La production sonore biologique, étudiée par acoustique passive, doit être évaluée comme méthode complémentaire pour l’étude des effets des perturbations anthropiques sur les milieux côtiers.Alors que les sons émis par les mammifères marins et les poissons sont largement documentés, ceux issus des invertébrés benthiques restent peu décrits, même si ces derniers peuvent assurer des fonctions-clés dans les systèmes marins. L’enjeu principal de cette thèse était d’évaluer la pertinence de l’utilisation de l’acoustique passive comme outil écologique en s’appuyant sur la biophonie des invertébrés benthiques d’habitats côtiers tempérés et plus particulièrement en prenant comme habitat-modèle les bancs de maërl de la rade de Brest. Nous avons mis en évidence l’existence d’espèces sonifères remarquables qui constituent de bons candidats pour leur suivi en milieu naturel. Ces travaux ont de plus montré l’importante contribution de certains invertébrés benthiques dans le paysage sonore sous-marin, encourageant à ne plus imputer systématiquement les sons benthiques uniquement aux « crevettes claqueuses ». Le deuxième volet de cette thèse a montré que les variations de production sonore des invertébrés benthiques, à l’échelle individuelle ou collective, offrent des informations précieuses sur la mise en évidence de stress tels qu’un bloom d’algues toxiques ou l’impact du dragage. Ainsi, le nombre de mouvements sonifères des coquilles Saint-Jacques est doublé en présence de fortes concentrations d’algues toxiques, et le paysage sonore des bancs de maërl fortement pêchés est trois fois plus silencieux et moins complexe que celui du maërl préservé. Les résultats de ce travail de thèse, discutés dans un contexte de développement d’outils pour l’évaluation de l’état de santé des écosystèmes marins, permettent l’émergence de nouvelles hypothèses de travail en écologie marine. / Biological sound production, as studied by passive acoustics, should be considered as a complementary method to study the effect of anthropogenic disturbances on coastal systems. While sounds emitted by marine mammals and fish are well documented, those from benthic invertebrates are poorly described, although they can play key roles in marine ecosystems. The main goal of this PhD work was to evaluate the suitability of passive acoustics as an ecological tool based on sound production by benthic invertebrates living in temperate coastal habitats, and particularly in maerl beds of the Bay of Brest.We highlighted the existence of interesting soniferous species that appear to be good candidates to monitor in the field. This work also showed the important contribution of some benthic invertebrates to the underwater soundscape, suggesting that benthic sounds should not be attributed only to snapping shrimps. The second part of this PhD thesis emphasized that changes in benthic invertebrate sound production, at individual or collective scales, provides valuable information on the detection of stress such as a toxic algal blooms or the impact of dredging. Thus, the number of soniferous movements made by the great scallop doubles in the presence of high concentrations of toxic algae, and the soundscape of heavily fished maerl beds is three times quieter and less complex than preserved ones. The results of this PhD thesis, which are discussed in the context of tool development for the assessment of marine ecosystem health, raise new working hypotheses in marine ecology.

