Search Results (201)

Hybridization of solar and wind energy sources is a promising solution to enhance the dispatch capability of renewables. The complementarity of wind and solar radiation, as well as the sharing of transmission lines and other infrastructures, can notably benefit the deployment of renewable power. Mapping of hybrid solar–wind potential can help identify new emplacements or existing power facilities where an extension with a hybrid system might work. This paper presents an analysis of a hybrid solar–wind potential by considering a reference power plant of 40 MW in the Iberian Peninsula and comparing the hybrid and non-hybrid energy generated. The generation of energy is estimated using SAM for a typical meteorological year, using PVGIS and ERA5 meteorological information as input. Modeling the hybrid plant in relation to individual PV and wind power plants minimizes the dependence on technical and economic input data, allowing for the expression of potential hybridization analysis in relative numbers through maps. Correlation coefficient and capacity factor maps are presented here at different time scales, showing the complementarity in most of the spatial domain. In addition, economic analysis in comparison with non-hybrid power plants shows a reduction of around 25–30% in the LCOE in many areas of interest. Finally, a sizing sensitivity analysis is also performed to select the most beneficial sharing between PV and wind. Full article

To advance evidence-based urban design prioritizing non-motorized mobility, this study proposes a street view-enabled explainable machine learning framework that systematically links built environment semantics to non-motorized transportation vitality optimization. By integrating Baidu Street View images with deep learning-based object detection (Faster R-CNN), we quantify fine-grained human-powered and mechanically assisted mobility vitality. These features are fused with multi-source geospatial data encompassing 23 built environment variables into an interpretable machine learning pipeline using SHAP-optimized random forest models. The key findings reveal distinct nonlinear response patterns between HP and MA modes to built environment factors; for instance, a notable promotion in mechanically assisted NMT vitality is observed as enterprise density increases beyond 0.2 facilities per ha. Emergent synergistic and threshold effects are evident from variable interactions requiring multidimensional planning consideration, as demonstrated in phenomena such as the peaking of human-powered NMT vitality occurring at public facility densities of 0.2–0.8 facilities per ha, enterprise densities of 0.6–1 facilities per ha, and spatial heterogeneity patterns identified through Bivariate Local Moran’s I clustering. This research contributes an innovative technical framework combining street view image recognition with explainable AI, while practically informing urban planning through evidence-based mobility zone classification and targeted strategy formulation, enabling more precise optimization of pedestrian-/cyclist-oriented urban spaces. Full article

The combustion of hard coal and lignite in power and combined heat and power plants generates significant amounts of coal fly ash (CFA), a waste material with variable properties. CFA naturally contains radionuclides, specifically naturally occurring radioactive materials (NORMs), which pose potential radiological risks to the environment and human health during their storage and utilization, including their incorporation into building materials. Although global research on the radionuclide content in CFA is available, there is a clear gap in detailed and current data specific to Central and Eastern Europe and notably, a lack of a systematic analysis investigating the influence of installed power plant capacity on the concentration profile of these radionuclides in the generated ash. This study aimed to fill this gap and provide crucial data for the Polish energy and environmental context. The objective was to evaluate the concentrations of selected radionuclides (²³²Th, ²²⁶Ra, and ⁴⁰K) in coal fly ash samples collected between 2020 and 2023 from 19 Polish power and combined heat and power plants with varying capacities (categorized into four groups: S1–S4) and to assess the associated radiological risk. Radionuclide concentrations were determined using gamma spectrometry, and differences between groups were analyzed using non-parametric statistical methods, including PERMANOVA. The results demonstrated that plant capacity has a statistically significant influence on the concentration profiles of thorium and potassium but not radium. Calculated radiological hazard assessment factors (Ra_eq, H_ex, H_in, IAED) revealed that although most samples fall near regulatory limits (e.g., 370 Bq kg⁻¹ for Ra_eq), some exceed these limits, particularly in groups S1 (plants with a capacity less than 300 MW) and S4 (plants with a capacity higher than 300 MW). It was also found that the frequency of exceeding the annual effective dose limits (IAEDs) showed an increasing trend with the increasing installed capacity of the facility. These findings underscore the importance of plant capacity as a key factor to consider in the radiological risk assessment associated with coal fly ash. This study’s outcomes are crucial for informing environmental risk management strategies, guiding safe waste processing practices, and shaping environmental policies within the energy sector in Central and Eastern European countries, including Poland. Full article

