Search Results (1,119)

In electric vehicle (EV) drivetrains, lubricant films must not only mitigate friction and wear but also manage stray currents to safely dissipate stray charge and avoid micro-arcing. This study directly compares how a conventional antiwear additive (ZDDP) and a long-chain, ashless, sulfur-free phosphite ester (Duraphos AP240L) manage this balance under current-carrying boundary lubrication conditions. Reciprocating steel-on-steel tests were conducted at fixed load and speed with applied current densities of 0, 0.02, and 42.4 A/cm². Friction and four-probe electrical contact resistance (ECR) were measured in situ, and impedance of tribofilms was measured over a 1–10⁵ Hz range after friction test. In the presence of ZDDP, ECR initially increased and then decreased to a value that was as low as the initial direct contact of two solid surfaces or even lower sometimes. During the initial stage with high ECR, a well-defined impedance semicircle was observed in the Nyquist plot; after forming the tribofilm with low ECR, frequency dependence of impedance could not be measured due to the very low resistance. The decrease in ECR suggested a structural evolution of the anti-wear film on the substrate. However, post-test wear analysis indicated that the formation of this film was accompanied by tribochemical polishing of the countersurface and sometimes pitting of the substrate, which may have been due to localized electrical discharge producing trenches deeper than ~0.5 µm; in additive-free base oil, wear was dominated by ploughing with micro-cutting of the substrate. In contrast, AP240L performed better in terms of friction and wear, showing a remarkable ~30% lower coefficient of friction, while the overall cycle dependence of ECR was similar to the ZDDP case. AP240L showed negligible boundary film controlled wear producing a shallow, smooth track (depth < 0.2 µm) during the friction test, and there was no sign of electrical arc damage. These findings support long-chain, ashless, sulfur-free phosphite esters as promising candidates for EV boundary lubrication where both mechanical and electrical protection are required. Full article

The scour process of sand particles and multi-grain size and density particles were studied to investigate the segregation process of different particles in a confined channel. The effects of jet intensity and submergence as two controlling parameters were studied, and scour characteristics and profiles were measured. The time history of the scouring process was measured and the results were compared with the scour process in a uniform sand bed as benchmark tests. Experimental data revealed that the eroded area of different particle types increased with the jet intensity, but the erosion of relatively heavier particles was limited due to jet diffusion. The local erosion was affected by the level of submergence and more erosion occurred near the nozzle at low submergence. Increasing the jet Froude number increased the area of deposition, while submergence reduced the overall area of deposition. As submergence increased from 4 to 12, the area of sand particles reduced by more than 50% while the jet intensity was constant. In shallow submergence, increasing jet intensity from 1.46 to 2.11 increased the area of lead balls by 120%, whereas in relatively deep submergence, incrementing jet intensity increased the area of lead balls by more than five times. The effect of flow intensity on variations of scour dimensions was quantified by the densimetric Froude number. While a densimetric Froude number based on mean particle size, D₅₀, was found to be suitable to estimate maximum scour bed in uniform sand beds, experimental data indicated that the best fit is achievable to predict maximum scour depth in multi-grain size and density once D₉₅ is used. Semi-empirical models were proposed to predict scour dimensions as a function of the densimetric Froude number. Full article

During the discharge process of a salt cavern compressed air energy storage (CAES) system, high-speed air flow may entrain salt slag from the cavern floor, posing a threat to pipeline safety. Currently, there is a lack of in-depth research into the transient mechanisms of the entrainment process, particularly the influence of particle shape. This study employs a CFD-DEM coupling approach to conduct, for the first time, a high-fidelity simulation of slag entrainment dynamics during the initial discharge phase of a salt cavern CAES system, with a focus on the motion patterns of three particle shapes: spherical, conical, and square. Results show that: (1) during the initial discharge stage, the flow field rapidly forms vortex structures that migrate toward the wellhead, which is the core mechanism driving particle mobilization; (2) particle shape significantly affects entrainment efficiency through frictional characteristics—spherical particles are most easily entrained (maximum entrainment rate of 0.42 kg/h), while non-spherical particles tend to accumulate below the wellhead; and (3) the entrainment process exhibits strong transient characteristics: the entrainment rate peaks rapidly (approximately 0.82 kg/h) within a short time and then declines sharply, and it is sensitive to particle size, with the most entrainable particle size being around 5 mm. This study reveals the coupling mechanism between transient vortices and multi-shape particle entrainment during discharge, providing a theoretical basis for the design of filtration systems, operational risk prevention, and slag removal strategies in salt cavern CAES power plants. Full article

