Search Results (46)

The problem of the post-harvest loss of perishable products has been a loss facing food security, especially in areas that lack adequate cold chain facilities. This issue is directly connected with sustainability objectives because post-harvest losses are the major source of food wastage, unneeded energy use, and related greenhouse gas emissions. Cold storage with phase-change material (PCM) is a promising alternative, as it aims at stabilizing temperatures and enhancing energy consumption, but current analyses of performance have been conducted through experimental testing and computational fluid dynamic (CFD) simulations, which are precise but computationally expensive. To handle this drawback, the current work constructs a machine learning predictive model to predict the dynamics of charging and discharging temperature of PCM cold storage systems. Four regression models, namely Random Forest, Extreme Gradient Boosting (XGBoost), Support Vector Regression (SVR), and K-Nearest Neighbors (KNNs), were trained and tested on experimental datasets that were obtained for varying storage layouts. The various error and accuracy measures used to determine model performance comprised MSE, MAE, R², MAPE, and percentage accuracy. The findings suggest that Random Forest provides the best accuracy during both the charging and the discharging process, with the highest R² values of over 0.98 and with minimal mean absolute errors. The KNN model was competitive in the discharge process, especially in cases of consistent thermal recovery patterns, and XGBoost was consistent in layout accuracy. However, SVR had relatively lower robustness, particularly when using nonlinear charged dynamics. Among the evaluated models, the Random Forest algorithm demonstrated the highest predictive accuracy, achieving coefficients of determination (R²) exceeding 0.98 for both charging and discharging processes, with mean absolute errors below 0.6 °C during charging and 0.3 °C during discharging. This paper has proven that machine learning is an efficient surrogate to CFD and experimental-only methods and can be used to predict the thermal behavior of PCM quickly and precisely. The proposed framework will allow for developing cold storage systems based on energy efficiency, low costs, and sustainability, especially in the context of decentralized and resource-limited agricultural supply chains, with the help of quick and data-focused forecasting of PCM thermal behavior. Full article

This paper presents a side-by-side study of CFD predictions and experimental measurements for a novel counter-flow heat exchanger installed in the sidewall of a dishwasher (HEBS). The work aims to improve appliance efficiency by transferring heat from discharged hot wastewater to the incoming cold supply. Motivated by sustainability goals and tightening EU energy rules, the research targets the high losses typical of conventional machines. This approach combines detailed ANSYS Fluent 2022R2 simulations with controlled laboratory tests on a bespoke test rig. The measured data show a repeatable rise in the cold-water temperature of roughly 8 K, corresponding to an approximate 15% gain in thermal performance for the heat-recovery stage. While the simulations and experiments efficiently agree based on trends and qualitative behavior, there are noticeable quantitative differences in the total energy transfer, indicating the models need further refinement. The validation carried out here forms a solid basis for design optimization and for reducing energy consumption in household dishwashers. This work overcomes the limitations of previous studies which typically rely on external storage tanks or static heat recovery analysis. The primary novelty of this paper lies in the empirical validation of a high-efficiency heat exchanger integrated into the extremely constrained sidewall volume of the appliance, tested under transient, on-the-fly flow conditions, providing a verified methodology for constrained industrial applications. Full article

The global food industry is undergoing a critical shift toward sustainability, driven by high postharvest losses—reaching up to 40% for fruits and vegetables—and the need to reduce environmental impact. Sustainable postharvest innovations focus on improving quality, extending shelf life, and minimizing waste through eco-efficient technologies. Advances in non-thermal and minimal processing, including ultrasound, pulsed electric fields, and edible coatings, support nutrient preservation and food safety while reducing energy consumption. Although integrated postharvest technologies can reduce deterioration and microbial spoilage by 70–92%, significant challenges remain, including global losses of 20–40% and the high implementation costs of certain nanostructured materials. Simultaneously, eco-friendly packaging solutions based on biodegradable biopolymers and bio-composites are replacing petroleum-based plastics and enabling intelligent systems capable of monitoring freshness and detecting spoilage. Energy-efficient storage, smart sensors, and optimized cold-chain logistics further contribute to product integrity across distribution networks. In parallel, the circular bioeconomy promotes the valorization of agro-food by-products through the recovery of bioactive compounds with antioxidant and anti-inflammatory benefits. Together, these integrated strategies represent a promising pathway toward reducing postharvest losses, supporting food security, and building a resilient, environmentally responsible fresh produce system. Full article

