Search Results (9,757)

Particle size distributions produced during comminution are widely correlated with gold flotation performance, yet their interpretation as intrinsic particle characteristics is often confounded by particle generation mechanisms. This study applies a structural causal modelling framework to a controlled legacy flotation dataset (N = 11) generated using Vertical Shaft Impact (VSI) and High-Pressure Grinding Rolls (HPGRs) to distinguish particle size-mediated effects from non-size-mediated comminution effects. Structural decomposition showed that LS-HPGR exhibited a total recovery advantage of +8.60 percentage points relative to VSI, comprising a positive direct effect of +18.98 percentage points partially offset by a negative particle size-mediated effect of −10.37 percentage points. Counterfactual analysis confirmed that crusher-specific flotation responses persisted even under comparable particle size distributions. Crusher-specific effects were further interpreted in the context of measured comminution power and processing-time data. Particle size significantly influenced concentrate grade (p = 0.002) but showed only weak influence on recovery within the tested operating range. These findings demonstrate that particle size distributions function as mediating particle-scale properties rather than purely descriptive metrics, extending flotation process interpretation beyond conventional size–performance correlations. Full article

Large Language Models (LLMs) offer opportunities for processing heterogeneous information streams relevant to energy-market decision-making, but their practical role in forecasting-oriented analytical workflows remains uncertain. This paper presents an exploratory feasibility study of LLM use across four energy-market tasks: geopolitical event monitoring for Dutch Title Transfer Facility (TTF) market context using Global Database of Events, Language, and Tone (GDELT)-based data, structured summarisation of commodity-intelligence articles, prompt-engineered solar-power and grid-load forecasting for Austria, and a short-horizon exploratory TTF price-estimation case. The study is positioned as a pilot investigation and hybrid workflow blueprint rather than as a statistically conclusive forecasting benchmark. A four-layer reference architecture was devised, including structured market data, semi-structured news intelligence, web-scraping concepts, and implemented Twitter/X and GDELT monitoring layers. The empirical cases indicate that LLMs are most useful for text-heavy reasoning, event-context integration, source triage, and structured interpretation. In the 20-article summarisation corpus, Gemini 1.5 Pro achieved higher commodity-direction accuracy than GPT-4, while GPT-4 showed stronger output-format stability. In selected solar case checks, OpenAI models produced plausible generation curves close to the Fraunhofer ISE Energy Charts reference, while Energy Charts remained more accurate for aggregate load estimation in the available benchmark comparison. The two-day TTF experiment illustrated that LLMs can incorporate qualitative geopolitical context into short-horizon reasoning, but it did not establish reliable price-forecasting capability. The Twitter/X monitoring layer is retained as a documented negative pathway, showing the limitations of informal social-media scraping for reproducible market intelligence. Full article

This work demonstrated improvements in the photovoltaic performance metrics of a dye-sensitized solar cell (DSSC) through the application of Eu-doped strontium silicate (Sr₂SiO₄:Eu³⁺), a luminescent downshifting (LDS) material. The material converted underutilized high-energy ultraviolet (UV) photons into lower-energy visible photons for better spectral responsivity in the DSSC. A conventional solid-state technique was applied in the synthesis of the material. Surface morphology was examined by scanning electron microscopy (SEM). Photoluminescence (PL) measurements were conducted to analyze fluorescence emission. The photovoltaic performances of the bare and LDS-enhanced devices were analyzed using photovoltaic current–voltage measurements. Compared to the bare DSSC, the cell containing Sr₂SiO₄:Eu³⁺ LDS phosphor material had an enhancement of 14.8% in the short-circuit current density (J_sc), from 0.243–0.279 mA/cm². The open-circuit voltage (V_oc) yielded an improvement of 10% from 580–638 mV. Maximum power output (P_max) produced a boost of 26.5% from 0.0136–0.0172 mW and the efficiency improvement at 26.6% from 1.09–1.38%. The coefficient of variation was introduced to evaluate device reproducibility. The device with the incorporation of Sr₂SiO₄:Eu³⁺ LDS phosphor depicted a coefficient of variation of 8.5%, suggesting good DSSC reproducibility. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent micropollutants whose carbon–fluorine bonds resist conventional advanced oxidation. Nonthermal plasmas have emerged as a promising option for PFAS degradation, but the relative contributions of reactive oxygen species (ROS) and electrons are still being investigated. Herein, we compared sinusoidal alternating-current (AC) and nanosecond-pulsed discharges―in an identical plasma reactor with the same input power (30 W)―through diagnostics including voltage–current characterization, optical emission spectroscopy with vibrational and rotational temperatures and Hα Stark broadening for electron density, and aqueous H₂O₂ quantification. AC discharges produced more aqueous H₂O₂, stronger ·OH emission, and higher vibrational and rotational temperatures, yet showed lower perfluorooctanoic acid (PFOA) removal (85% ± 2%) and lower defluorination (61% ± 1%) than the pulsed discharge (96% ± 2% and 80% ± 2%, respectively). Among the diagnostics examined, electron density tracked the removal trend, being higher under pulsed operation (1.2 × 10¹⁶ vs. 8.3 × 10¹⁵ under AC operation). A pseudo-first-order kinetic model based on electron density qualitatively reproduced the observed PFOA decay rate, suggesting that the waveform may serve as a design variable for tuning electron and ROS-mediated pathways in plasma–water reactors. Full article

