Ethiopia Institute of Technology- Mekelle

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An Assessment of Integration Levels and Implementation Challenges in Smart City Development: The Case of Mekelle City, Ethiopia.
(Mekelle University, 2025-06-20) Zemichael Hailemariam Gebrihet
The aspiration to develop smart cities is seen globally as a strategic solution to urbanization challenges, aiming to improve infrastructure and enhance the quality of life. In developing countries, the potential for smart cities is high, but significant challenges hinder successful implementation. Smart, sustainable city development in developing countries is not as closely studied as it has been in developed countries. Furthermore, academic studies about smart sustainable city development preparedness have been applied largely to the narrow context of developed countries. This study is an effort to help fill that gap. This study focuses on Mekelle City as a case study to assess the extent of smart city development, the integration and implementation challenges faced, and assessment to overcome these challenges. The research adopts a multi-method approach, including a comprehensive literature review, surveys and interviews with key informants, and field observations. Both qualitative and quantitative analyses were conducted using tools like SPSS, supported by materials such as questionnaires, interview guides, and access to relevant documentation in Mekelle. The findings aim to provide valuable insights into overcoming the barriers that developing countries face in their efforts to build sustainable, livable smart cities. The study identifies several key challenges: limited financial resources, deficiency of coordination and externalities, governance inefficiencies or lack of public-private partnerships, lack of smart city operational framework, lack of system integration and sustainable focused strategies, and a lack of integration between technology and urban planning. To address these issues, strategic solutions are proposed, including raising revenues and diversifying financing sources for smart city development, stepping up the effort to fulfil basic infrastructure needs, constructing regulatory frameworks for smart city governance, creating a supportive ecosystem that nurtures start-ups and strengthening public private partnerships, promoting public-private partnerships, and improving policy frameworks. The study concludes that, while Mekelle faces significant hurdles, it has the potential to achieve sustainable smart city development. By implementing socioeconomic, human, legal, and regulatory reforms and focusing on innovation, capacity building, and governance, Mekelle can serve as a model for smart city development in developing regions, particularly in the Tigray region.
An Evaluation of structural Plan spatial Implementation in Abiy-Adi town, Tigray, Ethiopia
(Mekelle University, 2025-06-22) Masho Gebremichael
The research is intended to investigate the Challenges of structural Plan Implementation in the case of Abiy-Adi town, Tigray region and how it has been performing in relation to the performance criteria's such as, economic efficiency, environment, social equity .The formation and performance of urban structures are central issues in urban design and planning. The research is significant because it provides facts and figures on the Challenges of structural Plan Implementation in the case of Abiy-Adi town and its impact the current development trend on the performance of urban spatial structures (land use pattern) related to socio- economic, environmental and administrative issues of the town. A case study method was used for the investigation. Study cases which were established in different periods were taken and investigated against data methods. In addition the research attempts to find out how the land-use pattern of the town, like the commercial centers (the CBD), the residential, industrial areas, and the road structure existed. The study begins by collecting and identifying the challenges of the structure plan implementation of the town in its legal duration of the plan from the recent consecutives duration of the plan (2009-2019).As a result the study has found that lack of professional skills, lack of clear rules and regulations, lack of budget and materials, corruption and political intervention are among the major challenges of structural plan implementation in the town. Therefore, attention needs on monitoring the performance of plans implementation, follow up, land bank and land use change permeation from the town council must practiced
ANALYSIS & DESIGN OF STEEL WIND TURBINE TOWER UNDER COMBINED EFFECT OF WIND LOAD AND EARTHQUAKE
(Mekelle University, 2020-08-09) Negassi G/kidan
Artificial Neuro-Fuzzy Inference System (ANFIS) Based Speed Control of Separately Excited DC Motor for Load Torque Variations
(Mekelle University, 2025-09-09) Kibrom Zerau
Separately excited direct Motor (SEDCM) is an electromechanical actuator used to power different loads across several industrial and domestic applications. One fundamental characteristic for controlling when driving is the motor's speed. The external load linked to the drive negatively impacts speed if the controller is weak and the load varies. Objective of this thesis work is to design an Artificial Neuro-Fuzzy Inference System (ANFIS)-based speed control mechanism for a separately excited DC motor under varying load torque conditions. The ANFIS controller integrates neural networks and fuzzy logic to improve motor speed regulation, ensuring robust performance despite disturbances in load torque. Additionally, this this work explores the effectiveness of armature voltage control (source voltage adjustment) for dynamically regulating motor speed, comparing its performance with conventional control strategies. ANFIS, fuzzy logic controllers, PID controllers, and open loop (without controller) have all been used to measure the speed of an independently stimulated SEDC motor. At first, the motor speed can be regulated and modified by changing the armature voltage (the input supply voltage).When the torque of the load grows and the transient and steady state faults rise, the motor's speed falls in the absence of a controller. The motor performs poorly as a result, and its speed will not maintain its rated level. A PID controller improves the motor's speed over an open loop, but the overall performance is still poor and there are still some transient and steady state issues. Although fuzzy logic controllers perform better than PID controllers in terms of system performance, the speed still fluctuates as the torque of the load changes. However, ANFIS better than fuzzy, PID, and open loop control systems, operates at its rated speed, has low steady state and transient errors, and keeps the motor's speed constant as the load increases. In conclusion, NFIS is superior to fuzzy and PID controllers due to its zero overshoot and reduced 38.31% settling time compared to fuzzy and 50.93 % compared to PID, reduced 37.12% rise time compared to fuzzy and 44.87 % compared to PID, and reduced 85% steady-state error compared to fuzzy and 98.5 % compared to PID. Additionally, by resolving the motor's nonlinear properties, the system's overall performance will improve.
