Search Results (1,211)

In this study, a three-dimensional simulation of a walking-beam reheating furnace was developed to improve the steel slab reheating process and reduce surface oxidation kinetics using computational fluid dynamics (CFD). Combustion, heat transfer, fluid dynamics, and chemical reaction models were integrated into the numerical framework of this study. In addition, dynamic mesh remeshing was coupled through user-defined functions (UDFs), enabling the simultaneous simulation of slab movement and evolution of the involved transport phenomena. Turbulence was modeled with the realizable k-ε formulation, combustion with the Eddy Dissipation model, and radiation with the P-1 model coupled with WSGGM to include CO₂ and H₂O gas radiation. Scale formation was modeled using customized functions based on Arrhenius-type kinetics and Wagner’s oxidation model, evaluating its growth as a function of time, temperature, and furnace atmosphere. The predicted thermal evolution inside the furnace was validated using industrial data, yielding an average deviation of 5%. Furthermore, the proposed operating conditions led to an average slab temperature of 1289.77 °C at the exit of the homogenization zone, which was 16 °C higher than that under the current operation but still within the target range (1250 ± 50 °C). The reduction in combustion air decreased energy losses and improved product quality, lowering the molar oxygen content in the furnace atmosphere from 4.9 × 10² mol to 6.7 × 10¹ mol. Additionally, annual savings of 4,793,472 kg of natural gas and 13,884 tons of steel were estimated owing to reduced oxidation losses. The proposed air–fuel adjustment led to estimated annual energy savings (equivalent to 4,793,472 kg of natural gas) and a reduction in material loss due to oxidation from 4.5% to 3.75% (an absolute reduction of 0.75 percentage points; relative reduction ≈ 16.7%), which has a significant industrial impact on metal conservation and descaling cost reduction. Although there are CFD studies on plate overheating and scale growth separately, this work presents three main contributions: (1) the integration, within a single numerical framework, of combustion, radiation, species transport, oxidation kinetics, and actual plate movement using a dynamic mesh; (2) validation against continuous industrial records (16 thermocouples) and quantification of operational benefits such as fuel savings and reduced material loss; and (3) a comparative analysis between actual and optimized conditions, which standardize the air–methane ratio. Full article

This study addresses the critical challenge of optimizing outdoor thermal comfort for the aging population in old residential communities within China’s Hot-Summer and Cold-Winter (HSCW) climate zones. Against the backdrop of urban regeneration and rapid demographic aging, it investigates how key landscape elements—Square Reflectance, Greening Type, and Pergola Condition—influence the microclimate of community public spaces. The research employed an integrated methodology centered on numerical simulation. Using the ENVI-met 5.9.0 software and an L₉(3⁴) orthogonal experimental design, it simulated the microclimatic effects of nine combined scenarios on typical summer and winter days for a case study in Nanjing. The comprehensive thermal comfort index, Physiological Equivalent Temperature (PET), was used as the primary evaluation indicator to assess the thermal comfort performance for elderly occupants, with the assistance of air temperature, wind speed, and relative humidity, and the results were analyzed via range analysis and ANOVA. The key findings indicate that: (1) Greening Type and Pergola Condition are the dominant factors affecting microclimate and annual thermal comfort across seasons, while Square Reflectance has a comparatively minor influence. (2) The combination of deciduous trees with lawn achieves the optimal cross-seasonal PET gain. It provides effective shading and cooling in summer while allowing beneficial solar penetration for warming in winter, substantially outperforming evergreen-dominated configurations. (3) The presence of a pergola consistently enhances comfort by providing essential shade in summer and acting as a windbreak in winter. The combination dominated by deciduous trees + lawn and pergola yields an overall PET gain 1.097 °C higher than that of evergreen trees + shrub without pergola. This study provides evidence-based, elderly specific landscape design strategies to inform the thermal environment optimization of public spaces in old residential areas undergoing renewal. Full article

