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Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalystsVENNESTROM, PETER NICOLAI RAVNBORG 14 October 2014 (has links)
With increasing legislative demands to remove nitrogen oxides (NOx) from automotive diesel exhaust, new catalyst systems are investigated and intensely studied in industry as well in academia. The most prevailing catalytic method of choice is the selective catalytic reduction (SCR) where non-toxic urea is used as a reductant for practical reasons. Usually urea is stored in a separate tank and once injected into the exhaust system it hydrolyses into the more aggressive reductant NH3 and CO2.
4 NH3 + 4 NO + O2 -> 4 N2 + 6 H2O (NH3-SCR reaction)
In regions where vanadium is not banned cost effective V2O5/WO3/TiO2 NH3-SCR catalyst systems can be used. Vanadium based are well understood, but they do however not provide stability above ca. 550 °C for longer periods of time. In exhaust treatment systems where the temperature is either high or where high temperature excursions are experienced from e.g. regeneration of particulate filters, zeolite based catalysts are therefore today the most promising candidates as high-temperature stable and non-toxic catalysts for the NH3-SCR reaction.
Among the most promising candidates are the Cu- and Fe-based zeolites. Usually Fe based zeolites show good performance in the temperature range 250-500 °C and reasonable stability, whereas Cu-based zeolites show good low-temperature activity in the 180-400 °C range. The presence of copper does however also lead to a lower stability of the catalyst material. Since the low-temperature activity is of paramount importance it is necessary to improve this behavior. Therefore the purpose of this project is to investigate:
- The deactivation mechanism of copper based zeolites
- The influence of the zeolite framework on stability and activity
These investigations should mostly be carried out on model systems such as Cu-ZSM-5 and Cu-IM-5.
Recently it was found that zeolite materials with the CHA-type structure show increased hydrothermal stability, most likely originating from the small 8-MR window openings in the structure. Part of the project should therefore also include investigations on this type and other similar structures, and therefore entail:
- Synthesis, in-depth characterization and catalytic testing of Cu-SSZ-13 and Cu-SAPO-34 (both structures having the CHA-type framework)
- Theoretical DFT calculations on relevant parameters found by the in-depth investigation of the afore-mentioned materials
- Synthesis and testing of similar materials with 8-MR windows to elucidate the influence of the zeolite sub-structure i.e. if different ring sizes in the structure influences the catalytic performance
Relevant characterization techniques include, besides conventional methods, in situ methods such as: high resolution (transmission) electron microscopy, infrared (and raman) spectroscopy together with X-ray absorption spectroscopy. These are all techniques that will complement each other to produce invaluable results.
Zeolites are today applied in many and diverse applications both within automotive and environmental catalysis, but also within the petrochemical and renewable chemistry. The findings of this project are therefore also believed to contribute to a more comprehensive understanding of this class of materials, relevant to many areas of heterogeneous catalysis, and therefore have the potential, to create research and business with very high impact. / Vennestrom, PNR. (2014). Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/43217
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Einfluss intermetallischer Phasen der Systeme Al-Cu und Al-Ag auf den Widerstand stromtragender Verbindungen im Temperaturbereich von 90 °C bis 200 °CPfeifer, Stephanie 27 October 2016 (has links) (PDF)
Im Netz der Elektroenergieversorgung werden einzelne Netzkomponenten und Betriebsmittel durch Verbindungen elektrisch zusammengeschaltet. Dabei werden häufig Schraubenverbindungen mit Stromschienen eingesetzt. Diese müssen über mehrere Jahrzehnte zuverlässig hohe Ströme tragen können. Abhängig von der sich einstellenden Temperatur an den Verbindungen altern diese mit der Zeit. Die Alterung wird je nach Verbindungssystem von verschiedenen Mechanismen beeinflusst, die alle parallel ablaufen. Bei ruhenden, stationären elektrotechnischen Verbindungen, deren Kontaktpartner aus verschiedenen Materialien bestehen, können abhängig von der Paarung intermetallische Phasen (IMP) entstehen. Die sich bildenden IMP haben schlechtere elektrische und mechanische Eigenschaften als die reinen Metalle. Daraus resultiert ein höherer Verbindungswiderstand. Die erzeugte Verlustleistung sowie die Temperatur der Verbindung steigen an. Dies kann zum Ausfall der Verbindung führen. In der Elektroenergietechnik werden aufgrund ihrer guten elektrischen Leitfähigkeit häufig die Werkstoffe Aluminium und Kupfer sowie das Beschichtungsmetall Silber bei Temperaturen von üblicherweise 90 °C bis 200 °C eingesetzt. Speziell bei Aluminium-Kupfer-Verbindungen, die nicht langzeitstabil sind, wird als maßgebliche Ausfallursache das Bilden von IMP gesehen.
Die IMP des Systems Al-Cu wurden in der Vergangenheit bereits vielfach untersucht. Das Übertragen der Ergebnisse auf die Problematik stromtragender Verbindungen der Elektroenergietechnik ist jedoch nicht ohne Weiteres möglich. Der relevante niedrige Temperaturbereich zwischen 90 °C und 200 °C spielt bei vielen Untersuchungen nur eine untergeordnete Rolle. Zusätzlich können die Eigenschaften der IMP bei unterschiedlichen Herstellungsverfahren voneinander abweichen. Zum System Al-Ag ist in der Literatur nur wenig bekannt. Deshalb wurden für diese Arbeit phasenreine IMP der Systeme Al-Cu und Al-Ag mit unterschiedlichen Herstellungsverfahren bei möglichst identischen Randbedingungen hergestellt. Diese wurden mit einer speziell für diese Proben entwickelten Messeinrichtung elektrisch charakterisiert und der ermittelte spezifische elektrische Widerstand der IMP und ihr Temperaturbeiwert mit Werten aus der Literatur verglichen.
An verschiedenen Schraubenverbindungen mit Stromschienen aus Aluminium und Kupfer wurden Langzeitversuche von bis zu 3 Jahren durchgeführt. Der Verbindungswiderstand wurde abhängig von der Zeit ermittelt. An ausgewählten Verbindungen wurde zusätzlich in zwei identischen Versuchen der Einfluss der Belastung mit Dauer- und Wechsellast auf das Langzeitverhalten untersucht. Mithilfe der an den IMP ermittelten elektrischen Eigenschaf-ten wurde deren Einfluss auf den Verbindungswiderstand berechnet. Die Ergebnisse dieser Modellrechnung wurden mit den Ergebnissen aus den Langzeitversuchen verglichen. Ausgewählte Verbindungen wurden dazu mikroskopisch untersucht. Es wurde festgestellt, dass die IMP nicht ausschließlich das Langzeitverhalten stromtragender Verbindungen bestimmen. Es muss mindestens ein weiterer Alterungsmechanismus einen signifikanten Einfluss haben. Die Untersuchungen deuten darauf hin, dass dabei Sauerstoff eine zentrale Rolle spielen könnte. / In electrical power supply networks a huge number of electrical joints are used to connect transmission lines, conductors, switchgears and other components. During operation these joints are aging due to different aging mechanisms. Depending on the type of the joint several aging mechanisms can take place at the same time. For stationary joints with contact partners made of different materials, the formation of intermetallic compounds (IMC) may be an issue. These IMC have worse electrical and mechanical properties compared to the pure metals. Therefore, the presence of IMC in the contact area results in a higher joint re-sistance and the temperature and the thermal power losses increase. Typical temperatures for high current joints are between 90 °C and 200 °C.
