A redistribuição e ativação elétrica dos dopantes tipo n (As e Sb) e tipo p (Ga e In) em Si com excesso de vacâncias foram analisadas. As vacâncias foram geradas por implantação iônica de altas doses de oxigênio ou nitrogênio em alta temperatura, de acordo com procedimentos já estudados. Em seguida foram implantados os dopantes com dose de 5x1014 cm-2 a 20 keV na região rica em vacâncias. Dopagens idênticas foram realizadas em amostras de Si sem vacâncias e em SIMOX. Em seguida foram feitos recozimentos a 1000ºC por 10 s ou 15 min. Os perfis atômicos dos dopantes foram medidos com Medium Energy Ion Scattering e os perfis dos dopantes ativados, com Hall diferencial. A redistribuição e as propriedades elétricas de cada um dos dopantes no Si sem vacâncias foram bastante similares às observadas no SIMOX, porém várias diferenças foram observadas em relação às amostras com excesso de vacâncias. As vacâncias reduziram a ativação elétrica do As e do Sb, mas proporcionaram maior estabilidade da ativação após recozimentos longos. A redistribuição destes dopantes foi infuenciada pelo íon usado na geração das vacâncias, ou seja, nitrogênio ou oxigênio. O oxigênio proporcionou maior dose retida de As e o nitrogênio, maior dose retida de Sb. Já para o Ga e o In, as vacâncias tiveram papel fundamental na sua redistribuição, diminuindo a difusão para fora das amostras e garantindo maior dose retida. A ativação elétrica do Ga e especialmente a do In foram baixas, onde observamos forte influência do íon pré-implantado, principalmente o oxigênio. / The redistribution and electrical activation of n type (As and Sb) and p type (Ga and In) dopants in Si with excess vacancy concentration were analyzed. The vacancies were formed by high dose ion implantation of oxygen or nitrogen at high temperature, following previously studied procedures. Dopants were implanted to a dose of 5x1014 cm-2 at 20 keV in the vacancy rich regions of the samples. Identical doping implantations were performed in bulk Si and SIMOX. Samples were then submitted to thermal annealing at 1000ºC for 10 s or 15 min. The dopants atomic profiles were obtained by Medium Energy Ion Scattering and the active dopant profiles, by differential Hall measurements. The redistribution and the electrical properties of each dopant in bulk Si were similar to those observed in SIMOX, but several differences were observed in the vacancy-rich samples. Vacancies reduced the electrical activation of As and Sb, although the activation was maintained stable after long annealing times. The redistribution of these dopants was, otherwise, dominated by the ion used in the vacancy generation, i.e., nitrogen or oxygen. The presence of oxygen resulted in larger As retained dose, while the presence of nitrogen, in larger Sb retained dose. Regarding the p type dopants, Ga and In, the vacancies played an important role in their redistribution, reducing their out-diffusion and allowing larger retained doses. Ga and especially In electrical activation was low, where strong influence of the pre-implanted ions was observed, especially oxygen.

Die vorliegende Dissertation hat die Leerstandsrisiko-Bewertung bei einer Wohnanlagen-Sanierung zum Gegenstand. Ausgangspunkt dieser stellt die Situation auf dem Mietwohnungsmarkt in Ostdeutschland dar, der sich nach dem Ende der 90er Jahre stark verändert hat. Die neue Situation brachte ein Problem mit sich, mit dem die Wohnungsbau-Unternehmen früher kaum gerechnet haben- den Leerstand. Wird unter diesen Leerstandsbedingungen saniert, laufen die Wohnungsbau-Unternehmen die Gefahr, ihren sanierten Bestand nicht vollständig zu vermieten. Daraus resultieren etliche Probleme, die die Existenz derer aufgrund nicht eingenommener Mieten und teuerer Sanierungskosten gefährden. Um solche unwirtschaftliche Gegebenheiten zu vermeiden, ist es bei einer Wohnanlagen-Sanierung notwendig zu ermitteln, mit welchem Umfang das Leerstandsrisiko verknüpft ist und wie dem Mietausfall entgegenzuwirken ist. Auf dieser Basis liefert die Dissertation wichtige Hinweise, wie die Wohnungsbau-Unternehmen passende Sanierungsstrategien ausrichten können, um dieses ernsthafte Problem unter bestimmten Gegebenheiten zu lösen.