Assessing the Impact of Improper Sidewalks on Pedestrian Safety and Level of Service in Mekelle City
(Mekelle University, 2025-07-22) Kibrom Weldu
Pedestrian safety is a vital yet often neglected aspect of urban development in rapidly growing cities like Mekelle, Ethiopia. This study examines how improper sidewalk conditions, such as narrow, obstructed, and poorly maintained paths affect pedestrian safety and the Pedestrian Level of Service. A mixed-methods approach was used to comprehensively assess pedestrian conditions in Mekelle City. Quantitative data collection involved measuring sidewalk widths, counting pedestrians, and conducting structured surveys to evaluate safety, usability, and infrastructure quality. Physical assessments also identified common obstructions like vendors, utility poles, and parked vehicles. PLOS was evaluated using the Highway Capacity Manual, considering factors such as surface condition, lighting, and crossing points. Complementing this, qualitative data were gathered through field observations and open-ended survey responses to capture pedestrian experiences, perceptions of safety, and challenges such as poor lighting, unmarked crossings, and obstructed walkways, especially during nighttime travel. The findings show that most sidewalks are narrower than the recommended 1.2 meters and often obstructed by vendors, poles, or construction materials, making them unsafe. PLOS ratings ranged from C to E, indicating poor walking conditions. Over half of respondents felt unsafe, mainly due to poor lighting, inadequate crossings, and lack of maintenance. This study concludes that Mekelle's pedestrian infrastructure significantly hinders walkability and compromises safety. Recommendations include adopting international design standards, enforcing clear regulations to prevent sidewalk encroachment, and incorporating inclusive urban design principles in future planning. These insights provide essential guidance for urban planners and policymakers aiming to create safer, more accessible pedestrian environments in Mekelle and similar urban contexts.
Assessment and Design of Suitable Flood protection work at the Downstream of Gereb Burka River, Southern Tigray
(Mekelle University, 2025-09-05) TESFAY HAILU
Flooding along the downstream section of the Gereb Burka River in Southern Tigray's Raya Azebo Wereda near Mekoni city poses significant risks to communities and infrastructure. This study proposes flood defense measures to mitigate these hazards through gabion structural interventions. Hydrological analysis was conducted using rainfall data from the Maichew meteorological station (1993–2019), applying methods for missing data estimation, adequacy testing, and outlier detection. The Soil Conservation Service Curve Number (SCS-CN) method was employed to estimate runoff, considering land use/land cover and hydrologic soil groups (CN = 86 for AMC III). Peak discharge was calculated as 234.5 m³/s for a 25-year return period, with a probable maximum rainfall of 80 mm derived from log-normal distribution analysis. Gabion structures were identified as the most suitable flood defense mechanism due to their cost effectiveness, adaptability, and compatibility with the erosion-prone, semi-arid conditions of the region. A detailed stability analysis confirmed the structural integrity of the proposed gabion design, with factors of safety against overturning (>4.1), sliding (>1.6), and bearing capacity failure (>7.6) meeting engineering standards. The design includes a 2.2 m-high gabion wall with a 73 m waterway width. This research provides a practical solution for flood mitigation in the study area and serves as a reference for similar projects. Recommendations emphasize regular maintenance of flood defenses, community awareness programs, watershed reforestation, and further studies on sediment management to enhance long-term resilience. The project underscores the importance of integrating hydrological and geotechnical analyses in flood protection planning.