Non-thermal plasma generated in a dielectric barrier packed-bed reactor has been used for the remediation of chlorinated volatile organic compounds. Chlorinated VOCs are important air pollutant gases which affect both the environment and human health. This thesis uses non-thermal plasma generated in single and multiple packed-bed plasma reactors for the decomposition of dichloromethane (CH2Cl2, DCM) and methyl chloride (CH3Cl). The overall aim of this thesis is to optimize the removal efficiency of DCM and CH3Cl in air plasma by investigating the influence of key process parameters. This thesis starts by investigating the influence of process parameters such as oxygen concentration, initial VOC concentration, energy density, and plasma residence time and background gas on the removal efficiency of both DCM and CH3Cl. Results of these investigations showed maximum removal efficiency with the addition of 2 to 4 % oxygen to nitrogen plasma. Oxygen concentrations in excess of 4 % decreased the decomposition of chlorinated VOCs as a result of ozone and NOx formation. This was improved by adding an alkene, propylene (C3H6), to the gas stream. With propylene additives, the maximum remediation of DCM was achieved in air plasma. It is thought that adding propylene resulted in the generation of more active radicals that play an important role in the decomposition process of DCM as well as a further oxidation of NO to NO2. Results in the single bed also showed that increasing the residence time increased the removal efficiency of chlorinated VOCs in plasma. This was optimized by designing a multiple packed-bed reactor consisting of three packed-bed cells in series, giving a total residence time of 4.2 seconds in the plasma region of the reactor. This reactor was used for both the removal of DCM, and a mixture of DCM and C3H6 in a nitrogen-oxygen gas mixture. A maximum removal efficiency of about 85 % for DCM was achieved in air plasma with the use of three plasma cells and the addition of C3H6 to the gas stream. Nitrogen oxides are air pollutants which are formed as by-products during the decomposition of chlorinated VOCs in plasmas containing nitrogen and oxygen. Results illustrate that the addition of a mixture of DCM and C3H6 resulted in the formation of the lowest concentration of nitric oxide, whilst the total nitrogen oxides concentrations did not increase. A summary of the findings of this work is presented in chapter eight as well as further work. To conclude, the maximum removal efficiency of dichloromethane was achieved in air plasma with the addition of 1000 ppm of propylene and the use of three packed-bed plasma cells in series. The lowest concentration of nitric oxide was formed in this situation.

Orientador: Gastão Wagner de Sousa Campos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T12:41:14Z (GMT). No. of bitstreams: 1 Coelho_IvanBatista_D.pdf: 1453557 bytes, checksum: 07b76c3a79c299482d41aa0fc03d7a79 (MD5) Previous issue date: 2013 / Resumo: Este trabalho tem como objetivo a análise dos principais movimentos do parque hospitalar brasileiro a partir da estruturação do Sistema Único de Saúde e da regulamentação da Saúde Suplementar. Para isto foram utilizadas séries históricas de dados a respeito de leitos, número e porte dos hospitais e outras variáveis extraídas do Cadastro Nacional de Estabelecimentos de Saúde (CNES), da Assistência Médico Sanitária (MAS), da Agência Nacional de Saúde (ANS) e do Sistema de Informações Hospitalares do SUS (SIHSUS), além de revisões bibliográficas sobre o tema. Estas séries de dados, associadas a variáveis econômicas e políticas permitiram uma análise do quadro atual e o desenho de cenários futuros possíveis. O resultado evidencia uma queda acentuada dos leitos hospitalares disponíveis ao SUS, com crescimento do número de hospitais vinculados à Saúde Suplementar. A distribuição pelo País é heterogênea, com maior concentração de leitos no Sul e Sudeste e nas capitais em detrimento do interior. Quando se trata de equipamentos de maior complexidade (unidades de terapia intensiva, tomógrafos, ressonância nuclear, etc.), estas diferenças se acentuam. No que tange à qualidade e resolutividade, a maior parte dos equipamentos de maior complexidade existentes no País não se encontram disponíveis ao SUS. Considerando os movimentos e as políticas atuais em curso vem se configurando no País um quadro hospitalar bipolar: Baixas resolutividade e incorporação tecnológica nos hospitais ligados ao SUS e alto grau de incorporação de equipamentos nos hospitais ligados à Saúde Suplementar. / Abstract: This study aims to analyze the key achievements of the Brazilian hospital complex based on the National Health Care System implementation and the establishment of Private Health Insurance groups. For such, we used historical series of data on hospital beds, number and size of hospitals and other variables from the National Register of Health Facilities (CNES), the Medical Sanitary Service (MAS), the National Health Agency (ANS) and Hospital Information System (SUS SIHSUS), and literature reviews on the topic. These data sets, combined with economic and political variables allowed an analysis of the current situation and a design of possible future scenarios. The result shows a sharp decline in hospital beds available to SUS, with growth in the number of hospitals tied to Private Health Insurance setting. The distribution all over the country is heterogeneous, with the highest concentration of beds in the South and Southeast and in capitals over the interior. When it comes to more complex equipment (intensive care units, CT scanners, magnetic resonance, etc..), these differences are highlighted. Regarding the quality and problem solving capacity, most of the equipment of higher complexity existing in the country are not available to SUS. Considering the current political movements, it has been emerging in the country a bipolar hospital structure: Low problem solving capacity and incorporation of technology in hospitals connected to the SUS and high degree of incorporation of equipment in hospitals linked to Private Health Insurance. / Doutorado / Política, Planejamento e Gestão em Saúde / Doutor em Saude Coletiva

No description available.