Background/Objectives: The role of the vitreous in the effective lens position (ELP) is controversial in patients undergoing phacovitrectomy. The aim of this study was to compare the change in aqueous depth (AD), a surrogate of the ELP, in non-vitrectomized and vitrectomized fellow eyes. Methods: Post-hoc analysis of a prospective study conducted in OMIQ facilities (Barcelona, Spain) between 2021 and 2023. Patients with bilateral cataracts and a unilateral grade 2/3 epiretinal membrane underwent phacoemulsification in one eye and phacovitrectomy without endotamponade in the fellow eye. All eyes were implanted with an extended depth-of-focus intraocular lens after power calculation using the same biometer, technicians, formula, and surgeon. We compared the change in AD (mm and percentage) from baseline, and the role of vitrectomy without endotamponade on AD with a mixed-effects models. Results: We included 40 eyes (20 patients) with a mean age of 71.6 years, with 55% females. The mean change in AD was +1.51 (vitrectomized) and +1.42 mm (non-vitrectomized eyes), p = 0.33. The percent of change in AD was not different between groups (p ≥ 0.38) and phacovitrectomy had no effect on the change in AD on mixed-effects models (p > 0.10). Conclusions: The absence of the vitreous had a minimal influence on AD in these patients undergoing standard phacoemulsification or phacovitrectomy. Full article

High-repetition-rate targets present an opportunity for developing diagnostic tools for on-demand calibration at high-power laser facilities for consistent performance and reproducibility during experimental campaigns. The non-linear change in transmission associated with a laser-driven plasma mirror, based on high-repetition rate targets, has been used in a Frequency Resolved Optical Gating (FROG) configuration to analyze the spectral phase for near-infrared pulses far from the Fourier limit. Three types of targets were compared for characterizing pulses in the 1–8 ps range: a glass slide, a polymer tape, and a thin liquid sheet created by two impinging micrometer-scale jets. The thin liquid film had the best mechanical stability and introduced the least spectral distortion, allowing the most robust reconstruction of the temporal intensity profile. The spectral phase was reconstructed using a non-iterative algorithm, which reproduced the second-order phase distortions induced with an acousto-optic programmable dispersive filter with an RMS error of 6.2%, leading to measured pulse durations with an RMS deviation ranging from 1% for pulses of 6.8–7.8 ps up to 7.5% for pulses around 1 ps. Full article

With global efforts intensifying towards achieving carbon neutrality, accurately monitoring and managing energy consumption in industrial sectors has become critical. Non-Intrusive Load Monitoring (NILM) technology presents a cost-effective solution for industrial energy management by decomposing aggregate power data into individual device-level information without extensive hardware requirements. However, existing NILM methods primarily tailored for residential applications struggle to capture complex inter-device correlations and production-dependent load dynamics prevalent in industrial environments, such as cement plants. This paper proposes a novel sequence-to-sequence-based non-intrusive load disaggregation method that integrates Convolutional Neural Networks (CNN) and Transformer architectures, specifically addressing the challenges of multi-device load disaggregation in industrial settings. An innovative time–application attention mechanism was integrated to effectively model long-term temporal dependencies and the collaborative operational relationships between industrial devices. Additionally, global constraints—including consistency, smoothness, and sparsity—were introduced into the loss function to ensure power conservation, reduce noise, and achieve precise zero-power predictions for inactive equipment. The proposed method was validated on real-world power consumption data collected from a cement production facility. Experimental results indicate that the proposed method significantly outperforms traditional NILM approaches with average improvements of 4.98%, 3.70%, and 4.38% in terms of accuracy, recall, and F1-score, respectively. These findings underscore its superior robustness in noisy conditions and under device fault conditions, further affirming its applicability and potential for deployment in industrial settings. Full article