Assessment and evaluation of hydraulic parameters in Raya irrigation pumping wells
(Mekelle University, 2025-09-05) Samiel Gigar
The Raya well field located in the northern part of Ethiopia, southern part of Tigray region and have raised concerns with respect to the ability of the aquifer system to sustain production. As the aquifer of Raya well field in particular is heavily used in this area, understanding the hydraulic parameters of the area is essential for efficient sustainable management of the groundwater resource. An overview of the hydraulic parameters estimated for the 22 pumping irrigation wells in the study clearly show strong evidence of inappropriate estimation. Thus, this study was conducted to identify the possible miss-interpretation of the observed time-drawdown, step drawdown, time residual drawdown-based hydraulic parameter estimation. After data quality checking, appropriate data correction for partial penetration, well loss and unconfined aquifer were conducted. Then the standard methods like Theis curve fitting, Cooper-Jacob methods for time drawdown data & Theis recovery method for time-residual drawdown data were used for parameter estimation. Beside Aquifertest v8.0 software was also used to verify the results of the original study. Evaluation and analysis result showed that out of the 22 well analyzed, 15 transmissivity values used in the well yield estimate were overestimated (0.22 up to 29.23 percent) and 6 underestimated (0.26 up to 1700.72 percent) the other one well has not stated transmissivity value, such highly overestimated transmissivity value misleads the designers & operators in fixing the well yield, 15-25% cost overrun, Poor water supply reliability, planning inequity and trust erosion with the client or society and reduce the life span of the pumping wells by 26-62 percent. Additionally, from 22 pumping wells 18 or 81.81 percent out of the total sample wells have not efficiency stated in the design documents. The minimum efficiency of irrigation wells should be 60%, considering this minimum irrigation wells efficiency limit 3 pumping wells have efficiency greater than 60 percent this is around 13.63 percent the others 19 pumping wells have less than 60 percent efficiency, this is around 86.36 percent. The storativity of unconfined aquifer is 0.1-0.3 and the storativity of confined aquifer is 0.005-0.00005. data from Tigray office of water resources and energy shown that the storativity of the 13 wells are far away from the range whereas 2 wells are slightly out of the range. The rest 7 wells have not storativity stated in the document. results from this research computations shown that the storativity of the 14 wells are far away from the range, whereas 7 wells are slightly out of the range. The rest 1 well falls within the range or accepted. the reason behind this large error in storativity value is the wells are only pumping or production wells, for accurate and precise storativity computation an observation well is very mandatory. The recommendation for the less efficiency is to Reduce the pumping rate or Optimize Pumping Operation. Results also shown that most of the irrigation pumping wells fall on the category of class of transmissivity magnitude “II” and fall on the “high” designation of transmissivity magnitude. a well pumped for 18 hours per day and for 120 days in a year it can lead to cumulative land subsidence from 0.009 meter or 9 mm up to 0.056 or 56 mm per year. Therefore, in this evaluation it is recommended to conduct multiple well test to determine the actual hydraulic parameters of the aquifer in order to obtain the safe yield of the wells which is intended to prolong the productivity of the aquifer and to delay excessive loss of saturated thickness.
Assessment of the Performance and Challenges of Public Procurement of Works in Semera, Afar National Regional State
(Mekelle University, 2025-09-25) Ali Amin Ibrahim
Public procurement is a pivotal mechanism linking project aspirations to the delivery of quality infrastructure. In Semera, Afar National Regional State, despite substantial investment in public works, procurement outcomes have often fallen short of expectations. This study assessed thirty public works projects implemented between 2018 and 2023, revealing systemic inefficiencies, delays, and quality shortfalls. Only 58% of projects complied with national procurement guidelines, procurement cycles averaged 6.5 months, and cost overruns affected 40% of projects, with an average escalation of 18% above contract values. Time and quality performance were also suboptimal, with less than half of projects completed on schedule and only 60% meeting technical standards. The analysis identified several institutional and market-related challenges undermining procurement performance. Capacity constraints were significant, with 72% of procurement staff lacking formal training and high turnover reducing continuity. Planning weaknesses were widespread, as 65% of procurement plans were delayed or incomplete, often without adequate market analysis. Transparency and accountability were insufficient: only half of tenders were openly advertised and nearly a third lacked complete bid evaluation reports. Market limitations further constrained performance, with an average of only three bidders per tender and contractor capacity often insufficient, resulting in project suspensions or abandonment. The consequences of these challenges were evident in persistent cost overruns, project delays, and compromised quality, particularly in essential infrastructure such as schools, roads, and health centers. Stakeholder confidence in procurement was low, with 68% rating performance as ineffective. These systemic weaknesses reduce the value for money and delay the delivery of public services, highlighting the urgent need for institutional reforms and operational improvements in public procurement practices in Semera. To address these gaps, the study recommends capacity building, improved planning, enhanced transparency, stronger oversight and accountability, and support for local contractors. Implementing these reforms will enhance efficiency, cost-effectiveness, and quality in public works, promoting sustainable economic development in Afar.
