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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Dynamic mechanical studies of hydrolytic degradation in isotropic and oriented Maxon B.

Ward, Ian M., Hill, S.P., Klein, P.G., Rose, J., Montez De Oca, H., Farrar, D. 28 July 2009 (has links)
No / Hydrolytic degradation studies have been undertaken on Maxon B, a bioresorbable block copolymer of polyglycolic acid (PGA) and polytrimethylene carbonate (TMC). Isotropic and oriented samples were studied by dynamic mechanical measurements over a wide range of temperatures. In addition to mechanical tests, water content and mass loss were also determined on the degraded samples. At early stages of degradation water content was the dominant factor and plasticisation lead to reductions in the glass transition temperatures of the PGA and TMC components. Orientation was shown to give significant improvements in the mechanical properties, including overall increases in modulus and an increase in the glass transition temperature of the PGA component, which is important for the behaviour at body temperature (37 °C). Oriented samples also showed significantly less reduction in mechanical properties on degradation. Simple one-dimensional Takayanagi models were used to provide useful insight into the understanding of the mechanical behaviour.
2

Dvouosý pohon s EC motory Maxon / Two-axle drive with EC Maxon motors

Nevole, Josef January 2008 (has links)
The content of this master´s thesis is compact complex piece of knowledge from semestral projects 1 and 2. These semestral projects deal with analysis two-axle servo - drive, most common methods design regulators, design regulators and their simulation. Further was analysed quality regulation integral criteria, whereupon connect simulation circular and linear interpolation. Simulation was effected by force of Matlab Simulink. In one’s chapter was tested effect feedforwards to regulation. In closing parts is acquaint with control section position EPOS, and programming environment Open PCS company Maxon. In this environment was biaxial drive with EC motors Maxon and control section EPOS P 24/5 programmed. Results was discusseds with simulation.
3

Non-conventional Many-body Phases in Ultracold Dipolar Systems / Phases à N corps non-conventionnelles dans des systemes ultra-froids dipolaires

Fedorov, Aleksey 28 June 2017 (has links)
Le problème de la détection et de ladescription des nouveaux états quantiquesmacroscopiques, caractérisées par des propriétésexotiques et non-conventionnelles, estd’importance fondamentale dans la physiquemoderne. Ces états offrent des perspectivesfascinantes dans le domaine de traitementd’information, de simulations quantiques et derecherche des nouveaux types des matériaux.Dans ce travail de thèse nous développons unethéorie qui permet de décrire des phases non conventionnellesdans des systèmes des gazultra-froids dipolaires. Ces systèmes sontactivement étudiés expérimentalement enutilisant des atomes à grand-spins, desmolécules polaires et des excitations dipolairesdans des semi-conducteurs. Nous mettonsl'accent sur la révélation du rôle de l’interactiondipôle-dipôle à long porté.Nous considérons l’effet de rotonization dansun système de gaz des bosons dipolaires «tiltés»aux interactions faibles dans une couchehomogène. Nous prédisons l’effet derotonization pour un gaz de Bose faiblementcorrélé des excitons dipolaires dans une couchede semi-conducteur et nous calculons lediagramme de stabilité. Ensuite, nousconsidérons des superfluides d’onde-p desfermions identiques dans des réseaux 2D.Finalement, nous faisons une discussion sur unautre état superfluide intéressant des moléculespolaires fermioniques, qui devrait apparaitredans des systèmes bicouches. / The problem of revealing anddescribing novel macroscopic quantum statescharacter- ized by exotic and non-conventionalproperties is of fundamental importance formodern physics. Such states offer fascinatingprospects for potential applications in quantumin- formation processing, quantum simulation,and material research. In the present Thesis wedevelop a theory for describing nonconventionalphases of ultracold dipolar gases.The related systems of large-spin atoms, polarmolecules, and dipolar excitons in semiconductorsare actively studied in experiments.We put the main emphasis on revealing the roleof the long-range character of the dipole-dipoleinteraction.We consider the effect of rotonization for a 2Dweakly interacting gas of tilted dipolar bosonsin a homogeneous layer. We predict the effectof rotonization for a weakly correlated Bosegas of dipolar excitons in a semiconductorlayer and calculate the stability diagram. Wethen consider p-wave superfluids of identicalfermions in 2D lattices. Finally, we discussanother interesting novel superfluid offermionic polar molecules
4

