Dissertations / Theses on the topic 'Suspended time'

Total hip replacement (THR) has been one of the most successful surgeries in the 21st century. Ultra-high-molecular-weight-polyethylene (UHMWPE) shows favorable mechanical and tribological properties when used as a bearing surface material in THR. However, produced UHMWPE wear particles challenge increasing the THR lifetimes. Bone loss (osteolysis) initiated by these wear particles is a major cause of total joint arthroplasty failure in both hip and knee prosthesis. In addition to improving the wear resistance of bearing surfaces to reduce wear, wear debris distribution mechanisms within the joint gap must also be thoroughly investigated. These particles distribute within lubricant and across the implant gap. Synovial fluid (SF) lubricates natural joints which is a viscoelastic non-Newtonian shear thinning fluid. The non-Newtonian behavior of SF is attributed to its hyaluronic acid (HA) content which is a linear biopolymer. The distribution patterns of wear particles within total joint replacement are affected by the special rheological behaviors of the SF, geometrical parameters, particle size and shape distribution and particle-fluid interactions. Therefore, understanding wear particles distribution pattern is pivotal to understand the mechanism and eventually minimizing third-body wear of the UHMWPE acetabular liner in THR. According to fluid mechanics forces, the size and density of wear particles suggests that wear particles follow lubricant movements. However, over a matter of hours, such particles show specific behaviors within viscoelastic fluid (not visible in Newtonian fluid) such as particle migration and string formation along the flow direction. The main aim of this project was to develop and validate an experimental method for assessing characteristics of HA and artificial SF solutions and behaviors of wear particles in a viscoelastic fluid flow. The effects of different parameters such as HA concentration, protein content, fluid flow types (steady, unsteady, etc.) and gap shapes on fluid behavior were quantified to fully understand such mechanisms. In this project, micro particle image velocimetry (micro-PIV) was applied as the quantitative flow visualization method. Pin-on-disk tribo-measurement was performed as a complimentary study to investigate the tribological behaviors of a UHMWPE pin rotating against a cobalt chromium molybdenum (CoCrMo) disk in the presence of HA solutions of various concentrations. This study was conducted to understand the effects of dynamic loading on lubricant performance relative to those of static loading. The results showed that under oscillatory flow conditions, strain levels, rates, and distributions are important parameters that affect the flow behaviors of HA solutions. Particle migration and alignment were affected by channel sizes, HA concentrations, flow types and the elastic instability of the solution. The tribological study results suggested that in the presence of HA, sinusoidal dynamic loading does not affect the frictional behaviors of UHMWPE moving against CoCrMo in comparison with static loading.
El reemplazo total de cadera (THR) ha sido una de las cirugías más exitosas en el siglo XXI. El polietileno de ultra alto peso molecular (UHMWPE) muestra propiedades mecánicas y tribológicas favorables cuando se utiliza como material de superficie de apoyo para implantes de cadera. Sin embargo, las partículas producidas por el desgaste del UHMWPE hacen que la vida útil de un THR sea un desafío clave. La pérdida ósea (osteólisis) producida por estas partículas de desgaste es una de las causas principales del fracaso total de la artroplastia articular. Además de mejorar la resistencia al desgaste de las superficies de apoyo, a fin de reducir dicho desgaste, también deben investigarse a fondo los mecanismos de distribución de los restos de las partículas desgastadas en las juntas de la prótesis. Estas partículas se distribuyen a través del lubricante en los huecos del implante. El líquido sinovial (SF), un líquido viscoelástico no newtoniano no adelgazante, lubrifica las articulaciones naturales. El comportamiento no-newtoniano de SF se atribuye a su contenido de ácido hialurónico (HA), que es un biopolímero lineal. Los patrones de distribución de estas partículas de desgaste se ven afectados por los comportamientos reológicos especiales de la SF, por parámetros geométricos, por tamaños y formas de partículas y por interacciones entre partículas y fluidos. Por lo tanto, la comprensión de este patrón de distribución es fundamental para minimizar el desgaste del tercer cuerpo del UHMWPE. Según las fuerzas mecánicas de los fluidos, el tamaño y la densidad de las partículas de desgaste sugiere que las partículas de desgaste siguen el movimiento del lubricante. Sin embargo, en cuestión de horas, estas partículas muestran comportamientos específicos dentro del fluido viscoelástico (no visible en el fluido newtoniano), tales como la migración de partículas y la formación de cordones a lo largo de la dirección del flujo. El objetivo principal de este proyecto fue desarrollar y validar un método experimental para evaluar las características de HA y soluciones artificiales SF y el comportamiento de las partículas de desgaste en un flujo de fluido viscoelástico. Se cuantificaron los efectos de diferentes parámetros, tales como la concentración de HA, el contenido de proteína, los tipos de flujo de fluido (constante, inestable, etc.) y las formas de los huecos en el comportamiento de los fluidos, a fin de poder comprender plenamente dichos mecanismos. La velocimetría de imagen de micropartículas (micro-PIV) se aplicó como el método de visualización cuantitativa del flujo en este proyecto. Se realizaron mediciones pin-on-disk como técnica complementaria, para investigar el comportamiento de fricción de una varilla de rotación de UHMWPE contra un disco de cobalto cromo molibdeno (CoCrMo) en presencia de soluciones HA de diversas concentraciones. Este estudio se llevó a cabo para comprender los efectos de la carga dinámica sobre el rendimiento del lubricante, en relación con los de carga estática. Los resultados muestran que bajo condiciones de flujo oscilatorio, los niveles de deformación, las tasas y las distribuciones son parámetros importantes que afectan los comportamientos de flujo de las soluciones de HA. La migración de partículas y la alineación se vieron afectadas por los tamaños de canales, las concentraciones de HA, los tipos de flujo y la inestabilidad elástica de la solución. Los resultados de la medición pin-on-disk sugieren que, en presencia de HA, la carga dinámica sinusoidal no afecta los comportamientos de fricción de UHMWPE con CoCrMo, en comparación con la carga estática.

