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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of a GXL-GRAIL Serializer/Deserializer

Lindemann, Markus January 2008 (has links)
<p>GRAIL is a Java library for capturing and manipulating graphs. It is used in the VizzAnalyzer reengineering tool developed at Växjö University that allows quality analysis of software systems.</p><p>GXL is a standard exchange format for software data in graph structure, mainly used within the field of software reengineering that is widely supported in other tools within the same field. It is important for VizzAnalyzer to support GXL as an exchange format to allow collaboration with other tools on this basis.</p><p>As the goal of this thesis, a GXL graph serializer/deserialize architecture for GRAIL has been developed that allows data exchange between VizzAnalyzer and other tools that support the GXL format.</p><p>VizzAnalyzer is capable of analyzing large software systems and therefore the task required special attention on high performance and low memory footprint even with large GXL graph structures.</p>
2

Development of a GXL-GRAIL Serializer/Deserializer

Lindemann, Markus January 2008 (has links)
GRAIL is a Java library for capturing and manipulating graphs. It is used in the VizzAnalyzer reengineering tool developed at Växjö University that allows quality analysis of software systems. GXL is a standard exchange format for software data in graph structure, mainly used within the field of software reengineering that is widely supported in other tools within the same field. It is important for VizzAnalyzer to support GXL as an exchange format to allow collaboration with other tools on this basis. As the goal of this thesis, a GXL graph serializer/deserialize architecture for GRAIL has been developed that allows data exchange between VizzAnalyzer and other tools that support the GXL format. VizzAnalyzer is capable of analyzing large software systems and therefore the task required special attention on high performance and low memory footprint even with large GXL graph structures.
3

Role of carbon dioxide in gas expanded liquids for removal of photoresist and etch residue

Song, Ingu 08 October 2007 (has links)
Progress in the microelectronics industry is driven by smaller and faster transistors. As feature sizes in integrated circuits become smaller and liquid chemical waste becomes an even greater environmental concern, gas expanded liquids (GXLs) may provide a possible solution to future device fabrication limitations relative to the use of liquids. The properties of GXLs such as surface tension can be tuned by the inclusion of high pressure gases; thereby, the reduced surface tension will allow penetration of cleaning solutions into small features on the nanometer scale. In addition, the inclusion of the gas decreases the amount of liquid necessary for the photoresist and etch residue removal processes. This thesis explores the role of CO2-based GXLs for photoresist and etch residue removal. The gas used for expansion is CO2 while the liquid used is methanol. The cosolvent serving as the removal agent is tetramethyl ammonium hydroxide (TMAH) which upon reacting with CO2 becomes predominantly tetramethyl ammonium bicarbonate (TMAB).
4

Switchable Solvents for Novel Chemical Processing

Grilly, Joshua David 15 August 2005 (has links)
This work seeks to develop new solvents for environmentally benign chemical synthesis. Switchable solvents are a new class of compounds that change properties upon the application of some stimulus such as heat, UV light, or pH. We have developed the use of a new solvent, thiirane oxide, that has chemical properties similar to DMSO. Thiirane oxide, however, undergoes facile decomposition to two gases at temperatures above 100 C, which is much lower than the temperature required for removing DMSO. Thus we have a solvent with excellent solvation properties, but with a built-in switch for easier removal. However, thiirane oxide leaves behind sulfurous products which make the reverse reaction to reform the solvent unfeasible. We are also developing the use of another solvent, piperylene sulfone, which is expected to have good solvent properties, yet with decomposition products that can be reacted to reform the solvent. This thesis also details the work to date on piperylene sulfone. Gas-expanded liquids (GXLs) also show promise as a new reaction medium. In order to design solvent systems that take full advantage of this medium, we desire to understand the microstructure of these fluids. To that end, we are using cage reactions to probe solute-solvent and solvent-solvent interactions at the molecular level. This thesis discusses the current research on using cage reactions to probe the structure of GXLs.
5

Fluides supercritiques et solvants biosourcés : propriétés physicochimiques des systèmes expansés par du CO2 / Supercritical fluids and biosourced solvents : physicochemical properties of CO2-expanded systems

