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Au cours des 20 dernières années, l'utilisation de méthode de guidage par imagerie s'est progressivemen imposé comme gold standar dans nombre d'indications Interventionel antidouleur. Les modalités de guidage els plus utilisés sont la fluoroscopie et l'échographie. Le Scanner est relativement sous-utilisé dans le domaine de la prise en charge interventionnelle de la douleur, principalement en raison des difficultés d'accès et de Disponibilités pour les praticiens de la douleur. Au travers de cette thèse, nous avons montré l'intérêt du guidage scanner dans plusieurs indications avec de bons résultats, grâce à des techniques innovantes* L'Évaluation de l'alcoolisation percutanée du ganglion sphéno-palatin dans la prise en charge de ladouleur cranio-faciale réfractaire, chez 42 patients avec taux d'efficacité globale d'alcoolisation du GSP de67,2% et une durée moyenne de soulagement de la douleur de 10,3 mois. L'analyse a montré un tauxd'efficacité élevé chez les patients avec des algies vasculaires de la face (76,5%) et des syndromesdouloureux faciaux persistent (85,7%)* L' Évaluation de l'efficacité d'un méthode simplifiée d'infiltration sous scanner du nerf grandoccipital (NGO) chez 33 patients souffrant d'une névralgie occipitale avec taux de succès clinique de 86%.En cas de succès clinique, la durée moyenne de soulagement de la douleur suivant la procédure était de9,16 mois.*La comparaison deu block vs. neurolyse par radiofréqence du ganglion stellaire sous guidage scannographique dans la prise en charge du Syndrome Douloureux Régional Complexe de Type 1 du membre supérieur chez 67 patients: on retrouve une efficacité supérieure dans le groupe RFN (67,6%, 23/34) par rapport au groupe de block (21,2%, 7/33) avec un OR de 7,76.* L'Évaluation de la neurolysepar RF des nerfs ilio-inguinal et ilio hypogastrique chez les patients souffrant de douleurs ilio-inguinal et à l'aine réfractaire.• pouvait conduire à une amélioration des résultats. Dans tous les cas, le guidage par Scanner est une valeur ajoutée dans certaines indications, car elle permet en toute sécurité, le placement précis, millimétrique, de l'aiguille. Une autre solution possible afin de réduire les risques liés à certains gestes serait le développement d'une L'Étude préliminaire sur 16 patients traités par RFN a montré une réduction significative dela douleur après RFN pendant 11,8 mois.• Une deuxième étude a été menée permettant de comparer l'efficacité de la RFN et à cellede l'infiltration dans la même indication chez 42 patients: La durée moyenne de soulagementde la douleur était statistiquement supérieure (P = 0,005) dans le groupe RF (12,5 mois)comparé au groupe d'infiltration (1,6 mois).Au cours de ces études publiées, nous avons montré que l'application d'une technique existante (neurolyse, infiltration) à une nouvelle indication, ou la modification d'une technique existante après des considérations anatomiques sonde de radiofréquence unidirectionnel, capable de créer une zone d'ablation en demi sphère dont l'orientation serait contrôlable, ce qui permettrait de réduire les risques d'ablation non désirée.Enfin, il est important de rappeler, que la prise en charge interventionnelle de la douleur d'un patient s'intègre dans une prise en charge globale, centrée autour du patient. Ainsi, la prise en charge d'un patient douloureux ne pourra se faire de manière efficace qu'en prenant en compte l'ensemble des aspects de la douleur exprimé par le patient, bien au delà des seules considérations techniques d'un geste interventionnel. / Over the past 20 years, the use of imaging guidance has progressively but very rapidly evolved to become a standard practice to date, with fluoroscopy and Ultrasound being the most popular imaging guiding tools. However, CT guidance is relatively underused in the field of Interventional pain management, mainly due to acces and availabilty issues for pain physicians. Therefore, the objective of this thesis are mulitple :* to evaluate the usefulness of CT scan guidance, in applying existing neurolytic techniques(block.infiltration and neurolysis) to innovative indications, allowed by the use of such an imagingguiding tool.