Turbulence and sediment interactions have been studied widely over recent years, this work being mainly carried out in estuarine environments. Due to the development of instrumentation and processing techniques it is now possible to obtain good quality measurements of turbulence and sediment properties on the same temporal and spatial scales over reasonably long durations. Therefore, this study was designed to investigate the turbulence and sediment interactions over numerous tidal cycles at a shelf sea site. To this end the variation in suspended particulate matter (SPM) volume concentration, mass concentration and size, in conjunction with turbulent kinetic energy data, was investigated at a high energy tide-stirred site in the Irish Sea. The study site was located off the north-west coast of Anglesey and was notable for the presence of a turbid patch. Initial conclusions drawn from harmonic analysis, entropy analysis, and graphs of particle numbers indicated that possible sediment dynamics mechanisms controlling SPM magnitude and variation at the site were: resuspension, aggregation, disaggregation and advection of the turbid patch. It was found that the range of sediment sizes present at the site could be described by 2 characteristic sediment size populations: one fine (-50µm diameter) and one coarse (150µm). Two models were developed within the study to test these findings upon the 2 characteristic sediment size populations. The first, an advection model, which included no vertical mixing, was able to reproduce the underlying signal present within the observations (both in terms of magnitude and variability). This model was then incorporated into the second model which included turbulent vertical mixing, settling, erosion (resuspension) due to tidally generated shear stresses and turbulence controlled aggregation and disaggregation. 11 The full sediment dynamics model reproduced the variability and magnitude of the observations reasonably well. Small scale variability was also replicated by the model. Sensitivity analysis was then performed on the model to quantify the relative importance of each of the sediment dynamics processes at the study site. Results showed that for both size populations the 2 mechanisms controlling the magnitude of the SPM mass concentrations are erosion (resuspension) and aggregation/disaggregation, erosion being dominant for the coarse population and aggregation/disaggregation being dominant for the fine population. In terms of the variability, advection is by far the dominant mechanism for controlling the coarse population. Aggregation/disaggregation and advection control most of the variability in the fine population at this site.

Le frottement exerce par l'ecoulement sur un fond plat lisse est calcule a l'aide d'un modele de fermeture turbulente de type k-l en 1dv. Les resultats generalises sous une forme parametrique permettent de calculer rapidement les frottements maximum et moyen pour toutes les combinaisons d'un courant et d'une houle colineaires ou obliques. La distribution verticale et la variation temporelle de sediment en suspension sur un fond rugueux sont examinees par une autre version de ce meme modele. Les comparaisons intensives avec les experiences montrent les limites et les applications possibles de ce type de modele dans le genie cotier. La couche limite oscillatoire sur les fonds de rides est etudiee a l'aide d'une version 2dv du modele k-l et d'un modele de type vortex discret. La generation, le developpement et l'ejection des vortex autour des rides sont clairement reproduits par les modeles