För att motverka halka på vägar och skapa bättre framkomlighet och trafiksäkerhet för trafikanter under vintersäsonger, används halkskyddsmedel på vägarna. I dagsläget och sannolikt under en överskådlig framtid innebär det att man använder natriumkloridbaserade medel NaCl i form av vägsalt då NaCl är det mest effektiva samt kostnadseffektiva medlet för halkskydd. Trots att NaCl är det mest effektiva medlet mot halka kan vägsalt samtidigt orsaka vissa negativa effekter på miljön. Studier visar på att vägsaltet sprider sig i miljön genom flera olika transportmekanismer vilket gör vägsaltet till ett komplext problem. Vägsalt påverkar bland annat träden negativt, långvarig exponering för salt kan försvaga träden och leda till att träden dör. Klimatförändringar har potentialen att även i framtiden öka, om än kontraintuitivt, efterfrågan på vägsalt i städer med kallt vinterklimat. Därav behövs ett proaktivt tillvägagångssätt för att minska de negativa effekterna vägsaltet har på miljön och träden. Forskning visar på att det finns behov av mer kunskap samt kvalitativa studier gällande vägsalt och dess miljöeffekter. Hittills har det inte funnits någon probabilistisk metod för att bedöma miljörisken vägsalt utgör för gatuträden för att ge nödvändigt stöd till beslutsfattare. Riskbedömningar och riskhantering är viktiga medel i beslutstödjande arbeten. Syftet med denna studie har därav varit att utveckla, tillämpa och utvärdera modeller för övergripande miljöriskbedömningar av vägsalt som ett miljöförorenande ämne. För studien valdes två gator i Stockholms stad, Vasagatan samt Sockenvägen. Studien inleds med litteraturstudier som behandlar trädens roll i urbana miljöer, vägsaltets spridningsvägar, vägsaltets påverkan på träden och miljön samt olika saltmanagementmetoder. Baserade på data från litteraturstudien utfördes miljöriskbedömningar för träd-och vegetation, grundvatten samt jord i studieområdena. En riskbedömning utfördes för ett scenario där vägsalt inte används på vägarna och risken detta kan utgöra för människor. Vidare utvecklades och arbetades det fram olika åtgärdsförslag för studieområdena. Åtgärdsförslagen bedömdes och graderades i en bedömningsmatris. Sammantaget belyser studien vikten av att kontinuerligt samla in saltdata, skapa förståelse för vägsaltets spridningsvägar, utföra miljöriskanalyser på flera miljöområden gällande vägsalt, arbeta fram olika saltmanagementmetoder samt upprätta policyn för vägsalt i syfte att minimera vägsaltets skadliga effekter på träden och ekosystemen i Stockholms stad. / To prevent slippery roads and ensure better traffic safety for road-users during winter seasons, de-icing agents are used on the roads. Currently and probably for the foreseeable future this means using the sodium chloride-based agent NaCl in the form of road salt, which currently is the most effective and cost-effective de-icer. Despite benefits for road safety road salt can at the same time pose negative effects on the environment. Several studies describe how road salt spreads in the environment through several different transport mechanisms, which deems road salt a complex problem. Road salt affects, among other things trees negatively, prolonged exposure to salt weakens the trees and can lead to the death of the damaged trees. Climate change has the potential to even in the future, albeit counterintuitively, increase the demand for NaCl based road salt, during winter seasons in cities with continental climate, as road salt is a cost-effective agent. Hence, a proactive approach is needed to be able to reduce the negative effects road salt has on the