La technique de moyennation est un moyen efficace pour simplifier les transferts optimaux pour un satellite à faible poussée dans un problème à deux corps contrôlé. Cette thèse est une étude analytique et numérique du transferts orbital à poussée faible en temps optimal qui généralise l'application de la moyennation du problème à deux corps à des transferts dans le problème à deux corps perturbés et aux transfert d'une orbite proche de la Terre au point de Lagrange L1, dans le cadre du problème à quatre corps bi-circulaire où l’effet perturbatif de la Lune et du Soleil est modélisé. Dans le transfert à faible poussée à deux corps, nous comparons le cas du temps minimal et de l'énergie. Nous déterminons que le domaine elliptique pour les transferts orbitaux temps-minimal est géodésiquement convexe pour un transfert coplanaire et vers une orbite circulaire, contrairement au cas de l’énergie. Nous examinons ensuite l’effet la perturbation lunaire, nous montrons que dans ce cas le Hamiltonien moyenné se trouve être celui associé à un problème de navigation de Zermelo. Nous étudions numériquement à l’aide du code Hampath, les points conjugués pour caractériser l’optimalité globale des trajectoires. Enfin, nous construisons et réalisons numériquement un transfert d'une orbite terrestre au point de Lagrange L1, qui utilise la moyennation sur un arc (proche de la Terre) pour simplifier les calculs numériques. Dans ce dernier résultat nous voyons qu'un transfert concaténant une trajectoire moyennée avec une trajectoire temps minimal au voisinage du point de Lagrange est en effet proche d’un transfert de temps optimal calculé avec une méthode numérique de tir. / The technique of averaging is an effective way to simplify optimal low-thrust satellite transfers in a controlled two-body Kepler problem. This study takes the form of both an analytical and numerical investigation of low-thrust time-optimal transfers, extending the application of averaging from the two-body problem to transfers in the perturbed low-thrust two body problem and a low-thrust transfer from Earth orbit to the L1 Lagrange point in the bicircular four-body setting. In the low-thrust two-body transfer, we compare the time-minimal case with the energy-minimal case, and determine that the elliptic domain under time-minimal orbital transfers (reduced in some sense) is geodesically convex. We then consider the Lunar perturbation of an energy-minimal low-thrust satellite transfer, finding a representation of the optimal Hamiltonian that relates the problem to a Zermelo navigation problem and making a numerical study of the conjugate points. Finally, we construct and implement numerically a transfer from an Earth orbit to the L1 Lagrange point, using averaging on one (near-Earth) arc in order to simplify analytic and numerical computations. In this last result we see that such a `time-optimal' transfer is indeed comparable to a true time-optimal transfer (without averaging) in these coordinates.

Alkalic porphyry style Au-Cu deposits of the Cadia district are associated with Late-Ordovician monzonite intrusions, which were emplaced during the final phase of Macquarie Arc magmatism at the end of the Benambran Orogeny. N-striking faults, including the curviplanar, northerly striking, moderately west-dipping basement thrust faults of the Cadiangullong system, developed early in the district history. NE-striking faults formed during rifting in the late Silurian. Subsequent E-W directed Siluro- Devonian extension followed by regional E-W shortening during the Devonian Tabberabberan Orogeny dismembered these intrusions, thereby superposing different levels porphyry Au-Cu systems as well as the host stratigraphy. During the late Silurian, the partially exhumed porphyry systems were buried beneath the Waugoola Group sedimentary cover sequence, which is generally preserved in the footwall of the Cadiangullong thrust fault system. The Waugoola Group is a typical rift-sag sequence, deposited initially in local fault-bounded basins which then transitioned to a gradually shallowing marine environment as local topography was overwhelmed. Basin geometry was controlled by pre-existing basement structures, which were subsequently inverted during the Devonian Tabberabberan Orogeny, offsetting the unconformity by up to 300m vertically. In the Waugoola Group cover, this shortening was accommodated via a complex network of minor detachments that strike parallel to major underlying basement faults. For this reason, faults and folds measured at the surface in the sedimentary cover can be used as a predictive tool to infer basement structures at depth. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The aim of my diploma thesis was to optimize the gap shape of a turbocharger thrust (axial) bearing using the metamodeling. In its first part, the thesis focuses on introduction of optimization and metamodeling, description of different metamodeling techniques and description of a turbocharger with focus on lubrication of thrust bearing. The second part contains a calculation model of flow through the lubrication gap, use of the techniques for compiling a metamodel and the evaluation of individual techniques. Specifically, the methods used are response surfaces and kriging.

