Search Results (1,930)

Background: Determining the optimal duration of extracorporeal cardiopulmonary resuscitation (ECPR) remains challenging, as patient outcomes may vary significantly based on individual characteristics. We aimed to establish critical time thresholds for achieving favorable neurological outcomes with ECPR across different risk groups, potentially providing more tailored guidance for clinical decision-making. Methods: This single-center retrospective study screened 279 adult patients who received ECPR between 2013 and 2020. Through multivariate analysis of various clinical parameters, we developed a pragmatic bedside risk stratification framework to identify groups with different prognostic profiles. The primary outcome was neurological status at discharge, assessed by the Cerebral Performance Categories scale. Results: In multivariate analysis, age greater than 50 years with asystole (adjusted odds ratio [OR]: 4.89, 95% confidence interval [CI]: 1.41–17.00) or pulseless electrical activity (adjusted OR: 9.70, 95% CI: 2.80–33.60), aspartate transaminase (adjusted OR: 1.52, 95% CI: 1.15–1.99), creatinine (adjusted OR: 2.08, 95% CI: 1.30–3.34), initial lactate (adjusted OR: 1.88, 95% CI: 1.27–3.45), and low-flow time (adjusted OR: 3.50, 95% CI: 2.02–6.06) were associated with poor neurological outcomes. Based on these findings, we identified three distinct risk groups showing different acceptable low-flow time thresholds: low-risk (38 min), moderate-risk (27 min), and high-risk (20 min). Notably, no favorable neurological outcomes were observed beyond 70 min in the low-risk group and 90 min in moderate/high-risk groups. Risk group stratification effectively predicted neurological outcomes across different low-flow time intervals. Conclusions: Risk-stratified evaluation of low-flow time (cardiac arrest to ECMO pump-on) provides clinically relevant thresholds for different patient groups, suggesting that continuation of ECPR may be warranted in low-risk patients even with extended low-flow times. This approach may enable more personalized decision-making in ECPR implementation. Full article

This paper presents the results from in-lab chassis dynamometer testing of two battery electric vehicles of the same make and model: a 2022 model year vehicle with a heat pump and a 2020 model year vehicle with a resistive positive temperature coefficient (PTC)-type heater. The vehicles were tested over a series of standard drive cycles at −10 °C, −7 °C, 0 °C, and 25 °C to determine the impacts of the different heating systems on vehicle energy consumption and driving range in cold temperatures. The results indicate that in most (but not all) heating situations the heat pump heated its vehicle’s cabin more efficiently than the PTC heater did, especially at 0 °C. At the lowest temperature, −10 °C, the heat pump used more energy than the PTC heater on cold-start but was more efficient than the PTC heater once the cabin was warmed up. Over standard drive cycles and using SAE J1634 calculation methods to obtain a single range value for each cycle type, the improvement in the percentage of driving range retained by the heat pump-equipped vehicle over the PTC heater-equipped vehicle varied between 1% and 15% depending on ambient conditions and drive cycle, with the average advantage in percentage range retained being 7% over the UDDS cycle, 7% over the HWFET cycle, and 4% over the US06 cycle for all cold temperatures combined. Full article

Electric vehicles (EVs) experience substantially reduced driving range in cold weather, primarily due to cabin heating energy demands. This paper proposes a control allocation strategy for positive temperature coefficient (PTC) heater-based electric minibus cabin thermal management, aimed at minimizing energy consumption. The strategy is of a hierarchical structure, where a supervisory PI cabin temperature controller commands the heating power demand, which is then achieved through optimal allocation and low-level control of the cabin inlet air temperature, coolant pump flow, and radiator blower air flow control inputs. Based on the assumption of fast heating system dynamics relative to cabin thermal dynamics, quasi-steady-state optimization of control input allocation is carried out by employing a grid-search algorithm over a dataset resulting from high-fidelity simulations. For the system heat-up transient conditions, where the steady-state allocation proves to be suboptimal, dynamic programming is applied on a validated reduced-order model to optimize the control trajectories. Insights gained through control trajectory optimization are then used to develop a rule-based modification of the control allocation strategy for the heat-up scenario. Simulation verification of the overall control system demonstrates energy consumption reduction in the range from 4 to 12% when compared to the industrial baseline system across both steady-state and transient operating conditions. Full article

