Search results for: Tesfay Gidey
35 Prioritizing Forest Conservation Strategies Using a Multi-Attribute Decision Model to Address Concerns with the Survival of the Endangered Dragon Tree (Dracaena ombet Kotschy and Peyr.)
Authors: Tesfay Gidey, Emiru Birhane, Ashenafi Manaye, Hailemariam Kassa, Tesfay Atsbha, Negasi Solomon, Hadgu Hishe, Aklilu Negussie, Petr Madera, Jose G. Borges
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The globally endangered Dracaena ombet is one of the ten dragon multipurpose tree species in arid ecosystems. Anthropogenic and natural factors are now impacting the sustainability of the species. This study was conducted to prioritize criteria and alternative strategies for the conservation of the species using the analytical hierarchy process (AHP) model by involving all relevant stakeholders in the Desa'a dry Afromontane forest in northern Ethiopia. Information about the potential alternative strategies and the criteria for their evaluation was first collected from experts, personal experiences, and literature reviews. Afterward, they were validated using stakeholders' focus group discussions. Five candidate strategies with three evaluation criteria were considered for prioritization using the AHP techniques. The overall priority ranking value of the stakeholders showed that the ecological criterion was deemed as the most essential factor for the choice of alternative strategies, followed by the economic and social criteria. The minimum cut-off strategy, combining exclosures with the collection of only 5% of plant parts from the species, soil and water conservation, and silviculture interventions, was selected as the best alternative strategy for sustainable D. ombet conservation. The livelihood losses due to the selected strategy should be compensated by the collection of non-timber forest products, poultry farming, home gardens, rearing small ruminants, beekeeping, and agroforestry. This approach may be extended to study other dragon tree species and explore strategies for the conservation of other arid ecosystems.Keywords: conservation strategies, analytical hierarchy process model, Desa'a forest, endangered species, Ethiopia, overexploitation
Procedia PDF Downloads 9234 Using the Yield-SAFE Model to Assess the Impacts of Climate Change on Yield of Coffee (Coffea arabica L.) Under Agroforestry and Monoculture Systems
Authors: Tesfay Gidey Bezabeh, Tânia Sofia Oliveira, Josep Crous-Duran, João H. N. Palma
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Ethiopia's economy depends strongly on Coffea arabica production. Coffee, like many other crops, is sensitive to climate change. An urgent development and application of strategies against the negative impacts of climate change on coffee production is important. Agroforestry-based system is one of the strategies that may ensure sustainable coffee production amidst the likelihood of future impacts of climate change. This system involves the combination of trees in buffer extremes, thereby modifying microclimate conditions. This paper assessed coffee production under 1) coffee monoculture and 2) coffee grown using an agroforestry system, under a) current climate and b) two different future climate change scenarios. The study focused on two representative coffee-growing regions of Ethiopia under different soil, climate, and elevation conditions. A process-based growth model (Yield-SAFE) was used to simulate coffee production for a time horizon of 40 years. Climate change scenarios considered were representative concentration pathways (RCP) 4.5 and 8.5. The results revealed that in monoculture systems, the current coffee yields are between 1200-1250 kg ha⁻¹ yr⁻¹, with an expected decrease between 4-38% and 20-60% in scenarios RCP 4.5 and 8.5, respectively. However, in agroforestry systems, the current yields are between 1600-2200 kg ha⁻¹ yr⁻¹; the decrease was lower, ranging between 4-13% and 16-25% in RCP 4.5 and 8.5 scenarios, respectively. From the results, it can be concluded that coffee production under agroforestry systems has a higher level of resilience when facing future climate change and reinforces the idea of using this type of management in the near future for adapting climate change's negative impacts on coffee production.Keywords: Albizia gummifera, CORDEX, Ethiopia, HADCM3 model, process-based model
Procedia PDF Downloads 11833 Impact of Land-Use and Climate Change on the Population Structure and Distribution Range of the Rare and Endangered Dracaena ombet and Dobera glabra in Northern Ethiopia
Authors: Emiru Birhane, Tesfay Gidey, Haftu Abrha, Abrha Brhan, Amanuel Zenebe, Girmay Gebresamuel, Florent Noulèkoun
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Dracaena ombet and Dobera glabra are two of the most rare and endangered tree species in dryland areas. Unfortunately, their sustainability is being compromised by different anthropogenic and natural factors. However, the impacts of ongoing land use and climate change on the population structure and distribution of the species are less explored. This study was carried out in the grazing lands and hillside areas of the Desa'a dry Afromontane forest, northern Ethiopia, to characterize the population structure of the species and predict the impact of climate change on their potential distributions. In each land-use type, abundance, diameter at breast height, and height of the trees were collected using 70 sampling plots distributed over seven transects spaced one km apart. The geographic coordinates of each individual tree were also recorded. The results showed that the species populations were characterized by low abundance and unstable population structure. The latter was evinced by a lack of seedlings and mature trees. The study also revealed that the total abundance and dendrometric traits of the trees were significantly different between the two land uses. The hillside areas had a denser abundance of bigger and taller trees than the grazing lands. Climate change predictions using the MaxEnt model highlighted that future temperature increases coupled with reduced precipitation would lead to significant reductions in the suitable habitats of the species in northern Ethiopia. The species' suitable habitats were predicted to decline by 48–83% for D. ombet and 35–87% for D. glabra. Hence, to sustain the species populations, different strategies should be adopted, namely the introduction of alternative livelihoods (e.g., gathering NTFP) to reduce the overexploitation of the species for subsistence income and the protection of the current habitats that will remain suitable in the future using community-based exclosures. Additionally, the preservation of the species' seeds in gene banks is crucial to ensure their long-term conservation.Keywords: grazing lands, hillside areas, land-use change, MaxEnt, range limitation, rare and endangered tree species
