping become more pronounced and the pulp is dirtier compared to pulp from RCPs that are thermally aged but dry. Properly wetting some RCPs with conventional alkaline deinking chemicals in suitable conditions ahead of the pulping process reduces the ink content that remains bound to the fibres after the pulping process. The efficiency of the pre-wetting treatment in aiding ink detachment from fibres in subsequent pulping is highly dependent on the alkalinity, temperature and duration of the treatment. Semi-continuous ink removal during the pulping process offers the possibility to continue defibering, ink detachment from fibres and dirt fragmentation in pulping without fear of ink redeposition into or onto the fibres, thus resulting in fully disintegrated pulp with lower ink content bound to fibres than in conventional pulping. This enables efficiently simultaneous processing of, for example, papers printed with water-based inks and toners. / Tiivistelmä Siistausprosessin tavoitteena on tuottaa keräyspapereista valmistettua vaaleaa ja puhdasta massaa, jota voidaan käyttää uusien paperituotteiden valmistamiseen. Siistausprosesseja pyritään yksinkertaistamaan nykyisten monimutkaisten prosessien korkeiden tuotantokustannusten ja materiaalitappioiden vuoksi. Eräs edellytys siistausprosessien yksinkertaistamiselle on, että kuiduissa kiinni olevan musteen pitoisuus, massan likapitoisuus ja musteen liiallinen pilkkoutuminen minimoidaan siistausprosessin ensimmäisessä vaiheessa, pulpperoinnissa. Täten on tärkeää tunnistaa musteen käyttäytymiseen pulpperoinnissa vaikuttavat tekijät, etsiä uusia mahdollisuuksia parantaa musteen irrotusta keräyspapereista sekä kehittää pulpperointimenetelmiä, joilla voitaisiin prosessoida tehokkaasti eri painomenetelmillä painettuja papereita. Tämän työn tavoitteena oli saada uutta tietoa siitä miten ympäristöolosuhteet, joille keräyspaperit voivat altistua varastoinnin ja kuljetuksen aikana, vaikuttavat musteen käyttäytymiseen pulpperoinnissa. Lisäksi tavoitteena oli selvittää voitaisiinko kuituihin kiinni jääneen musteen pitoisuutta vähentää esiliottamalla keräyspapereita sopivissa kemiallisissa olosuhteissa ennen pulpperointia ja poistamalla irronneet mustepartikkelit massan seasta pulpperoinnin aikana. Tulokset osoittavat, että jos tietyt keräyspaperit ovat erittäin kosteita ja altistuvat korkealle lämpötilalle riittävän pitkän ajan ennen pulpperointia, tulee musteen irrottaminen kuiduista pulpperoinnissa vaikeammaksi ja tuotettu massa likaisemmaksi, kuin sellaisista keräyspapereista, jotka ovat altistuneet kuivina korkealle lämpötilalle. Kuituihin kiinnittyneen musteen pitoisuutta voidaan vähentää esiliottamalla tiettyjä keräyspapereita alkalisilla siistauskemikaaleilla sopivissa olosuhteissa ennen pulpperointia. Esiliotuksen kyky parantaa musteen irrotusta kuiduista pulpperoinnissa riippuu voimakkaasti esiliotusvaiheen alkalisuudesta, lämpötilasta ja kestosta. Kun irronneet mikroskooppiset mustepartikkelit poistetaan massasta useassa vaiheessa pulpperoinnin aikana, voidaan paperin kuidutusta, musteen irrottamista kuiduista ja likapilkkujen hajottamista jatkaa ilman että haitallista musteen takaisin kiinnittymistä kuituihin tapahtuu. Tämä mahdollistaa esimerkiksi vesipohjaisten musteiden ja lasertulosteiden samanaikaisen prosessoinnin.

La qualité d'impression est une notion difficile à maîtriser. L'œil est souvent utilisé en industrie comme outil permettant de juger la qualité d'un film polymère imprimé. Afin d'atteindre un niveau supérieur de qualité, il est nécessaire de trouver un moyen pour quantifier la qualité d'impression, et ainsi permettre d'atteindre soit une qualité dite « point par point », soit une qualité dite « all-over ». Plusieurs éléments sont nécessaires à cette quantification : une image en microscopie optique de l'échantillon, ainsi qu'une valeur d'intensité moyenne et d'homogénéité de couleur, que l'on obtient grâce à un rugosimètre confocal. Ainsi nous avons pu définir, pour un support mis en forme par calandrage et un support mis en forme par enduction, les paramètres majeurs agissant sur la qualité d'impression. En termes de procédé, il apparaît que la vitesse d'impression et la pression du cylindre presseur influencent grandement l'imprimabilité. Au niveau des matériaux utilisés, la viscosité et la tension de surface de l'encre ont un effet important alors qu'en termes de support, un film calandré sera plus sensible aux variations des différents paramètres qu'un film enduit. / Printing quality idea is hard to control. In industry, eye is often used to judge the quality of a printed polymer film. In order to get a new level in terms of printing quality and get “point by point” or “all-over” quality, it is necessary to find a way to quantify printing quality. Some elements are important concerning the quantification of the printing quality: an optical microscopic image, a value of the average intensity and a value on the homogeneity of the color. We can define, for a calendered and a coated substrate, the main parameters acting on the printing quality. Printing speed and pressure of the rubber roll are the two main process parameters to act, viscosity and surface tension of the ink are the two main ink properties to act, while the calendered substrate is more sensitive to the variation of the parameters than the coated one.

