Welcome to the home page of the Student's Journal of Engineering Africa also written as (SJ Engineering Africa). This is an open-access international journal with both Print (ISSN:3006-5119) and Online (ISSN:3006-5127) Medium. It includes all subjects of Engineering. It is Published by SJC Publishers Company LTD. Our interest is in concepts around Engineering and innovations related to this subject. We ensure that all research projects that have passed the review process are made available online as soon as concerns from the review are addressed. The journal scope covers areas of engineering such as; Biomedical, Software, Civil, Mechanical, Industrial, Electrical, Computer, Chemical, Petroleum, Aerospace, and Architectural. Our publication months are January, April, July, and October each year.
Strength enhancement and self-healing mechanisms in m45 high-strength concrete incorporating bacillus subtilis: an experimental laboratory study.
Background: High-strength concrete (M45) is widely used in structural applications but remains susceptible to microcracking, affecting durability and service life. Bacterial self-healing using Bacillus subtilis offers a potential solution through microbiologically induced calcium carbonate precipitation. Methods: An experimental laboratory study was conducted using M45 concrete with and without bacterial incorporation. Encapsulated Bacillus subtilis with calcium lactate was added to the test group. Compressive, flexural, and split tensile strengths were evaluated at 7, 21, and 28 days. Statistical analysis using one-way ANOVA was performed. Results: Bacterial concrete demonstrated higher strength across all parameters. At 28 days, compressive strength increased from 47.6 MPa to 53.5 MPa (12.4%), flexural strength from 7.2 MPa to 8.1 MPa (12.5%), and split tensile strength from 4.1 MPa to 4.6 MPa (12.2%). All differences were statistically significant (p < 0.05). Conclusion: Incorporation of Bacillus subtilis significantly improved the mechanical properties of M45 concrete through calcite precipitation and matrix densification. Recommendation: Further studies are required to evaluate long-term durability, field performance, and cost optimization for large-scale applications.
Microbiologically Induced Calcite Precipitation
Copyright (c) 2026 Hari Kannan Moorthy, Valarmathi Matheswaran, T. Senthil Kumar M.E Thanapal (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
Primary causes of voltage fluctuations that affect industrial optical sorters. A quasi-experimental study.
Background: The study aimed to identify the primary causes of voltage fluctuations that affect the industrial optical sorter. Methodology: This study adopted a quantitative quasi-experimental design at the ACPCU factory in Uganda to evaluate the impact of voltage fluctuations on a Satake NRM3 optical sorter. Data from a Fluke 435-II analyzer was synchronized with production logs and environmental data over 24 days. The methodology employed FMEA to identify failure modes, alongside Probabilistic Risk Assessment and Monte Carlo simulations to quantify downtime and techno-financial losses, with analysis performed in Excel, MATLAB, and SPSS. Results: Analysis of 241 tagged disturbance events over 24 days reveals that internal operations are the primary drivers of voltage instability at ACPCU Ltd. Load switching (40.2%, n=97) and high-power machinery (32%, n=77) collectively account for 72.2% of all fluctuations, primarily due to large inrush currents and simultaneous motor starts. External factors proved less frequent: surges contributed 14.1% (n=34), while grid instability and heavy rains accounted for 6.7% (n=16) and 5.8% (n=14) respectively. The dominance of internal causes over external grid faults underscores significant local power quality challenges. Specifically, transient dips often coincided with the operation of hullers and aspiration fans. Minimal disruptions were linked to loose wiring (1.2%). These statistics suggest that implementing soft-start mechanisms and staggered motor sequencing could mitigate over 70% of recorded disturbances, significantly stabilizing the 415/240V supply network for the optical sorter. Conclusion: Voltage fluctuations affecting the optical sorter are predominantly caused by internal factory conditions, particularly load switching, loose connections, and phase imbalance. Recommendation: Implement harmonic filtering, load balancing, and routine maintenance to minimize internally generated voltage disturbances.
Copyright (c) 2024 Chriss Atwiine, Venkataramana Guntreddi, Abubaker Abdulkarim, Shuaibu Aliyu Nuhu (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
The use of paper sludge as a self-curing agent in concrete - Experimental laboratory-based comparative study.
