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<rss version="2.0"> <channel> <title>International Journal of Engineering Research in Africa</title> <link>https://www.scientific.net/JERA</link> <description>Latest Results for International Journal of Engineering Research in Africa</description> <language>en-us</language> <image> <title>International Journal of Engineering Research in Africa</title> <link>https://www.scientific.net</link> <url>https://www.scientific.net/Image/JournalCover/17</url> </image> <item> <title>Investigation of Al2O3-Modified Aluminide on 304SS: Microstructural Evolution, Hardness and Growth Kinetic through Slurry Aluminizing</title> <link>https://www.scientific.net/JERA.72.1</link> <guid>10.4028/p-qPDN4Z</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Ibrahim Owolabi Ambali, Siew Min Tan, Muhamamad Afifi Jalaluddin, Abu Seman Anasyida, Tuti Katrina Abdullah, Brij Kumar Dhindaw The microstructure and growth kinetic of alumina (Al2O3)-modified aluminide coating were investigated at 650°C, 680°C, and 700°C for various durations (4, 6, 8, and 10 hours) using the slurry aluminizing process. The heat-treated samples were analyzed through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) to assess microstructural evolution, elemental composition, and phases of the coating. SEM observations revealed a two-layer aluminide coating, comprising an Al-rich intermetallic (FeAl3) and a Fe-rich intermetallic (FeAl). Microhardness tests showed that FeAl3 had hardness values ranging from 880 to 990 HV, while FeAl, with values between 610 and 700 HV. The growth kinetics indicated that the thickness of the aluminide layers increased with both the aluminizing temperature and time, following a parabolic growth law. The activation energy for the growth of FeAl was 343.15 kJ/mol. </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> <item> <title>Thermal Performance and Sensitivity Analysis of Permanent Magnet Motor: Theoretical Investigation and Optimization</title> <link>https://www.scientific.net/JERA.72.13</link> <guid>10.4028/p-DJ8bke</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Amany Nasr, Ebrahim Badran, Ibrahim Mansy The thermal model of a permanent magnet motor (PMM) is investigated in this study using the lumped parameter thermal approach to calculate temperature variation at steady-state and transient conditions. The temperature variation of the motor components over time under various loads is investigated. The proposed thermal model was constructed with the MATLAB code. The thermal characteristics of the motor are examined using the simulation results. The optimization and sensitivity analysis are done using the response surface method (RSM) by design expert software. It can be seen that increasing the load and time increases the temperature of all parts in the machine. Also, point multiplication with 0.998 desirability is presented, which has the best efficiency with the lowest temperature. </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> <item> <title>The Dynamics of the Inertial Conveyor</title> <link>https://www.scientific.net/JERA.72.35</link> <guid>10.4028/p-FiV8k6</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Leonid Serilko, Oleg Lyashuk, Zoia Sasiuk, Mariana Sokol, Dmitriy Serilko, Katerina Pryndiuk, Anna Tson, Taras Dzhyvak The paper presents the results of the study of bodies movement on a rough surface, which carries out longitudinal and transverse oscillations. The design of the inertial conveyor for reducing dynamic loads has been proposed. The dependences of the acceleration of the longitudinal oscillations of the chute and the speed of the transverse oscillations of the chute walls on dimensionless time τ=ωt have been obtained. As a result of the kinematic analysis of the mechanism of the reciprocating movement of the chute, the dependences of the movement, speed and acceleration of the chute of the inertial conveyor on the angle of rotation of the crank and its rotation frequency have been obtained. As a result of the conducted theoretical studies, it has established that when the chute of the inertial conveyor is given transverse oscillations during periods of time and when the load slides along the surface of the chute, the productivity of this vehicle significantly increases. The obtained dependencies can be used in the design of inertial conveyors with given technical and economic indicators. </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> <item> <title>Design and Analysis of Low-Cost and Efficient SEPIC Converter for Affordable Solar Water Pump in