Due to the thesis embargo no abstract is provided.

L'état de surface est l'un des paramètres les plus importants pour déterminer la biocompatibilité d'un dispositif médical implantable, tout changement à la surface une fois en contact avec les tissus corporels peut avoir un impact sur la réponse biologique (cytotoxicité, inflammation, irritation, thrombose ... etc.). Pendant le stockage, l’exsudation des additifs peut se produire à la surface des polymères et modifier leurs propriétés. Dans cette étude, nous utilisons du polyuréthane à base de cathéter (Pellethane®), en raison de ses nombreuses applications dans le domaine des dispositifs médicaux, pour évaluer l'impact d’exsudation des additifs sur la biocompatibilité. L'impact des traitements de stérilisation et d'oxydation sur le phénomène d’exsudation a été étudié. L'étude a été réalisée sur du polyuréthane utilisé dans la fabrication de cathéters sur lesquels l’exsudation de cristaux d’additifs a déjà été observée. La stérilisation par rayonnements ionisants (bêta, gamma) a été réalisée sur ce matériau et les échantillons ont été soumis à différents types de processus d'oxydation (UV, H2O2 et action des macrophages). La viabilité des cellules endothéliales a été étudiée. Une évaluation préliminaire de l'hémocompatibilité a été réalisée par la mesure de l'hémolyse du sang total, ainsi que par l'adhésion des plaquettes en contact avec les différents échantillons de PU. L'étude de la production pro-inflammatoire d'IL-alpha; et de TNF-alpha; par des macrophages en contact avec des échantillons a également été rapportée. / Surface state is one of the most important parameter determining the biocompatibility of animplantable medical device, any change on the surface once in contact with body tissues canimpact the biological response (Cytotoxicity, inflammation, irritation, thrombosis …etc). During storage, the blooming of additives may occur on the surface of polymers and modify their properties. In this study, we use (Pellethane®) catheter-based polyurethane, because of its many applications in the field of medical devices, to evaluate the impact of additives blooming on the biocompatibility. The impact of sterilizing and oxidation treatments on blooming was studied. The study was realized on polyurethane used in the fabrication of catheters on which the blooming of antioxidant crystals has been previously observed. Sterilization by ionizing radiations (beta, gamma) was performed on this material and samples were submitted to different kinds of oxidation process (UV, H2O2 and macrophages action). Endothelial cells viability was studied. A preliminary haemocompatibility evaluation was performed through the measurement of whole blood hemolysis, as well as platelet adhesion in contact with the different PU samples. The study of the pro-inflammatory IL-alpha; and TNF-alpha; production by macrophages in contact with samplesis also reported.

