Search Results (420)

Brazil is the main coffee producer in the world. However, the impacts of climate change driven by greenhouse gas (GHG) emissions pose a major challenge for agriculture in tropical regions. This study established a GHG inventory of coffee production on farms in southern Minas Gerais, Brazil, over a two-year period, adopting a cradle-to-farm-gate approach. It considered scopes 1 and 2 emissions from on-farm activities. The emission inventories were based on Intergovernmental Panel on Climate Change (IPCC) methodologies adapted for Brazilian conditions. The emissions were categorized in direct and biogenic and by area (in hectares) and production (kg of coffee). Electricity consumption, fossil fuel use, wood burning and fertilizer application were considered. Direct total emissions ranged from 2617 to 6211 t CO₂e, 2.67 to 3.81 t CO₂e ha⁻¹, and from 1.52 to 4.59 kg CO₂e kg⁻¹ of coffee. Biogenic emissions ranged from 336 to 4955 t CO₂e, 0.28 to 2.95 t CO₂e ha⁻¹, and from 0.32 to 2.21 kg CO₂e kg⁻¹ of coffee. Urea-based nitrogen fertilizers were the main source of direct emission and wood burning was the main source of biogenic emission. Management practices such as applying non-urea-based fertilizers, adjusting nitrogen rates according to soil analyses and manual harvesting contributed to mitigating GHG emissions. The observed emission intensities were consistent with other reported values for Brazilian coffee production. Further reductions may be achieved by adopting agroforestry systems, increasing coffee straw retention in the soil and replacing urea with alternative nitrogen sources, including slow-release fertilizers and urease-inhibitor technologies. Full article

Lightning-induced breaking accidents of medium-voltage insulated conductors pose a serious threat to the safety of distribution networks, and the key cause lies in the establishment and sustained combustion of the power-frequency follow-current arc after lightning overvoltage breakdown. This paper systematically investigates the formation mechanism and critical conditions of power-frequency follow-current arcs using combined simulation and experimental approaches. Based on the streamer discharge theory, a lightning breakdown model was established and combined with the arc energy balance equation, revealing that the establishment of power-frequency follow-current arcs is essentially determined by the post-breakdown energy competition process. The simulation results show that the required anode electric field strength for lightning breakdown is not less than 3 kV/mm. When the power-frequency voltage reaches 10 kV, Joule heating of the arc continuously exceeds heat dissipation loss, enabling restrike after zero-crossing and sustaining stable burning. Experiments verified this voltage threshold and further revealed that the arc establishment rate exhibits nonlinear growth with increasing power-frequency voltage, exceeding 90% at power-frequency voltages ≥ 10 kV. The study also reveals that increased gap distance reduces the arc establishment rate, while the introduction of insulators can enhance it by approximately 20%. This study clarifies the energy criterion for power-frequency follow-current arc establishment and the influence patterns of key parameters, providing theoretical basis and engineering reference for lightning protection design and arc suppression in medium-voltage insulated lines. Full article

Rice husk, which accounts for approximately 22% of global rice production, is often disposed of by open field burning, causing significant greenhouse gas (GHG) emissions and air pollution. Converting rice husk into biochar via pyrolysis offers a sustainable waste management and climate mitigation pathway; however, the environmental performance of biochar production is highly sensitive to the energy source used. Hence, this study presents a gate-to-gate life cycle assessment of biochar production from rice husk via slow pyrolysis at 500 °C under three energy supply scenarios: grid electricity, biomass combustion, and photovoltaic solar energy. Using the ReCiPe 2016 methodology, environmental impacts were evaluated across four categories such as Global Warming Potential (GWP), Human Toxicity Potential (HTP), Acidification Potential (AP), and Abiotic Depletion Potential (ADP), with all process parameters held constant except the energy source. The results demonstrate that energy supply is the dominant determinant of environmental performance and the photovoltaic solar-assisted biochar production route showed superior performance across all categories, with gross production impacts for 1 ton biochar of 24.0 kg CO₂-eq (GWP), 5.6 kg 1,4-DCB-eq (HTP), 0.09 kg SO₂-eq (AP), and 259.9 MJ (ADP), representing 48-165-fold improvements over grid electricity. When accounting for carbon sequestration (2800 kg CO₂-eq per ton biochar), all scenarios achieved net negative GWP, ranging from −2776.0 kg CO₂-eq (solar PV) to −1562.5 kg CO₂-eq (grid electricity), representing 78% variation attributable to energy source. Contribution analysis revealed pyrolysis heating accounts for 95.6% of environmental impacts, with no trade-offs among impact categories. The findings recommend photovoltaic solar energy for new biochar facilities, biomass combustion for co-located agricultural operations, and avoidance of grid electricity unless grids achieve substantial decarbonization. Full article

