Bibliographische Beschreibung und Referat Falko Schlottig In der vorliegenden Arbeit wird die Moeglichkeit der anodischen Festkoerpersynthese in ausgewaehlten annaehernd nichtwaessrigen Systemen gezeigt. Die Synthesen wurden sowohl unter anodischen als auch unter anodischen Plasmabedingungen durchgefuehrt. Die entstehenden heterogenen Konversionsschichten wurden mit verschiedenen festkoerperanalytischen Methoden untersucht. Sie sind sind unter den vorgegebenen Darstellungsbedingungen aus nichtoxidischen und oxidischen Phasen zusammengesetzt. Die durchgefuehrten Untersuchungen beziehen sich hauptsaechlich auf die Synthese im System Dimethylacetamid/ Hexamethylentetramin/ KBF4 an Aluminium unter anodischen Plasmabedingungen und auf die Schichtbildung in Acetonitril an Titan unter anodischen Bedingungen. Die an Titan in Acetonitril synthetisierten Konversionsschichten wurden vorwiegend mit Elektronenbeugung und Photoelektronenspektroskopie untersucht. Die Schicht ist aus nitridischen, carbidischen und oxidischen Phasen aufgebaut. Die Struktur und Zusammensetzung der einzelnen Schichtphasen sind von der Synthesespannung abhaengig. Bei Ueberschreitung eines kritischen Potentials wird das bestehende Schichtsystem durch Plasma- und Pyrolysereaktionen modifiziert. Im System Dimethylacetamid/ Hexamethylentetramin/ KBF4 werden unter anodischen Plasmabedingungen an Aluminium kristalline AlF3 - Schichten gebildet, in die KF-Kristallite eingeschlossen sind. Dabei sind Schichtzusammensetzung und -morphologie von der Konzentration des Elektrolyten abhaengig. Waehrend der Plasmareaktion existiert ein Temperaturgradient in der Schicht. Eine nachfolgende thermische Behandlung der Schichtkomponenten unterhalb der eigentlichen Plasmatemperatur fuehrt zu einer Veraenderung der Schichteigenschaften.

Zur detaillierten Beschreibung des Lastabtragverhaltens textiler Bewehrung im Beton ist es erforderlich, das Penetrationsverhalten der Betonmatrix in die stark heterogene Garnstruktur zu beschreiben. Zur Charakterisierung der Mikrostruktur im Querschnitt wurde eine Bildanalysemethode entwickelt, um die Verbundsituation der einzelnen Filamente quantitativ auswerten zu können. Um eine räumliche Beschreibung der Verbundsituation zu erreichen, wurde die Strategie verfolgt, aus aufeinander folgenden Schichtaufnahmen mittels Rasterelektronenmikroskopie eine räumliche Struktur abzuleiten. Hierzu wurden zum einen die experimentelle Vorgehensweise erarbeitet und zum anderen ein Ansatz für die Zuordnung der Filamente zwischen den einzelnen Querschnitten entwickelt.