Procedia PDF Downloads 9632 Quantifying and Prioritizing Agricultural Residue Biomass Energy Potential in Ethiopia
Authors: Angesom Gebrezgabiher Tesfay, Afafaw Hailesilasie Tesfay, Muyiwa Samuel Adaramola
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The energy demand boost in Ethiopia urges sustainable fuel options while it is mainly supplemented by traditional biomass and imported conventional fuels. To satisfy the deficiency it has to be sourced from all renewables. Thus identifying resources and estimating potential is vital to the sector. This study aims at an in-depth assessment to quantify, prioritize, and analyze agricultural residue biomass energy and related characteristic forms. Biomass use management and modernization seeks successive information and a clue about the resource quantity and characteristic. Five years of crop yield data for thirteen crops were collected. Conversion factors for their 20 residues are surveyed from the literature. Then residues amount potentially available for energy and their energy is estimated regional, crop-wise, residue-wise, and shares compared. Their potential value for energy is analyzed from two perspectives and prioritized. The gross potential is estimated to be 495PJ, equivalent to 12/17 million tons of oil/coal. At 30% collection efficiency, it is the same as conventional fuel import in 2018. Maize and sorghum potential and spatial availability are preeminent. Cotton and maize presented the highest potential values for energy from application and resource perspectives. Oromia and Amhara regions' contributions are the highest. The resource collection and application trends are required for future management that implicates a prospective study.Keywords: crop residue, biomass potential, biomass resource, Ethiopian energy
Procedia PDF Downloads 12331 A DEA Model in a Multi-Objective Optimization with Fuzzy Environment
Authors: Michael Gidey Gebru
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Most DEA models operate in a static environment with input and output parameters that are chosen by deterministic data. However, due to ambiguity brought on shifting market conditions, input and output data are not always precisely gathered in real-world scenarios. Fuzzy numbers can be used to address this kind of ambiguity in input and output data. Therefore, this work aims to expand crisp DEA into DEA with fuzzy environment. In this study, the input and output data are regarded as fuzzy triangular numbers. Then, the DEA model with fuzzy environment is solved using a multi-objective method to gauge the Decision Making Units’ efficiency. Finally, the developed DEA model is illustrated with an application on real data 50 educational institutions.Keywords: efficiency, DEA, fuzzy, decision making units, higher education institutions
Procedia PDF Downloads 5030 Cloning and Characterization of UDP-Glucose Pyrophosphorylases from Lactobacillus kefiranofaciens and Rhodococcus wratislaviensis
Authors: Mesfin Angaw Tesfay
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Uridine-5’-diphosphate (UDP)-glucose is one of the most versatile building blocks within the metabolism of prokaryotes and eukaryotes, serving as an activated sugar donor during the glycosylation of natural products. It is formed by the enzyme UDP-glucose pyrophosphorylase (UGPase) using uridine-5′-triphosphate (UTP) and α-d-glucose 1-phosphate as a substrate. Herein, two UGPase genes from Lactobacillus kefiranofaciens ZW3 (LkUGPase) and Rhodococcus wratislaviensis IFP 2016 (RwUGPase) were identified through genome mining approaches. The LkUGPase and RwUGPase have 299 and 306 amino acids, respectively. Both UGPase has the conserved UTP binding site (G-X-G-T-R-X-L-P) and the glucose -1-phosphate binding site (V-E-K-P). The LkUGPase and RwUGPase were cloned in E. coli, and SDS-PAGE analysis showed the expression of both enzymes forming about 36 KDa of protein band after induction. LkUGPase and RwUGPase have an activity of 1549.95 and 671.53 U/mg, respectively. Currently, their kinetic properties are under investigation.Keywords: UGPase, LkUGPase, RwUGPase, UDP-glucose, glycosylation
Procedia PDF Downloads 2329 A Data Envelopment Analysis Model in a Multi-Objective Optimization with Fuzzy Environment
Authors: Michael Gidey Gebru
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Most of Data Envelopment Analysis models operate in a static environment with input and output parameters that are chosen by deterministic data. However, due to ambiguity brought on shifting market conditions, input and output data are not always precisely gathered in real-world scenarios. Fuzzy numbers can be used to address this kind of ambiguity in input and output data. Therefore, this work aims to expand crisp Data Envelopment Analysis into Data Envelopment Analysis with fuzzy environment. In this study, the input and output data are regarded as fuzzy triangular numbers. Then, the Data Envelopment Analysis model with fuzzy environment is solved using a multi-objective method to gauge the Decision Making Units' efficiency. Finally, the developed Data Envelopment Analysis model is illustrated with an application on real data 50 educational institutions.Keywords: efficiency, Data Envelopment Analysis, fuzzy, higher education, input, output
Procedia PDF Downloads 5628 Terrain Classification for Ground Robots Based on Acoustic Features
Authors: Bernd Kiefer, Abraham Gebru Tesfay, Dietrich Klakow
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The motivation of our work is to detect different terrain types traversed by a robot based on acoustic data from the robot-terrain interaction. Different acoustic features and classifiers were investigated, such as Mel-frequency cepstral coefficient and Gamma-tone frequency cepstral coefficient for the feature extraction, and Gaussian mixture model and Feed forward neural network for the classification. We analyze the system’s performance by comparing our proposed techniques with some other features surveyed from distinct related works. We achieve precision and recall values between 87% and 100% per class, and an average accuracy at 95.2%. We also study the effect of varying audio chunk size in the application phase of the models and find only a mild impact on performance.Keywords: acoustic features, autonomous robots, feature extraction, terrain classification