Current CO₂-based energy storage systems still face several unsolved technical challenges, including strong thermal destruction between the multi-stage compression and expansion processes, significant exergy destruction in heat exchange units, limited utilization of low-grade heat, and the lack of an integrated comprehensive performance framework capable of simultaneously evaluating thermodynamic, economic, and environmental performance. Although previous studies have explored various compressed CO₂ energy storage (CCES) configurations and CCES–Organic Rankine Cycle (ORC) couplings, most works treat the two subsystems separately, neglect interactions between the heat exchange loops, or overlook the combined effects of exergy losses, cost trade-offs, and CO₂-emission reduction. These gaps hinder the identification of optimal operating conditions and limit the system-level understanding needed for practical application. To address these challenges, this study proposes an innovative system that integrates a multi-stage CCES system with ORC. The system introduces ethylene glycol as a dual thermal carrier, coupling waste-heat recovery in the CCES with low-temperature energy utilization in the ORC, while liquefied natural gas (LNG) provides cold energy to improve cycle efficiency. A comprehensive 4E (energy, exergy, economic, and environmental) assessment framework is developed, incorporating thermodynamic modeling, exergy destruction analysis, CEPCI-based cost estimation, and environmental metrics including primary energy saved (PES) and CO₂ emission reduction. Sensitivity analyses on the high-pressure tank (HPT) pressure, heat exchanger pinch temperature difference, and pre-expansion pressure of propane (P₃₀) reveal strong nonlinear effects on system performance. A multi-objective optimization combining NSGA-II and TOPSIS identifies the optimal operating condition, achieving 69.6% system exergy efficiency, a 2.07-year payback period, and 1087.3 kWh of primary energy savings. The ORC subsystem attains 49.02% thermal and 62.27% exergy efficiency, demonstrating synergistic effect between the CCES and ORC. The results highlight the proposed CCES–ORC system as a technically and economically feasible approach for high-efficiency, low-carbon energy storage and conversion. Full article

Heart transplantation is severely limited by the shortage of suitable donor grafts, partly due to myocardial vulnerability to ischemia–reperfusion injury and the lack of standardized preservation strategies. Current solutions only partially maintain myocardial viability, compromising post-transplant function. To address this issue, we made further improvements to our preservation solution, LYPS (Lyon Preservation Solution), based on mitochondrial metabolic activation and the limitation of membrane depolarization. We first evaluated commonly used extracellular solutions (Celsior and St. Thomas (ST)) on cardiac cell lines (H9C2) exposed to 20 h of cold (4 °C) simulated ischemia followed by 2 h of simulated reperfusion. In parallel, the same three solutions were compared in isolated pig hearts subjected to 20 h of cold static storage followed by reperfusion, with a group directly reperfused with blood at 37 °C serving as the control. Heart function was assessed using a non-working heart preparation, while mitochondrial functions and electrophysiological analysis were evaluated via biopsies and isolated cardiomyocytes. LYPS provided superior protection against cell death and mitochondrial membrane potential loss in vitro, outperformed ST in preserving mitochondrial function, and limited troponin I release by the heart. During reperfusion, LYPS-treated hearts showed improved functional recovery and contractility and better rhythmicity with almost no defibrillation requirements. These effects may involve the modulation of the repolarizing IK₁ current. Overall, LYPS effectively preserves myocardial viability and function, representing a promising strategy to enhance graft quality during long-term cold preservation, even through using cold static storage. Full article

