East African Journal of Engineering

Distribution of Floods Frequency of Manafwa River, Uganda

Joseph Micheal Okoth, Daniel Otim, PhD, Edwin Kamalha, PhD — Wed, 24 Jan 2024 09:09:51 +0000

The objective of this study was to analyse Manafwa River flood frequency in Eastern Uganda. Analysis of Manafwa River maximum annual flows from 1949-2015 was undertaken using Log Pearson 3 distribution in comparison with Gumbel, Normal and Log Normal distributions to determine frequency of occurrence and magnitude of extreme floods. Statistical analysis including goodness of fit tests of chi-square, Kolmogorov-Smirnov and Anderson-Darling tests were used to generate the most suitable probability distribution model. The results show quantile magnitudes lowest for Log Normal distribution at 43.59 m3/s and highest for Log Pearson 3 distribution at 51.67 m3/s. The 5-year quantile estimates are highest for Normal and Log Pearson at 70.37 m3/s and 63.99 m3/s respectively. The 10-year quantile estimates are highest for Log Normal and lowest for Log Pearson 3 distributions at 87.57 m3/s and 75.13 m3/s respectively. The 100-year quantile estimates are lowest for Normal and highest for Log Normal distributions at 108.57 m3/s and 154.66 m3/s respectively. The 200-year quantile estimates are lowest for Normal and highest for Log Normal distributions respectively at 114.980 m3/s and 177.16 m3/s respectively. Log Pearson 3 distribution emerged as best fit for data. From the statistical analysis, LP 3 probability distribution presents the most accurate regression coefficient at 0.8486 and the most suitable distribution of goodness of best fit using A-D, K-S and Chi square tests followed by the Gumbel distribution. The tests yield 0.15666, 0.04855 and 0.88502 for A-D, K-S and Chi square tests respectively for the LP 3 distribution. There is an increasing upward trend of the discharges at Manafwa River floodplains at higher probabilities of exceedance across all the probability distributions due to varrying climatic changes and rapid landuse changes in the Manafwa catchment. Manafwa river floodplains have the capacity to accommodate and boost crop production and productivity. Any nutrients lost to leaching could be gained from subsequent fallowing and sustainable soil fertility management including; proper drainage, crop rotation, adding organic manure, cover cropping and among others

Analysing Bevel Gears for Efficient Power Transmission: A Study on Design, Simulation and Performance Assessment

Mon, 05 Feb 2024 10:50:24 +0000

Bevel gears find application in transmitting motion between unequally aligned shafts, typically forming a 90° angle relative to each other. Some of the several types that are available commercially are the straight bevel, the Zerol bevel, the spiral bevel, and the hypoid. Stainless steel, gray cast iron, titanium alloy and structural steel were used for the behavioural assessment. The design and modelling of the straight bevel gears were carried out using SolidWorks 2015, while ANSYS 18.2 was employed simulating to simulate the gears' stress and deformation. The 3D solid model generated using SolidWorks was imported into ANSYS, where the analysis was conducted using the finite element software, ANSYS Workbench. Stress distribution plot, deformation plot, and equivalent strain plot were generated. The highest stress, measuring 73.536 MPa, became evident as the load concentrated near the base of the gear teeth. The finite element analysis revealed a minimal likelihood of gear failure, and the least deformation was observed in the structural steel configuration, resulting in a deformation of 8.2354 x 10^-3 mm. Consequently, the gear pair can successfully transmit 6 kW of power without experiencing any failures with a good safety factor

Level of Awareness on the Usage of Thermal Insulation among Building Professionals: Case of a Tropical City in Nigeria

Morisade Omorinola Adegbie, Yususf Olatunji Hammed — Mon, 11 Mar 2024 14:30:44 +0000