environment and trees. Research shows there is a need for more knowledge and qualitative studies regarding road salt and its environmental effects and the effects on street trees. Until now there has been no probabilistic method to assess the environmental risks posed by road salt on street trees to provide the necessary support to decision makers. Environmental risk assessments and risk management are important tools in decision support. The aim of this study has therefore been to develop, apply and evaluate a model for an overall environmental risk assessment of road salt as a pollutant. For the study two streets were chosen in the city of Stockholm, Vasagatan and Sockenvägen. The study is introduced with literature studies on the roles of trees in urban environments, the dispersal paths of road salt, the impact of road salt on trees and the environment and road salt management methods. Based on data from the literature study an environmental risk assessment was carried out for trees and vegetation, ground water and soil in the study areas. A risk assessment was carried out for a scenario where road salt is not applied on the roads and the risk this may pose to human health. Furthermore, various suggestions for mitigation methods for the study areas were developed. The proposed mitigation measures were assessed and graded in an assessment matrix. The study highlights the importance of collecting road salt data continuously over several seasons, creating an understanding of road salt's dispersal paths, performing environmental risk assessments and analysis on several environmental areas regarding road salt. The study also highlights the need for developing different salt management methods and establishing policies aimed to reduce harmful effects of road salt on the trees and ecosystems in the city of Stockholm.

No description available.

Industrial Control Systems (ICS) are an integral part of modernsociety, not least when it comes to controlling and protecting criticalinfrastructure such as power grids and water supply. There is a need to testthese systems for vulnerabilities, but it is often difficult if not impossible to doso in operational real time systems since they have been shown to be sensitiveeven to disturbances caused by benign diagnostic tools. This thesis exploreshow ICS field devices can be simulated in order to fool potential antagonists,and how they can be used in virtualized ICS for cyber security research. 8different field devices were simulated using the honeypot daemon Honeyd,and a generally applicable simulation methodology was developed. It was alsoexplored how these simulations can be further developed in order to functionlike real field devices in virtualized environments. / Industriella informations- och styrsystem utgör en viktig delav vårt moderna samhälle, inte minst när det gäller kontroll och skydd avkritisk infrastruktur som elnät och vattenförsörjning. Det finns stora behov avatt säkerhetstesta dessa typer av system, vilket ofta är omöjligt iproduktionsmiljöer med realtidskrav som är erkänt känsliga för störningar, tilloch med från vanligt förekommande analysverktyg. Denna rapport presenterarhur vanliga komponenter i industriella informations- och styrsystem kansimuleras för att lura potentiella antagonister, och hur de kan användas ivirtualiserade styrsystem för cybersäkerhetsforskning. 8 olika komponentersimulerades med hjälp av Honeyd, och en generellt applicerbarsimuleringsmetodik utvecklades. Hur dessa simuleringar kan vidareutvecklasför att fungera som riktiga styrsystemskomponenter i virtualiserade miljöer harockså undersökts.

