A dificuldade de realizar a patência apical, tendo em vista que os canais radiculares apresentam algum grau de curvatura, exigiu o desenvolvimento de instrumentos rotatórios para agilizar o tempo operatório e facilitar sua execução. O objetivo deste estudo foi avaliar a influência de diferentes instrumentos de patência, utilizados 1 mm além do forame apical, no tempo de ação, transporte e centralização do canal radicular de canais radiculares curvos. Trinta e três raízes mesiais de molares superiores com curvatura entre 20 e 40 graus e raio menor que 10 mm foram selecionadas e divididas em 3 grupos (n = 11): R-Pilot #12.5 taper 0.04 (VDW, Munich, Alemanha), ProDesign Logic #25 taper 0.01 (Easy Equipamentos Odontologicos, Belo Horizonte, Brasil) e ProGlider #16 e taper variável de 0.02 a 0.08 (Dentsply Maillefer, Ballaigues, Suiça). Através de imagens pré e pós-operatórias de microtomografia computadorizada foram feitas as análises de transporte e centralização do canal radicular. Ainda, o tempo de ação de cada um dos instrumentos foi cronometrado. Para avaliar o transporte, foi utilizado o teste ANOVA. Para avaliar a centralização foi utilizado o teste Kruskal-Wallis. O tempo de ação foi avaliado pelo teste de Kruskal-Wallis e Post hoc de Dunn. O nível de significância foi de 5% para todos os testes aplicados. Não houve diferença estatística entre os grupos nas análises de transporte e centralização. Já na análise de tempo, o instrumento ProGlider se mostrou significativamente mais rápido se comparado com o ProDesign Logic 25.01 (P<0,05), o instrumento R-Pilot não foi diferente do ProGlider e Logic (p>0,05). Os instrumentos de patência utilizados neste estudo, e trabalhados 1 mm além do forame apical, permaneceram relativamente centralizadas dentro do canal radicular e promoveram transporte apical mínimo, sendo clinicamente irrelevante. / The difficulty of performing the apical patency, considering that the root canals present some degree of curvature, required the development of rotary instruments to speed up the operative time and facilitate its execution. The aim of this study was to evaluate the influence of different glide path files, used 1 mm beyond the apical foramen, on the preparation time, apical transportation and centering of the root canal of curved roots. Thirty three mesiobuccal roots from maxillary molars, with 20 to 40 degrees of curvature and presenting radio curvature lower than 10 mm were selected and divided in 3 groups (n = 11): R-Pilot #12.5 taper 0.04 (VDW, Munich, Germany), ProDesign Logic #25 taper 0.01 (Easy Equipamentos Odontologicos, Belo Horizonte, Brazil) ProGlider #16 e taper variable of 0.02 to 0.08 (Dentsply Maillefer, Ballaigues, Switzerland). Analysis of transportation and centration of root canal was performed using pre and postoperative computerized microtomography images and the work time of each file was measured. To evaluate the apical transportation, ANOVA test was used, while a Kruskal-Wallis test was used to assess centering ability. As for action time, Kruskal-Wallis and Dunn tests were performed. The level of significance was 5 % in all tests. No statistical difference was found amongst the groups for the variables apical transportation and centralization. When evaluated the action time, the ProGlider file has been significantly faster when compared to ProDesign Logic 25.1 (P<0.05).while R-pilot has not differed from ProGlider and Logic (P>0.05). The glide path files used – 1 mm beyond the apical foramen – remained relatively centralized inside the root canal and promoted minimal apical transportation, expressing no clinical relevance.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22237号 / 理博第4551号 / 新制||理||1654(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 柳瀬 陽一, 教授 川上 則雄, 教授 松田 祐司 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Bakgrund: Fotleden används dagligen och en nedsatt fotledsrörlighet kan orsaka många problem för personer i vardagen. Knäböj är en rörelse som används både i vardagen samt i träningssammanhang och kräver en god dorsalflexion i fotleden. Det är därför värdefullt att som fysioterapeut veta vilken metod som ökar dorsalflexion inför ett rehabiliteringsprogram där knäböj ingår. Syfte: Sammanställa litteraturen gällande akuta effekter av dynamisk och statisk stretching samt posterior talocrural glide på dorsalflexion i talocruralleden hos friska individer, definierat som personer utan fysiologisk sjukdom eller trauma med eventuell påverkan på fotleden. Studien syftar även till att värdera graden av evidens för behandlingarna. Metod: Litteratursökning utfördes i databasen PubMed. Slutligen inkluderades åtta studier med sammanlagt 141 deltagare. Samtliga studier kvalitetsgranskades enligt PEDro scale, därefter användes SBU:s GRADE för evidensbedömning. Resultat: Statistisk signifikant ökning på dorsalflexion för samtliga metoder med liknande utslag på rörlighet, med liten fördel för statisk stretch. Kvalitetsgranskning enligt PEDro scale visar på att fem studier anses vara av måttlig till hög kvalitet och tre anses vara av låg