Dual beam laser welding of UNS S32750 superduplex stainless steel was performed to investigate the effect of beam-power distribution on microstructure and mechanical properties. Plates with a thickness of 3 mm were welded at a constant total power and travel speed using leading and lagging power splits of 50:50, 80:20, and 65:35. The heat affected zone width was metallographically estimated at approximately 100 µm for all conditions, consistent with comparable gross thermal exposure under constant nominal linear energy input (P_total/v). A slight modification to the power distribution altered the solidification texture and austenite morphology. The 50:50 configuration produced a refined ferritic matrix with a continuous network of grain boundaries, Widmanstätten, and intragranular acicular austenite. The 80:20 condition increased ferrite path continuity, while the 65:35 split produced an intermediate morphology. Vickers hardness reached a maximum for the 80:20 split (HAZ: 345 HV; weld metal: 349 HV). Ultimate tensile strength remained statistically constant between 908 MPa and 914 MPa, whereas elongation decreased from 28% at 50:50 to 24% at 80:20 and 23% at 65:35. All welds exhibited ductile fracture with microvoid coalescence, and electrochemical performance was comparable, with critical pitting temperature values between 78 °C and 91 °C. Beam power distribution primarily affects solidification morphology and enables control of the hardness-to-ductility balance, with a 50:50 split providing the most favorable combination of properties. Full article

The rapid growth of electric mobility is reshaping active distribution networks (ADNs), where electric vehicle charging stations (EVCS) introduce spatially concentrated, time-dependent, and highly simultaneous demand. This paper develops a network-oriented framework to evaluate EVCS integration in ADNs by coupling Colombian EV demand characterization, photovoltaic (PV) generation, battery energy storage system (BESS) operation, and AC power flow feasibility. The framework is applied to a 33-bus distribution feeder through four EVCS deployment cases and three support architectures: PV-only, PV–BESS colocated, and PV–BESS dispersed operation. The results show that non-coordinated EVCS deployment may increase losses, reduce voltage margins, and produce thermal overloads when feeder electrical sensitivity is ignored. They also reveal that optimized EVCS siting is insufficient under PV-only support, since PV generation lacks the controllability required to reshape feeder power flows during charging peaks. By contrast, BESS-assisted architectures substantially improve feeder operation, with dispersed storage achieving the best performance by decoupling charging demand locations from grid support locations. SOC and SOH analyses further demonstrate that storage feasibility and degradation must be assessed together with voltage, loading, and loss indicators. The proposed framework provides an operationally consistent basis for technically feasible EVCS planning in ADNs, linking local EV demand characterization, AC feasibility, support-architecture selection, and battery lifetime assessment. Full article