Ethiopia</title> <link>https://www.scientific.net/JERA.72.47</link> <guid>10.4028/p-3aNeSp</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Minyahil Tanashu, Tassew Tadiwos, Amare Kassaw, Seifu Admasu, Noam Ezra, Teng Long, Lara Allen, Elizabeth M. Tennyson, Sam Stranks, Tefera Yetayew Abstract. Smallholder farms provide a significant share of the world's food supply. Smallholder farmers can cultivate crops more consistently throughout the year when using solar water pumps, which offer a dependable source of irrigation. However, the upfront capital cost and efficiency are major barriers to widespread adoption. This paper aimed to design a cost-effective and efficient DC-DC converter for small-scale irrigation farming in the Dangishta, Amhara region of Ethiopia, focusing on a direct solar water pump system using a SEPIC-based DC-DC converter. The system directly supplies power to a 100 W/24 V brushless DC pump, with a 120 W/24 V/5 A optimized SEPIC converter. A PLECS simulation was conducted to understand the converter's operation. The prototype design considered enhanced power handling capabilities using the paralleling method. The power switches are controlled by a digital circuit based on the RP2040 microcontroller, which generates PWM signals with a fixed duty cycle at 100 kHz. The average material cost of the converter was significantly minimized to approximately $15. Experimental tests showed an efficiency of 93.5% and an average temperature of 31°C, making it a promising solution for sustainable agriculture in resource-constrained environments.Keywords— Smallholder farms, Low-cost, SEPIC converter, Solar water pump, PLECS </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> <item> <title>Numerical Analysis of the Spread of Solar Radiation Flux across Multiple Walls for a Living Area in Adrar Region</title> <link>https://www.scientific.net/JERA.72.71</link> <guid>10.4028/p-W9ZmIM</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Abdellatif Oudrane, Benaoumeur Aour, Nadhir Damba, Messaoud Hamouda, Rafik Belarbi This study aimed to determine the amount of solar radiation flux incident on the walls of a simple residential house located in an arid desert area. To this end, a preliminary model of the sun’s path throughout the whole day was made. A numerical code in the FORTRAN language was also developed. This code is based on numerical models to calculate all the astronomical quantities necessary to determine the values of the solar radiation flux mentioned above. After comparing and analyzing of the results obtained from this numerical code, it was found that the percentage of agreement between the calculated values and the values measured by the Renewable Energy Research Unit in Saharan Medium (URERMS) is very satisfactory. The error rate does not exceed 4% for the average outdoor temperature and the average global solar radiation flux for the selected typical day. </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> <item> <title>Review on Application of Rice Husk Ash for Production of Hollow Sandcrete Blocks: Towards Sustainable Construction</title> <link>https://www.scientific.net/JERA.72.97</link> <guid>10.4028/p-Zqj5YL</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Mukaila Abiola Anifowose, Akeem Ayinde Raheem The search for cement substitutes will significantly lower building costs and contribute to a decrease in greenhouse gas emissions from cement production. In mortar and concrete, rice husk ash (RHA) has been extensively researched as a partial cement substitute. The improper usage and disposal of recyclables (rice husk and RHA) produced during rice production is one of the main issues that negatively impact the rice industry. One way to address this is by incorporating waste into construction materials. In this study, past research on sandcrete blocks was reviewed to ascertain the suitable use of RHA for producing sandcrete blocks for sustainable construction. Specific gravity, oxide compositions, X-ray diffraction (XRD), and scanning electron microscopy (SEM) of RHA were reviewed, while strength comparisons between conventional blocks and RHA-blocks were also reviewed. The physio-chemical outcome of the RHA revealed it as a good binding material. The study concluded that hollow sandcrete blocks produced with RHA could be used as non-load-bearing walls and for lightweight construction. Hence, the fineness of RHA and the longer curing age of blocks will determine RHA’s usefulness for producing load-bearing walls. The application of RHA for producing hollow sandcrete blocks will lead to sustainable construction, thereby reducing