The present study estimated the Energy Conservation Potential (PCE) of the lighting and air conditioning systems of the Federal Institute of Sergipe (IFS) – Campus Lagarto. Both systems were classified according to the Technical Regulation of Quality for the Energy Efficiency Level of Commercial Buildings, Services and Public Buildings (RTQ-C), Inmetro Ordinance n.º 372, of September 17, 2010. The analysis was done using the comparative method to check the installed power and how much could be saved if efficient air conditioning units and lamps were used instead of the current ineffective ones. With regard to the lighting system, it was verified that the institution has 66.576 kW of installed load. The efficiency of this system was analyzed by the method of the building activities included in the RTQ-C and the initial hypothesis that the system was inefficient was verified. There was a great amount of burned lamps and that many environments did not have switches to control the lighting circuit in the place where the activities are carried out, besides the lack of natural light and the nonautomation of the places with areas bigger than 240 m2. This made, after checking the requirements, the building receives the C classification. It was simulated the replacement of the fluorescent lamps by LED and found a significant energy conservation potential of 39.90% and it was found enough to completely illuminate the whole building spending only 1.01% more energy than is currently spent with the working lamps. Regarding the air conditioning system, the building has a total of 2.5665 million of BTU/h (752.166 kW or 213.875 TR), implying 271.048 kW of installed power connected to the electric grid. All airconditioned environments in the FIS - Campus Lagarto were evaluated and 91 units were found, distributed in three types: window, split floor -ceiling and split Hi-wall. Of this total, 73 equipment’s are of classification level D, being this also the general conjuncture of the system. When calculating the energy conservation potential, it reached 29.30%, and in some equipment, simple replacement can generate savings of 53.06%. Regarding the emissions from the acquisition of electric energy in the period from 2010 to 2015, the FIS - Campus Lagarto registered the consumption of 1.38 MWh of electricity, incurring 142.181 tCO2 of emissions. It was identified 106 trees planted in the institution, being the minimum quantitative recommended for the neutralization of these of 1655 trees. If FIS - Campus Lagarto wanted to use the carbon credits market to do so, it would have to pay the sum of R$ 2872.44. It is therefore recommended that the institution conduct a complete inventory of its GHG emissions and plant a forest or forest reserve outside the Campus to neutralize its emissions and use it for research and/or scientific studies. It is also suggested to the school that creates a permanent Environmental Education Project aimed at reducing waste in the consumption of electric energy and adoption of environmentally sustainable practices. / A presente pesquisa estimou o Potencial de Conservação de Energia (PCE) dos sistemas de iluminação e condicionamento de ar do Instituto Federal de Sergipe (IFS) – Campus Lagarto. Ambos foram classificados de acordo com o Regulamento Técnico da Qualidade para o Nível de Eficiência Energética de Edifícios Comerciais, de Serviços e Públicos (RTQ-C), Portaria Inmetro n.º 372, de 17 de setembro de 2010. A análise foi feita utilizando-se o método comparativo para verificar a potência instalada e o quanto poderia ser economizado se fossem utilizadas unidades condicionadoras de ar e lâmpadas eficientes no lugar das atuais ineficazes. No que diz respeito ao sistema de iluminação, constatou-se que a instituição possui 66,576 kW de carga instalada. Analisou-se a sua eficiência pelo método das atividades do edifício constantes no RTQ-C e comprovou-se a hipótese inicial de que o mesmo está ineficiente. Verificou-se uma grande quantidade de lâmpadas queimadas e que muitos ambientes não possuíam interruptores para comandar o circuito de iluminação no local onde são realizadas as atividades, além do não aproveitamento da iluminação natural e da não automatização dos locais com áreas maiores que 240 m2. Isto fez, após a verificação dos requisitos, a edificação receber a classificação C. Foi simulada a substituição das lâmpadas fluorescentes por LED e encontrou-se um significativo potencial de conservação de energia de 39,90% e que se constatou suficiente