The integration of a user-side energy storage system (ESS) faces notable economic challenges, including high upfront investment, uncertainty in quantifying battery degradation, and fragmented ancillary service revenue streams, which hinder large-scale deployment. Conventional configuration studies often handle capacity planning and operational scheduling at different stages, complicating consistent life-cycle valuation under degradation and multi-service participation. This paper proposes a life-cycle multi-service co-optimization model (LC-MSCOM) to jointly determine ESS power–energy ratings and operating strategies. A unified revenue framework quantifies stacked revenues from time-of-use arbitrage, demand charge management, demand response, and renewable energy accommodation, while depth of discharge (DoD)-related lifetime loss is converted into an equivalent degradation cost and embedded in the optimization. The model is validated on a modified IEEE benchmark system using real generation and load data. Results show that LC-MSCOM increases net present value (NPV) by 26.8% and reduces discounted payback period (DPP) by 12.7% relative to conventional benchmarks, and sensitivity analyses confirm robustness under discount-rate, inflation-rate, and tariff uncertainties. By coordinating ESS dispatch with distribution network operating limits (nodal power balance, voltage bounds, and branch ampacity constraints), the framework provides practical, investment-oriented decision support for user-side ESS deployment. Full article

Background: Neonatal mortality remains a significant public health challenge in Ethiopia. Despite efforts to implement key evidence-based interventions, their coverage and utilization remain low. The Saving Little Lives (SLL) program aims to scale-up a Minimum Care Package (MCP) of synergistic, life-saving interventions for all liveborn neonates, with a focus on preterm and low birth weight (LBW) infants, across 290 hospitals in Ethiopia (206 primary, 69 general, and 15 referral hospitals), representing 82% of all hospitals in the country at the time of the study, and evaluate the impact on neonatal mortality. Methods: A non-randomized stepped-wedge trial will be conducted to evaluate the impact of implementing the SLL MCP interventions. Quantitative evaluation data will be collected from 36 primary hospitals, selected from 206 primary hospitals across four regions, receiving the interventions. An independent evaluation research assistant will be deployed in each of the hospitals to collect data using Open Data Kit (ODK) through interviewing mothers before discharge, on the 29th day of life if discharged, and reviewing medical records. A mixed-method, cross-sectional formative assessment will be conducted prior to implementation, employing quantitative facility assessment and qualitative interviews with mothers, healthcare providers, and facility managers. This will be followed by continuous program learning assessment once implementation begins. Descriptive data will be presented using numbers, percentages, tables, and graphs. Regression modeling and generalized estimating equations (GEEs) will be used to estimate the impact of the SLL MCP interventions. Qualitative data will be gathered through in-depth interviews, digitally recorded, transcribed, and thematically analyzed using ATLAS.ti Version 7.5 software to assess facility readiness, barriers, and enablers of implementing the SLL MCP interventions. Expected Outcome: We hypothesize that achieving 80% coverage of the SLL MCP interventions among eligible neonates will result in a 35% reduction in neonatal mortality at implementation facilities. Full article

Background/Objectives: In order to develop a comprehensive understanding of gastric-type endocervical adenocarcinoma (GEA), an increasingly prevalent HPV-independent cervical cancer, we summarized clinicopathological information and performed prognostic analysis. Methods: A total of 182 patients diagnosed with GEA at our center during the period 2014–2025 were included in this study. Nineteen GEA cases, 6 HPV-independent non-GEA cases, 59 HPV-associated usual endocervical adenocarcinoma cases, and 66 squamous cell carcinoma cases from online database were also included. Results: Vaginal bleeding (39.56%) and watery discharge (35.16%) were the most common symptoms. As many as 21.43% of patients had no specific complaints, and 80% of GEA showed no distinct mass through gynecological examination. A total of 64% of GEA were stage IIB–IV at diagnosis, with a 5-year survival of 41% versus 85% for stage I–IIA (p < 0.05). The rate of lymphovascular space invasion (LVSI), lymph node metastasis, and ovarian metastasis were 49.64%, 42.00%, and 29.29%, respectively. The 5-year survival and recurrence rates after primary therapy were 57% and 23%, respectively. For GEA treatment, surgery might be associated with improved overall survival for the population at stage III–IV. Survival analysis identified deep infiltration depth (≥2/3), a maximum diameter of the tumor (MDOT) of ≥3 cm, and ovary metastasis as potential indicators of worse OS and PFS for whole patients. Additionally, ovary metastasis indicated poor PFS and OS for stage I–II. Genomic information TP53 mutation, PTEN deletion and STK11 mutation might be the most prevalent genomic alterations. Conclusions: These findings indicated GEA as an aggressive cervical cancer, with high rate of lymph node metastasis, high recurrence rate and short 5-year survival. Ovary metastasis reflected advanced disease burden and surgery might be associated with improved survival in advanced stage. For genomic information, GEA showed genetic heterogeneity and a low level of genomic instability. Full article