Procedia PDF Downloads 36627 Cloning and Characterization of Uridine-5’-Diphosphate -Glucose Pyrophosphorylases from Lactobacillus Kefiranofaciens and Rhodococcus Wratislaviensis
Authors: Mesfin Angaw Tesfay
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Uridine-5’-diphosphate (UDP)-glucose is one of the most versatile building blocks within the metabolism of prokaryotes and eukaryotes serving as an activated sugar donor during the glycosylation of natural products. It is formed by the enzyme UDP-glucose pyrophosphorylase (UGPase) using uridine-5′-triphosphate (UTP) and α-d-glucose 1-phosphate as a substrate. Herein two UGPase genes from Lactobacillus kefiranofaciens ZW3 (LkUGPase) and Rhodococcus wratislaviensis IFP 2016 (RwUGPase) were identified through genome mining approaches. The LkUGPase and RwUGPase have 299 and 306 amino acids, respectively. Both UGPase has the conserved UTP binding site (G-X-G-T-R-X-L-P) and the glucose -1-phosphate binding site (V-E-K-P). The LkUGPase and RwUGPase were cloned in E. coli and SDS-PAGE analysis showed the expression of both enzymes forming about 36 KDa of protein band after induction. LkUGPase and RwUGPase have an activity of 1549.95 and 671.53 U/mg respectively. Currently, their kinetic properties are under investigation.Keywords: UGPase, LkUGPase, RwUGPase, UDP-glucose, Glycosylation
Procedia PDF Downloads 1926 Analyze and Visualize Eye-Tracking Data
Authors: Aymen Sekhri, Emmanuel Kwabena Frimpong, Bolaji Mubarak Ayeyemi, Aleksi Hirvonen, Matias Hirvonen, Tedros Tesfay Andemichael
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Fixation identification, which involves isolating and identifying fixations and saccades in eye-tracking protocols, is an important aspect of eye-movement data processing that can have a big impact on higher-level analyses. However, fixation identification techniques are frequently discussed informally and rarely compared in any meaningful way. With two state-of-the-art algorithms, we will implement fixation detection and analysis in this work. The velocity threshold fixation algorithm is the first algorithm, and it identifies fixation based on a threshold value. For eye movement detection, the second approach is U'n' Eye, a deep neural network algorithm. The goal of this project is to analyze and visualize eye-tracking data from an eye gaze dataset that has been provided. The data was collected in a scenario in which individuals were shown photos and asked whether or not they recognized them. The results of the two-fixation detection approach are contrasted and visualized in this paper.Keywords: human-computer interaction, eye-tracking, CNN, fixations, saccades
Procedia PDF Downloads 13325 Coexistence of Superconductivity and Spin Density Wave in Ferropnictide Ba₁₋ₓKₓFe₂As₂
Authors: Tadesse Desta Gidey, Gebregziabher Kahsay, Pooran Singh
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This work focuses on the theoretical investigation of the coexistence of superconductivity and Spin Density Wave (SDW)in Ferropnictide Ba₁₋ₓKₓFe₂As₂. By developing a model Hamiltonian for the system and by using quantum field theory Green’s function formalism, we have obtained mathematical expressions for superconducting transition temperature TC), spin density wave transition temperature (Tsdw), superconductivity order parameter (Sc), and spin density wave order parameter (sdw). By employing the experimental and theoretical values of the parameters in the obtained expressions, phase diagrams of superconducting transition temperature (TC) versus superconducting order parameter (Sc) and spin density wave transition temperature (Tsdw), versus spin density wave order parameter (sdw) have been plotted. By combining the two phase diagrams, we have demonstrated the possible coexistence of superconductivity and spin density wave (SDW) in ferropnictide Ba1−xKxFe2As2.Keywords: Superconductivity, Spin density wave, Coexistence, Green function, Pnictides, Ba₁₋ₓKₓFe₂As₂
Procedia PDF Downloads 17224 Concurrent Engineering Challenges and Resolution Mechanisms from Quality Perspectives
Authors: Grmanesh Gidey Kahsay
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In modern technical engineering applications, quality is defined in two ways. The first one is that quality is the parameter that measures a product or service’s characteristics to meet and satisfy the pre-stated or fundamental needs (reliability, durability, serviceability). The second one is the quality of a product or service free of any defect or deficiencies. The American Society for Quality (ASQ) describes quality as a pursuit of optimal solutions to confirm successes and fulfillment to be accountable for the product or service's requirements and expectations. This article focuses on quality engineering tools in modern industrial applications. Quality engineering is a field of engineering that deals with the principles, techniques, models, and applications of the product or service to guarantee quality. Including the entire activities to analyze the product’s design and development, quality engineering emphasizes how to make sure that products and services are designed and developed to meet consumers’ requirements. This episode acquaints with quality tools such as quality systems, auditing, product design, and process control. The finding presents thoughts that aim to improve quality engineering proficiency and effectiveness by introducing essential quality techniques and tools in some selected industries.Keywords: essential quality tools, quality systems and models, quality management systems, and quality assurance
Procedia PDF Downloads 15023 Heat and Mass Transfer in MHD Flow of Nanofluids through a Porous Media Due to a Permeable Stretching Sheet with Viscous Dissipation and Chemical Reaction Effects
Authors: Yohannes Yirga, Daniel Tesfay
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The convective heat and mass transfer in nanofluid flow through a porous media due to a permeable stretching sheet with magnetic field, viscous dissipation, and chemical reaction and Soret effects are numerically investigated. Two types of nanofluids, namely Cu-water and Ag-water were studied. The governing boundary layer equations are formulated and reduced to a set of ordinary differential equations using similarity transformations and then solved numerically using the Keller box method. Numerical results are obtained for the skin friction coefficient, Nusselt number and Sherwood number as well as for the velocity, temperature and concentration profiles for selected values of the governing parameters. Excellent validation of the present numerical results has been achieved with the earlier linearly stretching sheet problems in the literature.Keywords: heat and mass transfer, magnetohydrodynamics, nanofluid, fluid dynamics
