Search Results (1,349)

The PZBLC glass system, with the molar composition 40P₂O₅–30ZnO–10BaF₂–18LiCl–2.0CdO (mol%), was fabricated and subsequently doped with Eu₂O₃ and Tm₂O₃ using a melt-quenching technique. The thermal stability (ΔT), glass transition temperature (T_g), and linear refractive indices of the fabricated glass were evaluated. The spectroscopic parameters Ω₂, Ω₄, and Ω₆, and the measured visible and near-infrared photoluminescence at the excitation wavelength depend on the type of rare-earth ions in the doped glasses and were estimated. The lifetimes of the relevant transition levels and the gain bandwidths (σ_em × Δλ_eff) of the fabricated glasses were evaluated. The PZBLC–Eu³⁺ glass, excited at 395 nm, exhibits an intense, high-purity red emission, whereas the PZBLC–Tm³⁺ glass, excited at 357 nm, shows a strong blue emission. The fabricated glasses are promising candidates as a solid source for visible-light emission with a high emission cross-section prepared by a low-cost technique. Full article

Self-healing biomaterials have attracted significant attention due to their ability to restore structural integrity, extend material lifetime, and reduce maintenance costs without external intervention. In this study, Polyvinyl Alcohol/Graphene Oxide/Eggshell Particle (PVA/GO/ESP) composite hydrogels were synthesized via a freeze–thawing method and characterized using XRD, SEM/EDS, and FTIR analyses. The effect of ESP incorporation on the self-healing and mechanical properties of the hydrogels was systematically investigated. Tensile test results demonstrated that incorporation of 1 wt% ESP improved the tensile strength up to 0.326 MPa while maintaining high strain capacity. Healing efficiency values calculated from recovered tensile strength showed approximately 69%, 47%, and 67% recovery for PVA/GO, PVA/GO/ESP (0.5%), and PVA/GO/ESP (1%) hydrogels, respectively. The developed hydrogels demonstrated rapid self-healing behavior at room temperature without external stimuli. These findings suggest that ESP-reinforced PVA/GO hydrogels may serve as promising candidates for future biomaterial and soft tissue engineering studies. The developed hydrogels demonstrated enhanced tensile strength, rapid self-healing behavior, and promising swelling properties, indicating their potential use in soft tissue engineering and biomaterial applications. Full article

Renewable energy technologies have historically been offered market support to facilitate their deployment and aid the transition away from fossil fuels. This work shows the costs of subsidising utility-scale renewable electricity generation in the UK, focusing on wind, solar and tidal stream technologies in the Renewables Obligation (RO) and Contracts for Difference (CfD) schemes. The subsidy of each technology is calculated using published data, including an estimate of committed costs over the full project lifetime, which is not always assessed. For the technologies considered, the RO supported 24.8 GW of installed capacity at a lifetime cost of about £103 bn. To date, CfD have been awarded for 45.3 GW of wind, solar and tidal stream, with total lifetime cost of £40 bn, although this is sensitive to future gas generation costs, with a range of £8–71 bn. The CfD scheme offers better value for money to consumers than the previous RO schemes, and this is true for all technologies assessed. By design, the CfD also helps to insulate billpayers from spikes in the wholesale market caused by high fossil fuel prices, decoupling the costs of electricity from gas. Credible scenarios for future deployment out to 2050 are also presented, along with discussion of potential socioeconomic benefits and the mechanisms to achieve these. Full article

