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.

Real Exchange Rate and Manufacturing Export Competitiveness in Eastern Africa

Abstract: This paper investigates the effects of real exchange rates on manufacturing exports in 10 East African countries. The study uses pooled mean group and...

Leverage of Environmental Pollutant Crump Rubber on the Dry Sliding Wear Response of Epoxy Composites.

Abstract: The effect of crump rubber on the dry sliding wear behavior of epoxy composites is investigated in the present study. Wear tests are carried out for three levels of crump rubber (10, 20, and 30 vol.%), normal applied load (30, 40, and 50 N), and sliding distance (1, 3, and 5 km). The wear behavior of crump rubber–epoxy composites is investigated against EN31 steel discs. The hybrid mathematical approach of Taguchi-coupled Grey Relational Analysis (GRA)—Principal Component Analysis (PCA) is used to examine the influence of crump rubber on the tribological response of composites. Mathematical and experimental results reveal that increasing crump rubber content reduces the wear rate of composites. Composites also show a significant decrease in specific wear values at higher applied loads. Furthermore, the coefficient of friction also shows a decreasing trend with an increase in crump rubber content, indicating the effectiveness of reinforcing crump rubber in a widely used epoxy matrix. Analysis of Variance (ANOVA) results also reveal that the crump rubber content in the composite is a significant parameter to influence the wear characteristic. The post-test temperature of discs increases with an increase in the applied load, while decreasing with an increase in filler loading. Worn surfaces are analyzed using scanning electron microscopy to understand structure–property correlations. Finally, existing studies available in the literature are compared with the wear data of the present study in the form of a property map.

Farming awareness based optimum interventions for crop pest control

Abstract: We develop a mathematical model, based on a system of ordinary differential equations, to the upshot of farming alertness in crop pest administration, bearing in mind plant biomass, pest, and level of control. Main qualitative analysis of the proposed mathematical model, akin to both pest-free and coexistence equilibrium points and stability analysis, is investigated. We show that all solutions of the model are positive and bounded with initial conditions in a certain significant set. The local stability of pest-free and coexistence equilibria is shown using the Routh-Hurwitz criterion. Moreover, we prove that when a threshold value is less than one, then the pest-free equilibrium is locally asymptotically stable. To get optimum interventions for crop pests, that is, to decrease the number of pests in the crop field, we apply optimal control theory and find the corresponding optimal controls. We establish existence of optimal controls and characterize them using Pontryagin's minimum principle. Finally, we make use of numerical simulations to illustrate the theoretical analysis of the proposed model, with and without control measures.

Urban green infrastructure accessibility for the achievement of SDG 11 in rapidly urbanizing cities of Ethiopia

Abstract: Rapid urban expansion across the globe has created enormous problems on human wellbeing and the environment. In this regard, urban green infrastructure has played a major role in improving the quality of life and is perceived as one of the vital instruments for attaining sustainable development goals. Yet, the issue of access to green spaces is one of the crucial aspects of sustainable urban development and has got considerable attention in the global north, although relatively little is known in the global south. Therefore, the purpose of this study is to evaluate the accessibility of green spaces and the factors that enhance or inhibit their accessibility in urban centers of Ethiopia in reference to the emerging towns of Oromia's special zone surrounding Finfinne. This study used network analysis, backed by interviews and observation. Results show that the average green space per capita in the towns of Sululta, Sebeta, and Legetafo is 2.66 m2, 0.9 m2, and 2.17 m2, respectively. Findings also showed that 84.7%, 64.6%, and 60.4% of the inhabitants of Sululta, Sebeta, and Legetafo, respectively, have no access to green spaces from their residences within a walking distance of 300–1000 m. The key factors that hinder its accessibility are rapid urban expansion and population growth, violation of the plan, and institutional failure. The study suggests enhancing the percentage, coverage and per capita of green spaces, controlling land-use violations, and prioritizing it as one of the key government agendas in order to achieve the eleventh goal of the 2030 Sustainable Development Agenda.

Higher-Order Uniformly Convergent Numerical Scheme for Singularly Perturbed Differential Difference Equations with Mixed Small Shifts

Abstract: This paper deals with numerical treatment of singularly perturbed differential difference equations involving mixed small shifts on the reaction terms. The highest-order derivative term in the equation is multiplied by a small perturbation parameter taking arbitrary values in the interval . For small values of , the solution of the problem exhibits exponential boundary layer on the left or right side of the domain and the derivatives of the solution behave boundlessly large. The terms having the shifts are treated using Taylor’s series approximation. The resulting singularly perturbed boundary value problem is solved using exponentially fitted operator FDM. Uniform stability of the scheme is investigated and analysed using comparison principle and solution bound. The formulated scheme converges uniformly with linear order before Richardson extrapolation and quadratic order after Richardson extrapolation. The theoretical analysis of the scheme is validated using numerical test examples for different values of and mesh number .