Cílem této diplomové práce je najít optimální profil mezery mazání pro turbodmychadlo. Cílem je minimalizovat tření, udržovat nosnost a nezvyšovat průtok maziva. Tato multiobjektivní optimalizace se provádí pomocí genetického algoritmu (GA) v MATLABu. Minimalizace třecí síly snižuje ztráty třecího výkonu turbodmychadla. Řešení Reynoldsovy rovnice je počítáno numericky pomocí MATLABu. Je zjištěna minimální tloušťka mazací mezery pro počáteční problém. Funkce spline se používá ke generování obecného profilu mazací mezery. Tento profil je poté optimalizován pomocí GA v MATLABu.

This Bachelor thesis at KTH Royal Institute of Technology in Stockholm covers a model-based analysis of thrust washer bearings in heavy trucks. This work treats Scania CV AB’s range-splitter gearbox. In this gearbox there are thrust washer bearings which are analyzed in this study. The purpose of the study is to examine the stresses the bearings are experiencing during load, determine which bearing (front or rear) that is most highly stressed, and discuss the cause for that. At large axial forces, which in turn lead to greater friction and thermal stress, there is a large risk for severe wear. Theoretically, there should not be any axial forces in a planetary gearbox with straight cut-gears, but because of the shape of the planet wheel carrier and the torque from the engine, the carrier and the needle bearings are distorted, which will cause an axial force. The axial force is not easily measured. Furthermore, it is also constantly changing during an actual driving sequence. Based on engineering judgement, the axial force was estimated to be 647 N. The axial force leads to all parts of the gearbox being pushed together axially, and cause friction forces to appear in surfaces that rotate relative each other. This process is analyzed with the FEM-program Ansys. Three possible scenarios were identified: (1) when the planetary wheel rotates relative the thrust washer bearing; (2) when the planetary wheel and needle bearing rotate relative the thrust washer bearing and (3) when the planet wheel carrier rotates relative the thrust washer bearing. The frictional heat power was simplified and analyzed as a heat power source and estimated to be 90 W. Cooling was modeled in Ansys as convection, with a film coefficient of 25 W/m2C. The initial temperatures used in the analysis were 22 and 90 °C. According to this, an equivalent stress of 12.3 MPa, and a maximum principal stress of 7.63 MPa, was located at the front thrust washer bearing. This occurs when the planet wheel and the needle bearing rotate relative to the thrust washer bearing, with an initial temperature of 90 °C. To validate the model, temperature sensors could be placed near the thrust washer bearings. However, since everything is rotating, this can be a difficult task. This report gives Scania a potential explanation to why the front and rear bearings in the gearbox are worn differently. / I det här kandidatexamensarbetet som genomfördes vid Kungliga Tekniska Högskolan i Stockholm gjordes en modellbaserad analys av axialglidlager som används i tunga lastbilar. Arbetet baserades på Scania CV ABs växellådor med range-splitter. I dessa sitter axialglidlager (även kallade brickor). Syftet var att undersöka hur stor påfrestning dessa utsätts för och försöka utröna vilken av brickorna (fram eller bak) som utsätts för störst belastning, samt diskutera vad detta skulle kunna bero på. Vid oönskade axiella krafter, som i sin tur leder till högre friktion och termoelastiska spänningar, är risken för nötning på brickorna stor. Teoretiskt sett ska det inte uppstå några axiella krafter i en planetväxel med rakkugg, men på grund av planethjulsbärarens utformning och det ingående momentet från motorn kan det uppstå en förvridning av hela bäraren och nållagren. Detta leder i sin tur till att en axiell kraft uppkommer. Denna kraft beräknades till 647 N med konservativa ingenjörsmässiga antaganden, eftersom axiella kraften inte kan mätas och ständigt varieras beroende på körprofil. Den axiella kraften medför att alla delar i planetväxeln pressas samman axiellt. En friktionskraft uppstår då mellan ytor som roterar i förhållande till varandra. Detta förlopp har analyserats med hjälp av FEM-programmet Ansys. Tre möjliga belastningsfall identifierades: (1) när planethjulet roterar mot axialglidlagret; (2) när planethjulet och nållagret roterar mot axialglidlagret, samt (3) när planethjulsbäraren roterar mot axialglidlagret. Den friktionsvärme som uppstår förenklades i modellen till en värmeeffekt på 90 W. Den värme som leds bort representerades som konvektion, med ett konvektionstal på 25 W/m2C. Som initialtemperaturer för FEM-analyserna användes 22 °C och 90 °C. En effektivspänning på 12,3 MPa och en största huvudspänning på 7,63 MPa uppstod i den främre brickan vid fallet när planethjul och nållager roterade mot axialglidlagret vid en intialtemperatur på 90 °C. För att kontrollera modellens rimlighet skulle temperaturgivare kunna installeras vid brickorna. Detta kan i praktiken dock bli svårt att genomföra då hela systemet roterar. Detta arbete ger Scania en möjlig förklaring till vad som skulle kunna orsaka en ojämn nötning fram och bak.

