Os sistemas de controle solar auxiliam no controle da radiação solar incidente no envoltório, e, de acordo com a NBR 15220-3, é recomendável seu uso para a zona bioclimática 3, na cidade de Porto Alegre. Assim, com a ação de retrofitting, é possível utilizar os sistemas de controle solar como modo de adaptar o envoltório das edificações ao clima local e aos padrões de consumo atuais. Dessa forma, o retrofitting do envoltório pode contribuir com a redução do consumo energético e a dependência de sistemas de refrigeração e aquecimento mecânico. Logo, o objetivo da dissertação é qualificar e quantificar energeticamente os sistemas de controle solar com vistas à redução do consumo energético nos ambientes construídos. Um estudo de caso foi realizado na cidade de Porto Alegre, onde um edifício foi selecionado perante um conjunto de edificações existentes. Com o auxílio de um método expedito de cálculo energético, foi realizada a avaliação energética do envoltório da edificação atual e do seu retrofitting proposto. A edificação passou de nível energético E para nível A, comprovando o êxito do estudo de retrofitting aplicado. A pesquisa concluiu que, alinhado com o encontrado na revisão da literatura, as edificações com grandes aberturas orientadas para oeste são um equívoco de projeto no clima de Porto Alegre e que as ações de retrofitting são uma alternativa de adaptação ao clima local, tornando os edifícios eficientes energeticamente. / Shading systems help to control the incident solar radiation on the envelope, and, according to NBR 15220-3, its use is recommended for the bioclimatic zone 3, in the city of Porto Alegre. Hence, with retrofitting, it is possible to use shading systems as a way of adapting the building envelope to the local climate and current consumption patterns. Thus, the retrofitting of the envelope can contribute to the reduction of the energy consumption and of the dependence on systems of refrigeration and mechanical heating. Therefore, the objective of this dissertation is to qualify and quantify the energy of shading systems in order to reduce energy consumption in built environments. Thus, a case study was conducted in the city of Porto Alegre, where a building was selected from a set of existing buildings. We performed an energetic evaluation of current envelope of buildings and its proposed retrofitting by using a facilitated method for energy calculation. The buildings moved from energy level E to level A, proving the success of the study on the applied retrofitting. We conclude that, as also shown in literature review; buildings with large openings oriented to the west in Porto Alegre are a design misconception due to the city’s climate. Thus, retrofitting actions are alternative ways to adapt to the local climate so that buildings are energy efficient.

The baroreflex is a well-studied physiological mechanism that provides instantaneous nerve impulses to higher brain centers about fluctuations in blood pressure. Located within the aortic arch and carotid sinuses, the baroreceptors are mechanosensitive stretch receptors activated by physical distention. When stretched by elevated blood pressure, the baroreflex is activated and serves to reduce sympathetic nerve activity through increased parasympathetic nerve output, ultimately reducing heart rate, contractility and total vascular peripheral resistance. Therefore, through physical perturbation, the baroreflex can be activated and ensuing physiological changes result. Several medical devices have been developed to treat and manage cardiovascular diseases that are affected by blood pressure dysregulation. A significant portion of devices have their mechanistic application at locations at or near the aortic and carotid baroreceptors, which results in alterations of baroreflex activation. This literature review serves to highlight three clinically important cardiovascular devices and the effects they have on the baroreflex through a summarized review of published work in the scientific community. Intra-aortic balloon pumps, left ventricular assist devices and carotid sinus stimulators are cardiovascular devices that have shown promising development and clinical impact since each devices’ initial application in research trials. Each device has been thoroughly reviewed here and the impact that each device has on blood pressure regulation has been investigated via available published work. Results from a limited number of studies have shown that each device has a definite effect on baroreflex activation and subsequent changes in autonomic nervous system function. Modifications in blood pressure through device use appear to be a potential therapeutic approach to managing pathophysiological states, including hypertension and heart failure. Hypertension and heart failure will be discussed in greater detail, reviewing current approaches to disease management and care. The results from the available publications surrounding device use are specific to certain diseases, however, they are also quite generalizable in the sense that these results have shown an overall true effect on blood pressure modification by the baroreflex. Conclusions established from this literature review are that although promising work has been recognized through studying these cardiovascular devices and their effects on blood pressure regulation, much research and development is still needed in order to gain a better understanding of device use and impact in the clinical setting.

