Search Results (71)

Marine application of electrical assets can be challenging considering the upgraded targets in terms of increasing voltage, power, temperature, specific weight, dynamics, reliability and resilience. Research work has restarted, based at least on recent literature publications, on the investigation of electrothermal aging phenomenology, whose understanding would be fundamental for the design of modern and high-performance electrical and electronic asset components. There is, however, a seeming lack of remembrance on the topic, since most of these issues were already faced decades ago. This paper reconnects to past work, proposing an innovative general approach to aging rate and life modeling under combined thermoelectrical stress and showing experimental data that support the proposed models and parameters with the purpose of quantifying the extent of stress synergy. The use of aging rate additive or multiplicative models is developed, introducing a corrective coefficient whose value is an indication of the extent of synergism and of the feasibility to perform accelerated aging tests by applying electrical and thermal stress separately, rather than simultaneously. Insulating materials typically used in ship technologies, such as synthetic paper, polyamide and cross-linked polyethylene, are considered to support the proposed models. Eventually, the contribution of partial discharges to aging rate is experimentally exploited, discussed and also modeled in order to expand the electrothermal aging phenomenology to extrinsic aging (e.g., partial discharge aging). Full article

The integration of non-thermal plasma (NTP) with heterogeneous catalysis has emerged as a promising strategy for the efficient abatement of industrial volatile organic compounds (VOCs), overcoming key limitations of conventional thermal and standalone plasma technologies. This review provides a comprehensive overview of the synergistic mechanisms in NTP-catalytic systems, with particular emphasis on the bidirectional interactions between plasma and the catalyst. Specifically, plasma can activate catalysts through surface defect generation and improved metal dispersion, while catalysts, in turn, modulate plasma characteristics via localized electric field enhancement and electron energy redistribution. Furthermore, this synergy spans multiple spatiotemporal scales, linking ultrafast electron dynamics with macroscopic catalytic performance, and atomic-scale active sites with reactor-level behavior. Based on these mechanistic insights, rational catalyst design strategies are systematically discussed, including transition metal oxides, noble metals, perovskites, and metal–organic frameworks. Finally, key challenges related to catalyst deactivation, energy efficiency, and process scalability are highlighted. Future perspectives are proposed, focusing on advanced in situ diagnostics and AI-assisted material discovery to accelerate the practical implementation of NTP-catalytic technologies for sustainable VOC removal. Full article

The severe performance degradation of lithium-ion batteries at low temperatures limits their applications in extreme environments. Herein, we report the development of a low-temperature-capable 2.5 Ah 18650 cylindrical battery employing a LiNi_0.8Co_0.15Al_0.05O₂ cathode with optimized conductive additive formulations. The ternary conductive architecture is rationally designed based on dimensional complementarity: a zero-dimensional Super P (SP) nanoparticle ensures percolation through point-to-point contacts, a one-dimensional multi-walled carbon nanotube (MWCNT) establishes long-range electron highways via line-to-point bridging, and a two-dimensional graphene nanoplatelet (GNP) provides face-to-point encapsulation of active particles, mechanically buffering volume expansion and suppressing interfacial degradation. This hierarchical point–line–plane network generates redundant electron transport pathways while steric hindrance effects mitigate aggregation of each component. Through systematic comparative investigation of GNP/MWCNT/SP ternary and MWCNT/SP binary conductive systems, we elucidate the distinct roles of low-dimensional nanocarbons in electrochemical performance enhancement. Film resistivity measurements reveal that the ternary system achieves a 67% reduction in cathode resistivity (to 9.1 Ω·cm at 20 °C) compared to conventional SP (27.5 Ω·cm), outperforming previously reported binary nanocarbon systems for high-nickel cathodes (typically 40–55% reduction at comparable loadings). This enhancement is achieved at a constant total conductive additive loading of 2.5 wt%, demonstrating that dimensional optimization rather than quantity increase governs electrical transport properties. Electrochemical evaluations demonstrate that the fabricated 18650 cells deliver exceptional rate capability (10C continuous and 20C pulse discharge) and remarkable low-temperature performance (76.8% capacity retention at −40 °C under 1C). Notably, while both conductive formulations exhibit comparable rate performan ce and temperature adaptability, the ternary GNP/MWCNT/SP system demonstrates significant superiority in cycling stability, achieving 94.9% capacity retention after 1000 cycles at ambient temperature versus inferior retention for the binary counterpart. Electrochemical impedance spectroscopy analyses indicate reduced polarization and enhanced lithium-ion diffusion kinetics in the ternary system. This study establishes a high-performance low-temperature 18650 battery chemistry and provides quantitative mechanistic insights into how dimensional synergy in conductive additive design governs the rate capability, thermal behavior, and cycling stability of nickel-rich cathodes operating under extreme conditions. Full article

