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.

Optimal control strategies for the transmission risk of COVID-19.

Abstract: In this paper, we apply optimal control theory to a novel coronavirus (COVID-19) transmission model given by a system of non-linear ordinary differential equations. Optimal control strategies are obtained by minimizing the number of exposed and infected population considering the cost of implementation. The existence of optimal controls and characterization is established using Pontryagin's Maximum Principle. An expression for the basic reproduction number is derived in terms of control variables. Then the sensitivity of basic reproduction number with respect to model parameters is also analysed. Numerical simulation results demonstrated good agreement with our analytical results. Finally, the findings of this study shows that comprehensive impacts of prevention, intensive medical care and surface disinfection strategies outperform in reducing the disease epidemic with optimum implementation cost.

Fabrication of novel 1D/2D V2O5/g-C3N4 composites as Z-scheme photocatalysts for CR degradation and Cr (VI) reduction under sunlight irradiation

Abstract: Photocatalytic materials for environmental remediation of organic pollutants and heavy metals require not only a strong visible light response and high photocatalytic performance, but also the regeneration and reuse of catalysts. In this work, 1D/2D V2O5 nanorods/g-C3N4 nanosheets (VONRs/CNNs) composites were prepared by a facile impregnation method and employed in the degradation of a Congo red (CR) and reduction of Cr (VI) under sunlight irradiation. The as-prepared samples were studied by several characterization techniques including XRD, SEM, TEM, EDS, XPS, FTIR, UV–vis DRS and PL. Results revealed that the interface interaction between VONRs and CNNs was recognized via V2O5 nanorods loading on the surface of g-C3N4 nanosheets, improving the separation and transfer of photogenerated electron-hole pairs and restraining the recombination rate of charge carriers. As a result, the photocatalytic activity of the composites was enhanced in comparison with pure CNNs and VONRs. The photocatalytic efficiency of optimal composite (4-VONRs/CNNs) for the removal of CR (Cr (VI)) was about 9.33 (4.22) and 73.52 (19.2) times higher than that of pure CNNs and VONRs, respectively. Meanwhile, the 4-VONRs/CNNs exhibited good photocatalytic stability in recycling experiments. Such enormous enhancement in photocatalytic performance was predominantly ascribed to the efficient separation and transfer of photogenerated electron-hole pairs at the VONRs/CNNs interface imparted through the direct Z-scheme charge carrier migration mechanism. Moreover, the energy band structure and the quenching effects of different scavengers demonstrated that the electrons of CNNs and holes of VONRs with higher oxidizability and reducibility are the real participants in photocatalytic reactions.

Meat Consumption Culture in Ethiopia.

Abstract: The consumption of animal flesh food in Ethiopia has associated with cultural practices. Meat plays pivotal and vital parts in special occasions and its cultural symbolic weight is markedly greater than that accorded to most other food. Processing and cooking of poultry is a gender based duty and has socio-cultural roles. Ethiopians are dependent on limited types of animals for meats due to the taboo associated culturally. Moreover, the consumption of meat and meat products has a very tidy association with religious beliefs, and are influenced by religions. The main religions of Ethiopia have their own peculiar doctrines of setting the feeding habits and customs of their followers. They influence meat products consumption through dictating the source animals that should be used or not be used for food, and scheduling the days of the years in periodical permeation and restriction of consumptions which in turn influences the pattern of meat consumption in the country. In Ethiopia, a cow or an ox is commonly butchered for the sole purpose of selling within the community. In special occasions, people have a cultural ceremony of slaughtering cow or ox and sharing among the group, called Kircha, which is a very common option of the people in rural area where access of meat is challenging frequently.

Evaluation of seasonal and temporal variations of groundwater quality around Jawaharnagar municipal solid waste dumpsite of Hyderabad city, India

Abstract: The present study aimed to assess the impact of municipal solid waste dumpsite on groundwater bodies at Hyderabad, India. Leachate and groundwater samples collected through pre- and post-monsoon analyzed the physicochemical, microbiological, biological and heavy metals. The analytical data were compared with Bureau of Indian Standards (BIS) drinking water quality standards. Water quality index (WQI), heavy metal pollution indices like heavy metal evaluation index (HEI) and degree of contamination (Cd) are calculated for groundwater samples. High total dissolve solids values in leachates revealed that they were highly contaminated with organic and inorganic salts. Biological oxygen demand values indicated that dumpsite was “old and stabilized” with decreasing biodegradability from time to time. According to WQI, about 75% of the water samples identified as “Poor” category that is not suitable for neither drinking nor domestic purposes as per BIS standards. Similarly, HEI and Cd results indicated that majority of the samples are labeled with low-metal pollution status. Spatial patterns obtained through geographic information systems using inverse distance weighted interpolation technique revealed that the concentrations of various parameters are high due to increased degradation of solid wastes during rainfall, especially during the post-monsoon. The study suggested that leachates have treated prior to disposal on land, and continuous monitoring of groundwater wells is required to minimize the pollution and potential health hazards.