During this thesis work a coupled thermo-mechanical finite element model (FEM) was builtto simulate hot rolling in the blooming mill at Sandvik Materials Technology (SMT) inSandviken. The blooming mill is the first in a long line of processes that continuously or ingotcast ingots are subjected to before becoming finished products. The aim of this thesis work was twofold. The first was to create a parameterized finiteelement (FE) model of the blooming mill. The commercial FE software package MSCMarc/Mentat was used to create this model and the programing language Python was used toparameterize it. Second, two different pass schedules (A and B) were studied and comparedusing the model. The two pass series were evaluated with focus on their ability to healcentreline porosity, i.e. to close voids in the centre of the ingot. This evaluation was made by studying the hydrostatic stress (σm), the von Mises stress (σeq)and the plastic strain (εp) in the centre of the ingot. From these parameters the stress triaxiality(Tx) and the hydrostatic integration parameter (Gm) were calculated for each pass in bothseries using two different transportation times (30 and 150 s) from the furnace. The relationbetween Gm and an analytical parameter (Δ) was also studied. This parameter is the ratiobetween the mean height of the ingot and the contact length between the rolls and the ingot,which is useful as a rule of thumb to determine the homogeneity or penetration of strain for aspecific pass. The pass series designed with fewer passes (B), many with greater reduction, was shown toachieve better void closure theoretically. It was also shown that a temperature gradient, whichis the result of a longer holding time between the furnace and the blooming mill leads toimproved void closure.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-04-24T19:48:05Z No. of bitstreams: 1 Tiziane Horbach Ravasa.pdf: 194025 bytes, checksum: d1b295c3b498dcadabe914d6f2386941 (MD5) / Made available in DSpace on 2015-04-24T19:48:05Z (GMT). No. of bitstreams: 1 Tiziane Horbach Ravasa.pdf: 194025 bytes, checksum: d1b295c3b498dcadabe914d6f2386941 (MD5) Previous issue date: 2013-01-31 / IRGA - Instituto Rio Grandense do Arroz / Em muitos países o plantio de arroz é a atividade mais importante do país, sendo o principal alimento para mais da metade da população mundial. Em lavouras de arroz com sistema de plantio pré-germinado a água permanente pode ser favorável ao desenvolvimento de diversos grupos de organismos, como no caso de comunidades fitoplanctônicas. Assim, o presente trabalho tem como objetivos avaliar que fatores influenciam no desenvolvimento da biomassa fitoplanctônica em lavouras de arroz irrigado pré-germinado e também, avaliar como as fontes de irrigação podem contribuir para o estabelecimento das florações e seus efeitos sobre a riqueza e diversidade fitoplanctônica em sistemas de arroz pré-germinado. Para isso, foram realizadas coletas de água para análise biológica (densidade, riqueza e diversidade do fitoplâncton) no preparo (enchimento) das quadras, logo após o plantio, e em seis outras ocasiões ao longo do ciclo de cultivo, em três lavouras situadas no município de Viamão/RS. Espera-se que, com este trabalho, as informações geradas possam contribuir com conhecimento especializado visando a mitigação dos impactos do desenvolvimento de algas nestes sistemas, entender os processos que determinam a ocorrência das algas planctônicas nos ambientes estudados e compreender o papel das fontes na determinação das florações e seus efeitos sobre a diversidade da comunidade fitoplanctônica em sistemas de cultivo de arroz irrigado pré-germinado. / In various countries rice planting is the most important activity, therefore being the main source of food for half the world’s population. In rice fields with a pre-germinated planting system the permanent water may be favorable to the developing of various groups of organisms, as in phytoplankton communities. Thus, the following paper has the objective to evaluate the factors that affect the development of phytoplankton biomass irrigated pre-germinated rice fields as well as evaluate how the sources of irrigation can contribute to the establishment of blooming and its effects over the phytoplankton richness and diversity in pre-germinated rice systems. In order to accomplish this, water samples were collected for biological analysis (phytoplankton density, richness and diversity) in the area preparation right after the planting and in six other occasions during the planting cycle, in three fields situated in the county of Viamão/RS. It is expected, with this study, that the information obtained may contribute with specialized knowledge in view of mitigating the impacts of algae development in these systems, understanding of the process determining planktonic algae in the environment under study, and understand the role of sources in determining blooming and its effect over the diversity of the phytoplankton community pre-germinated irrigated rice fields.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20417号 / 農博第2202号 / 新制||農||1047(附属図書館) / 学位論文||H29||N5038(農学部図書室) / 京都大学大学院農学研究科農学専攻 / (主査)教授 田尾 龍太郎, 教授 土井 元章, 教授 北島 宣 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

No description available.

Populations of strongly endangered species Orchis mascula and endangered Dactylorhiza majalis were monitored at Peklo area since 2000. In May 2002, another strongly endangered orchid species Orchis ustulata was discovered. The major increase in counts of O. ustulata towards stable numbers of O. mascula and D. majalis populations was detected during the seven year period of plant monitoring. The aim of this study was to reveal a connection between the climate conditions and orchid vitality, using biometrical plant data gained between 2005 to 2011. In order to evaluate a steady state of investigated area, the extensive phytocoenological sampling was conducted. The obtained data revealed several different loci at the screened grassland, which can be defined with presence of distinctive species. In blooming individuals of O. mascula, March temperature was the most defining factor. Parameters studied (number of leaves and blossoms, size of leaves, lenght of stems and duration of flowering) increased with decreasing March temperature. The blooming proved to be important factor, if a plant was in flower that year or the preceeding year, the number and the size of leaves was larger. The blooming in two subsequent years enhanced this described effect even more. The comparison of blooming individuals of O. ustulata revealed that plants growing in clusters were non flowering but bigger in size. Other positive correlation with investigated parameters had precipitation in December. However, the comparison of all plants showed generally smaller size of cluster forming plants. This overall analysis pointed out the influence of low temperature in October, the plants were smaller in size and amount of sterile individuals rised. All collected data and generated comparisons support earlier findings about influence of temperature and precipitation on the orchid population dynamics.