* to evaluate the clinical effectiveness of these novel indications* Finally, to emphasize on the importance of the clinical aspects of Interventional pain managementAfter after having reminded the definitions of the different existing techniques (neural blocks, infiltration, neurolysis) and detailed existing materials (Local anesthestics, Steroids, Chemical Neurolysis, Physical Neurolysis), a brief description of existing indication of Interventional Pain will be made. Emphasis will then be made on the assessment of innovative interventional CT Guided pain techniques in various refractory pain syndromes :- Evaluation of Alcohol percutaneous neurolysis of the sphenopalatine ganglion in the management of refractory cranio facial pain , in 42 patients : overall efficacy rate of alcohol SPN was 67.2% with a mean pain relief duration of 10,3 months. Analysis showed a higher efficacy rate in patients with Cluster Headaches (76.5%) andPersisting Facial Idiopathic Pain (85.7%)- Evaluation of the efficacy of a simplified CT guided greater occipital nerve (GON) infiltration approach inthe management of occipital neuralgia (ON) in 33 patients : Clinical success rate was 86%. In case of clinicalsuccess, mean pain relief duration following procedure was 9.16 months.- Evaluation of CT-guided Stellate Ganglion Blockade vs. Radiofrequency Neurolysis in the Managementof Refractory type I Complex Régional Pain Syndrome of the Upper Limb in 67 patients : analysis performed onthe blockade and RFN groups showed a significantly (P<0.0001) higher success rate in the RFN group (67.6%,23/34) compared with thé blockade group (21.2%, 7/33) with an OR of 7.76.- Evaluation of CT Guided ilio inguinal (II) and ilio hypogastric Radiofrequency Neurolysis (RFN) inpatients with refractory ilio-inguinal and groin pain.* Preliminary Study on 16 patients treated with II RFN showed significant pain reductionafter RFN with a mean pain relief of 11,8 months.* A second study was conducted to compared the effectiveness of RFN and Infiltration in thesame indication in 42 patients : Mean duration of pain relief was statistically significant (P = .005)in the RF group (12.5 months) compared to the infiltration group (1.6 months).Throughout these published studies, we hâve shown that the application of an existing neurolytic technique in a new indication, or modifying an existing technique after anatomical considerations may lead to either higher efficacy rates, longer pain reliefs, or safer procedures. In ail cases, CT guidance is an added value to any procédures as it allows safe, précise accurate and effective needle placement in most procedures. Another possible solution to reduce procedure related risks discussed in this thesis, is the development of a unidirectional radiofrequency probe, capable of producing tissue destruction only on one half on the probe thereby creating a half mooned shaped thermal zone, which would reduce the risk of surrounding unwanted tissue damage. This topic merits further studies and development as possible everyday implications are numerous .

Cette thèse a été effectuée dans le cadre du projet ANCRES. Son rôle est d'assurer la compréhension physique du milieu récepteur, le sol, alors qu'une autre équipe étudie l'impact physico-chimique des eaux usées traitées sur le sol. Pour cela, il faut connaître ses propriétés texturales et structurales contrôlant ses fonctions d'épuration et d'évacuation. La problématique est donc de comprendre le processus de l'infiltration imposée par un dispositif d'ANC dans un sol caillouteux. D'abord, suite au positionnement du site pilote d'ANC au pied d'un versant au cœur du plateau portlandien dans le département de l'Yonne en France, on a identifié là un type de sol hétérogène et complexe, caillouteux, une colluvion qui n'était pas cartographiée sur la carte géologique BRGM de cette région et sur laquelle on focalise la thèse. Ensuite, dans le sol complexe du site pilote, on a d'abord mesuré la conductivité hydraulique du sol par l'appareil Guelph sur 15 m² de la fouille de l'ANC à une profondeur de 120 cm : au total, on a fait 15 essais d'infiltration. De plus, on a récupéré 15 échantillons du sol accompagnant ses essais de Guelph pour la caractérisation physique au laboratoire. On a mesuré la texture, l'humidité résiduelle (HR), la teneur en cailloux (Rw) et la matière organique (MO) des échantillons au laboratoire. Ensuite, pour l'étude du processus d'infiltration, on a instrumenté ce site par un dispositif de surveillance hydrique (tensiométrie, teneur en eau, piézométrie) et de prélèvement d'eau interstitielle du sol. De plus, la masse volumique (densité) apparente d'un sol hétérogène a été déterminée. Parmi les paramètres mesurés, certains sont choisis comme indicateurs pour caractériser un sol comme milieu récepteur potentiel des eaux usées traitées en