Interactions between surface water and groundwater in arid regions regulate their response to climate and human impacts. In the salar systems of the Altiplano-Puna plateau (Bolivia, Chile, Argentina), understanding how surface waters connect to groundwater is crucial for accurate modeling and assessment. This study introduces new data and analysis using subsurface thermal profiles and modeling to identify flow patterns and possible surface water links. We document, to our knowledge, for the first time in the literature, deep-seated cooling of the subsurface caused by extreme evaporation rates. The subsurface is cooled by 4–5 degrees Celsius below the mean annual air temperature to depths greater than 50 m, even though groundwater inflow waters are elevated by 10 degrees °C due to geothermal heating. Three thermal zones are observed along the southern edge of Salar de Atacama, with temperature dropping from 28 °C to about 12 °C over 2.5 km. A 2D numerical model of groundwater and heat flow was developed to test various hydrological scenarios and understand the factors controlling the thermal regime. Two flow scenarios at the southern margin were examined: a diffuse flow model with uniform flow and flux to the surface and a focused flow model with preferential discharge at a topographic slope break. Results indicate that the focused flow scenario matches thermal data, with warm inflow water discharging into a transition zone between freshwater and brine, cooling through evaporation, re-infiltration, and surface flow, then re-emerging near lagoons at the halite nucleus margin. This research offers valuable insights into the groundwater hydraulics in the Salar de Atacama and can aid in monitoring environmental changes causally linked to lithium mining and upgradient freshwater extraction. Full article

This work presents the design, modeling, and experimental validation of an innovative, highly autonomous, and economically viable photovoltaic solar cooker, integrating a robust battery storage system. The system combines 1200 Wp photovoltaic panels, a control block with DC/DC power converters and digital control for intelligent energy management, and a thermally insulated heating plate equipped with two resistors. The objective of the system is to reduce dependence on conventional fuels while overcoming the limitations of existing solar cookers, particularly insufficient cooking temperatures, the need for continuous solar orientation, and significant thermal losses. The optimization of thermal insulation using a ceramic fiber and glass wool configuration significantly reduces heat losses and increases the thermal efficiency to 64%, nearly double that of the non-insulated case (34%). This improvement enables cooking temperatures of 100–122 °C, heating element surface temperatures of 185–464 °C, and fast cooking times ranging from 20 to 58 min, depending on the prepared dish. Thermal modeling takes into account sheet metal, strengths, and food. The experimental results show excellent agreement between simulation and measurements (deviation < 5%), and high converter efficiencies (84–97%). The integration of the batteries guarantees an autonomy of 6 to 12 days and a very low depth of discharge (1–3%), allowing continuous cooking even without direct solar radiation. Crucially, the techno-economic analysis confirmed the system’s strong market competitiveness. Despite an Initial Investment Cost (CAPEX) of USD 1141.2, the high performance and low operational expenditure lead to a highly favorable Return on Investment (ROI) of only 4.31 years. Compared to existing conventional and solar cookers, the developed system offers superior energy efficiency and optimized cooking times, and demonstrates rapid profitability. This makes it a sustainable, reliable, and energy-efficient home solution, representing a major technological leap for domestic cooking in rural areas. Full article