China is the world’s largest producer of hydrogen, and it has the potential to export renewable hydrogen and its derivatives. Japan has set ambitious targets for developing a hydrogen-based society but is facing cost challenges. There is strong potential for China and Japan to cooperate regarding renewable hydrogen across the value chain. This study evaluates the cooperation opportunities from the 3E perspective (energy security, economics, and the environment). It estimates the renewable hydrogen production potential in both countries, as well as the economics and greenhouse gas (GHG) emissions associated with the production and export of renewable hydrogen from China to Japan using proton exchange membrane (PEM) technology. The renewable hydrogen production potential in China is estimated to be 12.00 Mt/year by 2035 in the base case of this study, providing a strong foundation for exports to Japan. The levelized cost of hydrogen (LCOH) using PEM technology and onshore wind is estimated at 4.27 USD/kg H₂ in China and 11.01 USD/kg H₂ in Japan for projects built in 2025. Even after accounting for liquefaction costs in China, transport costs from China to Japan (Chifeng—Dalian—Kobe) and regasification costs in Japan, renewable hydrogen produced in China remains more cost-effective than that produced in Japan. In terms of GHG emissions, when renewable hydrogen is produced using wind power, and wind power is also used for liquefaction and other electricity-consuming processes, the total emissions within the case study boundary amount to 2.24 kg CO₂-eq/kg H₂, below Japan’s low-carbon hydrogen threshold of 3.4 CO₂-eq/kg H₂. This study also discusses the challenges which are critical to facilitating cooperation, particularly in regards to coordinating standards and certification systems between the two countries. Full article

Cu is widely employed in power device packaging materials owing to its excellent electrical and thermal conductivity, coupled with economic viability. Sintered Cu currently stands as one of the representative interconnect materials in power device packaging. However, it is prone to oxidation during bonding, requires extended bonding times, and needs considerable pressure. Transient liquid phase bonding (TLPB) technology is regarded as a viable solution for power device packaging, enabling high-melting-point, high-strength, and thermally stable connections at low temperatures. Cu and Sn are widely employed metallic materials in common TLP systems. The Sn-coated Cu particle increases the effective reaction area between Cu and Sn, accelerating the formation of intermetallic compounds (IMCs) and reducing bonding time. Sn-coated Cu particles were produced in this study by chemically plating Sn onto micron-sized Cu powder surfaces. The effects of flux content, bonding time, and applied pressure on joint shear strength were investigated. Results indicate that as flux content increases, the shear strength of the solder joints initially increases and then decreases. The shear strength of the solder joint gradually decreased with increasing bonding time, but no significant change was observed when the time exceeded 20 min. Increasing the applied pressure significantly enhanced the shear strength of the solder joint. The shear strength of the solder joint at 10 MPa is 90.2% higher than at 5 MPa. Full article

Background/Objectives: Cortical spreading depolarization (SD) is recognized as the pathophysiological substrate of migraine aura. Suppression of ongoing cortical activity produced by SD is thought to underlie the transient neurological deficits characteristic of the aura phase. While cortical hyperexcitability is a well-established feature of migraine brain, the effect of SD on spontaneous electrical activity in the hyperexcitable cortex remains poorly understood. Here, we investigate how SD and SD-induced depression of cortical activity are modulated by a state of mildly enhanced excitability. Methods: Using freely behaving rats, we assessed characteristics of SDs, electrocorticographic spectral power in the frontal and occipital cortices during interictal period and after SD initiation, under both drug-free conditions and following mild pharmacological disinhibition. Results: Mild cortical disinhibition resulted in a significant increase in baseline oscillatory power relative to control conditions. While cortical hyperexcitability did not alter the properties of SD itself, it differentially modulated the impact of SD on spontaneous activity in a region-specific manner. Notably, under conditions of enhanced excitability, the duration of SD-induced depression was markedly reduced in the frontal cortex but prolonged in the occipital cortex. Conclusions: These findings demonstrate that the effects of SD on spontaneous cortical activity are critically dependent on the baseline level of cortical excitability and exhibit distinct regional heterogeneity. In the awake, hyperexcitable state, the occipital cortex shows heightened vulnerability to SD-induced depression, a finding that may provide a mechanistic basis for the disproportionate involvement of the occipital cortex in aura generation and the predominance of visual symptoms in migraine aura. Full article

