http://hdl.handle.net/11189/454 2026-10-16T01:14:07Z http://hdl.handle.net/11189/10935 Title: Between addiction and immersion: a correlational study of digital and academic behaviour among Engineering students Authors: Hkoma, Mustafa Ben; Almaktoof, Ali; Rugbani, Ali Abstract: Abstract In the age of digital transformation, where students increasingly rely on technology for learning and communication, concerns arise regarding its potential association with academic outcomes. This study quantifies the relationship between Digital Behaviour (DB) and Academic Behaviour (AB) among engineering undergraduates at Misurata, Al-Asmarya Islamic, and Al-Marqab universities in Libya. DB is conceptualised as a spectrum ranging from excessive, compulsive device use (addictive behaviour) to purposeful academic technology use (digital immersion). Using a descriptive-analytical design, a convenience sample of 300 undergraduate engineering students completed a validated 20-item questionnaire (Cronbach’s α = 0.711–0.899 for subscales). Data were analysed using descriptive statistics, Pearson correlation, simple regression, and analysis of variance (ANOVA) in the Statistical Package for the Social Sciences (SPSS) v23. The analysis identified a weak but statistically significant positive correlation between students’ DB and their AB (r = +0.19, p = 0.002). Notably, AB scores increased in the senior study years, while digital engagement remained consistently high across all years, suggesting an evolving capacity among students to regulate their digital habits. ANOVA results revealed significant differences in AB by year of study, while gender showed no significant overall association. These findings contradict the conventional assumption that heavy digital use uniformly diminishes academic outcomes; instead, in digitally immersed learning environments, strategic DB may coexist with or support academic performance. The study concludes that DB is not inherently detrimental to AB and may provide benefits when managed effectively, especially among more advanced engineering students. It recommends early educational interventions that promote digital self-regulation and the strategic use of technology for academic purposes. 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10928 Title: A metaheuristic approach to analyze the techno-economical impact of energy storage systems on grid-connected microgrid systems adapting load-shifting policies Authors: DEY, BISHWAJIT; Krishnamurthy, Senthil; Fose, Nande; Ratshitanga, Mukovhe; Moodley, Prathaban Abstract: Battery energy storage systems (BESSs) and plug-in hybrid electric vehicles (PHEVs) are essential for microgrid operations to be financially viable. PHEVs can serve as mobile storage devices, storing excess energy during times of low demand and delivering it during times of high demand. By offering reliable on-site energy storage, BESSs improve cost efficiency by allowing the microgrid to store cheap, off-peak electricity and release it when prices increase. To minimize generation costs and alleviate grid stress during periods of high demand, load-shifting policies shift inelastic loads to off-peak hours when energy prices are lower. When combined, these tactics support dependable, affordable, and effective microgrid management. A recently developed RIME algorithm is used as the optimization tool to reduce the total operating cost (TOC) of an MG system for three cases and three situations. The cases emphasize a modified load demand style influenced by the optimal load-shifting method (OLSM) and order characteristics load-shifting policy (OCLSP), whereas the situations refer to the inclusion of ESS in the MG system. The TOC decreased from $2624 without ESS to $2611 and $2331 with PHEVs and BESSs, respectively. These costs were further reduced to $1192, $1162, and $1147, respectively, when OLSM was implemented to restructure the base load demand. Additionally, a balance between a minimal TOC and carbon emission was obtained when an OLSM-based load demand model was used with BESSs. The RIME algorithm outperformed many recently developed algorithms and is consistent and robust, yielding better quality solutions. 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10926 Title: Measurements of thermodynamic properties and activity coefficients at infinite dilution of selected organic solutes and water in a deep eutectic solvent (choline chloride +1,3 propanediol) Authors: Mbatha, Banzi P.; Ngema, Peterson T.; Ramsuroop, Suresh; Tumba, Kaniki; Lindokuhle Manyoni; Nkosi, Nkululeko Abstract: In this study, a deep eutectic solvent (DES) consisting of choline chloride (ChCl) and 1,3 propanediol (Pdiol) at a 1:2 M ratio was evaluated experimentally for its extractive efficiency. The important DES’s physicochemical properties: density, viscosity, and refractive index, were measured at T = (293.15–353.15) K and 101.3 kPa. Solvent intermolecular interaction strengths against 32 selected organic solutes were assessed using experimental infinite dilution activity coefficients (IDAC) measured at T = (313.15 to 343.15) K and 101.3 kPa. The interactions between the solute and solvent molecules were further characterised by partial molar excess properties (ΔH E,∞ i pacity (k ∞ , ΔG ∞ j E,∞ i and T ref ΔS E,∞ i ). The separation ability of the solvent was assessed using selectivity (S ij ) and ca) as thermodynamic separation parameters. DES indicated stronger interactions with more polar molecules. The findings indicate that DES is suitable for separating the alkanes from alcohols, acetonitrile or thiophene mixtures. This work adds to the DES database and offers a theoretical framework for industrial separation problems. 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10924 Title: Cost optimization model for a grid connected offshore wind and tidal power generation system using HOMER: A case study in Buffels Bay, South Africa Authors: kangaji, ladislas; Atanda Raji; Orumwense, Efe Abstract: This study presents a cost optimization model for a grid-connected offshore wind and tidal power generation system, using Buffels Bay, South Africa, as a case study. The research utilizes the Hybrid Optimization Model for Electrical Renewable (HOMER) software to design and analyze a hybrid power system that integrates wind turbines, tidal energy, and battery storage with the local grid. Various system configurations were simulated to identify the most cost-effective solution, targeting the lowest Levelized Cost of Energy (LCOE) for a proposed 20 MW load. The optimized model combines tidal and wind power, contributing 62% and 20% of the total energy, respectively, demonstrating significant potential for renewable energy integration. The findings highlight the benefits of using a hybrid system to enhance reliability and reduce energy costs. Despite the low cost of coal-generated electricity in South Africa, the study shows that offshore wind and tidal energy can provide a sustainable and economically viable alternative, contributing significantly to the region's energy mix. This work offers valuable insights for future renewable energy projects in coastal regions with similar environmental and economic conditions. 2025-01-01T00:00:00Z