Thesis (MScIng)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Thesis (MEng.) -- Stellenbosch University, 1997. / One copy microfiche. / ENGLISH ABSTRACT: This thesis desc1ibes the procedure followed in order to establish geometry changes to the current lig!1tweight dragline bucket lmilt by Wright Equipment Compan:Y to improve its performance. The bucket performs very well as is and big changes v , e not expected. This project was done as part of the Mechanical Engineering Masterr- Jegree requirements at the University of Stellenbosch, while being employed by Wriglh Equipment A scale model dragline was designed and built to be used in collecting the data. The most significant variables when considering dragline bucket filling were established and ranked according to their relative influence. The tests were done, using four different scale model dragline buckets and changing a 11umber of variables on each of them at different drag angles and in different digging conditions. Eventually it was found that a shorter, wider bucket with a lower hitch, resulted in improved performance as far as filling distance and filling energy requirements were concerned. The maximum required drag force was not increased, meaning stalling of the bucket would not be a problem. The changes do have some structural implications though aud should be investigated before any changes are made. / AFRIKAANSE OPSOMMING: Die tesis be£kryf die prosedure wat gevolg is om geometrie veranderinge aan die liggewig sleepgraatbak, wat deur die maatskappy Wright Equipment vervaardig word, te ondersoek. Die uiteindelike doel was om di~ produktiwiteit van die bak (gedefinieer as die hoeveel bogrond wat in 'n gegewe tyd geskuif word} te verbeter Die projek het deel gevorm van die vereistes vir 'n Meestersgraad in Meganiese lngenieurswese by die Universiteit van Stellenbosch. 'n Skaalmodel sleepgraaf is ontwerp en gebou vir gebruik in die versameling van die nodige data. Die belangrikste faktore betrokke by die vulling van sleepgraatbakke is vasgestel en in rangorde van belangrikheid gegroepeer. Vier skaalmodel sleepgraatbakke, waarop verskillende geometriese veranderinge gedoen kon word, is gebruik in toetse teen verskillendt sleephoeke en grondkondisies. Daar is gevind dat 'n korter, wyer bak met 'n laer sleeppUt"'t '1. v~rbetering in werkverrigting gee in terme van afstand om te vul en energie ve1·t.· :•.• Die maksimum sleepkrag benodig is ook nie verhoog nie, met die gevolg dat str:, l,' nie 'n probleeill sal wees me. Die voorgestelde veranderinge het egter struk.i.t..•' ic imt"i'---dsies wat eers ondersoek sal moet word voor enige veranderinge gedoen word.

No description available.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2007. / Dragline bucket designers are required to evaluate new bucket designs by building and testing scale buckets. Concerns about the reliability and accuracy of scale testing have been raised in recent years, but there was no alternative. However, recent advances in computing power and granular flow modeling are changing this and, we are entering an era where it is possible to numerically simulate dragline bucket filling. However, verification of the numerical simulation is necessary before useable data can be obtained. This thesis explains the algorithm used by modern discrete element codes to simulate granular materials. The process used to create the numerical model and calibrate the material will be discussed. An experimental test bench was also built to record experimental data for the verification the numerical model. As the project progressed it became clear that the time needed to run a single simulation dramatically limits the number of simulations that could be run. Consequently, different approaches that could reduce simulation time were also investigated. Unlike the other material parameters, there is no test that can be used to directly calibrate the damping. An array of numerical simulations were therefore conducted testing different damping schemes. The comparison performed between the numerical and experimental data showed that the numerical models could not accurately simulate the experimental measurements of the scale model dragline bucket. The numerical model did, however, predict many of the trends identified in the experimental simulation. With more realistic contact models and better computer facilities, nonetheless, it is highly probable that numerical models will be capable of simulating dragline bucket filling accurately. Further study is, therefore, justified.