Comparative Analysis of Passive, PID And Fuzzy_PID Controller For Quarter Car Model
(Mekelle University, 2025-09-15) Atsede Gebreyohans
This paper presents a comparative analysis of passive, PID, and fuzzy PID control strategies for a quarter-car suspension system utilizing a fuzzy PID controller to enhance ride comfort and stability by effectively managing displacement and velocity. The quarter-car model serves as a simplified representation of vehicle dynamics, where the primary objective is to minimize the vertical displacement of the vehicle body and control the relative velocity between the body an the wheel. Additional PID controllers often struggle with non-linearity and uncertainties present in suspension systems; therefore, it is proposed a fuzzy logic approach to tune the PID parameters dynamically based on real-time system states. The fuzzy-PID controller integrates the benefit of fuzzy logic’s ability to handle uncertainty and the robustness of classical PID control. Simulation results demonstrate that the proposed fuzzy-PID versus passive controller significantly reduces body displacement by 88％of overshoot and 56％of settling time with bumpy input road1. Fuzzy-PID versus passive controller significantly reduces velocity response by 24％of overshoot and 55％of settling time with bumpy input road1.
COMPARATIVE PERFORMANCE ANALYSIS OF LQR, PID, FUZZYPSO AND PSO-PID CONTROLLERS ON QUARTER CAR ACTIVE SUSPENSION SYSTEM
(Mekelle University, 2025-04-05) KOKEB GEBREMEDHIN
The purpose of this study is to evaluate and compare the effectiveness of various control strategies for active suspension. MATLAB/SIMULINK software is used for both the controller design and the quarter vehicle model. The control strategies PID, LQR, PSO-PID, and FUZZY-PSO are employed. The suspension travel response and sprung mass acceleration response two critical parameters for ride comfort and road handling are chosen, examined, and compared between the responses of the active suspension system and the passive suspension system in order to assess the effectiveness of the vehicle's suspension system. The two Key Performance Indicators (𝐾𝑃𝐼𝑀𝐴𝑋 𝑎𝑛𝑑 𝐾𝑃𝐼𝑀𝐴𝑋) are chosen to demonstrate a decrease in peak overshoot and a decrease in oscillation for the parameters chosen for the active and passive suspension system comparison. From this research, in summary, the PSO-PID and FUZZY-PSO controllers that were created exhibit exceptional performance in enhancing ride quality, hence increasing passenger safety and vehicle handling in the presence of two bumpy road disturbances. When it comes to decreasing to sprung mass acceleration and suspension travel, the PSO-tuned fuzzy logic controller performs the best, followed by PSO-PID, LQR, and PID controllers.