Jordan is among the most water-stressed countries globally, with renewable freshwater availability falling below 100 m³ per capita per year. The Jordan Valley (JV), the country’s primary irrigated agricultural corridor, faces interconnected pressures across water, energy, food, and ecosystem (WEFE) systems under intensifying climatic and demographic stressors. This study evaluates the integrated performance of the WEFE nexus in the Jordan Valley using updated evidence (2018–2023) to quantify cross-sector interactions, performance gaps, and intervention priorities. A mixed-methods empirical assessment integrated quantitative sectoral data on water supply–demand and quality, electricity supply–demand and renewable deployment, agricultural productivity, and ecosystem pressure indicators, complemented by Living Lab–based stakeholder interviews. Sectoral indices were calculated based on supply–demand adequacy and aggregated into an overall WEFE Nexus Index. Results indicate persistent water scarcity, with a domestic supply of 23.48 MCM yr⁻¹ versus demand of 26.00 MCM yr⁻¹ (deficit −2.52 MCM yr⁻¹) and irrigation supply of 206 MCM yr⁻¹ relative to approximately 400 MCM yr⁻¹ demand (deficit −194 MCM yr⁻¹). Water services account for 14% of national electricity consumption, while solar pumping provides approximately 40% of daytime irrigation energy. Agricultural productivity is constrained by salinity and water quality, resulting in yield gaps (e.g., greenhouse vegetables: 4.7 vs. 10.0 t/dunum). Sectoral performance is uneven (Water 0.71; Energy 1.00; Food 0.45; Ecosystem 0.50), yielding an overall WEFE Nexus Index of 0.63 (0.50 after efficiency adjustment). Climate projections indicate continued warming (+1.8 °C) and declining precipitation (−11%) by 2060. Water harvesting, integrated renewable-powered water services, wastewater reuse, salinity management, climate-smart agriculture, and ecosystem restoration are critical to enhancing climate-resilient resource security in the Jordan Valley. The WEFE index developed here offers a tool for integrated planning and underscores that achieving climate-resilient resource security in the Jordan Valley will require strategic, cross-sector interventions and adaptive governance rather than sector-specific fixes. Full article

Many countries rely on coal for energy security during renewable transitions. This study conducts a technical, economic, and environmental analysis of hybridizing a supercritical coal-fired power unit with photovoltaics (PV) to create a sustainable hybrid system at a plant in Silesian Voivodeship, Poland. The goal is to assess costs and optimal operating conditions for a coal–PV hybrid under varying scenarios, using a decision-support model that integrates fuel prices, CO₂ emission charges (EUA), and technical parameters. Two main scenarios are modeled. In auxiliary-only PV (112 MW system), real-time power supplies pumps and fans, cutting coal consumption without storage; LCOE decreases with annual hours (2800–7000), outperforming conventional coal across EUA prices (20–50 EUR/t). In PV surplus export, excess generation (1300 h/year) is grid-fed for revenue, amplifying LCOE reductions—hybrid superiority emerges above 34 EUR/t EUA, per equivalence thresholds. Results show coal electricity exceeds low-emission costs above 34 EUR/t CO₂, with maximum disparity at 50 EUR/Mg. The hybrid leverages existing infrastructure, mitigates solar intermittency via auxiliary supply, ensures baseload continuity, boosts flexibility, and prolongs asset life—reducing >123,000 EUA/year at 145,000 MWh PV output. This sustainable hybrid promotes energy transition, reduces fossil fuel dependence, and aligns with global sustainability goals. Full article

This study benchmarks renewable energy source (RES) utilization in the Visegrad Four (V4) against the EU average using Eurostat data for 2014–2022. A multi-layer framework was used to combine technology-specific per-capita indicators, sectoral RES shares, cluster analysis, and panel regression with fixed effects. The EU substantially exceeds V4 in hydropower (774.06 vs. 270.19 kWh/person), wind (972.06 vs. 161.30 kWh/person), and solar technologies. The electricity-sector gap is most pronounced (EU 41.17% vs. V4 18.69%). Paired t-tests confirmed a statistically significant persistent gap (t(8) = −20.78; p < 0.001), consistent with delayed convergence. Cluster analysis assigned all V4 countries to a single moderate-RES tier, structurally separated from Western and Nordic clusters; panel regression confirmed that the V4 coefficient was robustly negative (β = −5.783 to −9.088 pp) even after policy controls, with fossil lock-in (β = −2.404 pp) emerging as the most consistent structural determinant, whereas V4 × fossil lock-in interaction was positive (β = +2.558 pp), suggesting partial mitigation through differentiated pathways. Intra-V4 heterogeneity—Slovakia’s hydropower lock-in, Hungary’s wind prohibition, Poland’s coal dependency, and Czech Republic’s curtailed feed-in tariff—argues against homogeneous policy responses; results support technology-specific strategies (wind/solar PV in Poland/Czech Republic; solar thermal/heat pumps in Hungary/Slovakia) and grid modernisation as cross-cutting priority. Full article

