http://etd.aau.edu.et:80/dspace/handle/123456789/500 Search the Channel search http://etd.aau.edu.et:80/dspace/simple-search http://etd.aau.edu.et:80/dspace/handle/123456789/2606 Title: DETERMINATION OF OPTIMUM CONDITION FOR THE PRODUCTION OF COMMERCIALLY VIABLE GLUE FROM TANNERY SOLID WASTE <br/> <br/>Authors: Hanna, Berhanu <br/> <br/>Abstract: Glues are an adhesive which are collected by persistent boiling of animal skin, hide trimmings and flesh from the slaughter houses. They can also be gathered from the scrap of animal skin and hide residues of leather industry. This study was aimed at determining the optimum condition for the production of high quality glue from tannery solid waste. In other word, the effect of type of reagents used (such as lime and sulfuric acid), concentration of reagents, boiling time, soaking time and boiling temperature were investigated. The pelt was treated with 2.5% and 10 % concentration of reagents. Under sulfuric acid solution the pelt was soaked overnight and boiled for 2 and 4 hrs at 70oC and 80oC, whereas it was kept for 2 and 4 weeks under lime solution and boiled for about 4 hrs at 70oC and 80oC. Generally, the glue produced by using lime showed relatively high quality than the one produced from sulfuric acid. It was possible to extract high amount of glue within a short period of time from sulfuric acid treated pelt as compared to lime treated one. Under lime medium, the adhesive strength of glue was increased with the concentration and soaking time and decrease with temperature. Soaking of the pelt, in 10% lime solution, for 4 weeks and boiling at 70oC were found to be the optimum conditions for the production of commercially viable glue. At this condition, the viscosity, yield and mass of residue was 255.05 mP, 0.1357g / g of pelt and 0.32287 g/ g of pelt, respectively. The economic feasibility study, carried out in this work, showed that the project is to be financially viable with the rate of return of the project 27.9%, the payback period of 3.08 year and the net present value of 40,036,155.25 birr. Fri, 04 May 2012 16:40:56 GMT http://etd.aau.edu.et:80/dspace/handle/123456789/1502 Title: Analysis of Fillers for Production of Alternative Building Materials Using Magnesia Cement <br/> <br/>Authors: Tamrat Tadele <br/> <br/>Abstract: Fillers, which are available in the country, are essential for the production of magnesia cement boards. These include pumice and lignocellulostic fillers such as bagasse, sawdust and coffee husk. While applying these fillers to produce the boards, their nature and performance should be studied. Magnesia cement was used as binding materials; varying boards were produced for different proportion fillers with fixed ratio of magnesium oxide and magnesium chloride. For the board produced, density, water absorption, and setting time as well as mechanical properties such as the compressive strength and the bending strength determined. In addition, the effects of different fillers on the properties of the board and production cost were examined. When the saw dust and coffee husk filler substituted the current used bagasse filler, the water absorption and setting time of the boards reduced. While the density, bending strength and compressive strength of the board increased. The mix ratio of fillers and pumice powder had also influence on the physical and mechanical property of the boards. The test results showed as the proportion of the pumice increased, the mechanical strength of the boards increased and the setting time of the cement paste reduced. The cost analysis showed that the saw dust board production cost was lower than coffee husk and bagasse board cost. While the production cost of the coffee husk board was slightly higher than others.In aim of production of filler boards as alternative building materials are, the cost comparison showed in the possibility of producing relatively low price than the hollow concrete blocks included finishing work cost. <br/> <br/>Description: A Thesis Submitted to the School of Graduate Studies of Addis Ababa University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Process Engineering Sat, 18 Oct 2008 07:25:46 GMT