The pursuit of carbon neutrality demands advanced low-carbon energy processes and their effective integration into building systems. Ground-source heat pumps (GSHPs) offer a key pathway for decarbonizing heating, yet their cold-climate application is compromised by soil thermal imbalance, which degrades their long-term efficiency. This study proposes and evaluates an innovative air-assisted GSHP system that integrates a vegetable greenhouse with a zoned borehole configuration for seasonal thermal storage to achieve carbon neutrality. The system segregates boreholes into core and peripheral zones to establish a controlled soil temperature gradient, enabling cascaded heat storage and thermal optimization. A comprehensive year-long field test was conducted on a residential building in Harbin, China. The results demonstrate that the system reliably maintains comfortable indoor conditions during severe winters, achieving average seasonal COPs of 3.82 for the heat pump unit and 2.85 for the overall system. The zoned operation strategy successfully generated a significant intra-field soil temperature gradient, with a maximum differential of 5.9 °C between the core and peripheral boreholes during charging. The measured heat extraction-to-storage ratio was 0.598, confirming effective cascaded utilization. From an environmental perspective aligned with low-carbon energy technologies, the system achieves annual savings of 8.66 tons of standard coal and a net CO₂ reduction of 1.3 tons when accounting for regional grid carbon intensity. This research provides empirical validation and practical design guidance for implementing efficient GSHP systems in severely cold regions, thereby contributing substantively to building sector decarbonization. Full article

This study aimed to evaluate and compare the effects of HS on sow reproductive performance using 11 different thermal indices calculated from environmental data in a temperate climate. Reproductive records, including live-born piglets, stillbirths, and mummified fetuses per litter, were obtained using farm management software. The overall means for live-born piglets, stillbirths, and mummified fetuses per litter from January to December 2023 were 13.7, 1.06, and 0.45, respectively, whereas the temperature, relative humidity, and air velocity were 24.08 °C, 63.70%, and 3.2 m/s, respectively. Temperature–humidity index (THI): THI2 and THI6 were significantly associated with the number of live-born piglets (p < 0.001) and mummified fetuses (p < 0.05) per litter, with optimal reproductive outcomes observed at values below 74. THI1 was significantly associated with the number of stillborn piglets (p < 0.05). Based on the Akaike information criterion (AIC) values, THI6 provided the best overall fit for evaluating the effects of HS on reproductive performance. Reproductive outcomes in sows respond to trait-specific thermal signals. THI2, THI6, and THI1 are recommended for assessing HS-related reproductive outcomes in sows raised under temperate climatic conditions. Full article

Zn-TiO₂ composites were synthesized via a hydrothermal method, and their photocatalytic performance was optimized using an orthogonal design. Among the factors of hydrothermal temperature, reaction time, and Ti/Zn molar ratio, hydrothermal temperature showed the most significant influence on the photocatalytic performance of Zn-TiO₂. The Zn-TiO₂ obtained under the optimal conditions (120 °C, 10 h, and a Ti/Zn molar ratio of 100:5) exhibited the best photocatalytic performance, with a 26% improvement in the photocatalytic degradation efficiency of Rhodamine B (RB) compared to pure TiO₂ under identical conditions. The composition, morphology, and structure of the Zn-TiO₂ photocatalysts were characterized by XRD, SEM-EDS, N₂ adsorption–desorption, and XPS, thereby enabling analysis of the mechanism for the enhancement of its photocatalytic performance. In this work, air-entrained composite mortar (ACM) with a double-layer structure was designed as a contrast to conventional cement mortar (CM). Novel green building materials with pollutant-degradation capability were developed by loading Zn-TiO₂ and TiO₂ photocatalysts onto these different mortar surfaces. Photocatalytic tests and cyclic aging experiments demonstrated that the Zn-TiO₂/ACM achieved the superior degradation effect on the RB solution and maintained good catalytic stability. These findings suggest broad application prospects in the field of green building materials. Full article

Sandwich materials are increasingly used due to the possibility of improving their combined properties. However, some manufacturing operations become more complex, such as drilling, where it is more difficult to determine the optimal cutting conditions that provide the appropriate hole quality. In this context, the quality of the drilled holes of the carbon fiber plates with a foamed polyvinyl chloride core, a material used in marine environments at very low temperatures, among others, is analyzed. Due to the importance of surface quality in operations prior to the assembly of plates and the influence of delamination on the in-service behavior of materials, the objective is to determine the diameter deviation (∆D), circularity (CIR), and delamination (FD) at the entrance and exit of the hole after drilling plates of this material. This sandwich material has been drilled at low temperatures (−15, 0, and 15 °C) using compressed air as cooler. Different cutting conditions have been used regarding rotation speed and feed. An experimental and statistical study, including a response surface optimization for FD, and multiple response surface optimization for ∆D and CIR were used. Several ranges of suitable cutting conditions can be identified for each temperature. Full article