para iluminar completamente todo o prédio gastando apenas 1,01% mais energia do que atualmente é despendido com as lâmpadas operantes. Quanto ao sistema de condicionamento de ar a edificação possui um total de 2,5665 milhões de BTU/h (752,166 kW ou 213,875 TR), implicando em 271,048 kW de potência instalada conectada à rede elétrica. Foram avaliados todos os ambientes climatizados no IFS - Campus Lagarto e encontradas 91 unidades, distribuídas em três tipos: janela, split piso-teto e split Hi-wall. Desse total, 73 equipamentos são de nível de classificação D, sendo esta também a conjuntura geral do sistema. Ao se calcular o potencial de conservação de energia, chegou-se ao número de 29,30%, sendo que, em alguns equipamentos, a simples substituição pode gerar economia de 53,06%. Já em relação às emissões oriundas da aquisição de energia elétrica no período de 2010 a 2015, o IFS – Campus Lagarto registrou o consumo de 1,38 MWh de energia elétrica no intervalo de tempo considerado, incorrendo em 142,181 tCO2 de emissões. Foram identificadas 106 árvores plantadas na instituição, sendo o quantitativo mínimo recomendável para a neutralização destas de 1.655 árvores. Caso o IFS – Campus Lagarto desejasse utilizar o mercado de créditos de carbono para tal, despenderia a quantia de R$ 2.872,44. Recomendase, portanto, que a instituição realize um inventário completo das suas emissões de GEEs e plante um bosque ou uma reserva florestal fora do Campus a fim de neutralizar as suas emissões e utilizá-lo em pesquisas e/ou estudos científicos. Também é sugerido ao estabelecimento de ensino que crie um Projeto de Educação Ambiental local e permanente visando à redução do desperdício no consumo de energia elétrica e adoção de práticas ambientalmente sustentáveis.

Les travaux présentés dans cette thèse peuvent être divisés en deux parties. Dans une première partie, nous avons étudié le processus de photoisomérisation dans plusieurs systèmes. Une analyse de structure électronique accompagnée d’un calcul préliminaire de dynamique semi-classique ont été appliqué à un modèle minimal du rétinal afin d’extraire les degrés de libertés les plus importants lors de l’isomérisation. Cela dans le but de construire des surfaces d’énergie potentielle diabatiques pour effectuer une étude de dynamique quantique. Une approche de type dynamique semi-classique a été appliquée à un modèle de moteur moléculaire dans le but d’étudier l’origine de l’uni-directionalité de sa rotation. Finalement, une étude de structure électronique d’un complexe de Rhénium contenant un ligand de type rétinal a été effectué pour étudier l’influence du métal sur la spectroscopie du ligand rétinal. Dans une deuxième partie nous nous sommes intéressés à l’étude des croisements intersystème dans un complexe de Rhénium. Afin de pouvoir apporter une explication à un comportement contrintuitif de ce complexe, nous avons développé un Hamiltonien modèle capable de tenir compte des couplages vibroniques interétats et spin-orbit. Cet Hamiltonien a été testé sur ce-dit système, et nous a permis, grâce à une étude de structure électronique de proposer un mécanisme de relaxation différent de celui proposé expérimentalement. / This thesis can be divided in two parts.In the first one, we have studied the photoisomerization process in several systems. An electronic structure analysis mixed with a preliminary semi-classical dynamics investigation has been applied to a minimal model of the retinal chromophore in order to select the most important degrees of freedom involved in the process. The goal of this is to build diabatic potential energy surfaces in order to conduct quantum dynamics simulations. A semi-classical approach has also been applied to a molecular motor model to study the origin of the unidirectionality of its rotary motion. Finally, an electronic structure of a rhenium complex with a retinal-like ligand has been performed to study the effect of the coordination to a metallic atom on the spectroscopy of the retinal ligand. In the second part, we have investigated the intersystem crossings in a rhenium complex. In order to bring an explanation to an experimentally observed conterintuitive behavior of this complex, we have developed a model Hamiltonian that includes both interstate vibronic coupling and spin-orbit coupling. This Hamiltonian has been tested on the said complex and, in complement to an electronic structure study, allowed us to formulate a decay mechanism different from the one proposed based on experiments.