Degradation of water resources has become one of the most pressing global concerns currently facing mankind. Constructed Wetlands (CWs) represent a concept to combat deterioration of water resources by acting as buffers between wastewater and receiving water bodies. Still, constructing wetlands for the sole purpose of wastewater treatment is a challenging task. To contribute to this research area, the fundamental question raised in this doctorate thesis was: how do factors such as vegetation and residing water movements (hydraulics) influence wastewater treatment in CWs? Also, effects of different data analysis methods for results of CW hydraulics and wastewater treatment were investigated. Research was focused on  phosphorus (P), ammonium-nitrogen (NH4+-N) and solids (TSS) in wastewater and o n P in macrophyte biomass. Studies were performed in pilot-scale free water surface (FWS) CW systems in Kenya (Chemelil) and Sweden (Halmstad) and as computer simulations. Results from the Chemelil CWs demonstrated that meeting effluent concentration standards simultaneously for all water quality parameters in one CW was difficult. Vegetation harvest, and thus nutrient uptake by young growing macrophytes, was important for maintaining low effluents of NH4+-N and P, especially during dry seasons. On the other hand, mature and dense vegetation growing for at least 4 months secured meeting TSS standards. Phosphorus in above-ground green biomass accounted for almost 1/3 of the total P mass removal, demonstrating high potential for P removal through macrophyte harvest in CWs. Also, results suggested that harvest should be species-specific to achieve high P removal by macrophytes and overall acceptable wastewater treatment in CWs. Still, different methods to estimate evapotranspiration (ET) from the Chemelil CWs showed that water balance calculations greatly impacted estimations of wastewater treatment results. Hydraulic tracer studies performed in the Chemelil and Halmstad CWs showed that mature and dense emergent vegetation in CWs could reduce effective treatment volumes (e-values), which emphasized the importance of regulating this type of vegetation. Also, it was shown that hydraulic tracer studies with lithium chloride performed in CWs with dense emergent vegetation had problems with low tracer recoveries. This problem could be reduced by promoting the distribution of incoming tracer solution into the CW using a barrier near the CW inlet pipe. Computer simulation results showed that the choice of tracer data analysis method greatly influenced quantifications of CW hydraulics and pollutant removal. The e-value could be 50% higher and the pollutant removal 13% higher depending upon used method. Moreover, unrealistic evalues (above 100%) in published literature could to some extent be explained by tracer data analysis method. Hence, to obtain more reliable hydraulic data and wastewater treatment results from CWs, more attention should be paid to the choice of tracer data analysis method.
Konstruerade våtmarker representerar ett koncept för möjligheten att nå en hållbar vattenresurshantering genom att agera som ”filter” mellan föroreningskälla och viktiga vattenresurser såsom sjöar och hav. Mycket kunskap saknas däremot om hur man konstruerar våtmarker med en optimal och pålitlig vattenreningskapacitet. Den här avhandlingen undersöker därför hur vegetation och vattnets väg genom våtmarken (hydrauliken) påverkar avloppsvattenrening i våtmarker. Dessutom undersöktes hur valet av dataanalysmetod av insamlad data påverkar resultaten. Studier genomfördes i Kenya och Sverige i experimentvåtmarker (ca. 40-60 m2) och inkluderadedatainsamling av vattenkvalité, hydraulik (spårämnesexperiment) samt biomassa och fosfor i biomassan av två olika våtmarksväxter. Dessutom genomfördes datorsimuleringar. Resultaten från Kenya visade att växtskörd och efterföljande näringsupptag av nyskördade växter var viktig för att uppnå låga utgående koncentrationer av fosfor och ammonium i en tropisk våtmark, speciellt under torrsäsongen. Däremot var en välutvecklad och tät vegetation viktig för reningen av partiklar. Fosfor i grön växtbiomassa representerade cirka 1/3 av våtmarkernas totala fosforrening, vilket påvisade potentialen i att genom skörd ta bort fosfor från avloppsvatten m.h.a. konstruerade våtmarker. Resultaten pekade också på att skörden bör vara art-specifik för att uppnå en hög fosforrening och generellt bra vattenreningsresultat. Dock visade olika beräkningsmetoder att vattenbalansen i en tropisk våtmark markant kan påverka vattenreningsresultaten. Resultaten från spårämnesexperimenten demonstrerade att den effektiva våtmarksvolymen för vattenrening blev mindre vid hög täthet av övervattensväxter. Detta pekade på att regelbunden växtskörd var viktig för att uppnå god vattenrening i våtmarker. Experiment med spårämnet litium visade att man kan få felaktiga resultat p.g.a. att en del spårämne fasthålls på botten i våtmarken om denna har mycket övervattensväxter. Därför bör spridningen av spårämnet i sådana våtmarker underlättas m.h.a. en spridningsbarriär nära inloppsröret. Simuleringar visade också att valet av dataanalysmetod av spårämnesdata starkt kan påverka resultaten och därmed också vår tolkning av en våtmarks hydraulik och reningskapacitet. Den effektiva volymen kunde vara 50% högre och reningseffekten 13% högre beroende på vilken metod som användes. Likaså kan valet av dataanalysmetod ha bidragit till överskattade och orealistiska effektiva volymer (över 100%) i artiklar publicerade de senaste 25 åren. Genom att fokusera mer på valet av dataanalysmetod och t.ex. jämföra resultaten från två olika metoder kan man minimera risken för bristfälliga resultat och därmed felaktiga slutsatser om en våtmarks vattenreningskapacitet.

