The focus in this thesis is to improve knowledge of the BWR related uncertainties void, channel bow, and control rods. The presence of void determines the moderation of neutrons in BWRs. A high void fraction is less efficient in moderating neutrons than a low one. As a consequence, the ratio of thermal to fast neutrons is dependent on the surrounding void fraction. In this thesis, calculations with 2D/3D codes corroborate this dependence, the void correlation, to be linear and very robust to changes in different reactor parameters. The void fraction could be predicted from the ratio of simultaneously measured reaction rates from thermal and fast neutron detectors over the whole core with an uncertainty of ±1.5%. The only parameter found disturbing the void correlation significantly is channel bow. However, since channel bow is the only phenomenon found biasing the void correlation, it is found that the void prediction methodology can be used to indicate channel bow with a sensitivity of 4% per mm bow. Consequently, large channel bows could easily be detected. Increased knowledge of void fractions and channel bow could increase both safety and economy of nuclear power production. This thesis also investigates how 2D/3D codes used in production perform in calculating detailed impact of control rods on pin powers and their ability to perform control rod depletion calculations in the reflector region. It is found that the axial resolution used in 3D nodal codes has very large impact on pin power gradients, i.e., using a standard nodal size of ~15 cm can cause underestimations of 50% in pin power gradients, which could lead to fuel damages. In addition, two methods for determining the neutron flux in the control rod when it is withdrawn from the core are presented. Both methods can be used in a 3D nodal code to reproduce the neutron flux in the reflector region with an uncertainty of ±3%. / Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 715

Vis aktyviau pasaulyje yra domimasi sentimentų analize. Verslininkai, garsių pasaulyje įmonių atstovai naudojasi sentimentų analizės įrankiais, kurie leidžia analizuoti tūkstančius vartotojų komentarų (Twitter, Facebook socialiniuose tinkluose, kituose tinklalapiuose). Išanalizavus internetinius komentarus suinteresuotos šalys mato kaip vertinami jų produktai ar paslaugos, prekės ženklai, darbuotojai. Tai naudinga informacija, kuri padeda valdyti savo verslą. Deja, tokių įrankių skirtų lietuvių kalbai nėra. Šio darbo tikslas išanalizavus nuomonių gavybos metodus parengti sprendimą tinkamą lietuviškų internetinių tekstų sentimentų analizei ir jį įgyvendinti. Šiame darbe yra analizuojami sentimentų analizės metodai, egzistuojantys sentimentų analizės įrankiai. Taip pat pateikiamas metodikos lietuviškų tekstų nuomonių analizei formulavimas, pagrindžiant bandymais. Darbo eigoje sukurtas įrankių rinkinys Python kalba, leidžiantis išbandyti siūlomą metodiką. Darbas užbaigiamas rekomendacijomis, kurios leistų patobulinti sukurtą įrankių rinkinį. / Interest in the analysis of sentiment in the world is rising. Entrepreneurs, representatives from world famous companies are using analysis tools ofsentiments that allow to analyze thousands of users comments (Twitter, Facebook,in social networks, or other sites). After analysis of online comments interested parties can see how is valued their products or services, brands, and employees. This is a useful information, that helps you to manage your business. Unfortunately, there is no such tools for the Lithuanian language. The aim of this analysis is to develop and implement methods for extracting the proper sentiments of decision in Lithuanian texts online. In this paper is an overview of analytical methods, existing sentiment analysis tools. It is also provided formulation of a methodology of Lithuanian texts opinion for its analysis, based on justification tests. During a work process was created a set of tools developed in Python that allows to test the proposed methodology. Work is completed with recomendations, which allows to improve the developed Toolkit.

This thesis reexamines the adoption of the bow and arrow in the Eastern Woodlands. Archaeologists have usually relied on the size and shape of projectile points to help them determine when the bow and arrow was adopted, since the other parts of this complex system (e.g., the wooden bows and arrow shafts) do not survive well in the Eastern Woodlands. The current belief is that the bow and arrow was introduced during the Late Woodland period (AD 500) in the Eastern Woodlands. This is based on the wide spread use of small stone projectile points and on their continued use up to European contact. However, this small point technology was actually established during the Late Archaic period (2000 BC). A wide range of evidence is presented in this thesis that shows that the bow and arrow may have been adopted during the Late Archaic period and was well established during the Middle Woodland period (AD 100) in several Eastern Woodland states. / Department of Anthropology