To quantitatively elucidate the effects of overload current on the ignition and burning hazards of polyethylene-insulated wires, 2.5 mm² polyethylene-insulated copper wires used commercially were tested in an electrical fire fault simulation system. Experiments were conducted to study the evolution of overloads, ignition, and burning. The entire process, from insulation smoking and ignition to sustained burning and final extinction driven by wire fusing, was recorded using synchronized digital and high-speed imaging. Video-based measurements were used to extract the following: smoking emission duration, ignition time, burning duration, maximum flame height, and segmented flame width. The results show that stable ignition and sustained burning occur when the overload current is greater than or equal to 180 A. As the current increases, ignition occurs earlier, while the smoking stage becomes shorter but exhibits nonmonotonic fluctuations. The burning duration shows a staged response. It first increases, then decreases toward a relatively stable level. This reflects the competition between enhanced Joule heating and accelerated wire melting and fusing. Maximum flame height and segmented flame width vary nonmonotonically with current, and the segmented flame width peaks at 200 A. A multi-indicator fire hazard evaluation framework was established and an entropy-weight TOPSIS method was applied to integrate the quantification and ranking. The overall fire hazard is greatest at 200 A. These findings provide experimental insight into overload-induced ignition and combustion behavior and contribute to a quantitative understanding of fire hazard evolution in overloaded electrical wires. Full article

Background/Objectives: High-voltage, low-current electric shocks inflict superficial second-degree burns on the skin, accompanied by a vicious cycle of excessive oxidative stress and inflammation. As efficient treatment of such electrical burns remains a clinical challenge, we explored the efficacy of an injectable thermosensitive chitosan hydrogel engineered with an antioxidant agent (astaxanthin) and an anti-inflammatory agent (ibuprofen) for the treatment of high-voltage, low-current electrical burn injuries. Methods: The proposed CS/AST/IBU hydrogel was prepared and its thermosensitivity was characterized. Subsequently, the hydrogel was injected into the wounds of male Sprague–Dawley (SD) rats subjected to electrical burn injury (20 kV, 3 mA). Finally, a series of experiments were performed to elucidate the dynamics of wound healing and the mechanisms by which the hydrogel promotes wound repair. Results: The injectable hydrogel, through its thermally responsive gelation effect at 37 °C, adapts to the complex irregularities of the wound surface. This facilitates the release of astaxanthin and ibuprofen throughout the wound, which collectively diminish the formation of reactive oxygen species and MDA. Furthermore, it enhances the synthesis of endogenous antioxidants such as SOD, CAT, and GSH; encourages collagen deposition; stimulates the development of dermal appendages; and fosters neovascularization. It interrupts the deleterious cycle of oxidative stress and inflammation mediated by the NF-κB signaling pathway, thereby suppressing the expression of pro-inflammatory markers such as TNF-α, CD11b, and IL-1β while upregulating CD163, an anti-inflammatory receptor. Conclusions: The use of this multipronged, contour-adaptive hydrogel represents an effective strategy for complex wound management and demonstrates broad therapeutic potential for superficial second-degree electrical burns caused by high-voltage, low-current discharge. Full article

The pantograph–catenary system is a critical component of the traction power supply network. Due to hard points on the overhead contact line and vibrations of the pantograph, pantograph–catenary separation may occur, leading to offline DC arc events. To investigate the characteristics of DC arcs generated during pantograph–catenary separation in metro systems, this study constructs a laboratory platform that simulates the offline process and analyzes the electrical characteristics, optical intensity, and arc-burn duration under different electrode separation conditions. First, a DC pantograph–catenary offline arc simulation platform is developed using a contact wire, a carbon-strip pantograph slider, and a linear motor, enabling slider movement in both horizontal and vertical directions. Second, offline discharge experiments are conducted to compare the discharge process and electrical arc characteristics with and without horizontal slider motion. Finally, arc luminosity and burn duration are measured under various electrode separation configurations, and the influence of voltage level, current level, and electrode material is examined. Experimental results reveal a significant polarity effect, where the arc burn duration is notably longer when the contact wire serves as the cathode than when the carbon slider serves as the cathode. At the instant of separation, the high electric field intensity within the micro-gap triggers pronounced “peak phenomena” in both arc resistance and power, accompanied by abrupt voltage surges and transient current dips. Furthermore, the introduction of horizontal motion modulates the arcing process, causing the stable arcing voltage to follow a distinctive trend of a slow increase followed by a gradual decrease, which differs from static separation characteristics. Finally, this study demonstrates that voltage levels exert a more dominant influence on arc luminosity and duration than current levels, while the maintenance voltage of the arc channel remains significantly lower than the air breakdown voltage. Full article