Cette thèse est consacrée à l’étude expérimentale des propriétés magnéto-optiques intrinsèques des nanotubes de carbone mono-paroi par spectroscopie de photoluminescence résolue en temps.Un dispositif de microscopie optique confocale de grande ouverture numérique (NA = 0.95),incluant un cryostat magnétique, permet l’étude de nanotubes suspendus à l’échelle individuelle,à température cryogénique (jusqu’à 2 Kelvin) et sous champ magnétique (jusqu’à 7 Tesla). L’évolution des spectres et des déclins de photoluminescence avec le champ magnétique montre l’influence de l’effet Aharonov-Bohm sur les deux excitons singulets de plus basse énergie, c’est à-dire l’exciton fondamental qui est optiquement inactif (exciton noir) et un exciton d’énergie supérieure séparé de quelques milliélectronvolts qui est optiquement actif (exciton brillant). L’interprétation de ces résultats à partir d’un modèle d’équations de taux qui intègre le couplage Aharonov-Bohm entre ces deux excitons permet de déterminer séparément les durées de vie excitoniques et de fournir des informations quantitatives sur la relaxation de l’énergie depuis les niveaux supérieurs photo-excités. La relaxation de l’énergie suite à la photo-excitation de la transition S22 conduit à une efficacité de peuplement de l’état brillant quatre fois plus faible que celle de l’état noir, mais qui augmente significativement lorsque la relaxation se produit depuis les niveaux excitoniques KK’. D’autre part, le bon rapport signal à bruit obtenu dans les spectres de photoluminescence permet de révéler l’existence d’un couplage intrinsèque en champ nul entre l’exciton noir et l’exciton brillant ainsi que le maintien de la mobilité excitonique dans les nanotubes suspendus à la température de l’hélium liquide
This thesis is dedicated to the experimental study of the intrinsic magneto-optical properties of single-walled carbon nanotubes through time-resolved photoluminescence spectroscopy. Measurements are performed on suspended nanotubes samples at the single-object level using a home-built confocal optical microscope with a large numerical aperture (NA = 0.95) operating at cryogenic temperature (down to 2K) and high magnetic field (up to 7T). The evolution of the photoluminescence spectra and decay signals with increasing magnetic fields shows the influence of the Aharonov-Bohm effect on the two lowest-energy singlet excitons, namely the ground exciton which is optically inactive (dark exciton) and an exciton lying a few millielectron volts higher in energy which is optically active (bright exciton). A model of these results based on rate equations and including the Aharonov-Bohm coupling between these two excitons enables to determine separately the excitons lifetimes and to derive quantitative information on the energy relaxation from the photo-excited higher levels. The energy relaxation following the photo-excitation of the S22 transition leads to a bright state population efficiency four times lower than that of the dark state, but it significantly increases when energy relaxation occurs from the KK’ excitonic levels. Thanks to a good signal to noise ratio, the photoluminescence spectra also reveal the presence of an intrinsic zero-field coupling between the dark and the brightexcitons, as well as an excitonic mobility preserved at liquid helium temperature in suspended nanotubes

“Will my flight be cancelled?” “Will I win the eBay auction?” These consumption and product acquisition situations would trigger the experience of . . . suspense. Suspense is defined as the overall anticipatory arousal associated with the hope and/or fear felt by a consumer assessing the likelihood of occurrence of an important and imminent consumption or acquisition event. If one views a potential outcome as causing pleasure (an approach appraisal), hope will be felt, while if one views a potential outcome as causing pain (an avoidance appraisal), fear will be felt. Other variables expected to indirectly impact suspense are frequency of probability change, degree of probability change and anticipation time. The conceptual model in this dissertation also proposes that people have an attitude toward the anticipation period and identifies four resolution emotions, satisfaction, disappointment, relief, and anguish, which may occur once the outcome is known. Further, attitude toward anticipation period and the resolution emotions are expected to affect attitude toward overall experience. Three studies were conducted. The objective of Studies 1 and 2 was to develop scales yielding reliable scores of hope, fear, and suspense. Fifty words related to hope, fear, and suspense were generated. In Study 1, 553 participants rated the words on the evaluative and activity dimensions using 18 semantic differential scale items. O-technique factor analysis was used to analyze the data in Study 1. In Study 2, 354 participants read one of three suspenseful stories, then indicated their hope, fear, and suspense. Exploratory and confirmatory factor analyses were used in Study 2. Study 3 consisted of an experiment in which 241 participants read a suspenseful house-buying scenario, then indicated their hope, fear, and suspense. Structural equation modeling was used to analyze the data in Study 3. Results supported the conceptualization of suspense: both hope and fear had a positive effect on suspense. Additionally, approach appraisal had a positive effect on hope, and avoidance appraisal had a positive effect on fear. The moderating effect of frequency of probability change was not supported. However, frequency of probability change did have a positive effect on both hope and fear.