A comprehensive understanding of high-speed liquid jets is required for their introduction into engine and combustion applications. Their transient nature, short lifetime, unique characteristics and the inability to take many experimental readings, has inhibited this need. This study investigates the outflow of a high-speed liquid jet into quiescent atmospheric air. The key characteristics present are, a bow shock wave preceding the jet head, an enhanced mixing layer and the transient deformation of the liquid jet core. The outflow regime is studied in an experimental and numerical manner. In the experimental investigation, a high-speed liquid water jet is generated using the momentum exchange by impact method. The jet velocity is supersonic with respect to the impinged gaseous medium. The resulting jet speed is Mach 1.8. The jet is visualised with the use of shadowgraph apparatus. Visualisation takes place over a variety of time steps in the liquid jet???s life span and illustrates the four major development stages. The stages progress from initial rapid core jet expansion to jet stabilisation and characteristic uniform gradient formation. The visualisation shows that at all stages of the jet???s life it is axi-symmetric. One dimensional nozzle analysis and a clean bow shock wave indicate that the pulsing jet phenomenon can be ignored. In the numerical investigation, a time marching finite volume scheme is employed. The bow shock wave characteristics are studied with the use of a blunt body analogy. The jet at a specific time frame is considered a solid body. The jet shape is found to have an important influence on the shock position and shape. Analysis of the results indicates a shock stand-off similar to that seen in experimental observations and the prediction of shock data. The jet life span is modelled using a species dependent density model. The transient calculations reproduce the key jet shape characteristics shown in experimental visualisation. The mushrooming effect and large mixing layer are shown to develop. These effects are strongest when the shock wave transience has yet to stabilise. Quantitative analysis of the mixing layer at varying time steps is presented.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-07-12T19:42:05Z No. of bitstreams: 1 RAFAELLA DE ARAÚJO AIRES VILAR – DISSERTAÇÃO (PPGMET) 2016.pdf: 3521923 bytes, checksum: 8abe82b0df1c51917eb7f25334055e37 (MD5) / Made available in DSpace on 2018-07-12T19:42:05Z (GMT). No. of bitstreams: 1 RAFAELLA DE ARAÚJO AIRES VILAR – DISSERTAÇÃO (PPGMET) 2016.pdf: 3521923 bytes, checksum: 8abe82b0df1c51917eb7f25334055e37 (MD5) Previous issue date: 2016-02-26 / Capes / A formação de tornados é um fenômeno pouco frequente no Centro-Oeste do Brasil. O registro de um tornado em Brasília-DF em 01 de outubro de 2014 evidencia a importância da utilização de métodos que permitam compreender melhor os vários mecanismos atmosféricos dominantes em episódios de tempo severo e monitorar esse fenômeno meteorológico com alto potencial de destruição. Este estudo teve como propósito analisar a estrutura vertical da atmosfera que prevaleceu no desenvolvimento de condições atmosféricas adversas e identificar parâmetros convectivos adequados para determinação de padrões atmosféricos que favoreceram o desenvolvimento de tempo severo. A técnica estatística Análise de Componentes Principais (ACP), índices de instabilidade e imagens de radar meteorológico foram os principais métodos de análise utilizados. Os resultados mostram que a combinação entre o alto grau de instabilidade atmosférica, temperaturas elevadas e vento intenso acompanhado de rajadas foi determinante para o desenvolvimento do tornado. Entretanto, os valores dos índices de instabilidade diferem dos limiares normalmente utilizados como indicadores da formação de tornados. Linhas de instabilidade em forma de arco (“bow echoes”) detectadas pelo radar durante o período de chuva intensa com danos em superfície são os indícios mais fortes do tornado que atingiu a região. Registros fotográficos de linhas de energia, telhados, árvores e carros danificados pelo vento (95 km/h) também são apresentados. / The frequency of tornado formation in Central-West Brazil is low. A tornado observed in Brasília-DF on 01 October 2014 highligths the importance of using methods that allow a better understanding of the various atmospheric mechanisms that dominate in severe weather episodes, and the monitoring of this meteorological phenomenon with high destructive potential. The aim in this study was to analyze the vertical structure of the atmosphere that dominated the development of adverse atmospheric conditions and to identify convective parameters that are adequate for determining atmospheric patterns that favor severe weather development. The statistic technique Principal Component Analysis (PCA), instability indices and meteorological radar images were the main analysis methods employed. The results show that the combination of high degree of atmospheric instability, high temperatures and intense wind with gusts was determinant for tornado development. However, values of the instability indices differ from those normally used as indicators of tornado formation. Arc-shaped squall lines (“bow echoes”) detected by radar during the period of intense rainfall with damages at the surface are the strongest evidence of the tornado that hit the region. Photos of power lines, roofs, trees and cars damaged by the winds (95km/h) are presented also.