Comprendre l’origine microscopique du ralentissement de la dynamique au voisinage de la transition vitreuse reste l’un des problèmes fondamentaux de la physique de la matière condensée. Au cours de ce travail, nous introduisons un nouveau modèle de liquide, appelé liquide de Voronoï, et dont les interactions sont directement reliées aux propriétés géométriques des tessellations de Voronoï. Pour cette classe de liquides, les interactions sont à plusieurs corps et agissent de telle sorte que le système est toujours sous tension tout en restant stable. Le but de ce travail est d’étudier un mélange binaire du liquide de Voronoï et de voir de quelles façons ces interactions exotiques affectent le scénario habituel de la transition vitreuse. Tout au long de ce travail, nous caractérisons le liquide de Voronoï bidisperse théoriquement et par le biais des simulations numériques. Nous proposons également des comparaisons avec des liquides de Lennard-Jones surfondus bien décrit dans la littérature. / Understanding the origin of the important slowing down of the dynamics near glass transition is still one of the remaining fundamental problems of condensed matter physics. During this work we introduced a brand-new model of liquids named Voronoi liquid, whose interactions are directly related to the geometrical properties of Voronoi tessellations. For these class of liquids interactions are intrinsically manybody and act in such a way that the liquid is always under tension but remains stable. The aim of this work is to use a binary mixture of the Voronoi liquid to see to what extend these exotic interactions may affect the classical scenario of glass transition. Throughout this work we characterize theoretically and by mean of numerical simulation the bidisperse Voronoi liquid. Comparisons with well-known Lennard-Jones glass formers are systematically performed.

This work aims at calculating the cross sections for vibrational excitation of the oxygen molecules by collisons with electrons. Potential energy curves are obtained with standard quantum chemistry methods and the R-matrix method with good agreement with measurable molecular properties, the cross sections are calculated within the local complex potential approximation. It was shown that the results obtained with different, but seemingly satisfactory settings can vary by a significant degree. Comparison with experimental data then point out the insufficiency of the local complex potential approximation. Powered by TCPDF (www.tcpdf.org)

Les travaux de cette thèse ont porté sur le développement de deux méthodes de modélisation des enzymes contenant des groupes prosthétiques de la famille des flavines.La première méthode, PredFace, permet de prédire la stéréochimie des produits d'une réaction catalysée par des enzymes contenant des groupes prosthétiques, en identifiant la face libre d'interaction avec les substrats. Le protocole mis en place pour cette méthode implique l'utilisation de huit complexes "sondes", obtenus par des opérations de symétrie à partir de l'état de transition de la réaction de transfert d'un atome d'hydrogène entre le nicotinamide et la lumiflavine. Ces complexes sont positionnés dans le site actif avec le groupe prosthétique comme référence et dans chaque cas l'énergie d'interaction protéine-ligand est évaluée par la fonction de score implémentée dans le logiciel de docking utilisé (AutoDock). L'énergie d'interaction la plus favorable permet d'identifier la face du groupe prosthétique accessible pour la réaction enzymatique dans le site actif. La méthode PredFace a été validée par l'analyse de l'ensemble des structures de la Protein Data Bank contenant des groupes prosthétiques de la famille des flavines (2170). Le protocole mis au point est très rapide (moins d'une minute), ce qui nous a permis de développer un site web afin de mettre cette méthode à la disposition de la communauté.La seconde méthode, ProsthDock, est une nouvelle méthode de docking basée sur le mécanisme d'une réaction enzymatique catalysée par un groupe prosthétique et guidée par la présence de ce groupe prosthétique dans le site actif de l'enzyme. Le développement de cette méthode a été motivé par le fait que les méthodes actuelles de docking, en présence de groupes prosthétiques, se révèlent incapables de produire des poses correctes pour des substrats, en accord avec les réactions enzymatiques. Afin de remédier à ce problème nous avons ajouté à la fonction de score classique un terme supplémentaire, qui rendra compte de l'interaction du ligand avec le groupe prosthétique. Dans un premier temps, nous avons construit un modèle simplifié du complexe NADH/FMN et calculé l'état de transition de la réaction de transfert d'hydrogène entre les deux partenaires. Des surfaces d'énergie potentielle pour cette réaction ont été calculées en variant la distance, l'angle et l'angle dièdre entre les deux réactifs. Un docking sous contrainte est