The operational ability of a unit or mechanism depends mainly on the quality of the mechanically produced working surfaces. Many materials can be assigned to a group of hard-to-cut materials that includes titanium- and aluminum-based alloys, a new class of heat-resistant alloys, SiCp/Al composites, hard alloys, and other alloys. The difficulties in their machining are related not only to the high temperatures achieved on the contact pads under mechanical load and the extreme cutting conditions but also to the properties of those materials, which affect the adhesion of the chip to the tool faces, hindering chip flow. One of the possible solutions to reduce those effects and improve the operational life of the tool, and as a consequence, the final quality of the working surface of the unit, is texturing the rake face of the tool with microgrooves or nanogrooves, microholes or nanoholes (pits, dimples), micronodes, cross-chevron textures, and other microtextures, the depth of which is in the range of 3.0–200.0 µm. This review is addressed at systematizing the data obtained on micro- and nanotexturing of PCD tools for cutting hard-to-cut materials by different techniques (fiber laser graving, femto- and nanosecond laser, electrical discharge machining, fused ion beam), additionally subjected to fluorination and dip- and drop-based coatings, and the effect created by the use of the textured PCD tool on the machined surface. Full article

In complex energy storage operating scenarios, batteries seldom undergo complete charge–discharge cycles required for periodic capacity calibration. Methods based on accelerated aging experiments can indicate possible aging paths; however, due to uncertainties like changing operating conditions, environmental variations, and manufacturing inconsistencies, the degradation information obtained from such experiments may not be applicable to the entire lifecycle. To address this, we developed a stage-wise state-of-health (SOH) prediction approach that combined offline training with online updating. During the offline training phase, multiple single-cell experiments were conducted under various combinations of depth of discharge (DOD) and C-rate. Multi-dimensional health features (HFs) were extracted, and an accelerated aging probability $p_{AA}$ was defined. Based on the correlation statistics between HFs, $k_{HF}$, the SOH, and $p_{AA}$, all cells in the dataset were divided into general early, middle, and late aging stages. For each stage, cells were further classified by their longevity (long, medium, and short), and multiple models were trained offline for each category. The results show that models trained on cells following similar aging paths achieve significantly better performance than a model trained on all data combined. Meanwhile, HF optimization was performed via a three-step process: an initial screening based on expert knowledge, a second screening using Spearman correlation coefficients, and an automatic feature importance ranking using a random forest regression (RFR) model. The proposed method is innovative in the following ways: (1) The stage-wise multi-model strategy significantly improves the SOH prediction accuracy across the entire lifecycle, maintaining the mean absolute percentage error (MAPE) within 1%. (2) The improved model provides uncertainty quantification, issuing a warning signal at least 50 cycles before the onset of accelerated aging. (3) The analysis of feature importance from the model outputs allows the indirect identification of the primary aging mechanisms at different stages. (4) The model is robust against missing or low-quality HFs. If certain features cannot be obtained or are of poor quality, the prediction process does not fail. Full article

This work investigated the impact of vehicle-to-grid (V2G) cycling on the service life of lithium-ion cells, using real-world V2G data from commercial electric vehicle (EV) battery chargers. Commercially available cylindrical lithium-ion cells were subjected to long-term storage and V2G cycling under varying state of charge (SOC), depth of discharge (DOD), and temperature conditions. The ageing results demonstrate that elevated temperature (40 °C) is the dominant factor accelerating degradation, particularly at a high storage SOC (>80% SOC) and increased cycle depths (30–80% SOC, 30–95% SOC). A comparison between V2G cycling and calendar ageing over a similar storage period revealed that shallow V2G cycling (30–50% SOC) leads to comparable capacity fade to storage at a high SOC (≥80% SOC). The comparative analysis indicated that 62% of a full equivalent cycle (FEC) of V2G cycling can be achieved daily, without compromising the cell’s lifetime, demonstrating the viability of V2G adoption during EV idle/charging periods, which can offer potential operational benefits in terms of cost reduction and emissions savings. Furthermore, this work introduced the concept of a V2X capability metric as a novel cell-level specification, along with a corresponding experimental evaluation method. Full article