Adoption of buildings’ thermal insulation in Nigeria is still at the developmental stage; evidence of its usage for high thermal performance buildings and energy efficiency connotes a very low rate as there is very little evidence-based research in this regard. This paper seeks to evaluate the level of awareness on the usage of building thermal insulation among professionals in the building construction sector within Akure, a tropical city in Nigeria, to identify factors that deter its adoption and raise the level of commitment of the professionals within the building construction sector to sustainable practices of reducing buildings’ energy consumption. This is to create a resilient built environment against the challenges of climate change. Well-structured questionnaires were administered to gather data for the investigation. Jupyter Notebook version 6.4.12 was employed for the analysis. Results indicated a fairly good level of awareness among the building professionals while the barriers that affect the level of usage of thermal insulation within the study area are the high cost of procuring thermal insulation materials, non-compliance to building regulations, and governmental policy on construction. The research concluded that a good number of professionals have a high level of awareness of the usage of building thermal insulation, but the cost of the materials and government policy deterred its level of usage in the study area. Consequently, propagation of the usage of thermal insulation should be done through education and training of the stakeholders. Furthermore, the government needs to strengthen policies that support the usage and availability of thermal insulation within the study area

Development of Solar PV Assisted Dryer for Cooking Banana Slice and Analysis of Proximate Properties

Promise Joseph Etim, Uwemedimo E. Udo, Inemesit E. Ekop, Ekom E. Okpo — Mon, 15 Apr 2024 16:30:03 +0000

A solar PV-assisted dryer was developed for drying cooking banana and its performance tested. The proximate properties of the products dried in the solar PV-assisted dryer were compared to similar products dried using a laboratory oven, while open sun drying served as the control experiment. Fresh samples of cooking banana were obtained from a rural market in Ikot Akpaden, Mkpat Enin, Akwa Ibom State, Nigeria. The samples were subjected to peeling and cleaning before being sliced to a thickness of 5 mm. The dryer was embedded with a DC blower to enhance air circulation in the drying chamber. The blower was powered by a solar panel connected to a DC battery and a charge controller. 500 g of the product was loaded in the solar PV-assisted dryer, same as the other mediums. The moisture content was observed to have reduced from 67.32 to 5.80 % within 6 hours of drying as against 13 hours of open sun drying. The drying rate of the product decreased from 0.092 to 0.028 kg/hr in the solar PV-assisted dryer. The efficiency of the dryer was 40.6 %. Crude protein, crude lipid, crude fibre, and caloric value were lower in samples dried using the solar PV-assisted dryer and higher in samples subjected to drying in the laboratory oven and the control experiment. Ash content and carbohydrates were higher in products dried using the solar PV-assisted dryer than in other mediums. The study adds significant knowledge to the development of systems for post-harvest processing of cooking banana, a product highly sought for in the local market as a viable alternative to banana and plantain

Characterizing River Manafwa Floodplain and Adjacent Soils

Joseph Micheal Okoth, Daniel Otim, PhD, Edwin Kamalha, PhD — Tue, 23 Apr 2024 17:05:56 +0000

The objective of this study was to characterise Manafwa River floodplain and adjacent soils. Soil samples were collected from 0 - 20 cm depth in fallowed and cultivated Manafwa floodplain soils for laboratory analysis. Treatments included upland (control), floodplains fallowed for a year, floodplains fallowed for over a year, cultivated floodplains within 5 m and 50 m away from the river banks. Each treatment was replicated three times (3 blocks), and samples collected were analysed for K, Na, available P, total N, exchangeable acidity, pH, organic matter, moisture content, sand, silt, and clay. The soil sampling results were subjected to statistical Analysis of Variance (ANOVA) using Randomised Complete Block Design (RCBD), and the difference between treatment means were dictated using F-, student’s t and F-LSD/pairwise comparison tests. There was statistically no significant (p > 0.05) difference among different floodplains and uplands studied. Upland soils posted 71.67% for the highest pH and 0.09%, 0.87%, 9.74 ppm, 2.23 ppm and 7.264% for the lowest available N, organic matter, Phosphorous, Sodium and Moisture Content, respectively. Cultivated floodplain soil posted highest total P at 29.16 ppm and pH at 6.39% while fallowed floodplains lowest pH at 5.34%, highest available N at 0.32%, highest organic matter at 4.02%, highest K at 21.33%, highest Na at 13.93%, highest exchangeable acidity at 2.32 Cmol/Kg, highest clay content at 14.33%, lowest sand composition at 38.00%, highest silt composition at 54.8% and highest Moisture Content of 32.472%. As depicted by soil fertility analysis results, Manafwa River floodplain and adjacent soils have the capacity to accommodate and boost crop production and productivity. Any nutrients lost to leaching could be gained from subsequent fallowing and sustainable soil fertility management, proper drainage, crop rotation, adding organic manure, and cover cropping, among others