Diversos pesquisadores vêm investigando métodos e técnicas para tornar possível às pessoas anotarem vídeos de modo transparente. A anotação pode ser realizada com a fala, com o uso de tinta digital ou algum outro meio que possa ser capturado enquanto a pessoa assiste ao vídeo. Tais anotações podem ser compartilhadas com outras pessoas, que podem estar assistindo ao mesmo vídeo em um mesmo instante ou em momentos diferentes, sendo interessante ainda que as anotações possam ser realizadas por várias pessoas de modo colaborativo. O paradigma Watch-and-Comment (WaC) propõe a captura transparente de anotações multimodais de usuários enquanto os mesmos assistem e comentam um vídeo. Como resultado desse processo, é gerado um vídeo digital interativo integrando o conteúdo original às anotações realizadas. Esta dissertação tem por objetivo explorar conceitos de computação ubíqua, redes sociais, redes peer-to-peer e TV interativa na proposta de um modelo arquitetural de ciência de informações de contexto para aplicações definidas segundo o paradigma WaC. O modelo explora a integração de um serviço ao paradigma, que auxilie ou forneça alternativas para que aplicações, do momento da captura ao acesso das anotações, utilizem informações de contexto do usuário, do vídeo e das anotações. O modelo também auxilia no estudo de colaboração entre usuários que realizam anotações em vídeos. Outra contribuição da dissertação é a prototipação de aplicações para avaliar e refinar o modelo proposto. São apresentadas extensões para a aplicação WaCTool, considerando o uso de redes sociais e de alternativas para a anotação em vídeos / Researchers have been investigating methods and techniques to allow people to annotate videos ubiquitously. Annotations can be made using voice, digital ink or some other media that can be captured while a person watches a video. These annotations can be shared with other people, who can be watching a video on the same time or at a different one. Also, these annotations can be made by many people collaboratively. The Watch-and-Comment (WaC) paradigm aims at capturing multimodal annotations in an ubiquitous way, while users watch and comment some video. As a result, an interactive digital video is generated combining the original content and the annotations. The work reported on this thesis explores concepts such as ubiquitous computing, social networks, peer-to-peer networks and interactive digital TV, to propose an architectural context-aware model to the applications defined by WaC paradigm. The model proposes the integration of a new service to the paradigm, supporting applications on the annotation process by offering capture alternatives and using context information from user, video and annotations. Also, the model provides a study in collaborative annotation process. Another contribution of this thesis is the prototypes built to evaluate and upgrade the proposed model. The prototypes are extensions from WaCTool, considering the use of social networks and alternatives to annotate in videos

No description available.

L’électronique souple utilisée dans les technologies RFID et NFC est aujourd’hui en plein essor et la demande croît exponentiellement chaque année. De nombreuses applications sont possibles comme les antennes RFID et les conducteurs transparents. Pour répondre à cette demande, il est nécessaire de proposer une technologie de fabrication à bas coût. Aujourd’hui les antennes sont fabriquées en R2R (Roll to Roll) par des méthodes soustractives à des coûts trop élevé et générant des déchets. Les méthodes d’impressions, qui sont additives, permettent aujourd’hui de réaliser des objets à la demande. L’objectif de cette thèse est de développer une technologie de rupture par rapport à l'existant. Les développements actuels se faisant majoritairement sur des nanoparticules d’argent, la stratégie de la thèse a été de développer un primaire métallisable (encre catalytique) pour la métallisation par voie chimique (electroless Cuivre). Dans cette étude nous avons abordés les différentes étapes qui ont permis de sélectionner le polymère adéquat pour la métallisation par voie chimique, à basse température, d'optimiser son greffage ainsi que son incorporation dans une formulation complète d’encre catalytique. Différentes preuves de concepts ont été obtenues grâce à la technologie développée par voie jet d’encre. La métallisation electroless permet d’obtenir une résistivité de 1.8 µΩ.cm et une excellente adhésion sur des substrats souples peu onéreux de faible point de transition vitreuse comme le PET et le PVC. La température du procédé de métallisation n’excède pas 50 °C. / The flexible electronics used in RFID and RFID and NFC technologies is now a booming market and demand is growing exponentially each year. Many applications are possible, such as RFID antennas and transparent conductors. To meet this demand, it is necessary to offer a low-cost manufacturing technology. Today antennas are manufactured in R2R (Roll to Roll) by subtractive methods and at high cost and generating waste. The methods of printing, which are additive, allow today to realize objects on demand. The aim of this thesis is to develop a breakthrough technology compared to the existing one. The current developments are predominantly done thanks to silver nanoparticles, the strategy of thethesis was to develop a metallizable primer (catalytic ink) for metallization by chemical means (electroless copper). In this study we will see the different steps that allowed us to select the appropriate polymer for chemical metallization, at low temperature and optimize its grafting as well as its incorporation in a complete formulation of catalytic ink. Different proofs of concepts have been obtained thanks to the technology developed by inkjet. The metallization electroless makes it possible to obtain a resistivity of 1.8 μΩ.cm and a very good adhesion on the inexpensive flexible substrates and weak point of glass transition polymer such as PET and PVC. The temperature of the metallization process does not exceed 50 °C.