The submerged entry nozzle (SEN) has been used to transport the molten steel from tundish to the mould. The main purpose of the SEN usage is both to prevent oxygen and nitrogen pick-up by molten steel and to achieve the desired flow condition in the mould. Therefore, the SEN can be considered as a vital factor for a stable casting process and the steel quality. Furthermore, the steelmaking processes occur at high temperatures around 1873 K so the interaction between the refractory materials of the SEN and molten steel is unavoidable. Therefore, the knowledge of the SEN behaviors during pre-heating and casting is necessary for the design of the steelmaking processes. The internal surfaces of modern SENs are coated with a glass/silicon powder layer to prevent the SEN graphite oxidation during pre-heating. The effects of the interaction between the coating layer and the SEN base refractory materials on clogging were studied in supplement 1. The results of the study indicated the penetration of the formed alkaline-rich glaze into the Alumina/graphite base refractory during pre-heating. More specifically, the alkaline-rich glaze reacts with graphite to form carbon monoxide gas. Thereafter, dissociation of CO at the SEN/molten metal interface takes place. This leads to reoxidation of dissolved REM (Rare Earth Metal), which form the “In Situ” REM oxides at the interface between the SEN and the REM alloyed molten steel. Also, the interaction of the penetrated glaze with alumina in the SEN base refractory materials leads to a formation of a high-viscous alumina-rich glaze during the SEN pre-heating process. This in turn, creates a very uneven surface at the SEN internal surface. The “In Situ” formation of the REM oxides together with the uneven internal surface of the SEN may facilitate the accumulation of the primary inclusions. Supplement 1 revealed the disadvantages of the glass/silicon powder layer. On the other hand the carbon oxidation is a main industrial problem for un-coated Alumina/Graphite Submerged Entry Nozzles (SEN) during pre-heating. This led to the proposal of a new refractory material for the SEN. In supplement 2, the effect of ZrSi2 antioxidant and the coexistence of antioxidant additive and (4B2O3 ·BaO) glass powder on carbon oxidation were investigated at simulated non-isothermal heating conditions in a  controlled atmosphere. Also, the effect of ZrSi2 antioxidant on carbon oxidation was investigated at isothermal temperatures at 1473 K and 1773 K. The specimens’ weight losses and temperatures were plotted versus time and compared to each others. The thickness of the oxide areas were measured and also examined using XRD, FEG-SEM and EDS. The coexistence of 8 wt% ZrSi2 and 15 wt% (4B2O3 ·BaO) glass powder of the total alumina/Graphite base refractory materials, presented the most effective resistance to carbon oxidation. The 121% volume expansion due to the Zircon formation during heating and filling up the open pores by (4B2O3 ·BaO) glaze during green body sintering led to an excellent carbon oxidation resistance. In supplement 3, decarburization behaviors of Al2O3-C, ZrO2-C and MgO-C refractory materials constituting a commercial Submerged Entry Nozzle (SEN), have been investigated in different gas atmosphere consisting of CO2, O2 and Ar. The (CO2/O2) ratio values were kept the same as it is in propane combustion flue gas at Air Fuel Ratio (AFR) values equal to 1.5 and 1 for both Air-fuel and Oxygen-fuel combustions. Laboratory experiments were carried out non-isothermally in the temperature range 873 K to 1473 K at 15 K/min followed by isothermal heating at 1473 K for 60 min. The decarburization ratio (α) values of the three refractory types were determined by measuring the weight losses of the samples. The results showed that the decarburization ratio (α) values of the MgO-C refractory became 3.1 times higher for oxygen-fuel combustion compared to air-fuel combustion both at AFR equal to 1.5 in the temperature range 873 K to 1473 K. The decarburization ratio (α) values for Al2O3-C samples were the same as for the isothermal heating at 1473 K and non-isothermal heating in the temperature range 473  to 1773 K with a 15 K/min heating rate. It substantiates the SEN preheating advantage at higher temperatures for shorter holding times instead of heating at lower temperatures for longer holding times. Jander’s diffusion model was proposed for estimating the decarburization rate of Al2O3-C refractory in the SEN. The activation energy for Al2O3-C samples heated at AFR equal to 1.5, for air-fuel and oxygen-fuel combustions were found to be 84.5 KJ/mol and 95.5 KJ/mol respectively during non-isothermal heating in the temperature range 873 K to 1473 K. / QC 20101008