Due to their good electrical conductivity aluminum and copper are often used as conductor materials and silver as a coating material. Especially bimetal joints made of aluminum and copper are not long term stable. The formation of Al-Cu IMC is held responsible as a cause of failure. The IMC of the System Al-Cu have already been studied by several authors. However, it is difficult to apply the results directly to electrical joints in power supply networks. In many studies the low temperature range between 90 °C and 200 °C is not regarded. In addition, the properties of the IMC may vary due to different preparation processes. There is only little information about the system Al-Ag in the literature.
For this work, phase pure IMC of the systems Al-Cu and Al-Ag were prepared by different preparation processes using similar process parameters. These IMC samples were electrically characterized with a specially developed measuring device. The specific electric resistivity and the temperature coefficient of resistance were determined and compared to values taken from the literature. Various combinations of bus bar joints made of aluminum and copper were investigated in long term tests for up to three years. The joint resistance was determined as a function of time.
In addition, for selected joints two identic setups were operated with continuous load and alternating load. The long term behavior was investigated with regard to the load ap-plied. Using the results of the electrical characterization of the IMC their influence on the joint resistance was calculated theoretically. The results of the calculation were compared to the results determined in the long term tests. Selected joints were examined microscopi-cally after termination of the long term tests. It was found, that the long term behavior of bimetal electrical joints with the combination Al-Cu and Al-Ag cannot be exclusively described by the growth of IMC. At least there is one further aging mechanism involved. The studies suggest, that oxygen may have a significant influence.
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Influence de la matière organique dissoute sur la spéciation et la biodisponibilité des métaux : cas de la Seine, un milieu sous forte pression urbaine / Role of dissolved organic matter to metal speciation and bioavailability : the case of the Seine river, one human-impacted systemPernet-Coudrier, Benoît 04 December 2008 (has links)
Ce doctorat s’intègre dans le projet ANR BIOMET (JC05_59809) et a eu pour vocation d’améliorer les connaissances actuelles sur l’influence de la matière organique dissoute sur la spéciation et la biodisponibilité des métaux particulièrement dans le cas de système sous forte pression urbaine tel que la Seine. La compréhension de l’influence de la MOD sur la spéciation et la biodisponibilité des métaux suppose en outre que l’on connaisse précisément sa composition chimique ou plus exactement ses groupements fonctionnels. C’est pourquoi une partie de ces travaux est consacrée à l’extraction et la caractérisation de la matière organique dissoutes d’origine naturelle et urbaine. La caractérisation des fractions de MOD a été réalisée de manière originale par une approche multidimensionnelle à l’aide d’un véritable éventail de techniques analytiques (analyses élémentaires; isotopiques; fonctionnelles et moléculaires) permettant ainsi de mieux aborder l’influence de la MOD sur la spéciation et la biodisponibilité du cuivre et du plomb. Parallèlement à l’étude de caractérisation de la MOD, ce travail s’attache à mieux cerner le rôle de la MOD d’origine urbaine en particulier de la MOD hydrophile sur la spéciation et la biodisponibilité du cuivre et du plomb. Dans cet objectif, les techniques : potentiométrique à l’aide d’électrode ionique spécifique et la récente technique électrochimique AGNES ainsi que des biotests de toxicité aiguë (Daphnia magna) et de bioaccumulation (Fontinalis antipyretica) ont permis : - d’étudier la complexation du cuivre et du plomb par les fractions de MOD obtenues afin notamment de fournir des paramètres de complexations des MOD hydrophiles peu connues jusqu’à présent et ainsi mieux prédire le transport des métaux en milieu urbain. - d’évaluer le rôle protecteur de la MOD d’origine urbaine sur la biodisponibilité du cuivre. Les résultats ont montré que la MOD issue des effluents de station d’épuration et rejetée dans le milieu récepteur présente des caractéristiques originales à savoir un fort pourcentage de MOD hydrophile, c’est à dire une faible hydrophobicité et un degré d’aromaticité peu marqué soulignant le caractère peu réfractaire de cette MOD. En revanche une plus grande diversité fonctionnelle de la MOD d’origine urbaine par rapport à la MOD naturelle a été mise en évidence notamment par un taux de structures protéiques très important. Les résultats obtenus ici pour la première fois vis-à-vis des MOD hydrophiles d’origine urbaine ont montré une réactivité particulière vis-à-vis du cuivre. En effet les fractions HPI et plus généralement les fractions issues des effluents de station d’épuration ont montré une teneur en sites complexants plus élevée que ce qu’il avait été déjà observé pour des matières organiques naturelles. Les valeurs des constantes ne semblent pas varier d’une fraction à l’autre et assez peu suivant l’origine de la MOD. Le rôle particulier de l’azote dans la complexation du cuivre notamment sous la forme de groupements amines a été mis en évidence. Les approches utilisées pour évaluer la biodisponibilité du cuivre ont révélé pour l’ensemble des fractions de MOD un effet protecteur vis-à-vis du cuivre sur les organismes vivants. Néanmoins cet effet protecteur ne se trouve pas à la hauteur de celui pouvant être prédit par le modèle de l’ion libre principalement dû à une biodisponibilité de certains complexes organiques. Ceci peut être expliqué par l’important taux de structures protéiques dans ces MOD, les protéines étant connues pour jouer un rôle important dans les mécanismes de transports des métaux au sein des organismes. Par ailleurs, l’outil DGT (Diffusive gradient in thin films) a montré son efficacité pour évaluer la fraction biodisponible du cuivre / This thesis was carried out on the framework of the ANR BIOMET research project (JC05_59809). The main objectives were to improve the current knowledge on the influence of dissolved organic matter (DOM) on metal speciation and bioavailability in urban aquatic system. The understanding of the influence of DOM on trace metal speciation and bioavailability required that the chemical composition of DOM, more exactly its binding sites should be well understood. Therefore, one part of this research focused on the isolation and characterization of DOM. The characterization of DOM, with a multidimensional approach was realized with a lot of various techniques (such as elemental, isotopic, functional and molecular) that were of prime importance to better understand the influence of DOM on trace metal speciation and bioavailability. To accomplish these objectives, the techniques such as potentiometry with ionic selective electrode and the recent electroanalytical technique AGNES and bioassays such as a bioaccumulation test (Fontinalis antipyretica) and an acute toxicity test (Daphnia magna) were performed in order to: - study the copper and lead binding by isolated DOM fractions in order to give some binding parameters of hydrophilic DOM and to better predict the fate of the trace metal. - evaluate the protective role of urban DOM on copper bioavailability. Results showed some particular characteristics of DOM from wastewater effluent such as a high proportion of hydrophilic DOM, i.e. a low hydrophobicity and a low degree of aromaticity underlying the low refractory character of urban DOM. Nevertheless a higher content of various functional groups was determined in urban DOM than in natural DOM. A very high content of proteinaceous structures was particularly identified in urban DOM. Binding experiments revealed for the first time on urban hydrophilic DOM, a higher content of binding sites than in natural DOM and these sites are strongly correlated to amino groups. The values of binding constant seem to not vary according to the nature of the fraction or the origin. The different approaches used to evaluate copper bioavailability depicted a protective role of DOM to the organisms Daphnia magna and Fontinalis antipyretica. Nevertheless this protective effect is hardly explained by the free ion concentration due to a bioavailability of some organic complexes. This feature could be explain with the high content of proteinaceous structures in these DOM fractions, since proteins are well know to play an important role in the transport mechanisms of trace metals into the organisms. Moreover, the DGT device (diffusive gradient in thin films) shows a good efficiency to assess the bioavailable copper
