Yazar "Ozguven, O. F." seçeneğine göre listele

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    Effect of some heating parameters on volume expansion of borax
    (Soc Mining Metallurgy Exploration Inc, 2008) Kahraman, B.; Ozel, M.; Ozguven, O. F.; Batar, T.; Erdogan, N.; Dicle, Z.; Safak, S.
    About 70% of the world's total boron reserves are located in Turkey. Boron minerals are typically concentrated by attrition scrubbing followed by screening and classification to remove clay minerals and other impurities. These wet concentration methods, however, result in a considerable amount of accumulated tailings in large tailings dams. The tailings are approximately 28% solids and contain 14% B(2)O(3). Problems caused by these tailings can be minimized by employing dry beneficiation techniques involving heat treatment. This method has been successfully tested on laboratory, and pilot scales. During heat treatment, borax undergoes expansion in volume. The amount of expansion is dependent on the particle size, temperature and duration of heat treatment. Because the optimum temperature and the duration of the heat treatment are not well defined, the boron ore acts as a calcined clay mineral and is discarded along with the gangue. It is important to predict such parameters using mathematical formulations. Thus, a mathematical model is used to predict the required temperature and duration period prior to heat treatment. In the experimental study presented here, a series of systematic thermal tests was carried out in a muffle furnace. Two variables, temperature and time, were studied in a response surface design. A quadratic regression model was chosen and regression coefficients were calculated. Using a regression equation, the volume expansion of the particles in various circumstances can be predicted. The mathematical test results are then correlated with the experimental results to relate the optimum expansion of borax with heating time and temperature and with borax grades and recoveries.
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    A New Method to Separate Broken Rotor Failures and Low Frequency Load Oscillations in Three-Phase Induction Motor
    (Ieee, 2013) Goktas, T.; Arkan, M.; Ozguven, O. F.
    For a time-varying loads, the presence of load fluctuation may sometimes have the same effect as broken rotor failure in a stator current of induction motors. In recent years, many methods, which are used to distinguish these two effects, have been published. In this study, a new method, which is based on Analytical Signal Angular Fluctuation (ASAF) signal, is developed to separate effects of load oscillation from broken rotor bar, especially when load oscillation is close to twice slip frequency. The simulation results are presented for the proposed method to show that, discerning broken rotor bar faults from low frequency load oscillation is possible. The developed method is independent of motor parameters.