Procedia PDF Downloads 29022 Medicinal and Edible Plants in the Highlands of Tigray, Ethiopia
Authors: Masho Mebrahtom Gebrehiwot, Gidey Yirga
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Tigray highlands in northern Ethiopia, is characterized by a wide range of ecological conditions and climate. The siege of Tigray is believed to cause the deaths of nearly 600,000 civilians mainly due to starvation and lack of medicine. In this study, the most important edible and medicinal plants used during the siege of Tigray were investigated. Semi-structured interviews, observation and guided field walks were used in 500 informants (300 males and 200 females) selected randomly from two districts. A total of 25 species of medicinal plants were collected and identified for treating 30 human ailments. Furthermore, a total of 21 edible plants were also collected and identified. Nearly 68.75% of these species were wild and harvested mainly for their leaves and the remedies were administered through dermal, nasal and oral routes. Oral and dermal applications were the highest and most used route of application. Famen foods significantly saved thousands of human lives during the siege of Tigray both in urban and rural communities. We suggest domestication of some of the wild medicinal plants for long term conservation of the species. Documentation of farmers’ knowledge, attitude and practices of ethnobotany would be very important before the indigenous knowledge is lost forever.Keywords: ethnobotany, tigray, siege, application
Procedia PDF Downloads 1221 Public Transport Assignment at Adama City
Authors: Selamawit Mulubrhan Gidey
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Adama city, having an area of 29.86 km2, is one of the main cities in Ethiopia experiencing rapid growth in business and construction activities which in turn with an increasing number of vehicles at an alarming rate. For this reason, currently, there is an attempt to develop public transport assignment modeling in the city. Still, there is a huge gap in developing public transport assignments along the road segments of the city with operational and safety performance due to high traffic volume. Thus, the introduction of public transport assignment modeling in Adama City can have a massive impact on the road safety and capacity problem in the city. City transport modeling is important in city transportation planning, particularly in overcoming existing transportation problems such as traffic congestion. In this study, the Adama City transportation model was developed using the PTV VISUM software, whose transportation modeling is based on the four-step model of transportation. Based on the traffic volume data fed and simulated, the result of the study shows that the developed model has better reliability in representing the traffic congestion conditions in Adama city, and the simulation clearly indicates the level of congestion of each route selected and thus, the city road administrative office can take managerial decisions on public transport assignment so as to overcome traffic congestion executed along the selected routes.Keywords: trip modelling, PTV VISUM, public transport assignment, congestion
Procedia PDF Downloads 4320 Biosynthesis of L-Xylose from Xylitol Using a Dual Enzyme Cascade in Escherichia coli
Authors: Mesfin Angaw Tesfay
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L-xylose is an important intermediate in the pharmaceutical industry, playing a key role in the production of various antiviral and anticancer drugs. Despite its significance, L-xylose is a rare and costly sugar with limited availability in nature. In recent years, enzymatic production methods have garnered considerable attention due to their benefits over conventional chemical synthesis. In this research, a dual enzyme cascade system was developed to synthesize L-xylose from an inexpensive substrate, xylitol. The study involved cloning and co-expressing two key genes: the L-fucose isomerase (L-fucI) gene from Escherichia coli K-12 and the xylitol-4-dehydrogenase (xdh) gene from Pantoea ananatis ATCC 43072 in Escherichia coli. The resulting recombinant cells, engineered with the PET28a-xdh/L-fucI vector, were able to effectively convert xylitol to L-xylose. The system showed optimal performance at 40°C and a pH of 10.0. Moreover, Zn²⁺ (7.5 mM) enhanced the catalytic activity by 1.34 times. This approach yielded 52.2 g/L of L-xylose from an initial 80 g/L xylitol concentration, with a 65% conversion efficiency and a productivity rate of 1.86. The study highlights a practical method for producing L-xylose from xylitol through a co-expression system carrying the L-fucI and xdh genes.Keywords: l-fucose isomerase, xylitol-4-dehydrogenase, l-xylose, xylitol, co-expression
Procedia PDF Downloads 2419 Human Immunodeficiency Virus (HIV) Test Predictive Modeling and Identify Determinants of HIV Testing for People with Age above Fourteen Years in Ethiopia Using Data Mining Techniques: EDHS 2011
Authors: S. Abera, T. Gidey, W. Terefe
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Introduction: Testing for HIV is the key entry point to HIV prevention, treatment, and care and support services. Hence, predictive data mining techniques can greatly benefit to analyze and discover new patterns from huge datasets like that of EDHS 2011 data. Objectives: The objective of this study is to build a predictive modeling for HIV testing and identify determinants of HIV testing for adults with age above fourteen years using data mining techniques. Methods: Cross-Industry Standard Process for Data Mining (CRISP-DM) was used to predict the model for HIV testing and explore association rules between HIV testing and the selected attributes among adult Ethiopians. Decision tree, Naïve-Bayes, logistic regression and artificial neural networks of data mining techniques were used to build the predictive models. Results: The target dataset contained 30,625 study participants; of which 16, 515 (53.9%) were women. Nearly two-fifth; 17,719 (58%), have never been tested for HIV while the rest 12,906 (42%) had been tested. Ethiopians with higher wealth index, higher educational level, belonging 20 to 29 years old, having no stigmatizing attitude towards HIV positive person, urban residents, having HIV related knowledge, information about family planning on mass media and knowing a place where to get testing for HIV showed an increased patterns with respect to HIV testing. Conclusion and Recommendation: Public health interventions should consider the identified determinants to promote people to get testing for HIV.Keywords: data mining, HIV, testing, ethiopia
