Steel Catenary Riser (SCR) is a popular solution for a floating production facility in the deep and ultra-deep ocean. In the analysis of SCR, the behavioral characteristics are investigated to check the failure modes by assessing the magnitude and the frequency of the stress and strain which SCR goes through in time series. SCR is affected by the motions of connected floating production facility and exciting environmental loads. The driven force and motion of SCR has an interaction with seabed soil which represents the stiffness and friction force where SCR touches the seabed. Dynamic response of SCR is primarily caused by the coupled motion of floating structure. The displacement of floating structure is often large and fast enough to cause short cycles of negative and positive tension on SCR. The interaction between SCR and seabed is concentrated at the touchdown zone resulting into the compression and corresponding deformation of pipeline at the position. This paper presents models of floating production facilities and connected mooring lines and SCRs in 100-year hurricane environmental loads and seabed, focusing on the motional characteristics of SCR at the touchdown zone. In time series simulation, the model of SCR is first analyzed as a pipeline with indefinite elasticity so that the SCR does not fail even if the exciting loads exceed the property limit of SCR. Then the SCR design is manually checked using criteria for each failure mode to estimate the integrity.

The reaction mechanism for the selective catalytic reduction (SCR) of nitric oxide by ammonia on (010) V2O5 surface represented by a V2O9H8 cluster was simulated by density functional theory (DFT) calculations. The computations indicated that SCR reaction consisted of three main parts. In the first part ammonia activation on Br&oslash / nsted acidic V-OH site as NH4+ species by a nonactivated process takes place. The second part includes the interaction of NO with pre-adsorbed NH4 + species to eventually form nitrosamide (NH2NO). The rate limiting step for this part as well as for the total SCR reaction is identified as NH3NHO formation reaction. The last part consists of the decomposition of NH2NO on the cluster which takes advantage of a hydrogen transfer mechanism between the active V=O and V-OH groups. Water and ammonia adsorption and dissociation are investigated on (101) and (001) anatase surfaces both represented by totally fixed and partially relaxed Ti2O9H10 clusters. Adsorption of H2O and NH3 by H-bonding on previously H2O and NH3 dissociated systems are also considered. By use of a (001) relaxed Ti2O9H10 cluster, the role of anatase support on SCR reaction is investigated. Since NH2NO formation on Ti2O9H10 cluster requires lower activation barriers than on V2O5 surface, it is proposed that the role of titanium dioxide on SCR reaction could be forming NH2NO. The role of vanadium oxide is crucial in terms of dissociating this product into H2O and N2. Finally, NH3 adsorption is studied on a V2TiO14H14 cluster which represents a model for vanadia/titania surface.

The controls for a parallel hybrid electric truck are optimized using numerical optimal control. Trade-offs between catalyst light-off times, NOx emission and fuel consumption have been investigated for cold starts at two operating points, as well as temperature differences between conventional and hybrid powertrains during WHTC (World Harmonized Transient Cycle). A model describing the temperature dynamics of the aftertreatment system is implemented as well as temperature-based deNOx performance for both Cu-Zeolite and Fe-Zeolite catalysts. Control is performed in a piecewise linear fashion, resulting in a total of 23 states including control signals. It is shown that high temperatures can be a larger threat to catalyst performance when running the WHTC than low temperatures, for both conventional and hybrid powertrains. Furthermore, decreasing the light-off time of the catalyst does not always lead to decreased NOx emission, instead there is a trade-off between light-off time and NOx emission. It is found that there are controls that will realize decreased NOx emission for a hybrid truck during cold starts at the expense of increased fuel consumption.

abstract: ABSTRACT The heat recovery steam generator (HRSG) is a key component of Combined Cycle Power Plants (CCPP). The exhaust (flue gas) from the CCPP gas turbine flows through the HRSG − this gas typically contains a high concentration of NO and cannot be discharged directly to the atmosphere because of environmental restrictions. In the HRSG, one method of reducing the flue gas NO concentration is to inject ammonia into the gas at a plane upstream of the Selective Catalytic Reduction (SCR) unit through an injection grid (AIG); the SCR is where the NO is reduced to N2 and H2O. The amount and spatial distribution of the injected ammonia are key considerations for NO reduction while using the minimum possible amount of ammonia. This work had three objectives. First, a flow network model of the Ammonia Flow Control Unit (AFCU) was to be developed to calculate the quantity of ammonia released into the flue gas from each AIG perforation. Second, CFD simulation of the flue gas flow was to be performed to obtain the velocity, temperature, and species concentration fields in the gas upstream and downstream of the SCR. Finally, performance characteristics of the ammonia injection system were to be evaluated. All three objectives were reached. The AFCU was modeled using JAVA - with a graphical user interface provided for the user. The commercial software Fluent was used for CFD simulation. To evaluate the efficacy of the ammonia injection system in reducing the flue gas NO concentration, the twelve butterfly valves in the AFCU ammonia delivery piping (risers) were throttled by various degrees in the model and the NO concentration distribution computed for each operational scenario. When the valves were kept fully open, it was found that it led to a more uniform reduction in NO concentration compared to throttling the valves such that the riser flows were equal. Additionally, the SCR catalyst was consumed somewhat more uniformly, and ammonia slip (ammonia not consumed in reaction) was found lower. The ammonia use could be decreased by 10 percent while maintaining the NO concentration limit in the flue gas exhausting into the atmosphere. / Dissertation/Thesis / M.S. Mechanical Engineering 2011