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La présente thèse examine les liens entre le sommeil, la mémoire épisodique et les rêves. Dans une première étude, nous utilisons les technologies de la réalité virtuelle (RV) en liaison avec un paradigme de privation de sommeil paradoxal et de collecte de rêve en vue d'examiner l'hypothèse que le sommeil paradoxal et le rêve sont impliqués dans la consolidation de la mémoire épisodique. Le sommeil paradoxal a été associé au rappel des aspects spatiaux des éléments émotionnels de la tâche RV. De la même façon, l'incorporation de la tâche RV dans les rêves a été associée au rappel des aspects spatiaux de la tâche. De plus, le rappel des aspects factuels et perceptuels de la mémoire épisodique, formé lors de la tâche VR, a été associé au sommeil aux ondes lentes. Une deuxième étude examine l'hypothèse selon laquelle une fonction possible du rêve pourrait être de créer de nouvelles associations entre les éléments de divers souvenirs épisodiques. Un participant a été réveillé 43 fois lors de l'endormissement pour fournir des rapports détaillés de rêves. Les résultats suggèrent qu'un seul rêve peut comporter, dans un même contexte spatiotemporel, divers éléments appartenant aux multiples souvenirs épisodiques. Une troisième étude aborde la question de la cognition lors du sommeil paradoxal, notamment comment les aspects bizarres des rêves, qui sont formés grâce aux nouvelles combinaisons d'éléments de la mémoire épisodique, sont perçus par le rêveur. Les résultats démontrent une dissociation dans les capacités cognitives en sommeil paradoxal caractérisée par un déficit sélectif dans l'appréciation des éléments bizarres des rêves. Les résultats des quatre études suggèrent que le sommeil aux ondes lentes et le sommeil paradoxal sont différemment impliqués dans le traitement de la mémoire épisodique. Le sommeil aux ondes lentes pourrait être implique dans la consolidation de la mémoire épisodique, et le sommeil paradoxal, par l'entremise du rêve, pourrais avoir le rôle d'introduire de la flexibilité dans ce système mnémonique. / The present dissertation examines relationships between sleep, episodic memory and dreaming. In Articles I and II we use a novel virtual reality (VR) task in conjunction with a rapid eye movement (REM) sleep deprivation (REMD) paradigm and dream sampling to examine the hypothesis that REM sleep and dreaming are involved in the consolidation of episodic memory. REM sleep was associated with the successful recall of the spatial aspects of emotionally charged elements of the VR task. Similarly, dreaming was associated with improved performance on the spatial aspects of the recall task. Recall of the factual and perceptual aspects of episodic memories formed with the VR task was associated with increased slow wave sleep (SWS) during the post-exposure night. Overall, the results suggest that SWS is associated with the perceptual and factual aspects of episodic memories while REM sleep is not, a finding which may relate to observations that REM sleep dreaming is composed of deconstructed fragments of loosely associated episodic memories. Study II examines the hypothesis that a function of dreaming may be to create new associations between previously unrelated memory items. A participant, highly trained in introspection and mentation reporting, was awakened 43 times during theta bursts at sleep onset and provided detailed reports of resulting imagery and associated memory sources. This technique provided evidence that elements of distally related memory sources are brought together in temporal and spatial proximity within a novel context provided by the dream, suggesting a role for dreaming in memory processing. To allow for this possibility, we speculate that dreaming experiences may be functionally equivalent to waking experiences in their ability to induce neural plasticity. Study III addresses an aspect of this functional equivalence by examining if dream bizarreness is incompatible with behavioral and cognitive features associated with waking state experience-driven plasticity, i.e., whether the dreamer can act upon, emote and be motivated towards an element of the dream that is bizarre and that violates basic assumptions of physical reality. The results demonstrate a dissociation in cognitive ability during dreaming characterized by a selective deficiency in appreciating bizarreness in face of a maintained ability for logical thought. This finding thus addresses the problem of the wake-like mind reflecting upon dream bizarreness and suggests that dreaming is a state in which the cognitive aspects associated with synaptic plasticity (attention, emotion and motivation associated with believing a situation to be reality) are present while allowing for the presentation of memory item combinations which may transcend the limits of physical reality. The results of the four studies are discussed in light of how REM and SWS sleep stages are differentially involved in specific aspects of episodic memory (episodic replay vs. episodic novelty) and the possible role that dreaming, as a driver of synaptic plasticity, may have in these relationships.