The thesis is focused on building and technological project of medical rescue station on the street Kamenice in Brno. The building and technological project includes technology report, study the implementation of major technological stages, coordination situation buildings with wider relationships roadways, object-oriented time and financial plan ,construction project site equipment, design of building machines and mechanisms, the timetable of the main building structure, balance resources, technological note for design of the outer building cladding, inspection and test plan for the exterior cladding of the building, environmental and safety risks, the draft contract for work and itemized budget.

Doctoral thesis called Vibrations of slender bridge structures deals with comparison of constructions’ responses at different load model of pedestrians. Specifically, in practice commonly used model, where there are the effects of pedestrians replaced by forces acting in a certain place on the bridge and other model, which takes into account the load of pedestrians moving along the deck. Calculations of responses are performed by finite element method in program ANSYS. To obtain extreme values of responses It is used parametric calculation using the program OptiSlang. At first responses on the simplified constructions are evaluated for load of two pedestrians, as well as the responses on real bridges for load of two pedestrians and four pairs of pedestrians. Responses are also evaluated in terms of pedestrian’s comfort during use structures and analyzed for what groups of pedestrians are criteria still met and for which it is necessary to consider about use of devices to reduce vibration. Possible applications and design process of the vibration dampers are shown on different configurations on the bridges.

Die term speurverhaal impliseer ’n spesifieke soort verhaal of genre, tradisioneel triviaalliteratuur of ontspanningslektuur, met spesifieke kodes en konvensies. Enige konvensies is egter aanpasbaar en die grense tussen hoë kuns en populêre kultuur is vloeibaar, sodat dit moontlik is dat daar wel ʼn vertakking of subgenre wat die literêre speurverhaal genoem kan word, kon ontwikkel het. Die doel van hierdie verhandeling is om die volgende navorsingsvrae te beantwoord: Is daar wel speurverhale wat as literêre speurverhale gekategoriseer kan word? Indien nie, waarom word die kodes van die speurverhaal as narratiewe strategie gekies vir sekere romans? Wat is die verskille en ooreenkomste tussen die tradisionele speurverhaal en die sogenaamde literêre speurverhaal? Die verskynsel word ondersoek word deur twee romans wat moontlik as literêre speurverhale geklassifiseer kan word, nl. Een vir Azazel (Leroux, 1984) en Die boek van toeval en toeverlaat (Winterbach, 2006), te vergelyk met twee tradisionele speurverhale, nl. Reuk van die dood (Mouton, 2008) en Plaasmoord (Brynard, 2009), aan die hand van sekere struktuurelemente, nl. spanningslyn, plot, intrige, karakterisering, verteller, vertellersperspektief, tyd, en ruimte. ENGLISH : The term detective story indicates a specific kind of story or genre, traditionally recreational and light reading, with specific codes and conventions. However, any set of conventions are pliable and the boundaries between recreational and high art are fluid and constantly shifting. It is therefore possible that a subgenre of the detective story that can be called the literary detective story could have developed. The goal of this dissertation is to answer the following research questions: Are there detective stories that can be categorised as literary detective stories? If not, why is the detective element chosen as a narrative strategy for some novels? What are the differences and similarities between the traditional detective story and the so called literary detective novel?
Dissertation (MA)--University of Pretoria, 2010.
Afrikaans
unrestricted