L'objectif de cette thèse est d'étudier certains aspects des réseaux coopératifs sans fils à l'aide de la géométrie stochastique. Ça permets de considérer la distribution spatiale aléatoire des utilisateurs et les effets adverses de leur interaction, comme l’interférence.Nous étudions la performance, évaluée par la probabilité d'outage, atteignable dans un canal de relai full-duplex quand les nœuds opèrent dans un grand réseau sans fils où les émetteurs interférants sont modelés avec un processus ponctuel de Poisson homogène. Nous trouvons la probabilité d'outage des protocoles décodez-et-renvoyez (decode-and-forward, DF), et comprimez-et-renvoyez (compress-and-forward) et nous faisons une comparaison avec une transmission point à point et un protocole DF half-duplex. Ensuite, nous étudions une situation plus générale dans laquelle les émetteurs qui causent l'interférence peuvent aussi utiliser un relai ou faire des transmissions point à point. Nous étudions la relation entre les avantages de la cooperation et l'interférence qu'elle même génère.Dans la deuxième partie nous étudions la performance des stratégies de partage de vidéos par communications entre dispositifs mobiles (device-to-device, D2D) hors de la bande des communications cellulaires. Nous étudions la fraction des demandes de vidéos qui peuvent être satisfaites par D2D, c’est-à-dire, par le biais des émissions locales, plutôt que par la station de base. Pour étudier ce problème, nous introduisons un modèle de processus ponctuel, qui considère la stratégie de stockage dans les utilisateurs, le problème de comment lier les utilisateurs et les problèmes de la transmission et coordination entre les utilisateurs. / The main goal of this work is to study cooperative aspects of large wireless networks from the perspective of stochastic geometry. This allows the consideration of important effects such as the random spatial distribution of nodes, as well as the effects of interference and interference correlation at receivers, which are not possible when a single link is considered in isolation.First, some aspects of the performance of the relay channel in the context of a large wireless network are considered. Mainly, the performance, in terms of outage probability (OP), of a single full-duplex relay channel utilizing decode-and-forward (DF) or compress-and-forward, when the interference is generated by uniform spatial deployment of nodes, modeled as a Poisson point process. The OP performance of these two protocols is compared with a point-to-point transmission and with a half-duplex DF protocol. Afterwards, the case in which more than one transmitter in the network may use a relay is considered. The effects of cooperation versus interference are studied, when the users use either full-duplex DF, or point-to-point transmissions. In a second phase, this work explores the advantages that could be obtained through out-of-band device-to-device (D2D) video file exchanges in cellular networks. These advantages are measured in terms of the fraction of requests that can be served in a time-block through D2D, thus avoiding a downlink file transfer from the base station. For this, a stochastic geometry framework is introduced, in which the user file-caching policy, user pairing strategy, and link quality and scheduling issues are considered.