kvalitet. Otillräckligt vetenskapligt underlag för posterior talocrural glide, statisk och dynamisk stretch på dorsalflexion. Konklusion: Statisk stretch, dynamisk stretch och posterior talocrural glide ökar dorsalflexionen efter minst två minuters behandling. Evidensen talar för att samtliga metoder ger liknande utfall på dorsalflexionen med en liten fördel för statisk stretch, men fler studier behövs för att bekräfta resultatet. / Background: Demands are put on the ankle daily. Limited ankle range of motion can present problems during daily activities. The squat is a movement performed both in everyday life as well as in the context of training and requires ample dorsiflexion of the ankle. Therefore, it is of value to physiotherapists to know which method should be used to increase dorsiflexion in a rehabilitation protocol where the squat is included. Objective: To provide an overview of the acute effects of static and dynamic stretching as well as posterior talocrural glide in healthy individuals without physiological diseases or trauma relating to the ankle. The study will also assess the level of evidence surrounding each of these methods. Method: The database PubMed was used to search for the included studies. A total of eight studies was included in this review, with a total of 141 participants. Study quality was judged using PEDro scale, after which SBU’s GRADE was used to determine the level of evidence for each method. Result: A statistically significant increases present for each of the methods, with similar outcomes on the dorsiflexion. Assessing the quality of the included studies with PEDro scale resulted in five studies of moderate to high quality and three of low quality. Evidence supporting posterior talocrural glide, static and dynamic stretching is deemed insufficient according to SBU’s GRADE. Conclusion: Dorsiflexion is increased after two minutes of static and dynamic stretching as well as posterior talocrural glide. The evidence suggests that similar increases are present with each method, with static stretch showing a slightly higher result. However further research is required to confirm the result.

Des amas de lacunes ont été observés et caractérisés expérimentalement dans les métaux de haute pureté après déformation plastique ou après une suite de traitements thermiques particuliers. Ces amas sont des obstacles à la propagation des dislocations et peuvent par conséquent induire un durcissement du métal.Cette étude par simulations numériques a permis d'explorer différents mécanismes de propagation de dislocations dans une concentration d'amas en fonction de la contrainte de cisaillement appliquée et de la température. À haute contrainte, la force appliquée sur la dislocation devient supérieure aux forces d'ancrage s’exerçant sur la ligne. La dislocation franchit la distribution d'amas en glissant et en cisaillant les amas. La dépendance de la force d'ancrage en fonction de la taille de l'amas est ajustée sur nos simulations de statique moléculaire. Dans ce domaine de contrainte, les configurations d'amas ancrant la dislocation sont rares et l'activation thermique suffit à désancrer la ligne. La probabilité de désancrer la ligne dépend de l'enthalpie d'activation, un paramètre que nous avons également estimé à l'aide d'un modèle analytique ajusté sur nos résultats atomistiques. À plus faible contrainte, lorsque la force appliquée est inférieure aux forces d'ancrage induites par les amas, la probabilité que la dislocation se désancre uniquement par glissement devient faible. La diffusion des lacunes, émises préférentiellement des amas, intervient alors et favorise la formation de crans. Cela contribue au désancrage de la ligne. Ce mécanisme est le glissement assisté par la montée. Les barrières d'émission, d'absorption et de migration de lacunes ont été déterminées par statique moléculaire et sont fortement dépendantes du champ élastique et de la distorsion du réseau atomique générés par la présence de la dislocation. Cela induit une forte anisotropie de diffusion au voisinage des dislocations qui conduit notamment au mécanisme de 'pipe diffusion'. L'évolution au cours du temps de l'ensemble de ces mécanismes a été étudiée à l'aide d'un modèle de ligne élastique couplé à un algorithme de Monte Carlo cinétique dont l'ensemble des barrières d'énergie provient de nos simulations atomistiques. Moyennant les hypothèses du modèle, nous avons alors obtenu une estimation de la vitesse des dislocations en fonction de la contrainte et de la température appliquée. Nous avons ensuite utilisé la loi d'Orowan pour estimer la vitesse de déformation liée à ces mécanismes. / Vacancy clusters have been observed and characterized experimentally in highly pure metals after plastic deformation or after a particular sequence of heat treatments. These clusters hinder the dislocation propagation and can therefore harden the metal.Using numerical simulations we have explored different mecanisms of dislocation propagation through a vacancy-cluster distribution, for several applied shear stress and temperature. At