Os experimentos com refletores nucleares de material pesado foram realizados no reator IPEN/MB-01 utilizando-se chapas de aço inoxidável, de aço carbono ou de níquel, num total de 32 chapas de cada material, inseridas adequadamente na face oeste do núcleo do reator. As chapas têm cerca de 3 mm de espessura. A largura e comprimento axial foram suficientes para cobrir todo o núcleo ativo do reator. Tais experimentos foram realizados com cada tipo de material refletor individualmente. Para cada etapa de colocação de chapas foram efetuadas medidas da reatividade devido à inserção destas no núcleo; bem como da posição crítica das barras de controle com BC1 e BC2 igualmente retiradas. Pôde ser observado que o aumento da absorção de nêutrons e consequente diminuição da moderação de nêutrons dominaram toda a física do problema quando foram inseridas poucas chapas de material refletor (cerca de 5 chapas para o aço inoxidável e aço carbono, e 3 chapas no caso do níquel). Na sequência, a reflexão de nêutrons tornou-se importante superando a absorção neutrônica; a reatividade aumentou até ultrapassar a situação sem chapa (excesso de reatividade zero) obtendo-se um acréscimo (ganho líquido) de reatividade com as 32 chapas inseridas (cerca de 162 pcm no caso do aço inoxidável, 37 pcm para o aço carbono e 295 pcm para o níquel). Portanto, observou-se que o núcleo refletido tornou-se mais reativo do que o núcleo sem material refletor. Resultados experimentais inéditos de medidas de reatividade foram obtidos com refletores de níquel. No que concerne a esse tipo de experimento não existe experimento similar na literatura internacional ao realizado no reator IPEN/MB-01. A análise teórica empregando o MCNP-5 e a biblioteca de dados nucleares ENDF/B-VII.0 evidenciou os aspectos físicos de absorção e reflexão de nêutrons nas chapas de material refletor considerados; entretanto apresentou uma discrepância quando a reflexão de nêutrons rápidos domina o fenômeno físico do transporte de nêutrons. Essas tendências foram encontradas independentemente do tipo de refletor pesado empregado nos experimentos. / Experiments with heavy-material nuclear reflectors were performed in the IPEN / MB-01 reactor using stainless steel, carbon steel or nickel plates, in a total of 32 plates of each material, properly inserted in the western face of the reactor core. The plates are about 3 mm thick. The axial width and length were sufficient to cover the entire active core of the reactor. Such experiments were performed with each type of reflective material individually. For each step of placement of plates were made measures of reactivity due to the insertion of these in the core; as well as the critical position of the BC1 and BC2 control rods also removed. It could be observed that the increase in neutron absorption and consequent decrease in neutron moderation dominated the whole physics of the problem when a few reflective material plates were inserted (about 5 plates for stainless steel and carbon steel and 3 plates for nickel). Subsequently, neutron reflection has become important overcoming neutron absorption; the reactivity increased until it exceeded the situation without plate (excess of zero reactivity) obtaining an increase (net gain) of reactivity with 32 inserts inserted (about 162 pcm in the case of stainless steel, 37 pcm for carbon steel and 295 pcm for nickel). Therefore, it was observed that the reflected core became more reactive than the core without reflective material. Unpublished experimental results of reactivity measurements were obtained with nickel reflectors. As for this type of experiment, there is no similar experiment in the international literature compared to the IPEN/MB-01 reactor. The theoretical analysis using the MCNP-5 together with nuclear data library ENDF/B-VII.0 evidenced the physical aspects of neutron absorption and reflection in the reflective material plates considered; however, it presented a discrepancy when the reflection of fast neutrons dominates the physical phenomenon of the transport of neutrons. These trends were found independently of the type of the heavy reflector employed in the experiments.

No description available.