Cette thèse est une contribution à l’étude de la dynamique sédimentaire dans l’écosystème de la rade de Brest. Elle a pour objectif de décrire, par la simulation numérique et l’observation in situ, le mouvement des masses d’eau et de sédiments sous l’influence de la marée à l’échelle de la rade, et l’impact de la distribution spatiale actuelle des populations de crépidules sur le transport de sédiments en suspension et l’évolution des fonds. Un modèle bidimensionnel horizontal (2DH) est mis en œuvre à partir du code TELEMAC. Il intègre la variabilité spatiale du substrat, et rend compte de la présence physique (macro-rugosité, partition de la contrainte de cisaillement) et de l’activité biologique (filtration de l’eau chargée de particules en suspension, production de biodépôts) des crépidules. Les mesures de hauteur d’eau, de vitesse du courant, et de vitesse de frottement valident de façon satisfaisante les choix de paramétrisation du modèle hydrodynamique. Les mesures de concentration de matière en suspension en rade de Brest sont sporadiques, et leur analyse est compliquée. Le modèle sédimentaire constitue un outil de compréhension. Il informe de l’évolution temporelle de la contribution de différents types de sédiments et de leur origine aux concentrations locales de sédiments en suspension et déposés. Il permet de suivre le cheminement des sédiments principalement en suspension, de quantifier les échanges entre les sous-bassins de la rade et avec le fond. L’introduction sur le fond des colonies de crépidules, sous forme de chaînes assimilées à des cylindres, induit une diminution de la vitesse du courant à l’aplomb et dans leur sillage, compensée par une augmentation en périphérie, entraînant une modification globale des zones d’érosion et de dépôt de sédiments. Localement, les macro-rugosités ont un effet antagoniste selon leur répartition: des densités moyennes augmentent le frottement de peau et les remises en suspension, tandis que des densités élevées induisent un masquage des sédiments sur le fond duquel résulte une accrétion. Par comparaison à leur impact hydrodynamique, l’activité biologique des crépidules joue un rôle secondaire sur la dynamique sédimentaire
This thesis is a contribution to the study of sediment dynamic in the ecosystem of the bay of Brest. It aims at describing, by numerical simulations and field observations, the movement of water and sediments in the bay under tidal forcing, and the impact of the present spatial distribution of slipper limpets on suspended sediment transport and bed evolution. A two-dimensional horizontal (2DH) model is implemented based on the TELEMAC numerical system. It integrates the spatial variability of bed sediments, accounts for the physical presence (macro-roughness, form drag - skin friction partitioning) and biological activity (filtration of water carrying suspended particles, production of biodeposit) of slipper limpets. Measurements of water level, mean flow velocity, and friction velocity satisfactorily validate the choice of parameters in the hydrodynamic model. Measurements of suspended matter concentration in the bay of Brest are sporadic, and their analysis complicated. The sediment model stands as a tool for better understanding sedimentary processes. It informs the temporal evolution of the contribution of different types of sediment, and their origin, to local suspended and deposited sediment concentrations. It allows to follow the paths of sediment transport predominantly in suspension, and to quantify the exchanges of sediments between the sub-basins of the bay and with the bed. The introduction of slipper limpet colonies on the bed, in the form of chains assimilated as cylinders, induces decreasing flow velocity above and in their wake, compensated by increasing flow velocity on the outskirts, which globally modify the patterns of sediment erosion and deposition in the bay. Locally, the macro-roughness elements have an antagonist effect depending on their distribution: medium densities increase skin friction and erosion flux, whereas high densities shelter bed sediments from which results accretion. By comparison to their hydrodynamic impact, the biological activity plays a secondary role on sediment dynamic

L'étude des matières en suspension (MES) minérales est essentielle pour comprendre le fonctionnement des écosystèmes en Manche : les MES influencent la pénétration de la lumière dans la colonne d'eau, paramètre clé pour la production biologique, et sont susceptibles de transporter des polluants et nutriments. Lors de ce travail, la dynamique des MES minérales de surface en Manche est étudiée à l'aide de deux méthodes complémentaires : l'observation par satellite et la modélisation numérique tridimensionnelle. Dans un premier temps, les images satellite MODIS et MERIS, traitées par l'algorithme semi-analytique développé par l'IFREMER et représentant les MES non-algales de surface, sont analysées afin d'élaborer trois modèles statistiques permettant d'estimer la MES de surface en fonction de variables basiques telles que le coefficient de marée, la hauteur significative des vagues et la concentration moyenne en chlorophylle-a. Dans un deuxième temps, le modèle hydrosédimentaire multiclasse tridimensionnel ROMS (Regional Ocean Modeling System) est implémenté en Manche. Il prend en considération le forçage par la marée aux frontières ouvertes, la contrainte exercée par le vent à la surface de la mer, l'interaction houle-courant en couche limite de fond et l'hétérogénéité spatiale réaliste du lit sédimentaire. Les résultats du modèle statistique le plus sophistiqué sont également utilisés pour forcer la concentration en MES aux frontières ouvertes du domaine de calcul. Des tests de sensibilité sur les conditions limites montrent l'importance de considérer de manière réaliste les sédiments entrant en Manche par les frontières ouvertes lors de la modélisation numérique. L'influence de la biologie sur les MES minérales est testée en utilisant une formulation de la vitesse de chute et de la contrainte critique d'érosion variant saisonnièrement. Grâce à ces deux outils associés, les influences respectives de la marée, de la houle et de la biologie sur les MES minérales sont mises en avant et localisées en Manche. Le modèle numérique prédit que les MES de surface sont composées principalement de silts (>70%). Les silts en suspension en surface proviennent majoritairement du lit sédimentaire près des côtes en Manche orientale et des frontières ouvertes du domaine de calcul à l'ouest de la presqu'île du Cotentin et au large en Manche centrale et orientale. Les variations des MES de surface sont ensuite étudiées aux échelles des cycles de marée semi-diurnes, vive-eau/morte-eau et autour d'un épisode de houles. Enfin, l'évolution de la concentration de sédiments dans la zone de forte turbidité autour de l'île de Wight peut être analysée suivant les conditions hydrodynamiques afin d'évaluer les rôles respectifs des processus locaux d'érosion/dépot et d'advection dans la génération de ces turbidités remarquables.

