Harla Journal of Applied Science and Materials http://journals.ddu.edu.et/index.php/HJASM <p>The HJASM is a peer-reviewed an open access journal devoted primarily to the original research contributions containing original scientific findings in any of the science fields, having national and international appeal and significance. It follows a rigorous, objectively and constructively peer review process which publishes original scientific articles from across all areas of natural sciences (physical, biological, chemical, pharmaceutical, geological, sport science, computational sciences, and material science) covering both fundamental and applied aspect of science including interdisciplinary researches around the world. Its publications include original full length research articles, short communications, review articles, books and book reviews, letters to editor, comments on critiques of published materials, information related to conferences and any other related relevant topics. Submissions of Manuscripts from scientists working in academic institutions, industry, companies, in Ethiopia or elsewhere in the globe having national and international interest are accepted for publication.</p> en-US solomon.zerhun@ddu.edu.et (Solomon Zerhun (PhD)) tsega.endashaw@ddu.edu.et (Tsega Endashaw) Sun, 30 Jun 2024 00:00:00 -0800 OJS 3.2.1.2 http://blogs.law.harvard.edu/tech/rss 60 Fabrication of Waste Ceramic Reinforced Polymer for Electrical Insulation Application and Characterization of the Mechanical and Physical Properties http://journals.ddu.edu.et/index.php/HJASM/article/view/132 <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p>Composite materials continue to be the forefront materials for many manufacturing industries. Due to their superior mechanical and physical properties, composite materials play a significant role in modern manufacturing technology. However, the cost of composite materials is seen to be a major challenge. In this thesis, waste floor tile ceramic particles are used as a reinforcement, so that a problem related to cost can be solved and sees a new way to manage construction ceramic waste materials. The main goal of this research is to propose a new composite material with an optimal physical and mechanical response for a low-voltage pin-type insulator. The ceramic reinforcement is prepared by crushing waste tiles with a stone crusher machine and sieving the powder under an average particle size of Ø&lt;0.5,0.5&lt; Ø &lt;1, and 1&lt; Ø &lt;2mm diameter. Characterization of major and minor oxides- concentration in the ceramic powder is determined using a complete silicate analysis. Then the reinforcement ceramic is added to a general- purpose epoxy resin-1003 with 30%,35%, and 40% by weight. Experimental test samples are fabricated using a stir-casting technique. Taguchi L9 OA design of experiment is used for designing each experimental sample. Experimental analysis of physical properties such as water absorption and electrical resistance, specifically dielectric strength is investigated. Further mechanical responses such as flexural strength, and compressive strength are investigated. Finally, Minitab software is used to optimize process parameters. The research shows reinforcing 0.5&lt;Ø&lt;1 mm ceramic particles with 30%wt, exhibit an optimum flexural strength of 142.788 Mpa, compressive strength of 85.64Mpa, water absorption of 0.3% along with dielectric strength of 5.92Kv/mm. The research findings show a promising leap in the way waste ceramic tiles can be recycled and utilized for electrical insulation applications.</p> </div> </div> </div> Nathnael Samson Amanuel, Desalegn Wogaso Copyright (c) 2024 Harla Journals and Author(s) https://creativecommons.org/licenses/by-nc/4.0/ http://journals.ddu.edu.et/index.php/HJASM/article/view/132 Sat, 12 Apr 2025 00:00:00 -0800 The effect of Tb/Yb co-doping on the optical, morphology, and structural properties of YV0.5P0.5O4 http://journals.ddu.edu.et/index.php/HJASM/article/view/133 Molebatsi D, Mokoena M, A.U Yimamu, Motloung S.J, Tshabalala K.G Copyright (c) 2024 Harla Journals and Author(s) https://creativecommons.org/licenses/by-nc/4.0/ http://journals.ddu.edu.et/index.php/HJASM/article/view/133 Sun, 30 Jun 2024 00:00:00 -0800 Biodiversity Assessment of Mammals and Birds in Potential Oil Exploration Areas of Central Afar National Regional State http://journals.ddu.edu.et/index.php/HJASM/article/view/134 <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p>Energy is one of the key elements for economic development that could be derived from the diversity of modern energy sources like oil and other energy sources. Afar National Regional State is one of the areas in Ethiopia that have significant amount energy resources including the geothermal oil and natural gas that scattered in the Ethiopian Rift Valley of Afar Depression. Despite of this huge potential energy source more than 