Thesis (MEng) -- Stellenbosch University, 2000. / ENGLISH ABSTRACT: The utilisation ofDraglines to remove overburden in surface mining operations is often the process that determines the output of these operations. The bucket and its rigging have been identified as important components where design changes can improve the efficiency of the dragline. It is necessary to create a method to predict the dynamic behaviour of the bucket when various design changes are made to the rigging and the bucket. A rigid multibody dynamic method is formulated that can be used to predict the behaviour of any physical system that can be modelled as a set of connected rigid bodies. This multibody method is verified with analytic test problems and an experiment. A description is given how to use this rigid multibody dynamic method to model the dragline and predict the behaviour ofthe bucket during an operational cycle. / AFRIKAANSE OPSOMMING: Sleepgrawe word gebruik in oppervlakmynbouaktiwiteite om die mineraal neerslae wat ontgin word te ontbloot. Hierdie proses bepaal baie keer die produksie van die mynbou aktiwiteit. Die sleepgraaf se bak en die takelwerk van die bak het 'n groot invloed op die sleepgraaf se werksverrigting. Om die bak se werksverrigting te verbeter is 'n metode nodig om die dinamiese gedrag van die bak te voorspel. In hierdie dokument word 'n metode beskryf waarmee die dinamiese gedrag van enige stelsel bepaal kan word, wat as 'n stelsel van onderling-verbinde onbuigbare liggame beskryf kan word. Die korrektheid van hierdie metode is getoets met behulp van analitiese sowel as eksperimentele metodes. Daar word ook 'n beskrywing gegee hoe hierdie metode gebruik kan word om die beweging van die bak tydens 'n tipiese werksiklus te voorspel.

Das Thema der vorgelegten Dissertation ist der quasi-isochrone Betrieb der Metrology Light Source zur Erzeugung kurzer Elektronenpakete mit der damit verbundenen Emission von kohärenter Sychrotronstrahlung. Die Metrology Light Source wurde schon in der Planungsphase auf den quasi-isochronen Betrieb ausgelegt. Es stehen Quadrupol-, Sextupol- und Oktupolmagnete zur Verfügung, um die drei führenden Ordnungen des sogenannten momentum compaction factors zu kontrollieren. Der Schwerpunkte der Arbeit ist nichtlineare, longitudinale Strahldynamik, insbesondere die sogenannten "alpha-buckets". Der Vergleich zwischen analytischen Ansätzen, numerischen Simulation und experimentellen Daten wird vorgestellt und diskutiert. Desweiteren wurde die Stromlimitierung durch die Bursting-Instabilität an der Metrology Light Source untersucht. Der Großteil der Messungen ist dabei an der Metrology Light Source durchgeführt worden mit komplementären Messungen am Elektronenspeicherring BESSY II. / The subject of this thesis is the operation of an electron storage ring at a low momentum compaction to generate short electron bunches as a source for coherent synchrotron radiation. For this purpose the Metrology Light Source is ideally suited, as it is the first light source designed with the ability to adjust the three leading orders of the momentum compaction factor by quadrupole, sextupole and octupole magnets. Therefore, new opportunities to shape the longitudinal phase space arise. Focus will be put on beam dynamics dominated by nonlinear momentum compaction, in particular the generation of a new bucket type "alpha-buckets" and possible applications. Relation of analytical theory, numerical simulations and experimental data will be presented and discussed. In addition, the current limitation due to the bursting instability at the Metrology Light Source bunches will be investigated. The majority of measurements were conducted at the Metrology Light Source complemented by measurements at the BESSY II storage ring.

This master’s thesis deals with the construction of parts of a bucket-wheel stacker/reclaimer designed to operate lignite stockyard at coal power plant. First the basic parameters of machine and loads applied in service are defined. The work also includes the design of steel structure of bucket-wheel boom, bucket-wheel, buckets, bucket-wheel drive, shaft, bearings and other parts of bucket-wheel boom. These parts are verified by analytical or finite element analysis.