Oil and gas pipelines are critical infrastructures that require continuous and reliable monitoring to detect leaks, pressure anomalies, corrosion, and unauthorized activities. Wireless sensor networks (WSNs) have emerged as an effective solution for large-scale pipeline monitoring due to their low deployment cost and real-time sensing capabilities. However, the resource-constrained nature of sensor nodes and the open wireless communication environment expose pipeline monitoring systems to various routing attacks, for example, blackhole, sinkhole, selective forwarding, and false data injection attacks, while simultaneously demanding strict energy efficiency to prolong network lifetime. In this paper, we propose SEER-PM (Secure and Energy-Efficient Routing for Pipeline Monitoring): a novel protocol that integrates an Artificial neural network (ANN)-based trust mechanism with energy-aware routing metrics. SEER-PM dynamically evaluates node trustworthiness based on packet forwarding behavior, residual energy, and signal consistency. By training the ANN on historical behavioral data, the system accurately detects malicious nodes with high precision. Simulation results demonstrate that SEER-PM outperforms existing secure routing protocols (Sec-AODV and T-LEACH) in terms of packet delivery ratio (PDR) by 14%, detection rate by 9.5%, and network lifetime by 12% under heavy attack scenarios. The proposed protocol enhances the reliability, security, and sustainability of pipeline monitoring WSNs operating in harsh and remote environments. Full article

The accelerated global transition toward eco-friendly mobility has necessitated robust decarbonization measures across the maritime sector, with battery-powered electric propulsion ships emerging as a promising alternative. Accordingly, the applicability of silicon carbide (SiC)-based technology to propulsion inverters, a key component of such vessels, is currently under investigation. Although life cycle assessment (LCA) studies comparing conventional silicon (Si)-based and SiC-based inverters have been conducted previously, these analyses neglect realistic operating profiles and load fluctuations, limiting their applicability. Furthermore, life cycle cost assessment (LCCA) integrating real-world operating conditions has rarely been addressed. To address these gaps, this study conducted a comparative LCA and LCCA of Si IGBT and SiC MOSFET inverters for marine electric propulsion systems across three vessel types: a cruise ship, a passenger and car ship, and a recreational boat, incorporating real-world load profiles to evaluate global warming potential (GWP), fossil depletion (FD), and cumulative energy demand (CED). The static LCA results showed negligible differences between inverter types, contributing less than 1% to total impacts. The dynamic LCA demonstrated that SiC MOSFET inverters reduced environmental impacts by approximately 57%, 52%, and 34% for cruise ships, passenger and car ships, and recreational boats, respectively. Despite a 40% higher initial investment cost, SiC inverters achieved payback periods well within vessel lifetimes across all vessel types. These findings support SiC inverters as a sustainable and economically viable solution for ship electrification. Full article

The intermittent nature of renewable energy systems and the mismatch between power generation and load demand necessitate the integration of efficient energy storage systems (ESSs). Among large-scale energy storage technologies, pumped hydro-energy storage systems (PHESs) are widely recognized as one of the most cost-effective and longest-lifetime storage solutions under favorable geographical conditions. This study proposes and optimizes a hybrid renewable energy system (HRES) for the Wadi Baish region in Saudi Arabia as a real case study, where the significant elevation difference between the nearby mountains and the existing lake provides favorable conditions for PHES implementation. A nested optimization framework is developed to determine the optimal sizing and operation of the HRES components. The external optimization loop employs the non-dominated sorting genetic algorithm II (NSGA-II) to optimize system sizing, while the internal optimization loop uses mixed-integer linear programming (MILP) to optimally dispatch the PHES, battery energy storage system (BESS), and hydrogen energy storage system (HESS). In addition, demand-side management (DSM) is coordinated with the MILP dispatch strategy to improve system performance and reliability. The results show that the optimized system can supply a 10 MW average load with a renewable energy penetration of 98.7%. The proposed configuration achieves a total lifecycle cost of USD 231.37 million and avoids approximately 898.58 kt of CO₂ emissions over the project lifetime. PHES operates as the primary bulk energy storage technology due to its high storage capacity and low degradation characteristics. Furthermore, the degradation-aware model predicts battery replacement every 12 years and HESS replacement every 5 years. Compared with rule-based control, the MILP-based dispatch strategy reduces grid dependency by 87%. The coordinated DSM and MILP operation also reduces the levelized cost of energy to USD 0.066/kWh while improving overall system reliability. These findings demonstrate the importance of coordinated energy management and accurate degradation modeling in the optimal design and operation of renewable-based HRES configurations. Full article

