ABSTRACT DEVELOPMENT OF A COMPUTER PROGRAM FOR FRICTION WINDING SYSTEM DESIGN &Uuml / nal, Fuat G&ouml / khan M.Sc., Department of Mining Engineering Supervisor: Prof. Dr. Naci B&ouml / l&uuml / kbasi September 2011, 99 pages As the trend to deeper mines continues, mine hoists and associated equipment will become more sophisticated, complex, large and expensive. Correct selection of the right type of hoist is imperative. In this vital link between underground and surface, crude estimates of hoist capacity are not good enough, and the mining engineer must design and select the right hoisting system to meet the design specifications and establish the most suitable operating parameters. This study aims to constitute a software model, which results all required design parameters of friction type winding system on minimum required power. The computer program has been structured on Microsoft Visual Basic programming language. The program requires user inputs (winding depth, hourly hoisting capacity) and selections (type and number of motors, type of friction wheel mounting) to run macros and equations so that the operating parameters such as skip capacity, rope type and diameter, hoisting speed, acceleration, cycle period, friction wheel diameter are determined to give the minimum motor power requirement.

This study combined photocatalytic technology with activated carbon cellulose-paper filter (ACCF) adsorption to decompose gaseous pollutants. Gaseous pollutants were initially adsorbed by activated carbon and could be further decomposed by photocatalytic technology. This study selected acetone (CH3COCH3) as gaseous pollutants. Two market available photocatalysts (photocatalysts¢¹and¢º) were coated on ACCF by impregnation to decompose acetone in a batch photocatlytic reactor. Operating parameters investigated in this study included initial acetone concentration (4.1~10.2 £gM), reaction temperature (40~70¢J), and water vapor (0~20 %). The incident UV light of 365 nm was irradiated by a 20-watt low-pressure mercury lamp placing above the batch photocatalytic reactor. The ACCF coated with TiO2 was placed at the center of the photocatalytic reactor. Acetone was injected into the reactor by a gasket syringe to conduct the photocatalytic tests. Reactants and products were analyzed quantitatively by a gas chromatography with an electron capture detector (GC/DCD) and a flame ionization detector followed by a methaneizer (GC/FID-Methaneizer). Finally, a Langmiur-Hinshewood (L-H) kinetic model was proposed to describe the rate of photocatalytic reaction. Results obtained from the photocatalytic tests indicated that photocatalyst¢º was better than photocatalyst¢¹ for the decomposition of acetone. Experimental results indicated that the size range of self-produced TiO2 photocatalyst by sol-gel was 20~70 nm. The end products were mainly CO and CO2, which resulted in the mineralization ratio up to 98%. Results obtained from the operating parameter tests revealed that the increase of initial acetone concentration enhanced the amount of acetone adsorbed on ACCF, which however did not increase the reaction rate of acetone. Although the increase of reaction temperature could reduce the amount of acetone adsorbed on ACCF, the decomposition rate of acetone could be promoted, so as the yield rate and mineralization ratio of products (CO and CO2). The increase of water vapor could slightly decrease the amount of acetone adsorbed on ACCF. The competitive adsorption phenomenon between acetone and water molecules on active sites could decelerate the decomposion of acetone. Moreover, the ACCF would not be saturated since the adsorbed acetone could be further decomposed quickly by the photocatalysts, which made the TiO2/ACCF more effective on removing acetone and lasted longer than the conventional ACCF. Finally, a modified bimolecular Langmuir-Hinshelwood kinetic model was developed to investigate the influences of initial acetone concentration reaction, temperature, and relative humidity on the promotion and inhibition for the photocatalytic oxidation of acetone. The modified L-H kinetic model could successfully simulate the photocatalytic reaction rate of acetone. Thus, the reaction rate of acetone over TiO2/ACCF could be described by the modified L-H kinetic model.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais / In recent years, the demand of the productive sector for more efficient processes has encouraged the research and development of products and processes to increase the production at a competitive cost. In this sense, the \"Plasma-MIG\" with Concentric Arcs process, being an evolution of the conventional MIG/MAG process, has emerged as a promising option. This process has been available to the market since the 70s. However, it is still necessary to consolidate a scientific and technological basis of that process. Only then the market will decide if it is applicable, either to replace or become an option instead of the other processes. Thus, the challenge is to collaborate with both the scientific and the production what actually is the overall goal of this work, that is to provide fundamental knowledge about functioning principles