Design and Analysis of Solar water pumping system for Agricultural Farming of Sweet Potato
(Mekelle University, 2025-04-07) Tsegabrhan Gebretsadkan
Quality of life, sustainable development, and economic progress are all largely influenced by energy. The shift to renewable energy sources has become essential in light of the growing global energy crisis, which is characterized by rising demands and the depletion of fossil fuel resources. Solar energy is one of the most promising of these, especially when it comes to solving important issues with agricultural methods.The design and study of a solar photovoltaic (PV) irrigation pumping system for sweet potato growing in the Abraha-Atsbeha hamlet are the focus of this thesis. Because they rely on expensive and environmentally damaging diesel pumping equipment, local farmers today confront many challenges. To address these challenges, the research begins with a comprehensive review of existing literature on solar irrigation technology, identifying key gaps and challenges in the field. Building on this foundation, a conceptual design for the PV irrigation system is developed, incorporating essential components such as the PV array, pump, storage tank, and control systems tailored to the specific needs of sweet potato cultivation. A detailed computer model of the proposed system is created and simulated using advanced software tools, including CROWAT, MATLAB, PSIM, HOMER, PVSyst, EasyEDA, and Drawing.io. Benchmarking exercises are conducted to evaluate the system's efficiency across varying climatic conditions by adjusting parameters like temperature and solar irradiance. The findings highlight the effectiveness of the Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) algorithm in optimizing power output and ensuring efficient operation. According to the results, the Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) algorithm is a good way to maximize power output and operational efficiency. In summary, a comparative study shows that the solar-powered irrigation system has several benefits over conventional diesel systems, such as decreased carbon emissions and operating expenses. The potential of solar technology to revolutionize farming methods, enhance food security, and support a sustainable energy emphasized by is this study
Design and Experimental Evaluation of passive Solar Still under hottest and driest climate condition of Ethiopia: A case of lake-Afdera saline water
(Mekelle University, 2024-12-25) Mohammed Ahmed Yasin
Access to potable water remains a critical challenge globally, particularly in arid regions such as Ethiopia's Afar Region, where groundwater is often limited or contaminated with high levels of fluoride and salinity. This study investigates the design and performance of passive solar stills for desalinating saline water from Lake Afdera under extreme climatic conditions. The objective was to enhance the productivity of conventional single-slope, single-basin solar stills by incorporating black volcanic rocks as thermal energy-absorbing materials. Two solar still configurations a conventional design and a modified design with black volcanic rocks were constructed and experimentally evaluated over two days in Afdera. Parameters such as ambient temperature, water temperature, and hourly yield were recorded. To validate the results, the modified still was later tested under different environmental conditions at Mekelle University using thermocouples, PicoLog software, a pyranometer, and measuring jars for precise data collection. Results showed that the modified solar still significantly outperformed the conventional still in water yield, producing 3,482 ml and 3,800 ml over two days compared to 1,920 ml and 1,780 ml, respectively. It also demonstrated improved night-time performance, yielding 890 ml versus 340ml, due to better heat retention from the black rocks. Correlation analysis from the Mekelle validation indicated strong relationships between water yield and solar radiation (r = 0.60), rock temperature (r = 0.96), internal temperature (r = 0.85), and ambient temperature (r = 0.83). The modified system achieved 32.87% higher efficiency in Afdera than in Mekelle, highlighting the role of environmental conditions. The findings confirm that integrating black volcanic rocks into solar still design enhances efficiency and output, offering a cost-effective and sustainable desalination solution for arid, high radiation regions like Afar.
Design and Numerical Analysis of a Solar-Based Thermal Energy Storage System for Industrial Hot Water: A Case Study at Addis Pharmaceutical Factory (APF)
(Mekelle University, 2025-07-01) Eyob Kahsay
Solar thermal energy storage (TES) provides a sustainable solution to growing energy demands by storing excess solar energy for later use, particularly in regions with high solar availability. With rising fuel costs and increasing greenhouse gas emissions, adopting energy efficiency improvements and integrating renewable energy sources are crucial in our country, Ethiopia. At APF, furnace oil consumption for process heating is substantial. Additionally, air conditioning (HVAC) systems and process heating rely on hot water produced by an indirect furnace oil system. In this setup, steam is generated in a boiler and then used to produce hot water through a heat exchanger. This is due to water being preferred over steam for certain applications it is easier to control. At APF, 32.5% of the total furnace oil consumption is allocated for hot water production, resulting in an annual cost of approximately 2.88 million birr. This study focuses on the design, analysis, and modeling of a solar-powered TES system for hot water consumption at APF, aiming to enhance system efficiency by selecting the optimal heat transfer fluid (HTF) and energy storage material based on thermal performance and cost-effectiveness. The research evaluates three TES methods: sensible, latent, and thermochemical storage. While phase change materials (PCMs) offer high energy storage density, they have material limitations. Sensible heat storage, despite being cost-effective, has a low heat capacity, making storage units impractically large. Chemical heat storage, though providing high storage density, is hindered by complex reactor designs and stability concerns. Key parameters such as HTF mass flow rate, heat transfer coefficient, flow velocity, and Reynolds number were calculated. The study also includes thermal design analysis, Computational modeling, and performance simulations. The results include calculations of boiler power, total energy consumption, water mass flow rate, energy storage capacity, and trough area. Additionally, SolidWorks geometric modeling was utilized to visualize the concept and aid in solution development. The findings demonstrate the potential of the designed TES system to improve energy efficiency, reduce operational costs, and lower greenhouse gas emissions, contributing to the advancement of sustainable thermal energy storage solutions. Based on comprehensive thermal analysis and ANSYS computational simulations, Shell Heat Transfer Oil S2 was identified as the most effective HTF, while Sodium Thiosulfate Pentahydrate was determined to be the optimal storage material for low- to medium temperature applications. Additionally, an optimal insulation thickness of 16 mm was found to minimize energy loss and cost. To mitigate the intermittent nature of solar energy, the TES system addresses the annual operating cost saving of 0.58 million birrs for the eight-hour operating period, which is 58.2 kW.