To address the critical need for accurate human thermal comfort prediction in winter heating environments, this study established a comprehensive thermal comfort dataset containing 2089 valid samples through experiments. On this basis, thermal comfort prediction models were constructed using three multi-class machine learning algorithms: Support Vector Classification, K-Nearest Neighbors, and Random Forest. The predictive performance of 63 different feature combinations was systematically evaluated. The results indicate that the feature subset comprising indoor air temperature, forehead temperature, cheek temperature, dorsal hand temperature, heart rate, and systolic blood pressure yields the optimal prediction performance. Among the evaluated models, the Random Forest model demonstrated superior overall performance, achieving an accuracy exceeding 90% and an AUC ranging from 96% to 99%, significantly outperforming the SVC and KNN models. Compared with the traditional Predicted Mean Vote (PMV) model, the machine learning models developed in this study showed a substantial improvement in prediction accuracy under identical conditions; notably, the Random Forest model improved accuracy by approximately 40% over the PMV model. Based on these findings, a smart heating system framework integrating environmental sensors, wearable devices, and intelligent control valves is proposed, providing a theoretical basis and technical approach for realizing personalized and energy-efficient heating control. Full article

This study explored a range of cooling interventions suitable for city laneways where space for greening opportunities is constrained. Five individual cooling interventions namely, PVC shading, cool pavement, small canopy trees, green wall and water mist, as well as multiple combinations of these individual cooling interventions were tested in a narrow laneway in the temperate setting of Melbourne, Australia. The impact of various cooling interventions was assessed by evaluating microclimatic parameters—air temperature (T_a), relative humidity (RH), mean radiant temperature (T_MRT)—alongside two thermal comfort indices, Physiological Equivalent Temperature (PET) and Universal Thermal Climate Index (UTCI). When each intervention was analysed individually, water mist was the best performing with T_a, PET and UTCI reduction. This was followed by PVC shading, small canopy trees and green walls. Cool pavement had the lowest T_a reduction and minimal thermal comfort impact. While green provided marginal reductions in thermal comfort indices, the effects were insufficient for standalone cooling. They were most effective when integrated with other cooling interventions. For example, when green walls were combined with water mist, a T_a reduction of 1.49 K and a T_MRT reduction 2.57 K were obtained. The water mist system as an individual cooling intervention or as part of a combined intervention had an impact on T_a with a reduction of maximum 1.3 K and 1.76 K, respectively. The water mist had a UTCI reduction of 1.25 K, and the water mist combined with green wall had a PET reduction of 1.84 K. The novel contribution of this study to climate-sensitive urban design is the suite of practical, site-specific interventions for extreme summer conditions. These findings provide a framework for planners and designers to evaluate and implement optimal cooling strategies tailored to the unique microclimate demands of narrow urban laneways. Full article

In cold regions with prolonged subzero temperatures and abundant solar radiation, Trombe walls serve as high-efficiency passive solar building envelopes for improving indoor thermal comfort. This study aims to optimize the thermal performance of Trombe walls via a multimodal data analysis framework and a multiview measurement algorithm. Three distinct Trombe wall configurations were constructed and continuously monitored for 60 consecutive days under typical winter conditions (average temperature: −15 °C; solar radiation intensity: 800–1100 W/m²). Field-measured datasets, including solar radiation intensity, hourly air temperature distribution, and heat exchange efficiency, were systematically analyzed to quantify the impacts of ventilation mode, air gap width, and insulation thickness on thermal performance. The results demonstrate that the hourly peak surface temperature of the optimized Trombe wall reaches 25.7 °C at 13:00, which significantly improves indoor thermal comfort compared with conventional buildings. An air gap width of 6 cm minimizes indoor temperature fluctuations (fluctuation coefficient = 0.08), while a 20 mm insulation layer stabilizes heat loss reduction at 31.1% relative to non-insulated walls. The optimal operational parameter combination (6 cm air gap, 16 °C indoor set temperature) was determined based on the lowest temperature fluctuation and highest thermal efficiency, with experimental results deviating by less than 5% from established analytical models. This study verifies the reliability of the multimodal data analysis framework for Trombe wall performance evaluation, providing practical design guidelines for passive solar building envelopes in cold regions. Full article