In recent years, the nitrogen-vacancy (NV) center has emerged as a promising magnetic sensor capable of measuring magnetic fields with high sensitivity and spatial resolution under ambient conditions. This combination of characteristics allows NV magnetometers to probe magnetic structures and systems that were previously inaccessible with alternative magnetic sensing technologies. This dissertation presents and discusses a number of the initial efforts to demonstrate and improve NV magnetometry. In particular, a wide-field CCD based NV magnetic field imager capable of micron-scale spatial resolution is demonstrated; and magnetic field alignment, preferential NV orientation, and multipulse dynamical decoupling techniques are explored for enhancing magnetic sensitivity. The further application of dynamical decoupling control sequences as a spectral probe to extract information about the dynamics of the NV spin environment is also discussed; such information may be useful for determining optimal diamond sample parameters for different applications. Finally, several proposed and recently demonstrated applications which take advantage of NV magnetometers' sensitivity and spatial resolution at room temperature are presented, with particular focus on bio-magnetic field imaging. / Engineering and Applied Sciences

Observing and controlling solid state quantum systems is an area of intense research in quantum science today. Such systems offer the natural advantage of being bound into a solid device, eliminating the need for laser cooling and trapping of atoms in free space. These solid state "atoms" can interface directly with photonic channels designed to efficiently couple into larger networks of interacting quantum systems. With all of the tools of semiconductor fabrication technology available, the idea of scalable, chip-based quantum networks is a tantalizing prospect. / Physics

No description available.

Cette thèse présente à la fois des résultats de simulations numériques en plus de ré- sultats expérimentaux obtenus en laboratoire sur le rôle joué par les défauts de structure dans le silicium amorphe. Nos travaux de simulation numérique furent réalisés avec une nouvelle méthode de simulation Monte-Carlo cinétique pour décrire l’évolution tempo- relle de modèles de silicium amorphe endommagés sur plusieurs échelles de temps jus- qu’à une seconde à la température pièce. Ces simulations montrent que les lacunes dans le silicium amorphe sont instables et ne diffusent pas sans être détruites. Nous montrons également que l’évolution d’un modèle de silicium amorphe endommagé par une colli- sion ionique lors d’un recuit peut être divisée en deux phases : la première est dominée exclusivement par la diffusion et la création/destruction de défauts de liaison, alors que la deuxième voit les créations/destructions de liens remplacées par des échanges de liens entre atomes parfaitement coordonnés. Les défauts ont aussi un effet sur la viscosité du silicium amorphe. Afin d’approfondir cette question, nous avons mesuré la viscosité du silicium amorphe et du silicium amorphe hydrogéné sous l’effet d’un faisceau d’ions. Nous montrons que la variation de la viscosité dans les deux matériaux est différente : le silicium amorphe hydrogéné a une viscosité constante en fonction de la fluence des ions alors que le silicium amorphe pur a une viscosité qui augmente de façon linéaire. Pour de faibles fluences, la viscosité du silicium hydrogéné est plus grande que la viscosité sans hydrogène. La présence d’hydrogène diminue également l’amplitude de la variation logarithmique de la contrainte observée lors de la relaxation à la température de la pièce. / This thesis presents the results of both computational and experimental studies on the role of structural defects in amorphous silicon. The computational work was done using a novel kinetic Monte-Carlo method to simulate the time evolution of defective models of amorphous silicon over timescales reaching one second at room temperature. These simulations show that the vacancy in amorphous silicon is unstable and does not diffuse without being annihilated. We also show that the annealing behavior of an ion-damaged model of amorphous silicon can be divided in two phases: the initial one being dom- inated exclusively by the diffusion and rapid creation/annihilation of bond defects, the other one with bond defect creation/annihilation being progressively replaced by bond exchanges from perfectly coordinated atoms. Defects also have an effect on the viscosity amorphous silicon. To explore this further we mesure the radiation-enhanced viscosity of pure and hydrogenated amorphous silicon under the effect an ion-beam. We show the change in viscosity is different, the hydrogenated samples having a constant density while the pure amorphous silicon samples having a viscosity that increases linearly with ion fluence. At low fluence, the viscosity of hydrogenated amorphous silicon is higher than the viscosity of pure amorphous silicon. The presence of hydrogen also reduces the amplitude of the logarithmic stress change observed during annealing at room tempera- ture.