Design and Optimization of a Hybrid Polyester Composite for Bus Roof Plates Using Jute and Reused PET Fiber Reinforcement
(Mekelle University, 2025-05-19) Natnael Abera
The automotive sector faces rising fuel consumption and pollution due to the increasing vehicle numbers. To mitigate these challenges, lightweight materials have become imperative to diminish the weight of automotive components. Additionally, addressing the pervasive issue of plastic pollution necessitates innovative solutions, such as recycling or reusing the primary plastic pollutant, polyethylene terephthalate (PET). This study tackles two interconnected issues: reducing vehicular weight through material substitution and mitigating plastic waste by reusing PET from discarded water bottles. The main objective of this study is to design and optimise a hybrid polyester composite material for bus roof plates for the modified ISUZU NPR71 4570cc, utilizing jute and reused PET fibers as reinforcement. Samples were prepared using the hand lay-up method, with fiber-to-matrix weight fractions ranging from 40% to 60%. Five laminates were created, incorporating alkali-treated jute fibers to enhance interfacial adhesion. Through a series of experimental tests, the tensile, compressive, flexural, impact strengths, density, and water absorption rates were conducted. The TOPSIS method was applied to assess and evaluate the properties of prepared laminate samples. Results indicate that the P-J-J-P orientation of NaOH treated jute fiber stands out as the optimal choice. The NaOH-treated jute fiber reduces water absorption by 47% (1.13% compared to 2.13% for untreated jute). A hybrid composite with a PJ-J-P layup and a 0°-90°-0° orientation was used to design a bus roof plate, optimised using Hyper Works-Optistruct and validated through re-analysis with ABAQUS. The optimised jute/PET hybrid polyester composite roof plate achieved a 34.58% weight reduction compared to a mild steel plate, decreasing from 210.38 kg to 137.63 kg, and saved 0.2765 litres of fuel per 100 km. This demonstrates that jute/PET hybrid polyester composites can effectively replace steel structures, offering significant environmental benefits and fuel savings without compromising performance or vehicle load capacity.
Design and Optimization of Bamboo/Glass Fiber Reinforced Epoxy Composites for Sustainable Wall Panel Application
(Mekelle University, 2025-05-19) Amelewerk Halefom
The increasing demand for sustainable construction materials has driven interest in natural fiber reinforced composites as eco-friendly alternatives to conventional materials. This study focuses on the design and optimization of bamboo/glass fiber-reinforced epoxy composites for application in sustainable wall panels, aiming to achieve a balance between mechanical performances, weight reduction, improve water resistance and sustainability. Different stacking sequences (B-G-B, G-B-G, G-G-B, and B-B-B) of bamboo and glass fibers were fabricated using the hand lay-up technique, preparation of 40% fiber and 60% of epoxy matrix incorporating alkali-treated bamboo fibers to improve interfacial bonding. The mechanical and physical properties of the fabricated composites were experimentally determined according to ASTM standards. A multi-criteria decision-making approach, using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), was employed to identify the optimal composite configuration. And it tells that G-B-G, characterized by a stacking sequence comprising 30% Bamboo, 10% glass, 60% epoxy, stands out as the optimal choice. The structural behavior of the optimized wall panel design was analyzed using Classical Lamination Theory. The optimization process, incorporating a genetic algorithm in MATLAB, aimed to minimizing weight and the constraint function is Tsai-Wu failure criterion. It results weight of the composite is 23.04kg, which reduced weight of the plywood weight by 15%, gypsum board by 5.8% and concrete panel by 38.4% and brick by 36%. Using literature review optimization, the water absorption of composite is 2.98% which reduced water absorption of the plywood by 7.11% of the gypsum board dry well is 9.11%, and concrete panel 2.11%, brick panel reduce by 8%. The optimized results were validated using ABAQUS of FEA. The maximum stress obtained from Genetic algorithm is 4.466Mpa and the maximum Von Mises stress is 8.511Mpa. The maximum deformation of the composite laminate is 12.2mm. This is less than the ultimate strength, proving the composite wall panel is safe and shows the safety factor is 2.5 against failure. The results of this study contribute to the development of sustainable and high performance wall panels using locally available bamboo resources.