Procedia PDF Downloads 49518 Negotiated Peace in Africa: A Case Study on the Pretoria Peace Deal between Federal Democratic Republic of Ethiopia and Tigray Peoples Liberation Front
Authors: Daniel Gidey, Kunwar Siddarth Dadhwal, Tagel Wondimu
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There are numerous ways for ending conflict; hitherto, most conflicts are resolved either through negotiated or victor's peace, this article is about the former. Negotiations entail concessions, consensus-building, and mutual trust in order to transform a belligerent situation into a settlement. In such a context, regional and sub-regional organizations play a critical role in mediating conflicting parties so as to prevent, manage, and resolve conflicts between and among conflicting parties. This article is about the AU-led negotiated peace deal on the bloody conflict between the Tigray Peoples Liberation Front (TPLF) and the Federal Democratic Republic of Ethiopia (FDRE) by undertaking the Pretoria Peace Accord as a case study. In terms of research method, the article is based on a critical evaluation of the literature and content analysis on the very research topic. Findings of the study revealed that the AU, through Olusegun Obasanjo and other dignitaries, played a critical role in nurturing compromise and mutual trust between the TPLF and the Ethiopian federal government so as to take along the Pretoria peace deal. Through critical literature review and content analysis of the Peace deal, the article has concluded that negotiated peace is likely, at least, to achieve negative peace.Keywords: regional organizations, peace promotion, African Union, negotiating conflicts, Northern Ethiopia, conflict resolution
Procedia PDF Downloads 7817 Potential Antibacterial Applications and Synthesis, Structural, Magnetic, Optical, and Dielectric Characterization of Nickel-Substituted Cobalt Ferrite Nanoparticles
Authors: Tesfay Gebremichael Reda
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Nanoparticle technology is fast progressing and is being employed in innumerable medical applications. At this time, the public's health is seriously threatened by the rise of bacterial strains resistant to several medications. Metal nanoparticles are a potential alternate approach for tackling this global concern, and this is the main focus of this study. The citrate precursor sol-gel synthesis method was used to synthesize the, Niₓ Co(₁-ₓ) Fe₂ O₄, (where x = 0.0:0.2:1.0) nanoparticle. XRD identified the development of the cubic crystal structure to have a preferential orientation along (311), and the average particle size was found to be 29-38 nm. The average crystallizes assessed with ImageJ software and origin 22 of the SEM are nearly identical to the XRD results. In the created NCF NPs, the FT-IR spectroscopy reveals structural examinations and the redistribution of cations between octahedral (505-428 cm-1) and tetrahedral (653-603 cm-1) locales. Finally, the decrease of coercive fields HC, 2384 Oe to 241.93 Oe replacement of Co²+ cation with Ni²+. Band gap energy rises as Ni concentration increases, which may be attributed to the fact that the ionic radii of Ni²+ ions are smaller than that of Co²+ ions, which results in a strong electrostatic interaction. On the contrary, except at x = 0.4, the dielectric constant decreases as the nickel concentration increases. According to the findings of this research work, nanoparticles composed of Ni₀.₄ Co₀.₄ Fe₂ O₄ have demonstrated a promising value against S. aureus and E. coli, and it suggests a proposed model for their potential use as a new source of antibacterial agents.Keywords: antimicrobial, band gap, citrate precursor, dielectric, nanoparticle
Procedia PDF Downloads 2616 Sustainable Production of Tin Oxide Nanoparticles: Exploring Synthesis Techniques, Formation Mechanisms, and Versatile Applications
Authors: Yemane Tadesse Gebreslassie, Henok Gidey Gebretnsae
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Nanotechnology has emerged as a highly promising field of research with wide-ranging applications across various scientific disciplines. In recent years, tin oxide has garnered significant attention due to its intriguing properties, particularly when synthesized in the nanoscale range. While numerous physical and chemical methods exist for producing tin oxide nanoparticles, these approaches tend to be costly, energy-intensive, and involve the use of toxic chemicals. Given the growing concerns regarding human health and environmental impact, there has been a shift towards developing cost-effective and environmentally friendly processes for tin oxide nanoparticle synthesis. Green synthesis methods utilizing biological entities such as plant extracts, bacteria, and natural biomolecules have shown promise in successfully producing tin oxide nanoparticles. However, scaling up the production to an industrial level using green synthesis approaches remains challenging due to the complexity of biological substrates, which hinders the elucidation of reaction mechanisms and formation processes. Thus, this review aims to provide an overview of the various sources of biological entities and methodologies employed in the green synthesis of tin oxide nanoparticles, as well as their impact on nanoparticle properties. Furthermore, this research delves into the strides made in comprehending the mechanisms behind the formation of nanoparticles as documented in existing literature. It also sheds light on the array of analytical techniques employed to investigate and elucidate the characteristics of these minuscule particles.Keywords: nanotechnology, tin oxide, green synthesis, formation mechanisms
Procedia PDF Downloads 5115 Understanding Regional Circulations That Modulate Heavy Precipitations in the Kulfo Watershed
Authors: Tesfay Mekonnen Weldegerima