In dieser retrospektiven Pilotstudie zum Einsatz von rekombinatem, aktivierten Faktor VII bei Frühgeborenen (Schwangerschaftswoche < 32, Geburtsgewicht < 1750 g) mit intraventrikulären Hirnblutungen wurden anhand sonografischer Untersuchungen der Blutungsprogress sowie die Nebenwirkungen der Therapie im Vergleich zur Standarttherapie mit Fresh Frozen Plasma untersucht. Die Auswertung erfolgte in zwei Gruppen: innerhalb des Gesamtkollektives und innerhalb der Matching-Gruppe. Es zeigte sich in beiden Auswertungsgruppen ein signifikant geringerer Blutungsprogress in der Therapiegruppe. Außerdem konnte ein früherer Blutungsstopp in der Therapiegruppe nachgewiesen werden. Ein erhöhtes Nebenwirkungspotential von rekombinantem, aktivierten Faktor VII war in diesem Patientenkollektiv nicht eruierbar. Weiterführende prospektive, randomisierte, multizentische Studien zur Evaluation dieses vielversprechenden Therapieansatzes werden empfohlen.

Cette thèse porte sur l’étude des différentes formes de gouvernement dans les villes du Centre-Nord qui furent mises en œuvre dans l’Italie du début du XIVe siècle. La transformation institutionnelle des communes est mise en relation avec la redécouverte de l’intérêt pour l’organisation politique de l’ensemble du Centre-Nord de l’Italie, en stricte relation avec le regnum Italicum.La première partie de la thèse est consacrée à la reconstruction du voyage en Italie d’Henri VII. Toutefois, comme la politique impériale se heurta rapidement à celle des villes italiennes, il a été nécessaire d’analyser comment les communes réagirent face à cette descente et à la mise en œuvre de ce programme politique. Puis, l’étude examine les politiques adoptées par Henri VII au cours de la seconde phase de son voyage en Italie, au temps des tentatives pour réprimer les diverses révoltes qui éclatent dans les communes touchées par les réformes impériales. La deuxième partie de la thèse est dédiée à l’étude des influences du projet d’Henri VII sur les pouvoirs qui cherchèrent à redonner une vie politique au royaume d’Italie, et ce durant cette période qui se situe entre la mort d’Henri VII et la généralisation des formes de gouvernement seigneurial. L’analyse porte notamment sur les tentatives de défense des communes face à la papauté et à la monarchie angevine. Afin de tracer un parallèle avec la Romfahrt impériale, une section de la thèse a été consacrée au voyage en Italie de Jean de Bohême.En conclusion, l’ascension d’Azzone Visconti inaugure un nouveau système de gouvernement communal, en absence d’un projet de constitution d’un royaume de Lombardie. / This thesis tackles the government of central and northern Italian cities at the beginning of the fourteenth century through a perspective which until now has been overlooked by historiography. In this study, the institutional transformation of the cities will be interrelated with the renewal in the interest for the reorganization of central and northern Italy on a regional scale, in connection with the realities of the regnum italicum. Thus the discussion is developed on different planes of analysis – urban and regional – in which the intense activity exercised by royal powers on urban institutions has been used as a common thread. The first part of the thesis reconstructs Henry VII’s voyage in Italy, in order to bring to light the imperial program for the reform of the kingdom. The imperial policies did not follow a linear path, as these were soon complicated by the unavoidable confrontation with the cities. This discussion is followed by an analysis of the policies adopted by the emperor during the second phase of his voyage in Italy, when he intervened to thwart the revolts borne in opposition to his urban reforms by adjusting his lines of action both on a juridical and on an institutional level. The second part of the dissertation is aimed at finding traces of Henry VII’s project in the experimentations of other royal powers which in the two decades that followed intended to give political and administrative substance to the kingdom of Italy. It has thus been possible to continue the discussion on the civic action in defense of autonomy in connection to the Papacy and the Angevin monarchy. In addition to this, the voyage of John of Bohemia in Italy, which represented a new concrete attempt to impose a royal power over the area, has been taken under examination as a parallelism to the imperial Romfahrt. The study closes with the rise of Azzone Visconti a political experience wich ushered a new approach in the government of cities, in absence of a project for a kingdom in Lombardy.