Dans l’industrie de la micro-électronique, les efforts à fournir pour les nouvelles applications développées deviennent de plus en plus contraignants et difficiles à supporter en terme de coût. Les agressions provenant des décharges électrostatiques (ESD) générées par l’environnement direct sur les puces constituent un facteur important de la chute de rendement et donc des coûts. Ces difficultés s’ajoutent aux limites physiques plus strictes pour fabriquer des transistors lorsque l’on aborde des échelles nanométriques. La technologie Silicium sur Isolant (SOI) a été développée afin de contourner cette difficulté, mais l’intégration des protections ESD limite son émergence du fait de la complexité de la mise au point et du développement d’un réseau de protection pour la puce.L’objectif annoncé de ce travail de recherche, effectué en collaboration entre STMicroelectronics le CEA et l’IMEP est d’évaluer les caractéristiques principales de la technologie pour la protection contre les décharges et de proposer une stratégie innovante de protection adaptée au SOI. En effet, à partir de résultats expérimentaux, nous avons pu constater que l’oxyde enterré, le BOX, limite les performances en robustesse et diminue la fenêtre de conception pour le déclenchement des protections. Pour y remédier, une structure commandée bidirectionnelle a été développée sur PDSOI afin de faciliter la dissipation thermique et améliorer la robustesse. Pour prolonger cette solution sur technologie FDSOI, une étude approfondie sur le thyristor afin a été menée afin de porter cette solution. L’analyse de simulation 3D et de résultats silicium ont permis de proposer une stratégie de protections innovantes pour le thyristor sur FDSOI. / In the microelectronics industry, the fabrication process for advanced technological nodes becomes more and more cumbersome and limiting in terms of cost. The electrostatic discharges (ESD) generated by the direct environment affect the circuits and constitute an important factor for the decrease of the yield and thus result in an increase of the costs. Apart from these difficulties, there are also issues arising from the physical limits of transistor integration when reaching the nanoscale.The Silicon on Insulator (SOI) technology was developed in order to bypass this difficulty. However, the integration of ESD protections limits its emergence due to the development complexity and the protection circuit needed. The goal of this work which was a collaboration between STMicroelectronics, CEA and IMEP was to evaluate the principal characteristics of this technology for electrostatic discharge protection and propose a novel protection strategy adapted for SOI.In fact, we were able to confirm from experimental results that the buried oxide (BOX) limits the performances in terms of robustness and narrows the window of conception for the triggering of the protections. A commanded bidirectional structure was developed on PDSOI and proposed as a solution to facilitate the thermal dissipation and improve the robustness.In order to extend this solution on FDSOI technology, a detailed study on the thyristor was performed. Analysis of the 3D simulations and experimental results permitted to propose an innovative strategy for ESD protections on FDSOI.

This master's thesis deals with current situation of medical waste management in the Czech Republic and it also analyzes the quality of existing units for thermal treatment of the medical waste. In the second part of the thesis, available off-gas cleaning methods were described as well as the emission limits for waste incineration, which correspond to the legislative regulations effective in the Czech Republic. These emission limits are considered as input data for off-gas cleaning system design. In the main part of this thesis, two technological solutions of off-gas cleaning methods for Up-to-Date medical waste incineration unit were designed. The unit is designed for energy utilization of 1400 tons of medical waste accumulated during one year in a regional hospital of model region. From given input parameters, two appropriate apparatus concepts were created. After that, both concepts were evaluated either form energetic point of view as well as from material one. From these evaluations, key apparatuses of both concepts were designed which provided necessary design dimensions for further investment price estimation of each individual key apparatus. In the conclusion of this thesis, the best solution of an off-gas cleaning method was picked according to the comparison of operating and investment costs.