The present research article deals with the thermal degradation study of epoxy resins filled with hybrid nanostructured forms of carbon under oxidative conditions. In particular, the formulated polymer composites (denoted as HYB_0.1%_CNTs:GNs and HYB_0.5%_CNTs:GNs, respectively) consist of two kinds of fillers, namely multi-walled carbon nanotubes (CNTs) and graphene nanosheets (GNs), mixed together with two different total mass amounts: 0.1 and 0.5%. In both kinds of nanocomposites, three different CNT:GN mixing ratios were considered (5:1, 1:1, and 1:5, respectively), thus providing a total of six hybrid samples. The thermal behavior of these samples was studied by simultaneous thermogravimetry and differential thermal analysis (TG/DTA) under flowing air, and two processes took place in distinct temperature ranges. In each step, about 50% of mass loss is detected with an exothermic effect in the corresponding DTA curve, with the second one accompanied by an intense heat release. The kinetic analysis of the two-stage oxidative thermal degradation was investigated using a model-free isoconversional approach. A non-Arrhenian behavior of the temperature function k(T) was assumed, and lifetime prediction was estimated at temperatures close to those of the possible applications. Isoconversional analysis shows nearly constant activation energies for all composites except HYB_0.1%_5:1 (from 142 to 96 kJ·mol⁻¹), while lifetime predictions indicate that thermal stability increases with graphene content at 0.1% loading (HYB_0.1%_1:5) and with CNT content at 0.5% loading (HYB_0.5%_5:1), with uncertainties below 7%. Finally, because of the π–π bond interactions between the CNTs and the GNs dispersed in the epoxy resin matrix, an effective and remarkable electrical performance was found and a correlation with both electrical and morphological properties was established. In this regard, Tunneling Atomic Force Microscopy (TUNA) proved to be particularly powerful in allowing the simultaneous mapping of topography and localized conductive networks with exceptional sensitivity to nanofiller dispersion, such as CNTs and GNs. DC conductivity increased by up to nine orders of magnitude at 0.1 wt% hybrid loading (up to 3.73 × 10⁻⁴ S/m vs. 1.06 × 10⁻¹³ S/m for CNT-only), with nanoscale TUNA currents (−1.9 to 4.5 pA) mirroring macroscopic trends, while at 0.5 wt% all hybrids reached 10⁻² S/m, indicating reduced synergy once a fully developed conductive network is established. Full article

