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Although there have been many studies published in the field of simulating and predicting surface roughness of machining processes, they are chiefly related to turning and milling operations, and the number of studies concerning the internal turning process is excessively limited. Furthermore, the existing publications in this field have mostly implemented statistical approaches which not only lack generalizability, but also require a huge number of experiments. In the current research, a simulation method of surface roughness is developed by using kinematics and dynamics of the process. Despite the numerous applications of this approach in turning operations, it has not yet been used in the internal turning processes. The first stage of this approach is to measure the insert nose profile of the tool. Then, the surface profile consisting the periodical component of feed marks should get constructed. In the next step, the vibrations imposed by the long boring bar are measured by an accelerometer. In order to factor in the effect of vibration on the final profile, the recorded vibrations should then get twice integrated to attain the displacement signal and added to the periodical component of the roughness profile. Results obtained from internal turning experiments in order to validate this method revealed that the developed simulation approach has a maximum error of 19.3% in estimating roughness parameters which can be presumed as accurate enough. [ABSTRACT FROM AUTHOR]

Sheep tail fat is a suitable frying oil due to its good flavor and oxidation stability. This oil with its useful fatty acids can to play beneficial effect on consumer health. The refining processes of sheep tail oil, including its deodorization have high importance in the enhancement of the oil quality. Deodorization is a separation process in which a certain amount of the volatile compounds separator gas passes through the hot oil under vacuum condition and removes the volatile and odorous compounds from the oil. In this study, the ultrasound-assisted deodorization of sheep tail fat was carried out and the effects of temperature, time, and ultrasonic power on odor intensity during the deodorization process were investigated using the response surface methodology. The intensity of the odor was assessed by electronic nose and sensorial evaluation. Also, the fatty acid composition was compared before and after the deodorization process. The results of fatty acids profile showed that about 46.72% of sheep tail oil fatty acids were saturated fatty acids (palmitic, stearic, margaric, and myristic) and the rest (53.28%) was unsaturated fatty acids, which the majority of them was oleic acid (39.67%). According to the results of analysis of variance, the composition and kind of the fatty acids before and after the deodorization were close together and the amount of fatty acids changed slightly during the deodorization. Finally, the optimized conditions at the temperature of 162 °C, the time of 110 min and the ultrasonic power of 165 W were determined using electronic nose and sensory evaluation for ultrasound-assisted deodorization of sheep tail oil. [ABSTRACT FROM AUTHOR]