Ethiopian Journal of Science and Technology <p>The <em>Ethiopian Journal of Science and Technology</em> (EJST) publishes high quality original&nbsp;&nbsp; research articles, reviews, short communications, and feature articles on basic and applied aspects of science, technology, agriculture, health and other related fields.</p> <p>Other websites associated with this journal:&nbsp;<a title="" href="" target="_blank" rel="noopener"></a></p> en-US <p>The copyright belongs to the journal.</p><p>The articles in Ethiopian Journal of Science and Technology are Open Access distributed under the terms of the Creative Commons Attribution License (<a title="The articles in Ethiopian Journal of Science and Technology are Open Access distributed under the terms of the Creative Commons Attribution License ( BY4.0)." href="/index.php/ejst/manager/setup/The%20articles%20in%20Ethiopian%20Journal%20of%20Science%20and%20Technology%20are%20Open%20Access%20distributed%20under%20the%20terms%20of%20the%20Creative%20Commons%20Attribution%20License%20(http:/" target="_blank"></a>).</p> (Dr Melaku Wale) (Dr Tsegaye Kassa) Tue, 04 Aug 2020 00:00:00 +0000 OJS 60 Heat and mass transfer analysis in unsteady boundary layer flow of Maxwell nanofluid over a stretching sheet <p>This paper presents analytic study of heat and mass transfer in a two-dimensional, unsteady flow of Maxwell nanofluids over a horizontal stretching sheet. The non-linear governing equations with the relevant boundary conditions have been simplified by using similarity transformations and the resulting equations are solved by using the homotopy analysis method. The convergence and accuracy of the solutions are verified. Impacts of magnetic field, thermal radiation, heat source, surface permeability and chemical reaction on velocity, temperature and nanoparticles volume fraction profiles are examined and presented in graphical and tabular forms. The study reveals that increasing the effect of heat source maximizes the temperature profile whereas it reduces the nanoparticle volume fraction profile in the boundary layer. On the other hand, the increase in chemical reaction is found to enhance the nanoparticle concentration.</p> <p>Keywords:- Homotopy Analysis Method; Unsteady Flow; Boundary Layer Flow; Maxwell Nanofluid</p> Eshetu Haile, Bandari Shankar, Eleni Seid, Raja Shekar Copyright (c) Tue, 30 Jun 2020 00:00:00 +0000 Antibacterial activity of Acanthus sennii extracts against Staphylococcus aureus and Escherichia coli pathogens <p>Medicinal plants offer a major and accessible source of health care to people living in developing countries. Increasing drug resistant microbial infections intensified the search for new, safer, and more efficacious agents against microbial infections. <em>Acanthus sennii </em>is one of the medicinal plants used traditionally for the treatment of different infectious diseases in Ethiopia. Therefore, this study was carried out to evaluate antibacterial activity of <em>A. sennii </em>against pathogenic bacteria. Plant materials were extracted by maceration technique with chloroform, ethanol and water solvents. The antibacterial activities of the crude extracts of the plant were carried out by the agar well diffusion method. Broth dilution method was used to determine minimum inhibitory and streak plate bactericidal concentration of extracts. The results revealed that ethanol extracts of leaves revealed high antibacterial activity against standard strains of <em>Staphylococcus aureus </em>with inhibition zone of 14±0.6 mm at 25 mg/ml and 17±0.7 mm at 50 mg/ml. Ethanol extracts of buds showed high antibacterial activity against standard strains of <em>S. aureus </em>with inhibition zone of 25.7±0.7 mm at 100 mg/ml, also against standard strains of <em>E. coli </em>with inhibition zone of 16 mm at 50 mg/ml and 23.7 mm at 100 mg/ml. The mean minimum inhibitory concentration of 5.2±1.8 and 2.6±0.5 mg/ml was recorded for ethanol extract of leaves against standard strains of <em>E. coli </em>and clinical isolates of <em>S. aureus</em>; the mean minimum bactericidal concentration of 4.2±1.0 mg/ml with ethanol extract of leaves against standard strains of <em>S. aureus; </em>and the mean minimum bactericidal concentration of 12.5 mg/ml against standard strains and clinical isolates of <em>E. coli. </em>The result showed that<em> A. sennii </em>could be a candidate in the search for new antibacterial agents against these bacteria and its use in ethnomedicinal treatment of infectious diseases used by local communities may be validated. Isolating bio-active components and determining toxicity are future agenda.</p> <p><strong>Keywords</strong>: <em>Acanthus sennii, </em>Antibacterial activity, <em>E. coli</em>, Minimum inhibition concentration, Minimum bactericidal concentration, <em>S. aureus </em></p> <p>&nbsp;</p> Kindu Geta, Mulugeta Kibret Copyright (c) Tue, 30 Jun 2020 00:00:00 +0000 Solid waste management practice and dumpsite suitability analysis using GIS technology in Debre Markos town, Ethiopia <p>Solid waste management system is the most difficult task that many countries face. The aim of this study was to evaluate the effectiveness of solid waste management practices of households and analyze dumpsites' environmental suitability in Debre Markos town. Primary data were collected from randomly selected households using structured questionnaire and from secondary data from different bureaus, from research and other reports in 2017. Qualitative and quantitative techniques