Wood products made from Manchurian ash are widely used as furniture and decorations, particularly waterborne-coated Manchurian ash (Fraxinus mandshurica Rupr.). However, while waterborne coatings offer less air pollution, their odor emission dynamics under different environmental conditions remain poorly understood. To address these gaps, this study systematically analyzed 28-day volatile organic compounds (VOCs) and very volatile organic compounds (VVOCs) release profiles under controlled temperature, relative humidity, and air exchange rate-to-loading factor ratios (AER/Ls), using thermal desorption–gas chromatography–mass spectrometry/olfactometry (TD-GC-MS/O). Eighteen key odor-active compounds (OACs) were identified, comprising 11 wood-derived and seven coating components, exhibiting eight odor attributes: disinfectant-like, aromatic, tobacco-like, unpleasant, vinegar-like, flowery, sweety, and alcohol-like. The dominant attributes were disinfectant-like and aromatic. The results showed that temperature accelerated release rates and shortened equilibrium time, while increasing concentrations and odor intensity. Relative humidity prolonged equilibrium, with stage-dependent concentration effects, yet consistent odor intensity rise. Higher AER/L reduced equilibrium time and concentrations through dilution-dominated dynamics despite accelerated release rates from increased pressure differentials. These findings indicated that synergistic high-temperature (40 °C)/high-humidity (60% RH) conditions accelerate odorant emission, while optimized ventilation (AER/L 0.5 m³·m⁻²·h⁻¹) ensures effective mitigation. The findings will inform strategies to reduce odor impact and advance eco-efficient finishing technologies for wood products. Full article

Dissolved-air flotation (DAF) is widely used for surface-water pretreatment but remains insufficiently explored for chemically complex groundwater. This study develops a thermodynamic and bubble-dynamics modeling framework to evaluate the feasibility of DAF pretreatment for groundwater containing elevated arsenic, natural organic matter (NOM), and color. The study is theoretical and model-based; no experimental dissolved-air flotation tests were performed. Air solubility was calculated at pressures of 4–6 bar and temperatures of 13–17 °C, while microbubble size, rise velocity, and bubble–floc interaction efficiencies were estimated using established physical models. Laboratory coagulation–flocculation jar tests with FeCl₃ and FeCl₃/PAC were used to define realistic floc properties prior to flotation modeling. No experimental dissolved-air flotation tests were conducted; all flotation-related results presented in this study are derived from thermodynamic and hydrodynamic modeling. Results show that a temperature decrease from 17 to 13 °C increases effective gas supersaturation by ~15% and shifts predicted microbubble diameters from ~60–90 µm to ~35–60 µm under identical operating conditions. The qualitative consistency between modeled flotation-relevant parameters and previously observed coagulation–flocculation trends for color, total organic carbon, and arsenic removal supports the proposed mechanistic framework. The study demonstrates how coupling coagulation chemistry with thermodynamically optimized air dissolution can enhance DAF applicability for arsenic- and NOM-rich groundwater. Full article

The different Assisted Reproductive Technology techniques are offering hope to millions of couples struggling with infertility. However, the success of IVF/ICSI is related at least partially to the optimization of embryo culture conditions, which are influenced by myriad of physiological and environmental factors. This review reports the latest advancements in embryo culture techniques, with a particular focus on the roles of oxygen tension, pH regulation, temperature stability, air quality in enhancing embryo viability, competency and implantation rates. In addition, we explored the critical importance of quality assurance (QA) factors and key performance indicators (KPIs) to keep laboratory efficiency. We highlighted also some emerging technologies, such as dynamic culture systems, metabolomics, proteomics biomarkers potential, and artificial intelligence (AI) in embryo selection and monitoring, which hold promise for further improving embryo culture techniques. By providing a comprehensive overview of the current state of embryo culture optimization, this review aims to guide future research and clinical practices in the field of assisted reproductive technology (ART). Full article

