Department of Physics and Computer Science
Permanent URI for this collectionhttps://dspace.njala.edu.sl/handle/20.500.144402/139
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Item Promoting Sustainable Development through Waste Recycling: A Case Study of Green Entrepreneurship in Bo City, Sierra Leone(International Journal of Innovative Science and Research Technology, 2025-05-05) Bangura, HelenThis particular project indeed concentrates on the evaluation of the role of green entrepreneurship towards enhancing sustainable development through waste recycling processes within Bo Town, Sierra Leone. The research investigates the green entrepreneurial activities via 384 participants' responses from survey collections in combination with focus groups and face-to-face interviews. Environmental sustainability promotion through youth advocacy mainly occurs amongst people aged from 18 to 34 with equal participation rates across males and females. Waste recycling operations run by local entrepreneurs manifest significant footprints of impact through plastic recycling activities at 40 percent and organic composting at 25 percent. This, along with the community-based efforts, reflects the growing commitment to addressing waste management issues in the area. Positive impacts from green entrepreneurship include job and awareness creation, as well as cleaning the locality, but the challenges still exist. The path of progress faces insurmountable hurdles due to three major constraints, which are limited government support (38%), poor waste collection management (30%), and barriers to market entry of recycled materials (12%). The results could be proved as 65% of people observed a remarkable drop in the extent of waste in and around their neighborhoods and the level of contamination. Sustained improvement requires stringent government policies as well as an efficient public awareness strategy and infrastructure. The movement can also best progress by developing education courses for entrepreneurs and a reliable market for recycled materials. Future studies should analyze the poverty reduction impacts of green entrepreneurship and compare the barriers in urban and rural areas while considering extensive environmental impacts. The research is likely to investigate its efficacy against climate change. Green entrepreneurship ensures that Bo Town and wider communities have a sustainable future potential.Item DeepEVD: Integrating Epidemiological data into deep learning frameworks based on spatio-temporal feature learning for EVD forecasting(Elsevier BV, 2025-08-01) Fofanah, Abdul JosephThe paper introduces DeepEVD, an innovative framework that integrates human mobility data to forecast Ebola Virus Disease (EVD) outbreaks. Traditional epidemiological models often struggle to account for the dynamic nature of human movement, which is crucial for understanding EVD transmission. DeepEVD leverages diverse mobility data sources, including phone records, GPS traces, and social media posts, to extract significant spatio-temporal features. It utilises Graph Convolutional Networks (GCN) and Long Short Term Memory (LSTM) networks to establish connections between mobility patterns and EVD cases across both space and time. The framework was tested on real-world datasets from the 2014-2016 West Africa outbreak and the 2015-2016 Sierra Leone outbreak, demonstrating a 5%-10% reduction in forecasting errors compared to baseline methods. Ablation studies reveal the impact of various data sources and feature extraction methods on accuracy. DeepEVD not only delivers state-of-the-art performance, but it also provides actionable insights for EVD prevention and control. Implementation of the proposed DeepEVD can be accessed here https://github.com/afofanah/DeepEVDMob.Item Baseline Assessment of Ambient Total Volatile Organic Compounds in Urban Streets of Freetown, Sierra Leone(Science Publishing Group, 2025-08-05) Abu, Mohamed**Background:** This study addresses the critical issue of air pollution and its implications for public health, especially in rapidly urbanizing regions such as Freetown, Sierra Leone. Total volatile organic compounds (TVOC) are significant pollutants that play a crucial role in the formation of ground-level ozone and are associated with various adverse health effects. **Objective:** The primary objective of this research was to conduct the first comprehensive assessment of ambient TVOC levels within the urban streets of Freetown. **Methods:** Measurements were carried out over a four-week period on fourteen major streets using calibrated DM502 air quality monitors, held approximately 2 meters above ground to simulate breathing zone conditions. The collected concentration data were subsequently extrapolated to estimate 24-hour average