[ES] La investigación se centra en los hostels urbanos contemporáneos desde la perspectiva de la arquitectura situando el foco en su rasgo definitorio: la cama como único espacio privado en un alojamiento colectivo. Se parte de la hipótesis de considerar que a raíz de cambios recientes en los hábitos y en las demandas de sus usuarios, este mueble tiende a diseñarse con un formato análogo a una pequeña habitación. Concebir las camas como habitáculos permite comprender los hostels como una agrupación de piezas completas e independientes instaladas en espacios colectivos de mayor tamaño. El resultado es un paisaje interior compuesto de camas que pone de manifiesto la aproximación entre este mueble y la ciudad. En base a este argumento, la cama se contempla como pequeña construcción, que integra componentes que amplían sus posibilidades de uso y le independizan de su entorno, a la vez que como unidad habitacional de arquitecturas de mayor tamaño caracterizadas por la ausencia de dormitorios privados y por su carácter colectivo. El mobiliario y su disposición en el espacio aporta información sobre un momento cultural e ideológico concreto. En este sentido, una modificación sustancial de algún aspecto constituye un síntoma de un cambio de costumbres de quienes hacen uso de él, permitiendo comparar formas de vida de contextos dispares a partir de soluciones equiparables en sus muebles. El presente trabajo tiene el objetivo de profundizar en el papel que adquiere la cama en los hostels y explorar la forma de vida asociada a su formato. Para ello, por un lado, se toman los albergues juveniles de la ciudad de Barcelona como caso de estudio. Este análisis permite explicar el programa desde la mirada de un arquitecto y detectar las transformaciones que con el tiempo han tenido lugar en el diseño de sus camas y en sus organizaciones espaciales. Por otro lado, se lleva a cabo una selección y comparación de un conjunto de imágenes de camas de procedencia dispar con formatos equiparables a las del hostel. La recopilación evidencia la relación existente entre el uso y el diseño del mueble, las características del espacio en el que se dispone y la mentalidad de la sociedad a la que pertenece. La comparativa permite contemplar los diseños de otras épocas como vigentes a la vez que poner en valor la cama de los hostels al contrastarla conceptualmente con otros ejemplares paradigmáticos. Mientras que el análisis documenta un caso de estudio concreto, su comparación con otros modelos pretende comprenderlo. Ampliar la mirada sobre la forma de alojamiento estudiada lleva a reflexiones a las que no se habría llegado solo con la observación de los hostels. El discurso revela la arquitectura que comporta el mueble de la cama y traza asociaciones entre su diseño y aspectos relativos al espacio en el que se dispone y a los modos de vida predominantes del contexto al que pertenece. Se trata de una llamada de atención sobre un objeto extremadamente cotidiano para expresar la importancia de revisitarlo a día de hoy. / [CA] La investigació se centra en els hostels urbans contemporanis des de la perspectiva de l'arquitectura situant el focus en el seu tret definitori: el llit com a únic espai privat en un allotjament col·lectiu. Es parteix de la hipòtesi de considerar que arran de canvis recents en els hàbits i en les demandes dels usuaris, aquest moble tendeix a dissenyar-se amb un format anàleg a una petita habitació. Concebre els llits com a habitacles permet comprendre els hostels com una agrupació de peces completes i independents instal·lades en espais col·lectius més grans. El resultat és un paisatge interior compost de llits que posa de manifest l'aproximació entre aquest moble i la ciutat. En base a aquest argument, el llit es contempla com a petita construcció, que integra components que amplien les seves possibilitats d'ús i l'independitzen del seu entorn, alhora que com a unitat habitacional d'arquitectures més grans caracteritzades per l'absència de dormitoris privats i pel seu caràcter col·lectiu. El mobiliari i la seua disposició a l'espai aporta informació sobre un moment cultural i ideològic concret. En aquest sentit, una modificació substancial d'algun aspecte constitueix un símptoma d'un canvi de costums dels qui en fan ús, permetent comparar formes de vida de contextos dispars a partir de solucions equiparables als mobles. Aquest treball té l'objectiu d'aprofundir en el paper que adquireix el llit als hostels i explorar la forma de vida associada al seu format. Per això, per una banda, es prenen els albergs juvenils de la ciutat de Barcelona com a cas d`estudi. Aquesta anàlisi permet explicar el programa des de la mirada d'un arquitecte i detectar les transformacions que amb el temps han tingut lloc en el disseny dels llits i les organitzacions espacials. D'altra banda, es fa una selecció i comparació d'un conjunt d'imatges de llits de procedència dispar amb formats equiparables als del hostel. La recopilació evidència la relació existent entre l'ús i el disseny del moble, les característiques de l'espai on es disposa i la mentalitat de la societat a què