Návrh řízení všesměrového mobilního robotu O3-X / Design of omni directional mobile robot (O3-X) control

Olša, Petr January 2010 (has links)
This thesis deals with the design of a three-wheeled omni-directional robot control. The model of control is designed for robot´s omni-directional platform driven by maxon motor with the intelligent positioning controller EPOS. The design of control contains: - installation of the coordinated systems and transformation from one of them into another - design of system´s kinematical model - creation of classes for control and communication with EPOS - creation of the simulative program - planning of the mobile robot´s path - verification that the system is working The solution was based on continuous accelerated motion and the maximal acceleration of wheels was concerned, so that the slip would be suppressed. The function of the model was partly verified.
5

Outcome of total Achilles tendon rupture repair, with special reference to suture materials and postoperative treatment

Kangas, J. (Jarmo) 24 April 2007 (has links)
Abstract The purposes of the present research were to compare the outcome after Achilles tendon rupture repair in two postoperative regimens, to compare Achilles tendon elongation in two postoperative treatment methods, to compare the effects of two postoperative methods on motor performance aspects such as simple reaction time, choice reaction time, speed of movement, foot tapping speed and coordination, to test the mechanical properties of the recently developed poly-L/D-lactide (PLDLA) sutures and Maxon® sutures when implanted in the Achilles tendons of rabbits, and to study the histological tissue reactions and biodegradation of these sutures under the same conditions. Isokinetic calf muscle strength scores at the last control check-up were excellent in 56% of the patients in the early motion group, good in 32%, fair in 8%, and poor in 4%, whereas the scores in the cast group were excellent in 29% of cases, good in 50% and fair in 21%. The ankle performance scores were excellent or good in 88% of the patients in the early motion group, fair in 4% and poor in 8%, whereas the scores in the cast group were excellent or good in 92% of cases and fair in 8%. No significant differences were seen between the two groups at 3 months and at the last control checkups with regard to pain, stiffness, subjective calf muscle weakness, footwear restrictions, range of ankle motion, isokinetic calf muscle strength or overall outcome. The complications included 1 re-rupture in the early motion group and 1 deep infection and 2 re-ruptures in the cast group. AT elongation occurred in both groups, but was somewhat less marked in the early motion group. The AT elongation curves rose at first and then fell slowly in both groups. The patients who had less AT elongation achieved a better clinical outcome. AT elongation did not correlate significantly with age, body mass index or isokinetic peak torques. The recovery of motor performance functions such as simple reaction time, choice reaction time, speed of movement, foot tapping speed and coordination did not depend on the two postoperative regimens. The motor functions of the operated leg had obviously recovered to the level of the non-operated leg 12 weeks after the operation. Sutures made of PLDLA were used successfully for Achilles tendon repair in rabbits. There was no significant difference between the in vitro and in vivo tensile strength retention of the sutures. By comparison with Maxon®, PLDLA was found to have a lower initial tensile strength but more prolonged strength retention. The breaking strength values of the Achilles tendons repaired with sutures of these types were not significantly different at 6 weeks. Intratendinous PLDLA sutures formed a thinner fibrous capsule during the 12-week follow-up period than did Maxon® sutures of the same diameter. The suture materials had not been totally absorbed by 12 weeks.
6

Pohon EC motoru malého výkonu / Low power BLDC electric drive

Štajner, David January 2017 (has links)
The aim of this diploma thesis is to introduce a construction and controlling of the EC motor. On a base of knowledge make up a EC motor model in Matlab Simulink, with a position scanning providing by Hall probe. The EC motor model should be with its behavior close to the real EC motor as much as possible. There were a given requirements on the motor. On the base of those requirements was chosen a real EC motor. Its catalog values were put in the EC motor model in Matlab and the results were compared with real data. Next task was to design a real controlling driver of EC motor, which should has a minimal size. This driver was constructed and thermal test was made a on given load.
7

