Adama University

About: Adama University is a education organization based out in Nazrēt, Ethiopia. It is known for research contribution in the topics: Population & Adsorption. The organization has 840 authors who have published 1010 publications receiving 5547 citations. The organization is also known as: Adama Science and Technology University & ቴክኖሎጂ ዩኒቨርሲቲ, አዳማ ሳይንስና ቴክኖሎጂ ዩኒቨርሲቲ.

Physical stabilization of expansive subgrade soil using locally produced geogrid material

Abstract: This paper illustrates application of a locally produced geogrid material for strength improvement of expansive subgrade soil. Samples of black, soft soil predominating the study area were collected from south western parts of Modjo town, inside the rift valley region of central parts of Ethiopia. X-Ray diffraction as well as index property tests were executed to identify and categorize the expansiveness of the highly plastic soft soil. The effects of two locally manufactured geogrid reinforcement materials; namely, polypropylene (PP) and high density polyethylene (HDPE) on the California bearing ratio (CBR) values of the expansive soil have been investigated. The test results indicated that the use of the geogrid reinforcement can significantly improve the bearing capacity of weak subgrade soil. The soaked CBR of the untreated soil sample, which was about 2.98%, was able to be raised to 10.16% and 7.48% by the application of PP and HDPE type of geogrid respectively, that were placed at 0.35H from the top of specimen. The research demonstrated the potential of using locally produced geogrid material for the improvement of weak subgrade soil.

Design Analysis and Modification of Sugarcane Fibrizer Hammer at Wonji Shoa Sugar Factory (WSSF) Ethiopia

Abstract: Wonji Shoa Sugar Factory (WSSF) is one of the top sugar factories in Ethiopia which produces sugar and electricity from sugarcane using three critical plants: mill plants, sugar processing plant, and a cogenerating power plant. Among three plants, the mill plant is the most important plant used to crush the cane for separating sugar juice from bagasse. In this plant, Fibrizer hammer device is used for cruising sugarcane. The Fibrizer performs the major share in milling process for fibrizing the chopped cane after set of cane knives using rotating knives. Most of the times, WSSF is facing breakages of Fibrizer hammer by which losses incurring to the factory. The main aim of the paper is to analyze the failure causes of existing Fibrizer hammer with respect to design and modify the necessary changes in design for Fibrizer hammer at WSSF. By which, get high preparation index (PI) and optimize in power consumption and cost. In addition, hardness of the existing Fibrizer hammer was tested to know the mechanical strength. For modification of existing Fibrizer hammer: comparison was made in terms of design, and load along with harmonic simulation analyses performed using finite element analysis. The results from finite element analysis revealed that the modified Fibrizer hammer having minimum deformation, minimum shear stress, and more centrifugal force has a relation to achieve better preparation index.

Production and Purification of Biogas Generated by Co-digestion of Cow Dung and Kitchen Waste

Abstract: This study was designed to produce biogas from co-digestion of cow dung and kitchen waste. 20 litres digester and gas collection systems were prepared from locally available materials. The feed materials were collected locally, pre-fermented, digested and analysed. Purification of the produced biogas was carried out by passing the gas through three chambers containing 40% KOH, CaO. activated charcoal and silica gel/activated charcoal respectively. The flame of the combusting purified biogas was observed to be more intense than that of the freshly produced impure biogas both in colour and height. The study confirmed that biogas can easily be generated and purified using locally and cheaply available raw materials