La littérature suggère que le sommeil paradoxal joue un rôle dans l'intégration associative de la mémoire émotionnelle. De plus, les rêves en sommeil paradoxal, en particulier leur nature bizarre et émotionnelle, semblent refléter cette fonction associative et émotionnelle du sommeil paradoxal. La conséquence des cauchemars fréquents sur ce processus est inconnue, bien que le réveil provoqué par un cauchemar semble interférer avec les fonctions du sommeil paradoxal. Le premier objectif de cette thèse était de reproduire conceptuellement des recherches antérieures démontrant que le sommeil paradoxal permet un accès hyper-associatif à la mémoire. L'utilisation d'une sieste diurne nous a permis d'évaluer les effets du sommeil paradoxal, comparativement au sommeil lent et à l’éveil, sur la performance des participants à une tâche sémantique mesurant « associational breadth » (AB). Les résultats ont montré que seuls les sujets réveillés en sommeil paradoxal ont répondu avec des associations atypiques, ce qui suggère que le sommeil paradoxal est spécifique dans sa capacité à intégrer les traces de la mémoire émotionnelle (article 1). En outre, les rapports de rêve en sommeil paradoxal étaient plus bizarres que ceux en sommeil lent, et plus intenses émotionnellement ; ces attributs semblent refléter la nature associative et émotionnelle du sommeil paradoxal (article 2). Le deuxième objectif de la thèse était de préciser si et comment le traitement de la mémoire émotionnelle en sommeil paradoxal est altéré dans le Trouble de cauchemars fréquents (NM). En utilisant le même protocole, nos résultats ont montré que les participants NM avaient des résultats plus élevés avant une sieste, ce qui correspond aux observations antérieures voulant que les personnes souffrant de cauchemars soient plus créatives. Après le sommeil paradoxal, les deux groupes, NM et CTL, ont montré des changements similaires dans leur accès associatif, avec des résultats AB-négatif plus bas et AB-positif plus grands. Une semaine plus tard, seul les participants NM a maintenu ce changement dans leur réseau sémantique (article 3). Ces résultats suggèrent qu’au fil du temps, les cauchemars peuvent interférer avec l'intégration de la mémoire émotionnelle pendant le sommeil paradoxal. En ce qui concerne l'imagerie, les participants NM avaient plus de bizarrerie et plus d’émotion positive, mais pas négative, dans leurs rêveries (article 4). Ces attributs intensifiés suggèrent à nouveau que les participants NM sont plus imaginatifs et créatifs à l’éveil. Dans l'ensemble, les résultats confirment le rôle du sommeil paradoxal dans l'intégration associative de la mémoire émotionnelle. Cependant, nos résultats concernant le Trouble de cauchemars ne sont pas entièrement en accord avec les théories suggérant que les cauchemars sont dysfonctionnels. Le groupe NM a montré plus d’associativité émotionnelle, de même que plus d'imagerie positive et bizarre à l’éveil. Nous proposons donc une nouvelle théorie de sensibilité environnementale associée au Trouble de cauchemar, suggérant qu'une sensibilité accrue à une gamme de contextes environnementaux sous-tendrait les symptômes uniques et la richesse imaginative observés chez les personnes souffrant de cauchemars fréquents. Bien que davantage de recherches doivent être faites, il est possible que ces personnes puissent bénéficier e milieux favorables, et qu’elles puissent avoir un avantage adaptatif à l'égard de l'expression créative, ce qui est particulièrement pertinent lorsque l'on considère leur pronostic et les différents types de traitements. / Existing literature suggests that REM sleep plays a role in the associative integration of emotional memory, and that attributes of dreams during REM sleep, particularly their bizarre and emotional nature, either reflect or even influence this associative and emotional function. The consequence of frequent nightmares on this process is unknown, although, the experience of a nightmare suggests an associative restriction imposed by intense negative emotion, consistent with research showing that negative affect tends to restrict cognitive flexibility in wake. This is consistent with existing theories of nightmare