levels, providing a more accurate depiction of typical exposure. Additionally, toxicity potentials (TP) were calculated for each sampling location to evaluate potential health risks. **Results:** The findings revealed that the average extrapolated 24-hour TVOC concentrations across the sampled streets ranged from 0.06 and 0.18 mg/m3, with the highest average at Pademba Road (FS3). Overall, the average TVOC level across all streets was 0.08 mg/m³, which is below the World Health Organization’s (WHO) guideline limit of 0.3 mg/m³. The maximum toxicity potential observed was 0.59 at FS3, with an overall average TP of 0.26, indicating moderate potential health risks. Weak correlations were observed between TVOC concentrations and environmental parameters such as temperature (R² ≈ 0.16) and relative humidity (R² ≈ 0.0025), suggesting that other factors might influence VOC levels. **Conclusion:** Despite the current levels are within safety standards, continuous monitoring is recommended due to the possible health implications of long-term exposure. This research provides vital baseline data essential for urban air quality management and policy development in Sierra Leone.Item Assessment of the Strengths, Weaknesses, and Gap-Fix Needs of Healthcare Infrastructure in Sierra Leone(Scholar Publishing, 2025-07-25) Kamara, Yahya LabayHealthcare in Sierra Leone has faced significant challenges due to historical instability, economic constraints, and disease outbreaks such as the Ebola epidemic. Despite policy reforms like the Free Healthcare Initiative (FHCI) and post-Ebola recovery efforts, systemic weaknesses persist in infrastructure, workforce capacity, and financing, hindering progress toward Universal Health Coverage (UHC). This study assesses the strengths and weaknesses of healthcare infrastructure in Sierra Leone, evaluates the impacts of key interventions, and proposes sustainable strategies for improvement. A mixed-methods approach was used, combining quantitative data analysis from national and international health reports, a systematic literature review (following PRISMA guidelines), and comparative policy analysis. Data sources included the Sierra Leone Ministry of Health, World Health Organization, World Bank, and peer-reviewed studies. The key strengths of healthcare system in Sierra Leone include the success of the FHCI in improving maternal and child health outcomes and the role of community health workers (CHWs) in expanding rural healthcare access. However, critical weaknesses persist, such as severe workforce shortages (0.2 doctors per 10,000 people), inadequate infrastructure (40% of healthcare facilities lack reliable electricity), and heavy reliance on volatile donor funding (60% of health expenditures). Urban-rural disparities remain high, with rural areas experiencing higher maternal mortality and lower vaccination coverage. To strengthen healthcare infrastructure, Sierra Leone must expand medical training, incentivize rural workforce retention, invest in infrastructure through public-private partnerships, and increase domestic health financing. Leveraging technology (e.g., telemedicine) and decentralizing services are also vital. Sustainable progress requires multi-sectoral collaboration, government commitment, and international support to achieve equitable and resilient healthcare delivery.Item Assessment of Background Noise Levels in Four Commercial Areas of Freetown, Sierra Leone(2025-06-04) Abu, Mohamed MustaphaEnvironmental noise is a significant public health issue, particularly in rapidly urbanizing cities where commercial activities contribute to elevated noise pollution. Despite its numerous implications, few studies have focused on noise levels in commercial environments in developing countries. This study aims to fill this existing gap by assessing background noise levels in four commercial areas of Freetown, Sierra Leone: Aberdeen Market, Godrich Street, Jui Junction, and Sani Abacha Street. Using a calibrated handheld sound level meter, measurements were taken during daytime, evening, and nighttime periods over one week. Noise levels were analyzed using the day-evening-night equivalent continuous noise level (Lden) and statistical methods to assess compliance with World Health Organization (WHO) guidelines. Results revealed that all areas exhibit average noise levels above the WHO recommended limit of 70 dBA during daytime and evening hours, with Godrich Street and Aberdeen Market exhibiting the highest average daytime noise level (95.35 dBA) and the lowest average nighttime noise level (53.05 dBA) respectively. Godrich Street recorded the highest Lden value and shortest allowed exposure of 93.34 dBA and 1.17 hours respectively, indicating the most significant risk of prolonged exposure. Recommendations include