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Analysis of precipitation time series is a fundamental undertaking in meteorology and hydrology. The extreme precipitation scenario of the Kulfo River watershed is studied using wavelet analysis and atmospheric transport, a lagrangian trajectory model. Daily rainfall data for the 1991-2020 study periods are collected from the office of the Ethiopian Meteorology Institute. Meteorological fields on a three-dimensional grid at 0.5o x 0.5o spatial resolution and daily temporal resolution are also obtained from the Global Data Assimilation System (GDAS). Wavelet analysis of the daily precipitation processed with the lag-1 coefficient reveals some high power recurred once every 38 to 60 days with greater than 95% confidence for red noise. The analysis also identified inter-annual periodicity in the periods 2002 - 2005 and 2017 - 2019. Back trajectory analysis for 3-day periods up to May 19/2011, indicates the Indian Ocean source; trajectories crossed the eastern African escarpment to arrive at the Kulfo watershed. Atmospheric flows associated with the Western Indian monsoon redirected by the low-level Somali winds and Arabian ridge are responsible for the moisture supply. The time-localization of the wavelet power spectrum yields valuable hydrological information, and the back trajectory approaches provide useful characterization of air mass source.Keywords: extreme precipitation events, power spectrum, back trajectory, kulfo watershed
Procedia PDF Downloads 6914 Synthesis, Structural, Magnetic, Optical, and Dielectric Characterization of Nickel-Substituted Cobalt Ferrite Nanoparticles and Potential Antibacterial Applications
Authors: Tesfay Gebremicheal Reda, K. Samatha, Paul Douglas Sanasi, D. Parajuli
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Nanoparticle technology is fast progressing and is being employed in innumerable medical applications. At this time, the public's health is seriously threatened by the rise of bacterial strains resistant to several medications. Metal nanoparticles are a potential alternate approach for tackling this global concern, and this is the main focus of this study. The citrate precursor sol-gel synthesis method was used to synthesize the Niₓ Co₁₋ₓ Fe₂ O₄, (where x = 0.0:0.2:1.0) nanoparticle. XRD identified the development of the cubic crystal structure to have a preferential orientation along (311), and the average particle size was found to be 29-38 nm. The average crystallizes assessed with ImageJ software and origin 22 of the SEM are nearly identical to the XRD results. In the created NCF NPs, the FT-IR spectroscopy reveals structural examinations and the redistribution of cations between octahedral (505-428 cm⁻¹) and tetrahedral (653-603 cm⁻¹) locales. As the Co²⁺ cation is substituted with Ni²⁺, the coercive fields HC decrease from 2384 Oe to 241.93 Oe. Band gap energy rises as Ni concentration increases, which may be attributed to the fact that the ionic radii of Ni²⁺ ions are smaller than that of Co²⁺ ions, which results in a strong electrostatic interaction. On the contrary, except at x = 0.4, the dielectric constant decreases as the nickel concentration increases. According to the findings of this research work, nanoparticles are composed of Ni₀.₄ Co₀.₆ Fe₂ O₄ have demonstrated a promising value against S. aureus and E. coli, and it suggests a proposed model for their potential use as a source of antibacterial agent.Keywords: antimicrobial, band gap, citrate precursor, dielectric, nanoparticle
Procedia PDF Downloads 7113 Students' Perspectives on Quality of Course Evaluation Practices and Feedbacks in Eritrea
Authors: Ermias Melake Tesfay
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The importance of evaluation practice and feedback to student advancement and retention has gained importance in the literature over the past ten years. So many issues and cases have been raised about the quality and types of evaluation carried out in higher education and the quality and quantity of student feedback. The aim of this study was to explore the students’ perspectives on the quality of course evaluation practice and feedback in College of Education and College of Science. The study used both quantitative and qualitative methods to collect data. Data were collected from third-year and fourth-year students of 13 departments in the College of Education and College of Science in Eritrea. A modified Service Performance (SERVPERF) questionnaire and focus group discussions were used to collect the data. The sample population comprised of 135 third-year and fourth-year students’ from both Colleges. A questionnaire using a 5 point Likert-scale was administered to all respondents whilst two focus group discussions were conducted. Findings from survey data and focus group discussions showed that the majority of students hold a positive perception of the quality of course evaluation practice but had a negative perception of methods of awarding grades and administrators’ role in listening to the students complain about the course. Furthermore, the analysis from the questionnaire showed that there is no statistically significant difference between third-year and fourth-year students, College of Education and College of Science and male and female students on the quality of course evaluation practice and feedback. The study recommends that colleges improve the quality of fairness and feedback during course assessment.Keywords: evaluation, feedback, quality, students' perception
Procedia PDF Downloads 15612 The Role of Privatization on the Formulation of Productive Supply Chain: The Case of Ethiopian Firms
Authors: Merhawit Fisseha Gebremariam, Yohannes Yebabe Tesfay
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This study focuses on the formulation of a sustainable, effective, and efficient supply chain strategy framework that will enable Ethiopian privatized firms. The study examined the role of privatization in productive sourcing, production, and delivery to Ethiopian firm’s performances. To analyze our hypothesis, the authors applied the concepts of Key Performance Indicator (KPI), strategic outsourcing, purchasing portfolio analysis, and Porter's marketing analysis. The authors selected ten privatized companies and compared their financial, market expansion, and sustainability performances. The Chi-Square Test showed that at the 5% level of significance, privatization and outsourcing activities can assist the business performances of Ethiopian firms in terms of product promotion and new market expansion. At the 5% level of significance, the independent t-test result showed that firms that were privatized by Ethiopian investors showed stronger financial performance than those that were privatized by foreign investors. Furthermore, it is better if Ethiopian firms apply both cost leadership and differentiated strategy to enhance thriving in their business area. Ethiopian firms need to implement the supply chain operations reference (SCOR) model for an exclusive framework that supports communication links the supply chain partners, and enhances productivity. The government of Ethiopia should be aware that the privatization of firms by Ethiopian investors will strengthen the economy. Otherwise, the privatization process will be risky for the country, and therefore, the government of Ethiopia should stop doing those activities.Keywords: correlation analysis, market strategies, KPIs, privatization, risk and Ethiopia