function, largely purporting that nightmares reflect temporary failures in emotion regulation. The first objective of the thesis was to conceptually replicate prior research portraying REM sleep as enabling increased associative access to emotional memory. The use of a daytime nap allowed us to assess the effects of REM sleep, compared to both NREM sleep and waking, on participant performance on a novel task measuring Associational Breadth (AB). Results showed that only those subjects awakened from REM sleep responded with atypical emotional word associations, suggesting that REM is specific in its capacity to broadly integrate emotional memory traces (article 1). Further, REM dream reports were more bizarre than both NREM dreams and waking daydreams, and more emotionally intense than NREM dreams; these attributes are thought to reflect the hyper-associative and emotional nature of REM sleep (article 2). The second objective was to clarify whether and how REM sleep-dependent emotional memory processing is altered in frequent nightmares sufferers. Using a similar nap protocol, our results showed that NM participants had higher baseline AB in response to emotional cue-words, contrary to predictions, but nonetheless corresponding with anecdotal reports of heightened creativity. Following REM sleep, both NM and CTL groups showed similar changes in associative access to emotional cue-words, with negative AB being restricted and positive AB being broadened; one week later, the NM group alone maintained this altered pattern of emotional semantic access (article 3). This finding suggests that, over time, nightmares may interfere with REM sleep-dependent emotional memory integration. Regarding imagery, the NM participants had heightened bizarreness, and positive, but not negative, imagery in their daydreams, but not their dreams (article 4), mirroring our AB finding that the NM group had significantly higher emotional associativity in wake, although patterns of associativity following a REM sleep nap did not differ between groups. Overall, findings support a role of REM sleep in the associative integration of emotional memory. However, our findings regarding nightmare sufferers are not entirely consistent with views that nightmares are associated with dysfunctional emotional memory processing. Although they did show a prolonged priming effect suggestive of inadequate emotion regulation, they also showed heightened semantic associativity and vivid positive imagery in wake. We therefore propose a novel Environmental Sensitivity framework for the study of nightmare sufferers, claiming that an increased sensitivity to a range of environmental contexts, not only negative contexts, underlies the unique symptoms and imaginative richness seen in frequent nightmare sufferers. Although further empirical research exploring potentially adaptive traits or sensitivity to positive contexts in nightmare sufferers is needed, the possibility that these individuals may benefit especially from supportive environments, and may have heightened creativity and semantic associativity, is particularly relevant when considering prognosis and treatment approaches.

Made available in DSpace on 2016-04-26T20:27:27Z (GMT). No. of bitstreams: 1 Marcus Vinicius dos Santos Andrade.pdf: 589135 bytes, checksum: 2a90e100de6b42f0a9d4782227249afa (MD5) Previous issue date: 2008-06-11 / The reason for this work arose at institute now renewed in the Brazilian civil order: surface right. The objective was studying it in all the implication. Researching its structure and understanding its meaning. This study had and has justification in social and economical values demanding adequate juridical laws. Considering that everything which goes over the land as plantations and buildings characterize tenancy and building lease its importance has to be recognized to implement social policy, in the city or in the country. Firstly, the methodology used was based on the genesis institute from its history until now turning into a Brazilian law. Secondly, researching the changes of the meanings of property considered since the unitary individualism up to the transformation of autonomous dominium of the earth and tenancy