ANC. Puis, en utilisant la MO et la texture des échantillons, on a estimé la masse volumique apparente de la matrice du sol du site piloteau moyen de fonctions de pédotransfert appelées BD-FPTs et on a testé la relation entre la conductivité hydraulique à saturation Ks et la texture de ce sol complexe. Pour cela, une méthodologie en quatre phases a été développée pour évaluer la capacité prédictive des fonctions Ks-FPTs. Cette méthodologie de sélection n'a pas été trouvée dans la littérature mais est élaborée pour les besoins de la thèse. On a déduit les meilleures Ks-FPTs pour ce type de sol. Enfin, avec les données d'humidité volumique et du potentiel matriciel du sol, acquises par une centrale d'acquisition des données, le régime hydrodynamique du sol sous le massif filtrant de l'ANC a été étudié et on a mis en évidence l'écoulement préférentiel dans un sol caillouteux. Les résultats ont montré que dans la colluvion, bien que la matrice du sol soit fine, la conductivité hydraulique mesurée est plus élevée qu'attendu. Cela démontre que la fraction des cailloux dans le sol joue un rôle essentiel en accélérant l'évacuation des eaux usées traitées et aussi l'eau pluviale vers les couches sous-jacentes, et finalement vers la nappe. Cette propriété serait un point fort pour la fonction de transfert du sol et on peut en déduire une méthode pour améliorer la capacité de transfert de l'eau des sols lourds dans les projets d'aménagement urbain ou périurbain : l'ajout de graviers et graves calcaires par mélange au sol en place. On conclut que cette expérimentation, unique en son genre, a été utile pour évaluer la fonction de rétention / transfert de l'eau dans le sol recevant les eaux usées traitées. On a identifié les paramètres prédicteurs pertinents et les relations empiriques qui permettent de faire l'économie de nombreux essais in situ d'eau / The soil is an essential compartment in hydrologic cycle of water in the nature. Therefore, it is clear that taking into account the properties and organization of the soil is essential to the understanding and management of flows involved in the development of the quality of groundwater and surface water. The on-site sanitation (ANC) is a management method of domestic wastewater, by which the water is sent into the soil after settling and filtration liquefaction / aerobic degradation. The second step was often provided by the top soil in place himself, and this continues to this day on many plots of on-site sanitation.This thesis was carried out under ANCRES project. Its role was to ensure the physical understanding of the receptor medium, soil, while another research team was investigating the physico-chemical impact of treated wastewater on the sol. To ensure it, we have to understand its textural and structural properties controlling its purifying power and hydrodynamic processes. So, the problematic is to understand the process of infiltration imposed by an ANC in a heterogeneous stony soil. At first, due to the positioning of the pilot ANC site, at the foot of a slope in the Yonne department in France, a type of complex and heterogeneous soil, a colluvion, was identified. This soil has not been mapped on the BRGM (Bureau de recherches géologiques et minières) geological map of the area. So, the thesis was focalised on this soil. Then, in this soil complex at a depth of the 120 cm of the excavation of the ANC, the soil hydraulic conductivity was first measured by a Guelph apparatus on 15 m². We totally made 15 infiltration tests. Furthermore, we have collected 15 soil samples with each Guelph test for physics laboratory physical characterization. Then, in order to study the soil functions, this site was instrumented by the water monitoring devices (tensiometers, water content probes, and piezometer) and the interstitial water sampling device from the soil. In addition, the bulk of this heterogeneous soil was determined. Among the measured parameters, a series of indicators chosen to characterize the soil as a potential receptor medium of treated wastewater of the ANC. Then, the bulk density of the soil matrix using pedotransfer functions called BD-FPTs was estimated and the relationship between saturated hydraulic conductivity Ks and the texture of the soil complex (by Ks-FPT function) was tested. For this aim, a four-phase methodology was developed to assess the predictive ability of Ks- FPTs functions. This methodology in four phases is not found in the literature but was prepared for the purposes of the thesis. We concluded the best