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.

Preparation of Eco-Friendly Leather by Process Modifications to Make Pollution Free Tanneries

Abstract: The term “eco friendly” leather meant the “chrome free” leather. Around 80% of leather is tanned using chromium. The chromium used in the tannery may be in the form of chromium III, IV and chromium VI compounds. The chromium tanned leathers use chromium III salts (Trivalent chromium) in the form of chromium sulfate. This form of chromium is found naturally in the environment and is necessary nutrient for the human body. However the chromium III oxidizes to chromium VI (Hexavalent chromium) in the presence of oxygen combined with other factors, such as extremes in pH. This happens during the tanning process. The hexavalent chromium produces allergic reaction and easily moves across the membranes such as skin, and it is a major cause for many diseases. This research work suggests using silicate tanning process by eliminating the chrome tanning process to make eco friendly leather. The present tanneries which use chrome tanning process can be modified in to silicate tanning process to make pollution free tanneries and the future generations can be protected from very dangerous environmental impacts caused by chromium compounds.

The performance of true seed shallot lines under different environments of Ethiopia.

Abstract: Seven true seed shallot lines were evaluated for 3 years at 3 locations to determine their performance and stability. Stability differences were assessed on the basis of linear regression of the lines on environmental index and on deviation from linear function along with the mean yield. The combined analysis showed that bulb yield over 9 environments ranged from 15.1 to 17.5 t ha-1 with overall mean yield of 16.5 t ha-1, and lines Vethalam, Tropix, Dz-94 and Athlas gave the highest mean yield. The combined analysis of variance showed significant (p<0.05) genotype and genotype by environment effects on bulb yield. The regression coefficient for bulb yield ranged from 0.72 to 1.36. The regression coefficient of two high yielding lines (Vethalam and Athlas) was above 1, and was higher in environments where growing conditions were favorable. High and significant deviations were obtained for lines Tropix and Athlas and these lines were found unstable to change in environment. However, line Tropix showed specific adaptation to low yielding environments of Kulumsa and Melkassa. The best line Vethalam with a small deviation from regression was found widely adaptable to different environments and it was released with local name ‛Yeras’ to be grown in Rift Valley and similar areas in Ethiopia.

Pest control using farming awareness: Impact of time delays and optimal use of biopesticides

Abstract: We investigate a mathematical model in crop pest management, considering plant biomass, pest, and the effect of farming awareness. The pest population is divided into two compartments: susceptible pest and infected pest. We assume that the growth rate of self-aware people is proportional to the density of healthy pests present in the crop field. Impacts of awareness is modeled via a saturated term. It is further assumed that self-aware people will adopt biological control methods, namely integrated pest management. Susceptible pests are detrimental to crops and, moreover, there may be some time delay in measuring the healthy pests in the crop field. A time delay may also take place while becoming aware of the control strategies or taking necessary steps to control the pest attack. In agreement, we develop our model incorporating two time delays into the system. The existence and the stability criteria of the equilibria are obtained in terms of the basic reproduction number and time delays. Stability switches occur through Hopf-bifurcation when time delays cross critical values. Optimal control theory has been applied for the cost-effectiveness of the delayed system. Numerical simulations illustrate the obtained analytical results.