and building lease. To achieve the points the tenancy and building lease was studied as a thing (chapter 1 phenomenology); historic unpredictable changes up to now in Brazil, since Brazil´s colonization (chapters 2 and 3 about the evolution of the judicial thoughts in Portugal and Brazil until 1916) following came the studies of many and different laws (chapter 4 comparing laws and chapter 5 surface laws in Brazil) the research was on top of the Branzilian law putting the tenancy and the building lease among the right in rem analyzing the elements, objects, structure, documents, the content of permission, alienate and extinction ending with law protection (chapter 6 and 13). Finally the way of using the institute in urban and agricultural laws (chapter 14- urban tenancy, 15- rural tenancy and 16 property social function) / A motivação, deste trabalho, se inspirou em instituto, agora, renovado no ordenamento civil brasileiro: o direito de superfície. O objetivo era o de estudá-lo em todas suas implicações, pesquisando sua estrutura, buscando apreender seu significado. Essa reflexão tinha e tem justificativa no valor social e econômico que projeta, a exigir tratamento jurídico adequado. Considerando-se que compreende o que se eleva do solo, como edificações e plantações, de convir sua importância para consecução de políticas sociais, na cidade e no campo. Para tanto, priorizou-se metodologia, por primeiro, baseada na gênese do instituto, informada por sua história, até que cristalizado na legislação brasileira. Em segundo, a investigação dirigiu-se às alternâncias conceituais da propriedade, considerada desde o individualismo unitário até o desdobramento em domínios autônomos: do solo e da superfície. Para a consecução desses objetivos, de início pesquisou-se a superfície como coisa (capítulo 1 Fenomenologia) e, depois, suas vicissitudes históricas até a atualidade e com repercussão no Brasil, da Colônia até os últimos diplomas legislativos (capítulos 2 e 3, respectivamente Histórico e evolução do pensamento jurídico e a superfície em Portugal e no Brasil: na Colônia, no Império e nos primeiros anos da República, até 1916). Em seguida, passou-se ao estudo de vários textos legislativos (capítulo 4: Elementos legislativos de comparação e capítulo 5: Legislação sobre direito de superfície no Brasil). Na seqüência, a perquirição centralizou-se no direito positivo brasileiro, situando a superfície entre os direitos reais, com a análise de seus elementos, objeto, estrutura, modos de constituição, conteúdo da concessão, alienação e extinção, terminando pela tutela judicial (capítulos 6 a 13). Por derradeiro, foi examinada a aplicabilidade técnica do instituto nas legislações sobre direito urbanístico e sobre direito agrário (capítulos 14, 15 e 16, respectivamente, superfície urbana, superfície rural e função social da propriedade e do direito real da superfície)

The basal ganglia (BG) are a group of brain nuclei situated deep in the cerebral hemispheres. While BG were primarily associated with motor functions, in recent years there has been an increasing evidence that BG are also significantly involved in a wide range of non-motor functions. This work focused on some of the non-motor symptoms associated with two typical basal ganglia disorders: Parkinson's disease (PD) and Huntington's disease (HD). The first study concerned spatial navigation impairment in patients with HD. Their spatial navigation skills were tested using the Blue Velvet Arena, technique evaluating spatial navigation in real space, capable to selectively differentiate between two components of spatial navigation - allocentric (environment-oriented) and egocentric (self-oriented). Allocentric navigation is linked to hippocampal function, whereas egocentric navigation is usually associated with striatum, a structure predominantly affected in HD. We found that spatial navigation is not significantly affected in the early stages of HD and that in more advanced stages, when spatial navigation is already impaired, there is no significant difference between allocentric and egocentric navigation impairment. We speculate that the striatal involvement does not contribute to the impairment of the...