Design and Optimization of Bamboo/Glass Fiber Reinforced Epoxy Composites for Sustainable Wall Panel Application
(Mekelle University, 2024-11-12) Tedros Tilahun
Estimating the angle of arrival (AoA) of a coming signal can accomplished using various methods. In most cases algorithms are used for such purposes. However, algorithms are naturally complicated and expensive, and also cause a degradation in system performance. Therefore, other methods such as, 1800-hybrid rat race (HRR) coupler can be applied for effectively estimating the AOA of a coming signal. In this thesis work, an 1800 HRR coupler integrated with a 2x1 closely-spaced patch antenna array and a negative permeability metamaterial was studied for estimating AoA of a coming signal. The 1800 HRR was made up of a ring metallic sheet integrated with four additional branches placed at the edges of it. It operates at 10 GHz so as to make compatible with the 2x1 patch antenna array’s operating frequency. The simulation results show, the 1800 HRR coupler is characterized by 00- phase at the sum (Σ)-port while 1800 phase shift at the difference (Δ) port at the given operating frequency. In order to integrate with the 1800 HRR, a 2x1 array patch antenna with an inter - element distance of 0.6λ (where λ is the operating wave length) was designed. The antenna array workes at 10GHz with a maximum simulated gain of 8.824 dB while keeping the mutual coupling to a minimum of -23 dB. To further achieving miniaturization, the inter-element distance reduced to 0.4λ. The simulation result shows a resonance at 10 GHz frequency and maximum gain of 7.8 dB while the mutual coupling increased to -9 dB. The 2x1 patch antenna array with inter - element distance of 0.6λ -1800 HRR coupler system was able to estimate the AoA of the received signal from 00 to 190 with error of less than 50. While with a reduced inter – element distance to 0.4λ, the system was able to estimate signals from 00 to 500 with error of less than 50. Upon integrating split ring resonator (SRR) met materials, mutual coupling reduced to -15.6 dB without affecting the AOA of the system. This study was able to estimate AOA in a wide range of an incoming signal while keeping the inter – element distance smaller. The proposed design can be applied in radar system applications where accurate estimation of AOA of an incoming signal is needed such as in target tracking, surveillance, and navigation missions.
DESIGN AND SIMULATION OF SINGLE AXIS SOLAR TRACKER FOR IMPROVING THE EFCIENCY OF PARABOLIC CONCNTRATOR
(Mekelle University, 2025-04-07) Awet Welay Hadgu
This research explores the design, simulation, and analysis of an active single-axis solar tracking system aimed at addressing the challenges associated with optimizing the performance of parabolic solar concentrators. Solar concentrators, particularly parabolic designs, offer significant advantages in harnessing solar energy for thermal applications, yet their efficiency is highly dependent on precise solar tracking. The current study develops a robust system designed to improve tracking accuracy, withstand challenging environmental conditions, and enhance overall system performance. Finite Element Analysis (FEA) was employed to validate the system’s structural reliability under extreme wind speeds of up to 55 m/s, a critical factor for ensuring operational stability in windy regions like Ethiopia. Additionally, dynamic modeling and control system design were carried out using MATLAB/Simulink, where a PID controller was tuned for optimal tracking performance. Results from simulations showed that the system achieved a tracking accuracy of over 96%, with minimal errors even under disturbances. These findings underscore the importance of integrating advanced tracking mechanisms in renewable energy systems to maximize energy capture and utilization. By addressing key challenges identified in existing parabolic concentrators, this study contributes significantly to the body of knowledge on solar energy systems and presents a practical solution for enhancing their efficiency, particularly in resource-constrained settings like Ethiopia
Design of a Genetic Algorithm (GA) and Particle Swarm Optimization (PSO)-based Linear Quadratic Gaussian (LQG) regulator for a Series Double Inverted Pendulum on a Cart
(Mekelle University, 2024-04-11) Solomon Teklehaimanot
This thesis focuses on the design of a Genetic Algorithm (GA) and Particle Swarm Optimization (PSO)-based Linear Quadratic Gaussian (LQG) regulator for a Series Double Inverted Pendulum on a Cart (SDIPC). The primary issues motivating the design of this regulator are the unstable behavior of the SDIPC, the slow settling times, and the significant steady-state errors observed in previously designed regulators. For this plant model, the LQG is developed using a cascaded combination of a GA and PSO-tuned Linear Quadratic Regulator (LQR) and a full-state observer, based on the separation principle theory of control systems. This approach is optimal for fully stabilizing the SDIPC and can withstand process and measurement noise through a Kalman filter. The entire system is designed in MATLAB®/SIMULINK®. Simulation results demonstrate that the PSO-tuned LQG achieves faster settling times and smaller steady-state errors compared to the GA-tuned LQG. With the PSO-tuned LQG, the steady-state errors for the upper pendulum angle, lower pendulum angle, and cart position are reduced to 1.033 × 10⁻⁴ rad, 4.206 × 10⁻⁵ rad, and 2.920 × 10⁻⁴ m, respectively. Additionally, the settling times for the upper pendulum angle, lower pendulum angle, and cart position are 0.897 s, 0.711 s, and 0.780 s, respectively. Thus, the regulator design objectives are successfully achieved with the PSO-tuned LQG than with GAtuned LQG.