Background: Electrical injuries occur when an electric current comes into contact with or passes through the body. Electrical injuries can result from contact with faulty electrical appliances and machinery or from contact with open household wiring or electrical power lines. Aim: The aim of this study was to evaluate the psychosocial difficulties experienced by individuals who suffered electrical burns due to work accidents, using a phenomenological approach. Study Design: This phenomenological study was conducted with semi-structured in-depth interviews with 15 electrical burn survivors living in different regions of Turkey via the WhatsApp mobile application. The snowball sampling method was used to reach the sample group. Interviews continued until data saturation was achieved. All interviews were audio recorded and then transcribed. The data were analyzed using Colaizzi’s phenomenological analysis method. The study was conducted and reported according to the COREQ checklist. Results: In the analysis of the data, two categories and five themes were identified: the effects of electrical burn at the time of occurrence and during the hospital process (psychological, social and physical), and adaptation to life after electrical burn treatment (emotions experienced, difficulties experienced and coping). Conclusions: This study revealed the life experiences, psychosocial difficulties and coping experiences of individuals with electrical burns. According to the results of the research, it is understood that individuals experienced negative emotions such as depression, helplessness and hopelessness as a result of electrical burns, could not cope with the psychosocial difficulties experienced and received psychological support. It was determined that social appearance anxiety due to deterioration in body image was very important in individuals. Full article

Objective: Inferior alveolar (IAN) and lingual nerve (LN) injuries are known complications of impacted mandibular third molar surgery and may result in persistent neurosensory deficits. This exploratory, non-randomized clinical study evaluated the clinical and electrophysiological effects of low-level laser therapy (LLLT) and transcutaneous electrical nerve stimulation (TENS) on neurosensory recovery following trigeminal nerve injury. Methods: Twenty-seven patients with postoperative IAN or LN injury received LLLT, TENS, or placebo therapy according to institutional clinical protocols. Clinical outcomes were assessed using Visual Analog Scale (VAS) scores, and electrophysiological evaluation was performed using electromyography by measuring cutaneous silent period (CSP) duration. Non-parametric statistical analyses were conducted using the Wilcoxon signed-rank and Mann–Whitney U tests. Results: LLLT was associated with statistically significant improvements in several neurosensory symptoms, including pain, burning sensation, speech difficulty, biting, and taste disturbance. In contrast, TENS and placebo treatment did not demonstrate a consistent or generalized improvement across neurosensory outcomes. CSP durations differed significantly between healthy and pathological sides both before and after treatment. Although CSP duration showed a tendency to increase following LLLT, these changes did not reach statistical significance. Subgroup analysis revealed greater clinical improvement in LN injuries compared with IAN injuries within the LLLT group. Conclusions: Within the limitations of this exploratory study, LLLT was associated with more pronounced clinical improvement than TENS or placebo in patients with third molar-related trigeminal nerve injury. CSP measurements provided supportive objective information, although electrophysiological recovery remained limited. Full article

PM_2.5 pollution has become one of the major environmental issues in Shandong Province in recent years. High concentrations of PM_2.5 not only reduce atmospheric visibility but also induce respiratory and cardiovascular diseases, and significantly increase health risks. Source apportionment of PM_2.5 is important for policy makers to determine control strategies. This study analyzed regional and sectoral PM_2.5 sources across 17 Shandong cities during the 2017–2018 winter heating season, which is selected because it is representative of severe air pollution with an average PM_2.5 of 65.75 μg/m³ and hourly peak exceeding 250 μg/m³. This air pollution episode aligned with key control policies, where seven major cities implemented steel capacity reduction and coal-to-gas/electric heating, as a baseline for evaluating emission reduction effectiveness. The particulate matter source apportionment technology in the Comprehensive Air Quality Model with extensions (CAMx) was applied to simulate the source contributions to PM_2.5 in 17 cities from different regions and sectors including industry, residence, transportation, and coal-burning power plants. The meteorological fields required for the CAMx model were generated using the Weather Research and Forecasting (WRF) model. The results showed that all cities besides Dezhou city in Shandong Province contributed PM_2.5 locally, varying from 39% to 53%. The emissions from Hebei province have a large impact on the PM_2.5 concentrations in Shandong Province. The non-local industrial and residential sources in Shandong Province accounted for the prominent proportion of local PM_2.5 in all cities. The contribution of non-local industrial sources to PM_2.5 in Heze City was up to 56.99%. As for Zibo City, the largest contribution of PM_2.5 was from non-local residential sources, around 56%. Additionally, the local industrial and residential sources in Jinan and Rizhao cities had relatively more contributions to the local PM_2.5 concentrations compared to the other cities in Shandong Province. Finally, the emission reduction effects were evaluated by applying different reduction ratios of local industrial and transportation sources, with decreases in PM_2.5 concentrations ranging from 0.2 to 26 µg/m³ in each city. Full article