[pt] No final dos anos 1960, os projetos arquitetônicos em grandes escalas foram desacreditados no Ocidente por estarem associados à presença dos Poderes vigentes. Influenciados pelos ideais de Maio de 1968, os arquitetos ocidentais passaram a procurar modelos alternativos, baseados na linguagem histórica. Eles buscavam com isso alcançar a autonomia da forma arquitetônica, esvaziando-a do suposto conteúdo ideológico, que estaria aderido às formas abstratas modernas. No entanto, o enfoque pós-moderno nos elementos formais do objeto arquitetônico e do espaço urbano implicava no abandono da questão urbanística na escala metropolitana. Esta escala espacial seria marcada pela perda das referências às estruturas formais orgânicas. No Japão, a pesquisa moderna em grandes escalas não foi interrompida, oferecendo um amplo instrumental para a questão urbanística contemporânea. Esta dissertação verifica como os arquitetos Fumihiko Maki e Rem Koolhaas propõem a retomada e a revisão do urbanismo moderno metropolitano. Eles partem do pressuposto de que a Forma arquitetônica seria vazia de significados intrínsecos. A apropriação por parte dos Poderes e, também, por parte das pessoas imprimiria à arquitetura significados, retirando dos arquitetos a responsabilidade sobre a totalidade do projeto e devolvendo-lhes a legitimidade da disciplina. Esta pesquisa percorre os caminhos seguidos por esses arquitetos a partir de suas referências orientais e ocidentais, mostrando como, em diversos momentos, os conceitos arquitetônicos dos dois mundos convergem, apontando a persistência do pensamento moderno. / [en] By the end of the 1960s, large-scale architectural projects were discredited in West because they were associated with the established Power. Influenced by the ideals of May 1968, architects began searching alternative models based on the Historical language. They wanted to reach the autonomy of the architectural form by releasing it from their supposed ideological content, which was adhered to the abstract modern forms. Nevertheless, the post-modern approach, which was based on formal elements of the architectonical object and of the urban space, implied in the relinquishment of the metropolitan-scale. This urban-scale would be characterized by the references loss of organic formal structures. In Japan, modern research on large-scales was not interrupted, offering an important arsenal to the questions of contemporary urbanism. This dissertation verifies how the architects Fumihiko Maki and Rem Koolhaas propose the retaking and revision of modern metropolitan urbanism. They presuppose that architectonical Form is devoid of intrinsic meaning. Its appropriation by Power and also by people gives it meaning, removing architects responsibility on the totality of the project and giving them back the legitimacy of the discipline. This research follows the paths opened by these two architects through their Eastern and Western references, revealing the many instances in which architectonical concepts of both worlds converge, aiming to the persistence of modern thought.

The presence of non-metallic inclusions (NMIs) have critical effects on both the mechanical properties and machinability of steels. In the present thesis, one focus is to study the characteristics of deformed sulfides (MnS) for a stainless steel (3R65) and a tool steel (42CrMo4). Three groups of MnS inclusions were detected in the samples taken after deformation of the steel: i) type RS (sulfides with a Rod-like geometry), ii) type PS (sulphides with a plate-like geometry) and iii) type OS (oxy-sulfides). Here, the elongated inclusions present in both stainless and tool steels were studied more in detail using SEM to determine the tendency for the inclusions to break.  The results showed that three types of elongated MnS inclusions could be identified, namely UU, UB and BB. Here, ‘U’ represents the unbroken edge(s) of inclusion and ‘B’ represents the broken edge(s) of an inclusion. The presence of these three types of inclusions in samples collected both before and after a heat treatment was studied and the results showed that the heat treatment had a very small effect on the morphologies of the elongated MnS inclusions for both stainless steels (containing <0.1 mass % C) and tool steels (containing 0.42 mass % C).  