Based on the numerical simulation software Delft3D v4.01.00, this study established a three-dimensional water and sediment transport model for the Yellow River subaqueous delta, and simulated the water and sediment diffusion as well as erosion/deposition processes in the study area in 2019. By comparing the water discharge, sediment discharge, and deposition volume of 2019 (a year with water and sediment regulation) and 2017 (a year without water and sediment regulation), the influence of water and sediment regulation on the Yellow River subaqueous delta was explored. The results showed that water and sediment regulation projects change the distribution and diffusion of suspended sediment. Suspended sediment concentration in nearshore areas showed a significant correlation with deposition depth, particularly in the estuary area. When the water and sediment regulation was interrupted in 2017, the overall performance of the study area showed erosion, while when the water and sediment regulation was implemented in 2019, the study area exhibited sedimentation. The implementation of the water and sediment regulation project can promote the sedimentation of the subaqueous delta of the Yellow River. Full article

An integrated early warning system (EWS) for compound coastal and fluvial flooding is developed for Pyrgos, Western Greece, where low-lying geomorphology and past storm events highlight the need for rapid, impact-based forecasting. The methodology couples historical and climate-informed metocean and river discharge datasets within a numerical modeling framework consisting of a mild-slope wave model, the CSHORE coastal profile model, and HEC-RAS 2D inundation simulations. A weighted K-Means clustering approach is used to generate representative extreme scenarios, yielding more than 4000 coupled simulations that train and validate Artificial Neural Networks (ANNs). The optimal feed-forward ANN accurately predicts spatially distributed flood depths across the HEC-RAS grid using only offshore wave characteristics, water level, and river discharge as inputs, reducing computation time from hours to seconds. Blind tests demonstrate close agreement with full numerical simulations, with average differences typically below 5% and minor deviations confined to negligible water depths. These results confirm the ANN’s capability to emulate complex compound flooding dynamics with high computational efficiency. Deployed as a web application (EWS_CoCoFlood), the system provides actionable, near-real-time inundation forecasts to support local civil protection authorities. The framework is modular and scalable, enabling future integration of urban and rainfall-induced flooding processes and coastal morphological change. Full article

This study investigated the degradation of aluminum-based sacrificial anodes caused by sulfate-reducing bacteria (SRB) in marine mud. Through self-discharge tests simulating real cathodic protection conditions, alongside macroscopic observations, electrochemical analysis, and microscopic characterization, we systematically elucidated the corrosion behavior and mechanisms of the anodes with and without SRB. The results showed that the electrochemical capacity of anodes in SRB-inoculated mud was only 1281.28 Ah·kg⁻¹ (efficiency: 44.82%), failing to meet the design requirement of ≥1500 Ah·kg⁻¹. In contrast, in sterile mud, the capacity was 1972.84 Ah·kg⁻¹ (efficiency: 69.01%), which met the standard. SRB promoted the formation of discrete corrosion pits with depths reaching up to 0.43 mm, 3.07 times deeper than those observed under sterile conditions. The local pH within the pits dropped to 3–4, accelerating the selective dissolution of active elements such as Al and Zn. Mechanistic analysis revealed that the sulfides produced by SRB not only disrupt the passive film but also exacerbate the inefficient consumption of the anode through a positive feedback loop involving “acidic corrosion and electron consumption”. This led to a reduction in the protective current density, accompanied by significant fluctuations. This study provides the underlying mechanisms by which SRB degrade the performance of sacrificial anodes and valuable insights for optimizing the design of cathodic protection systems for steel structures in marine mud environments. Full article

Antarctic ice shelves regulate ice-sheet discharge and global sea-level rise, yet their rapid retreat underscores the need for new, low-cost monitoring tools. We analyze ambient seismic noise recorded by seismometers on the Pine Island Glacier ice shelf to characterize wind-induced signals and detect persistent structural resonances. Power spectral analysis shows that wind sensitivity is strongly damped compared with bedrock sites: noise increases only 5–7 dB from 0 to 25 m s⁻¹ winds, versus a 42 dB increase at an inland bedrock station, reflecting the contrasted coupling environments of floating and grounded substrates. The horizontal-to-vertical spectral ratio (HVSR) spectrograms reveal two temporally stable peaks at ~2.2 Hz and ~4.3 Hz that persist across stations and remain independent of environmental forcing. Forward modeling indicates that these peaks correspond to S-wave resonances within the ice shelf. The inferred ice-water interface depth (~440 m) agrees with the Bedmap2 thickness estimate (466 m). This work demonstrates that HVSR provides an effective passive, single-station method for measuring ice shelf thickness. Full article