creating designated quiet zones tailored to local commercial layouts, stricter enforcement of noise regulations, public awareness campaigns on hearing protection, and regular noise monitoring to guide urban planning. This study provides crucial insights for mitigating noise pollution and improving urban sustainability in developing nations.Item An Integrated PMT-TAM Approach to Cybersecurity Awareness: Evidence from Sierra Leone's Universities and Policy Lessons for Developing Nations(2025-08-27) Koroma, MohamedThis study pioneers the first empirical integration of Protection Motivation Theory (PMT) and Technology Acceptance Model (TAM) in West African academia to analyze cybersecurity awareness among 1,000 students across 10 Sierra Leonean universities (5 government, 5 private) using PLS-SEM. The novel PMT-TAM framework addresses theoretical fragmentation in behavioral cybersecurity literature by demonstrating how institutional factors (TAM) compensate for cognitive limitations (PMT) in resource-constrained settings a dynamic previously unexplored in African contexts. Results reveal moderate overall awareness (M = 3.42/5) but critical gaps, with only 12% accurately identifying phishing attempts. Key findings show self-efficacy (β = 0.58) and institutional support (β = 0.49) as the strongest predictors of protective actions, while perceived severity had weaker impact (β = 0.35). A significant "usage-awareness gap" emerged, with 89% of students using the internet daily but lacking fundamental security knowledge. Private institutions outperformed government counterparts in training quality (4.12 vs. 3.56, p < 0.01) and tool adoption (68% vs. 41% VPN usage). Theoretically, the findings advance hybrid behavioral models by revealing context-specific mediation effects (63% of perceived severity’s impact mediated by self-efficacy). Practically, the study provides actionable policy benchmarks, including allocating 3% of university IT budgets to cybersecurity and establishing national training standards. These insights are critical for developing nations undergoing rapid digitalization with limited security education infrastructure.Item Airborne Particulate Matter Concentrations at Key Transportation Stations in Freetown, Sierra Leone: Compliance With WHO Guidelines(2025-05-30) Abu, Mohamed MustaphaAir pollution, particularly from particulate matter (PM), is a significant public health risk, especially in urban environments where transportation plays a critical role. This study quantifies airborne particulate matter (PM1.0, PM2.5, and PM10) concentrations at key transportation stations (Central and Shell Bus Stations) in Freetown, Sierra Leone. Multifunctional digital air quality monitors (DM502) were used to record measurements during the rainy season in August and at peak traffic hours, spanning three daily intervals: 7:00–11:00 AM, 12:00–4:00 PM, and 5:00–9:00 PM. Our findings reveal elevated levels of particulate matter throughout the study. The average concentrations at the Central Bus Station of 15.40 µg/m³, 27.60 µg/m³, and 31.38 µg/m³ for PM1.0, PM2.5, and PM10, respectively. At Shell Bus Station, these values were notably higher, with averages of 17.71 µg/m³ for PM1.0, 30.33 µg/m³ for PM2.5, and 37.24 µg/m³ for PM10. These average concentrations notably exceed the World Health Organization (WHO) 24-hour guidelines of 15 µg/m³ for PM2.5 and 45 µg/m³ for PM10, indicating deteriorating air quality in these densely populated transit areas. Also, the mean Air Quality Indices (AQI) of PM2.5, and PM10 at Central Bus Station are 95.16 and 26.81 respectively while mean AQI of PM2.5, and PM10 at Shell Bus Station are 90.05 and 32.08 respectively. Significant variations were observed throughout the week, primarily influenced by daily traffic patterns and local activities. Peak PM2.5 levels reached 62.33 µg/m³ at Central Bus Station and 74.67 µg/m³ at Shell Bus Station on Tuesdays. Our analysis underscores the urgent need for improved air quality management strategies in Freetown to mitigate health risks associated with elevated airborne particulate levels. In conclusion, this study serves as a pivotal contribution to understanding air quality dynamics in Freetown's urban transit environment, providing essential data for stakeholders to address public health concerns linked to air pollution. Recommendations include implementing stricter vehicle emissions regulations, enhancing public transportation options, and promoting community awareness initiatives surrounding air quality. These measures are critical in fostering a healthier urban environment for residents and commuters alike.Item AI-ENHANCED INTRUSION DETECTION FOR INDUSTRY 4.0: A CROSS-REGIONAL STUDY ON MITIGATING ADVANCED PERSISTENT THREATS IN CYBER-PHYSICAL SYSTEMS(2025-08-30) Koroma, MohamedThis