Inconel 738, which is a nickel base superalloy used for hot section components of aircraft and industrial turbines is difficult to fabricate and repair by fusion welding due to its susceptibility to heat affected zone (HAZ) intergranular cracking. Crack-free joining of the difficult-to-weld alloy is currently achieved by using linear friction welding (LFW). Nevertheless, oxidation along the joint during LFW is a major problem. Information about the effect of process parameters on the microstructural evolution of linear friction welded nickel base alloys is very limited. In this work, the effect of forging pressure on the microstructure of linear friction welded Inconel 738 was studied. The results as elucidated in this work showed that increased forging pressure caused strain-induced rapid solidification of metastable liquid, which resulted in complete elimination of deleterious liquid phase oxides in bonded material contrasting the generally accepted view that assumes extrusion of solid state oxides during LFW.

Tyrimo objektas: pradinių klasių mokinių laisvalaikio praleidimo būdai. Tyrimo tikslas: išsiaiškinti pradinių klasių mokinių laisvalaikio praleidimo būdus. Tyrimo uždaviniai: 1. Nustatyti 3 – 4 klasės vaikų laisvalaikio praleidimo būdus. 2. Išsiaiškinti vaikų ir tėvų požiūrį į laisvalaikio svarbą prevencijai. 3. Palyginti vaikų ir tėvų požiūrį į laisvalaikį. Rezultatai ir išvados: 1. Mokinių užimtumui mokykloje skiriamas pakankamai didelis dėmesys, todėl vaikai turi pakankamai įvairių laisvalaikio pasirinkimo formų ir dauguma jų yra tuo patenkinti. Dauguma tėvų kiekvieną dieną, savo vaikams skiria dalį savo laisvo laiko. Mėgstamiausios pradinių klasių mokinių laisvalaikio formos mokykloje – bendrauti su klasės vadovu ir lankyti būrelius. Namuose – žiūrėti televizorių ir žaisti kompiuteriu. Atlikta mokinių anketinės apklausos analizė leidžia teigti, jog laisvalaikis užima svarbią vietą asmenybės gyvenime, suteikia galimybę bendrauti su bendraamžiais, skatina asmens aktyvumą, plėtoja kūrybiškumą, pasitikėjimą ir suteikia galimybę išreikšti save bei tobulėti. 2. Vaikų ir tėvų požiūris į laisvalaikio svarbą prevencijai buvo vienareikšmis – visi (100 proc.) sutiko, kad aktyvus užimtumas padeda vaikams išvengti žalingų įpročių ir nusikalstamos veiklos. 3. Laisvalaikis yra svarbus socializacijos elementas. Laisvai pasirinkta ir laisvu laiku atliekama veikla ugdo vaiko socialinius įgūdžius, plečia akiratį, vysto asmenines savybes, padeda užkirsti kelią nusikalstamumui, su tuo... [toliau žr. visą tekstą] / The object of investigation: the ways of spending free time for children of primary classes. The aim of the research: primary school pupils to find out leisure activities. The objectives of the research: 1. To determine possible leisure activities for children of the 3rd-4th grade. 2. To find out children‘ and parents‘ attitude to leisure importance for prevention. 3. To compare children and parents‘ view to leisure. Results and conclusions: 1. There is enough attention paid towards pupils‘ employment at school this children have a freedom to choose from various forms of leisure activities and most of them are satisfied. Most parents every day, your children are part of your free time. Favorite primary schoolchildren pupils forms of leisure at school – communicate with classes teacher and attending curricular activities. At home – to watch TV and to play with computer. Conducted analysis of pupils survey suppone a conclusion, that leisure takes an important in a lifestyle of the personality, improves the communication with contemporary, promotes personal activity, develop creativity, self confidence and provides an opportunity to express theirselves and to improve. 2. Children‘s and parents attitude to leisure importants for prevention was unambiguous – all (100 percent.) agreed, that activity employment helis pupils to avoid hazardous habbits and crime. 3. Leisure is important element of socialization. Free choice and free-time activities carried out by the child develop... [to full text]

Inconel 738, which is a nickel base superalloy used for hot section components of aircraft and industrial turbines is difficult to fabricate and repair by fusion welding due to its susceptibility to heat affected zone (HAZ) intergranular cracking. Crack-free joining of the difficult-to-weld alloy is currently achieved by using linear friction welding (LFW). Nevertheless, oxidation along the joint during LFW is a major problem. Information about the effect of process parameters on the microstructural evolution of linear friction welded nickel base alloys is very limited. In this work, the effect of forging pressure on the microstructure of linear friction welded Inconel 738 was studied. The results as elucidated in this work showed that increased forging pressure caused strain-induced rapid solidification of metastable liquid, which resulted in complete elimination of deleterious liquid phase oxides in bonded material contrasting the generally accepted view that assumes extrusion of solid state oxides during LFW.