Low carbon dioxide (CO₂) emissions make nuclear energy crucial in decarbonizing the economy. In this context, nuclear safety, and especially the operation of nuclear power plants, remains a critical issue. This article presents a new fractal cluster method of control that improves the quality of assessing fuel element cladding integrity, which is critical for nuclear and environmental safety. The proposed non-destructive testing method allows for detecting defects on the inner and outer cladding surfaces without removing the elements from the nuclear reactor, which ensures prompt response and prevention of radiation leakage. Studies have shown that the fractal dimension of the cladding surface, which varies from 2.1 to 2.5, indicates significant heterogeneity caused by mechanical damage or corrosion, which can affect its integrity. The density analysis of defect clusters allows quantifying their concentration per unit area, which is an important indicator for assessing the risks associated with the operation of nuclear facilities. The data obtained are used to assess the impact of defects on the vessel’s integrity and, in turn, on nuclear safety. The monitoring results are transmitted in real time to the operator’s automated workstation, allowing for timely decision making to prevent radioactive releases and improve environmental safety. The proposed method is a promising tool for ensuring reliable quality control of the fuel element cladding condition and improving nuclear and environmental safety. While the study is based on VVER-1000 reactor data, the flexibility of the proposed methodology suggests its potential applicability to other reactor types, opening avenues for broader implementation in diverse nuclear systems. Full article

E-methane is considered the most important way to decarbonize the natural gas system in Japan. The advantage of e-methane is that it can use existing natural gas infrastructure and end-use facilities. There is a potential for China to produce e-methane and export it to Japan in the future. Therefore, the greenhouse gas (GHG) emissions and economic analysis of e-methane should be studied in both countries. The GHG emissions of e-methane are 0.927 kg-CO₂e per kg e-methane if all processes are powered by solar energy. The largest portion of GHG emissions from e-methane comes from hydrogen, which comprises more than 85% if solar energy is used for all processes. When solar energy is used to produce hydrogen, but grid electricity is used for other processes, the GHG emissions exceed the Europe Union’s Renewable Liquid and Gaseous Transport Fuels of Non-Biological Origin (RFNBO) requirements, whether in Japan or in China. The levelized cost of e-methane produced in Japan is much higher than in China. The levelized cost of e-methane in Japan is 4489 USD/ton in the base case (2021), 2842 USD/ton in the 2030 case, and 1674 USD/ton in the 2050 case. In China, it is 2450 USD/ton, 1505 USD/ton, and 1082 USD/ton, respectively. The cost of hydrogen is the largest contributor to the levelized cost of e-methane, accounting for more than 60% in all cases. For China and Japan to cooperate in the value chain of e-methane, a carbon accounting mechanism and a carbon pricing mechanism mutually recognized by both Japan and China are necessary. Full article

Bulk heterojunction (BHJ) organic solar cells (OSCs) represent a promising technology due to their cost-effectiveness, lightweight design and potential for flexible manufacturing. However, achieving a high power conversion efficiency (PCE) and long-term stability necessitates optimizing the interfacial layers. Zinc oxide (ZnO), commonly used as an electron extraction layer (EEL) in inverted OSCs, suffers from surface defects that hinder device performance. Furthermore, the active control of its optoelectronic properties is highly desirable as the interfacial electron transport and extraction, exciton dissociation and non-radiative recombination are crucial for optimum solar cell operation. In this regard, this study investigates the sulfur doping of ZnO as a facile method to effectively increase ZnO conductivity, improve the interfacial electron transfer and, overall, enhance solar cell performance. ZnO films were sulfur-treated under various annealing temperatures, with the optimal condition found at 250 °C. Devices incorporating sulfur-doped ZnO (S-ZnO) exhibited a significant PCE improvement from 2.11% for the device with the pristine ZnO to 3.14% for the OSC based on the S-ZnO annealed at 250 °C, attributed to an enhanced short-circuit current density (J_sc) and fill factor (FF). Optical and structural analyses revealed that the sulfur treatment led to a small enhancement of the ZnO film crystallite size and an increased n-type transport capability. Additionally, the sulfurization of ZnO enhanced its electron extraction efficiency, exciton dissociation at the ZnO/photoactive layer interface and exciton/charge generation rate without altering the film morphology. These findings highlight the potential of sulfur doping as an easily implemented, straightforward approach to improving the performance of inverted OSCs. Full article