Le problème de coloration de graphe est un problème NP-complet particulièrement étudié, qui permet de modéliser de problèmes dans des domaines variés. Dans cette thèse, de nouveaux algorithmes exacts basés sur une étude de la structure du graphe sont proposés. Ce travail s'appuie sur l'algorithme « Total solutions Exact graph Coloring » (TexaCol) qui construit toutes les solutions en exploitant l'ensemble des cliques d'un graphe. Deux algorithmes exacts, « Partial best solutions Exact graph Coloring » (PexaCol) et « All best solutions Exact graph Coloring » (AexaCol), sont présentés ici pour construire certaines solutions optimales ou toutes les meilleures solutions. Ces deux algorithmes utilisent la méthode de backtracking, dans laquelle ils ne choisissent que les sous-ensembles de meilleurs solutions pour continuer la coloration. L’analyse de résultat montre que PexaCol et AexaCol sont capables de traiter des graphes plus grands que TexaCol. Mais surtout, AexaCol trouve toutes les meilleures solutions significativement plus vite que TexaCol ainsi que le solveur Gurobi, qui sont utilisés comme référence.La téléphonie mobile est un domaine en plein essor qui peut s'appuyer sur une modélisation à base de graphes. Actuellement, les techniques de type « Device-to-Device » (D2D) prennent une place importante dans les réseaux mobiles. L’allocation de ressource constitue l'un des principaux problèmes en matière de performance. Pour assigner efficacement une ressource radio à une paire D2D dans le système Long-Term Evolution (LTE), un schéma systématique d'allocation de ressources est proposé dans cette thèse. Il est basé sur une clusturisation des liens D2D, et permet de prendre en compte à la fois l'allocation inter-cluster et intra-cluster des ressources. En déterminant les zones d'interférence, le problème d'allocation des ressources inter-cluster est formulé comme un problème de coloration de graphe dynamique. Un algorithme de coloration de graphe dynamique est ainsi proposé, basé sur PexaCol. Cet algorithme peut assigner les ressources radio aux clusters qui sont générés ou supprimés dynamiquement. L’analyse numérique montre que cet algorithme assure une bonne performance en termes d'utilisation des ressources, de temps d’exécution et d'adaptabilité. Concernant le problème d’allocation de ressources inter-cluster, une méthode fondée sur la topologie est proposée, intégrant naturellement l'allocation de puissance et l’allocation de Resource Block (RB). Pour simplifier ce problème d'allocation de ressources, la meilleure topologie est choisie à chaque étape, celle qui permet d'obtenir le meilleur débit en utilisant le moins de RBs. A partir de ce procédé, quatre algorithmes d'optimisation sont proposés: l’algorithme glouton statique, PexaCol statique, PexaCol dynamique et PexaCol dynamique approximatif. L'analyse des résultats montre que pour les petits clusters, les versions statiques et dynamiques de PexaCol permettent d'obtenir un index d’optimisation maximal en choisissant la meilleure topologie locale pour chaque noeud. A l'opposé, les algorithmes "glouton statique" et "PexaCol dynamique approximatif" permettent d'obtenir une solution sous-optimale pour l'optimisation locale avec une complexité moindre. Pour les grands clusters, avec certaine séquence de la coloration, le PexaCol dynamique approximatif est mieux que l’algorithme glouton statique pour l’index d’optimisation pendant un temps d’exécution acceptable. / Graph coloring problem is a famous NP-complete problem, which has extensive applications. In the thesis, new exact graph coloring algorithms are researched from a graph structure point of view. Based on Total solutions Exact graph Coloring algorithm (TexaCol) which is capable of getting all coloring solution subsets for each subgraph, two other exact algorithms, Partial best solutions Exact graph Coloring algorithm (PexaCol) and All best solutions Exact graph Coloring algorithm (AexaCol), are presented to get multiple best solutions. These two algorithms utilize the backtracking method, in which they only choose the best solution subset each step to continue the coloring until partial or all best solutions are obtained. The result analysis shows that PexaCol and AexaCol can deal with larger graphs than TexaCol and especially, AexaCol runs much faster than TexaCol and the solver Gurobi to get all best solutions.Device-to-Device (D2D) is a promising technique for the future mobile networks, such as 5th generation wireless systems (5G), and the resource allocation is one of the most crucial problems for its performance. In order to efficiently allocate radio resource for D2D links in Long-Term Evolution (LTE) system, a systematic resource allocation scheme is proposed based on D2D clusters, including the inter-cluster resource allocation and the intra-cluster resource allocation. With the cluster interference range, the inter-cluster resource allocation problem is formulated as a dynamic graph coloring problem, and a dynamic graph coloring algorithm is designed based on PexaCol. This algorithm is able to allocate radio resource to clusters while they are dynamically generated and deleted. The numerical analysis results show that this algorithm has good performance in resource utilization, runtime and scalability.For the intra-cluster resource allocation problem, a topology-based resource allocation method is designed naturally combining power allocation with Resource Block (RB) allocation. To simplify this associated optimization problem, a local optimal method is proposed, in which the best topology is chosen each step achieving the maximal throughput with the minimum number of assigned RBs. With respect to this method, four algorithms are presented: static greedy, static PexaCol, dynamic PexaCol and dynamic PexaCol approximate. Result analysis shows that for small-scale clusters, static PexaCol and dynamic PexaCol are capable of getting a maximal optimization index by locally choosing the best topology for each node while static greedy and dynamic PexaCol approximate are able to get the suboptimal solution for the local optimization with much lower complexity. For large-scale clusters, giving certain treating sequences, the dynamic PexaCol approximate performs better than static greedy regarding the optimization index within an acceptable runtime.