Background Self-curing concrete has gained attention due to limitations in conventional curing practices and increasing water scarcity. Internal curing using waste materials offers a sustainable alternative. Paper sludge, a by-product of the pulp and paper industry, has high water absorption capacity and potential as an internal curing agent. Methods An experimental study was conducted using paper sludge as a self-curing agent in M20 grade concrete. Four sludge-to-water ratios (1:7, 1:9, 1:11, and 1:15) were evaluated. Specimens were subjected to two curing conditions: conventional water curing and self-curing. Mechanical properties, including compressive strength, split tensile strength, and flexural strength, were tested at 3, 7, and 28 days as per relevant Indian Standard codes. Results Concrete incorporating paper sludge demonstrated improved performance compared to conventional concrete under self-curing conditions. The 1:15 ratio showed the highest strength, with compressive strength reaching 29.19 N/mm² under normal curing and 23.66 N/mm² under self-curing at 28 days. Split tensile strength and flexural strength also showed similar trends, with maximum values of 5.12 N/mm² and 8.30 N/mm², respectively, under normal curing. Self-cured specimens showed slightly reduced but comparable strength values. Conclusion Paper sludge can effectively function as an internal curing agent, improving strength characteristics and reducing dependency on external curing. Recommendation Utilization of paper sludge in concrete can support sustainable construction practices and waste management. Further studies on durability and long-term performance are recommended.
Copyright (c) 2026 Vignesh Eswaran Sivalingam, Mathialagan Vijayanand, Valarmathi Matheswaran (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
Development of optical fiber Light-Transmitting Concrete (LTC): A narrative review.
Light-transmitting concrete (LTC) containing optical fibers allows natural light to pass through structural elements while maintaining the mechanical characteristics of conventional concrete. This property offers potential applications in energy-efficient buildings, architectural façades, pavements, and infrastructure where daylight utilization is desirable. The present narrative review summarizes published research on optical fiber light-transmitting concrete, focusing on material composition, fabrication methods, optical performance, mechanical properties, durability, and microstructural characteristics. Evidence from previous studies indicates that light transmission in LTC is strongly influenced by fiber parameters such as volume fraction, diameter, and spacing. Increased fiber content generally improves light transmittance, whereas larger fiber diameters and wider spacing tend to reduce transmission efficiency. Mechanical properties, particularly compressive and flexural strength, depend on the interaction between optical fibers and the cement matrix, where weak interfacial bonding and increased porosity may affect structural performance. Durability aspects, including water absorption, permeability, and environmental exposure, remain insufficiently investigated in the existing literature. Although optical fiber LTC demonstrates promising architectural and energy-saving applications, challenges remain in fabrication complexity, cost, and long-term durability. Future research should address fiber–matrix interfacial behavior, standardized testing methods for optical performance, and optimization of fiber parameters to balance structural strength with light transmission efficiency.
Copyright (c) 2026 Muthukumar Manoharan, T. Senthil Kumar M.E. Thanapal, Valarmathi Matheswaran (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
Portable phototherapy hut, a multi- disciplinary approach to neonatal jaundice. An analytical study.
Background: Neonatal jaundice is one of the most common illnesses in newborn infants all over the world. Phototherapy is an effective and widespread treatment for this condition. This project aimed at designing a cost-effective, portable device to treat jaundice in both home and hospital settings. Methodology: This was an analytical study aimed at testing the working prototype after the design process, which is economically and technologically viable in order to develop a portable phototherapy machine. Results: The existing components of phototherapy equipment, conventional phototherapy equipment, LED phototherapy equipment, and fiber-optic phototherapy equipment were reviewed to come up with a cost-effective, portable phototherapy hut. The project used a multi-disciplinary idea model to design a cost-effective and portable device to treat jaundice from both home and hospital. A double-sided illuminating phototherapy device, with a weighted assessment, 18.38(33), was considered. Conclusion: When designing a phototherapy hut, various comparisons were made to choose a solution without any bias, in the weighted criteria assessment, which ranked the best. Recommendation: <!-- [if gte vml 1]><v:line id="Straight_x0020_Connector_x0020_3" o:spid="_x0000_s1026" style='position:absolute; left:0;text-align:left;z-index:251664384;visibility:visible;mso-wrap-style:square; mso-wrap-distance-left:9pt;mso-wrap-distance-top:0;mso-wrap-distance-right:9pt; mso-wrap-distance-bottom:0;mso-position-horizontal:absolute; mso-position-horizontal-relative:text;mso-position-vertical:absolute; mso-position-vertical-relative:text' from="1.2pt,11.2pt" to="464.4pt,11.2pt" o:gfxdata="[binary] " strokecolor="black [3200]" strokeweight=".5pt"> <v:stroke joinstyle="miter"/> </v:line><![endif]--> The use of phototherapy machines should not be limited only to health facilities, but can also be extended for home use.