碩士
國立臺灣海洋大學
電機工程學系
100
In this thesis, the production of infrared sensors using MEMS technology , we use the optical resonator structure to measure specific wavelengths of infrared, and construction of the absorbing layer and the reflective layer in the structure to increase the infrared absorption rate, the final suspended structure, and thermal radiation absorption in the IR sensor will not lead to signal decrease as the thermal conductor is too high, so we use this microbridge structure, which reduces the noise equivalent power and the thermal conduct to achieve the sensitive infrared sensor. In infrared sensor materials, consider the TCR value is the bigger the better to achieve greater signal, therefore, selection of 40% ruthenium oxide and 60% aluminum oxide target weight ratio, and deposit oxide thin films by RF magnetron sputtering deposition system on the Si3N4/Si substrates, temperature and pressure in the growth of the film has a great influence on the characteristics of the films, too low or too high is not easy to make a good film, so we have choose the temperature of 120°C、pressure conditions in 1.0×10-2 torr to grow the film, and measured at the room temperature (300 K) , the TCR value of approximately -1.9 % (K-1). In device characteristics, we have designed several of suspend structures and used the arc spray technique to alloy different materials as electrodes, in order to reduce the thermal conduct, and there to improve the components of yield (close to 90 percent from 10 percent), and the response time reduced to 50 ms (decreased about 50% time). In the measurement of components, we use the blackbody as the standard infrared radiation, to place infrared sensor in the vacuum chamber, to use the germanium plane mirror to filter out the light source other than the infrared, to use the germanium lens to focus 2.5-inch light source on the 0.13cm×0.13cm sensor chip, to place and move the mask before the light source. The final signal will follow the illuminated to convert the resistance variation with the read circuit, and display images on the computer through the USB. In this thesis, the primary measurement of 8×8 array infrared dynamic image is finished.

碩士
國立中央大學
環境工程研究所
99
Coagulation is one of the most important procedure in water / wastewater treatment. Removing suspended solids and colloidal substances from water and wastewater is the main procedure to achieve the purpose of water purification. The concentration of suspended solid of influent and effluent is to determine the effectiveness of chemical process. The current system using the standard methods can not offer the necessary information immediately and completely which can make control strategy of wastewater treatment. To improve information’s efficiency, this study developed an automatic water quality monitoring system with the optical spectrum analysis technique to measure water quality, which has immediate reaction, cost low construction, etc. In addition, it has the advantage of non-contacted and real-time. This study is mainly to utilizing optical image spectrum analysis technique to measure suspended solids. And the intensity of beam has been revised from surface to underwater by relationship between intensity and distance. The Optical measure results compare with experimental results of standard methods. At wavelength of the incident beam 650 nm, the average difference is 8.10 mg/L and the average percentage difference is 5.42 %. At wavelength of 532 nm and the average difference is 23.04 mg/L, the average percentage difference is 25.33 %. Besides, all of the percentage of average relative difference are below 5 % for duplicate analysis. Applying optical image spectrum analysis to develop an automatic real-time water quality monitoring system for suspended solids is steady and accurate. It can not only offer real-time information for wastewater treatment, but also improve the efficiency and effectiveness of wastewater treatment.

碩士
國立臺灣大學
環境工程學研究所
89
NPSM, a non-point source model, was used to simulate the Diyu chi basin located in Feitsui reservoir catchment and the requirement of information and suitability of parameters were investigated. Furthermore, continuous data on suspended solid loading is limited in Taiwan, therefore an optical device was developed to monitor the turbidity continuously and the information was used to estimate the concentration of suspended solid in the stream. By calibrating with data of 1997 and verifying with data of 1998, the prediction of the daily flow is good and that of the suspended load is reasonable. Capability of the new turbidity monitoring device which may be operated from 6.5 to 400 mg/L or better is verified and the device could be operated with independent power source for its low energy requirement.