Hydropower-dependent electricity systems, such as Ecuador’s, face critical supply disruptions during droughts: a vulnerability exemplified by the 2024 power outages. This study assesses the technical, economic and environmental feasibility of a 200.84 MWp grid-connected solar photovoltaic (PV) plant proposed for the Pacific Refinery site in Manabi, Ecuador, as a strategy to diversify the energy matrix and reduce hydrological risk. Using site-specific solar resource data (4.65 kWh/m²/day) and PVSyst simulations, the plant achieves an annual energy production of 295 GWh with a performance ratio (PR) of 85.3%. A discounted cash flow analysis over 25 years, assuming a 7% discount rate and an electricity price of 60 USD/MWh, yields a net present value (NPV) of 104.9 MUSD, an internal rate of return (IRR) of 62.2%, and a levelized cost of energy (LCOE) of 14.5 USD/MWh, well below current industrial tariffs in Ecuador. Sensitivity analysis confirms project viability under ±15% variations in investment cost, energy price, and solar resource. Over its lifetime, the plant avoids 1.83 Mt of CO₂ emissions, supporting national decarbonization goals. The results demonstrate that large-scale PV deployment in high-radiation, low-latitude regions can be highly profitable and contribute to energy sovereignty in hydropower-dependent systems. Furthermore, this study provides a replicable model for repurposing unused industrial land for renewable energy generation, offering actionable insights for policymakers and investors in developing economies. Full article

The DC/AC ratio is a critical design variable in utility-scale photovoltaic (PV) systems because it governs inverter loading, clipping behavior, energy yield, and long-term economic performance. However, conventional sizing approaches often rely on heuristic rules or deterministic annual yield optimization without explicitly accounting for the thermodynamic, optical, and stochastic mechanisms that reshape the DC power envelope. This study develops a physics-informed and bankability-oriented PVsyst-based framework for optimal DC/AC sizing by integrating irradiance transposition, incidence-angle modifier losses, temperature-dependent semiconductor behavior, inverter clipping dynamics, degradation, and discounted lifetime levelized cost of electricity (LCOE). A 10 MWp fixed-tilt PV plant located in Western Türkiye under Mediterranean climatic conditions is analyzed. The base-case simulation yields 15.20 GWh/year with a specific yield of 1519 kWh/kWp/year and a performance ratio of 87.5%, while temperature losses are identified as the dominant loss mechanism, accounting for 6.21% of the annual energy reduction. A regression-based thermal sensitivity analysis shows that monthly PR decreases by approximately $4.9\times {10}^{-3}$ per °C increase in ambient temperature. The DC/AC sweep identifies an optimum range of 1.35–1.40, where improved inverter utilization balances nonlinear clipping growth. A temporal clipping analysis confirms that clipping is concentrated during summer midday periods and is sensitive to sub-hourly irradiance variability. Correlated Monte Carlo simulations and LCOE cost-sensitivity analyses demonstrate that the optimum remains structurally robust under uncertainty, degradation, and inverter cost assumptions. The results show that DC/AC sizing should be treated as a coupled thermodynamic–optical–electrical–economic optimization problem rather than a simple capacity-matching decision. Full article