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Etude ab initio d'alliages AlCu : phénomènes de ségrégation et modification de la réactivité de surface vis-à-vis de O / Ab initio study of Al/Cu alloys : segregation phenomena and modication of the surface reactivity towards oxygenBenali, Anouar 03 December 2010 (has links)
En présence d'éléments d'alliage, l'aluminium présente d'excellentes propriétés mécaniques, obtenues grâce à un durcissement structural (alliages Al/Cu/Mg). Ces alliages constituent ainsi des matériaux largement utilisés dans le domaine de l'aéronautique. De plus, l'aluminium possède la capacité à former en présence d'oxygène un oxyde très stable qui conduit à des revêtements utilisables à hautes températures et présentant une bonne résistance à l'oxydation et à la corrosion dans un environnement agressif. Vu les enjeux économiques associés à ces propriétés, la compréhension des phénomènes à l'origine de la formation et de la microstructure des dépôts ainsi que l'influence de la présence du cuivre dans une surface d'aluminium sur l'adsorption de l'oxygène méritent d'être approfondie. Les deux axes principaux de l'étude théorique que nous présentons sont l'étude de la ségrégation du cuivre dans l'aluminium et l'étude de l'adsorption de l'oxygène atomique sur des surfaces d'alliages Al-Cu. La théorie de la fonctionnelle de la densité est actuellement la méthode ab initio la plus adaptée pour accéder aux propriétés énergétiques et électroniques de ces systèmes. Pour une concentration massique en Cu inférieure à 4%, le diagramme des phases expérimentale Al/Cu montre la formation d'une solution solide α. Une augmentation de la concentration en cuivre entraine la précipitation de cuivre sous la forme de zones de Guinier-Preston1 et 2 (GP1 et GP2) puis du premier composé déni Al2Cu (θ' métastable, puis θ stable). Nos calculs montrent que pour des phases à des concentrations en cuivre inférieures à 4%, une tendance à la formation d'une solution solide est observée en accord avec le diagramme des phases expérimentale. Nous discutons la stabilité d'alliages ordonnés Al/Cu en fonction de l'orientation de la surface, de la concentration en atomes de cuivre et de leur position par rapport à la surface. Les systèmes étudiés sont constitués d'une couche d'alliage dans un massif d'aluminium. Des atomes de cuivre sont dans un premier temps substitués à l'aluminium en surface. Cette couche est par la suite enterrée dans le massif. Les énergies de ségrégation calculées indiquent que le système est plus stable quand les couches d'alliage sont enterrées proche de la surface. La même tendance est observée pour les zones de GP1 et GP2, modélisées par des agrégats de 3 atomes de cuivre orientés selon la direction (100) dans l'aluminium (111). La substitution d'une monocouche complète de cuivre dans une surface Al(100) montre quant à elle une ségrégation du cuivre loin de la surface. L'ensemble des résultats indique clairement que les propriétés géométriques et énergétiques des systèmes Al/Cu sont nettement dominées par une tendance préférentielle du cuivre à ségréger proche de la surface Al(111). Les surfaces nues ayant été étudiés, nous nous sommes ensuite intéressés à l'adsorption de cuivre puis d'oxygène atomiques. Nous avons mis en évidence l'adsorption thermodynamiquement favorisée du cuivre en positions cfc, hcp et ponté sur une surface Al(111). L'adsorption est liée à un fort transfert électronique de la surface du matériau vers l'adsorbat. Ce comportement est encore plus fort dans le cas de l'adsorption de l'oxygène sur l'aluminium pur. En présence de cuivre, l'énergie d'adsorption de l'oxygène est fortement réduite (déstabilisation du système). Ce phénomène est d'autant plus important que le cuivre sera proche de la surface d'aluminium et donc de l'adsorbat. Hormis la répulsion électrostatique, nous n'observons néanmoins aucune interaction entre l'atome de cuivre et l'atome d'oxygène. La diminution de l'énergie d'adsorption de l'oxygène résulte essentiellement de la compétition entre les transferts électroniques vers le cuivre et l'oxygène à partir de la surface de l'aluminium. / Aluminum is often alloyed to modify some of its intrinsic properties and various treatments such as precipitation hardening are needed to improve its mechanical properties (Al/Cu/Mg alloys). The properties of these alloys are not due simply to their chemical composition but are particularly influenced by the involved phases and the alloy microstructure. Copper-aluminum alloys that have good mechanical properties are the most used alloys in the aeronautical field. Aluminum has also the capacity to form a very stable oxide. Thus, it leads to high temperature resistant coatings with good resistance to oxidation and corrosion in aggressive environments. Therefore, investigating the origins of the microstructure and the formation of the clusters as well as the influence of the copper atoms in the aluminum surface, on the oxygen adsorption is of crucial importance to comprehend these phenomena at larger scales. This study investigates theoretically in one hand, the copper segregation in aluminum and on the other hand, oxygen adsorption on Al-Cu surface alloys. This work is carried out in the framework of the density functional theory, which is at the moment the most adapted ab initio method to deal with the structural and electronic properties of these systems. According to the Al/Cu equilibrium phase diagram, at Cu atomic concentration lower than 4%, one is in presence of a solid solution α. When increasing the Cu concentration in the Al matrix, the Cu first precipitate within the bulk into Guinier-Preston1 and 2 (GP1 et GP2) zones and that later transformed to Al2Cu (metastable θ' and stable θ phases). At low copper concentration (<4%at.), we observe a tendency to the formation of a solid solution at T=0 K. We investigated surface alloys properties for varying compositions of a Cu doped Al layer in the Al (111) surface then buried in the slab. Calculated segregation energies show that the systems are more stable when the Cu doped layer is buried close to the surface. The same results are observed for first stage formation of GP zones, modelled by doping Al (100) layers with Cu clusters in a Al (111) slab. However the segregation of a full copper (100) monolayer in an Al (100) matrix shows a copper segregation deep in the bulk. Our results fit clearly into a picture of energetics and geometrical properties dominated by preferential tendency to Cu-clustering close to the Al (111) surface. Clean surfaces being fully described, we studied the adsorption of copper and oxygen atoms on clean Al (111) surface. We highlight a thermodynamically favoured adsorption of copper atoms on Al (111) surface upon fcc, hcp and bridge adsorption hollow-sites. The adsorption is related to the electronic transfer from the surface towards the adatom. The adsorption is even stronger when adsorbing oxygen on Al (111) surface. Nevertheless, in the presence of copper, the oxygen adsorption energy is weaker (destabilization of the system). The energy decrease is even more important as the copper is close to the surface, hence the adatom. Aside from the electrostatic repulsion, we observe no interaction between the copper and the oxygen atoms. The adsorption energy diminution is essentially due to the competition between the electronic transfers towards the copper and the oxygen from the aluminum surface.