This thesis examines residential relocation process within the Seoul Metropolitan Region (SMR) in the Republic of Korea at both a macro and micro level. The thesis makes theoretical and methodological contributions to residential mobility, housing vacancy chains and location choice behaviour in urban geography. The empirical study specifically focused on the relationship between housing opportunity and residential relocation process in the SMR during the 1990s. In developing countries, large scale suburban land and housing development on the fringe of metropolitan areas is seen as an important issue in the process of rapid urbanization and capital accumulation. This is particularly true of Korea where the population of the capital city, Seoul (SCC) has declined since the introduction of massive scale of new suburban housing developments in the 1990s. This is the first time the SCC’s population has decreased in Korean modern history. However there is still debate about the impact of government proposed suburban new housing construction initiatives on residential relocation within the SMR. In addition there remain uncertainties concerning the impact of large suburban housing development on residential relocation behaviour. To date little evaluation of outcomes of the policies has been undertaken, a deficiency which this research seeks to address. Like other capital cities in the developing world, Seoul (SCC) has undergone significant urban expansion throughout its contemporary history, fuelled by the movement of refugees from North Korea in the period immediately following the end of the Korean War (1953) and by significant rural-to-urban, and later by intra urban movement. The SCC, in particular grew significantly, with the metropolitan area of Seoul soon expanding beyond its borders in a process akin to suburbanisation. The rapid urban growth in the Seoul Metropolitan Region (SMR) was accompanied by a series of urban problems including housing shortages, a decline in housing and urban quality, and the concentration of population in large cities, especially in the SCC. To counter these problems the national government in the Republic of Korea initiated a series of policies. Most prominently among these was a massive scale new housing development program initiated in 1988, aimed at developing large scale new satellite cites in Kyonggi, with the objective of decentralising the SCC’s population and thus alleviating an urban housing shortage. This research focuses on two main issues charactering contemporary housing and land development policies in the SMR. The first relates to government efforts to redirect migration from the capital city, Seoul, to the outlying jurisdictions of Kyonggi and Inchon in an attempt to diffuse the concentration of population in the SCC and to alleviate housing shortages. The second issue concerns the determinants of residential mobility and residential location choice behaviour in the SMR. Mirroring the two issues, two approaches have been used to address these issues: a macro level study of residential relocation and a micro behavioural analysis. At macro level the research attempts to measure the impact of new housing developments on easing urban housing markets in the SMR during the 1990s, notwithstanding the continuous population movement from other regions in the Republic of Korea. The macro investigation addresses the questions: • What are the changes in spatial mobility patterns occurring in the SMR since the introduction of government’s suburban residential developments? • Are the size of housing vacancy chains different by spatial mobility patterns among the three regional housing markets in the SMR? Multi-regional vacancy chain models are used to examine whether vacant housing opportunity spills over into neighbouring regions in the SMR, particularly the city of Seoul. The models focus mainly on the structural determinants of household mobility, such as local new housing construction, household formation, household mobility rate and demolition rate, and their role in creating and absorbing vacant housing opportunities in the three jurisdictions comprising the SMR: Seoul (SCC), Kyonggi and Inchon. The vacancy chain analysis uses a Markov chain model and Leontief input-output model to assess the impact of these structural differentials on household mobility in the multiregional system of the SMR. This macro study provides a structural framework for the subsequent micro behavioural approach to residential mobility occurring in the SMR. The micro behavioural approach investigates the following questions: • What are the socio demographic profiles of people who relocate within the SMR?’ • What are the housing transitions that occur after moving to regions of the SCC in the SMR? • What are the reasons households give for moving within the SMR? This micro approach focuses on the behavioural aspects of residential mobility decision process as influenced by age, marital status, employment status, education level, duration of residence, dwelling size and tenure status. Apart from the mover’s socio demographic profile, the study further investigates longitudinal housing transitions before and after a move by their origin and destination within the SMR, particularly those movers who relocated to suburban rings (Kyonggi/Inchon). However the reasons for movers to choose a particular location vary and they are socio demographically diverse. The research also discusses these behavioural reasons for moving within the SMR.