Ks- FPTS for this type of soil. Finally, with the volumetric water content and soil matrix potential data acquired by a the data loggers, the hydrodynamic regime of the soil under the sand pack of the ANC has been studied and demonstrated the preferential flow in a stony soil was demonstrated. The results showed that in the colluvion, although the soil matrix is fine, the measured hydraulic conductivity is higher than expected. This shows that the stone fraction in the soil plays an important role in accelerating the evacuation of treated wastewater and also rainwater to the underlying layers, and finally to the water table. This property would be a strong point for the transfer function of the soil and we can deduce a method to improve the transfer function of heavy soils in urban or peri-urban development projects. This could be possible by adding the gravel and -limestone to soil matrix and mixing them. It has been concluded that this experiment, unique in its kind, has been useful in evaluating the function of retention / transfer of water in the soil receiving treated wastewater. In addition, the relevant predictor parameters and empirical relationships that make the economy of many water tests were identified

Global forskning visar på att 60 procent av världens ekosystemtjänster i dagslget försämras, 2,6miljarder människor i världen saknar förbättrad sanitet, 2 miljarder människor är undernärda och 800miljoner människor saknar säkert dricksvatten. Allt detta är direkt har en direkt koppling tillvattensäkerhet.Sverige är ett av de länder med en av de mest långtgående standarderna för avloppsvatten i världen.Avloppsreningsverk infördes så tidigt som på 1930-talet. Det finns omkring 700 000 enskilda avlopp iSverige som är anslutna till en vattentoalett, men inte till något kommunalt reningsverk. Ungefär 26 %av dessa avloppsanläggningar använder endast någon slags slamavskiljning som behandlingsmetod,något som inte uppfyller lagkraven.Syftet med denna studie är få en grundlig bild av begreppet enskilt avlopp, och målet är att undersökavilka tekniker och vilken lagstiftning som finns gällande ämnet, för att likställa den informationen medtillståndsärenden från Östersunds kommun.Enskilda avlopp anses vara miljöfarliga verksamheter, av den orsaken att avloppsvatten kan bestå avsmittämnen, som virus och bakterier, och skadliga kemikalier. Därför måste man ansöka om tillstånd,eller anmäla enskilda avlopp till miljö- och samhällsnämnden på kommunen.I Sverige saknas bestämda lagar som reglerar enskilda avlopp. Däremot finns det flera regler somberör området. Lagen fastställer alltså inte några specifika krav gällande vilken teknik som skaanvändas för att rena avloppsvatten, eller hur bra reningen ska vara, utan snarare att det ska behandlaspå ett sådant sätt att det ger skydd till miljön och människors hälsa, och därtill även hushåller mednaturresurser. Hur hårda kraven är beror bland annat på hur känslig närmiljön är, samt antaletnärliggande avloppsanläggningar.Rapporten visar att den teknik som tycks vara den vanligast förekommande i Östersunds kommun ärinfiltration, utifrån det faktum att majoriteten av de valda tillståndsansökningarna i kommunen gällerden tekniken. / Global research shows that 60 percent of the world's ecosystem services are currently deteriorating,2.6 billion people in the world lack improved sanitation, 2 billion people are malnourished and 800million people lack safe drinking water. All of this is directly related to water safety.Sweden is one of the countries with one of the most far-reaching standards for wastewater in theworld. Sewage treatment plants were introduced as early as the 1930s. There are about 700,000individual sewers in Sweden that are connected to a water toilet, but not to a municipal treatmentplant. Approximately 26% of these sewage treatment plants use only some kind of sludge separationas a treatment method, something that does not meet the legal requirements.The purpose of this study is to get a thorough picture of the concept of individual sewers, and the goalis to investigate what techniques and what legislation exists regarding the subject, to equate thatinformation with permit applications from Östersund municipality.Individual sewages are considered to be an environmentally hazardous activity, for the reason thatwastewater can consist of infectious substances, such as viruses and bacteria, and harmful chemicals.Therefore, you must apply for a permit, or report individual sewers to the environment and communitycommittee at the