Copyright (c) 2026 Marvin Mayambala, Jonathan Ocen, Emmanuel Ogwang, Alice Martha Namilo, Emmanuel Omongo (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
A TECHNICAL REPORT ON THE DESIGN AND CONSTRUCTION OF A COMPACT LINEN TROLLEY
In a bid to curb the high infection rates, we have come up with a project to ensure that hospital linen is handled in the appropriate way starting from the transportation, cleaning, ironing, and storage. With proper handling of the linen, there would be low risk of infections to the laundry workers and also a reduced time in supplying the cleaned linen to the different wards. A success in the project would provide a low cost but affordable, reliable and long lasting ways of transporting of infected linen to the laundry department, storing the cleaned linen and distributing them to the different departments using the same medical equipment.
Copyright (c) 2024 PURKWERI JONATHAN ONANG, JIMMY ZAMARA (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
Our design of a Smart dispensing medication trolley will be an affordable lightweight, portable, and easy-to-use dispensing trolley for busy healthcare environments with stainless steel construction making it hard-wearing, long-lasting, and less likely to harbor germs, while the built-in bumper around the base prevents any accidental knocks into walls altering its structure. Additionally, its structure will be assembled with extruded anodized angular walls with a wide worktop made up of different injection molds which will contain diverse coloration and labels corresponding to different drugs’ dosages. Drug packaging of different colors would be designed to be used in conjunction with the differently colored drugs’ molds in order to achieve the right drug issue in drug administration. An additional time-based alarm system with a control element to aid the reset will be in-cooperated in the design to handle the issue of the right time of drug administration. The design will also be incorporated with a patient-to-trolley tagging system as a means of uniquely identifying each patient to his/her dispensing trolley. The design will be integrated with guiding symbols pertaining to each route of drug administration to solve the problem of the right drug route administration. With all these design features, the design documentation will be reserved and revised by authorized project team so that the proposed dispensing trolley can adequately help health workers to adhere to the 5Rs of medication principles, resulting to the reduction in medication errors.
Copyright (c) 2024 Emmanuel Ogwang , Emmanuel Omongo (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
DESIGN OF A LOW-COST PORTABLE WIRELESS ECG DEVICE.
Cardiovascular diseases (CVDs) are a group of disorders of the heart and blood vessels. Some of these include coronary heart disease, cerebral vascular disease, peripheral heart disease, rheumatic heart disease, deep vein thrombosis, and pulmonary embolism. The study aimed to design a prototype of a portable low-cost ECG wireless monitoring device. In the first stage of the simulation, we used the simulation software Proteus to carry out the simulation. The simulation involved adding the Arduino library of proteus into the simulation software as well as adding the heartbeat sensor. In the second stage of the simulation, we used data collected from a 60 beat/minute ECG which required a waveform of 543 samples with 457 samples.
Copyright (c) 2024 Immaculate Asherure , Khalid Alema, Dr. Johnes Obunguloch (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
AN IMPROVED PORTABLE MOUTH GAG ESSENTIAL IN DENTISTRY.
Background Despite World Health Organization’s efforts to promote oral health, there has been lots of failures as the leaving standards per now where sugar consumption, tobacco use and so forth have become a culture increasing the risk of getting the dental caries, gum disease, oral cancer etc. In an interview we made with dentists in Mwesigwa dental clinic, it was revealed that for every patient there is need to keep the mouth open for some time during examination, diagnosis and treatment. With the above mentioned we realized an increasing need for improving visibility of the oral cavity as a requirement during diagnosis because of the need to better dental services. This report is the record of what we did that includes identification of a real life problem and an innovative solution to the problem .This was covered between February and August. Public health needs Covers public health needs and impact which includes an introduction of the need, problem statement, and current solutions to needs, their impacts and gaps, and the project objectives Concept of innovation Conception of the innovation and this includes; introduction of the innovation, product design specification/criteria for success, project idea generation and project idea selection. Engineering analysis Engineering analysis of the proposed solution, its principle and mechanism of operation and the material analysis and simulation of the proposed solution Prototyping and testing covers the budgeting of the selected materials and components, budget justification, prototyping and prospects for the project. Project management Goes to introduce a multi-disciplinary project team and respective responsibilities, project work plan, project management tools, financial management and a summary of meeting minutes for the project
Copyright (c) 2024 Acwe Tracy Aislinga, Ssekamatte Frank, Omongo Emmmanuel, Sumayiyah Natongo (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
DESIGNING AND CONSTRUCTION OF A LOW-COST LABORATORY SLIDE DRYER.