<div> <div> <div> <p>Transparent alumina is a candidate material for ballistic applications where visible or infrared wavelength transmission is required. However, the transparency of polycrystalline alumina can be limited due to the rhombohedral crystal structure being inherently birefringent. Birefringence causes light scattering at grain boundaries and is detrimental to the transparency. It has been shown experimentally that the application of a high magnetic field during processing can lead to crystallographic alignment and the reduction of birefringent light scattering. This alignment method is effective but is limited in terms of scalability. This research addresses these limitations through the use of simple and cost-effective shear and elongational forming processes such as uniaxial warm pressing and direct ink writing (DIW) for the improvement of final sintered transparency. To further support the improvement of these processes as alternatives and to evaluate the possibility of using powder ratios to improve the alignment, this research will also investigate the sintering behavior during hot-pressing of equiaxed and platelet powders. </p> <p>Platelet ceramic-filled thermoplastic blends were developed and formed into sheets through uniaxial warm pressing. The solids loading (30 – 40 vol.%) and platelet diameter (1.2 and 11μm) were varied to compare effects on viscosity, percent reduction, and final alignment. All ceramic- filled thermoplastic polymer blends exhibited pseudoplastic behavior. Crystallographic alignment of green body samples was quantified by the orientation parameter (r) and grain misalignment angle (full width at half maximum, FWHM) obtained from rocking curve analysis. Blends with 11μm diameter platelets displayed a higher temperature sensitivity constant, better flow properties, and higher alignment compared to blends with 1.2μm diameter platelets. Optimal samples produced with blends containing 30 vol.% of 11μm diameter platelets demonstrated an alignment of r = 0.251 +/- 0.017; FWHM = 11.16° +/- 1.16°. A sample with optimal alignment was hot-pressed to transparency and obtained an in-line transmission of 70.0% at 645nm. The final alignment of this pre-aligned hot-pressed sample (r = 0.254 +/- 0.008; FWHM = 11.38° +/- 0.54°) improved when compared to a non-pre-aligned sample (r = 0.283 +/- 0.005; FWHM = 13.40° +/- 0.38°).</p><p>Additionally, the use of direct ink writing, an additive manufacturing technique, as a viable alignment process for producing transparent alumina was investigated. Highly loaded (> 54 vol.%) equiaxed alumina suspensions were developed with platelet additions ranging from 0-20vol.% of the total solids loading. An increase in the amount of platelet powders from 5-20vol.% increased the dynamic yield stress from 104Pa to 169Pa and decreased in the equilibrium storage modulus from 17,036Pa to 13,816Pa. It was found that the DIW process significantly increased the alignment in one orientation when compared to samples cast from the same suspensions and this behavior may be connected to the rheological properties. Lastly, an optical analysis showed that sample developed with 5vol.% platelet suspensions had higher in-line transmission values across the visible spectrum when compared to samples developed with 20vol.% suspensions. A sample cast from a 5vol.% platelet suspensions had the lowest grain alignment but possessed an in-line transmission of 42.8% at 645nm, which was the highest of the samples produced in this study. An optical loss analysis showed, that this sample has the lowest backwards scattering losses due to residual porosity and this result was supported by the density data. It is suggested that the alignment of the DIW samples is more complex and a more advanced texture analysis will need to be conducted to properly characterize the grain alignment.</p><p>Lastly, the densification behavior of equiaxed and platelet powder ratios with no intentional pre-alignment was investigated. An initial sintering investigation identified the optimum maximum pressure selected for the hot-pressing process as 20MPa. Under the selected hot- pressing parameters, the effects of 0, 25, 50, 75, and 100wt.% equiaxed powder additions on the sintering behavior, optical properties, and grain alignment was investigated. The data showed that an increase in the amount of equiaxed powders decreased the initial powder compact displacements rate. Additionally, an increase in the wt.% equiaxed powders from 0wt% to 75wt% decreases the in-line transmission from 70.9% to 40.2%, respectively at 645nm. Lastly, an increase in the wt.% equiaxed powders from 0wt% to 75wt decreased the alignment from (r = 0.321 +/- 0.005; FWHM = 16.26° +/- 0.40°) to (r = 0.509 +/- 0.022; FWHM = 34.63° +/- 2.61°), respectively.</p></div></div></div>