In response to the challenges of imbalanced economic efficiency of charging stations caused by disorderly charging of large-scale electric vehicles (EVs), rising electricity expenditure of users, and increased risk of stable operation of the power grid, this study designs a user-side vehicle pile resource interaction strategy considering source load clustering to enhance the economy and safety of electric vehicle energy management. Firstly, by constructing a dynamic traffic flow distribution network coupling architecture, a bidirectional interaction model between charging facilities and transportation/power systems is established to analyze the dynamic correlation between charging demand and road network status. Next, an EV charging and discharging electricity price response model is established to quantify the load regulation potential under different scenarios. Secondly, by combining urban transportation big data and prediction networks, high-precision inference of the spatiotemporal distribution of charging loads can be achieved. Then, a multidimensional optimization objective function covering operator revenue, user economy, and grid power quality is constructed, and a collaborative decision-making model is established. Finally, the IEEE69 node system is validated through joint simulation with actual urban areas, and the non-dominated sorting genetic algorithm II (NSGA-II) based on reference points is used for the solution. The results show that the optimization strategy proposed by NSGA-II can increase the operating revenue of charging stations by 33.43% while reducing user energy costs and grid voltage deviations by 18.9% and 68.89%, respectively. Full article

Background: Burns represent one of the most severe injuries encountered in the pre-hospital and ED environment, with essential features and an often negatively powerful impact on patients’ quality of life. Preventive measures can significantly reduce the number of cases presenting to medical facilities; knowledge and the correct application of first aid measures in the pre-hospital stage have a significant role in reducing the risk of complications and in obtaining optimal outcomes. Methods: This retrospective one-year single-center study analyzed 399 adult burn patients treated at the Clinical Emergency Hospital of Bucharest (CEHB) in 2023. Information concerning the main characteristics of the patients (age, sex, and residence), etiology and severity of burns, and pre-hospital management of patients was analyzed. Results: Most patients (63.41%) resided in urban areas, with a higher prevalence of males (55.89%). Thermal burns accounted for 77.69% of cases, primarily caused by water, food, oil, or flames. Burns covered ≤10% TBSA in 77.19% of cases, while 6.52% extended beyond 50% TBSA. First aid was provided to 52.63% of patients at the accident site, often by non-specialized individuals. The mean time to presentation was 34.90 h, with significant correlations between time, age, burned body surface area, and burn depth. Conclusions: There is a real need for improvements in first-aid training and health initiatives to enhance pre-hospital burn care. Better documentation of the care provided to patients before being admitted to specialized centers, as well as further studies in this field, are absolutely necessary for improving prevention programs and burn management in the acute stage. Full article

Every year, electric power systems (EPSs) experience accidents resulting in static and dynamic instability, as well as power supply disruptions. Accidents evolve along various trajectories and sometimes can exhibit a cascading effect. In this case, the sequential tripping of generating and/or electric network equipment occurs due to overloads or voltage drops at various nodes of the electric network. This leads to significant losses for industrial and commercial consumers, while also escalating social tensions within the population. This study aims to develop an algorithm for revealing the possibility of cascading failure processes in EPSs and their development trajectories. The use of the algorithm in planning and managing power flows in EPSs facilitates the identification of the boundary between the regions of admissible and inadmissible post-contingency power flows. The algorithm also enables the assessment of the impact of various topology solutions and operational measures on the development of cascading failure processes. This paper presents the results of steady-state calculation for the test schemes of an EPS incorporating 25, 36, and 40 nodes with voltage levels of 6, 35, 110, and 500 kV to illustrate the influence of topology and the non-homogeneity of network parameters on the occurrence and development of cascading failure processes. The deployment of distributed generation facilities of different capacities and FACTS devices, alongside the redistribution of power flows in the network by changing the load of power plants with different electricity generation costs, are considered topology and operational measures that enhance the survivability of the EPS. The performance of the developed algorithm was illustrated through an analysis of the process of the development of a real cascading systemic accident that occurred in the EPS. The proposed algorithm, when utilized in planning and managing power flows in an EPS, facilitates the identification of possibilities for the cascading failure processes and their development pathways to subsequently design and implement the operational measures and topological adjustments to prevent them. Full article