Design of an Adaptive Neuro-Fuzzy Inference System Controller for Temperature and Concentration Control in a MIMO Continuous Stirred Tank Reactor (CSTR)
(Mekelle University, 2025-04-07) Ybrah Zemcheal
The Continuous Stirred Tank Reactor (CSTR) is a critical unit in chemical processing industries, where precise control of process variables is essential for optimal product quality and efficiency. Among the key variables, temperature and concentration are particularly important to regulate. However, chemical processes often exhibit nonlinear and multivariable behavior, making conventional controllers less effective in real-time operation (PID control in CSTR exhibits sluggish or oscillatory responses for feed concentration, slow response to variable water flow, Poor robustness for uncertain parameters (e.g., reaction rates, heat transfer coefficients), perform poorly due to cross-coupling effects, less nonlinearity handling due to reaction kinetics. Challenges such as dynamic process variations, reactant nonlinearities, fluctuating environmental conditions, and diverse disturbances further complicate control. Additionally, most industrial chemical processes are multi-input multi-output (MIMO) systems, necessitating advanced control strategies and decoupling techniques. In this study, an Adaptive Neuro-Fuzzy Inference System (ANFIS) is proposed as an advanced control approach to enhance system performance and accuracy compared to conventional controllers. ANFIS integrates the structured knowledge representation of fuzzy logic with the adaptive learning capabilities of neural networks, offering improved control for complex systems. The performance of ANFIS is evaluated against a traditional PID controller through offline simulations using MATLAB/Simulink. The results demonstrate that ANFIS outperforms PID control in key performance metrics, including overshoot, rise time, settling time, and system stability. Furthermore, ANFIS exhibits superior disturbance rejection capabilities, making it a more robust solution for CSTR control in industrial applications.
Design of Fuzzy logic controller to series active variable geometry suspension system of automobile vehicle using full car model (With preview road profile information)
(Mekelle University, 2024-04-07) Binyam Tadros
Recent advancements in electro-mechanical active suspensions are presenting new opportunities, showcasing numerous benefits over traditional passive and semi-active systems, while also overcoming the significant drawbacks of other active solutions. This thesis introduces fuzzy logic controller with perfect preview information to improve the performance of Series Active Variable Geometry Suspension (SAVGS), which enhances conventional independent passive or semi-active suspensions by actively regulating the suspension geometry through an electromechanical actuator. The research work explores the benefits of this suspension type and provides an in-depth analysis of its simplest form. Additionally, it offers insights into the design process, including liberalized full-car modeling and selection. A control system designed to manage pitch and roll attitude of the chassis is also discussed. Simulation results demonstrate the viability of the proposed system as the fuzzy logic controller (FLC) is developed using MATLAB-Simulink for the SAVGS improves the suspension system, with various performance metrics (Passenger Ride Comfort, Suspension Safety, and Road Handling) evaluated at different speed for Road disturbance. The performance response at 20 kilometer per hour shows improvement in all the performance metrics, like in Passenger ride comfort is reduced in Vertical acceleration by 41.67% with reduced pitch and roll acceleration, Suspension safety is reduced in suspension deflection by 49.1% in front and 43.1% in rear sides with reduced velocity, and in road handling the tire deflection reduces by 46.3% at front and 36.9% at the rear sides of the car