Control of Double Inverted Pendulum First Approach

DABRETAU, Teerapong, DAREINI, Ali January 2015 (has links)
An Inverted double pendulum is a combination of two individual pendulums which represents an example of a nonlinear and unstable dynamic system and it is also a good example of a physical system which can exhibit chaotic behavior.This document contains a first analysis of the model and the control of this system. Also presented is the installation of the electrical materials needed to control the system contain instrumenting the motor, current measurement system, motor shaft angle sensor, vision systemand MYRIO which is an embedded hardware device created by National Instruments will be used for data acquisition and control the system
8

Propulsion Unit of a 3DOF Helicopter

Ling, Gustav, Persson, Jesper January 2015 (has links)
This Bachelor thesis is a part of a bachelor project which includes building, programming and controlling a 3DOF tandem helicopter. This particular report deals with the propulsion units, i.e. the motors and propellers of the helicopter. It covers the process of how to determine the most suitable propulsion units for the rig that eventually will enable it to run. To achieve this, different data have been processed. Torque and thrust are two important parameters that have been studied. The data have been acquired by different tests, e.g. thrust measurements from a thrust rig. Also more complex analysis such as Blade Element Theory and Actuator Disk Theory have been carried out in order to determine the behaviour of the propulsion units. Study data sheets and databases was also a part of the work. The result of this work was two equal propulsion units which were mounted in the helicopter. They proved to work satisfactory and provided wanted dynamics to the system. / Design & Implementation of a 3DOF Helicopter
9

Programování dvouosého pohonu s EC motory typu Maxon / Programming of the two-axle drive with Maxon EC motors

Toman, Jiří January 2008 (has links)
This work describes direction of the two-axle drive with EC motors type MAXON by means of control unit EPOS. Except own direction of EC motors it contains various types progress for proposal parameters of the continuous and discrete regulator with consequence verification and character comparison by means of programming surroundings MATLAB. After the successful simulation verification is introduced most suitable regulator for positional direction of the two-axle drive into the real control units EPOS which they are connected to EC motors MAXON with making sign EC- max 22. Further is realized communication setting among control unit type EPOS P and her subjection unit EPOS. Unit EPOS P is further connected with steering computer by means of serial bus RS 232. Other part these work is program for direction of the two-axle drive copying the inscription MAXON with use linear and circular interpolation. To creation of the program source code is used standard programming language ST. This program is realized in programming surroundings EPOS STUDIO which is added by the producer to control units EPOS.
10

Pokročilé plánování cesty robotu (RRT) / Advanced Robot Path Planning (RRT)

Knispel, Lukáš January 2012 (has links)
Tato diplomová práce práce se zabývá plánováním cesty všesměrového mobilního robotu pomocí algoritmu RRT (Rapidly-exploring Random Tree – Rychle rostoucí náhodný strom). Teoretická část popisuje základní algoritmy plánování cesty a prezentuje bližší pohled na RRT a jeho potenciál. Praktická část práce řeší návrh a tvorbu v zásadě multiplatformní C++ aplikace v prostředí Windows 7 za použití aplikačního frameworku Qt 4.8.0, která implementuje pokročilé RRT algoritmy s parametrizovatelným řešičem a speciálním dávkovým režimem. Tento mód slouží k testování efektivnosti nastavení řešiče pro dané úlohy a je založen na post-processingu a vizualizaci výstupu měřených úloh pomocí jazyka Python. Vypočtené cesty mohou být vylepšeny pomocí zkracovacích algoritmů a výsledná trajektorie odeslána do pohonů Maxon Compact Drive všesměrové mobilní platformy pomocí CANopen. Aplikace klade důraz na moderní grafické uživatelské rozhraní se spolehlivým a výkonným 2D grafickým engine.

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