This study investigates the impact of TiO₂ incorporation (0, 2, 4, 6, 8 wt.%) on the structural, optical, electrical, mechanical, and antibacterial properties of electrospun PVA/PVP nanofibers. FESEM observations revealed continuous, randomly oriented nanofibrous films with an average diameter in the 77–96 nm range, depending on TiO₂ content. FTIR and XRD analyses confirmed successful nanoparticle integration, showing effective interfacial interactions and the presence of crystalline TiO₂ phases within the semi-crystalline PVA/PVP matrix. Optical studies demonstrated a progressive decrease in the indirect band gap with increasing TiO₂ loading, decreasing from 3.75 to 3.54 eV according to the Tauc method and from 3.70 to 3.43 eV according to the ASF method, accompanied by an increase in Urbach energy from 0.43 to 0.64 eV, indicating enhanced structural disorder and tail state formation. The optical dispersion parameters obtained from the Wemple−DiDomenico model were consistent with these trends. Electrical characterization showed enhanced DC conductivity with increasing TiO₂ content and a marked reduction in thermal activation energy from 2.54 eV for the neat blend to 0.98 eV at higher TiO₂ loading, confirming facilitated charge transport in nanocomposite system. Mechanical characterization indicated that TiO₂ reinforcement improved both stiffness and strength, with the 6 wt.% sample achieving an optimal strength–ductility synergy (8.9 MPa and 121.5% elongation). Additionally, TiO₂ loading significantly boosted antibacterial performance, particularly against Escherichia coli and Staphylococcus aureus at 8 wt.%. These multifunctional properties position PVA/PVP:TiO₂ nanofibers as highly promising candidates for flexible biomedical coatings, optoelectronic devices, and advanced functional surfaces. Full article

To address the long-standing bottleneck of inherent trade-off between thermoelectric performance and mechanical stability in pure In₂O₃ thermoelectric materials, this study puts forward a novel optimization route by innovatively adopting Yb₂O₃ as the dopant, pioneering the dual regulation of defect engineering and electronic structure reconstruction to achieve synchronous thermoelectric–mechanical property synergy, which breaks the limitation of traditional single-property doping modification for oxide thermoelectrics. For electrical transport, Yb³⁺ induces oxygen vacancy donor defects to boost carrier concentration, and targeted orbital hybridization narrows the band gap and elevates density of states near the Fermi level, synergistically lifting conductivity and offsetting the weakened Seebeck coefficient to optimize power factor with he maximum power factor improved from 1.83 μWm⁻¹K⁻² to 5.67 μWm⁻¹K⁻². For thermal transport, doping-induced lattice distortion and multi-scale defect system build intensive phonon scattering centers, sharply suppressing lattice thermal conductivity and lowering total thermal conductivity. This synergistic optimization pushes the maximum ZT value to 0.358, a remarkable breakthrough for In₂O₃-based materials. Meanwhile, Yb₂O₃ doping reinforces Vickers hardness via lattice distortion strengthening and defect bonding enhancement, eliminating the inherent performance trade-off. This work verifies Yb₂O₃ doping as a highly efficient strategy, offering solid theoretical basis and practical guidance for developing high-performance, high-stability oxide thermoelectric materials for practical applications. Full article

To address the issues that carbon trading fails to cover the full life cycle and that traditional demand response achieves poor emission reduction due to a lack of accurate carbon-intensity feedback in park integrated energy systems (PIESs) during low-carbon transition, this study proposes a two-layer optimal scheduling method synergizing life-cycle stepwise carbon trading and low-carbon demand response (LCDR) to balance low-carbon performance and economic efficiency. Firstly, based on life cycle theory, embodied carbon from new energy equipment manufacturing and transportation is incorporated into accounting, with a stepwise carbon trading mechanism designed. Secondly, corrected dynamic carbon emission factors for power and heating networks are constructed to quantify real-time carbon intensity. A dual-driven LCDR model (electricity price and carbon factor) is established to coordinate shiftable and sheddable electric-thermal loads and is combined with a two-layer scheduling model (pre-scheduling and re-scheduling) targeting the minimal total operation cost. Simulation results of a South China park show that life-cycle stepwise carbon trading reduces emissions by 16.7%, and LCDR further cuts 4.05%. Their synergy achieves significant carbon reduction with a slight cost increase, while supplementary sensitivity analyses further confirm the scalability and robustness of the proposed framework under varying load levels and demand response capabilities. Full article