(in English): This thesis is conceived as a metareview of research on differences in perception, understanding and retention of text on various display media. It summarizes the results of the most interesting and most relevant research on this topic conducted since the 80s to the present. Even though it is difficult to summarize the results of individual studies, mainly because of differences in research methodology and differently chosen tested samples, we can say that the main finding of this metareview is that display technologies that are available these days have no negative effect on eye fatigue, reading speed, perception, understanding or retention of text. Theoretical part of this thesis is followed by practical part that consists of three short experiments performed on a small sample of participants. First of those experiments studies differences in reading comprehension and retention among high school students, second experiment focuses on differences in reading speed on different media and subjective evaluation of eye fatigue, and the third experiment is an online form about subjective preferences of study materials among learners.

Microsieves are permeable membranes with excellent properties for filtration applications. In this thesis the inkjet-technology is applied (1) to manufacture micro-porous microsieves, and (2) to reinforce the mechanical stability of float-cast, nano-porous microsieves: (1) The current process for inkjet-printed microsieves includes a manual step which is substituted by inkjet printing in order to increase the level of automation. The obtained microsieves are characterized regarding the pore size distribution. Effects which occur during the manufacture and broaden the pore size distribution are identified. Based on the results, the process is improved to obtain fully inkjet-printed microsieves with a narrowed pore size distribution. (2) The mechanical stability of fragile, float-cast microsieves is improved by the application of inkjet-printed reinforcement patterns on top of the microsieves. A machine is built to combine both technologies of float-casting and inkjet printing. The printing process is improved to manufacture reinforcement patterns of well-defined geometry. / Mikrosiebe sind permeable Membranen mit herausragenden Eigenschaften für die Anwendung in der Filtration. In der vorliegenden Dissertation wird die Inkjet-Drucktechnologie angewandt, um (1) mikroporöse Mikrosiebe herzustellen und (2) nanoporöse Mikrosiebe mechanisch zu stabilisieren: (1) Die Herstellung von Mikrosieben mittels Inkjet-Druck beinhaltet momentan einen manuellen Schritt, der durch einen Inkjet-Druckschritt ersetzt wird, um den Automatisierungsgrad des Verfahrens zu erhöhen. Die Mikrosiebe werden bezüglich der Porengrößenverteilung untersucht. Auftretende Effekte, die die Porengrößenverteilung verbreitern, werden identifiziert. Aus den Resultaten dieser Analyse wird der Prozess optimiert, um Mikrosiebe mit einer engen Porengrößenverteilung herzustellen. (2) Die mechanische Stabilität von fragilen Mikrosieben, die mittels Float-Casting hergestellt werden, wird durch das Aufbringen einer Stützstruktur mittels Inkjet-Druck verstärkt. Ein Maschinensetup wird aufgebaut um beide Technologien des Float-Castings und des Inkjet-Drucks zu kombinieren. Weiterhin wird der Prozess dahingehend optimiert, Stützstrukturen mit wohl-definierten Parametern zu erzielen.

In this work, the use of a lunar regolith simulant as feedstock for the direct ink writing additive manufacturing process is explored, the purpose of which is to enable future lunar in-situ resource utilisation. The feasibility of this approach is demonstrated in a laboratory setting by manufacturing objects with different geometries using methyl cellulose or sodium alginate as binding agents and water as liquid phase together with the lunar regolith simulant EAC-1A to create a viscous, printable ‘ink’ that is used in combination with a custom three-axis gantry system to produce green bodies for subsequent sintering. The sintered objects are characterised using compressive strength measurements and scanning electron microscopy (SEM). It is proposed that the bioorganic compounds used in this work as additives could be produced at the site for a future lunar base through photosynthesis, utilising carbon dioxide exhaled by astronauts together with the available sunlight, meaning that all the components used for the dispersion – additive, water (in the form of ice) and regolith – are available in-situ. The compressive strength for sintered samples produced with this method was measured to be 2.4 MPa with a standard deviation of 0.2 MPa (n = 4). It is believed, based on the high sample porosity observed during SEM analysis, that the comparatively low mechanical strength of the manufactured samples is due to a non-optimal sintering procedure carried out at a too-low temperature, and that the mechanical strength could be increased by optimising the sintering process further.

No description available.