Samothrace is a Greek island in the northern Aegean Sea. Though connected to the mainland grid and demonstrating strong wind potential, it is challenged by seasonal shortages in both electricity and potable water. This study assesses a Hybrid Renewable Energy System designed to meet local energy and water demands while maintaining economic viability. The system consists of 10 wind turbines (23.5 MW), a reverse osmosis desalination plant yielding 876,000 m³/year, and four alternative storage configurations: green hydrogen, pumped hydro, lithium-ion batteries, and a combined green hydrogen–pumped hydro option. Using identical climatic and demand data, system performance was simulated for the years 2011–2020. Wind generation reached 113,000 MWh annually, of which 81–84% was exported to the mainland. Potable water demand was met at a rate of 99% in all scenarios, with monthly production ranging from 17,500 m³ in February to almost 50,000 m³ in August, thus requiring 1.80% of wind output. Investment costs ranged from 34.4 M € to 39.8 M €; net present values remained around 75 M € for all scenarios. Results demonstrate that complete autonomy can be achieved; however, economic sustainability is maximized by leveraging the interconnection and sizing storage below full-autonomy levels. Full article

Dual-source heat pump systems combining photovoltaic-thermal (PVT) and air-source technologies have attracted considerable research interest due to their energy complementarity. Based on the climatic characteristics of the Dalian region, this study conducted field measurements and data analysis on a developed dual-source heat pump system incorporating three adaptive operational modes: (1) PVT mode, (2) PVT/air dual-source mode, and (3) photovoltaic (PV)/air-source mode. Compared to Mode (3), Mode (1) achieves a 5.76% higher heating capacity and an 11.56% greater electrical efficiency. Meanwhile, Mode (2) demonstrates a 12.23% increase in heating capacity, and a 9.14% improvement in electrical efficiency relative to Mode (3). A data-driven methodology is provided to quantify the system’s evaporation temperature, the thermal efficiency of PVT mode, and the coefficient of performance (COP) of the PVT heat pump. The economic assessment demonstrates that the proposed dual-source heat pump system achieves a heating cost as low as RMB 0.1125/kWh and a payback period of 6.4 years, indicating favorable economic benefits. This study provides fundamental data and computational methods for the optimized operation of the PVT/air dual-source heat pump. Full article

Small-scale prosumer installations are playing an increasingly important role in the Polish electricity sector. These primarily include photovoltaic systems and heat pumps installed for internal use. Noticeable losses for individual investors, generated by the power flow mechanism during peak production hours (connection to the grid) and peak demand (drawback from the grid), as well as the issue of fluctuating grid capacity and the observed redispatch procedures for photovoltaic installations, are driving increased interest in equipping home energy installations with energy storage systems, strengthening the aspect of sustainable energy development in this dimension. The impact of energy storage on investment motivation and the actual effects of incorporating it into home energy installations have not yet been sufficiently researched, particularly in Poland. Therefore, the aim of the study was to assess the use of energy storage in home installations as a socio-technical direction of power development at the micro level, in light of the constantly increasing energy demand observed worldwide in line with the challenges of sustainable development. The results of a survey of 206 individual users of power installations equipped with energy storage systems in Poland were used for this study. The research was qualitative and quantitative in nature, with descriptive statistics and a logistic regression model used in the in-depth section, and the findings were supported by PQStat software. The research revealed that the selection of energy storage systems in home power grids is related to the potential for prosumer optimization. On the other hand, they are seen as a path towards increasing energy security at the household level. Supporting this direction of installation development at the micro level is a justified concept for the development of green energy in Poland, socially and environmentally beneficial as well as economically justified, i.e., in line with the trend of sustainable development. The information campaign, combined with financial support for this type of investment, should be continued and strengthened in Poland. Full article