The rapid growth of prosumer photovoltaic installations has introduced significant supply–demand imbalances in modern power grids, motivating the development of energy management systems that can coordinate distributed resources without sacrificing local control responsiveness. This paper presents qToggleEMS, a distributed architecture that combines cloud-resident receding-horizon planning with edge-resident bounded-override control for prosumer sites equipped with photovoltaic generation, battery storage, and grid interconnection. The contribution is positioned at the systems-engineering level: a documented partitioning of responsibilities between a cloud planner (forecasting, price-aware scheduling) and an edge controller (sub-second actuation, autonomous fallback) that preserves planning quality while remaining operational under cloud–edge disconnection. The cloud component, powerHub, is implemented as a set of microservices communicating via MQTT and TimescaleDB; the edge component runs qToggleOS on an ARM single-board computer and accesses inverters directly via Modbus RTU, bypassing manufacturer-provided cloud APIs. The system was deployed at a commercial prosumer site for approximately two months using the prosumer-oriented optimization strategy. Compared with a within-period counterfactual baseline (the cost the site would have incurred under its previous flat-tariff contract), monthly energy costs decreased by 14–15%. An analytical projection of the producer-oriented strategy using historical day-ahead prices from OPCOM PZU suggests a revenue uplift of approximately 23%, pending field validation. Full article

This study evaluates the wind energy potential of Polokwane, South Africa, using statistical distribution models to estimate wind power density (WPD) and assess turbine performance under low-wind inland conditions. Hourly wind speed and direction data (2015–2024) measured at a 10 m height above ground level (AGL) were analysed to characterise wind behaviour and assess energy availability. Four probability distributions, namely generalised logistic (GLD), generalised extreme value (GEVD), Gumbel (GD), and Weibull (WD), were fitted using the maximum likelihood (ML) method. Model performance was evaluated using Kolmogorov–Smirnov (KS), Anderson–Darling (AD), and Chi-square $\left({\chi }^2\right)$ tests, while wind power density accuracy was assessed using wind power density error (WPDE). The results showed that Polokwane is characterised by low wind speeds, with an overall mean wind speed of 2.72 m/s at 10 m AGL, reaching a low of 3.88 m/s at a hub height of 125 m. The GEVD model produced the most accurate wind power density estimate of 32.37 W/m², classifying the site within the poor wind resource category. Wind direction analysis revealed a dominant northeast sector with seasonal shifts toward the south. Wind turbine performance analysis showed improved energy generation at higher hub heights, with the Gamesa G136-4.5 MW turbine identified as the most suitable option for the site, achieving the highest net annual energy production (AEP) of 10.82 GWh/yr and the highest net capacity factor (CF) of 27.44%. These results indicate that the Polokwane site is suitable for low-to-moderate wind energy applications and small-scale distributed wind generation rather than large-scale commercial wind farm development. Full article

This concept paper advances stigma power as a central analytical mechanism for understanding how patriarchy, capitalism, white supremacy, and cis-heteronormativity operate with particular intensity against sex workers. Integrating Link and Phelan’s stigma power with Bourdieu’s symbolic violence and Foucauldian productive power, the framework theorises stigma as a mechanism institutionalised through law and enforced by institutions, which produces measurable consequences that include violence, exclusion, and health harms. Analysing the intersecting axes of gender, sexuality, race, migration, and class across three qualitative studies (SWMH, SEXHUM, VICSW), the article demonstrates why labour-rights reforms, including decriminalisation, are necessary but insufficient. Dismantling stigma requires not only removing sanctions but actively contesting the actors exercising stigma power and interrupting the stabilising mechanisms that reproduce it. This requires policy that acknowledges stigma’s existence whilst working to dismantle it, rather than eliding its reality through liberal mainstreaming or strengthening it through criminalisation or rescue frameworks. The framework explains why decriminalisation is associated with better access to rights and health; why all criminalisation including the so-called Swedish model correlates with increased violence; why stigma persists under optimal legal conditions; and how intersecting marginalisations produce differential vulnerability. Policy implications emphasise pairing decriminalisation with peer-led anti-stigma work, institutional reform, migrant rights, and funded support for sex worker self-organisation. Full article