Addressing Differential Axial Deformation Effect and Sway in 3D Building Frame Analysis

Tukashaba Shafan — Wed, 01 May 2024 08:57:52 +0000

The Differential Axial Deformation Effect (DADE) is a significant consideration in the 3D analysis of building frames, where elements like columns and walls experience compression forces leading to differential shortening. Traditional design methods often overlook DADE, yet the existing building stock seems serviceable despite this omission. However, modern 3D analysis inherently introduces DADE, prompting designers to seek methods to approximate traditional design forces while utilizing advanced analysis techniques. The aim is to achieve design forces close to those historically used, ensuring structural integrity without disregarding DADE entirely. The methods outlined in this report demonstrate how to reconcile 3D analysis results with traditional design principles while also addressing concerns about sway deflections and the need for a conservative approach. While there's a debate about the economic viability of designing for a wider envelope of design conditions, the report illustrates that the additional reinforcement needed is typically minimal. Notably, the DADE phenomenon is universal across Finite Element Method (FEM) analysis software, and the strategies discussed here can be applied across different platforms. The notion that staged construction analysis effortlessly resolves DADE issues is debunked. Staged construction analysis is complex, doesn't fully eliminate DADE, and can yield unreliable results if not used carefully. In summary, this report offers practical insights into navigating DADE in 3D structural analysis, emphasizing the importance of balancing modern techniques with traditional design considerations

Assessing the Environmental Sustainability of UHPC in Modern Construction Practices

Tukashaba Shafan — Sun, 12 May 2024 17:28:16 +0000

A comprehensive examination was undertaken to investigate various aspects related to the development and application of Ultra-High-Performance Concrete (UHPC). The research explored eco-friendly approaches, such as incorporating supplementary cementitious materials and nanoparticles, optimizing binder systems, and assessing chemical activators. These modifications improved mechanical properties and reduced environmental impact, including embodied CO2 emissions. Additionally, the utilization of waste materials like CRT glass showed energy savings and reduced emissions. Studies focused on optimizing UHPC mix designs, emphasizing a balance between performance and environmental impact. Techniques like statistical mixture design methods and dynamic testing assessed UHPC's environmental and economic impacts, highlighting significant energy savings and reduced CO2 emissions with waste material recycling. Overall, the research contributes valuable insights into UHPC development and its ecological footprint in construction

Strategic Transportation Planning: Soft Mobility Network Planning Technical Report

Tukashaba Shafan, Shingiro Clement — Tue, 21 May 2024 00:00:00 +0000

This technical report presents a comprehensive approach to soft mobility network planning, focusing on assessing the potential for growth in bicycle infrastructure. Utilizing GIS-based analysis and multi-criteria decision-making, the study aims to identify and prioritize areas for new bike infrastructure development. The methodology involved defining influential factors, selecting variables from available datasets, assigning value levels, weighting parameters, and generating cycling infrastructure potential maps. Factors such as connectivity, safety, and attractiveness are considered, with each variable assessed and scored based on current conditions and ideal benchmarks. The results highlight high-potential areas for infrastructure improvement and propose desired lines to enhance the existing network. Limitations of the study, including data currency and grid dimensions, are acknowledged, suggesting avenues for future research and improvement. Overall, the study underscores the importance of integrated planning approaches and the utilization of spatial analysis tools in promoting cycling as a sustainable and accessible mode of transportation

Petroleum Potential Prospectivity of Muglad Basin, South Sudan: A Case of Source Rocks Characterisation in the Drilled Kaikang West-1 Well

Panom Bol Juach, Simiyu Wanjala Joseph, Gatluok Koang Gach, Bernard Kipsang Rop — Tue, 21 May 2024 09:55:09 +0000