Die steigende Nachfrage nach Synchrotronstrahlungsanlagen hat zu einem stetig wachsenden Angebot auf der ganzen Welt geführt. Die wissenschaftliche Nutzergemeinde der Speicherring-basierten Lichtquellen benötigt immer höhere Brightness und viele sind auch an speziellen Zeitstrukturen der Strahlung, wie kurzen Pulslängen und bestimmten Wiederholungsraten, interessiert. Dies hat zu einer kontinuierlichen Verbesserung bestehender und zum Bau vieler neuer Anlagen geführt. Das Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB) betreibt den Berlin Electron Storage Ring Society for SYnchrotron Radiation (BESSY) II, eine Lichtquelle dritter Generation. Der Betrieb der Speicherring basierten Lichtquelle BESSY II nahe der transversalen, optischen Resonanz dritter Ordnung mit Transverse Resonance Island Buckets (TRIBs) Optik ermöglicht die Speicherung von Strom auf einer zweiten, stabilen Umlaufbahn. Der zweite Orbit windet sich im transversalen x-x′-Phasenraum über drei Umläufe um den Kernorbit und hat somit etwa den dreifachen Arbeitspunkt des Kernstrahls. Der stabile Inselorbit bietet die Möglichkeit, die Elektronen für jeden der 400, von der 500 MHz BESSY II Radio Frequency (RF) Kavität definierten, Buckets, fast beliebig zwischen dem Kern und den drei zugehörigen TRIBs zu verteilen. Dies eröffnet neue Möglichkeiten der Bunchtrennung. Durch Bevölkerung eines Orbits mit wenigen Elektronenpaketen, kann dieser dediziert für zeitaufgelöste Experimente genutzt werden. Es erhalten alle Strahlrohre mit hinreichender Akzeptanz die Möglichkeit, zeitaufgelöste Experimente durchzuführen. Die Bunchtrennung wird durch Ausrichtung der Strahlrohre auf den gewünschten Orbit erreicht. Somit stellt dieser Betriebsmodus eine Möglichkeit dar, die Timing-Fähigkeiten der BESSY II-Anlage und Speicherringbasierter Lichtquellen im Allgemeinen weiter auszubauen. / The increasing demand for synchrotron radiation facilities has led to a continuously increasing offer around the world. The scientific user community of storage-ring-based light sources requires ever-higher brightness and many are also interested in special time structures of the radiation such as short pulse lengths and certain repetition rates. This has led to continuous upgrades of existing and the construction of many new machines around the world. The Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB) operates the third generation light source Berlin Electron Storage Ring Society for SYnchrotron Radiation (BESSY) II. Operation of the storage-ring-based light source BESSY II in proximity of the third-order, transverse, optical tune resonance with Transverse Resonance Island Buckets (TRIBs) optics enables storage of current on a second stable orbit winding around the core orbit in the transverse x-x′ -phase space. This second orbit closes after three revolutions, resulting in a tune approximately three times that of the core tune. The stable island orbit provides the possibility to populate each of the 400 Radio Frequency (RF) buckets, defined by the 500 MHz cavities at BESSY II not only on the core but also additionally or exclusively on one or all three of the corresponding transverse island buckets of the threefold island orbit. This provides unique bunch separation possibilities with the appropriate population of each orbit. The population of one orbit with single bunches enables dedicated utilisation of this orbit for timing experiments and gives all beamlines with sufficient acceptance access to time-resolved experiments. The bunch separation is realised by aligning each beamline with the desired orbit. Thus, this operation mode represents a possibility to enhance the timing capabilities at BESSY II and storage ring based light sources in general.

<p>Device Management Applications are applications which are used to manage software on devices such as mobile phones. OMSI Forum provides such an application which is used to update the software on a phone. Software updates can be done at device management stations placed in stores or other service locations. Whenever a phone's software is updated, information about the update process is stored in a log. These logs can then be analyzed to generate statistics about updates such as the number of successful or failed updates or which faults that are common.</p><p>This master thesis project solves the problem of manually collecting and compiling logs from several stores by making this process automatic. Rather than collecting logs manually, each device management station sends its logs to a centralized server which stores all collected logs in a database. This makes it possible to generate charts and statistics in a simple manner from a web application. This solution makes the analysis more e ective, allowing users to concentrate on analyzing data by removing the work task of collecting logs.</p>

Device Management Applications are applications which are used to manage software on devices such as mobile phones. OMSI Forum provides such an application which is used to update the software on a phone. Software updates can be done at device management stations placed in stores or other service locations. Whenever a phone's software is updated, information about the update process is stored in a log. These logs can then be analyzed to generate statistics about updates such as the number of successful or failed updates or which faults that are common. This master thesis project solves the problem of manually collecting and compiling logs from several stores by making this process automatic. Rather than collecting logs manually, each device management station sends its logs to a centralized server which stores all collected logs in a database. This makes it possible to generate charts and statistics in a simple manner from a web application. This solution makes the analysis more e ective, allowing users to concentrate on analyzing data by removing the work task of collecting logs.