The sustainable exploitation of geothermal energy is often challenged by issues such as groundwater level decline and thermal attenuation. This study focuses on the sandstone thermal reservoir in Linqing City, Shandong Province. A three-dimensional thermo-hydro-mechanical (THM) multi-field coupling numerical model is developed to simulate the evolution of geothermal water levels and temperature fields under varying reinjection rates. The model was validated against observed water level and temperature data, showing maximum deviations of 1.62 m and 0.6 °C. Simulation results indicate that increasing the reinjection rate mitigates water-level decline but accelerates thermal breakthrough, expanding the low-temperature zone. At a 100% reinjection rate, the minimum temperature at the bottom of the thermal reservoir decreases to 63.6 °C, and the low-temperature area extends to 11.61 km². Moderate reinjection rates help to slow thermal energy loss while maintaining reservoir pressure and stabilizing water levels. This study reveals the dual effects of reinjection rate on the balance of geothermal system and puts forward suggestions on optimizing well spacing according to the simulated advance rate of cold waterfront, so as to ensure sustainable thermal recovery. It provides theoretical basis and numerical simulation support for reinjection strategy optimization and well spacing design of similar geothermal fields in Linqing and North China Plain. Full article

Cold stress reduces horticultural crop yield and postharvest quality by disrupting membrane fluidity, redox equilibrium, and the cell wall structure. This results in chilling injury, tissue softening, and loss of color. Long noncoding RNAs (lncRNAs) have emerged as key integrators of plant cold signaling pathways. LncRNAs mediate the interaction between calcium signaling systems and transcriptional cascades while coordinating hormone signaling networks, including those involving abscisic acid, jasmonic acid, ethylene, salicylic acid, and brassinosteroids. LncRNAs influence gene regulation through chromatin-based guidance, sequestration of repressive complexes, natural antisense transcriptional interference, microRNA-centered competing endogenous RNA networks, and control of RNA splicing, stability, localization, and translation. Studies in horticultural species revealed that cold-responsive lncRNAs regulate processes essential for fruit firmness, antioxidant levels, and shelf-life, including lipid modification, reactive oxygen species balance, and cell wall or cuticle remodeling. This review aims to summarize tissue- and developmental stage-specific expression patterns and highlight experimental approaches to validate RNA function, including gene editing, transcript recovery, advanced sequencing, and analysis of protein-RNA interactions. Integrating these results will facilitate the development of precise molecular markers and nodes of regulatory networks that increase cold tolerance, and improve the quality of horticultural crops. Full article

Sustainable manure recycling in cold climates faces low efficiency and nutrient loss. This study evaluated housefly larva-pretreated manure (HL) for winter swine manure composting in East China, comparing it to sawdust-conditioned (CK2) and untreated manure (CK1). Larval pretreatment converted 12.71% of manure weight into biomass, assimilating 10.69% C, 30.55% N, 8.54% P, and 11.53% K. Harvested larvae contained 53.35% crude protein, with amino acids matching/exceeding fishmeal and soybean meal, while heavy metals were below safety limits. Theoretical annual larval protein yield per unit area (29,530 kg·mu⁻¹·year⁻¹) was 206.5 times higher than soybean crops. During composting, the HL treatment promoted early protease and catalase activation. This enzymatic synergy accelerated organic matter degradation and maturation, achieving a germination index of 147.67% by day 51. Coordinated nitrate and nitrite reductase activity in HL facilitated efficient denitrification, minimizing NO₂⁻ accumulation and N₂O emissions. Consequently, HL composting achieved faster stabilization, enhanced nutrient retention, and greater protein recovery compared to controls. These findings demonstrate that housefly larval pretreatment offers a climate-resilient and scalable strategy for winter manure management and protein valorization, with strong potential for applications in cold and resource-limited agricultural systems worldwide. Full article