ensuite réalisé et en fonction du positionnement de chaque pose de docking dans le site actif le terme supplémentaire de la fonction de score est calculé à partir des surfaces d'énergie potentielle, ce qui nous permet de modifier le classement des résultats de docking en favorisant les poses qui sont en accord avec la réaction enzymatique. / During this PhD thesis we developped two new molecular modeling methods applied to enzymes containing flavin-type prosthetic groups.The first method, PredFace, predicts the stereochemistry of products from a reaction catalyzed by enzymes containing prosthetic groups, by automatically identifying the solvent-exposed face of the prosthetic group. The protocol involves the use of eigth complexes as "probes", obtained by symmetry operations starting from the transition state of a hydrogen atom transfer reaction between nicotinamide and lumiflavin. These complexes are positioned in the binding site with the prosthetic group as reference and the energy of the protein-ligand interaction is evaluated by the scoring function implemented in the docking software (AutoDock). The most favorable interaction energy allows the identification of the prosthetic group face that is available for the enzymatic reaction in the binding site. The PredFace method has been validated by analyzing all the structures in the Protein Data Bank containing flavin-derived prosthetic groups (2170). This method is very fast (less than a minute), which allowed us to develop a web site open to the scientific community.The second method, ProsthDock, is a new mechanism-based molecular docking method guided by prosthetic groups present in the active sites of enzymes. The development of this method was motivated by the incapacity of the currently available docking methods to provide, in the presence of prosthetic groups, ligand conformations that are compatible with the enzymatic reactions. In this regard, we have added a new term to the classical scoring function, to take into account the interaction between ligand and prosthetic group. We have built a simplified model of the NADH/FMN complex and calculated the transition state of the hydrogen transfer reaction between the two partners. Potential energy surfaces have been calculated for this reaction by variating the angle, diedral angle and distance between the two reaction partners. A subsequent docking with constraints provides binding site conformations of the ligand for which the new term of the scoring function is calculated using the potential energy surfaces. This results in a new ranking of the docking poses, favoring those in agreement with the enzymatic reaction.

It is an aim of this work to provide insight into the energetic influence on the ordering of molecular thin films on crystalline substrates. Here, the term substrate either refers to inorganic crystal surfaces or highly ordered layers of another organic molecular species. In order to calculate the total interface potential of extended molecular domains, a new calculation technique (GRID technique) is developed in the first part of this work. Compared to the standard approach, this method accelerates the potential calculation drastically (times 10000). The other parts of the thesis are dedicated to the comparison of experimental results (obtained by scanning tunneling microscopy and electron diffraction) to the optimal layer structure as predicted by optimization calculations. Potential calculations which are performed for the system perylenetetracarboxylicdianhydride (PTCDA) on graphite demonstrate that point-on-line coincident structures correspond to energetically favorable alignments of the molecular lattice with respect to the substrate lattice. The capability of the GRID technique to predict the optimal layer structure is demonstrated for the system peri-hexabenzocoronene (HBC) on graphite. The organic-organic heteroepitaxy system PTCDA on HBC on graphite is investigated in order to clarify to which extent the ordering mechanism there differs from that of the organic-inorganic heteroepitaxy system PTCDA on graphite. As a result of this investigation, a new type of epitaxy, i.e., substrate induced ordering is found. This new epitaxy type is governed by the inner structure of the substrate lattice unit cell. Here, the substrate surface is a layer of organic molecules itself, hence the substrate surface unit cell does indeed exhibit a complex inner structure. A generalized classification scheme for epitaxial growth incorporating this new type of epitaxy is proposed. In the last chapter, the structure of the first layers of titanylphthalocyanine (TiOPc) on Au(111) is investigated and compared to potential optimization calculations. The correspondence of experimental and theoretical results provides evidence that the GRID technique can, in principle, also be applied to molecular layers on metal surfaces. / Das Ziel der vorliegenden Arbeit ist