The decarbonization of the residential sector is a critical component of the European Green Deal, particularly in transition economies like Poland. This study proposes a comprehensive techno-economic optimization of a deeply retrofitted single-family house aiming for net-zero energy building (NZEB) status. The research specifically focuses on the Polish coastal climate zone, characterized by distinct humidity, wind, and temperature profiles compared to inland regions, which significantly influence the efficiency of air-to-water heat pumps (ASHP). Based on a real-world energy audit, the study simulates the synergy between a deep thermal envelope upgrade and a hybrid system comprising an ASHP, photovoltaics (PV), and battery energy storage (BES). This paper presents a detailed economic analysis of such hybrid systems under the new Polish ‘net-billing’ prosumer mechanism. The study evaluates the impact of electricity tariff structures (flat-rate G11 vs. time-of-use G12w) on the investment’s profitability. By calculating key performance indicators—including the levelized cost of energy (LCOE), net present value (NPV), and self-sufficiency ratio (SSR)—the research assesses various system configurations. The initial evaluation indicates that while deep retrofitting significantly reduces heating demand, integrating battery storage plays a critical role in enhancing economic returns under the net-billing framework. The analysis demonstrates that the optimized hybrid system (9.0 kWp PV + 10 kWh BESS) achieves an average annual self-sufficiency ratio (SSR) of 49.8% and reduces the non-renewable primary energy (EP) indicator to 0.0 kWh/(m²·year). Economically, the investment yields a positive NPV of €3194, an IRR of 5.25%, and a LCOE of €0.184/kWh, which is 34% lower than projected grid prices. Furthermore, switching to a time-of-use tariff (G12w) generates an additional 11% (€139) in annual savings. These quantitative findings provide actionable guidelines for policymakers and investors, confirming the financial viability and environmental benefit (annual reduction of 6.12 MgCO₂) of NZEB standards in coastal areas. Full article

With the large-scale integration of distributed energy resources, modern energy systems are becoming increasingly dependent on communication networks for monitoring and control. This growing reliance exposes integrated energy systems (IESs) to potential cyber threats, as attackers may exploit vulnerabilities in communication protocols to disrupt system operation. However, most existing studies primarily investigate the stable operation of electro–thermal coupled systems from a defensive standpoint, while paying limited attention to the potential economic damage that could be induced from an attacker’s perspective. Motivated by this gap, this paper develops an optimal coordinated attack strategy targeting both energy storage units and load-side resources from the attacker’s viewpoint. First, an economic dispatch model for an electricity–heat–gas integrated energy system is established, and a fully distributed solution algorithm is proposed to obtain the optimal economic operating cost. Subsequently, by compromising energy storage and load units with relatively low security levels, a three-stage coordinated cyber-attack framework is designed for the IES. In the first two stages, covert data integrity attacks (DIAs) are launched to inject falsified power information into the system. In the third stage, a denial-of-service (DoS) attack is introduced to operate in synergy with the DIAs, forcing the system to converge to a feasible yet economically suboptimal operating point. The optimal initiation timing of the DoS attack is derived through theoretical analysis. Simulation results demonstrate that the proposed strategy can induce an economic loss of approximately 21.7% while maintaining system feasibility. By revealing these latent vulnerabilities from an attacker-oriented perspective, this study provides a theoretical basis for the development of proactive defense mechanisms, thereby enhancing the long-term economic and operational security of future integrated energy systems. Full article