O arco facial tem seu uso descrito na literatura desde o início do século 20, e atualmente sua eficácia e precisão são controversas. Publicações recentes mostram que a sua reprodutibilidade é passível de erros. Este estudo teve como objetivo comparar a reprodutibilidade do arco facial com a de um novo dispositivo desenvolvido com nível de bolha para a montagem de modelos de gesso em articuladores semi-ajustáveis, por meio da análise de medidas realizadas com a Mesa de Erickson. Os modelos de gesso foram obtidos com moldes de alginato e montados em articulador semi-ajustável marca Bio-art, modelo a7 Plus. A avaliação da reprodutibilidade foi realizada em 10 participantes, com a obtenção de três montagens de seus modelos maxilares, sendo a primeira com o arco facial, a segunda com o dispositivo com nível de bolha estando o participante sentado e a terceira com o dispositivo com nível de bolha estando o participante em pé, cada método foi aferido 3 vezes, por 3 examinadores diferentes. Para cada montagem foram realizadas cinco medidas a saber: a) nas cúspides dos primeiros molares superiores de cada lado (dentes 16 e 26), b) cúspides dos caninos superiores de cada lado (dentes 13 e 23) e c) ponto interincisivo, localizado na linha média. Os valores obtidos foram submetidos ao Cálculo do Erro Técnico da Medida e ao Coeficiente de Variação interexaminador. O presente trabalho concluiu que o arco facial tem uma margem de erro em medidas repetidas maior do que o novo dispositivo desenvolvido. O novo dispositivo mostrou-se mais confortável para os participantes, mas necessita mais testes para avaliarmos sua eficiência. / The face bow has been described in the literature since the early 20th century, and currently its effectiveness and accuracy are controversial. Recent publications show that the reproducibility is error-prone. This study aimed to compare the reproducibility of the face bow with a new device developed with bubble level for the assembly of plaster models in semi-adjustable articulators, through the analysis of measurements performed with Erickson table. The plaster models were obtained with alginate molds and mounted on semi-adjustable articulator brand Bio-art, a7 Plus model. Evaluation of reproducibility was conducted in 10 participants, obtaining three assemblies of their maxillary casts, the first one with the face bow, the second with the bubble level device with the participant being seated and the third level with the device bubble being the participant standing, each method was measured 3 times by 3 different examiners. For each assembly five measurements were performed as follows: a) in the cusps of the upper first molars on each side (teeth 16:26), b) cusps of upper canines on each side (teeth 13:23) and c) interincisal point, located in midline. The values obtained were subjected to measurement of the Technical Error Calculation and inter Coefficient of Variation. This study concluded that the face bow has a margin of error in repeated measurements greater than the newly developed device. The new device was more comfortable for the participants, but it needs more testing to evaluate their efficiency.

Les guerriers kouchites avaient la réputation d’exceller en tant qu’archers, les anciens Égyptiens appelant ainsi la région Ta-Seti : « le Pays de l’arc ». Kouch est le nom d’un district mais également d’une entité politique. Et comme toute entité politique, les différents royaumes de Kouch présentaient une force guerrière, une force armée qui n’a cessé d’évoluer durant les siècles, dû également à la série d’importantes occupations égyptiennes et kouchites sur ce territoire. Cette étude consiste en une description et une classification typologique et technique des armes et équipements d’armes fabriqués et utilisés durant l’Antiquité dans le Nord du Soudan : couteaux, dagues, épées, haches de combat, massues, lances, carquois, arcs, flèches, brassards et anneaux d’archer, etc. Adaptées au contexte militaire de chaque époque, ces armes sont pour l’archéologie des outils de connaissance, les témoins d’une situation qui n’a cessé d’évoluer en fonction de multiples critères tels que la notion de « chaîne opératoire », l’organisation des ateliers, le savoir-faire des artisans, les choix et les influences techniques, stylistiques et culturels, les échanges commerciaux, la distinction entre importations et fabrications locales, le statut des guerriers et des autres porteurs d’armes, les dépôts en contexte funéraire, et, naturellement, les symboliques politiques et religieuses qui s’y rattachent. / Kushite warriors were reputed to excel as archers, ancient Egyptians called the region Ta-Seti, “the land of bow”. Kush is the name of a district but also a political entity. As any political unit, the different kingdoms of Kush had a warrior force, which has continuously evolved over the centuries, due also to the series of Egyptian and Kushite occupations of the territory. This study consists of a description and a typological and technical classification of weapons produced and used during the Sudanese antiquity: knives, daggers, swords, battle axes, maces, spears, quivers, bows, arrows, archer braces, archer rings, etc. Adapted to the military context of each period, these weapons are tools of knowledge, witnessing a situation that has evolved based on multiple criteria such as the notion of “chaîne opératoire”, the organization of workshops, the skills of artisans, the technical, stylistic and cultural choices and influences, the distinction between imports and local manufacturing, the warriors status, the funerary deposits, and the political and religious symbols attached to it.