The building sector is a major contributor to global energy consumption and greenhouse gas emissions, and multi-family residential buildings play an important role in urban decarbonization and the transition toward sustainable cities and societies. This study proposes decarbonization-oriented case studies for selecting heating, ventilation, and domestic hot water systems by integrating environmental, economic, and social criteria aligned with the Sustainable Development Goals (SDGs), particularly SDG 7 and SDG 11. This research compares selected conventional and low-carbon building-level heating, ventilation, and domestic hot water systems, including gas boilers and heat pumps integrated with renewable energy and heat recovery. The evaluation is based on a calculation-based energy performance assessment using a quasi-static monthly heat balance approach, economic indicator analysis, and environmental assessment based on primary, final, and useful energy demand and CO₂ emissions. Cooling energy demand was not included in the assessment because the analyzed scenarios were limited to heating, ventilation, and domestic hot water preparation. Furthermore, the social implications are examined, considering energy affordability, long-term operating costs, and the potential to mitigate energy poverty. The results indicate that low-carbon HVAC systems, particularly heat pump systems integrated with renewable energy sources, significantly reduce CO₂ emissions and primary energy consumption compared to conventional solutions. Although they require a higher initial investment, they can achieve lower life cycle costs over the building’s lifetime. The study concludes that holistic, decarbonization-oriented technologies can support cost-effective, socially responsible pathways toward low-carbon, energy-efficient multi-family residential buildings and sustainable urban development. Full article

Solid-state batteries (SSBs) are emerging as a transformative alternative to conventional lithium-ion batteries (LIBs) for next-generation electric vehicles (EVs) by replacing flammable liquid electrolytes with solid-state materials. Compared with current LIB systems delivering approximately 160–300 Wh/kg at the pack level, SSBs are projected to achieve 400–800 Wh/kg, enabling improvements in driving range of nearly 50–100% while simultaneously reducing battery pack mass by 10–30%. These improvements directly enhance vehicle-level energy efficiency by lowering energy consumption from typical values of 150–180 Wh/km in present EVs to projected levels of 110–140 Wh/km in optimized SSB-based architectures. Furthermore, reduced internal resistance and improved electrochemical stability can increase round-trip efficiency from approximately 85–95% in conventional LIBs to values approaching 95–98% under optimized solid-state configurations. The enhanced thermal stability of solid electrolytes significantly reduces the need for active cooling systems, decreasing parasitic thermal-management energy consumption from 10–30% of total vehicle energy demand to below 5–15% in advanced SSB systems. Fast-charging capability is also substantially improved, with projected charging times decreasing from 20–40 min to approximately 10–15 min for 10–80% state-of-charge operation, while maintaining improved safety and reduced risk of thermal runaway. In addition, SSBs demonstrate projected cycle lifetimes exceeding 3000–5000 cycles, compared with 1000–2000 cycles for conventional LIBs, thereby lowering battery replacement frequency and lifecycle energy losses. This paper examines the electrochemical fundamentals, thermal behavior, charging/discharging efficiency, and vehicle-level implications of SSB technology for EV applications. Comparative analyses demonstrate that replacing LIBs with SSBs can increase EV driving range from approximately 400 km to 700–800+ km under equivalent battery mass conditions, while also improving coulombic efficiency beyond 99.5% and reducing self-discharge rates to below 1–2% per month. Current industrial case studies from Toyota, Factorial Energy, Mercedes-Benz, CATL, BYD, QuantumScape, and Samsung SDI further confirm accelerating commercialization pathways toward 2027–2030. Overall, the study demonstrates that SSBs are not merely incremental battery improvements but represent a system-level efficiency technology capable of simultaneously enhancing energy density, reducing thermal and electrical losses, extending vehicle range, accelerating charging, and improving long-term sustainability. Despite persistent challenges related to manufacturing scalability, interfacial resistance, and cost, SSBs are positioned to become a critical enabler of highly efficient, long-range, and safer electric mobility systems beyond 2030. Full article