Master of Science / Department of Statistics / Weixing Song / A robust estimation procedure for parametric regression models is proposed in the paper by assuming the error terms follow a Pearson type VII distribution. The estimation procedure is implemented by an EM algorithm based on the fact that the Pearson type VII distributions are a scale mixture of a normal distribution and a Gamma distribution. A trimmed version of proposed procedure is also discussed in this paper, which can successfully trim the high leverage points away from the data. Finite sample performance of the proposed algorithm is evaluated by some extensive simulation studies, together with the comparisons made with other existing procedures in the literature.

Fitoplasmas são agentes causais de diversas doenças em numerosas espécies botânicas cultivadas, daninhas e silvestres. São procariotos que não apresentam parede celular, parasitas intracelulares obrigatórios, habitantes do floema e da hemolinfa, sendo transmitidos naturalmente por insetos vetores do tipo cigarrinhas. Plantas de oliveira apresentando sintomas tipicamente induzidos por fitoplasmas, caracterizados por desenvolvimento lento e superbrotamento de ramos com folhas de tamanho reduzido, foram observadas na cidade de Extrema (MG). A anomalia provoca danos significativos, pois retarda o início de produção e reduz o rendimento da cultura. Sintomas semelhantes foram relatados em olivais implantados em outros países, onde a doença foi associada aos fitoplasmas. O objetivo deste trabalho foi demonstrar a associação de fitoplasma com as plantas afetadas e identificar o fitoplasma presente nas árvores doentes. Para isto foram utilizadas as técnicas moleculares de PCR e RFLP, além de análise filogenética. Os resultados revelaram a presença de fitoplasmas em 73% das árvores sintomáticas analisadas, evidenciando que os sintomas observados no campo eram induzidos por fitoplasma. A doença foi denominada de vassoura-de-bruxa da oliveira. A identificação molecular permitiu classificar o fitoplasma como um representante do grupo 16SrVII-B. Este é o primeiro relato da ocorrência de fitoplasma em plantas de oliveira no Brasil. Em termos mais amplos, é o primeiro relato da associação de um fitoplasma do grupo 16SrVII com a doença vassoura-de-bruxa da oliveira, a qual, em outros países, está associada a fitoplasmas distintos do fitoplasma identificado no presente trabalho. / Phytoplasmas are causal agents of diverse diseases occurring in numerous botanical species, among them cultivated, weeds and wild plants. They are wall-less prokaryotes, obligate intracellular parasites, inhabitants of phoem vessels and hemolymph, and naturally transmitted by insect vectors belonging to the group of the leafhoppers. Olive trees exhibiting symptoms typically induced by phytoplasmas, characterized by slow growth and shoot proliferation with small leaves, were observed in the municipality of Extrema (MG). The anomaly provokes significant damage due to the delay in the beginning of the production and yield reduction of the crop. Similar symptoms have been reported in olive orchards cultivated in other countries, where the disease was associated with phytoplasmas. The objective of the present investigation was to demonstrate the association of phytoplasma with affected plants and identify the phytoplasma present in diseased trees. PCR assays, RFLP analysis and phylogenetic analysis were used to molecular characterization of the phytoplasma. The results revealed the presence of phytoplasma in 73% of the symptomatic trees, evidencing that the symptoms observed in field were induced by phytoplasma. The disease was designated by olive witches\" broom. The molecular identification allowed classify the phytoplasma as a representative of the 16SrVII-B group. This is the first report of the occurrence of phytoplasma in olive plants in Brazil. Moreover, this is also the first report of the association of a group 16SrVII phytoplasma with olive whitches\" broom disease, which has been described in other countries in association with phytoplasmas different from the phytoplasma identified in the present study.