Conventional thermoelectric generators (TEGs) suffer from thermal resistance introduced by ceramic substrates and thermal interface materials, which limits the achievable temperature gradient across the junctions and reduces conversion efficiency. To overcome this limitation, a pin-fin integrated thermoelectric device (iTED) is proposed, in which the hot-side heat exchanger is incorporated directly into the hot-side interconnector, eliminating the ceramic and associated greases. An explicitly coupled thermal-fluid-electric finite-volume model is developed in ANSYS Fluent’s user-defined scalar (UDS) environment to quantify the simultaneous thermal-fluid-electric behavior of the iTED for inlet temperatures of 350 $\le T_{\mathrm{in}}\mathrm{K}\le$ 650, Reynolds numbers of 3000 $\le \mathrm{Re}\le$ 15,000, and load resistances ranging from 0.01 to ${10}^6$% of the internal device resistance ($R_{\mathrm{int}}$), for a fixed cold-side temperature of 300 K. The model is validated against established tube-bank correlations (2.2% agreement in pumping power) and a one-dimensional Explicit Thomson Model (1.2–6.9% agreement across all electrical system response quantities). Compared with an equivalently sized conventional TEG, the iTED achieves a 4.6-fold higher maximum power output (23.9 [W] vs. 5.2 [W] at Re = 15,000), a 2.8-fold higher thermal conversion efficiency (8.1% vs. 2.9%), and a 4.8-fold higher performance index (7.8 [-] vs. 1.6 [-] at Re = 3000), all at $T_{\mathrm{in}}$ = 650 K. A performance index analysis reveals that lower Reynolds numbers and higher inlet temperatures maximize the net power benefit, delineating the operational envelope in which the iTED produces more electrical power than is needed for fluid pumping. These findings demonstrate that device-level restructuring—specifically, the elimination of interfacial thermal resistance via integrated pin-fin heat exchangers—can yield performance improvements comparable to or exceeding those achievable through material advances alone. Full article

Wastewater treatment plants (WWTPs) are among the most energy-intensive components of urban infrastructure. In light of the revised EU directive on municipal wastewater treatment, which targets energy neutrality by 2045, effective energy management in this sector is becoming essential. This article reviews the current knowledge regarding energy consumption in WWTPs and analyses opportunities to increase their energy self-sufficiency by reducing energy demand and recovering energy. Key factors influencing energy consumption are discussed, including facility size, the range of technological processes used, automation level, and equipment condition. Attention is given to aeration systems, which account for the largest share of electricity consumption, and the possibilities for their modernization and optimization using energy-efficient diffusers and advanced process control systems. The potential for recovering chemical energy from sewage sludge is analyzed, with emphasis on anaerobic digestion and co-digestion with other organic wastes. Alternative sludge conversion methods, such as incineration, pyrolysis, gasification, and hydrothermal carbonization, are also presented. The analysis is complemented by technologies for recovering physical energy from wastewater, including the use of thermal energy via heat pumps and hydraulic energy from wastewater flow. The findings indicate that achieving energy self-sufficiency in WWTPs requires site-specific, hybrid solutions combining energy savings with selective energy recovery, considering technical and economic conditions. Full article

This paper presents the design and analysis of solar systems for agricultural applications and the sustainable energy supply of villages, based on a case study of a rural settlement comprising 30 households. The village energy demand is quantified through a detailed assessment of hourly load profiles for daytime and nighttime operation, identifying peak loads and total daily energy consumption. Energy usage patterns are established for residential buildings, agricultural water pumping, public lighting, healthcare facilities, and commercial services. To meet these energy requirements sustainably, a 60 kW photovoltaic (PV) system is proposed in combination with a solar thermal water heating system designed to supply domestic and agricultural hot water. This study details the design methodology and simulation of the solar thermal system, including heat transfer modeling and system dimensioning. MATLAB (V.22b) simulations are conducted to evaluate system performance, covering PV energy generation, battery charge–discharge cycles, and thermal behavior over a 24 h period. Comparative analyses of standalone PV, hybrid PV/T, and combined PV and solar thermal configurations demonstrate that separate PV and thermal systems provide superior cost-effectiveness, operational reliability, and reduced maintenance requirements. The results confirm the technical feasibility, economic viability, and environmental benefits of solar-based solutions for rural electrification and agricultural applications. The results indicate that the analyzed rural settlement has an estimated daily electricity demand of approximately 590 kWh. Based on this demand, a 60 kW photovoltaic system was selected to ensure sufficient daytime electricity production while also allowing battery charging for nighttime consumption. In addition, the solar thermal system can increase the water temperature from approximately 10 °C to 55–80 °C, depending on solar irradiance conditions. The combined PV and solar thermal configuration demonstrates the potential to provide a reliable and sustainable energy solution for rural off-grid communities. Full article