Procedia PDF Downloads 6611 Driving Forces of Bank Liquidity: Evidence from Selected Ethiopian Private Commercial Banks
Authors: Tadele Tesfay Teame, Tsegaye Abrehame, Hágen István Zsombor
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Liquidity is one of the main concerns for banks, and thus achieving the optimum level of liquidity is critical. The main objective of this study is to discover the driving force of selected private commercial banks’ liquidity. In order to achieve the objective explanatory research design and quantitative research approach were used. Data has been collected from a secondary source of the sampled Ethiopian private commercial banks’ financial statements, the National Bank of Ethiopia, and the Minister of Finance, the sample covering the period from 2011 to 2022. Bank-specific and macroeconomic variables were analyzed by using the balanced panel fixed effect regression model. Bank’s liquidity ratio is measured by the total liquid asset to total deposits. The findings of the study revealed that bank size, capital adequacy, loan growth rate, and non-performing loan had a statistically significant impact on private commercial banks’ liquidity, and annual inflation rate and interest rate margin had a statistically significant impact on the liquidity of Ethiopian private commercial banks measured by L1 (bank liquidity). Thus, banks in Ethiopia should not only be concerned about internal structures and policies/procedures, but they must consider both the internal environment and the macroeconomic environment together in developing their strategies to efficiently manage their liquidity position and private commercial banks to maintain their financial proficiency shall have bank liquidity management policy by assimilating both bank-specific and macro-economic variables.Keywords: liquidity, Ethiopian private commercial banks, liquidity ratio, panel data regression analysis
Procedia PDF Downloads 9610 Efficient L-Xylulose Production Using Whole-Cell Biocatalyst With NAD+ Regeneration System Through Co-Expression of Xylitol Dehydrogenase and NADH Oxidase in Escherichia Coli
Authors: Mesfin Angaw Tesfay
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L-Xylulose is a potentially valuable rare sugar used as starting material for antiviral and anticancer drug development in pharmaceutical industries. L-Xylulose exist in a very low concentration in nature and have to be synthesized from cheap starting materials such as xylitol through biotechnological approaches. In this study, cofactor engineering and deep eutectic solvent were applied to improve the efficiency of L-xylulose production from xylitol. A water-forming NAD+ regeneration enzyme (NADH oxidase) from Streptococcus mutans ATCC 25175 was introduced into E. coli with xylitol-4-dehydrogenase (XDH) of Pantoea ananatis resulting in recombinant cells harboring the vector pETDuet-xdh-SmNox. Further, three deep eutectic solvents (DES) including, Choline chloride/glycerol (ChCl/G), Choline chloride/urea (ChCl/U), and Choline chloride/ethylene glycol (ChCl/EG) have been employed to facilitate the conversion efficiency of L-xylulose from xylitol. The co-expression system exhibited optimal activity at a temperature of 37 ℃ and pH 8.5, and the addition of Mg2+ enhanced the catalytic activity by 1.19-fold. Co-expression of NADH oxidase with XDH enzyme resulted in increased L-xylulose concentration and productivity from xylitol as well as the intracellular NAD+ concentration. Two of the DES used (ChCl/U and ChCl/EG) show positive effects on product yield and the ChCl/G has inhibiting effects. The optimum concentration of ChCl/U was 2.5%, which increased the L-xylulose yields compared to the control without DES. In a 1 L fermenter the final concentration and productivity of L-xylulose from 50 g/L of xylitol reached 48.45 g/L, and 2.42 g/L.h respectively, which was the highest report. Overall, this study is a suitable approach for large-scale production of L-xylulose from xylitol using the engineered E. coli cell.Keywords: Xylitol-4-dehydrogenase, NADH oxidase, L-xylulose, Xylitol, Coexpression, DESs
Procedia PDF Downloads 229 Dairy Value Chain: Assessing the Inter Linkage of Dairy Farm and Small-Scale Dairy Processing in Tigray: Case Study of Mekelle City
Authors: Weldeabrha Kiros Kidanemaryam, DepaTesfay Kelali Gidey, Yikaalo Welu Kidanemariam
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Dairy services are considered as sources of income, employment, nutrition and health for smallholder rural and urban farmers. The main objective of this study is to assess the interlinkage of dairy farms and small-scale dairy processing in Mekelle, Tigray. To achieve the stated objective, a descriptive research approach was employed where data was collected from 45 dairy farmers and 40 small-scale processors and analyzed by calculating the mean values and percentages. Findings show that the dairy business in the study area is characterized by a shortage of feed and water for the farm. The dairy farm is dominated by breeds of hybrid type, followed by the so called ‘begait’. Though the farms have access to medication and vaccination for the cattle, they fell short of hygiene practices, reliable shade for the cattle and separate space for the claves. The value chain at the milk production stage is characterized by a low production rate, selling raw milk without adding value and a very meager traditional processing practice. Furthermore, small-scale milk processors are characterized by collecting milk from farmers and producing cheese, butter, ghee and sour milk. They do not engage in modern milk processing like pasteurized milk, yogurt and table butter. Most small-scale milk processors are engaged in traditional production systems. Additionally, the milk consumption and marketing part of the chain is dominated by the informal market (channel), where market problems, lack of skill and technology, shortage of loans and weak policy support are being faced as the main challenges. Based on the findings, recommendations and future research areas are forwarded.Keywords: value-chain, dairy, milk production, milk processing
Procedia PDF Downloads 318 India’s Developmental Assistance in Africa: Analyzing India’s Aid and Developmental Projects
Authors: Daniel Gidey, Kunwar Siddarth Dadhwal