were used to evaluate solid waste management practices. Data were analyzed using statistical package for social Science and Geographical Information System computer program. The results revealed that households dominantly produced biodegradable solid wastes (87.6%) with the generation rate of 0.3 kg/person/day. This made the daily total solid waste generation of households up to 6210 kg (17 m<sup>3</sup>). The suitability map of the area for landfill showed that 1.4% of the study area was highly suitable, 36% was moderately suitable and 58% was less suitable. Moreover, 4.7% of the area was found unsuitable to be used for waste disposal. In conclusion, sustainable solid waste management systems must be executed, the structure and capacity of the municipality improved and integrated solid waste management practice must be applied for a healthy environment. Moreover, the municipality should make dumpsites environmentally sound and socially acceptable to decrease impacts of solid wastes on the communal land, on human, on animal and on environmental health.</p> <p><strong>Keywords: </strong>Dumpsite; Solid waste; Biodegradable; Suitability; Environmental health; Geographic Information system; Landfill; Incineration.</p> Anchinalu Birkie, Solomon Addisu, Asnake Mekuriaw Copyright (c) Prevalence and associated risk factors of intestinal parasitic infections among primary school children at Bure town, north-west Ethiopia <p>The burden of intestinal parasitic infections (IPIs) has been a common problem on children in Ethiopia. While communities in Bure town, northwest Ethiopia, are presumed to be exposed to IPIs, no study has been conducted before. The aim of this study was therefore to assess the prevalence of IPIs and associated risk factors among school children in Bure town by conducting a cross-sectional study from January to June 2019. A total of 430 students were selected using stratified systematic random sampling technique. Direct wet-mount and formal-ether concentration techniques were used for parasitological analysis from stool samples taken from each student. Information about the risk factors was collected using structured questionnaire. Data were analyzed using SPSS version 24. The overall prevalence of IPIs among the children involved in the study was found to be 40% (172/430). Some 37.7% of the students exhibited single parasite infection, 2.1% double and 0.23% triple parasite. Seven species of intestinal parasites were detected, and <em>Entamoeba histolytica/dispar</em> was the most prevalent parasite (22.1%) followed by <em>Giardia lamblia </em>(8.6%), hookworms (6.75%) and <em>Ascaris lumbricoides</em> (3.7%). <em>Hymenolepis nana, Trichuris trichuira </em>and<em> Taenia species </em>were rare &nbsp;(&lt;1% prevalence each). Knowledge about personal and food hygiene as well as environmental sanitation were the most important predictors for IPIs (<em>P</em>&lt;0.05). Primary school children in Bure town are at high risk of IPIs. Awareness creation on personal hygiene and environmental sanitation is strongly recommended.</p> <p><strong>Keywords:</strong> Intestinal parasitic infections; Prevalence; Primary school children; Risk factor; Bure town</p> Baye Sitotaw, Yezina Gebeyaw, Haile Mekonnen Copyright (c) Tue, 30 Jun 2020 00:00:00 +0000 Efficacy of the ethanol extracts of the leaves of some plant species on the mortality of maize weevils, Sitophilus zeamais (Curculionidae: Coleoptera) and prevention of grain damage <p><em>Sitophilus zeamais</em> (maize weevil) damages maize, a major cereal crop in Ethiopia. A study was conducted to determine the anti-weevil activities of ethanol extracts of leaves of <em>Juniperus procera, Phytolacca dodecandra, Ostegia integrifolia, Sansevieria trifasciata, </em>and<em> Eucalyptus globulus</em>. Extraction was done using 70% ethanol. Two types of tests (toxicity and efficacy) were conducted using three doses, i.e., 50, 75, and 100 ml/kg of each plant. In the toxicity test, weevil mortality was measured at the 6<sup>th</sup>, 12<sup>th</sup>, 24<sup>th</sup>, 48<sup>th</sup>, and 72<sup>nd</sup> hours, then weekly for five weeks. For efficacy test, weevil mortality and grain damage (weight loss, percent holes, and percent germination) were assessed three months after treatment. <em>J. procera </em>and <em>P. dodecandra </em>were more toxic (96.6% and 96.4% mortality rate, respectively). The 50 and 75 ml/kg doses of <em>E. globulus, </em>75 and 100 ml/kg doses of <em>J. procera, </em>of <em>P. dodecandra, </em>and of <em>S. trifasciata</em> killed 100% of the weevils; in the control mortality was 23.3%. Grain weight loss was high in the control (7.8%) followed by grains treated by 75 ml/kg extracts of <em>O. integrifolia </em>(5.9%). Percentage holes was high in the control (70%) followed by 75 ml/kg extracts of <em>O. integrifolia </em>(26.7%). Germination was high in grains treated with 50 and 75 ml/kg doses of <em>J. procera, E. globulus, S. trifasciata, </em>and<em> P. dodecandra </em>in descending order. The 75 and 100 ml/kg extracts of <em>J. procera, E. globulus, S. trifasciata, </em>and<em> P. dodecandra </em>were good candidates in the control of maize weevils with limitations of allelopathy in the 100 ml/kg.</p> <p><strong>Keywords:</strong> <em>Juniperus procera;</em> M<em>aize weevil</em><em>; </em><em>Ostegia integrifolia; Phytolacca dodecandra; Sansevieria trifasciata; Sitophilus zeamais</em>.</p> Mastewal Alehegn, Destaw Damtie, Melaku Wale, Yewulsew Kebede Copyright (c)