Water from mountain regions is a crucial natural resource because of its major economic, social, and environmental significance. Wildfires may disrupt the normal functioning of the hydrological cycle, limiting water resources for nearby areas and degrading water quality in mountainous regions as contaminants enter water systems from the burning of vegetation and soil. In August 2022, the Serra da Estrela mountain, situated in the Mediterranean biogeographical region, was affected by a large wildfire that consumed 270 km² of the Serra da Estrela Natural Park, often resulting in severe vegetation burn, although the soil burn severity was low to moderate in most of the area. The research objective is to assess the impact of this wildfire on the hydrogeochemistry of groundwater and surface water in the Manteigas-Covão da Ametade sector of Serra da Estrela in the context of a wildfire with limited soil burn severity. Groundwater and surface water samples were collected from October 2022 to September 2023 and were analyzed for pH, Total Organic Carbon, electrical conductivity, major ions, potentially toxic elements, iron (Fe), and Polycyclic Aromatic Hydrocarbons. A stormy event in mid-September 2022, occurring before the first sampling campaign, removed most of the ash layer and likely caused transient hydrogeochemical changes in streams. However, the analytical results from the sampled waters revealed that the post-wildfire hydrogeochemical effects are not evident. In fact, the hydrogeochemical changes observed in groundwater and surface water appear to be primarily influenced by the regular hydrological behaviour of aquifers and streams. The low to moderate soil burn severity, the high soil hydrophobicity, and the temporal distribution of precipitation explain why the hydrogeochemistry was primarily influenced by groundwater flow paths, the types and weathering of local lithologies, soil types, dilution effects following wet periods, and seasonal changes in the tributaries feeding into streams, rather than by post-wildfire effects. These outcomes provide valuable insights for water resource management and for developing strategies to mitigate wildfire impacts in mountainous environments. Full article

Background: This study investigates the influence of emotional processing on flexor reflex responses in the upper limbs, focusing on cutaneomuscular reflexes (CMRs) and the cutaneous silent period (CSP) in patients with chronic neuropathic pain. The modulation of motor reflexes by emotions remains unclear. Methods: Fifty-one patients with chronic upper limb neuropathic pain (carpal tunnel syndrome, other neuropathies, post-burn hypertrophic scars) and twenty healthy controls underwent standardized electrodiagnostic signal acquisition. Neurophysiological assessments (CMRs, CSP, standard nerve conduction tests) and psychological evaluations (anxiety, depression, emotion processing) were conducted. Neurophysiological signal acquisition included median and ulnar nerve conduction studies recorded with an electrodiagnostic system (48 kHz sampling rate; 30–3000 Hz bandpass). CSP and CMRs were recorded from the abductor pollicis brevis using surface electrodes (bipolar belly–tendon montage) and were evoked by electrical stimulation delivered through ring electrodes, with individualized perceptual-threshold calibration. Statistical analyses examined correlations between neurophysiological and psychological measures. Results: Patients showed significantly longer duration and higher intensity of CMRs and CSP than controls (p < 0.01). CMR and CSP durations correlated positively with anxiety, depression, and alexithymia scores, and negatively with facial emotion recognition. General Linear Model analyses indicated these relations were mediated by tactile and pain perception thresholds. Conclusions: The findings support that spinal reflex responses in the upper limbs are modulated by emotional and cognitive-affective processes, especially in chronic pain contexts. This highlights the complex interaction between emotion regulation and motor control in neuropathic pain conditions. Full article

The rapid growth of electric vehicles (EVs) has introduced new fire safety challenges for the built environment, particularly within reinforced concrete structures. Fires involving lithium-ion batteries are substantially different from conventional hydrocarbon-fuelled fires due to their rapid heat escalation, extended burning duration, and potential for re-ignition caused by thermal runaway. This study assesses the adequacy of existing fire design standards in addressing these emerging hazards, emphasising the spalling behaviour of concrete under EV induced fire exposure. The study found that concrete structures are highly vulnerable to spalling when exposed to EV fires, as the typical temperatures initiating concrete spalling are significantly lower than the extreme temperatures and re-ignition produced during an EV battery fire. Moreover, the evidence suggests that EV fires can sustain peak temperatures exceeding 1000 °C in a short period, which exceeds the assumptions underlying standard fire curves, such as ISO 834. A comparative assessment of the National Construction Code (NCC 2022) and standards (i.e., AS 1530.4, EN 1992-1-2) reveals that current design methodologies and fire-resistance ratings underestimate the severity and duration of EV fire conditions. This study also proposes code-aligned improvements and a performance-based evaluation framework that integrates empirical EV fire curves. The findings highlight a pressing need to re-examine fire design provisions and update thermal exposure assumptions to ensure that reinforced concrete infrastructure remains structurally safe and reliable as EV adoption increases. Full article