Our project is about the design and construction of a low-cost laboratory slide as an immediate means to mitigate the problems associated with the delay in the drying of blood slides during the diagnosis of malaria in various local clinical laboratories, the team focused on designing a portable low-cost slide dryer which operates in a way that when the blood slides are inserted inside it, the optimum time taken to dry the blood slides is minimized making the task effective and effective. The recent pandemic and endemic (COVID 19 and EBOLA) respectively have profoundly impacted global malaria elimination programs resulting in a sharp increase in malaria morbidity and mortality. To reduce this impact, unmet needs in malaria diagnostics must be addressed while resuming malaria elimination activities. Rapid diagnosis tests (RDTs), the unsung hero in malaria diagnosis, work to eliminate the prevalence of plasmodium falciparum malaria (species) through their efficient, cost effective and user-friendly qualities in detecting the antigen hrp2 (histidine _rich protein 2), among other proteins, however, the testing mechanism and management of malaria with RDTs presents a variety of limitations that is to say identifying of certain malaria parasites in blood. When carrying out serological surveys, particularly in remote locations, it is of great advantage to have a method of collecting and storing blood samples which does not require that facilities for centrifugation and which is relatively robust to irregular degrees of refrigeration, at least for short periods.
Copyright (c) 2024 Patrick Angwe, Jalia Namutebi, Emmanuel Ogwang (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
A TECHNICAL REPORT ON THE DESIGN AND CONSTRUCTION OF A SMART WASTE BIN FOR MEDICAL WASTE MANAGEMENT
Our project is about the design and construction of a smart waste storage device as an immediate means to mitigate the problems associated with poor Medical waste management through sterilization. Medical waste is waste generated during the diagnosis, treatment, and immunization of human beings or waste generated by healthcare establishments, research facilities, and laboratories. These medical wastes are categorized by level of infectiousness and their effects on human beings and the environment. For example, non-infectious waste is usually put in black disposal bins), infectious waste is usually put in yellow disposal bags or bins and highly infectious waste is usually disposed in red bins. The highly infectious wastes pose a greater degree of infection to persons who come into direct contact with such wastes. This infection can be bacterial, fungal, and viral infections, infections resulting from chemical spills and radioactive substances. Depending on the volume and the type of medical waste generated, hospitals have several options when it comes to waste disposal. On-site as well as off-site options are available to some but before medical waste can be transported off the property of a medical waste generator, some of it must be properly treated to reduce or eliminate the infectious potential of that waste before it hits the road to its disposal location. The pre-treatment not only reduces the volume of internal medical waste heading to landfills (as non-infectious or decontaminated waste) but also ensures a reduction or complete removal of potentially infectious materials found in the variety of the medical waste streams produced by the hospital. Two primary options applicable for pre-treatment or destruction of wastes for the hospital are incineration or autoclaving. However, the effectiveness of medical waste management using the available primary options in every health facility depends majorly on the awareness of the health personnel, waste management team, and the general fraternity of the hospital including the patients, availability of personal protective gear, internal and external regulatory framework, and financing organ. In our project, the team focused on designing an automatic waste storage device. It operates in a way that when a person is within the set distance, a sensor outside the waste bin detects him/her and the lid opens automatically with the help of a motor that functions on the principle of servo mechanism.
Copyright (c) 2024 Okethwengu Herbert, Amisiri Belinda, Emmanuel Ogwang (Author) https://creativecommons.org/licenses/by-nc-nd/4.0
UV STERILIZATION DEVICE FOR PERSONAL ITEM-RELATED INFECTION CONTROL DURING MEDICAL PRACTICE IN HEALTH FACILITIES.
Multidisciplinary design is one of the requirements for the award of a National Diploma in Biomedical Engineering considered with great importance by UBTEB to produce future employees who are competent enough to work for the betterment of Uganda’s Health. As such students are required to design any medical equipment about the needs in the health environment. This report is the record of what we did that includes identification of a real-life problem and an innovative solution to the problem. This was covered between August and November 2022. The report consists of three chapters that altogether explain the public health need and impact, conception of the innovation, and project management. This entails identification of the need from the source, definition of the problem and the objectives of the project, product design specifications, various design alternatives and justification of the selected design alternatives, project work plan, and conclusion. Public health need and impact which includes an introduction of the need, problem statement, and current solutions to needs, their impacts and gaps, and the project objectives. Conception of the innovation and this includes; introduction of the innovation, product design specification/criteria for success, project idea generation, and project idea selection. Introductions of engineering analysis of the proposed solution, its principle and mechanism of operation, and the material analysis and simulation of the proposed solution.
Copyright (c) 2024 Emmanuel Ogwang , Gerald Job Alamiga , Michael Ssebuyira (Author) https://creativecommons.org/licenses/by-nc-nd/4.0