This diploma thesis deals with selected abatement techniques of nitrogen oxides (NOx) developed for large combustion plants. The first part describes selected NOx, their properties and explains the formation during combustion. Furthermore, there is an analysis of current legal legislation regulating the issue of emission limits. The third part presents selected primary and secondary measures that are widely used. The emphasis is placed on the description of selective catalytic (SCR) and non-catalytic reduction (SNCR). Finally, the basic design of these technologies for model combustion equipment is performed. The consumption of reducing medium and the volume of the catalyst for the mentioned techniques are calculated here. The estimate of selected operating and investment costs is a part of the basic scheme.

Electrostatic Discharge (ESD), an event of a sudden transfer of electrons between two bodies at different potentials, happens commonly throughout nature. When such even occurs on integrated circuits (ICs), ICs will be damaged and failures result. As the evolution of semiconductor technologies, increasing usage of automated equipments and the emerging of more and more complex circuit applications, ICs are more sensitive to ESD strikes. Main ESD events occurring in semiconductor industry have been standardized as human body model (HBM), machine model (MM), charged device model (CDM) and international electrotechnical commission model (IEC) for control, monitor and test. In additional to the environmental control of ESD events during manufacturing, shipping and assembly, incorporating on-chip ESD protection circuits inside ICs is another effective solution to reduce the ESD-induced damage. This dissertation presents design, characterization, integration and compact modeling of novel silicon controlled rectifier (SCR)-based devices for on-chip ESD protection. The SCR-based device with a snapback characteristic has long been used to form a VSS-based protection scheme for on-chip ESD protection over a broad rang of technologies because of its low on-resistance, high failure current and the best area efficiency. The ESD design window of the snapback device is defined by the maximum power supply voltage as the low edge and the minimum internal circuitry breakdown voltage as the high edge. The downscaling of semiconductor technology keeps on squeezing the design window of on-chip ESD protection. For the submicron process and below, the turn-on voltage and sustain voltage of ESD protection cell should be lower than 10 V and higher than 5 V, respectively, to avoid core circuit damages and latch-up issue. This presents a big challenge to device/circuit engineers. Meanwhile, the high voltage technologies push the design window to another tough range whose sustain voltage, 45 V for instance, is hard for most snapback ESD devices to reach. Based on the in-depth elaborating on the principle of SCR-based devices, this dissertation first presents a novel unassisted, low trigger- and high holding-voltage SCR (uSCR) which can fit into the aforesaid ESD design window without involving any extra assistant circuitry to realize an area-efficient on-chip ESD protection for low voltage applications. The on-chip integration case is studied to verify the protection effectiveness of the design. Subsequently, this dissertation illustrate the development of a new high holding current SCR (HHC-SCR) device for high voltage ESD protection with increasing the sustain current, not the sustain voltage, of the SCR device to the latchup-immune level to avoid sacrificing the ESD protection robustness of the device. The ESD protection cells have been designed either by using technology computer aided design (TCAD) tools or through trial-and-error iterations, which is cost- or time-consuming or both. Also, the interaction of ESD protection cells and core circuits need to be identified and minimized at pre-silicon stage. It is highly desired to design and evaluate the ESD protection cell using simulation program with integrated circuit emphasis (SPICE)-like circuit simulation by employing compact models in circuit simulators. And the compact model also need to predict the response of ESD protection cells to very fast transient ESD events such as CDM event since it is a major ESD failure mode. The compact model for SCR-based device is not widely available. This dissertation develops a macromodeling approach to build a comprehensive SCR compact model for CDM ESD simulation of complete I/O circuit. This modeling approach offers simplicity, wide availability and compatibility with most commercial simulators by taking advantage of using the advanced BJT model, Vertical Bipolar Inter-Company (VBIC) model. SPICE Gummel-Poon (SGP) model has served the ICs industry well for over 20 years while it is not sufficiently accurate when using SGP model to build a compact model for ESD protection SCR. This dissertation seeks to compare the difference of SCR compact model built by using VBIC and conventional SGP in order to point out the important features of VBIC model for building an accurate and easy-CAD implement SCR model and explain why from device physics and model theory perspectives.