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Etude structurale et gîtologique du gisement de sulfures massifs à métaux de base de Hajjar : contribution à l'histoire tectono-métamorphique des Guemassa orientales, Maroc / Structural and gitological study of the Hajjar massive base metal sulfide deposit : contribution to the tectono-metamorphic history of Eastern Guemassa, MoroccoAdmou, Safouane 08 December 2018 (has links)
Les gisements de sulfures massifs encaissés dans les massifs hercyniens marocains des Jebilets et Guemassa sont de type (VMS) déformés et métamorphisés. Il manque toutefois une évaluation de la contribution de cette déformation à leur structuration actuelle, et l’éventuel impact de celle-ci sur le plan économique et en termes d’exploration. Par conséquent, cette contribution vise principalement à définir le contexte structural de ces minéralisations, en vue d’en déduire un modèle structural relatif au VMS de Hajjar.Le VMS de Hajjar, appartenant au domaine des Guemassa (Meseta occidentale). Il est encaissé dans des terrains d’origine volcanosédimentaire composés de pélites, de grès et de lentilles et barres calcaires intrudés par des sills et dykes felsique et basique. Les principaux corps volcaniques correspondent aux dômes rhyolitiquesLe gisement de Hajjar est composé de 3 corps minéralisés : le corps principal (CP), le corps Nord-Est (CNE) et les corps ouest et extrême ouest descenderie (CWD, CEWD). Le gisement de Hajjar est affecté par un seul plan XY d’aplatissement subvertical de directions N0 à N45. L’encaissant et les corps sulfurés présentent les mêmes assemblages métamorphiques silicatés, qui présentent soit une texture granoblastique « statique » lorsque la déformation est faible, soit des caractéristiques prés à syn-tectoniques lorsque la schistosité est fortement exprimée. La texture, les formes des biotites et d'andalousites (± cordiérite suspectée) sont typiques du métamorphisme de contact HT / BP des faciès de cornéennes. L'assemblage syntectonique est composé de quartz + chlorite + micas blancs (± calcite), et remplace partiellement les anciennes biotites et andalousites. Les données de surface du bloc N'Fis montrent la présence d'un seul plan XY subvertical orienté N130. Les biotites du métamorphisme de contact sont allongées parallèlement à la schistosité. L’ensemble des données indiquent que le VMS de Hajjar et le bloc N'Fis sont affectés par une seule schistosité qui est synchrone d’un métamorphisme de contact de HT / BP. La virgation importante de la schistosité des affleurements d'Imarine au VMS de Hajjar est dû à une importante zone de cisaillement - transpressive de direction ENE-WSW. Près de la mine Hajjar, une telle zone de cisaillement à l’échelle régionale est reconnue pour la première fois, et constitue une caractéristique structurale-clé du district de Hajjar.La minéralisation de Hajjar est fortement déformée et métamorphisée. Elle est affectée par le plissement, la schistosité et la mylonitisation dans un contexte cisaillant. Les structures minéralisées stratiformes sous forme de rubans riches en pyrrhotite précèdent clairement la déformation et le métamorphisme de contact. D’autres structures minéralisés riche en (Zn, Cu, Pb) présentent un rubanement tectonique issu de la remobilisation par fluide de la minéralisation précoce Le stade précoce est caractérisé par la précipitation de la pyrrhotite, pyrite, arsénopyrite, sphalérite et la galène, alors que le stade syncinématique constitue l’événement concentrateur majeur caractérisé par la dissolution et la recristallisation de la paragenèse précoce avec un enrichissement en Zn, Cu. Le stade tardif post-cinématique est responsable la néoformation de sulfures, à savoir la chalcopyrite, la pyrite et quelques traces de sphalérite.Nous avons mis en évidence un épaississement tectonique dans les zones de charnières. Le métamorphisme pré à syntectonique favorise le comportement ductile et la recristallisation des sulfures (Po, Cpy et Sph). Les veines triangulaires polymétalliques à l'extrémité des lentilles de sulfures massifs sont le témoin d'une remobilisation hydrothermale assistée par un fluide pendant la déformation. L’ensemble de nos études débouche sur la proposition d’un modèle 3D tectonométamorphique pour le VMS des Guemassa et des propositions pour rechercher des extensions de la minéralisation. / The massive sulphide deposits hosted in the Moroccan Hercynian massifs of Jebilets and Guemassa are Volcanogenic Massive Sulfide (SMV), deformed and metamorphosed. However, an assessment of the contribution of this deformation to their current structure and the eventual impact on the economy and in terms of exploration is missing. Therefore, this contribution aims mainly to define the structural context of these mineralizations, in order to deduce a structural model relating to Hajjar's VMS.The VMS of Hajjar, belonging to the domain of Guemassa (Western Meseta). It is hosted in volcanosedimentary terrain composed of pelites, sandstones and lentils and limestone bars intruded by felic and basic sills and dykes. The main volcanic bodies correspond to the rhyolitic plugs.The Hajjar deposit is composed of 3 mineralized bodies: main body (CP); north-eastern body (CNE); western body (CWD) and extreme western body(CEWD.). The Hajjar deposit is affected by a single XY plane of subvertical flattening of directions N0 to N45. The host rock and sulphide bodies have the same silicate metamorphic assemblages, which exhibit either a "static" granoblastic texture when the strain is low or pre to syn-tectonic features when the foliation is strongly expressed. The texture shapes, and aggregates of the biotite and andalousite (± suspected cordierite) are typical of HT/LP “contact” metamorphism in the hornfels facies. The syn-tectonic assemblage is composed of quartz + chlorite + white micas (± calcite) and partially replaced the former biotite and andalousite blasts. The data from the N’Fis block show the occurrence of a single sub-vertical XY plane oriented N130. The biotites of contact metamorphism are elongated parallel to the foliation. These data imply that the Hajjar MSD and the N’Fis block are affected by a single foliation which encompasses a HT/LP contact metamorphism. The significant inflexion of foliation from Imarine outcrops to Hajjar VMS is due to major right-lateral ENE-trending transpressive shear zone at Hajjar. Near the Hajjar mine, such a regional shear zone is recognized for the first time, and is a structural key feature of the Hajjar district.The mineralization of Hajjar is strongly deformed and metamorphosed. It is affected by folding, foliation and mylonitic bands within a regional scale shear zone. Structures such as pyrrhotite-rich ribbons clearly pre-date the deformation and the HT/LP contact metamorphism. The early stage is characterized by the precipitation of pyrrhotite, pyrite, arsenopyrite, sphalerite, and galena, whereas the synkinematic stage constitutes major concentrator event characterized by the dissolution and recrystallization of early paragenesis with enrichment in Zn, Cu. The late post-kinematic stage is responsible for the neoformation of sulphides, namely chalcopyrite, pyrite and some traces of sphalerite.We have demonstrated a tectonic thickening within the fold hinge zone. pre-syntectonic metamorphism favors ductile behavior and sulfide recrystallization (Po, Cpy, and Sph). The polymetallic veins argue for hydrothermal fluid-assisted remobilization during deformation. All of our studies lead to the proposal of a 3D tectono-metamorphic model for the VMS of Guemassa and proposals to search extensions of the mineralization.