The construction sector faces pressure to decarbonise while addressing rising resource demands and agricultural waste. Ordinary Portland cement (OPC) is a major CO₂ emitter, yet biomass residues are often open-burned or landfilled. This study explores corncob ash (CCA) as a sustainable supplementary cementitious material (SCM), examining how calcination conditions influence pozzolanic potential and support circular economy and climate goals, which have not been adequately explored in literature. Ten CCA samples were produced via open-air burning (2–3.5 h) and electric-furnace calcination (400–1000 °C, 2 h), alongside a reference OPC. Mass yield, colour, XRD, XRF, LOI, and LOD were analysed within a process–structure–property–performance–sustainability framework. CCA produced in a 400–700 °C furnace window consistently achieved high amorphous contents (typically ≥80%) and combined pozzolanic oxides (SiO₂ + Al₂O₃ + Fe₂O₃) above the 70% ASTM C618 threshold, with 700 °C for 2 h emerging as an optimal condition. At 1000 °C, extensive crystallisation reduced the expected reactivity despite high total silica. Extended open-air burning (3–3.5 h) yielded chemically acceptable but more variable ashes, with lower amorphous content and higher alkalis than furnace-processed CCA. Simple industrial ecology calculations indicate that valorising a fraction of global CC residues and deploying optimally processed CCA at only 20% OPC replacement could displace 180 million tonnes CC waste and clinker avoidance on the order of 5–6 Mt CO₂ per year, while reducing uncontrolled residue burning and primary raw material extraction. The study provides an experimentally validated calcination window and quality indicators for producing reactive CCA, alongside a clear link from laboratory processing to clinker substitution, circular resource use, and alignment with SDGs 9, 12, and 13. The findings establish a materials science foundation for standardised CCA production protocols and future life cycle and performance evaluations of low-carbon CCA binders. Full article

The article presents a blockchain-based architecture for decentralized electricity trading that tokenizes energy delivery rights and cash-flows. Energy Attribute Certificates (EACs) are implemented as NFTs, while buy/sell orders are encoded as ERC-1155 tokens whose tokenId packs a time slot and price, enabling precise matching across hours. A clearing smart contract (Matcher) burns filled orders, mints an NFT option, and issues two ERC-20 assets: PT, the right to consume kWh within a specified interval, and YT, the producer’s claim on revenue. We propose a simple, linearly increasing discounted buyback for YT within the slot and introduce an aggregating token, IndexYT, which accumulates YTs across slots, redeems them at par at maturity, and gradually builds on-chain reserves—turning IndexYT into a liquid, yield-bearing instrument. We outline the PT/YY lifecycle, oracle-driven policy controls for DSO (e.g., transfer/splitting constraints), and discuss transparency, resilience, and capital efficiency. The contribution is a Pendle-inspired split of electricity into Principal/Yield tokens combined with a time-stamped on-chain order book and IndexYT, forming a programmable market for short-term delivery rights and yield derivatives with deterministic settlement. Full article

Background: Despite advances in myoelectric control of hand prostheses, their dropout rate remains high. Methods: We analyzed 37 features extracted from surface electromyography (sEMG) recordings from 15 participants, distributed into three groups: non-impaired individuals, impaired individuals with limb loss due to trauma, and impaired individuals with limb loss due to electrical burn. Feature relationships were examined with correlation heatmaps and two feature-selection methods (ReliefF and Minimal Redundancy Maximum Relevance), and classification performance was evaluated using machine-learning models to characterize sEMG behavior across groups. Results: Individuals with electrical-burn injury exhibited increased forearm co-contraction on the affected side across normalized isometric contractions, indicating altered motor coordination and likely higher energetic cost for prosthetic control. Feature selection and model results revealed etiology-dependent differences in the most informative sEMG features, underscoring the need for personalized, etiology-aware myoelectric control strategies. Conclusions: These findings inform the design of adaptive prosthetic controllers and targeted rehabilitation protocols that account for injury-specific motor control adaptations. Full article