Electrocatalytic CO₂ reduction reaction (CO₂RR) to ethylene (C₂H₄) has emerged as a promising approach for converting CO₂ into valuable chemicals while utilizing renewable electricity. To facilitate the commercialization of this technology, a process-level techno-economic assessment (TEA) is constructed for a plant producing 100 tons/day of C₂H₄ from coal-power flue gas CO₂ using a membrane electrode assembly (MEA) electrolyzer and downstream gas separations. The model integrates (i) flue gas CO₂ capture by chemical absorption, (ii) CO₂RR to C₂H₄ with H₂ as the only co-product, and (iii) cathode off-gas separation by pressure swing adsorption (PSA) plus anode off-gas CO₂ recovery and recycle. A Cu₁₀–Sn catalyst measured in an H-cell is projected to MEA operation by scaling current density by 10×, yielding a “Case Study in This Article” scenario of j = 246 mA·cm⁻² and FE(C₂H₄) = 48.74%. Under this scenario, the total cost is 592.61 thousand USD/day (5926 USD/ton), dominated by electricity (39.8%). Scenario analysis shows that the total cost can decrease to 76,755.0 USD/day (767.6 USD/ton) under a future-outlook case with improved electrolyzer performance and low-cost power, enabling a net profit of 19,945.0 USD/day at an ethylene selling price of 967 USD/ton. Sensitivity analysis identifies FE(C₂H₄), full-cell voltage, and electricity price as the most influential variables. The results translate laboratory catalyst metrics into industrial cost drivers and clarify quantitative performance targets for commercialization. Full article

This paper focuses on the early Qing monk-painter Hongren 弘仁, systematically exploring the pathways through which the Chan Buddhist “emptiness contemplation” is manifested in his landscape paintings. As a representative monk-painter, Hongren produced works that profoundly embody the Chan contemplation of emptiness, yielding a singular style defined by austere coldness, minimalist simplicity, and profound quietude. Transcending conventional stylistic descriptions in art history and essentialist philosophical deductions, this study adopts a comprehensive empirical approach that integrates poetry, calligraphy, painting, and seals (shi-shu-hua-yin 诗书画印). By adopting an interdisciplinary perspective of philosophy, religion, and art history, this study argues that Hongren’s landscapes are not merely subjective emotional expressions or aesthetic pursuits; rather, they constitute a visual extension and a spiritual externalization of his emptiness contemplation. Through a multi-layered analysis of his form, brushwork, composition, and artistic conception, combined with the mutual corroboration of poetic inscriptions on paintings and textual inscriptions on seals, this paper reveals how the Chan philosophy of “emptiness contemplation” is reflected within his artistic language. While Hongren’s style is the cumulative result of various factors such as the Ming-Qing dynasty transition, his personal life, the inheritance of painting techniques, and the regional culture of Mount Huang, this paper specifically takes Chan thought as its analytical starting point, focusing on its unique expression in his work. Hongren’s path of “Painting-Chan” (hua chan 画禅) not only infused early Qing painting with a sublime spiritual power but also provides a vital religious exegesis of the deep-seated Chinese tradition of “Technique Ascending to the Dao” (ji jin yu dao 技进于道). Full article

Satellite-based assessment of power tower damage is essential for rapid disaster response but is challenged by the scarcity of damage samples and the cross-scale mismatch between close-range UAV imagery and satellite imagery. Existing data augmentation methods, including copy-based strategies and diffusion-based generation, often fail to produce reliable samples due to their dependence on the training data distribution and the lack of explicit control over object scale and domain discrepancy. To address these issues, we propose a scale-constrained and frequency-adaptive diffusion-based data construction framework that explicitly models the scale distribution prior of power towers in the remote sensing domain and incorporates frequency-domain adaptation before image generation. Specifically, scale-aware instance embedding is used to construct training samples that conform to satellite-scale statistics, while frequency-domain adaptation is introduced to reduce spectral and texture discrepancies between UAV-derived damaged references and satellite imagery. A diffusion-based inpainting model is then trained on the constructed dataset to reconstruct damage at original tower locations. The experimental results, including feature statistical analysis and downstream change detection validation, demonstrate that the proposed method achieves better alignment with real satellite-scale distributions, reduces geometric and spectral–textural inconsistencies, and improves boundary continuity and structural realism under cross-resolution conditions. Full article