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Etude et mise au point de composants magnétiques multicouches pour intégration en électronique de puissance / Study and development of multilayer magnetic components for power electronics applicationBrun, Edouard 07 October 2014 (has links)
Ces dernières années, les besoins en électronique de puissance s’orientent vers la miniaturisation globale des cartes électroniques, parallèlement à une augmentation des puissances de travail. C’est dans ce contexte que s’inscrivent les travaux de cette thèse, principalement axée sur l’élaboration, l’amélioration des performances et l’intégration de composants passifs (inductances, transformateurs…) en électronique de puissance.Les matériaux choisis pour remplir les fonctions magnétiques de ces composants dans leurs conditions de travail sont les ferrites NixZn1-xFe2O4 (0<x<1). Du cuivre est ajouté pour diminuer la température de frittage, de plus de 1200 °C à moins de 950°C, permettant le cofrittage avec un métal conducteur, et du cobalt pour diminuer les pertes totales en puissance du ferrite formé. La formulation finale devient alors (NixZnyCuz)1-εCoεFe2-δO4 (x+y+z=1). Enfin, de l’oxyde de bismuth Bi2O3 est ajouté comme fondant pour abaisser encore la température de frittage et éviter les problèmes de diffusion.Après une étude bibliographique, les travaux se sont orientés selon différents axes. Il s’agissait tout d’abord d’optimiser la formulation du ferrite pour élaborer des échantillons aux propriétés électromagnétiques et physicochimiques ciblées. Cet axe de travail regroupe de nombreuses études sur la formulation des ferrites Ni-Zn-Cu-Co, parmi lesquelles les principales sont l’étude de l’influence de la stœchiométrie en fer, du rapport Ni/Zn dans la formulation et du procédé d’ajout de cobalt selon son taux. Ces travaux ont permis de mettre en évidence qu’un léger défaut de fer maîtrisé (~Fe1,98) pouvait améliorer les propriétés et les performances de ces ferrites. L’étude de l’influence du rapport Ni/Zn a permis la réalisation de ferrites à perméabilités très faibles, de 40 à 135, et aux bonnes performances en puissance. Les résultats de cette étude ont été publiés dans le Journal of the Japan Society of Powder and Metallurgy. Tout au long de la thèse, l’élaboration d’échantillons céramiques, base incontournable de chaque étude, a été réalisé au laboratoire, comme la plupart des tests et caractérisations. Ces derniers peuvent être microstructuraux et physicochimiques (DRX, MEB, BET, ATD/ATG…), ou électromagnétiques (mesures d’aimantation, de perméabilité, de pertes en puissances, etc…).La finalité de ces travaux étant l’intégration de puissance, cette dernière représente le second axe majeur, et regroupe également de nombreuses études, parmi lesquelles les principales sont les études des influences du bobinage sur les pertes d’un composant de type inductance et de l’entrefer (espacement amagnétique au sein du circuit magnétique), classiquement utilisé pour diminuer la perméabilité apparente, non sans conséquence sur les performances en puissance. Une campagne de mesures de pertes totales a également été réalisée dans l’objectif de dégager des lois comportementales sur la variation de ces pertes en puissance et en fréquence.Tous ces travaux et leurs résultats sur le matériau ferrite, son utilisation en électronique de puissance, et une bonne maîtrise du procédé d’élaboration (notamment multicouche), ont permis la réalisation de microcomposants passifs intégrables, aux propriétés ciblées et aux très bonnes performances (pertes diminuées d’un facteur 6 à 10 par rapport au commerce). / In recent years, power electronics needs are moving towards the global miniaturization of electronic boards, and an increase of the working powers. The works performed during this thesis, mostly oriented on the elaboration, the performances improvement and the integration of passive components (inductors, transformers…) in power electronics, are inscribed in this context.The materials chosen to perform the magnetic functions of those components in their work conditions are the NixZn1-xFe2O4 (0<x<1) ferrites. Copper is added to reduce the firing temperature, from more than 1200 °C to less than 950 °C, allowing cofiring with a conducting metal, and cobalt is added to reduce the power core losses of the sintered ferrite. The final formulation then becomes (NixZnyCuz)1-εCoεFe2-δO4 (x+y+z=1). Finally, bismuth oxide Bi2O3 is added as a sintering aid to lower even more the sintering temperature and avoid diffusion problems.After a bibliographic study, the works were oriented along different axes. Firstly, the ferrite formulation was optimized to elaborate samples with targeted electromagnetic and physicochemical properties. This working axis gathers numerous studies on the Ni-Zn-Cu-Co ferrites formulation, among which the main ones are the study of the influence of iron stoichiometry, the Ni-Zn ratio in the formulation and the cobalt adding process and level. These studies have shown that a light and controlled iron deficiency (~Fe1,98) could improve the properties and the performances of these ferrites. The study of the influence of the Ni/Zn ratio allowed the production of very low permeability ferrites, from 40 to 135, with good power performances. Its results were published in the Journal of the Japan Society of Powder and Metallurgy. Throughout this thesis, the elaboration of ceramic samples, the essential basis of every study, was undertaken at the laboratory, as most of the tests and characterizations. These can be microstructural and physicochemical (XRD, SEM, BET, TDA/TGA…), or electromagnetic (magnetization and permeability measurements, power losses…).The final purpose of this work is power integration, and it represents the second main axis. It also gathers many studies, among which the main ones are the study of the influence of the winding on the losses of an inductor-type component and the influence of the air gap, commonly used to reduce the apparent permeability, not without consequences on the power performances. A total losses measurement campaign has also been undertaken in order to bring out behavioral laws on core losses variation according to induction and frequency.All this work and the results on the ferrite material, his power electronic application, and a good control of the elaboration process (multilayer especially), allowed the production of passive micro-components for integration, with targeted properties and very high performances (core losses reduced by 6 to 10 relative to commercial materials).