In the second part of the thesis, the characteristics of chips after machining of a 157REM Ce-treated steel and a 157C reference steel was studied. Furthermore, the effect of the NMIs on the chip breakability during machining was determined. The results show that a Ce modification of a 157C steel transforms the NMIs from large size elongated inclusions to small size inclusion with a spherical shape. This leads to an improved machinability of 157C steels. In addition, a newly developed weight distribution of chips (WDC) method, based on the chip weight measurements, was used to determine the tendencies for breaking of chips. The results of this investigation showed that the chips that were obtained from the machining of 157C and the 157REM steels could be classified into the following three types: i) type I chips (with a geometry containing one arc) and having a weight of less than 0.08 g, ii) type II chips (with a geometry containing two arcs) and having weights between 0.08 g and 0.15 g, and iii) type III chips (with a geometry containing three or more arcs) and having weights larger than 0.15 g. From industrial experience, it is known that a high amount of small type I chips will lead to a good chip breakability. The results from the machining test show that the fraction of type I chips from machining of the 157REM steel (65 %) is smaller than from machining of the 157C reference steel (80 %) when using a lower feed rate of 0.4 mm/rev. However, when using a higher feed rate of 0.5 mm/rev, 40 % of the chips belong to type I small chips for the 157REM steel and 14 % for the 157C steel. Based on the conditions used in this study and the obtained results, the following is clear in order to reach the best machinability: i) it is most advantageous to use the 157C steel when using a lower feed rate of 0.4 mm/rev and ii) it is most advantageous to use the 157REM steel when using a higher feed rate of 0.5 mm/rev. / Närvaron av icke-metalliska inneslutningar (NMIs) har en betydande påverkan både med avseende på mekaniska egenskaper såväl som skärbarhetsförmågan hos stål. I denna avhandling är ett fokus att studera deformerade sulfider (MnS)  i ett rostfritt stål (3R65) och ett verktygsstål (42CrMo4). Tre grupper av MnS inneslutningar återfanns i stålproverna, som togs efter deformation av stålet: i) RS (sulfider som har en cylindrisk geometri), ii) PS (sulfider som har en platt geometri) och iii) OS (oxy-sulfider). Dessutom så studerades utdragna inneslutningar mer i detalj med användande av SEM undersökningar i syfte att studera tendensen till att dessa inneslutningar bröts sönder. Resultaten visade att tre typer av utdragna inneslutningar kunde identifieras, nämligen UU, UB och BB. Här representerar ‘U’ en ände av en inneslutning som inte brutits sönder och ‘B’ representerar en ände av en inneslutning som brutits sönder. Närvaron av dessa tre typer av utdragna inneslutningar studerades i prover som togs både före och efter en värmebehandling, men resultaten visade att en värmebehandling hade en mycket liten påverkan på morfologin hos de utdragna MnS inneslutningarna för både rostfria stål (innehållande <0.1 mass % C) och verktygsstål (innehållande 0.42 mass % C).  I den andra delen av avhandlingen så studerades karakteristiken hos spånor som bildats efter skärande bearbetning av ett 157REM (Ce-behandlat) modifierat stål och ett 157C referensstål som inte modifierats. Dessutom så studerades inverkan av icke-metalliska inneslutningar på spånbrytningen under den skärande bearbetningen. Resultaten visar att en Ce-modifiering av stålet omvandlar inneslutningarna från stora och utdragna geometrier till små inneslutningar med en sfärisk geometri. Detta leder till en ökad skärbarhet hos 157C stål. Spånbrytbarheten bestämdes också med användande av en nyutvecklad metod (WDC metoden) som baseras sig på att bestämma vikten av spånor. Resultaten av denna utvärdering visade att spånorna som erhölls från bearbetning av 157C och 157REM stål kunde klassificeras enligt följande tre typer: i) typ I spånor (en geometri som består av en bågform) som har en vikt som är mindre än 0.08 g, ii) typ II spånor (en geometri som består av två bågformar) som har en mellan 0.08 g och 0.15 g och iii) typ III spånor (en geometri som består av tre eller fler bågformar) som har en vikt som är större än 0.15 g. Baserat på industriell erfarenhet så är det känt att en stor mängd av små typ I spånor är kopplad till en bra spånbrytbarhet. Resultaten från skärbarhetstesterna visar att andelen typ I spånor från bearbetning av ett 157REM stål (65 %) är mindre än vid bearbetning av ett 157C referens stål (80 %), när en lägre matningshastighet av 0.4 mm/rev används. Däremot så visar resultaten att om en högre matningshastighet av 0.5 mm/rev används vid bearbetning, så är andelen typ I spånor 40 % för 157REM stålet och 14 % för 157C referensstålet. I syfte att erhålla bästa möjliga skärbarhet så är det fördelaktigt att använda ett 157C referensstål för den lägre matningshastigheten av 0.4 mm/rev, men att använda ett 157REM stål för en högre matningshastighet av 0.5 mm/rev.