high stresses, the force applied on the dislocation becomes greater than the pinning forces acting on the line. The dislocation gets through the cluster distribution by gliding and shearing the clusters. The dependence of the pinning force with the cluster size is adjusted on our molecular static simulations. In this stress range, the pinning configurations are rare and the thermal activation is sufficient to unpin the line. The probability for the line to pass the pinning configuration depends on the activation enthalpy, a parameter that we have also estimated using an analytical model adjusted on our atomistic results. At lower stresses, when the applied force is below the pinning forces induced by the cluster, the probability that the dislocation unpins by pure glide becomes negligeable. The diffusion of vacancies, emitted preferentially from the vacancy clusters, intervenes and promotes the formation of jogs that contributes to the unpinning of the line. Such a mecanism is the glide assisted by climb. The emission, the absorption and the vacancy migration barriers have been determined by molecular static and are highly dependent on the elastic field and the atomic network distortion induced by the dislocation. This promotes a strong diffusion anisotropy in the vicinity of the dislocations which leads in particular to the pipe diffusion mechanism. The evolution with time of all these mechanisms has been studied using an elastic line model coupled to a kinetic Monte Carlo algorithm in which the parameters come from our atomistic simulations. According to the model assumptions, we obtained an estimation of dislocation velocity as a function of the applied shear stress and the temperature. We used the Orowan's law to estimate the strain rate related to such mechanisms.

Student Number : 9800022T - PhD thesis - School of Mechanical, Industrial and Aeronautical Engineering - Faculty of Engineering and the Built Environment / For many applications, it may be useful to be able to estimate creep properties of a material from simpler testing procedures such as tensile tests than the conventional creep testing procedures. Most alloys used for creep service conditions are in a hardened condition and thus tertiary creep, controlled by micro structural degradation, is dominant. The object of the study was to investigate a reasonably simple method for estimating the creep behavior of a low alloy 1% Cr, 0.25 % Mo steel from tensile yield data. The study involved performing of series of investigations, including age hardening, tensile and creep tests. Microstructural degradation was monitored from specimens held in a furnace for different times and temperatures, which were then tested in tension at room temperatures. Tensile tests were carried out at different temperatures and strain rates and the data used to determine material parameters for use in kinetic equations describing deformation. For comparison, creep curves were obtained from both creep tests and tensile tests results. Tests on furnace aged specimens were used to quantify softening due to material degradation and formulate a structure evolution and kinetic expressions used to determine creep curves. The modified equation by Dorn was used to determine the material parameters and to predict flow characteristics. Two sets of mechanisms were observed. At low temperature and high stress (above 550MPa) dislocation by glide mechanism was investigated. At higher temperatures and low stress (below 550MPa), some form of power law creep was observed. Glide mechanism was investigated and material parameters σ ) , n and activation volume v, were calculated. The calculated value of σ ) was assumed for both plastic deformation and the softening kinetics. A reasonably good estimate of the creep behavior of the low alloy steel used in this investigation in which tertiary creep dominates can be calculated from tensile yield stress values. Furthermore, the creep rate and recovery have similar stress dependences, with the stress and temperature dependence similar to that predicted by recovery theory. The value of activation energy observed for creep for this alloy is in line with the processes which could be related to self diffusion. In order to justify the significance of this study, four existing empirical models are discussed, highlighting their merits and demerits with respect to the models used in this study. These are θ-Projection, Damage Mechanics, Estrin-Mecking and the Internal Stress Methods. Generally, in this class of alloys, recovery process occurs under an effective stress (i.e. an applied stress less the internal stress). Thus the possibility of using tensile data obtained in this study in the internals stress model was explored. The model could replicate the one used in this study if the change in internal stress value o σ is assumed to be negligible. This could be assumed to be true for tensile data at high stresses and low temperature especially during secondary creep rate when the internal stress approximates to the applied stress and at short test durations.

