Chemical Engineering

In present days, the development and applications of unconventional machining processes got rapidly increased in modern industries. The quality and performance of the product are improved through unconventional machining processes. Hard materials are preferred to obtain high dimensional accuracy. The machining of complex shapes, super finishing, micro machining and surface is possible by unconventional machining process. The efficiency of production and machining precision were enhanced. The different types of machining methods were utilized to remove the materials. The different metal removal parameter such as erosion, Ionic dissolution, vaporization were analysed etc. The medium of energy were been transferred through electrolyte, electron and high voltage particles. This review article clearly describes the unconventional machining and hybrid machining processes on different materials.

ACKNOWLEDGEMENT First of all we would like to thank the almighty GOD who helped us to make this paper work to be possible. This study work is realized with help of many hands together. However, since it is impossible to name all, we mentioned only the pillars with great excuse not to cite others. Let's our dearest gratitude goes to our advisor lecturer Ashenafi Shiferaw for their unlimited assistance and advises which made this paper work realizable. The last but not the least lets our special thanks reach our parents for their support and encouragement from the commencement to end of our education life. We also owe heartfelt gratitude to Bule Hora University and department of chemical engineering for patting trust and confidence on our work and for the feedback and encouragement since the beginning of the project. Lastly our department staffs deserve gratified thanks and respect for everything.

The determination of the caffeine content of coffee beans is the most popular way to solve the problem related to the level caffeine in coffee. In the present study, the caffeine level of Guji coffee beans was determined using the UltraViolet visible spectrometer Analysis Method. The coffee samples were collected from the coffee supplier farmer cooperatives union in Bule Hora. The sample was roasted and grinding using grinding for caffeine extraction. The obtained data by the study were compared with the caffeine levels that determined by different researchers from different selected sites, and indicates that the values of the results ranged from (1.04 ±0.0010 to 1.31±0.0021)% using ultraviolet-visible. The levels of caffeine from Hambella Wammana (1.31 ±0.0020)% was high, and that of Kercha (1.04 ±0.0010)% is low, and claimed that the caffeine levels of coffee beans of the same species that growth on different regions were varied due to different vital factors that influences amount caffeine in coffee beans. Generally, the study demonstrated that the caffeine level from selected areas of Guji Zone confirms the caffeine level of arabica coffee informed by the literature.

Nowadays, the utilization of synthetic fertilizer has significant adverse effects on the soil, ecosystem, and human health. To evade the use of synthetic fertilizers, the production of organic fertilizer from organic matter particularly from keratin-based materials, has become more popular as a way to solve the problems related to soil conditioning and human health. In addition, the impact of different methods on the extraction of organic fertilizer from keratin-based materials is discussed. Hence, the review was conducted to assess the effect of different methods like acid hydrolysis, base hydrolysis, and hydrothermal treatment on organic fertilizer extraction from keratin materials. Therefore, this revised seminar currently, as it deters the environmental pollution caused by chemical hydrolysis and hydrothermal treatment, the microbial fermentation by immobilized cell for organic fertilizer production is essential to enhancing a green environment and avoiding the risks related to human health.