碩士
國立臺灣大學
生物環境系統工程學研究所
95
In the management of reservoir, non-point source pollutions caused by surface soil erosion are frequently encountered. In order to prevent this kind of problems, it is necessary to continually monitor the watershed of the reservoir as well as to real-time monitor the total suspended solid(TSS). The data of the water quality of Xin-Shan reservoir, Feitsui reservoir, Shimen reservoir, Baoshan reservoir, Yonghe-Shan reservoir, and Mingd reservoir used in the study were provided by Environmental Protection Administration of the Executive Yuan, R.O.C.. These data included electrical conductivity, dissolved oxygen, pH value, turbidity, temperature, month, chlorophyll-α, total phosphorus, total hardness, and transmissivity, in the period from 1993 to 2005. Suitable water quality parameters and observation stations were further chosen from the statistical results by cluster analysis of the water quality, dominance analysis of the observation stations, and correlation coefficient of the reservoirs. Back propagation artificial neural network was applied to real time analysis and prediction of the total suspended solids. However the estimation accuracy would vary with locations and soil types. From the results, it was also found that the nural network model may be used to estimate the concentration of suspended solids, which is difficult to be real time measured, by using several parameters of water quality, which are easier to be measured, under some specific conditions. When back propagation network was modified to predict the real time total suspended solids in Shimen reservoir, the results showed that the predicted variation tendency of total suspended solids in network output agrees well with that in expected output, the R2 can reach 0.63, the regression coefficient can reach 0.90. It could be concluded that the method of back propagation artificial neural network and water quality can be used to rapidly and accurately estimate TSS.

碩士
國立中山大學
海下科技暨應用海洋物理研究所
102
The suspended particles always play an important role as a carrier of organic carbon and heavy metals in the nearshore area and around the river mouth. Therefore, to understand how the carriers control the fate of these carried substances, we need to understand the variation of suspended particle characteristics. According to previous studies, the nature of suspended particle properties would be influenced by three factors, which are water-particle interaction, boundary layer effect, and biotransformation. The feature of these factors also would be changed by the river plume, under different hydrodynamic conditions. The physical process would affect the particle characteristics directly or indirectly, making the physical and biogeochemical process more complex. Consequently, we heired R/V Ocean Researcher III and conducted a field experiment from July 6 to July 9, 2012 to focus on the temporal variations of the suspended sediment characteristics and fators that influence them at a fixed location off the Zhuoshui River mouth, Taiwan. The CTD rosette was deployed with a laser in-situ scattering and transmissometry (LISST) to record the hydrographic profile (salinity, temperature, fluorescence, and volume concentration of suspended particle) and near-surface water samples (taken at 3 m depth). These samples were filtered onboard by Catnet (a nested filtration system) to separate the particle into four different grain-size classes. In addition, a floating platform was tethered to the research vessel on which a downward-looking ADCP (AQUAdopp, 1200 kHz) was mounted for measuring the current velocity during this experiment. The results indicated the tidally modulated fluctuation of the river plume off the mouth of the Zhuoshui River is the most important factor controlling the water column stability and characteristics of the suspended sediment. In the ambient seawater condition, the surface particle consisted of the fine-grained size-classes (< 10 μm、10 ~ 63 μm). The SSC value was about 10 mg/l, and sometimes increased via the resuspension process by the tidal current. In the river plume regime, the SSC value could reach 40 mg/l ~ 60 mg/l, and the surface particles presented a status of fluffyness which means heavily large volume but less weight and that was consisted of bio-particle and flocs. In addition, the flocs were likely broken due to the turbulence in the convergent zone of the river-plume front whose water column was unstable, and resulting in particles of high bulk density values.The EOF (Emperical Orthogonal Function) results showed the river plume affect the hydrographic condition and suspended particle characteristics within three different physical processes. The time series result of settling velocity of different size classes was calculated according to the Stokes Law, and they showed the value of > 153 μm class was larger than 0.314 mm/s, and the values of 153 ~ 63, 63 ~ 10, and < 10 μm classes were smaller than 12.001, 1.139, and 0.138 mm/s respectively. The average particle settling velocity is 0.54 ~ 30.93 mm/s

Bedrock islands add variation to the estuarine system that results in deviations from typical unconfined estuarine sediment transport patterns. Limited literature exists regarding the dynamics of seabed morphology, delta formation, sediment divergence patterns, and sedimentary facies classifications of non-fjordic bedrock confined systems. Such knowledge is critical to address coastal management concerns adequately. This research presents insights from the Skeena Estuary, a macrotidal estuary in northwestern Canada with a high fluvial sediment input (21.2-25.5 Mtyr-1). Descriptions on sub-environments, stratification, and sediment accumulation within the Skeena Estuary utilize HydroTrend model outputs of riverine sediment and discharge, Natural Resources Canada radiocarbon-dated sediment cores and grain size samples, and acoustic Doppler current profiler and conductivity-temperature-depth measurements from three field campaigns. Research findings delineate a fragmented delta structure with elongated mudflats and select areas of slope instability. Variations from well-mixed water circulation to lateral stratification, govern the slack tide flow transition and sediment transport pathways within seaward and landward passages of the estuary. Fostering a comprehensive understanding of bedrock confined estuary and delta systems has implications for the assessment of coastal management strategies, the productivity of ecological habitats, and the impacts of climate change within coastal areas.
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