The parturition season of grazing Tibetan ewes spans from October to March, a period that exacerbates the adverse impacts of nutrient-deficient herbage on milk yield, body condition, and postpartum recovery. To alleviate the weight loss of ewes during the cold seasons, we provided concentrate supplements at four levels (dry matter (DM) basis), 260 g (C1), 440 g (C2), 520 g (C3), and 610 g (C4), alongside a basal diet of grazed pasture. A total of 96 multiparous Tibetan ewes (third parity, body weight: 45.17 ± 3.69 kg (body weight (BW) were enrolled within 12–18 h postpartum and randomly allocated to four dietary groups (n = 24 ewes per group). We measured growth performance, ruminal histomorphology, fermentation parameters, and digestive enzymes. A multi-omics technique (16S rRNA gene sequencing and RNA-seq) was employed to investigate the mechanisms underlying alterations in ruminal function. The results showed that increasing the concentrate level decreased body weight loss and increased average dry matter intake (p < 0.05). Rumen morphology was significantly altered: papilla width and muscle layer thickness were greatest in the C4 group, whereas submucosal thickness was highest in the C1 group (p < 0.05). Cellulase activity was lowest in the C1 group (p < 0.05). Papilla width of lactating Tibetan ewes in the C4 group was higher (p < 0.05) than that in the C1 and C3 groups. Concentrate supplementation altered ruminal microbiota composition and diversity. Each group exhibited a distinct microbial signature: the C1 group was characterized by Lachnospiraceae_XPB1014_group, Candidatus_Omnitrophus, Paenibacillus, and unclassified_Oligoflexaceae; the C2 group was enriched in Papillibacter, Anaerovibrio, V9D2013_group, and unclassified_Peptococcaceae; the C3 group was characterized by unclassified_Bacteroidales_RF16_group; and the C4 group was characterized by Ruminococcus, Pseudobutyrivibrio, and Mitsuokella (p < 0.05). Transcriptomic analysis identified differentially expressed genes (TRPA1, EPHB1, GATA3, C4, ABCG2, THBS4, and TNFRSF11B) that are predominantly involved in immune regulation, signal transduction, and nutrient digestion. The results of Spearman correlation analysis showed that Anaerovibrio was negatively correlated with propionate (r = −0.565, p < 0.05). However, it was positively correlated with the ratio of acetate and propionate (r = 0.579, p < 0.05). Moreover, Lachnospiraceae_XPB1014_group was negatively correlated with cellulase (r = −0.699, p < 0.05) and α-amylase (r = −0.514, p < 0.05). These findings suggest that the increasing concentrate supplementation alleviates body weight loss in lactating Tibetan sheep by orchestrating improvements in rumen histomorphology, digestive function, altering bacteria composition, and ruminal immune and modulating host epithelial gene expression. Full article

The effect of ore pre-heating on the operation of a 300 kVA Submerged Arc Furnace (SAF) for high carbon ferromanganese (HCFeMn) alloy was investigated. The two types of Mn ores from the Kalahari Manganese Field (KMF) were used in the investigation (Ore #1 and Ore #2). Quartz and coke sourced from South Africa were used as a fluxing agent and a reductant, respectively. The Mn ores, reductant and fluxing agent were delivered to Mintek with a size range of +6–20 mm and were sent to our in-house laboratories to determine the chemical and physical properties. The samples were taken for Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), combustion method (LECO), proximate analysis and quantitative X-ray diffraction (QXRD). A newly designed and constructed pilot facility at Mintek was used in the investigation. The facility included a 1 t/h rotary kiln coupled to an electric arc furnace supplied with an alternating current (AC) with a 300 kVA tap-changer transformer. The main aim of the investigation was to demonstrate the effect of ore pre-heating to 600 °C on the furnace energy consumption and CO/CO₂ emissions. The experimental approach adopted involved feeding Mn ore to establish baseline operating conditions, followed by feeding of Mn ore pre-heated with a rotary kiln to compare operational parameters. The pilot campaign experienced several operational challenges but there were periods of stable operation that enabled data collection for furnace energy consumption and CO/CO₂ emissions. The effect of pre-heating the ore to 600 °C on the SAF energy consumption and CO/CO₂ emissions was demonstrated successfully and revealed that energy savings and reduction in furnace CO₂ emissions is achievable. Pre-heating Mn ore to 600 °C lowered the furnace energy consumption by an average of 22.5% and CO₂ emissions by an average of 37%. The campaign also achieved an overall manganese recovery of 86%. Operating the furnace with hot feed increased the heat losses through the roof by 300% compared to heat losses observed during cold feed. There were also no significant changes in the furnace electrical parameters observed between the two feed modes. Full article