es, Einblicke in die energetischen Einflüsse, die zur Ausbildung der Schichtstruktur organischer Moleküle auf kristallinen Substraten führen, zu geben. Diese Substrate sind entweder Oberflächen anorganische Kristalle oder selbst hochgeordnete Molekülschichten. Um das totale Grenzflächenpotential ausgedehnter Moleküldomänen berechnen zu können, wird im ersten Teil der Arbeit eine neue Berechnungsmethode (GRID Technik) vorgestellt. Im Vergleich mit herkömmlichen Berechnungsmethoden auf der Basis molekülmechanischer Kraftfelder ist diese neue Methode daher um ein Vielfaches schneller (Faktor 100000). Die folgenden Teile der Arbeit sind dem Vergleich experimenteller Ergebnisse (Rastertunnelmikroskopie und Elektronenbeugung) mit, durch Potentialoptimierungsrechnungen als energetisch günstig vorhergesagten, Schichtstrukturen gewidmet. So kann für das System Perylentetracarbonsäuredianhydrid (PTCDA) auf Graphit mittels Potentialberechnungen nachgewiesen werden, daß die experimentell gefundenen ?Point-on-line koinzidenten? Strukturen energetisch günstige Anordnungen des Molekülgitters bezüglich des Substratgitters darstellen. Die Eignung der neuen Berechnungsmethode zur Vorhersage der günstigsten Adsorbatgitterstruktur für ein gegebenes System aus Molekül und Substrat, wird anhand des Systems peri-Hexabenzocoronen (HBC) auf Graphit demonstriert. Das organisch-organische Heteroepitaxiesystem PTCDA auf HBC auf Graphit wird untersucht, um zu klären, inwieweit sich die dafür gültigen Ordnungsmechanismen von denen unterscheiden, die für das Wachstum des organisch-anorganischen Heteroepitaxiesystems PTCDA auf Graphit verantwortlich sind. Dabei gelingt es, eine bisher nicht klassifizierte Art von Epitaxie, d.h. substratinduzierter Ordnung, nachzuweisen. Dieser neue Epitaxietyp ist bedingt durch die innere Struktur einer Substrateinheitszelle - das Substrat ist ja hier selbst eine Schicht geordneter Moleküle, die natürlich eine innere Struktur aufweisen. Im folgenden wird ein verallgemeinertes Klassifizierungssystem für Epitaxietypen abgeleitet, welches den neuen Epitaxietyp beinhaltet. Im letzten Kapitel wird die Struktur von der ersten Lagen von Titanylphthalocyanin (TiOPc) auf Au(111) experimentell untersucht und mit entsprechenden Potentialoptimierungsrechnungen verglichen. Die Übereinstimmung von experimentellen und theoretischen Ergebnissen zeigt, daß die GRID Technik, zumindest prinzipiell, auch für Molekülschichten auf Metallsubstraten anwendbar ist.

No description available.

Em geral, as formulações disponíveis na literatura para a análise de cascas laminadas reforçadas com fibras substituem o meio original heterogêneo por um homogêneo equivalente, que dificulta a identificação das tensões fibra-matriz, ou requerem que a malha de elementos finitos seja disposta de modo que os nós dos elementos finitos de fibra coincidam com os nós dos elementos finitos de casca, que é uma exigência bastante restritiva e que aumenta o número de graus de liberdade do sistema de equações resultante. Neste sentido, o objetivo geral desta tese consiste em desenvolver uma formulação para a inclusão de fibras longas e curtas aleatórias nas diversas lâminas de cascas laminadas anisotrópicas com não linearidade geométrica utilizando o método dos elementos finitos sem aumentar o número de graus de liberdade do sistema de equações resultante e sem a necessidade de coincidência de nós na discretização das fibras e da matriz. Nesta formulação, o elemento finito triangular de casca laminada utilizado para discretizar a matriz possui dez nós e sete graus de liberdade por nó, sendo três translações, três componentes do vetor generalizado e a taxa de variação linear da deformação ao longo da espessura. As fibras curvas, curtas aleatórias ou longas, são introduzidas, em qualquer camada do laminado, por meio de relações cinemáticas que garantem sua aderência à matriz sem a introdução de novos graus de liberdade no sistema de equações resultante. Para discretizá-las são utilizados elementos finitos unidimensionais de ordem qualquer com três graus de liberdade por nó e que consideram consistentemente a não linearidade geométrica. Todas as grandezas envolvidas são escritas em relação à configuração inicial do corpo, caracterizando a descrição Lagrangeana total ou material do movimento. Para modelar o comportamento do material adota-se a Lei Constitutiva de Saint-Venant-Kirchhoff que relaciona de forma linear o tensor de tensões de Piolla-Kirchhoff de segunda espécie e o tensor de deformações de Green-Lagrange. O equilíbrio é encontrado a partir do Princípio da Mínima Energia Potencial Total e o sistema não linear de equações resultante é resolvido utilizando-se o procedimento iterativo de Newton-Raphson. As ações externas podem ser introduzidas ao sistema de forma total ou incremental e a contribuição das fibras para a energia do sistema é adicionada na matriz global do problema. Os exemplos numéricos testados validam