study proposes an AI-enhanced Intrusion Detection System (IDS) framework to combat Advanced Persistent Threats (APTs) in Cyber-Physical Systems(CPS)across diverse regional infrastructures. Traditional IDS struggle in resource-constrained environments, with high false positives(72% in Nigeria)and poor adaptability.TheCOVID 19 pandemicworsened vulnerabilities, leaving 68% of manufacturers without real-time OT monitoring. Our solution integrates federated learning (FL) for decentralized training, explainable AI (XAI) for interpretable alerts, and quantum-resistant cryptography for long-term security. This study tackles four challenges namely the 52% energy savings in Africa via 8-bit models, why FL maintains >90% accuracy in low-bandwidth networks, XAI boosts operator trust by 21% in Kenya, and the 96% quantum resilience. Validated across Africa (Kenya), Asia (India), and the West (USA) using real-world datasets (SWaT) and synthetic APTs, the framework achieves 93.2% detection accuracy with a 4.1% false positive rate, outperforming traditional IDS by 27% while reducing bandwidth by 62% and energy use by 42.9%. Field tests in Kenya showed a 35% increase in operator trust due to XAI transparency. Ethical safeguards include differential privacy in FL to protect sensitive data and adherence to ITU-D Ethical AI Guidelines for operator consent in field trials.Item The Use of Digital Register Systems and Perceived Data Quality and Reporting Timeliness at Peripheral Health Units in Nongowa Chiefdom, Kenema District, Sierra Leone(2026-09-22) Kortu, JosephRoutine health data support decision-making only when they are accurate, complete, and available on time. This study examined the use of digital register systems (DHIS2 and eIDSR) and the associated data quality and reporting timeliness at Peripheral Health Units (PHUs) in Nongowa Chiefdom, Kenema District, Sierra Leone. A descriptive cross-sectional survey used a Yamane (1967) sample of 100 health workers from purposively selected PHUs; 96 consented and completed a structured questionnaire (96% response rate), supported by a facility record-review checklist. Data were analyzed descriptively in SPSS. The workforce was experienced and largely trained (95.8%), operating mainly within DHIS2 but entering data monthly rather than at the point of service, with 87.5% still keeping full paper registers. Respondents perceived high accuracy and completeness, driven by validation rules and mandatory fields, and rated timeliness as the strongest dimension. Dominant barriers were unreliable power and connectivity, workload, duplication, staff turnover, and training gaps. The perceived gains remain conditional on infrastructure and workforce stability.Item Integrated neutral-hydrolysis recycling of mixed poly(ethylene terephthalate) and poly(butylene terephthalate) waste: System-level design, techno-economic, and environmental evaluation(Elsevier BV, 2026-06-30) Boré, AbdoulayeMixed poly(ethylene terephthalate)/poly(butylene terephthalate) (PET/PBT) waste represents an increasing fraction of heterogeneous polyester streams with limited compatibility with mechanical recycling within municipal material recovery facilities. This study evaluates a continuous neutral-hydrolysis process for a nominal 70/30 PET/PBT feed using Aspen Plus simulation, techno-economic analysis, and cradle-to-gate life-cycle assessment (LCA). The framework integrates literature-based reaction kinetics with simulated separation, economic, and environmental inventories to assess the system-level implications of mixed PET/PBT neutral hydrolysis. At 270 °C, 60 bar, and 30 min residence time, the simulation predicted 80.75 kg/h terephthalic acid (TPA) in the recovered solid cake from 100 kg/h mixed PET/PBT feed, corresponding to 97.1 % of the stoichiometric maximum. The recovered cake contained 96.45 wt% TPA prior to product polishing. Thermal demand is concentrated in hydrolysis and downstream separation, with the base-case simulation used to quantify external utility requirements. A separate pinch-based utility-displacement analysis indicates that recovering roughly 40 % of the available hot-cold overlap could reduce external utility demand; this value represents a thermodynamic integration target, not demonstrated heat-exchanger-network performance. With glycol coproduct credits included, the estimated minimum selling price was \$3.66/kg TPA, while LCA estimated a greenhouse-gas intensity of 2.68 kg CO 2 -eq/kg TPA. Within the modeled system boundary, neutral hydrolysis may complement mechanical recycling for PET/PBT-rich waste streams. Pilot-scale validation with representative mixed PET/PBT feedstocks and assessment of contaminant partitioning, solids handling, and recycle-water stability remain essential next steps.