municipality.In Sweden, there are no specific laws that regulate individual sewers. However, there are several rulesthat affect the area. The law thus does not lay down any specific requirements regarding whattechnology should be used to purify wastewater, or how good the treatment should be, but rather that itshould be treated in such a way that it provides protection for the environment and human health, andin addition also housekeepers natural resources. How strict the requirements are depends, among otherthings, on how sensitive the local environment is, as well as the number of nearby sewage plants.The report shows that the technology that seems to be the most common in Östersund municipality isinfiltration, based on the fact that all of the majority of the applications in the municipality apply tothat technology. / <p>2021-06-04</p>

In der vorliegenden Arbeit wurden Doppelringinfiltrationsexperimente an teilweise gefro­renen Böden durchgeführt. Diese Experimente wurden anschließend mit den zwei computer­ge­stützten Modellen, Erosion 3D / Winter und COUP, nachgestellt, um die Frage zu beantworten, ob es möglich ist, die Infiltration in teilweise gefrorene Böden vorherzusagen. Die Doppelringinfiltrationsexperimente wurden auf einem ackerbaulich genutzten Lehm­boden mit geringer Lagerungsdichte und Bodenfeuchten im Bereich der Feld­kapa­zität, an der nördlichen Grenze des hydrologischen Untersuchungsgebietes „Schäfertal“ durch­ge­führt. Drei Experimente erfolgten bei teilweise gefrorenen und ein Experiment bei unge­frorenem Boden. Bei diesen Experimenten wurde herausgefunden, dass die Endinfiltrationsrate des gefro­renen Bodens mit 7·10-5 m/s gleich der Endinfiltrationsrate des ungefrorenen Bodens war. Während bei dem Infiltrationsexperiment mit ungefrorenem Boden die Endinfiltrations­rate bereits nach 10 bis 20 min erreicht war, wurden bei den Experimenten mit gefrorenen Böden aufgrund der zusätzlichen Sättigung des kryoturbativen Sekundärporenvolumens mehr Zeit benötigt. Zu den im Boden ablaufenden Prozessen bei Zugabe von Infiltrationswasser (Tem­pe­ratur­veränderung, Gefrier- und Auftauprozesse, Veränderung der Porosität) besteht noch Klärungsbedarf. Der für die Modellierung wichtige Eingabeparameter der Anfangsbodenfeuchte konnte bei winterlichen Bedingungen nicht genau bestimmt werden. Gravimetrische Boden­feuchtebestimmungen liefern aufgrund des Eintrags von zusätzlichen Eis- und Schnee-Wasser zu hohe Werte. TDR- und Watermark-Messungen unterschätzen hingegen die Bodenfeuchten, weil sie nur den Anteil des flüssigen Wassers berücksichtigen. Mit Erosion 3D / Winter konnten die Ergebnisse der Infiltrationsexperimente, unter der Voraussetzung, dass die effektive gesättigte hydraulische Leitfähigkeit des ungefrorenen Bodens exakt bekannt war, sehr gut nachgestellt werden. Eine Modellierung der Infiltration in einen teilweise gefrorenen Boden ist damit, zumindest für den untersuchten Boden und die betrachteten meteorologischen Bedingungen, möglich. Das COUP - Modell lieferte dagegen völlig andere Ergebnisse, weil von einem Ein­frieren des infiltrierten Wassers bei negativen Temperaturen ausgegangen wird. Eine Verbesserung der Infiltrationsbeschreibungen könnte hier wahrscheinlich durch die Vorgabe einer größeren Anzahl von Eingabeparametern, die die natürliche Situation besser repräsentieren als die für die Modellierung verwendeten Daten, erfolgen.

Ephemeral streams with spatially and temporally variable flow are important ecological settings in semi-arid desert environments that until now have been poorly characterized. Our quantitative analysis explores how intermittent stream hydrology varies across geomorphic (mountain streams to desert washes) and climatic gradients (150-400 mm precipitation) in Southern Arizona. Stream channels were instrumented for the first time with a co-deployment of vertical profiles of subsurface temperature sensors, and electrical resistance (ER) sensors on the bed surface. HYDRUS 1-D was used to simulate vertical unsaturated flow, and differences along hydrologic, topographic, and climatic gradients were compared. Annual surface water presence varied < 1%-82% of the year, and reach-normalized infiltration water volumes were 20,000-2,500,000 m³/(km y). Surface water presence was correlated with geomorphic gradient, and infiltration volumes were correlated with surface water presence. This sensor co-deployment method has shown that ER sensors alone are necessary to estimate infiltration in semi-arid, poorly-sorted, coarse desert channels.