An integration of geological and geophysical techniques has been used to characterize the internal structure of the Little Valley Landslide in Draper, Utah, USA. The Little Valley Landslide is a pre-historic landslide as old as 13ka B.P. It is found to consist of chaotic and disturbed weathered volcanic units derived from Tertiary age volcanics that comprise a great portion of the Wasatch Range. Geotechnical investigations that were integrated with the geophysical results included excavation of trenches and drilling of boreholes. Geophysical methods, in particular high-resolution seismic data, were used to provide a framework for interpreting the geotechnical observations. High-resolution seismic reflection data, seldom used in landslide investigations, were acquired and processed in order to image the basal or glide surface of the landslide and the structure underlying the landslide. The integration of the geotechnical and geophysical investigations provided a better understanding of the geometry of a portion of the Little Valley Landslide. Trenching and drilling identified landslide material in the subsurface. The high-resolution seismic reflection data imaged the glide surface with the onset of coherent reflectivity. A decollement or glide surface underlies the landslide indicating a large mass movement. The glide surface is observed on the seismic reflection profiles to be deepest in the center portion of the landslide. It is observed in the seismic reflection images to shallow up slope and creating a trough-like shape feature. A contour map modeling the middle of the Little Valley Landslide is derived from the seismic data. This study shows that seismic reflection techniques can be successfully used in complex alpine landslide regions. They are also efficient and cost-effective tools when compared to trenching and drilling investigations. The seismic data can (1) provide a framework to link geological data and (2) take the place of an extensive trenching and drilling program.

The aim of this project is to design and implement a drive system and a driving strategy for a lightweight, battery-driven rail vehicle partaking in the Delsbo Electric student competition. The goal of the competition is to create a vehicle which consumes as little energy as possible.  A simulation model of the vehicle is developed in Simulink, based on existing hybrid car models. Different drive cycles are written in MATLAB and tested in the vehicle simulation, which calculates energy consumption, power and torque usage and other important data. This data is used to select an optimal driving strategy and dimension the drive system components.  The final drive system design consists of a permanent-magnet synchronous motor powered by lead acid batteries and controlled by a microcontroller and motor driver through a user interface consisting of a control board with buttons and switches.  The chosen driving strategy combines slow acceleration and constant speed in slopes with the pulse and glide strategy on flat parts of the track. The simulation shows a total energy consumption of 0.67 Wh/person and km, which is in the same order of magnitude as results from previous years, which is promising for the competition. However, the actual energy consumption can not be known until the vehicle has been built and tested. There is a lot of uncertainty around its parameters at this stage, which affects the reliability of the simulations. / Syftet med det här projektet är att designa och implementera ett drivsystem och en körstrategi för ett lättviktigt, batteridrivet rälsfordon. Fordonet ska användas i studenttävlingen Delsbo Electric. Målet med tävlingen är att bygga ett fordon som förbrukar så lite energi som möjligt.  För att göra detta utvecklas en simuleringsmodell av fordonet i Simulink, baserat på redan existerande modeller av hybridbilar. Olika körprogram skrivs i MATLAB och testkörs i modellen, som beräknar energiåtgång, använd effekt och vridmoment och annan viktig data. Dessa värden används sedan för att optimera körstrategin och dimensionera drivsystemets komponenter.  Det färdigdesignade drivsystemet består av en permanentmagnetiserad synkronmotor som matas från blyackumulatorer och styrs av en mikrokontroller och en driver via en kontrollpanel med knappar och switchar. Den valda körstrategin kombinerar låg acceleration och konstant hastighet i backarna med pulse-and-glide-strategin på de platta delarna av banan. Enligt simuleringarna ger den en total energiåtgång på 0.67 Wh/person-km, vilket är i samma storleksordning som tävlingsresultat från tidigare år. Detta bådar gott inför tävlingen, men det går inte att veta hur stor den faktiska energiförbrukningen kommer bli förrän fordonet är byggt och testat. Än så länge är många av dess parametrar osäkra, vilket påverkar tillförlitligheten hos simuleringarna. / Kandidatexjobb i elektroteknik 2022, KTH, Stockholm