90% of the rural population still relies on traditional fuel wood. The fossil fuel exploration and development is expected to solve the existing problem. One of it is by implementing oil exploration. The exploration and production may have impact on the ecology of the environment. As Ethiopia is one of the top 25 biodiversity-rich countries in the world, and hosts two of the world’s 34 biodiversity hotspots, particular care is needed in development of such projects. Particularly, Rift Valley ecosystem includes more than 15 protected. Therefore, to reduce such ecological in particular to forecast the impact faunal survey is used to find solution and to take necessary mitigation action before its full operation. The field reconnaissance survey on the species composition of mammals and birds was conducted from August 23- 31, 2019. In the survey, different species of mammals, birds, reptiles and amphibians were recorded. In general, 30 species of small mammals belonging to 9 order and 20 families were recorded. All the recorded species had grouped under Least Concern of IUCN conservation status categories. In addition to these 129 species of birds belonging to 51 families were also recorded of which five were threatened. At least three species of reptiles and one species of amphibians were also recorded. Despite the area is considered as desert it relatively possesses high diversity of mammals and birds. The area also possesses different habitats, which is suitable for wild animals. Thus, during the oil exploration and production proper conservation and mitigation actions should be taken for the protection and conservation of the fauna and flora diversity of the area.</p> </div> </div> </div> Mohammed Kasso Copyright (c) 2024 Harla Journals and Author(s) https://creativecommons.org/licenses/by-nc/4.0/ http://journals.ddu.edu.et/index.php/HJASM/article/view/134 Sat, 12 Apr 2025 00:00:00 -0800 Prevalence of Early Breast Feeding Termination and Associated Factors among Mothers with Children Aged 2 to 3 Years in Dire Dawa City http://journals.ddu.edu.et/index.php/HJASM/article/view/136 <div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p><strong>Background</strong>: Breast milk is the primary natural food for children. It has nutritional, immunological, social and psychological benefits. Stopping breastfeeding before two years of age has several adverse concerns to children. Despite some studies have indicated practice and duration of breast feeding in the first one year, prevalence of mothers ending the recommended duration of breast feeding and associated factors has not been observed in Dire Dawa city. Thus, this study aimed to fill this stated gap.</p> <p><strong>Methods</strong>: Community based cross-sectional study was conducted among mothers of children aged 2 to 3 years in Dire Dawa city from June 04 to July 08 in 2022. Two-stage sampling technique was employed. Association between early breastfeeding cessation and explanatory variables were analyzed using logistic regression model and degree of association was quantified by AOR with 95% CI.</p> <p><strong>Results</strong>: The prevalence of early breastfeeding termination was 44.8 % at (95% CI: 42%-48%). Mothers with 3rd birth order (AOR = 0.472; 95%CI: 0.311 0.715), gave birth in private facility (AOR = 0.376; 95% CI: 0.236 0.598), attended higher education (AOR = 0.403; 95% CI: 0.205-0.792), aged above 35 years (AOR = 0.400 95% CI: 0.240-0.667), had good breastfeeding knowledge (AOR = 0.229; 95% CI: 0.108- 0.483), husbands who support breastfeeding (AOR = 0.202; 95% CI: 0.130-0.312), were less likely to cease breastfeeding early than counterparts. However, mothers being employed (AOR = 1.784; 95% CI: 1.160-2.743), unmarried or separated from husbands (AOR = 1.631; 95% CI: 1.058-2.515) were less likely to cease breastfeeding early than counterparts.</p> <p><strong>Conclusion</strong>: Education, age, occupation of women, breastfeeding knowledge, birth order, delivery place, marital status, husband support of breastfeeding were significantly predictors of early breastfeeding termination. Hence, promotion programs of continuing breastfeeding should be focused among younger age, uneducated, low education, employed, unmarried women to reduce early breastfeeding termination.</p> </div> </div> </div> Mengistu Abebe Tegenge, Ayitenew Agegn Gwadu Copyright (c) 2024 Harla Journals and Author(s) https://creativecommons.org/licenses/by-nc/4.0/ http://journals.ddu.edu.et/index.php/HJASM/article/view/136 Sat, 12 Apr 2025 00:00:00 -0800 Theoretical Modeling of Mass Transfer and High-Energy Emissions in X- Ray Binaries with Red Supergiants http://journals.ddu.edu.et/index.php/HJASM/article/view/137 Belay Sitotaw Goshu Copyright (c) 2024 Harla Journals and Author(s) https://creativecommons.org/licenses/by-nc/4.0/ http://journals.ddu.edu.et/index.php/HJASM/article/view/137 Sat, 12 Apr 2025 00:00:00 -0800