environmental pollution posed by the rice industry. </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> <item> <title>Mechanical, Thermal Stability, and Shielding Properties of Slag/Granite Geopolymer Cement Modified by Nanoparticles</title> <link>https://www.scientific.net/JERA.72.117</link> <guid>10.4028/p-JZ9BzZ</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Fayza S. Hashem, Ahmed T. Abdel Salam, Dalia Monir In this study, we developed alkali-activated geopolymer cement (GP) using finely powdered granite waste (GW), blast furnace slag (BFS), and nano-silica (NS). NaOH and Na2Si2O3 (1:1) were used as an alkaline activator to activate the GP mix and promote the alkali-activation reactions. The mechanical properties of various GP mixes were analyzed to evaluate the durability of the resulting GP when subjected to firing at temperatures up to 750°C and the destructive effects of gamma-ray irradiation. The study revealed that blending up to 30% granite powder to the GP formulation led to faster setting due to the excess soluble Si ions sourced from the granite powder which accelerated the alkali-activation reactions and increased the stiffness of the pastes. Additionally, blending the GP mix by 10 % GW improved the compression resistance by 7 to 10 % during the later curing ages. Besides, these blended mixes have thermal stability behaviors against firing up to 750°C and irradiation by gamma rays. This is related to the thermal stability and heat storage capability of GW. Amelioration of BFS/GW mix by up to 2% NS greatly improves the compression resistance at all the stages of the alkali-activation process. Furthermore, the mixes reinforced by NS exhibited better durability in the two types of deterioration studied. This is attributed to the thermal stability of GW and the filling and/or catalytic actions of the dispersed nanoparticles through GP matrix. These factors strengthen the geopolymer network, enabling it to withstand the deteriorating effects of these harsh environments. </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> <item> <title>Seismic Performance of 2D Regular Reinforced Concrete Frame Buildings Strengthened by Using Shape Memory Alloys</title> <link>https://www.scientific.net/JERA.72.135</link> <guid>10.4028/p-yc3fXl</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Chayma el Mtili, Loubna Hessissen, Abdellatif Khamlichi Reinforced concrete frame buildings are at risk of earthquake. Improving their response by adequate strengthening provision is an issue of major importance. Among the recent techniques introduced to increase the seismic resistance of this type of structure, shape memory alloy materials were found to be promising. They have large damping properties and significant re-centering capacity that reduce seismic efforts and limit damage. This work was dedicated to assessing the enhancement of building seismic capacity based on shape memory alloys of different sorts. Reinforcement consists of using rebars made from this material to replace longitudinal steel rebars in the critical zones of beams. A comparison of seismic performance induced by this technique with that associated with the conventional option relying entirely on steel as reinforcement was conducted. This was performed in the case of a medium-rise regular building subjected to medium and strong earthquakes when strengthened using four different shape memory materials including nickel titanium and ferrous-based alloys. SeismoStruct software was used to simulate the building through the static pushover analysis and the nonlinear time-history dynamic analysis. The building was anchored in the soil assumed to be rigid and the inelastic displacement-based beam element was used to discretize the structural members by setting up five integration sections and 150 fibers. In comparison with the steel-based option, it was found in both sites of construction that the use of shape memory yields an improvement in seismic resistance and re-centering performance. By using these smart reinforcements, the residual maximum inter-story displacement was reduced to less than a quarter of its value associated with the steel-based reinforcement. Furthermore, ferrous-based shape memory alloys were identified to yield a cost-effective strengthening alternative with regards to the common nickel titanium option and less than 10% of relative variation was observed in comparison with this latter. </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> <item> <title>Longitudinal Profile and Geomorphological Processes of the Oued Qarya in Relation to Lithology and Tectonics (Morocco)</title> <link>https://www.scientific.net/JERA.72.155</link> <guid>10.4028/p-zqr7QP</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Hamid Achiban, Hassan Achiban, Ali Taous, Safaa Serbouti, Ismail Mansouri, Miloud Afenzar Oued Qarya is a left-bank tributary of Oued Zloul (Sebou basin). Its basin drains an area of 323 km2 from the northwestern slope of the Middle Atlas, folded in the province of Sefrou. These are heterogeneous geological terrains of the Lower and Middle Jurassic, dominated by the carbonate rocks of Lias (the mountain of the folded Middle Atlas). In a mountain area with relatively steep slopes, the organization of the hydrographic network and its hydrodynamic functioning are largely influenced by the inclination of the geological formations, the lithology of the terrain, and a dense network of tectonic accidents from the Alpine orogeny, some of which were reactivated during the Quaternary. This study presents the results of the analysis of the morphometry of the main watercourse, the concavity, and the slope breaks of the longitudinal profile of the Oued Qarya. It is essentially based on the determination of their morphometric characteristics, in particular the asymmetry factor (AF), the topographic asymmetry index (TTSI), as well as the concavity indices (IC) and (Er), the slope index (SL), and the index of the slope gradient (k). The results obtained highlight the relationship between the values of these indices and the arrangement of geological formations, the lithology of the terrain, and the influence of tectonics on the longitudinal profiles. The watercourse tends to deviate in the direction of the inclination of the geological formations. In addition, the concavity of the profile is stronger on less resistant geological formations (marl), compared to the sections developed on hard geological formations of limestone and liasic dolomites. In addition, the longitudinal slope of the profiles is generally accentuated on resistant soils, while the passage by ruptures coincides with more or less marked breaks in slopes. </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> <item> <title>A Performance Comparison of the HEC-RAS and TELEMAC-2D Models in Flood Risk Assessment - Application to the Medjerda River</title> <link>https://www.scientific.net/JERA.72.169</link> <guid>10.4028/p-ti9Lit</guid> <description>Publication date: 26 December 2024 Source: International Journal of Engineering Research in Africa Vol. 72 Author(s): Saber Hammami, Hela Romdhane, Amel Soualmia, Azeddine Kourta River flooding is one of the most frequent catastrophic events, with dramatic consequences regarding loss of life and economic damage. For this reason, flood hazard and risk management now appear as the fundamental activities that public bodies and competent authorities must implement to reduce human and socio-economic losses. In this context, this study refers specifically to the flooding at the Boussalem city, crossed by Medjerda river in Tunisia. This work aims to assess the suitability of different numerical tools for reproducing flood dynamics using two different fully two-dimensional (2D) hydrodynamic models, both based on the Saint-Venant equations: TELEMAC-2D and HEC-RAS 6.0. The study compares the accuracy and performance of the two models in estimating flood hazard and risk. Comparative analysis is conducted on flooded area extents from both models for the 2003 flood event and return periods of 20, 50, and 100 years. This is achieved by identifying the roughness coefficient for each land cover type. The comparison encompasses flooded areas for four height classes along the Medjerda River in Tunisia: &lt;0.5m, 0.5-1m, 1-2m, &gt;2m. Details of the analysis of the total flooded area generated by the models show that the percentage difference between the flooded areas decreases as the discharge increases, with differences of 4%, 6%, 16%, and 27% respectively for the 2003 events and the 20, 50, and 100-year return periods. This observation indicates that TELEMAC-2D tends to generate larger estimates of flooded areas as water height increases, suggesting an increased sensitivity to extreme flood events. Conversely, for depth classes of 0.5 to 1 meter and less than 0.5 meters, HEC-RAS produces larger flooded areas than TELEMAC-2D for events with return periods of 50 and 100 years. This divergence can be explained by the influence of specific modeling methodologies of the two software packages. </description> <pubDate>Thu, 26 Dec 2024 00:00:00 +0100</pubDate> <feedDate>Fri, 7 Mar 2025 03:54:35 +0100</feedDate> </item> </channel> </rss>