The goal of this project was to design a lens utilisinga glide symmetric periodic structure. A Lüneburg lens forantennas with a center frequency of 8 GHz has been designed.The structure was constructed using a unit cell in the shape ofan angular Bowen knot. This unit cell was then etched on themetallic surface of a parallel plate waveguide. Two symmetrycases for the unit cell were studied, the mirror symmetry andthe glide symmetry. Mirror symmetry is when the unit cell wasmirrored on the opposite metallic sheet, and glide symmetrywhen the cell was mirrored and shifted half a period. Theglide symmetric case was found to be less dispersive and moreisotropic. Further, we study the influence on the refractive indexwhen changing the geometry of the unit cell. A sufficient rangeof refractive index for realising the lens was found. These resultswere used to construct a full lens. Simulation of the complete lensshows the desired point to planar wave behavior of a Lüneburglens. In conclusion, the angular Bowen knot with glide symmetryhas the potential to construct a functioning Lüneburg lens. / Målet för detta projekt var att konstrueraen lins med glidsymmetriska periodiska strukturer. En Lüneburg-lins för antenner med en centerfrekvens på 8 GHz har de-signats. Strukturen byggdes med en enhetscell i formen avett sankthanskors etsat på en metallisk plattkondensator fylldmed ett dielektriskt substrat. Två symmetrifall betraktades,spegelsymmetri, då enhetscellen speglades på motstående me-tallskikt, och glidsymmetri där den även var förskjuten en halvperiod. Glidsymmetrin fanns ha mindre spridning och störreisotropi. Därtill undersöktes förändringarna i brytningsindex dåenhetscellens geometri förändrades. En tillräcklig räckvidd avbrytningsindex kunde uppnås. Dessa resultat användes för attkonstruera en fullständig lins. Simulering av den kompletta linsenvisade det önskade punkt till planvågbeteendet hos en Lüneburglins. Slutsatsen är att enhetsceller i formen av ett sankthanskorsmed glidsymmetri har potentialen att konstruera fungerandeLüneburg-linser. / Kandidatexjobb i elektroteknik 2020, KTH, Stockholm

<p dir="ltr">Experiments were performed in the Boeing/AFOSR Mach-6 Quiet Tunnel to study the effect of flight-derived discrete roughness elements repeated in an axisymmetric pattern near the nose of a sharp 7° cone. The aim of the roughness array was to simulate natural vehicle roughness and attempt to introduce a deterministic roughness pattern with the ability to cancel out the instabilities caused by the natural roughness. The cone was pitched at a 6° of attack to determine the three-dimensional flow field effects of the roughness elements. Tests were also ran at 0° of attack for comparison. Quiet flow testing included the designed-for freestream unit Reynolds number of 10.8x10⁶, and Reynolds numbers above and below. In noisy flow, comparable Reynolds numbers were also tested at to isolate the effects of noise in a conventional flow wind tunnel.</p><p dir="ltr">Infrared thermography and surface pressure sensors were used to document the behavior of the boundary layer. It was found that the roughness pattern was in general unsuccessful in controlling the added boundary layer instabilities as intended at 6° of attack, but it did create different instability amplitudes and heating patterns. Additionally, it was determined to reduce Mack's second-mode instability amplitudes at 0° of attack.</p><p dir="ltr">Additionally, work was done to document and characterize the roughness patterns found on samples of hypersonic glide vehicles PRIME (SV-5D or X-23) and ASSET (ASV-3). These samples were taken in the form of molded impressions of the surface which were able to be analyzed with an optical profilometer and considered for future experimental distributed roughness studies.</p>

La panne de moteur est une situation critique pour la sécurité du vol. L’objectif de cette thèse est d’améliorer la gestion de la trajectoire avion d’urgence dans le cas d’une panne totale de moteur en un certain point de vol alors que l’avion a déjà pris une certaine vitesse et une certaine altitude après le décollage. Dans cette étude, on considère que la trajectoire de vol plané le long d’un plan vertical peut conduire directement à un lieu atterrissage sûr. Les performances d’un avion de transport sont d’abord analysées, et les lieus atteignables sont établis à partir d’une situation donnée initiale. Une fois une zone de sécurité accessible existe le problème qui est abordée ici est de développer un système de guidage qui permet à l’avion d’effectuer une trajectoire faisable vers la zone d’atterrissage. La programmation dynamique inverse est utilisée pour construire en arrière des ensembles de trajectoires faisables vers conditions finales compatibles avec panne de moteur. Afin d’obtenir un dispositif en ligne pour générer des directives efficaces pour le pilote automatique ou le pilote humain (par un directeur de vol), un réseau de neurones est construit à partir de la base de données générée. Ensuite, les résultats de simulation sont analysés pour validation, et d’autres améliorations de l’approche proposée sont prises en considération. / Engine-out is an undoubted critical situation for flight safety. The objective of this thesis is to improve the management of emergency manoeuvres for transportation aircraft once all engines go out at a given point during the flight. Here we consider the evolution of the gliding aircraft along a vertical plane possibly leading directly to a safe landing place. The gliding qualities of standard transportation aircraft are first analyzed and reachable areas from given initial situations are established. Once a safe reachable area exists the problem which is tackled here is to develop design principles for a guidance system which makes the aircraft perform a feasible glide trajectory towards such landing area. Reverse dynamic programming is used to build backwards sets of feasible trajectories leading to final conditions compatible with engine-out landing. To get an on-line device to produce efficient directives for the autopilot or the human pilot (through a flight director), a neural network is built from the generated database. Then simulation results are analyzed for validation and further improvements of the proposed approach are considered