Carbon taxes and credits (CT&C) accelerate global deployment of carbon capture, utilization and storage (CCUS) technologies to enable energy transition. This study investigates the economic performance and resilience of floating gas-to-wire with CCUS (f-GTW-CCUS), deployed at the wellhead of stranded CO₂-rich offshore oil and gas reservoirs. The f-GTW-CCUS platform integrates a natural gas combined cycle power plant with monoethanolamine post-combustion capture (PCC-MEA), producing low-carbon electricity (23 kgCO_2e/MWh, competitive with renewables) while monetizing captured CO₂ via enhanced oil recovery (EOR). The mass and energy balance data from the proposed process configuration were obtained in the literature. Critically, f-GTW-CCUS operates on wellhead-sourced in situ-associated gas, eliminating exposure to volatile natural gas markets, and achieves a levelized cost of electricity (LCOE) of USD 67.15/MWh. Monte Carlo analysis (10,000 Gaussian iterations, 30-year lifetime, 10% discount rate, three CT&C scenarios, namely, low/medium/high) is used to quantify economic feasibility across three stochastic variables: oil, natural gas, and electricity prices, starting in the 5th year. The results demonstrate the following: (1) Case A (f-GTW without CCUS) remains economically infeasible (NPV < 0) under all price volatility scenarios due to insufficient electricity-only revenue and carbon taxation penalties; (2) Case B (f-GTW-CCUS with immediate CCUS deployment) maintains positive NPV across all scenarios, with EOR monetization contributing 43% of total revenue; (3) the critical CCUS deployment-delay threshold is 6 years under high carbon taxation, extending to 10 years when carbon credits are included. Gate-to-gate environmental assessment (carbon intensity, water footprint, land transformation) shows f-GTW-CCUS superiority versus alternative power systems, with minimal water–land nexuses due to offshore desalination. An empirical consistency assessment based on the 2026 geopolitical energy crisis demonstrates the structural resilience of the f-GTW-CCUS plant: the wellhead sourcing provides resilience to global natural gas price shocks, while the concurrent crude price escalation amplifies EOR revenues by 43–57%, improving project feasibility during commodity disruptions. These findings position f-GTW-CCUS as a critical decarbonization pathway for O&G producers exploiting stranded gas reserves. The technology combines carbon intensity reduction with economic resilience under volatile energy market conditions and mandatory climate policies. Full article

Maritime transport remains a significant source of air pollution and greenhouse gas emissions, while existing vessels face increasing pressure to comply with both local pollutant limits and emerging carbon intensity constraints. This study presents a sustainability-oriented techno-economic assessment of alternative sulphur compliance strategies using real operational data from a 1998-built cruise vessel. Three scenarios were evaluated: a counterfactual heavy fuel oil baseline, heavy fuel oil operation with open-loop scrubbers, and full switching to marine diesel oil. Pollutant emissions were estimated using a Tier 3-oriented approach, while fuel-related Tank-to-Wake greenhouse gas intensity, prospective carbon cost exposure, total cost, break-even fuel price spread and sensitivity analyses were integrated into a decision support framework. Results show that scrubbers reduce SO_x emissions by 96.9%, but increase fuel consumption, CO₂ emissions and NO_x emissions by approximately 3.6%. Marine diesel oil switching reduces SO_x by more than 99%, particulate matter by 88.8% and CO₂ by 4.6%, while also lowering prospective carbon cost exposure. However, under base case fuel price assumptions, heavy fuel oil operation with scrubbers remains the lower cost strategy, with a 2035 cost advantage of 4.03 to 5.30 million USD/year, depending on the carbon cost scenario. The findings show that the contribution of sulphur compliance strategies to sustainable maritime operation depends strongly on fuel price spreads, carbon cost exposure and remaining vessel lifetime under evolving regulatory conditions. By quantifying the trade-offs between local air pollution reduction, fuel-related carbon exposure and economic viability, this study contributes to sustainable maritime decision-making for aging vessels and supports compliance planning under regulatory uncertainty. Full article