This review systematically synthesizes technological synergies within a Community Energy System (CES), emphasizing cold-climate contexts where heating-dominant demand profiles and strong seasonality create distinct operational challenges. Drawing on 115 studies (2010–2024), the paper explores how integrated thermal, electrical, and digital infrastructures support net-zero and climate-resilient communities in regions with substantial heating requirements. Thermal–electrical coupling emerges as a foundational mechanism in cold climates, where heating loads dominate annual energy demand and drive winter peak constraints. Power-to-Heat (P2H) systems, cold-climate heat pumps, and hybrid configurations combining Thermal Energy Storage (TES) with Battery Energy Storage Systems (BESS) enable multi-timescale flexibility, allowing renewable energy to be shifted from hours to seasons. District Energy Systems (DES) act as a thermal backbone, enabling this integration across extended heating seasons and transforming thermal demand into a grid-balancing resource. Digital technologies further enhance system coordination under variable climatic conditions. Artificial Intelligence (AI), the Internet of Things (IoT), and Advanced Metering Infrastructure (AMI) support real-time optimization, demand response, and cross-vector control within Renewable Energy Communities (RECs) and Virtual Power Plants (VPPs). At the system level, decentralized architectures—including microgrids, Non-Wire Alternatives (NWAs), and peer-to-peer (P2P) trading—strengthen resilience by maintaining thermal and electrical continuity during grid disruptions. Building on these findings, the review synthesizes cross-cutting technological synergies and proposes deployment pathways tailored to cold-climate CES, supported by comparative case studies. Despite demonstrated benefits, widespread adoption remains constrained by high upfront costs, interoperability challenges, and fragmented regulatory frameworks. The review concludes with policy, governance, and research recommendations to enable scalable, equitable, and climate-responsive CES deployment in heating-dominated regions. Full article

Urban heat islands (UHIs) increase the cooling load and reduce the performance of rooftop photovoltaic (PV) systems; thus, the co-benefits of integrating bio-solar green roofs require quantification and real-world demonstration to encourage the uptake of this technology. Consequently, this study compares the thermal and electrical performances of four simultaneously installed roof assemblies, namely conventional roof (CR), green roof (GR), photovoltaic roof (pCR), and bio-solar green roof (pGR), under clear-sky summer periods in Lahore, Pakistan. The experiment equipped the same insulated test cells with meteorological, thermal, moisture, and PV power gauging to collect data every 1 min; standardized layers were built, and the PV tilt was set to 22°. The results show that pGR always performs better compared with other roof assemblies: the temperature on the outer surface is lower, the diurnal amplitude is the most reduced (ΔDF ≈ +19% vs. CR), the thermal response is the most delayed (ΔTL ≈ −21%), and TPI improves by 6.5–7%. All of these results indicate a new, field-validated synergy between evapotranspiration and PV shading/ventilation that could translate into practical value through reduced peak cooling loads (demand control), lower day-to-day cooling energy, and incremental PV gains. These are critical factors for achieving positive techno-economic outcomes in hot, sunny cities, with the aim of realizing UHI mitigation and resilient building energy systems. Full article

This study investigates the role of biogas and biomethane in accelerating the decarbonization of district heating systems in Europe. A structured literature review combined with two representative case studies evaluate technological, economic, and environmental performance across different system scales. The Meppel optimization model developed for the Netherlands and the large-scale Backbone energy system modelling framework for Finland are compared to identify methodological synergies and operational insights for integrating bioenergy into heating networks. The results show that biogas-based combined heat and power systems can reduce carbon dioxide emissions by more than 70 percent compared with fossil-based alternatives and significantly improve local energy security, especially when coupled with heat pumps and thermal storage. Large-scale modelling further demonstrates that biomethane and bioenergy resources provide valuable system flexibility, facilitating sector coupling and supporting the balancing of variable renewable electricity production. This study’s main contribution is an integrated comparative assessment at two different scales (local and regional), linking operational data, modelling, and performance results to determine how biogas and biomethane can optimize the energy system in the short and long term for centralized heat supply. The findings confirm that biogas and biomethane are essential, dispatchable renewable resources capable of supporting scalable, low-carbon, and resilient district heating systems across Europe. Full article