The increasing frequency of torrential rainfall due to global warming has resulted in a significant rise in urban flooding and river overflows. Rainwater pumping stations, typically located near rivers, serve as buffers between sewer systems and receiving water bodies, helping to mitigate flood risks. A primary challenge in operating these stations is optimizing pump performance to prevent flooding while minimizing energy consumption and costs. Various computational methods, including meta-heuristics and deep learning, have been proposed to tackle this optimization problem. However, most studies either overlook or inadequately address pump maintenance costs, which are essential for long-term operational efficiency. This gap stems from the lack of a comprehensive model that accurately captures the full spectrum of costs involved in pump operation. This paper introduces a cost estimation model that integrates both deterministic and probabilistic elements to enhance the energy-efficient operation of rainwater pumping stations. The model focuses on pumps with capacities of 100 m³/min and 170 m³/min, which are commonly used. It takes into account electricity consumption costs as well as maintenance costs arising from frequent on/off cycles and dry-run events. Predictions of failures due to these operational stresses are modeled using the Crow–AMSAA non-homogeneous Poisson process (NHPP) and Weibull distributions—probabilistic models widely used in mechanical failure analysis. To evaluate the proposed model, simulations were conducted using the Storm Water Management Model (SWMM), comparing a deep reinforcement learning-based control strategy with the current operational method at the Gasan Pumping Station in Seoul, South Korea. The pump operating costs associated with each method were calculated and analyzed using the proposed model, demonstrating its potential for ensuring cost-effective and reliable pump operation. Full article

Multi-regional electricity markets increasingly struggle to balance data privacy requirements with the computational burden of centralized clearing. To address this issue, this study proposes a distributed joint-clearing framework based on the Alternating Direction Method of Multipliers (ADMM) to co-optimize pumped storage hydropower (PSH) and battery energy storage systems (BESS) across energy, frequency regulation, and reserve markets. A mixed-integer programming model is formulated to maximize social welfare, explicitly capturing the time-coupled, energy-oriented characteristics of PSH and the fast-response, power-oriented capabilities of BESS. The global problem is decomposed into regional subproblems that can be solved in parallel. An adaptive penalty parameter strategy is further introduced to dynamically balance primal and dual residuals, thereby improving convergence and robustness in the mixed-integer setting. To address the limited economic interpretability of dual variables in mixed-integer programming (MIP) models, an approximate marginal pricing mechanism based on subproblem sensitivity analysis is proposed. A two-region, 24 h case study shows that the proposed method converges in around 65 iterations and achieves a social welfare outcome within 0.61% of the centralized optimum. By minimizing information exchange, the framework offers a scalable and privacy-aware solution for future multi-regional market operations involving heterogeneous energy storage resources. Full article

This review deals with the development and progress of micro-electromechanical systems (MEMS) actuators, which are needed in microfluidic applications, such as lab-on-a-chip and diagnostics. In the last 10 years, there have been tremendous advances in materials, microfabrication and computational modeling that have increased the functionality and scope of MEMS-based microfluidic actuation. This study classifies MEMS actuators on the basis of the physical method of actuation, including electrostatic, piezoelectric, and pneumatic actuation designs, in comparison with their application in pumping, valving, and droplet control. It examines the suitability of emerging structural and functional materials, such as piezoelectric thin-films and electroactive polymers, paying special attention to their reliability and biocompatibility. It also highlights the progress in multiphysics modeling that incorporates electrical, thermal, mechanical, and fluidic models, which facilitates the efficient design and performance optimization procedures. Other trends are multifunctional actuators with built-in sensing capability and the use of artificial intelligence (AI)-assisted design in production. With these developments, however, there exist issues of power efficiency, thermal control, fabrication uniformity and operational durability, and also the absence of standardized benchmarking. Finally, future research directions are outlined, including hybrid MEMS actuation, intelligent microfluidic operations, to improve the performance of the system and enable the transfer of the lab demonstrations to the large scale application of the system. Full article