pertany. La comparativa permet contemplar els dissenys d'altres èpoques com a vigents alhora que posar en valor el llit dels hostels en contrastar-lo conceptualment amb altres exemplars paradigmàtics. Mentre que l'anàlisi documenta un cas d'estudi concret, la comparació amb altres models pretén comprendre'l. Ampliar la mirada sobre la forma d'allotjament estudiada porta a reflexions a què no s'hauria arribat només amb l'observació dels hostels. El discurs revela l'arquitectura que comporta el moble del llit i traça associacions entre el disseny i els aspectes relatius a l'espai on es disposa i als modes de vida predominants del seu context. Es tracta d'una crida d'atenció sobre un objecte extremadament quotidià per expressar la importància de revisitar-lo avui dia. / [EN] The research focuses on contemporary urban hostels from an architectural perspective, placing the central point on their defining feature: the bed as the only private space in collective accommodation. It starts from the hypothesis of considering that this piece of furniture tends to be designed in a format analogous to a small room as a result of recent changes in the habits and demands of its users. Conceiving beds as rooms allows us to understand hostels as a group of complete and independent pieces installed in larger collective spaces. The result is an interior landscape composed of beds that reveals the relationship between this piece of furniture and the city. Based on this argument, the bed is considered as a small construction, which integrates components that expand its possibilities of use and make it independent from its surroundings, and at the same time as a living unit of larger architectures characterized by the absence of private bedrooms and by their collective nature. This furnishing and their arrangement in the space provide information about a specific cultural and ideological moment. In this sense, a substantial modification of some aspect is a symptom of a change in the habits of those who use it, making it possible to compare lifestyles from different contexts on the basis of comparable solutions in their furniture. The aim of this research is to study the role of the bed in hostels and to explore the way of life associated with their format. To do this, on the one hand, the youth hostels in the city of Barcelona are taken as a case study. This analysis explains their program from an architect's point of view and detects the transformations that have taken place over time in the design of its beds and in its spatial organizations. On the other hand, a selection and comparison of a set of images of beds of different origins with formats comparable to those of hostels is carried out. This collection evidences the relationship between the use and design of the furniture, the characteristics of the space in which it is arranged and the mentality of the society to which it belongs. The comparison allows us to consider the designs of other periods as valid while highlighting the value of hostels beds by conceptually contrasting them with other paradigmatic examples. Whereas the analysis documents a specific case study, its comparison with other models aims to understand it. Broadening the gaze on the form of accommodation studied leads to reflections that would not have been possible by observing the hostels alone. The discourse reveals the architecture of the bed furniture and draws associations between its design and aspects related to the space in which it is arranged and the predominant ways of life in its context. It is a call for attention to an extremely everyday object to express the importance of revisiting it today. / Tesis realizada gracias a la financiación del Ministerio de Educación y Formación Profesional a través de un contrato de formación de profesorado universitario (FPU-16/01717, octubre 2017-marzo 2022) y una ayuda para una estancia de investigación (marzo-mayo 2019). / Miguel Pastor, MD. (2023). De la cama a la ciudad. Aproximación al hostel urbano desde el ámbito privado. Barcelona como caso de estudio [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/196680

Cette thèse porte sur l'étude numérique des écoulements fluide-particules rencontrés dans l'industrie. Ces travaux se situent dans le cadre de la compréhension des phénomènes qui se déroulent dans des tambours tournants et réacteurs à lit fixe en présence de particules de forme non convexe. En effet, la forme des particules influence de manière importante la dynamique de ces milieux. A cet effet, nous nous sommes servis de la plateforme numérique parallèle Grans3D pour la dynamique des milieux granulaires et PeliGRIFF pour les écoulements multiphasiques. Dans la première partie de cette thèse, nous avons développé une nouvelle stratégie numérique qui permet de prendre en compte des particules de forme arbitrairement non convexe dans le solveur Grains3D. Elle consiste à décomposer une forme non convexe en plusieurs formes convexes quelconques. Nous avons nommé cette méthode « glued-convex ». Le modèle a été validé avec succès sur des résultats théoriques et expérimentaux de