Waste heat utilization in fuel cell vehicles represents a critical technology for enhancing overall energy utilization efficiency and environmental adaptability, which reduces auxiliary heating consumption, extends driving range, and minimizes thermal management parasitic losses, holding significance for promoting application of fuel cell commercial vehicles. This study investigates a 49-ton fuel cell heavy-duty truck equipped with waste heat recovery capability, conducting vehicle energy flow experiments under multiple ambient temperatures (including 7 °C, $-7$ °C and $-25$ °C extreme cold conditions), varying load conditions, and waste heat recovery mode switching, with focused analysis on the energy consumption and temperature response of the waste heat recover critical components, to evaluate the energy utilization of fuel cell waste heat. Experimental results demonstrate the substantial impact of waste heat recovery function on the proportion of the warm air positive temperature coefficient (PTC) energy consumption on total energy consumption, showing that deactivating waste heat recovery increased the PTC energy consumption obviously. Besides, activating the waste heat recovery function contributes to elevated the stack radiator outlet temperature under low-temperature operating conditions. Full article

Maintaining or improving habitat quality is essential for conserving biodiversity and ensuring the long-term survival of species. Nevertheless, increasing global warming and intensifying human activities have led to varying degrees of habitat degradation and biodiversity loss, especially in semi-arid regions. Focusing on China’s West Songnen Plain—the nation’s largest saline-alkali region confronting acute environmental challenges—this study introduced the soil salinization level and mean NDVI of farmland during the growing season as dynamic threat factors and systematically explored the spatiotemporal dynamic characteristics of habitat quality in the semiarid area of the West Songnen Plain from 1990 to 2020. The results showed the following: (1) Habitat quality exhibited a continuous decline during the study period, following a “degradation–recovery” trajectory with deterioration peaking in 2010; the low- and poor-quality habitats predominantly distributed in the central areas characterized by severe salinization, interspersed with patches of good-quality habitat. (2) The degradation of habitat quality was mainly concentrated in natural land cover types, whereas improvements were observed locally in farmland and bare land. However, slight opposite trends were detected between the mean habitat quality values and the habitat change areas in forests, waters, and bare land. As the elevation continuously increased, the habitat quality grade shifted towards better conditions. (3) A spatial autocorrelation analysis revealed a significant clustering of habitat quality, but the extent of hot spots and cold spots gradually shrank as grassland degradation and saline land management progressed. By incorporating dynamic threat factors and integrating multi-source data, this study improved the habitat quality assessment framework for semi-arid regions and provided scientific support for spatially stratified conservation strategies. Full article