This study focuses on Prospectivity of Petroleum Potential of Muglad basin, South Sudan, with the help of petroleum source rocks characterisation in the drilled Kaikang West-1 Well based on the organic matter quantity, quality, and the thermal maturation generation capability of the organic matter disseminated in the analysed rock samples. Muglad basin is a major petroliferous Western and Central African Rifts System (WCARS) member, with estimated reserves of 2,053 mm bbl. Muglad Basin comprises thick sandstones of Aradeiba and Bentiu Formations, considered to be the main petroleum prospectivity targets, with trapping mechanism being structural faults and lithological anticlines. The organic matter contents were determined directly from laboratory analyses of the source rock samples with the help of seismic and gamma ray profiles, total organic carbon (TOC wt %), maturity indices (OI, HI and PI), temperature maximum (Tmax °C), porosities and other sedimentological parameters. This study involved a series of analytical geochemistry and petro-physical studies to ascertain a number of effective source rock samples from the Well cores which were then analysed in terms of TOC, OI, PI, HI, S2, S1 and Tmax to determine oil/gas prone samples (resource areas). These were then distinguished from strata with very high organic matter samples as well as very high TOC to help identify for possible source rock characterizations within the lithology pertaining to the Well in terms of potential source-reservoir-seals combinations. The Rock-Eval pyrolysis data were useful in assessing and evaluating the type of organic matter, thermal maturity, and the generation capability of source rocks for hydrocarbon exploration rationale. The analyses revealed that some strata, within the sampled Well data, have high hydrocarbon generation potential with the existence of commercial hydrocarbon production

Strategic Transportation Planning: Co-Site Planning at Coolwood SA Company

Tukashaba Shafan, Shingiro Clement — Thu, 23 May 2024 09:28:08 +0000

This technical report presents a meticulous exploration of the site planning endeavours undertaken by CoolWood SA, a distinguished entity in wood furniture production, as it endeavours to relocate its operations to Hasselt, Belgium. With over 15 years of industry expertise, CoolWood SA seeks to optimize spatial utilization and operational efficiency through strategic site planning. The report delves into the intricacies of site location, area adjustment, department allocation, external flow access to the warehouse, and current road infrastructure analysis. Utilizing a multifaceted approach, CoolWood SA collaborated with Afro International Transport Planning Consultants to employ various software tools and adhere to international standards throughout the planning process. Key findings include detailed area adjustments, department allocations aimed at enhancing operational efficiency, and analyses of internal circulation, parking requirements, and external traffic movement. Notable measures such as prioritizing employee safety, accommodating diverse transportation modes, and promoting cleanliness and hygiene within the facility are meticulously outlined. The report concludes with insights gleaned from sight distance analyses, swept analysis simulations, and overarching recommendations for CoolWood SA to elevate safety standards and facilitate industry growth. By implementing the proposed strategies and measures, CoolWood SA stands poised to navigate its relocation journey with precision and foresight

Analytical Design of a Portable Surface Plasmon Resonance Sensor by Using a Divergence Beam for Measuring Multiple Heavy Metals and Other Contamination Simultaneously

Jordan H. Hossea, Georgia Rugumira — Tue, 04 Jun 2024 14:26:33 +0000

The study proposes a surface plasmon resonance (SPR) sensor for measuring water quality by detecting the presence of heavy metal ions and other contamination. The proposed SPR sensor operates in the Kretschmann configuration, which employs the divergence beam produced by the Powell lens. The beam is diverged to eliminate mechanical scanning, indicating that the sensor can measure water quality from deionized water (DIW) with refractive index (RI) of 1.3317, diluted DIW with multiple heavy metal ion such as Hg[II], Pb[II], Ni[II], Zn[II], Cu[II] at concentration of 100 μM and other pollutant with the RI of 1.34 without any mechanical movement. The proposed SPR sensor has a theoretical sensitivity of 399.45˚/RIU and resolution of 1.3456×10-8 and 8.3790×10-10RIU with 8-bits (ATmega1284) and 12-bits (STM32F401RE) ADC of the controller, respectively. The CCD sensor (TCD1304AP) and microcontroller data sheets were used to calculate the theoretical in which all these components are very chip. The reported sensitivity and resolution were achieved because of the proper application and optimization of TiO2 and BaTiO3. In comparison to a conventional SPR sensor, the proposed SPR improved sensitivity and figure of merits by 50.98 % and 13.93 %, respectively. Furthermore, the proposed SPR sensor outperforms recently published research in terms of performance

Project Staff Scheduling and Performance of Road Construction Projects in Nairobi Metropolitan, Kenya