In recent years, fuel assembly bow in Ringhals 3 has started to increase again after lower levels of bow. Normally, the fuel assemblies are straight axially. One of the consequences of fuel assembly bow is perturbed power distribution across the core, resulting in smaller margins of safety during operation. A way of ensuring safe operation is add-on margins, penalties, dependent on bow amplitude, added to the power peaking factors. A new method of producing these penalties, based on realistic water gap distribution derived from measurements, was used. By comparing the new penalties with the currently used penalties, the currently used penalties were concluded to be around 10 percent smaller for both FdH, the radial power peaking factor penalty, and FQ, the local power peaking factor penalty. The currently used penalties hence are significantly lower. However, the conclusion should be seen as an indication, rather than directly implementable, since there is potential to evolve the method further and eliminate sources of error.

L'archet, élément indispensable à la production sonore des instruments à cordes frottées, a jusqu'à présent fait l'objet de peu d'études scientifiques. Le travail présenté a pour objectif de mieux comprendre son comportement mécanique en situation de jeu. À cette fin, des modèles numériques sont développés. La baguette, précontrainte par la tension du crin, est modélisée par des éléments finis de poutre en formulation corotationnelle, afin de prendre en compte la non-linéarité géométrique inhérente au problème. Un premier modèle (2D) rend compte du comportement de l'archet dans le plan. Il donne lieu à une étude numérique sur une géométrie standard, visant à mettre en évidence l'influence des paramètres de fabrication et de réglage sur le comportement de l'archet sous tension. Un second modèle (3D) intègre le caractère tridimensionnel des sollicitations rencontrées en situation de jeu, prenant en compte la flexion latérale de la baguette. Une procédure non destructive de détermination des propriétés mécaniques du bois et de la mèche, basée sur une méthode inverse utilisant le modèle 2D, est proposée. À titre de validation expérimentale, des résultats numériques obtenus avec le modèle 3D sont confrontés aux résultats de mesures sur deux archets, pour différents réglages du cambre et de la tension. L'effet de la précontrainte sur la raideur de flexion latérale de la baguette est mis en exergue. Le bon accord observé confère au modèle un caractère prédictif, offrant des perspectives d'utilisation en tant qu'outil d'aide à la facture. Par ailleurs, la stabilité de l'archet est un problème que les facteurs doivent prendre en considération. Un modèle phénoménologique basé sur un système mécanique simple est présenté. Il vise à donner certaines tendances sur les conditions d'apparition d'une instabilité par bifurcation ou par point limite, en faisant une analogie avec les propriétés de l'archet. Le calcul numérique du comportement pré- et post-critique de l'archet permet d'identifier des cas d'instabilité similaires, dont on discute les conséquences possibles sur le jeu et la facture. Dans une dernière partie, des essais en jeu axés sur les réglages du cambre et de la tension sont effectués par des musiciens. Les résultats de ces tests subjectifs tendent à montrer l'influence des paramètres de réglage examinés dans l'appréciation des qualités de jeu. / The bow, which is essential to produce the sound of bowed string instruments, has been little studied. The present work aims to better understand its mechanical behavior in playing situation. To this end, numerical models are developped. The stick, which is prestressed due to hair tension, is modelized by beam finite elements. A corotational formulation is adopted to take into account geometric nonlinearity. A first model (2D) concerns the in-plane behavior of the bow. It is used within a numerical study aiming at showing the influence of making and adjusting parameters on the tightened bow. A second model (3D) takes into account out-of-plane loading that makes the stick bend laterally. A non-destructive procedure to determine mechanical properties of wood and hair is proposed. It is based on an inverse method using the 2D model. As an experimental validation, numerical results obtained with the 3D model are confronted to measurement on two bows, for different settings of camber and hair tension. The effect of prestress on lateral bending stiffness is highlighted. A good agreement is observed. Thus, the model can be considered as predictive and might be used as an aid to bow making. Furthermore, the stability of a bow is a problem considered by bow makers. A phenomenological model based on a simple mechanical system is presented. It aims to give tendancies on conditions at which bifurcation or limit point instability can occur, by drawing an analogy with the bow. The numerical computation of pre- and post-critical behavior of the bow shows similar instability cases. Their possible consequences on playing and making are discussed. Finally, playing tests with musicians are carried out, focusing on the adjustment of camber and hair tension. The results tend to show the influence of the considered adjustment parameters on the assessment of playing qualities.

The thesis deals with constructing and solving a discrete mechanical model from the point of view of dynamics. As an example of a real-world problem which can be approximated in this way, the dynamical behaviour of a bow and arrow during loose have been chosen. In order to solve this particular type of model, a specialized piece of software has been developed. This method and software have been deployed to simulate shooting a straight bow of specific parametres. Two variants for the shape of the bowstaff have been evaluated.