Coffea canephora cultivation areas in Brazil are frequently exposed to successive cycles of water deficit, triggering plant stress responses. In addition to water deficit, increased air temperature can act as a second stress factor. The recurrence of these stress factors may induce plant tolerance mechanisms, potentially mitigating future stress responses even of a different stress nature. We hypothesized that repeated cycles of water deficit can trigger tolerance mechanisms that make C. canephora leaves more resilient to supra-optimal temperatures. To test this hypothesis, young C. canephora plants were grown under non-limited water conditions for seven months (Ψ_mSoil > −20 kPa), after which they were subjected to two consecutive cycles of water deficit (Ψ_mSoil < −300 kPa), followed by rehydration. Two clones were used, ‘A1’ and ‘3V’, previously classified as drought sensitive and tolerant, respectively, considering the dynamics of physiological and architectural responses. After the second cycle, leaf discs were collected from completely expanded leaves formed during the two stress cycles and exposed to heat treatments (35 °C, 40 °C, 45 °C, 50 °C, and 55 °C) for 15 min in a water bath. Chlorophyll a fluorescence emission was then monitored, and the results were analyzed using OJIP transient kinetics and the JIP_Test. High temperatures induced negative changes in both OJIP kinetics and JIP_Test-derived parameters. A significant increase in F₀ and a reduction in F_M were observed mainly at 50 °C and 55 °C, due to changes in the stages of the OJIP curve. These changes impacted the “energy connectivity” and consequently the electron transport along the electron transfer chain (ETC), increasing energy dissipation, as confirmed by the JIP_Test variables. Despite the high temperature impacts, previous water deficit induced heat tolerance in clone ‘A1’, while it increased sensitivity in clone ‘3V’. This study suggests that selecting drought-resistant varieties should consider their subsequent response to short high-temperature stress to avoid cross-sensitivity caused by selecting for a single environmental factor. Full article

Considering the synergistic optimization design of battery thermal safety and system economy in extreme environments, a hybrid lithium-ion battery thermal management system (BTMS) employing composite phase change material (CPCM) with liquid cooling is proposed by comparing four BTMSs of pure air cooling, pure CPCM, pure liquid cooling, and the hybrid cooling using CPCM and liquid cooling. The proposed hybrid cooling system demonstrates the capability to maintain the maximum battery temperature at 45.27 °C under extreme operating conditions, including elevated ambient temperatures of 40 °C combined with 5C discharge rate. Notably, this thermal regulation performance is achieved without requiring additional power input, highlighting the energy-efficient design of the system. Further, to address the critical challenge of thermal runaway prevention under summer extreme temperature up to 50 °C, an artificial neural network (ANN) model is established for the hybrid cooling, integrated with the non-dominated sorting genetic algorithm II (NSGA-II) algorithm, leading to the maximum temperature controlled at 48.68 °C and minimum system power consumption of 158 W, achieving a 12.1% reduction in thermal fluctuation amplitude and a 5.9% reduction in power consumption compared to initial design and optimal solutions, respectively. The proposed BTMS introduces the NSGA-II-ANN model for multi-objective collaborative optimization to solve the contradiction between thermal safety and energy consumption under extreme working conditions, enhancing the safety measures of power batteries and economic viability for electric vehicles. Full article

Dill is a valuable herb recognized for its rich nutritional composition and bioactive properties. Drying is an efficient preservation technique for maintaining its quality characteristics and ensuring longer storage stability. Incorporating ultrasonic pretreatment before the drying process can significantly reduce energy consumption (SEC) and greenhouse gas emissions. To the best of our knowledge, this is the first study to comprehensively evaluate ultrasound-assisted hybrid microwave–convective drying of dill (Anethum graveolens L.) leaves, focusing on the combined effects on drying kinetics, energetic and exergetic performance, providing an indirect emission estimate and multiple quality attributes. This study aimed to evaluate the drying kinetics, energy and exergy performance parameters, greenhouse gas emissions, quality properties (water activity, rehydration ratio and color) and antioxidant capacity of dill leaves dried by the microwave–hot-air (MW-HA) technique combined with ultrasonic (US) pretreatment. The experiments were conducted at MW power levels of 20%, 40%, and 60% (corresponding to a total output of 900 W), air temperatures of 40 and 60 °C, and US pretreatment durations of 0, 10, and 30 min. The results illustrated that rising MW power, air temperature and US duration significantly reduced the drying time, SEC and greenhouse gas emissions. At higher process conditions, specifically, 40% MW power, 60 °C drying temperature, and 30 min US pretreatment, the maximum energy efficiency (10.17%) and exergy efficiency (11.35%) were obtained. In terms of quality attributes, the best results were achieved at 40% MW power, 60 °C air temperature, and 10 min ultrasonic pretreatment, with reduced water activity (0.258), minimal color variation (ΔE = 11.44), improved rehydration ratio (3.88), and high retention of antioxidant activity. These findings demonstrate the potential of ultrasound pretreatment to enhance drying performance by reducing energy use and emissions while improving quality and antioxidant retention in dill, offering new guidelines for sustainable processing of this herb. Future studies should optimize microwave–hot-air-drying conditions to balance energy efficiency, exergy, and product quality. Full article