e demonstram as potencialidades da formulação proposta. / In general, the Finite Element (FE) formulations available in the literature for the analysis of fibre reinforced laminated shells replace the original heterogeneous medium by an equivalent homogeneous one, which makes difficult the identification of fiber-matrix stress distribution, or require that the finite element mesh is arranged in a way that the fibre finite element nodes coincide with the shell finite element ones, which is a very restrictive requirement and increases the number of degrees of freedom of the resulting system of equations. In this sense, the objective of this thesis is to develop a formulation for the inclusion of long and random short fibres in any layer of FE laminated anisotropic shells developing large displacement and rotations without increasing the number of degrees of freedom and the necessity of matching nodes in the discretization of the fibre and the matrix. In this formulation, the triangular laminated shell finite element used to discretize the matrix has ten nodes and seven degrees of freedom per node, that are, three translations, three components of a generalized vector and the linear rate of strain variation along the thickness. The curved fibres, long or random short, are introduced in any layer of the laminate shell by means of kinematic relation to ensure its adherence to the matrix without introducing new degrees of freedom in the resulting system of equations. To discretize them, any order one-dimensional finite elements with three degrees of freedom per node are used. These fibres elements are consistently considered by Geometric nonlinearity. All involved variables are written with respect to the initial configuration of the body, characterizing the Total Lagrangian description. To model the behavior of the material we use the Saint-VenantKirchhoff Constitutive Law that relates linearly the second Piolla-Kirchhoff stress tensor and Green-Lagrange strain tensor. The equilibrium is achieved from the Principle of Minimum Potential Energy and the non-linear system of equations is solved by the Newton-Raphson iterative procedure. External loads may be introduced to the system by one or various steps and the contribution of fibres to the energy of the system is added to the global matrix of the problem. The numerical examples validate and demonstrate the potential of the proposed formulation.

No description available.

In this work, experimental and theoretical approaches are applied to the study of chemical reaction dynamics. In Chapter 2, two applications of transition state theory are presented: (1) Application of microcanonical transition state theory to determine the rate constant of dissociation of C2F3I after π∗ ← π excitation. It was found that this reaction has a very fast rate constant and thus is a promising system for testing the statistical assumption of molecular reaction dynamics. (2) A general rate constant expression for the reaction of atoms and molecules at surfaces was derived within the statistical framework of flexible transition state theory. In Chapter 4, a computationally efficient TDDFT approach was found to produce useful potential energy surface landscapes for application to non-adiabatic predissociative dynamics of the molecule CS2 after excitation from the ground state to the singlet C-state. In Chapter 5, ultrafast experimental results of excitation of CS2 to the predissociative neutral singlet C-state is presented. The bandwidth of the excitation laser was carefully tuned to span a two-component scattering resonance with each component differently evolving electronically with respect to excited state character during the quasi-bound oscillation. Scalar time-resolved photoelectron spectra (TRPES) and vector time-resolved photoelectron angular distribution (TRPAD) observables were recorded during the predissociation. The TRPES yield of photoelectrons was found to oscillate with a quantum beat pattern for the photoelectrons corresponding to ionization to the vibrationless cation ground state; this beat pattern was obscured for photoelectron energies corresponding to ionization from the vibrationally excited CS2 cation. The TRPAD data was recorded for two general molecular ensemble cases: with and without a pre-excitation alignment laser pulse. It was found that in the case of ensemble alignment (Chapter 6), the “molecular frame” TRPAD (i.e. TRMFPAD) was able to image the purely valence electronic dynamics of the evolving CS2 C-state. The unaligned ensemble TRPAD observable suffers from excessive orientational averaging and was unable to observe the quantum beat. Engineering efforts were also undertaken to eliminate scattered light background signal (Chapter 7, Appendix A) and improve laser stability as a function of ambient pressure (Appendix B) for TRMFPAD experiments. / Thesis (Ph.D, Chemistry) -- Queen's University, 2012-09-11 22:18:20.89