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By evaluating India's aid systems and ongoing development initiatives, this conference paper offers light on India's role as a source of developmental assistance in Africa. This research attempts to provide insights into the developing landscape of foreign aid and development cooperation by focusing on understanding India's motivations and strategy. In recent years, India's connection with Africa has grown significantly, driven by economic, political, and strategic reasons. This conference paper covers India's many forms of aid, including financial, capacity building efforts, technical assistance, and infrastructure development projects, via a thorough investigation. The article seeks to establish India's priorities and highlight the possible impacts of its development assistance in Africa by examining the industries and locations of concentration. Using secondary data sources, the investigation delves into the underlying goals of India's aid policy in Africa. It investigates whether India's development assistance is consistent with its broader geopolitical aims, such as access to resources, competing with regional rivals, or strengthening diplomatic ties. Furthermore, the article investigates how India's aid policy combines the ideals of South-South cooperation and mutual development, as well as the ramifications for recipient countries. Furthermore, the paper assesses the efficacy and sustainability of India's aid operations in Africa. It takes into account the elements that influence their success, the problems they face, and the amount to which they contribute to local development goals, community empowerment, and poverty alleviation. The study also focuses on the accountability systems, transparency, and knowledge transfer aspects of India's development assistance. By providing a detailed examination of India's aid endeavors in Africa, the paper adds to the current literature on international development cooperation. By offering fresh insights into the motives, strategies, and impacts of India's assistance programs, it seeks to enhance understanding of the emerging patterns in South-South cooperation and the complex dynamics of contemporary international aid architecture.Keywords: India, Africa, developmental assistance, aid projects and South-South cooperation
Procedia PDF Downloads 627 Trends of Cancer Patients Who Underwent Curative/radical Radiotherapy at Radiotherapy Center, Tikur Anbessa Specialized Hospital
Authors: Emeshaw Damtew Zebene, Edom Seife, Hagos Tesfay, Gurja Belay
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Background: cancer incidence and mortality has grown rapidly throughout the world. Aging of the population, urbanization, physical inactivity, economic growth followed by smoking and drinking contributed a lot for the increased incidence of cancer all over the globe. Objective: the aim of this study was to assess a one-year trend of cancer patients who underwent curative/radical radiotherapy at radiotherapy center, Tikur Anbessa specialized hospital, Ethiopia. Methodology: We performed a prospective descriptive study of cancer patients treated with LINAC at Tikur Anbessa specialized hospital, Addis Ababa, Ethiopia, from April 2021- March 2022. A standardized questionnaire was used to collect sociodemographic and clinical characteristics of the patients. Descriptive statistics and chi-square results were generated using SPSS version 24. The level of significance was obtained at 0.05. Results: Sixty-four (64) curative/radical patients-44 females and 20 males were analyzed. Majority, 27(42.2%), of the patients age range from 45 to 64, and 45(70%) of them were urban residents where a group of higher gynecologic cancer was observed.78% of the patients were with locally advanced cancer, and 54(84.4%) of them had no awareness about cancer. Generally, head & neck cancer were found the most prevalent cancer 20(31.3%), and the leading cause of cancer among women was cervical cancer 17(38.6%), where about half 7(15.9%) of them were HIV positive. Conclusion: Our finding revealed that most of curative/radical patients presented at a locally advanced stage of the disease. Hence, maintaining the already available teletherapy machines and installing additional radiotherapy centers may help in treating the patients at the early stage of the disease. Since almost all of our study participants did not have information about cancer, awareness raising mechanisms should be done. Additionally, understanding differences in cancer incidence between urban and rural is important. Key words: Cancer, Curative/radical, Radiotherapy, Tikur Anbessa Specialized HospitalKeywords: cancer, curative/radical, radiotherapy, tkur anbessa specialized hospital
Procedia PDF Downloads 806 Nine Year Trend Analysis of Malaria in Kahsay Abera General Hospital Humera Town: Western Tigrai, Northern Ethiopia: A Retrospective Study
Authors: Getachew Belay, Getachew Kahsu, Brhane Berhe, Kebede Tesfay, Fitsum Mardu, Nigus Shishay, Hadush Negash, Aster Tsegaye
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Background: Malaria kills million people around the world, and it is still a serious public health problem in Ethiopia. Over the past years, the disease has been consistently reported as leading cause of outpatient visits, hospitalization and death in health facilities across the country. This study assessed malaria trend in Humera Town Kahsay Abera Hospital Tigrai region, Northern Ethiopia. Method: A Health facility retrospective cross sectional study was conducted in Kahsay Abera General Hospital from January 2011 to December 2019. Data of Malaria cases were reviewed from Health Management Information System with the help of experts in the office. The nine year data were extracted and analyzed using Excel by excluding those which lack demographic data. Result: A total of 36,604 smear positive malaria cases were confirmed in last nine years in the study area. Plasmodim falcifarum was the most prevalent reported species. Higher number of malaria cases were reported during October season.Males were more infected by the disese (63.1%) than females and males aged 15 years and above were the most iffected ones. The percentage proportion of P.falcifarum and P.vivax were 61.6% to 38.4%, respectively. There was a decreasing trend over the nine years following the peak in 2013. Conclusion: Malaria smear positivity, with highest cases being recorded in October, was declined over the nine years after peaking in 2013. Males aged 15 years and above were more affected, and P falciparum was the predominat species. Strengtheing the prevention and control activities is warranted in the study area.Keywords: trend, malaria, kahsay abera general hospital, tigray, ethiopia
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