Background: Injuries to the digital distal phalanx often result in functional impairments such as loss of grip and sensation, along with aesthetic challenges. Various reconstructive techniques, including the use of adipofascial flaps, have been explored to address these issues. The homodigital dorsal adipofascial reverse flap (HDARF) has demonstrated promising results in restoring both functionality and aesthetics. However, a comparative evaluation between adipofascial flaps and other commonly used techniques, such as V-Y advancement flaps and cross-finger flaps, remains limited. Objective: This retrospective study evaluates the long-term functional and aesthetic outcomes of adipofascial flap reconstructions for pulp defects, focusing on sensory recovery and patient satisfaction. Methods: Between 2010 and 2022, 20 patients (14 men, 6 women) with digital pulp defects underwent reconstruction using adipofascial flaps in a single-stage procedure. Injuries included avulsion and crush injuries, distributed across various digits. Sensory recovery was assessed using the Semmes–Weinstein monofilament test and two-point discrimination. Joint mobility, cold intolerance, and aesthetic satisfaction were also evaluated. Results: All flaps were successfully reconstructed within 24 h of trauma. Sensory recovery was excellent, with Semmes–Weinstein scores ranging from 1.65 to 2.83, comparable to the uninjured hand. Two-point discrimination averaged 1–5 mm in most cases. Cold intolerance persisted in four patients, and mild nail dystrophy was noted in three cases, with one case of nail absence. Aesthetic satisfaction was high in 19 patients. Conclusions: The adipofascial flap effectively restores function and aesthetics in pulp defects, offering superior sensory recovery, high patient satisfaction, and minimal complications. Its regenerative potential and adaptability make it a valuable option for fingertip reconstruction, supporting its continued use in clinical practice. Full article

Oral mucositis associated with candidiasis can causes systemic candidemia, posing a risk to cancer patients administered antineoplastic therapy. Cold atmospheric pressure plasma jets (CAPPJs) have antifungal and anti-inflammatory properties. This study evaluated the effects CAPPJs in preventing systemic fungal dissemination in a murine model of oral mucositis associated with candidiasis. Forty Wistar rats were divided into groups: CAPPJs (treated) and non-treated controls (for comparison), with subgroups subject to 24 and 72 h of treatment (n = 10 each). Four cycles of chemotherapy (cisplatin and 5-fluorouracil (5-FU)) were administered, followed by oral inoculation of Candida albicans for 3 days. Mucosal damage was induced on the lateral side of tongue with 50% acetic acid. CAPPJ treatment was performed on the lesion for 5 min (2 days). Body weight was assessed daily. Fungal dissemination was conducted using organ macerates and plated on Sabouraud Agar with chloramphenicol. Blood samples were obtained for blood count tests. Chemotherapy affected the general health of the animals, as evidenced by body weight loss. Treatment with CAPPJs showed an inhibitory effect on C. albicans, with a significant reduction in fungal recovery from the tongue after 24 h (p < 0.05). Interestingly, systemic fungal dissemination was significantly reduced after 24 and 72 h of treatment when compared to control (p < 0.05). Taken together, these results suggest that CAPPJs have potential for clinical application in patients with oral mucositis at risk of candidemia. Full article

Over 50% of an engine’s energy dissipates via the exhaust and cooling systems, leading to considerable energy loss. Effectively harnessing the waste heat generated by the engine is a critical avenue for enhancing energy efficiency. Traditional exhaust heat recovery systems are limited to real-time recovery of exhaust heat primarily for engine warm-up and fail to fully optimize exhaust heat utilization. This paper introduces a novel exhaust heat recovery system leveraging thermal battery technology, which utilizes phase change materials for both heat storage and reutilization. This innovation significantly minimizes the engine’s cold start duration and provides necessary heating for the cabin during start-up. Dynamic models and thermal management system models were constructed. Parameter optimization and calculations for essential components were conducted, and the fidelity of the simulation model was confirmed through experiments conducted under idle warm-up conditions. Four distinct operational modes for engine warm-up are proposed, and strategies for transitioning between these heating modes are established. A simulation analysis was performed across four varying operational scenarios: WLTC, NEDC, 40 km/h, and 80 km/h. The results indicated that the thermal battery-based exhaust heat recovery system notably reduces warm-up time and fuel consumption. In comparison to the cold start mode, the constant speed condition at 40 km/h showcased the most significant reduction in warm-up time, achieving an impressive 22.52% saving; the highest cumulative fuel consumption reduction was observed at a constant speed of 80 km/h, totaling 24.7%. This study offers theoretical foundations for further exploration of thermal management systems in new energy vehicles that incorporate heat storage and reutilization strategies utilizing thermal batteries. Full article