tambours tournants en présence de particules en forme de croix. Nous avons aussi utilisé le modèle pour simuler le chargement de réacteurs à lits fixes puis des lois de corrélation sur les taux de vide ont été déduites de nos résultats numériques. Dans ces travaux, nous avons aussi testé les performances parallèles de nos outils sur des simulations numériques à grande échelle de divers systèmes de particules convexes. La deuxième partie de cette thèse a été consacrée à l'extension du solveur PeliGRIFF à pouvoir prendre en compte la présence de particules multilobées (non convexes) dans des écoulements monophasiques. Une approche du type Simulation Numérique Directe, basée sur les Multiplicateurs de Lagrange Distribués / Domaine Fictif (DLM/FD), a alors été adoptée pour résoudre l'écoulement autour des particules. Une série d'études de convergence spatiale a été faite basée sur diverses configurations et divers régimes. Enfin, ces outils ont été utilisés pour simuler des écoulements au travers de lits fixes de particules de forme multi-lobée dans le but d'étudier l'influence de la forme des particules sur l'hydrodynamique dans ces lits. Les résultats ont montré une consistance avec les résultats expérimentaux disponibles dans la littérature. / Non convex granular media are involved in many industrial processes as, e.g., particle calcination/drying in rotating drums or solid catalyst particles in chemical reactors. In the case of optimizing the shape of catalysts, the experimental discrimination of new shapes based on packing density and pressure drop proved to be difficult due to the limited control of size distribution and loading procedure. There is therefore a strong interest in developing numerical tools to predict the dynamics of granular media made of particles of arbitrary shape and to simulate the flow of a fluid (either liquid or gas) around these particles. Non-convex particles are even more challenging than convex particles due to the potential multiplicity of contact points between two solid bodies. In this work, we implement new numerical strategies in our home made high-fidelity parallel numerical tools: Grains3D for granular dynamics of solid particles and PeliGRIFF for reactive fluid/solid flows. The first part of this work consists in extending the modelling capabilities of Grains3D from convex to non-convex particles based on the decomposition of a non-convex shape into a set of convex particles. We validate our numerical model with existing analytical solutions and experimental data on a rotating drum filled with 2D cross particle shapes. We also use Grains3D to study the loading of semi-periodic small size reactors with trilobic and quadralobic particles. The second part of this work consists in extending the modelling capabilities of PeliGRIFF to handle poly-lobed (and hence non-convex) particles. Our Particle Resolved Simulation (PRS) method is based on a Distributed Lagrange Multiplier / Fictitious Domain (DLM/FD) formulation combined with a Finite Volume / Staggered Grid (FV/SG) discretization scheme. Due to the lack of analytical solutions and experimental data, we assess the accuracy of our PRS method by examining the space convergence of the computed solution in assorted flow configurations such as the flow through a periodic array of poly-lobed particles and the flow in a small size packed bed reactor. Our simulation results are overall consistent with previous experimental work.

Use of geosynthetics for reinforcing soil beds supporting shallow foundations has gained tremendous popularity in recent times. In this thesis, to study and understand the behaviour of geosynthetics reinforced soil foundations, model load tests are carried out on square footings resting on sand beds reinforced with geosynthetics. The effects of various parameters like type and tensile strength of geosynthetic material, depth of reinforced zone, spacing of reinforcement layers, width of reinforcement and form of reinforcement on the performance of square footings on reinforced sand beds are studied. Results from these tests are analyzed to understand the effect of various parameters in improving the bearing capacity and reducing the settlement of footings. An equation is developed to estimate the ultimate bearing capacity of square footings resting on geosynthetic reinforced sand beds by multiple regression analysis of the experimental data. The model loading tests on reinforced soil foundations are simulated in the numerical model using the computer program FLAC3D (Fast Lagrangian Analysis of Continua in 3D). Finally parametric studies on a full scale reinforced soil foundation are conducted. From the experimental, analytical and numerical investigations carried out in this thesis, some important conclusions are drawn regarding the effective depth of reinforced zone, optimum spacing and quantity of reinforcement layers. Relative efficiency of various forms of reinforcement is discussed. Validity of the regression and numerical models developed is verified through experimental data from present study and also for data from other researchers.