The study of matter at extreme conditions has been of great importance for modern society. A correct understanding of materials and environments subject to high pressures and temperatures enabled the development of car and jet engines, manufacture of goods, energy production and space travels among other human milestones. Discoveries in magnetism, geology, chemistry, and crystallography have been reported in literature as well, illustrating relevant contributions of this research area. Science at extreme conditions constantly requires to innovate instruments and characterisation methods. Sophisticated proficiencies are needed to explore and reproduce conditions of interest for this field. Since the 1990s, high pressure instruments for neutron scattering have boosted the study of compressed matter. The design and subsequent improvement of the Paris-Edinburgh (PE) press and toroidal anvils successfully impacted this area, currently being the most extensively used instrument for high pressure neutron scattering, commonly used for pressures of the order of 10 GPa. Recent incorporation of toroidal anvils made of Zirconia Toughened Alumina (ZTA) has opened new experimental possibilities. Neutron transparency and mechanical resistance are key properties of this ceramic material. At this point it is essential to understand ZTA anvils design and working conditions in order to increase experimental capabilities and access new frontiers in compressed matter. Computer-based modelling technique Finite Element Analysis (FEA) has been a recent ally for instrumentation design and optimisation. Phenomena such as mechanical stress, deformations, and thermal distributions can be modelled in an object, gathering information regarding its mechanical stability, behaviour and failure. Although this method is popular in industrial and engineering design and applications, it has not been widely employed in high pressure research due to scarce information in material properties under extreme conditions, as well as in innovative ceramics and metallic alloys introduced in these types of scientific devices.

No description available.

Cette étude a pour principal objectif l'élaboration de la chronologie relative du vaste programme architectural de Jayavarman VII dont le royaume englobait la totalité du Cambodge et une large partie de la Thaïlande à la fin du XIIe siècle. La construction de la chronologie générale des monuments dits du style du Bayon s'est appuyée sur une analyse archéologique des principaux temples de cette période complétée par une étude stylistique basée sur les travaux de Ph. Stern [Ph. Stern, 1965]. Ces résultats ont été complétés et partiellement validés par une étude archéométrique portant sur le comportement magnétique du grès, principal matériau constituant ces monuments.<br />La chronologie locale et globale des monuments du style du Bayon a permis la mise au jour de quatre classes typologiques de temples régissant l'ensemble du programme architectural du Jayavarman VII. Il a été, de plus, possible de déduire quelles parties de celui-ci était exécutée dès 1191, date de consécration du Preah Khan d'Angkor. Cet essai de datation absolue des monuments du style du Bayon découle de l'analyse comparative de la chronologie relative de Ta Prohm et du Preah Khan d'Angkor avec leur description et la distribution de leur population divine qui en ont été faites dans les inscriptions de leur stèle respective.

The NASA Kennedy Space Center (KSC) is situated along the east coast of central Florida, where a high frequency of lightning occurs annually. Although cloud-to-ground (CG) lightning forecasting using radar echoes has been thoroughly analyzed, few studies have examined intracloud (IC) and/or total (IC CG) lightning. In addition to CG lightning, IC flashes are of great concern to KSC launch operations. Four years (2006-2009) of summer (June, July, August) daytime (about 14-00 Z) Weather Surveillance Radar – 1988 Doppler data for Melbourne, FL were analyzed. Convective cells were tracked using a modified version of the Storm Cell Identification and Tracking (SCIT) algorithm and then correlated to CG lightning data from the National Lightning Detection Network (NLDN), as well as grouped IC flash data acquired from the KSC Lightning Detection and Ranging (LDAR) networks I and II. Pairs of reflectivity values (30, 35, and 40 dBZ) at isothermal levels (-10, -15, -20 and updraft -10 degrees C), as well as a vertically integrated ice (VII) product were used to optimize criteria for radar-based forecasting of both IC and CG lightning within storms. Results indicate that the best radar-derived predictor of CG lightning according to CSI was 25 dBZ at -20 degrees C, while the best reflectivity at isothermal predictor for IC was 25 dBZ at -15 degrees C. Meanwhile, the best VII predictor of CG lightning was the 30th percentile (0.840 kg m-2), while the best VII predictor of IC was the 5th percentile (0.143 kg m-2), or nearly 6 times lower than for CG! VII at both CG and IC initiation was higher than at both CG and IC cessation. VII was also found to be lower at IC occurrence, including at initiation, than at CG occurrence. Seventy-six percent of cells had IC initiation before CG initiation; using the first IC flash as a predictor of CG occurrence also statistically outperformed other predictors of CG lightning. Even though average lead time for using IC as a predictor of CG was only 2.4 minutes, when taking into account automation processing and radar scan time for the other methods, lead times are much more comparable.