and operating parameters of the \"Plasma-MIG\" with Concentric Arcs. The influence of the gas flow, especially of the intermediate one on the weld bead surface appearance, the effect of external arc on the globular-spray transition current and on the axial spray-rotational transition current, as well as on the droplet kinematic parameters and the relation between the outer arc current/torch working angle/torch-piece distance and the weld geometry have been studied experimentally. The results showed that the intermediate arc gas flow rate was the very one which determined weld appearance. The globular-spray transition current rose and the axial spray-rotational transition current became lower in the presence of the outer arc. The presence of the outer arc also raised the momentum of the drops hitting the weld pool. The presence of current in the outer arc at low values reduces penetration and correlated parameters (either directly or inversely proportional), but causes their growing again when being increased. The bead geometry follows the similar behavior of the conventional MIG/MAG as regards to the torch working angle and the torch-piece distance, though being more intensified when using the outer arc. In conclusion, it is possible to say that the knowledge on the operational characteristics of the \"Plasma-MUG\" with Concentric Arcs welding process obtained in this work may serve as a basis for the perception of this process application potential. / Nos últimos anos, a demanda do setor produtivo por processos mais eficientes tem incentivado a pesquisa e o desenvolvimento de produtos e processos que permitam o aumento da produção a um custo compatível. Neste sentido, o processo de soldagem \"Plasma-MIG\" com Arcos Concêntricos, uma evolução do processo MIG/MAG convencional, tem surgido como uma opção promissora. Esse processo está à disposição do mercado desde a década de 70, no entanto, ainda é necessário consolidar uma base cientifica e tecnológica a respeito desse processo. Somente assim o mercado poderá decidir se o mesmo é aplicável, seja para substituir ou se tornar mais uma opção frente a outros processos. Desta forma, é no desafio de colaborar tanto com o meio cientifico como o produtivo que se enquadra o objetivo global deste trabalho, o qual é o de fornecer conhecimentos fundamentais sobre aspectos de funcionamento e parâmetros operacionais do processo \"Plasma-MIG\" com Arcos Concêntricos. Foram estudados experimentalmente a influência das vazões dos gases, principalmente o intermediário, sobre o aspecto superficial do cordão de solda, o efeito do arco externo sobre as correntes de transição globulargoticular e goticular axial-rotacional e sobre os parâmetros cinemáticos das gotas e a relação entre corrente do arco externo/ângulo de inclinação da tocha/distância da tocha a peça e a geometria do cordão. Os resultados apontam que a vazão governante sobre o acabamento do cordão é a do gás intermediário. A corrente de transição globular-goticular elevou-se e a goticular axial-rotacional ficou menor na presença do arco externo. A presença do arco externo também fez elevar o momentum das gotas atingindo a poça. A presença da corrente no arco externo em valores baixos reduz a penetração e parâmetros correlacionados (de forma direta ou inversamente proporcional), mas faz novamente crescêla ao ser aumentada. A geometria do cordão segue o comportamento similar ao do processo MIG/MAG convencional quanto ao ângulo de inclinação e distância da tocha à peça, mais intensificado quando se usa arco externo. Ao final, pode-se dizer que os conhecimentos gerados no presente trabalho sobre as características operacionais do processo \"Plasma- MIG\" com Arcos Concêntricos formam uma base para conceber a potencialidade aplicativa do processo. / Doutor em Engenharia Mecânica

Die quantitative Abschätzung des Einflusses geometrischer Abweichungen auf die Betriebseigenschaften von Maschinenelementen stellt für die Produktentwicklung einen wesentlichen Bestandteil zur Sicherung der Funktionalität dar. An einem radialen zylindrischen Gleitlager wird gezeigt, wie der Einfluss der Rundheit in Form eines Gleichdickes die Betriebsparameter verändert. Durch die Simulation mit ALP3T und die Auswertung der Ergebnisse mit MATLAB kann eine mögliche Vorgehensweise für den Umgang mit Formabweichungen bei der Entwicklung und der Qualitätssicherung aufgezeigt werden. Ferner gilt es andere geometrische Abweichungen (Position, Richtung) zu untersuchen, um die Funktionalität des Gesamtsystems sicherzustellen.

The aim of this thesis is an analysis of the construction of a trailer used for transporting concrete pillars. The main part of the thesis is focused on frame construction. For the calculation of load states a multi body system was used, whereby a simulation of transport in terrain was performed. The results from these calculations will be used as limiting conditions for strength control. The method of solution is the finite element method. All acquired results will be analysed and according to them changes will be made to the frame construction. In addition to this, the thesis contains drawings documenting the above-mentioned changes.