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Avaliação da contribuição das fontes poluentes para a assinatura isotópica de Pb, Zn e Cu do aerossol atmosférico da cidade de São Paulo / not availableSouto-Oliveira, Carlos Eduardo 12 May 2017 (has links)
As altas concentrações de aerossol fino e ultrafino observadas na atmosfera de áreas urbanas possuem um importante papel no clima local e global, devido sua interação com a radiação solar e também pela característica de formação dos núcleos de condensação de nuvens (CCN). Essas altas concentrações de partículas são responsáveis pela poluição do ar, atualmente considerada como o principal problema ambiental para a saúde pública no mundo, sendo relacionada ao câncer, doenças respiratórias, cardiovasculares e o mal de Alzheimer. Nesse contexto, o presente trabalho almejou a caracterização e discriminação de fontes poluentes para o aerossol atmosférico da cidade de São Paulo, utilizando os isótopos de Pb, Zn e Cu simultaneamente. Além disso, nesse estudo também foi realizada a avaliação do efeito das fontes locais e remotas para a ativação do CCN na atmosfera dessa região. São Paulo é a maior cidade da Região Metropolitana de São Paulo (RMSP), que por sua vez é a maior megacidade da América do Sul, e está entre as dez maiores do mundo. Amostras de aerossol urbano foram coletadas no inverno de 2013 e verão de 2014 na cidade de São Paulo. Ao mesmo tempo foram coletadas, em São Paulo e Cubatão, amostras de fontes poluentes importantes para a RMSP, como aquelas relacionadas ao tráfego veicular (combustíveis, pneu, poeira de rua e aerossol de túnel), construção civil (cimento) e à área industrial de Cubatão (aerossol). Adicionalmente, foram medidas no inverno de 2014 a concentrações de CCN, a distribuição por tamanho e a concentração em número das partículas. As determinações das composições isotópicas de Pb, Zn e Cu foram realizadas com um novo procedimento analítico, desenvolvido para a separação sequencial e purificação desses elementos, a partir de uma mesma solubilização de amostra, seguida pelas análises por espectrometria de massas empregando MC-ICP-MS e TIMS. A validação da exatidão e precisão desse procedimento foi realizada pela análise de amostras de materiais de referência, aerossol e fontes poluentes. Com base nos dados isotópicos das fontes poluentes, o tráfego veicular foi diferenciado da área industrial de Cubatão utilizando as assinaturas isotópicas de Pb dessas fontes, que demonstraram grande reprodutibilidade quando comparadas com estudos anteriores. Adicionalmente, as assinaturas isotópicas da poeira de rua e dos pneus foram discriminadas das emissões veiculares em um diagrama \'delta\'66ZnJMC vs 206Pb/207Pb. As assinaturas isotópicas de Zn e Cu da poeira de rua, emissões veiculares e cimento foram discriminadas em um diagrama \'delta\'65CuNIST vs \'delta\'66ZnJMC. As contribuições das fontes para as composições isotópicas de Pb e Zn, determinadas no aerossol da cidade de São Paulo, foram quantificadas utilizando modelos de mistura ternária. Nesses modelos o tráfego veicular (57 a 66%) foi predominante, seguido pela fonte não-caracterizada (25 a 32%), que mostrou uma assinatura isotópica de Pb e Zn específica observada nas duas campanhas. A área industrial de Cubatão apresentou contribuições de 11 a 17%, enquanto a poeira de rua contribuiu em até 18% para as assinaturas de Pb e Zn no aerossol. No inverno de 2014, o tráfego veicular local, o sal marinho e a queima de biomassa foram identificadas nas amostras de aerossol por análises de PMF, trajetórias de massas de ar e pelo sistema lidar. Também foram observados eventos de formação de aerossol secundário em 35% dos dias de medição. A ativação de CCN foi menor durante o dia em relação ao período noturno, sendo esse padrão associado principalmente as emissões do tráfego veicular local. Comparando os dias com contribuições das fontes remotas, pôde-se concluir que o material particulado proveniente do tráfego veicular durante o dia mostrou o maior efeito nos parâmetros de ativação de CCN em comparação com as fontes remotas de sal marinho e queima de biomassa. / Fine and ultrafine aerosol particles in high concentrations found in the atmosphere of urban areas, play an important role in local and global climate through interaction with solar radiation and cloud condensation nuclei (CCN) formation. These high concentrations of particles are related to the air pollution, which is the major environmental problem to the public health in the world, related with cancer, cardiovascular, respiratory and Alzheimer diseases. In this context, this study reports the simultaneous use of Pb, Zn and Cu to characterize and discriminate pollutant sources of the atmospheric aerosol from São Paulo City and evaluate the effect of local and remote sources to CCN activation in the atmosphere of this area. São Paulo is the main city of Metropolitan Area of São Paulo (MASP), which is the largest megacity in South America and rank among the ten most populous in the world. Urban aerosol samples were collected during winter of 2013 and summer of 2014 in the São Paulo city. At the same time, samples of the main pollutant sources of MASP, were sampled in São Paulo and Cubatão, such as vehicular traffic (fuels, tyres, road dust and tunnel aerosol), construction (cement) and aerosol from Cubatão industrial area. In addition, CCN concentrations, particle number concentrations and size distributions were measured during the winter of 2014 in the same sampling site. The Pb, Zn and Cu isotopic composition were determined by a new analytical procedure, developed to sequential separation of these elements, using a unique sample dissolution, followed by mass spectrometry analysis by MC-ICP-MS and TIMS. Analytical procedure validation of Accuracy and precision was carried with reference materials, aerosol and pollutant source samples. Based on isotopic data obtained on the pollutant sources, vehicular traffic was differentiated from Cubatão industrial area, using Pb isotopic fingerprints of this sources, which showed long term reproducibility when compared with previous studies. In addition, road dust and tyre isotopic signatures were discriminated from vehicular emissions in a \'delta\'66ZnJMC vs 206Pb/207Pb four isotope plot. Interestingly, Zn and Cu isotopic fingerprints of road dust, vehicular emission and cement was distinguished in a \'delta\'65CuNIST vs \'delta\'66ZnJMC four isotope plot. In order to quantify contributions of sources to Pb and Zn isotopic compositions determined in aerosol from São Paulo city, ternary mixing models were performed. In these models, vehicular traffic accounted to the main contribution (57 to 66%), followed by non-characterized source (25 to 32%), with a specific Pb and Zn isotopic signature identified in aerosol during the two campaigns. Cubatão industrial area showed contributions of 11 to 17%, whereas road dust contributed 18% to Pb and Zn isotopes in aerosol. In the winter of 2014, local vehicular traffic, sea salt and biomass burning were identified in aerosol by PMF, air masses trajectories and lidar analysis. Some new particle formation (NPF) events were identified on 35% of the sampling days. CCN activation was lower during the daytime compared to nightime periods, a pattern that was found to be associated mainly with local road-traffic emissions. Comparing the days with remote sources events, we concluded that particulate matter from local vehicular emissions during the daytime have a greater effect on CCN activation parameters than that from sea salt and biomass burning remote sources.