Front-End Planning (FEP) is the very early stage of delivering megaprojects, during which strategic decisions are made that can dictate the project’s overall costs and timelines over the lifetime of the project. While existing FEP frameworks provide valuable insights into managing FEPs in Western nations, they have never been validated by reviewing Saudi Arabia’s unique environment, where large-scale projects are characterized by complicated multi-agency coordination systems and rapid timelines due to Vision 2030 initiatives. This exploratory research examines which FEP activities are most strongly associated with cost and schedule variances in Saudi megaprojects. A quantitative survey was administered to 35 respondents who have experience working on projects with a minimum of SAR 1 billion in capital cost to evaluate the quality of 33 FEP activities organized into five domains. Cronbach’s alpha validated domain composite scores, with four of five domains demonstrating good to excellent reliability (α = 0.73 to 0.91); the Technical Planning domain (α = 0.583) was excluded from regression analysis due to insufficient internal consistency. Multiple regression analysis examined associations between domain composites and project outcomes. Schedule performance was significantly associated with FEP quality (R² = 0.34, p = 0.012), with Project Planning showing a large negative association (β = −0.80, p = 0.002) and Business Planning showing a significant positive association (β = 0.75, p = 0.031). However, sensitivity analysis revealed that the Project Planning finding was substantially dependent on a single influential observation, while the Business Planning association remained robust across model specifications. The cost model did not reach statistical significance (p = 0.305), attributable in part to insufficient statistical power (achieved power = 0.40). Ownership type was not significant after controlling for FEP quality. The findings suggest that Project Planning activities, including scope compilation, preliminary execution planning, cost estimation, and master scheduling, may be associated with reduced schedule variance, though this association requires confirmation with larger samples. A preliminary four-tier prioritized framework is proposed to guide resource allocation during front-end phases while acknowledging the exploratory nature of the evidence base. Full article

The desire to use space in the most rational and efficient way to address contemporary challenges leads to the necessity of creating multi-purpose space missions capable of solving a wide range of diverse tasks. This creates a demand for propulsion systems that can provide high maneuverability for modern and future spacecraft. One potential solution to increase the maneuverability of satellites is the use of electrodeless plasma thrusters with magnetic thrust-vectoring (MTVEPT). Their simple design and acceptable thrust-to-power characteristics can improve the cost-effectiveness of a space mission, increase its reliability and operational lifetime, and enable the required orbital maneuvers. This paper presents an experimental study on the ignition thresholds of a radiofrequency discharge in an electrodeless plasma thruster utilizing argon. The study is conducted over a gas flow rate range of 20 to 210 sccm, with solenoid currents from 0 to 5 A, for two magnetic field directions and two diameters of the exhaust orifice, which is varied using a diaphragm. It is found that a 93% relative reduction in the channel diameter leads to an average twofold decrease in the discharge ignition threshold, reaching a minimum value of 2.5 × 10³ V/m at a flow rate of 100 sccm. This can be used to reduce the thruster’s power consumption for the repetitive discharge ignitions when the propellant reserves are limited. Furthermore, four distinct discharge ignition regions are identified, depending on the solenoid current. The existence of a minimum threshold electric field for the discharge ignition of 4.0 × 10³ V/m is demonstrated for a multidirectional electrodeless plasma thruster without changing the discharge channel geometry within the studied parameter range, occurring at a solenoid current of I = 2 A. Full article

Polyethylene (PE) pipes are widely employed in urban gas and water conveyance systems due to their excellent corrosion resistance, cost efficiency, and long service life. However, creep-induced delayed failure remains a critical threat to long-term operational safety and may lead to leakage accidents. Accurate and efficient prediction of creep rupture life is essential for risk control and structural design. This study investigated the performance of four commercial polyethylene pipes, including two PE80-grade and two PE100-grade pipes. By combining the creep test with the critical strain criterion, an efficient and reliable method for predicting the ductile failure lifetime was developed. Creep tests were carried out on dumbbell specimens cut from PE pipes under multiple temperature and stress levels. The time-hardening model was adopted to characterize the nonlinear viscoelastic creep evolution, and the ductile failure time was determined by introducing the critical strain threshold. The predicted lifetimes were systematically validated against experimental data from long-term hydrostatic tests. Results show that the predicted failure times agree well with the measured values, verifying the accuracy and engineering applicability of the proposed method. This approach provides a high-efficiency alternative to conventional long-term hydrostatic tests, offering valuable support for material selection, safety evaluation, and engineering design of PE pipeline systems. Full article