Electrospinning is a technique used to generate scaffolds composed of nano- to micron-sized fibers for use in tissue engineering. This technology possesses several key weaknesses that prevent it from adoption into the clinical treatment regime. One major weakness is the lack of porosity exhibited in most electrospun scaffolds, preventing cellular infiltration and thus hosts tissue integration. Another weakness seen in the field is the inability to physically cut electrospun scaffolds in the frontal plane for subsequent microscopic analysis (current electrospun scaffold analysis is limited to sectioning in the cross-sectional plane). Given this it becomes extremely difficult to associate spatial scaffold dynamics with a specific cellular response. In an effort to address these issues the research presented here will discuss modifications to electrospinning technology, cryosectioning technology, and our understanding of cellular infiltration mechanisms into electrospun scaffolds. Of note, the hypothesis of a potentially significant passive phase of cellular infiltration will be discussed as well as modifications to cell culture protocols aimed at establishing multiple passive infiltration phases during prolonged culture to encourage deep cellular infiltration.

Master of Science / Department of Civil Engineering / David G. Chandler / Infiltration capacity influences the ability of a soil to absorb and transmit water through macropores and micropores of the soil structure. Infiltration is primarily influenced by the soil type, which is dependent on a number of factors including parent material, climate, biological activity, and topography. Spatial controls of land use, land cover, soil texture, slope position, slope gradient and slope aspect are a few of the variables influencing infiltration capacity within a uniform soil type. The goals of the thesis are to (1) quantify the spatial distribution of soil hydraulic properties at the surface of a hillslope using one measurement method - the automated mini-disk tension infiltrometer - and several analysis methods, (2) determine the dependence of depth on soil hydraulic properties using two measurement methods, and (3) compare the results of the investigation with information from the soil survey and soil investigations. First, automated mini-disk infiltrometers were used to determine soil hydraulic properties at ten sites along a hillslope in Konza Prairie Natural Research Area. Several analysis methods were used to extract hydraulic conductivity and sorptivity values from the infiltration data. Next, large intact soil cores were extracted from three selected sites at the same hillslope and analyzed at six depths using a large disk infiltrometer. Finally, the six segments of the large soil cores were analyzed using the same methods as the field measurements with the mini-disk infiltrometers. The results of the field investigation at the ten sites show a variability of soil hydraulic properties over an assumed homogeneous landscape. The values of hydraulic conductivity and sorptivity are dependent on the method of analysis. An empirically based approach produced more realistic values than a physically based approach. The results of the laboratory investigation of the three extracted soil cores also show a dependence of method of analysis and measurement. In addition, the results show a complex relationship among landscape position, depth, and soil structure. Finally, while soil surveys and soil descriptions can provide detailed information on soil properties, an infiltration investigation at a detailed spatial scale provides quantitative values for soil hydraulic properties.