The performance of flocculants used in the solid-liquid separation of red mud is often compromised by the methods used to mix the fast acting polymers into the slurry. A simple model of the relationship between flocculant performance and intensity of mixing is proposed and a device for mixing flocculant and slurry has been developed on the basis of the model.The intensity of mixing at the point of distributing the flocculant into the slurry is arguably the most important variable influencing the final flocculant performance. This relationship is established using data from flocculation tests in an agitated tank. The flocculant performance is monitored using an optical sensor and the settling rate of the solid-liquid interface is used as a comparison for the optical sensor. The difficulties, errors and merits of the optical sensor to study the flocculation of red mud and automatic control of flocculation processes are also assessed.The mixing device is connected to a pipe for flocculation tests with red mud. For the tests carried out, a high level of flocculation was recorded.The mixing device combines the flocculant and slurry as thin annular jets directed into one another. The opening for the slurry jet can be altered to provide a variation of the mixing that is achieved. The capability of the device to mix rapidly has been assessed using the diazo coupling reactions between l-naphthol and diazotised sulphanilic acid in alkaline, aqueous solution at room temperature. Variables studied included flow rate and slurry jet opening. Better mixing was indicated at higher flow rates and at reduced jet opening. The use of the diazo coupling reactions for studying micromixing is also assessed.

Ruminants possess a unique digestive system. Using the high metabolic potential of the symbiotic microflora of the rumen, ruminants are capable of digesting plant material and obtaining nutrients and energy from this process. Because of the ruminal fermentation, the most bioactives are not stable in the harsh ruminal environment. Therefore there is a need to improve the bioavailability of a bioactive by protecting it from the ruminal digestion. The formulation of protected bioactive can be delivered in the rumen in a controlled manner and over a long period of time. In this project the degree of rumen protection was estimated using model substrates (sugar pellets and granules). These materials were coated with the pH-sensitive polymer Eudragit E. The model bioactive (phloridizin) was coated using the coating methodology adopted from exploratory studies with model substrates. The bioavailability of protected (coated) phloridizin was assessed by administering directly into the abomasum of fistulated cows. Formulation of protected phloridizin was used to demonstrate the feasibility of bioactive controlled delivery based on ART ( Active Rumen Technology ). This technology uses an elevated gas pressure created by a hydrogen-producing cell to drive a plunger which extrudes bioactive formulation from an intraruminal controlled-release device. Four groups of devices filled with formulation containing different amounts of protected phloridizin were tested. The bioactive was released in a controlled manner over several days. The formulation release profiles were reproducible suggesting that in principle the technology can be further developed to use in a commercial sense or for research purposes. The limitations of the technology, including formulation issues and gas diffusion through barrel walls, were identified.

Thesis (M.A.)--Georgia State University, 2007. / Title from file title page. Lindsey L. Cohen, committee chair;Lisa Armistead, Chris Henrich, committee members. Electronic text (67 p. : ill.) : digital, PDF file. Description based on contents viewed Dec. 13, 2007. Includes bibliographical references (p. 42-49) and index.