The advancement of smart packaging technology demands high-performance and sustainable sensing materials. While starch is a biodegradable natural polymer, its inherent high crystallinity restricts charge transport capability. This study developed a novel smart sensing film by incorporating ellagic acid-derived blue, fluorescent carbon dots (CDs) into phosphate starch (PS), which is rich in phosphorus. The effects of silver ions (Ag⁺), sodium carboxymethyl cellulose (CMC), and CDs on the film properties were systematically investigated. Results indicate that CDs act as flexible nano-crosslinkers, forming hydrogen bonds with PS molecular chains and effectively balancing strength and toughness—achieving a tensile strength of 5.1 MPa and an elongation at break of 24.1%. Phosphorus, in synergy with CDs, facilitates an efficient dual conduction pathway for ions and electrons: phosphate groups enable ion transport, while the conjugated carbon cores of the CDs provide electron transport channels. This synergistic effect significantly reduces the film’s electrical impedance from 6.93 × 10⁶ Ω to 1.12 × 10⁶ Ω (a reduction of 84%) and enhances thermal stability, increasing the char residue from 1.1% to 18.3%. The PS/CDs composite film exhibits a strong linear current response to pH in the range of 2–7 (R² = 0.9450), and shows enhanced discrimination between fresh orange juice (pH = 3.38) and spoiled orange juice (pH = 2.68), with a current change of 0.62 × 10⁻⁵ A. Moreover, the film exhibits strong blue fluorescence at 427 nm, with an intensity that shows a pronounced pH-dependent response. This study elucidates the mechanism by which phosphorus and CDs synergistically enhance the sensing performance of starch-based films, offering a new strategy for developing high-performance starch-based materials for smart packaging. Full article

Hybrid electric vehicles (HEVs) frequently cycle their internal combustion engines (ICE), potentially cooling the three-way catalyst (TWC). This challenges the use of compressed natural gas (CNG), as methane (CH₄) requires high temperatures for TWC oxidation. This study experimentally investigates the performance, engine-out emissions (CO, NO_x, CH₄, NMHC, CO₂), and catalyst temperatures of a Toyota RAV4 hybrid vehicle on gasoline (G), CNG, and dual fuel (MIX) during the WLTC. Engine-out emissions were measured upstream of the TWC. Results showed similar engine work output (~17.8 kWh/100 km), while CNG significantly reduced fuel mass consumption (−18.7%) and CO₂ emissions (−27.5%) compared to gasoline, driven by both its higher LHV and higher average BTE. CO (−32.3%) and NO_x (−34.0%) emissions were lower with CNG, linked to leaner operation and significantly retarded ignition timing for NO_x control. However, CH₄ emissions drastically increased with CNG. This study reveals a synergy between the same retarded ignition timing strategy used to successfully control engine-out NO_x (−34.0%) and created a positive secondary effect, raising pre-TWC temperatures by 4.5%. Higher thermal condition is essential for the aftertreatment of chemically stable methane, highlighting a direct link between the engine’s NO_x control logic and the potential to mitigate methane slip. Full article

The rapid advancement of technologies such as artificial intelligence, big data, and cloud computing has driven continuous expansion of global data centers, resulting in increasingly severe energy consumption and carbon emission challenges. According to projections by the International Energy Agency (IEA), the global electricity demand of data centers is expected to double by 2030. The construction of green data centers has emerged as a critical pathway for achieving carbon neutrality goals and facilitating energy structure transition. This paper presents a systematic review of the role of waste heat recovery technologies in data centers for achieving low-carbon development. Categorized by aspects of waste heat recovery technologies, power production and district heating, it focuses on assessing the applicability of heat collection technologies, such as heat pumps, thermal energy storage and absorption cooling, in different scenarios. This study examines multiple electricity generation pathways, specifically the Organic Rankine Cycle (ORC), Kalina Cycle (KC), and thermoelectric generators (TEG), with comprehensive analysis of their technical performance and economic viability. The study also assesses the feasibility and environmental advantages of using data center waste heat for district heating. This application, supported by heat pumps and thermal energy storage, could serve both residential and industrial areas. The study shows that waste heat recovery technologies can not only significantly reduce the Power Usage Effectiveness (PUE) of data centers, but also deliver substantial economic returns and emission reduction potential. In the future, the integration of green computing power with renewable energy will emerge as the cornerstone of sustainable data center development. Through intelligent energy management systems, cascaded energy utilization and regional energy synergy, data centers are poised to transition from traditional “energy-intensive facilities” to proactive “clean energy collaborators” within the smart grid ecosystem. Full article