Background During development, endothelial cells acquire mesenchymal-like properties to migrate and facilitate normal vascular formation. This process of transformation is known as endothelial to mesenchymal transition (EndMT) and has also been implicated in diseases like vascular pathologies contributing to endothelial inflammation, atherosclerosis and tumour angiogenesis. The Angiomotin family of scaffold proteins play a role in transducing mechanical force at cell junctions. Of this family, Angiomotin-Like 2 (AmotL2) localises to endothelial cell junctions and was recently found to play a role in regulating endothelial cell mechanosensing and inflammation. Methods/Materials Primary human endothelial cell lines (HUVEC) were cultured and manipulated in vitro to investigate the role of AmotL2 in EndMT. Lentiviral short hairpin RNA interference was employed in AmotL2-loss-of-function studies, (produced using HEK - Human Embryonic Kidney - cells) to generate knockdown(kd) cells. Western blotting (WB) was used to assess AmotL2 depletion and changes in protein expression of key EndMT markers. qPCR was performed to look at the same at a transcriptional level. Immunofluorescent staining and confocal imaging were performed to validate WB and qPCR results as well as to study protein localisation. Results AmotL2 was found to regulate Snail1 and N-cadherin at both protein and mRNA levels. Morphological findings displayed the AmotL2kd cells to be elongated, deviating from the regular cobblestone morphology observed in control cells. An increase in scaffold protein levels was observed in the AmotL2 kd samples. Similar results were seen in qPCR data where increased mRNA expression was observed in the AmotL2 kd samples for the same targets. On analysis of IF image data, more nuclear staining was observed in the kd samples. qPCR analysis done on samples treated with TGF-β, exhibited an increase in mRNA expression of targets involved in the EndMT pathway in the treatment samples against the controls. Conclusion The results suggest that AmotL2 plays a role in EndMT by affecting the transcription factors and proteins involved in the pathway, which leads to changing morphology and behaviour of the cells. Looking into more targets involved in EndMT may give us a better understanding of how this process leads to diseases like atherosclerosis and tumour angiogenesis.

Lien vers le GitHub contenant tous les outils programmés dans le cadre du mémoire : https://github.com/neurok8050/eda-optimisation-processing-tool / L’activité électrodermale (EDA), particulièrement la skin conductance response (SCR), est un signal psychophysiologique fréquemment utilisé en recherche en psychologie et en neuroscience cognitive. L’utilisation de l’EDA entraîne son lot de défis particulièrement son prétraitement. En effet, encore très peu de recherches effectuent un prétraitement adéquat. Notre objectif est donc de promouvoir l’utilisation du prétraitement du signal SCR et de proposer des recommandations pour les chercheurs en fournissant des données sur l’impact du prétraitement sur la capacité à discriminer les SCR entre deux conditions expérimentales. En utilisant des travaux similaires, nous avons testé les effets de combinaisons de prétraitement utilisant différentes méthodes de filtrage, différentes méthodes de remise à l’échelle, l’inclusion d’une étape de détection automatique des artefacts de mouvement et en utilisant différentes métriques opérationnalistes (le peak-scoring (PS) et l’aire sous la courbe (AUC)) et d’approches par modèle. Enfin, nous avons testé si une seule combinaison de filtrage pourrait être utilisée avec différents jeux de données ou si le prétraitement devrait plutôt être ajusté individuellement à chaque jeu de données. Nos résultats suggèrent que 1) l’inclusion d’une étape de détection automatique des artefacts de mouvements n’affecte pas significativement la capacité à discriminer entre deux conditions expérimentales, 2) l’approche par modèle semble être un peu meilleure à discriminer entre deux conditions expérimentales et 3) la meilleure combinaison de prétraitement semble variée en fonction du jeu de données utilisé. Les données et outils présentés dans ce mémoire devraient permettre de promouvoir et faciliter le prétraitement du signal SCR. / Electrodermal activity (EDA), particularly the skin conductance response (SCR) is a psychophysiological signal frequently used in research in psychology and in cognitive neuroscience. Nevertheless, using EDA comes with some challenges notably in regard to its preprocessing. Indeed, very few research teams adequately preprocess their data. Our objective is to promote the implementation of SCR preprocessing and to offer some recommendations to researchers by providing some data on the effect of preprocessing on the SCR ability to discriminate between two experimental conditions. Based on similar work, we have tested the effect of preprocessing combinations using different filtering methods, different rescaling methods, the inclusion of an automatic motion detection step while using different operationalist metrics (peak-scoring (PS) and area under the curve (AUC)) and different model-based approach metrics. Finally, we tested if only one combination could be used across different datasets or if the preprocessing should be optimized individually to each dataset. Our results show that 1) the inclusion of the automatic motion detection step did not significantly impact the ability to discriminate between two experimental conditions, 2) the model-based approach seems to be slightly better at discriminating between two experimental conditions and 3) the best combination of preprocessing seems to vary between different datasets. The data and tools presented in this master thesis should promote and facilitate SCR signal preprocessing.