Memristors are promising candidates for next-generation non-volatile memory devices, offering low power consumption and high-speed switching capabilities. However, conventional metal oxide-based memristors are constrained by fabrication complexity and high costs, limiting their commercial viability. Organic–inorganic hybrid perovskites (OIHPs), known for their facile solution processability and unique ionic–electronic conductivity, provide an attractive alternative. This study presents a conjugated polyelectrolyte (CPE), PhNa-1T, as an interlayer for OIHP memristors to enhance the high-resistance state (HRS) performance. A post-treatment process using n-octylammonium bromide (OABr) was further applied to optimize the interlayer properties. Devices treated with PhNa-1T/OABr achieved a significantly improved ON/OFF ratio of 2150, compared to 197 for untreated devices. Systematic characterization revealed that OABr treatment improved film morphology, reduced crystallite strain, and optimized energy level alignment, thereby reinforcing the Schottky barrier and minimizing current leakage. These findings highlight the potential of tailored interlayer engineering to improve OIHP-based memristor performance, offering promising prospects for applications in non-volatile memory technologies. Full article

Industrial process heat typically requires large amounts of fossil fuels. Solar energy, while abundant and free, has low energy density, and so large collector areas are needed to meet thermal needs. Land costs in developed areas are often prohibitively high, making rooftop-based concentrating solar power (CSP) attractive. However, limited rooftop space and the low energy density of solar power are usually insufficient to meet a facility’s demands. Maximizing annual CSP energy generation within a bounded rooftop space is necessary to mitigate fossil fuel consumption. This is a different optimization objective than minimizing the Levelized Cost of Energy (LCOE) in typical open-land, utility-scale heliostat layout optimization. Innovative designs are necessary, such as compact, energy-dense central receiver systems with non-flat heliostat field topographies that use spatially efficient Tilt–Roll heliostats or multi-rooftop and multi-height distributed urban systems. A novel ray-tracing simulation tool was developed to evaluate these unique scenarios. For compact systems, optimized annual energy production occurred with maximum heliostat spatial density, and the best non-flat heliostat field topography found is a shallow section of a parabolic cylinder with an East–West focal axis, yielding a 10% optical energy improvement. Tightly packed Tilt–Roll heliostats showed a double improvement in optical energy at the receiver compared to Azimuth–Elevation heliostats. Full article

Spent nuclear fuel (SNF) from the United States’ nuclear power plants has been placed in dry cask storage systems since the 1980s. Due to the lack of a clear path for permanent geological repository for SNF, consolidated and long-term storage solutions that use durable concrete and avoid current aging and licensing challenges are becoming indispensable. Ultra-high-performance concrete (UHPC) is a rapidly growing advanced concrete solution with superior mechanical and durability properties that can help realize future resilient nuclear storage facilities. Thus, the overall goal of this review study is to demonstrate the viability of UHPC as a long-term solution for future nuclear storage facilities. The paper first identifies all possible non-nuclear (environmental) and nuclear (thermal and radiation-induced) degradation mechanisms in concrete overpacks and storage modules with critical assessment and projections on UHPC performance in comparison to current conventional concrete solutions. Next, since concrete serves as a shielding material in nuclear settings, the preliminary attenuation properties of UHPC from emerging studies are synthesized along with the possible mix modifications to improve its attenuation performance. The paper identifies the major knowledge gaps to inform future research and development, aimed at rethinking the design of SNF dry storage facilities by incorporating UHPC. Full article