Performance and manufacturability are two important issues that must be taken into account during MEMS design. Existing MEMS design models or systems follow a process-driven design paradigm, that is, design starts from the specification of process sequence or the customization of foundry-ready process template. There has been essentially no methodology or model that supports generic, high-level design synthesis for MEMS conceptual design. As a result, there lacks a basis for specifying the initial process sequences. To address this problem, this paper proposes a performance-driven, microfabrication-oriented methodology for MEMS conceptual design. A unified behaviour representation method is proposed which incorporates information of both physical interactions and chemical/biological/other reactions. Based on this method, a behavioural process based design synthesis model is proposed, which exploits multidisciplinary phenomena for design solutions, including both the structural components and their configuration for the MEMS device, as well as the necessary substances for the chemical/biological/other reactions. The model supports both forward and backward synthetic search for suitable phenomena. To ensure manufacturability, a strategy of using microfabrication-oriented phenomena as design knowledge is proposed, where the phenomena are developed from existing MEMS devices that have associated MEMS-specific microfabrication processes or foundry-ready process templates. To test the applicability of the proposed methodology, the paper also studies microfluidic device design and uses a micro-pump design for the case study. / Singapore-MIT Alliance (SMA)

High tunability and low loss tangent of ferroelectric thinfilms offer unique opportunity for the development of variousmicrowave devices. Silver tantalate niobate, which showsexcellent microwave properties, was selected for this study.Ag(Ta,Nb)O3(ATN) showed week dielectric dispersion in a widefrequency range from 1 kHz up to 100 GHz, negligible losses upto 30 GHz, and ease to tailor paraelectric state in a widetemperature range by Ta:Nb ratio. This thesis is mainly based on the synthesis andcharacterization of niobate ferroelectric ATN thin films. Thinfilms for various measurements were prepared by pulsed laserdeposition and rf-magnetron sputtering techniques. X-ray diffraction (XRD) pattern show that ATN/Pt80Ir20films have been found to be (001) preferentiallyoriented, while the epitaxial quality of ATN/LaAlO3heterostructures have been ascertained. Dielectricproperties were analyzed by measuring the relationship betweendielectric permittivity and frequency as well as dielectricpermittivity and temperature. Reliable tracing of theferroelectric hysteresis polarization versus electric loopsindicate the ferroelectric state in ATN films at temperaturebelow 125 K and yields the remanant polarization of 0.4µC/cm2@ 77 K. The fundamental current-voltage behavior in Ag(Ta,Nb)O3ferroelectric films was measured usingMe/Ag(Ta,Nb)O3/Pt80Ir20, Me = Pd, Au, Cr, and Al, vertical capacitivecell structures with different top electrodes. Various kinds ofconduction mechanisms such as Schottky emission, Poole-Frenkel,Fowler-Nordheim, and ionic conduction were classified. Finally, by fabricating interdigital capacitors on the oxidesubstrates, the characteristics and performances of Ag(Ta,Nb)O3varactors were examined. Au/Cr/ATN/LaAlO3interdigital capacitors exhibited loss tangent aslow as 0.0033 @ 1 MHz, weak frequency dispersion of 5.8 % in 1kHz to 1 MHz range, tunability as high as 16.4 %,K-factor (tunability/tanδ) higher than 48.

Cost competitiveness is a major driving force in the semiconductor industry. The processing cost of an individual die is directly proportional to its size. Advances in processing technology have shrunk the device sizes in wire-bonded chips, resulting in a smaller die core size. However, the space below wire-bond pads remains relatively underutilized because of the reliability concern that electrical loads transmitted during bonding can cause failures in the underlying devices. Recently, studies have attempted to improve the use of space below wire-bond pads. Hence, the circuits under pads (CUP) structure modified layout rules to include circuits structure under pads, was developed, and extensive qualification work is required to meet reliability standards. The main purpose of this paper is to investigate the damage caused by the wirebonding process of CUP devices on the in-line assembly packaging manufacture. The root cause of wirebonding failures analyzed were based on the CUP structure and several wire bond parameters; such as bonding force, ultrasonic current, bonding time period, capillary type, machine, and wafer source, which were also confirmed with the DOE/JMP engineer technique. Finally, results were also used to implement the corrective action and the assembly yield of CUP Device has been improved, successfully.