Approved for public release, distribution is unlimited / The Free Electron Laser has the potential to become a revolutionary weapon system. Deep magazines, low cost-per-shot, pinpoint accuracy, and speed of light delivery give this developing weapon system significant advantages over conventional systems. One limiting factor in high energy laser implementation is thermal blooming, a lensing effect which is caused by the quick heating of the atmosphere, so that the laser beam does not focus on the desired spot, thereby degrading the effectiveness of the laser on target. The use of multiple beam directors focusing on a target from a single platform may mitigate thermal blooming by allowing half of the laser's energy to travel through a given volume of air, so that they only overlap very near the target. Less energy traveling through a given volume of space means less heating, and therefore lessens the effects of thermal blooming. Also, simulations of FEL's were conducted modifying parameters such as the number of undulator periods, electron beam focus, the normalized Rayleigh length, and mirror output coupling, in order to determine optimum design parameters. New parameters for the next proposed FEL were simulated to examine the effect of mirror tilt on laser power and extraction as well. / Lieutenant, United States Navy

Many cyanobacteria are reported to produce the nonprotein amino acid β-N-methylamino-L-alanine (BMAA). Cyanobacteria are extensively distributed in terrestrial and aquatic environments and recently BMAA was detected in temperate aquatic ecosystems, e.g. the Baltic Sea. Little is known about developmental effects of the mixed glutamate receptor agonist BMAA. Brain development requires an optimal level of glutamate receptor activity as the glutamatergic system modulates many vital neurodevelopmental processes. The aim of this thesis was to investigate the developmental neurotoxicity of BMAA, and its interaction with the pigment melanin. Autoradiography was utilized to determine the tissue distribution of 3H-labelled BMAA in experimental animals. Behavioral studies and histological techniques were used to study short and long-term changes in the brain following neonatal exposure to BMAA. Long-term changes in protein expression in the brain was also investigated using matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS). A notable targeting of 3H-BMAA to discrete brain regions e.g. hippocampus and striatum in mouse fetuses and neonates was determined by autoradiography. BMAA treatment of neonatal rats on postnatal days 9–10 induced acute but transient ataxia and hyperactivity. Postnatal exposure to BMAA also gave rise to reduced spatial learning and memory abilities in adulthood. Neonatal rat pups treated with BMAA at 600 mg/kg showed early neuronal cell death in the hippocampus, retrosplenial and cingulate cortices. In adulthood the CA1 region of the hippocampus displayed neuronal loss and astrogliosis. Lower doses of BMAA (50 and 200 mg/kg) caused impairments in learning and memory function without any acute or long-term morphological changes in the brain. The MALDI IMS studies, however, revealed changes in protein expression in the hippocampus and striatum suggesting more subtle effects on neurodevelopmental processes. The studies also showed that BMAA was bound and incorporated in melanin and neuromelanin, suggesting that pigmented tissues such as in the substantia nigra and eye may be sequestering BMAA. In conclusion, the findings in this thesis show that BMAA is a developmental neurotoxin in rodents. The risks posed by BMAA as a potential human neurotoxin merits further consideration, particularly if the proposed biomagnifications in the food chain are confirmed.

Materials intended for disposal of spent nuclear fuel require a particular combination of physical and chemical properties. The driving forces and mechanisms underlying the material’s behavior must be scientifically understood in order to enable modeling at the relevant time- and length-scales. The processes that determine the mechanical behavior of copper canisters and iron inserts, as well as the evolution of their mechanical properties, are strongly dependent on the properties of various defects in the bulk copper and iron alloys. The first part of the present thesis deals with precipitation in the cast iron insert. A nodular cast iron insert will be used as the inner container of the spent nuclear fuel. Precipitation is investigated by computing effective interaction energies for point defect pairs (solute–solute and vacancy–solute) in bcc iron using first-principles calculations. The main considered impurities in the iron matrix include 3sp (Si, P, S) and 3d (Cr, Mn, Ni, Cu) solute elements. By computing interaction energies possibility of formation of different second phase particles such as late blooming phases (LBPs) in the cast iron insert is evaluated. The second part is devoted to the fundamentals of dislocations and their role in plastic deformation of metals. Deformation of single-crystal copper under high strain rates is simulated by employing dislocation dynamics (DD) method to examine the effect of strain rate on mechanical properties as well as dislocation microstructure development. Creep deformation of copper canister at low temperatures is studied. The copper canister will be used in the long-term storage of spent nuclear fuel as the outer shell of the waste package to provide corrosion protection. A glide rate is derived based on the assumption that at low temperatures it is controlled by the climb rate of jogs on the dislocations. Using DD simulation creep deformation of copper at low temperatures is modeled by taking glide but not climb into account. Moreover, effective stresses acting on dislocations are computed using the data extracted from DD simulations. / <p>QC 20170428</p>