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Estudo da autoxidação dos complexos de Cu(II), Ni(II) e Co(II)/tetraglicina induzida por S(IV) / Study of the autoxidation of the complexes of Cu (II), Ni (II) and Co (II)/tetraglycine induced by S(IV)Sebastian, Maria Vespertina Alipazaga 19 September 2003 (has links)
O presente trabalho apresenta estudos espectrofotométricos relacionados à autoxidação dos complexos de Cu(II), Ni(II) e Co(II)/tetraglicina induzida por sulfito. Nossos estudos verificaram que a autoxidação de Cu(II)/tetraglicina (1,0x10-3 mol L-1) em pH = 9,0 (tampão borato) é afetada pela presença de traços de Ni(II) ou Co(II). Na ausência de Ni(II) ou Co(II), a reação é muito ineficiente e lenta com períodos de indução longos (aproximadamente 4 h). Ni(II) ou Co( II) em concentrações baixas ( 10-5 - 10-6 mol L-1) afetam significativamente a cinética: o período de indução diminui drasticamente (a menos de 2 s) e a formação de Cu(III) é fortemente acelerada com simultâneo aumento da eficiência da reação. A atividade catalítica e o sinergismo positivo de Co(II) e Ni(II) podem ser explicados pela oxidação mais rápida de Co(II) ou Ni(II)/tetraglicina pelo oxigênio dissolvido. O processo eletroquímico relacionado aos sistemas Cu(II)/Cu(III)/tetraglicina e Ni(II)/Ni(III)/tetraglicina são reversíveis, possibilitando monitorá-los adequadamente mediante o uso da técnica de eletrodo rotativo disco-anel. Entretanto, o sistema Co(II)/Co(III)/tetraglicina é irreversível. Esses estudos mostraram que as espécies de Cu(III) e Ni(III) geradas no eletrodo disco são instáveis nas condições experimentais empregadas. O efeito sinérgico positivo na presença de Ni(II) (que permitiu aumentar a sensibilidade) foi aproveitado para desenvolvimento de método espectrofotométrico e amperométrico simples e sensível para a determinação indireta de sulfito em meio aquoso. O método espectrofotométrico está baseado na medida de absorbância do complexo de Cu(III)/tetraglicina (gerado na presença de sulfito e traços de Ni(II)) em 365 nm. O método amperométrico em análise por injeção em fluxo baseia-se na medida de corrente (0,1 V vs Ag/AgCl) em função da concentração de Cu(III)/tetraglicina gerado quimicamente, na presença de sulfito e traços de Ni(II). Os métodos desenvolvidos foram empregados para a determinação de S(IV), em vinhos e sucos, após a sua extração da amostra acidificada, os resultados obtidos concordaram com aqueles obtidos pelo método iodométrico. / The present work presents spectrophotometric studies related to the sulfite induced autoxidation of Cu(II), Ni(II) and Co(II)/tetraglycine complexes. The sulfite induced autoxidação of Cu(II)/tetraglycine (1.0x10-3 mol L-1) at pH = 9.0 (borate buffer) is affected by the presence of small quantities of the Ni(II) or Co(II). In the absence of added nickel (II) or cobalt (II), the reaction is very inefficient and slow with one large induction period (about 4 h). Trace amounts of Ni(II) or Co(II) (10-5 - 10-6 M) affect the kinetic significantly: the induction period drastically decreases (less than 2 s) and the formation of Cu(III) is strongly accelerated. The effectiveness of Cu(III) formation becomes much higher. The catalytic activity and the positive synergism of Co(II) and Ni(II) may be explained by the faster oxidation of Co(II) or Ni(II)/tetraglycine complexes by dissolved oxygen. The electrochemistry of Cu(II)/Cu(III)/tetraglycine and Ni(II)/Ni(III)/tetraglycine systems are reversible, such as it was possible to monitor them by using the rotating ring-disk electrode technique. However, the Co(II)/Co(III)/tetraglycine system is irreversible. Those studies showed that the Cu(III) and Ni(III) species generated on the disk electrode are unstable in the employed experimental conditions. The positive sinergistic effect in the presence of Ni(II) (which allowed to increase the sensibility) was taken in advantage for development of one simple and sensitive spectrophotometric and amperometric method for indirect determination of sulfite in aqueous medium. The spectrophotometric method is based on the absorbance measurement of the Cu(III)/tetraglicyne complex (generated in the presence of sulfite and small quantities of Ni(II)) at 365 nm. The amperometric method by flow injection analysis is based on the current measurement (0.1 V vs Ag/AgCl) as function of Cu(III)/tetraglycine concentration chemically generated, in the presence of sulfite and Ni(II). The methods were employed for the determination of S(IV), in wines and juices, after its extraction from acidified samples and the results were in agreement with those obtained by the iodometric procedure.