In public opinion, protection against asteroids impact has always been on the agenda of space engineering. Actually it started from 1994 when Shoemaker Levy stroke Jupiter. This protection works in two steps: detection of threat and deflection. Some space agencies and foundations monitor the sky and set up scenario. Although the sky is nowadays well monitored and mapped, there is no global plan nowadays against this threat. This paper focuses on the deflection step, and aims at forecasting which variables are involved and their consequences on the deflection mission. In fact the result depends on several factors, like the time before hazardous moment, the accuracy of detection tools, the choice of deflection method, but the most unpredictable are human factors. This study shows a strategy and so tries to give some new response parts to the global deflection problem.

During a rocket launch, the point at which the most thrust is needed is at lift-off where the rocket is the heaviest since it is full of propellant. Unfortunately, this is also the point at which rocket engines perform the most poorly due to the relatively high atmospheric pressure at sea level. The Thrust Augmenting Nozzle (TAN) investigated in this paper provides a solution to this dilemma. By injecting extra propellant into the nozzle but downstream of the throat, the internal nozzle pressure is raised and the thrust is increased, and the nozzle efficiency, or specific impulse is potentially improved as well. Using this concept, the payload capacity of a launch vehicle can be increased and provides an excellent option for single stage to orbit vehicles.

Background: Temporomandibular disorder (TMD) is a common and costly problem often leading to chronic pain. There exists moderate evidence for physical therapy (PT) interventions in the management of TMD. A known relationship between TMD and the cervical spine exists with some evidence to support cervical intervention treatments. Cervical spine thrust joint manipulation (TJM) is an effective PT intervention explored in a limited fashion for this population. Objectives: To determine the immediate and short term (1 and 4 week) effects of cervical TJM on pain, dysfunction, and perception of change in individuals with a primary complaint of TMD. Methods: In this single blind randomized clinical trial, individuals with TMD (n=50) were randomly assigned to receive cervical TJM or sham manipulation in 4 PT visits over 4-weeks. All participants also received behavioral education, a home exercise program, and soft tissue mobilization. Primary outcomes included jaw range of motion (ROM), Numeric Pain Rating Scale (NPRS), TMD Disability Index, Jaw Functional Limitation Scale (JFLS), Tampa Scale of Kinesiophobia (TSK-TMD), and Global Rating of Change (GROC). Self-report and objective measurements (with blinded assessor) were taken at baseline, immediately after baseline treatment, 1-week, and 4-weeks. A 2 x 4 mixed model ANOVA was used with treatment group as the between-subjects factor and time as the within-subjects factor. Separate ANOVAs were performed for dependent variables and the hypothesis of interest was the group by time interaction. Results: Statistically significant 2-way interactions were noted in JFLS (p = .026) and TSK-TMD (p = .008), favoring the thrust manipulation group. Both groups showed statistically significant main effects in all measures over time. GROC and PASS favored the thrust manipulation group with statistically significant differences in successful outcomes noted immediately after baseline treatment (NNT = 5) and at 4-weeks (NNT = 4). Conclusion: Both groups received identical multi-modal treatments with the addition of the randomized intervention: cervical TJM or sham manipulation. Differences between groups were small, however, improvements favored the TJM on all measures. Cervical TJM may be beneficial in the treatment of TMD.

The thesis is focused on the possibility of establishing correlation relationships for the strength characteristics of sprayed concrete. The aim of the thesis is to study the fundamental properties of sprayed concrete recipes. An important point of the thesis will bemade by spraying concrete compared with concrete made with laboratory pressure. Based on the achieved results will be compiled correlation equations for a given set of concrete.

© [2015] American Physical Therapy Association. / 京都大学 / 0048 / 新制・課程博士 / 博士(人間健康科学) / 甲第19641号 / 人健博第33号 / 新制||人健||3(附属図書館) / 32677 / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 市橋 則明, 教授 山田 重人, 教授 妻木 範行 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM