Arabian Journal for Science and Engineering最新文献

Saudi Arabia’s energy portfolio is shifting toward low-carbon solar photovoltaics (PV) and nuclear energy. PV intermittency and seasonality must be considered along its low cost which reached globally low value of (text{c}!!| 1.04/kWh_{e,PV}) in SA. Nuclear power plants, NPPs, are reliable and cost stable: (text{c}!!| 4.2 - 7.1/kWh_{e,NPP}). NPP requires (2.7{text{liter}}/kWh_{e,NPP}) freshwater for evaporative cooling stressing water resources. NPP is best operated at constant maximum power avoiding xenon poisoning operational complexity and keeping capital intensive LCOE low. This paper explores alternative roles for NPPs in Saudi Arabia: base-load electricity generation, dedicated desalination, and functioning as energy hub integrating energy storage systems and PV power. Base-load operation is not competitive compared to combined cycle gas turbine (CCGT) or future PV/battery systems. NPP can operate thermal and membrane desalination with good economics of (293.7{text{liter}}/kWh_{e}) and energy cost component of ($ 0.14 - 0.24/m^{3} .). Our study recommends integrating constant NPPs with intermittent PV systems using compressed air energy storage (CAES). Liquid piston used in CAES enables efficient quasi-isothermal compression/expansion. PV powers charging/compression and NPP heat powers discharging/expansion. The system includes ice thermal storage, 310 °C phase-changing-material hot storage with 200 bar high-pressure tanks storing cold air. The system enables power on demand, POD independent from PV and NPP time profiles. PV-NPP-CAES POD costs 36% less than NPP cost. Electricity generated is 2.35X higher than its NPP contribution. Integrating SA locally advantageous PV to reliable NPPs by utilizing industrially mature CAES and thermal storage represents a promising energy plan for Saudi Arabia, constituting an energy hub of low-cost and reliable power on demand.

This study explores the assessment of hazards arising from nuclear power plant incidents, informed by the Fukushima catastrophe. It evaluates the environmental impact of noble gases, such as iodine-131 releases, recognizing the limitations of current local computational tools, particularly in predicting near-field dispersion accurately. Utilizing computational fluid dynamics (CFD), this study validates this approach’s effectiveness in predicting pollutant dispersion around buildings. Among the five turbulence models tested, the Lag Elliptic Blending (EB) k-ε model emerges as the most suitable for simulating radioactive pollutant dispersion due to its superior performance in capturing flow dynamics. The findings underscore the inadequacy of traditional Gaussian plume models in accounting for the effects of buildings on dispersion patterns. Notably, simulations around the Barakah nuclear site located in the United Arab Emirates reveal the significant influence of buildings on the trajectory of radioactive pollutants from hypothetical cracks. Consequently, it advocates caution in relying solely on classical Gaussian plume models for evacuation plans, as they may overlook crucial flow patterns due to building presence, potentially leading to distorted assessments of gas distribution and deposition rates.

BPA (Bisphenol A), an endocrine disrupting compound commonly detected in various water bodies, has been found to be hazardous because it can mimic and disrupt the hormone functions in the body. Photocatalysis is among the most efficient methods for eliminating BPA from water sources. Creating efficient heterojunctions has been shown as a successful approach to tackle the main obstacles encountered by a single photocatalyst and, thereby, improving photocatalytic performance. Thus, choosing the right dopant and/or semiconductor for the formation of an effective heterojunction is crucial to ensure the cost and production feasibility for upscaling is viable. A simple two-step calcination method was employed in this work to synthesize N-TiO₂/g-C₃N₄, where g-C₃N₄ served not only as a precursor for the preparation of the heterojunction but also as a source for nitrogen doping of TiO₂ to promote the photocatalytic degradation of BPA. The optimized N-TiO₂/g-C₃N₄ with a mass ratio of 1:2 (TGN-2) resulted in the optimal photocatalytic degradation of BPA, which was 7.23 times better than pure TiO₂. The enhanced photocatalytic performance of the composite may be attributed to the establishment of the Ti–N bond, higher crystallinity of TiO₂ anatase, and better separation of photoinduced charge carriers compared to other synthesized composites.

In the complex field of nuclear reactor design and analysis, there is a continuous need for sophisticated computational models that can accurately capture the diverse and challenging thermal hydraulic phenomena during steady-state and transient conditions. This research sets the stage for the development of a comprehensive system analysis code for nuclear reactor thermal hydraulic design, starting with a fully implicit isentropic two-fluid model with four governing equations. The computational methodology for this model incorporated the Advection Upstream Splitting Method scheme with a staggered grid arrangement. The nonlinear system of governing equations was solved implicitly by employing Newton’s method while a numerical Jacobian matrix was calculated for the derivative terms, enhancing the stability and efficiency of the solution process. The performance of the model was assessed using three classical two-phase benchmark problems: water faucet problem, oscillating manometer problem, and air–water phase separation problem. The validation results indicate a reliable and accurate prediction of the model. Consequently, the successful development and validation of current two-fluid isentropic model provide a solid foundation for the future development of a comprehensive nuclear system analysis code based on the two-fluid model.

Shear failure in RC beams can lead to sudden and catastrophic collapse, posing significant risks to the occupants and the structure itself. The computation of the shear capacity of reinforced concrete beams is essential to ensure structural safety and stability. Proper shear strength calculations guide the design and reinforcement requirements, ensuring the beam can safely carry the expected loads. The present study aims to investigate the applicability of the shear design provisions of ACI 318-14, ACI 318-19, and EN 1992-1-1:2004 for self-compacting concrete (SCC), recycled aggregate concrete (RAC), and geopolymer concrete (GPC) reinforced concrete slender beams. For this purpose, a database of 411 slender reinforced concrete beams (150-SCC, 200-RAC, and 61-GPC) was compiled from 62 studies published between 2001 and 2023. Statistical analysis was performed to ascertain the accuracy of various design codes for the evaluation of the shear capacity of reinforced concrete beams cast with SCC, RAC, and GPC beams. The theoretical shear capacities and strength ratios (S/R) were calculated for each member using the provisions of ACI 318-14, ACI 318-19, and EN 1992-1-1:2004. The average (S/R), standard deviations, and coefficient of variance (COV) were also calculated for each code. For SCC, RAC, and GPC beams without shear reinforcement, the average S/R was found to be maximum for EN 1992-1-1:2004, followed by ACI 319-19 and ACI 318-14. The average S/R for ACI 318-14 and ACI 318-19 was found to be similar and higher than the average S/R yielded by EN 1992-1-1:2004 for beams with shear reinforcement. The consistency in the prediction of shear capacity was better for ACI 318-19, with an average COV of 16% for SCC and RAC beams and 29% for GPC beams without shear reinforcement. Overall, the performance of ACI 318-19 was found to be better than the other two codes, with a maximum number of conservative results. Finally, the failure modes of RC beams cast with SCC, RAC, and GPC are discussed. The failure modes in terms of crack initiation and propagation for SCC, RAC, and GPC beams were found to be identical to conventional concrete beams.

Herein, a series of CeNi_1-xCo_xO₃ (x = 0.1, 0.3, 0.5, and 0.7) was prepared by a co-precipitation method for combined steam and CO₂ reforming of methane (CSCRM) reaction. The influence of incorporating Ni with Co species in the perovskite structure was elucidated by both the catalytic performance and physicochemical properties of as-prepared materials. Several modern techniques were utilized to study the catalysts’ properties, including XRD, EDS, SEM, HR-TEM, Nitrogen adsorption–desorption, H₂-TPR, CO₂-TPD, and Raman spectroscopy. As Co modification content increased, respective to x value in CeNi_1-xCo_xO₃ change from 0.1 to 0.5, calcined catalysts’ crystallite size of separated M₂O_x oxides gradually increased from 16.2 to 20.3 nm. Investigating the CO₂-TPD and H₂-TPR profiles showed that CO₂ adsorption ability of catalysts increased while reducibility decreased when x value increased from 0.1 to 0.5. Despite clearly change of physicochemical properties, the Co content in range of x = 0.1–0.5 did not have significant influence on the catalytic activity in CSCRM reaction. The properties of catalyst with higher Co content (x = 0.7) changed differently compared to catalysts with x = 0.1–0.5, which seemed positive (smaller crystallite sizes of calcined perovskite and reduced metallic phases of 12.9 nm and 12.8 nm, respectively; slightly larger specific surface area of 13.0 m²/g, higher hydrogen consumption in TPR analysis), but the catalytic activity of this catalyst slightly lower than other surveyed catalysts at a low temperature of 550 °C. Despite that, all studied catalysts showed quite similar catalytic performance at high temperature range, which was considered as favorable operation condition for the reaction. The study also revealed an excellent coke tolerance ability of perovskite-derived catalysts in the CSCRM. The as-prepared CeNi_0.5Co_0.5O₃ catalyst showed a comparable activity compared to other published results on other catalysts, with CH₄ and CO₂ conversions of 94.6% and 93.2%, respectively. The comparison with other studies also revealed a high CH₄ conversion rate of 6381 mL_CH4.g⁻¹.h⁻¹ and an excellent CO₂ conversion rate of 3269 mL_CO2.g⁻¹.h⁻¹ on CeNi_0.5Co_0.5O₃ in a high space velocity of 3 × 10⁵ mL.g⁻¹.h⁻¹.

Lithium present in Bayer liquor enters the alumina during the seed decomposition process, subsequently increasing energy consumption in the aluminum electrolysis process, which is environmentally unfriendly. Combined with the global demand for lithium and the alumina industry’s pursuit of high-quality alumina, it highlights the essential need for lithium recovery in the alumina production process. This study utilized Amberlyst35 resin as an adsorbent for the adsorption of lithium from Bayer mother liquor. Under experimental conditions consisting of a causticity ratio of 1.5 in sodium aluminate solution, lithium ion concentration of 6.8 mmol/L, and a reaction temperature of 70 °C maintained over a 240-min period, the resin exhibited a lithium adsorption capacity of 5.88 mmol/g and a removal efficiency of 69.18%. The adsorption process was fitted with the pseudo-second-order kinetic model and Langmuir isotherm model, and the theoretical saturation adsorption capacity of lithium was 6.485 mmol/g. The adsorption process is an endothermic process and occurs spontaneously. Analytical techniques, specifically Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, revealed the presence of sulfonic acid groups (–SO₃H) within the resin. A notable reduction in the peak intensities associated with these sulfonic acid groups post-adsorption suggested a direct interaction between the lithium ions and the sulfonic acid functionalities of the resin.

The modern world produces vast amounts of wastewater due to rising human activity, industry, and urbanization. Physicochemical and biological techniques are commonly utilized for the degradation of industrial wastewater and have proven to be highly effective in eliminating contaminants. However, some pollutants in industrial wastewater are very hard to eliminate with conventional physicochemical and biological methods, growing interest in using electrochemical oxidation (EO) for efficiently degrading industrial wastewater recently. This review mainly focuses on the effectiveness of different electrode materials in the EO process for wastewater treatment. The scope of research in this field is broad, and the purpose of this review is to evaluate how much interest there is in each field of industrial wastewater treatment. Since 2011, Science Direct has collected the number of annual articles directly relevant to electrode materials used for EO. A bar graph was used to analyze the evolution of research analyses from 2011 to 2023. According to this study, interest in electrode materials used for EO of wastewater treatment has increased throughout the past 13 years. In this paper, different electrode materials and industrial wastewater are discussed. The constantly growing trends in electrode materials used for EO of wastewater show that this technology is still in demand, and this interest should materialize into new applications for a sustainable and assured future.

Pressure-retarded osmosis (PRO) has a chemical potential to generate sustainable energy by utilising a semi-permeable membrane. RO-brine management with effluents being disposed of and energy usage are two issues that RO systems and deionised units face. The energy generation using the PRO techniques is proposed to address both of these issues practically. PRO can be used and integrated with the configuration of RO-brine as draw solution (DS) and effluent from demineralisation unit as feed solution (FS) that may generate the osmotic power density when it is applied. In this study, osmotic pressure for DS and FS was computed experimentally to predict ({text{W}}_{text{p}}) of the PRO, and the performance of the PRO process was evaluated using various scenarios, which included the spatial process parameters of applied pressure, concentrations and flow rates for DS and FS. In this approach, the effluent solutions could serve as an inflow source. Additionally, there is no need for pre-treatment of the DS and FS, as is required in the common PRO system. Experiments were conducted to estimate the transport properties of commercial SW-membranes. Based on these experimental scenarios, trials were conducted using three DS of NaCl concentrations of ~ 51.8, 44.1, and 36.2 g/L to investigate the viability of the PRO, where the largest ({text{W}}_{text{p}}) reached 2.83, 2.32, and 1.94 W/m², while the smallest ({text{W}}_{text{p}}) was 1.5,1.18, and 1.0 W/m², and the flux reversal point of the ({Delta text{p}}_{text{PRO}}text{ was})~10.8 bar and 9.4 bar, corresponding to the different flow rates. Additionally, the effects of dilution on the system were also observed.

The accelerating global energy crisis and the worsening impacts of climate change have heightened the demand for alternative energy sources. Wind energy is one of the most reliable, affordable, efficient, and readily available renewable sources for residential and industrial use. In response, vertical axis wind turbines (VAWTs) have garnered significant recognition in recent years, leading to increased development and widespread implementation across the globe. A VAWT is a type of wind turbine (WT) known for its compact design, ease of maintenance, and competence in utilizing wind from multiple directions, making it highly suitable for city landscapes. The global impact of VAWTs is significant, as they contribute to the reduction of carbon emissions and the transition toward a more sustainable energy future. Despite these benefits, VAWTs face drawbacks, including lower performance than horizontal axis wind turbines and challenges with achieving consistent self-starting under varying wind speed (({U}_{infty })) conditions. This work primarily explores scientific literature and contemporary advancements in VAWT research. The study examines the existing research gaps, challenges, and potential future directions for these turbines and their applications. The outcomes of different strategies are thoroughly evaluated, with the most effective methods highlighted. Consequently, this review offers comprehensive insights into the challenges and solution approaches associated with VAWTs, paving the way for future research to improve aerodynamic performance.