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Differenzielle Wirkung und Wirkungsweise dialektisch-behavioral orientierter Therapie der Borderline-Persönlichkeitsstörung aus PatientenperspektiveMeißner, Jeannette 20 January 2015 (has links)
Ziel: Nach einem Jahr dialektisch-behavioral orientierter Behandlung von Borderline Patienten im ambulanten Setting werden verschiedene Wirksamkeitskriterien und Therapieprozessvariablen, wie die Qualität der Therapieallianz aus Patientenperspektive untersucht. Methode: In einer naturalistischen Studie absolvierten 47 Borderline-Patienten eine DBT-orientierte Behandlung. Das Therapieergebnis wurde mittels indirekten und direkten Veränderungsmaßen, wie Patientenziele erfasst. Prozessvariablen wurden qualitativ mittels halbstrukturierter Interviews nach einem Jahr Therapie untersucht, wobei 28 Interviews in die Analyse einflossen. Speziell die Therapiebeziehung wurde zusätzlich quantitativ mit Hilfe des Working-Alliance-Inventory erfasst, welcher nach jeder Therapiesitzung erhoben wurde. Quantitative wie qualitative Analysen wurden integriert. Ergebnisse: Die meisten Patienten zeigten im Behandlungsverlauf Fortschritte innerhalb direkt, wie auch indirekt erhobener Therapieerfolgsmaße. Die Therapieallianz steht dabei in positivem Zusammenhang mit der Therapiezielerreichung und einigen BPS-relevanten Symptomen, nicht jedoch mit Reduktion von Selbstverletzung/Suizidalität. Die qualitativen Analysen der retrospektiv erlebten Wirkfaktoren zeigen hilfreiche und weniger hilfreiche Aspekte im Therapieverlauf, wobei Beziehungsfaktoren und Therapeutenvariablen durch die Patienten als besonders wichtig bewertet werden. Schlussfolgerung: Aus Patientenperspektive wird die Bedeutung der Therapieallianz hervorgehoben, die mit der Erreichung individuell definierter Therapieziele und der Reduktion einiger borderline-typischer Symptome in Verbindung steht. Die Therapieallianz wird aus Patientenperspektive vor allem durch therapeutische “Soft Skills”, wie Empathie, Selbstoffenbarung und Verständnis geformt. Darüber hinaus wird die Fähigkeit des Therapeuten, sich auf die Bedürfnisse des Patienten einzulassen und verschiedene DBT-spezifische Fertigkeiten vermitteln zu können betont. / Objective: To investigate the patient`s perspective about the key mechanisms of change, especially the quality of the therapeutic alliance and to analyse different criteria of outcomes in the first year of out-patient dialectical behavioral therapy. Method: Participants were 47 outpatients diagnosed with BPD, who enrolled in a naturalistic trial of DBT. Severity of symptoms were assessed at intake and one year after beginning of treatment. Direct and indirect methods of measurement were used, for example individual goals from patients perspective. Alliance was assessed with the Working-Alliance-Inventory for patient´s perspective for every session and in addition with a qualitative interview after one year for 28 persons of the sample. Furthermore the interview includes all more or less helpful aspects of the process of psychotherapy. The research integrates quantitative and qualitative methods. Results: Patients showed positive changes over the course of treatment measured with direct and indirect methods. Results indicate an association between alliance and some BPD symptoms and achievement of individual goals but not self-injurious acts or suicide attempt. The qualitative analysis supports differentiation between helpful and unhelpful aspects of the key mechanisms of change from patients perspective. In the client’s view, the strongest categories comprised relationship factors and therapist variables. Conclusions: Results emphasize the importance of a strong therapeutic alliance in the treatment of patients with BPD from patients perspective, but not consistently for the assessed outcomes. The alliance was experienced and formed mainly by the therapist’s “soft skills” such as empathy, self-disclosure and understanding. The therapist’s ability to attune to the client’s needs implied the use of a wide range of DBT-specific skills.
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Geburtshilfliche Vorbelastung – ein Thema für die stationäre Psychotherapie?Treppesch, Kerstin Iris 02 June 2014 (has links)
Diese Studie soll klären, ob und inwieweit zurückliegende Schwangerschaftsverluste und -abbrüche für eine stationäre Psychotherapie relevant sind. Aufbauend auf zwei Vorstudien wurden in die retrospektive, querschnittliche Hauptstudie 440 Patientinnen einer psychosomatischen Klinik und 585 Frauen aus der Allgemeinbevölkerung (AB) einbezogen. Die geburtshilfliche Anamnese und alle psychologischen Parameter wurden mittels standardisierter Fragebögen erhoben und deskriptiv sowie parametrisch ausgewertet. Sowohl in der AB als auch in der stationären Psychosomatik wiesen 26% der Teilnehmerinnen eine geburtshilfliche Vorbelastung(geb VB) auf, welche im Mittel 20 Jahre zurückliegt. 11% der betroffenen Frauen aus der AB und 31% der Betroffenen in der stationären Psychosomatik nehmen eine anhaltende psychische Belastung durch die geb VB wahr. Trotz der subjektiv anhaltenden psychischen Belastung bei 31% der betroffenen Patientinnen unterscheiden sich diese hinsichtlich ihres aktuellen psychischen Befindens nicht von Patientinnen ohne geb VB. Unterschiede bestehen hingegen zwischen betroffenen stationär psychosomatischen Patientinnen und ebenfalls betroffenen Frauen aus der AB: Bei Patientinnen in der stationären Psychosomatik sind dysfunktionale Verarbeitungsmuster und Trauerreaktionen stärker ausgeprägt. Regressionsanalysen an der Gruppe der Patientinnen mit geb VB in der stationären Psychosomatik zeigen, dass eine Attribution zurückliegender Schwangerschaftsverluste auf „Merkmale der eigenen Person“ mit einem schlechteren Allgemeinbefinden einhergeht. Auch das Ausmaß posttraumatischer Symptome lässt sich teilweise durch Attributionsmuster und Verarbeitungsstrategien erklären. Obwohl aufgrund des Studiendesigns keine kausalen Schlüsse gezogen werden können, liefern die Ergebnisse wichtige Hinweise auf Häufigkeiten von geb VB bei Patientinnen in der stationären Psychosomatik, auf mögliche psychische Beeinträchtigungen und entsprechende Ansatzpunkte in der Psychotherapie. / The aim of this study is to explore whether and to what extent earlier pregnancy losses and abortions are relevant for inpatient psychotherapy. Based on two preliminary studies, data of 440 inpatients of a psychosomatic hospital and 585 women from the general population were included in the retrospective, cross-sectional main study. Both the obstetric history as well as psychological parameters were collected using standardized questionnaires and evaluated by descriptive and parametric statistic methods. In both groups (general population and psychosomatic inpatients) 26% of the participants reported a negative obstetric history, dating back an average of 20 years. Of these women, 11% from the general population and 31% of psychosomatic inpatients perceive an ongoing psychological strain because of their negative obstetric experience. Despite the subjective persistent psychological strain in 31% of the affected inpatients, they do not differ from inpatients without negative obstetric history in terms of their current mental condition. However, there are differences between psychosomatic inpatients with a negative obstetric history and affected women from the general population: Dysfunctional coping patterns and grief reactions are more pronounced with women in inpatient psychosomatic treatment. Regression analyses regarding psychosomatic inpatients with a negative obstetric history show that attributing past pregnancy losses to “personal characteristics” results in poorer general health. The extent of post-traumatic symptoms can also be explained partly by attributional patterns and coping styles. Although due to the study''s design, no causal conclusions can be drawn, the results provide important information on the incidence of negative obstetric history of inpatients in psychosomatic treatment, on possible psychological impairments and on suitable approaches in psychotherapy.
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