The goal of this PhD thesis was to develop dense aluminium compound-cubic boron nitride composites with a high cBN content. To achieve this goal, two different strategies were used: infiltration of cBN preforms and hot pressing of cBN-Al mixtures. The particle size of the cBN and the amount of aluminium were systematically varied and the influence of these parameters on densification and selected properties was evaluated. A basic understanding of the product that was formed over certain temperatures and times provides information that can be used in optimizing the infiltration and hot pressing of cBN with Al. For this reason, the reaction kinetics between Al and cBN was initially investigated. The reaction kinetics of the chemical interactions between Al and cBN was investigated in detail using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The reaction was studied using samples containing 50 volume percent of Al and 50 volume percent of cBN (12 μm) hot pressed at 800 oC. The prepared samples were allowed to react isothermally at temperatures between 1 000 oC and 1 400 oC under nitrogen (N2) and argon (Ar) atmospheres. It was found that the degree and rate of the reactions increased with increasing temperature in both N2 and Ar atmospheres. The degree of aluminium nitride (AlN) formation was considerably higher under N2 than under Ar. The difference in the formation of AlN between the two atmospheres was attributed to the reaction of N2 gas with the sample due to the open porosity. The infiltration of partially hexagonalized cBN matrix with molten Al was studied. The samples were found to have a density higher than 97% of the theoretical density. It was found that the amount of soft hBN phase present in the sample (due to hexagonalization) increases at temperatures higher than 1 300 oC, resulting in a hardness of the final material of Hv10 = 6.5 ± 4.8 GPa. Because of thie poor hardness this route was abandoned. Cubic boron nitride powder (12 μm) without hexagonal boron nitride (hBN) was also infiltrated with aluminium. The infiltrated samples were found to exhibit a density higher than 96% of the theoretical density. The Al reacted with cBN and no hBN was observed at temperatures below 1 400 oC. The resulting product showed a Vickers hardness of Hv10 = 14.4 ± 1.6 GPa compared with Hv10 = 6.5 ± 4.8 GPa obtained with the partially hexagonalized cBN matrix. Infiltration of 3 μm cubic boron nitride increased the Vickers hardness to 22.0 ± 0.6 GPa. However, this infiltration was not very reproducible. Al-cBN cermets were hot pressed at temperatures between 800 oC and 1 750 oC and at a pressure of 50 MPa in vacuum. The effect of the particle size of the starting powders, as well as the effect of the starting compositions and temperature, was investigated. The materials could only densify up to 80 – 92% of the theoretical density. After hot pressing at 800 oC, only Al and cBN could be observed by XRD, whereas higher hot-pressing temperatures resulted in the formation of AlN and AlB2 which retard the densification. The microstructure of the hot-pressed materials was studied using SEM. It was observed that there are oxide layers at the interface between the Al and cBN phases. The presence of these oxide layers prevented the Al from spreading, thereby preventing full densification.

Escorregamentos de taludes no Sudeste do Brasil são causados principalmente, pelo efeito da água proveniente das chuvas. Nos últimos anos, vem se incrementando o número de desastres naturais, ao passo são registradas mudanças climáticas, que podem exercer influência na ocorrência de chuvas extremas. Muitas encostas permanecem grande parte do ano com o solo em estado não saturado, porém variações nas condições ambientais podem ocasionar mudanças bruscas da sucção, reduzindo ou até mesmo eliminando-a e gerando pressões neutras positivas. A dissertação apresenta, um estudo sobre a influência das chuvas, consideradas extremas, no processo de infiltração e de este nos eventos de escorregamentos, considerados catastróficos pela sua dimensão, e que causaram prejuízos ambientais, econômicos e sociais no Brasil. Para o estudo foram selecionados dois eventos de escorregamentos translacionais rasos relativamente típicos, considerados catastróficos, um deles aconteceu na região da Serra de Cubatão em janeiro do ano 1985, e o outro na Região Serrana do Rio de Janeiro em janeiro de 2011. Estes dois eventos apresentaram características de precipitações e mecanismos de escorregamentos próprios, que permitem ilustrar os diferentes mecanismos atuantes em cada caso. / Landslide in southeastern Brazil, are mainly caused by the effect of water from rainfall in infiltration process, in recent years has been increasing the number of natural disasters, while climate change that may exercising influence on the occurrence of extreme rainfall are recorded . Many slopes remain a large part of the year with unsaturated soil condition; however, changes in environmental conditions can cause sudden changes of suction, reducing or even deleting it and generate positive pore pressures. This dissertation presents a study about the influence of rainfall, considered extreme in the infiltration process and this one in the events regarded by their size of catastrophic landslides, which caused environmental, economic and social losses in Brazil. For the study were selected two events of shallow translational landslides relatively typical, considered catastrophic, one of them occurred in the Serra de Cubatão region on January 1985 and the other in the mountainous region of Rio de Janeiro on January 2011. Both events exhibit characteristics of rainfall and sliding mechanisms themselves, allowing illustrate the different mechanisms active in each case.