Granero-Fernandez, Emanuel 19 October 2018 (has links)
Les objectifs environnementaux (COP21) visant à réduire les émissions de gaz à effet de serre et l'impact de l'industrie sur la nature, font face au défi de la demande croissante d'énergie et de produits. Les procédés chimiques sont les premiers en cause lorsqu’ils mettent en œuvre des solvants. L'ingénierie des solvants est une solution innovante qui vise à trouver des milieux alternatifs bénins possédant les propriétés de solvant adaptés pour chaque étape du procédé.Dans cette perspective, nous avons étudié les Liquides expansés par un gaz (LEGs), qui sont desliquides dont le volume augmente sous l’effet d’un gaz dissous sous pression. En particulier, le CO2 peut être utilisé comme agent d'expansion pour obtenir des liquides expansés par du CO2(LECs), combinant les avantages du CO2 et du solvant. La phase expansée peut contenir des concentrations élevées de CO2, jusqu'à 80%, selon le solvant, ce qui conduit à une réduction du besoin du solvant organique, mais aussi à des changements des propriétés physicochimiques et de transport de la nouvelle phase expansée. On peut de plus moduler ces propriétés par la pression et la température, d'une manière réversible, et améliorer la séparation des produits. Dans cette étude, différents solvants biosourcés ont été utilisés pour obtenir des systèmes expansés par du CO2, tels que les acétates d'alkyle, les carbonates organiques, les méthoxybenzènes, etc.La connaissance des équilibres de phase, des propriétés de solvatation et de transport est essentielle pour concevoir des processus qui exploitent le comportement particulier de ces systèmes biphasiques. Deux approches principales ont été utilisées pour caractériser ces systèmes. Dans un premier temps, des mesures ont été effectuées dans une cellule à haute pression et à volume variable pour évaluer la polarité au travers du paramètre Kamlet-Taft (KT) *(dipolarité / polarisabilité) dans les solvants expansés par du CO2 sous des pressions allant jusqu'à 30 MPa. La technique utilisée a été la spectroscopie UV-Vis suivant le déplacement hypsochromique du Rouge de Nile, une sonde solvatochromique déjà utilisée pour obtenir les paramètres KT dans des solvants purs. De plus, des mesures d'équilibre vapeur-liquide (ELV) ont été effectuées pour obtenir la composition de la phase expansée à différentes pressions et températures afin de comprendre la solvatation du CO2 dans les solvants organiques et de fournir des informations manquantes dans la littérature. En deuxième lieu, dans une approche plus théorique, les données ELV ont été utilisées pour calculer numériquement d'autres propriétés telles que la densité et la viscosité. Des équations d'état et des simulations par dynamique moléculaire (DM) ont été utilisées ; ces dernières donnant de meilleurs résultats dans un mode prédictif de la masse volumique et permettant de suivre les positions moléculaires au cours du temps, qui peut être liée à de nombreuses propriétés, y compris la viscosité étudiée ici. Ces calculs ont été effectués en utilisant un champ de force de type Amber adapté. Les résultats obtenus dans l’ensemble complètent les données de la littérature existante et apportent de nouvelles informations sur les propriétés des LEGs. Par exemple, le comportement non linéaire de l'expansion volumétrique, vérifié après les déterminations de masse volumique sur les simulations DM à l'équilibre, est une clé dans la compréhension des interactions soluté-solvant ; ainsi que les valeurs KT * obtenues qui confirment la large gamme de polarité couverte par ces systèmes.Enfin, certains systèmes expansés par du CO2 ont été utilisés pour produire des nanoparticules de TiO2 pour panneaux solaires, améliorant leur surface spécifique et donc leur efficacité en tant que semi-conducteurs ; et d’autres ont été appliqués à un processus d'activation enzymatique entraînant une augmentation significative du taux de conversion / Over the last two decades, environmental goals (COP21) aiming to reduce Greenhouse Gasemissions and industry impact on nature, face the challenge of the increasing demand for energyand products. Chemical processes are in the center of the scene because of the use of solvents.Solvent engineering is the strategy to find alternative benign media for different applications, oreven to adapt solvent properties to respond each stage of a process, and represents aninteresting alternative to propose innovative solutions to industrial problems. With this perspective,Gas-expanded Liquids (GXLs), which are liquids whose volume is expanded by a pressurizeddissolved gas, represent a very promising tool yet to be implemented in the industry. CO2 can beused as the expansion agent to obtain CO2-expanded Liquids (CXLs), combining both the CO2and the solvent’s advantages. The expanded phase can contain high concentrations of CO2 (up to80%, depending on the solvent), which can lead not only to an effective reduction of the need foran organic solvent, but also to changes in the physicochemical and transport properties of the newexpanded phase, that can now be tuned by pressure and temperature in a reversible fashion, andimprove product separation. In this study, different bio-sourced solvents have been used to obtainCO2-expanded systems, such as alkyl acetates, organic carbonates, methoxybenzenes, etc.Knowledge of phase equilibria, solvation and transport properties are fundamental to designprocesses that exploit the peculiar behavior of these two-phase systems. Two main approacheshave been used to characterize these systems. At first, physical determinations were carried outin a high pressure, variable volume view cell, to measure polarity through Kamlet-Taft (KT) *parameter (dipolarity/polarizability) in the selected CO2-expanded solvents under pressures up to30 MPa. The technique used was UV-Vis spectroscopy following the hypsochromic shift of NileRed, a solvatochromic probe that has already been used to obtain KT parameters in neat solvents.Also, Vapour-Liquid Equilibria (VLE) measurements were performed to obtain the expanded phasecomposition at different pressures and temperatures as an attempt to understand CO2 solvation inorganic solvents and to provide missing information in literature. In second place, in a moretheoretical approach, VLE data was used to numerically calculate other properties such as densityand viscosity. Both Equations of State (EoS) and Molecular Dynamics (MD) simulations wereused, giving this last technique better results in a pure predictive mode like in the case of densitydeterminations; in addition to the ability to trace molecular positions over time, which can berelated to many properties, including the here studied viscosity. These calculations were carriedout using an Extended AMBER potential, which led to fairly good results compared to specific-usepotentials available in literature, with the advantage of the general-use possibility. From all thesedeterminations, different conclusions were drawn both agreeing with existing and providing newdata to the literature surrounding this promising subject. For instance, the generally non-linearbehavior of volumetric expansion, verified after density determinations on equilibrium MDsimulations, that is key to evaluate solute-solvent interactions; as well as the KT * values obtainedthat confirm the large range of polarity covered by these systems. Finally, some CO2-expandedsystems were used to produce TiO2 nanoparticles for solar panels improving their specific surfaceand therefore their efficiency as semiconductors; and some others applied to an enzyme activationprocess leading to significant enhancement in conversion rate

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