Simon Karuga, Paul Sang, Morrisson Mutuku — Thu, 13 Jun 2024 07:28:18 +0000

The performance of a road-building project is frequently measured on the basis of quality, timeliness, and cost. Various road-building projects around the world struggle to satisfy these performance standards. Road projects are intended to adjust to changing weather, site, economic resources, community, and physical variables during construction. To that end, the purpose of this research was to analyse the relationship between project staff scheduling and the performance of road construction projects in Nairobi Metropolitan, Kenya. The research was based on ability, motivation, and opportunity theory. The study adopted a positivism research philosophy to empirically quantify facts through statistical analysis. A descriptive design as well as a cross-sectional survey was used. The population of interest for this study consisted of 39 road construction projects being implemented by Kenya Urban Roads Authority and Kenya National Highway Authority within the Nairobi metropolitan area. The study focused on county and national government roads. As a result, 195 participants were selected for this study. To gather primary data, a semi-structured questionnaire was used. Descriptive and inferential statistics were used to analyse the quantitative data. For inferential statistics, multivariate regression analysis and correlation were used. The study's findings showed that the scheduling of project staff significantly and positively (β =0.806, p =0.000) influenced project performance. According to the study's findings, staff scheduling, when done correctly and in accordance with work requirements, allows employees to stay on task and know exactly what they are supposed to be doing every day. Project managers can more quickly and easily locate coverage for sick days or vacations thanks to staff scheduling. Avoiding the need to hire more employees for a brief duration, enables the company to save money. Employee flexibility in managing work obligations and timely task completion is ensured by staff scheduling, which improves project performance

Effectiveness of Speed Cameras on the Prevention of Road Traffic Collisions and Casualties in Cameroon

Apongnwu W. Awamachi, Mbu D. Tambi, Nkeng G. Elambo — Thu, 13 Jun 2024 17:55:37 +0000

Issues related to transport collision and casualties cannot be undermined as it has a direct effect on human health and death, hence relevant policies are required to reduce road traffic accidents. Our study discussed the factors influencing the use of speed cameras by drivers in Cameroon, the study investigated the effects of speed cameras on the prevention of road traffic collisions and casualties in Cameroon and determined the actual problems faced by drivers in the use of speed cameras in Cameroon. Methodologically, the study applied the probit technique to estimate the result via primary data. The sample size consisted of 200 drivers collected through a well-structured questionnaire distributed among the drivers plying the Yaoundé-Douala, Douala-Bafoussam, and Bafoussam-Yaoundé major highways. The key findings revealed a significant link between the factors influencing drivers' use of speed cameras and their impact on road safety. These factors included main occupation, level of education, marital status, age, and prior involvement in traffic incidents. Notably, the study found that an increased presence of speed cameras led to a substantial reduction in road traffic collisions by 41.4% and road traffic casualties by 6.9%. This emphasized the crucial role of speed cameras in effectively mitigating road accidents and their resulting injuries in Cameroon. Alongside this, it highlighted the practical challenges associated with speed camera implementation, such as inadequate awareness, abrupt speed changes, signage issues, limited visibility, technical constraints, and privacy concerns. These findings collectively underscored the need for comprehensive strategies to address both the behavioural and infrastructural aspects of road safety to ensure the effective use of speed cameras for accident prevention in Cameroon. The study suggests that decision-makers in the transport sector should multiply the provision of speed cameras. This is a wise step in the prevention of road traffic collisions and casualties in Cameroon and a better labour market

Comparative Analysis of Performance of Mat Foundations in Non-liquefiable and Liquefiable Soil

Tukashaba Shafan, Ping Yi — Thu, 13 Jun 2024 00:00:00 +0000

This study investigates the behaviour and performance of mat foundations in non-liquefiable and liquefiable soil, aiming to provide insights for engineers under soil liquefaction conditions. Through finite element analyses, the study explores shallow foundation design complexities, assesses the bearing capacities of mat foundations under liquefaction soil characteristics, and offers data-driven design strategies for such conditions. The findings on mat foundations in liquefiable soil reveal that iterative dimension adjustments lead to significant enhancements in bearing capacity, hence exceeding the load-bearing capacity in non-liquefiable soil that is used as benchmark. The modification factors range from 2.4 to 2.6 times the original dimensions verified to be effective. These results emphasize the role of tailored design adjustments and numerical designs in solving diverse soil settings and enhancing structural safety, performance, and integrity in foundation design, especially in challenging soil conditions with liquefaction