Search Results (5,327)

The thermal, thermomechanical, and viscoelastic properties of continuous unidirectional (UD) glass fiber/high-density polyethylene (GF/HDPE) and ultra-high-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE) tapes are characterized in this paper in order to support their use in extreme environments. Unlike prior studies that focus on short-fiber composites or limited thermal conditions, this work examines continuous fiber architectures under five operational environments derived from Army Regulation 70-38, reflecting realistic defense-relevant extremes. Differential scanning calorimetry (DSC) was used to identify melting transitions for GF/HDPE and UHMWPE/HDPE, which guided the selection of test conditions for thermomechanical analysis (TMA) and dynamic mechanical analysis (DMA). TMA revealed anisotropic thermal expansion consistent with fiber orientation, while DMA, via strain sweep, temperature ramp, frequency sweep, and stress relaxation, quantified their temperature- and time-dependent viscoelastic behavior. The frequency-dependent storage modulus highlighted multiple resonant modes, and stress relaxation data were fitted with high accuracy (R² > 0.99) to viscoelastic models, yielding model parameters that can be used for predictive simulations of time-dependent material behavior. A comparative analysis between the two material systems showed that UHMWPE/HDPE offers enhanced unidirectional stiffness and better low-temperature performance. At the same time, GF/HDPE exhibits lower thermal expansion, better transverse stiffness, and greater stability at elevated temperatures. These differences highlight the impact of fiber type on thermal and mechanical responses, informing material selection for applications that require directional load-bearing or dimensional control under thermal cycling. By integrating thermal and viscoelastic characterization across realistic operational profiles, this study provides a foundational dataset for the application of continuous fiber thermoplastic tapes in structural components exposed to harsh thermal and mechanical conditions. Full article

Spacecraft and satellites are equipped with cryogenic storage systems to maintain instruments and engines at optimal operating temperatures. However, in cryogenic storage tanks, the steep temperature gradient along the pipeline (arising from sections inside and outside the tank) may induce instability in stored gases such as helium or hydrogen, leading to large-amplitude, self-excited thermoacoustic oscillations, known as Taconis oscillations. Taconis oscillations not only cause structural damage to pipelines, jeopardizing the safety of the cryogenic storage system, but also produce significant heat leakage and boil-off losses of cryogens. This study employs computational fluid dynamics (CFD) to simulate Taconis oscillations within a U-shaped cryogenic helium pipeline. The flow dynamics and acoustic field characteristics of the cryogenic helium pipeline are first analyzed. Fast Fourier transform and wavelet transform are employed to characterize the Taconis oscillations. A subsequent parametric study investigates the influence of the location and magnitude of temperature gradients on the dynamic behavior of Taconis oscillations. Simulation results reveal that the onset temperature gradient is at a minimum when the temperature gradient is applied at one-quarter of the cryogenic pipeline. To prevent the occurrence of Taconis oscillations, the transition between the warm and cold sections should be away from one-quarter of the cryogenic helium pipe. Moreover, increasing the temperature gradient leads to the emergence of multiple oscillation modes and an upward shift in their natural frequencies. This research gives deeper insights into the dynamics of thermally induced thermoacoustic oscillations in cryogenic pipelines, providing guidelines for improving the efficiency and safety of cryogenic storage systems in aerospace engineering. Full article

Methane, transported as Liquefied Natural Gas (LNG) at −163 °C, is becoming the leading fuel in the decarbonization of the maritime sector within the low-carbon fuels. More than 30 years of knowledge has allowed the development of an extensive offshore supply network that includes regasification plants to store and supply it to the grid, both onshore and offshore. This article first reviews the current state of the sector. Then, the operation of a typical onshore regasification plant and the heat transfer through the storage tanks that causes the generation of boil-off gas (BOG) are analyzed by means of two different methodologies. Finally, and based on the results obtained, the different improvements that can be implemented in this type of installation to improve its energy efficiency and insulation are established, such as, for example, an improvement of more than 4 W/m² by reinforcing the thickness of the materials of the tank dome. Full article

Energy shortage and environmental pollution have accelerated the adoption of lithium-ion batteries (LIBs) as efficient energy storage solutions. However, their performance and safety challenges under extreme temperatures highlight the urgent need for effective temperature control during charging and discharging, making a comprehensive understanding of electrochemical and thermal behaviors crucial. This paper develops a 3D electrochemical–thermal coupled model for 150 Ah lithium iron phosphate (LFP) batteries to investigate thermal behavior at varying charge–discharge rates. An integrated learning regression prediction system, incorporating a structured vector autoregression (SVAR) model, is subsequently proposed to analyze the interactions among multiple electrochemical and thermal variables. The temperature difference exceeds 5 °C at higher charging rates (1.3C, 1.5C), driven primarily by accelerated heat generation—especially reversible heat. Complex interactions exist between electrochemical and thermal parameters. When charging at 0.5C, voltage, current density, battery capacity, and the maximum temperature difference (MTD) are all significantly and positively correlated (p < 0.001). Under 1C discharge conditions, voltage exhibits a strong positive correlation with most thermal characteristic variables, and correlation coefficients across different operating conditions range from −0.9731 to 0.973. Finally, the proposed ensemble learning system exhibits excellent prediction accuracy, strong generalization, and robust trend analysis, with practical guiding value. Full article

Date palm (Phoenix dactylifera L.) is a vital crop cultivated primarily in developing regions, playing a strategic role in global food security through its significant contribution to nutrition, economy, and livelihoods. Global and regional production trends revealed increasing demand and expanded cultivation areas, underpinning the fruit’s importance in national food security policies and economic frameworks. The date fruit’s rich nutritional profile, encompassing carbohydrates, dietary fiber, minerals, and bioactive compounds, supports its status as a functional food with health benefits. Postharvest technologies and quality preservation strategies, including temperature-controlled storage, advanced drying, edible coatings, and emerging AI-driven monitoring systems, are critical to reducing losses and maintaining quality across diverse cultivars and maturity stages. Processing techniques such as drying, irradiation, and cold plasma distinctly influence sugar composition, texture, polyphenol retention, and sensory acceptance, with cultivar- and stage-specific responses guiding optimization efforts. The cold chain and innovative packaging solutions, including vacuum and modified atmosphere packaging, along with biopolymer-based edible coatings, enhance storage efficiency and microbial safety, though economic and practical constraints remain, especially for smallholders. Microbial contamination, a major challenge in date fruit storage and export, is addressed through integrated preservation approaches combining thermal, non-thermal, and biopreservative treatment. However, gaps in microbial safety data, mycotoxin evaluation, and regulatory harmonization hinder broader application. Date fruit derivatives such as flesh, syrup, seeds, press cake, pomace, and vinegar offer versatile functional roles across food systems. They improve nutritional value, sensory qualities, and shelf life in bakery, dairy, meat, and beverage products while supporting sustainable waste valorization. Emerging secondary derivatives like powders and extracts further expand the potential for clean-label, health-promoting applications. This comprehensive review underscores the need for multidisciplinary research and development to advance sustainable production, postharvest management, and value-added utilization of date palm fruits, fostering enhanced food security, economic benefits, and consumer health worldwide. Full article

The use of thermal insulation material in building envelopes is closely related to economic benefits, energy-savings, and carbon reduction of buildings. The construction forms of different components in building envelopes have an important influence on the optimization design of thermal insulation in building envelopes. In this study, an integrated optimization approach is proposed to search for the best solution of thermal insulation in external walls and the optimal combination scheme of different construction forms of envelope components in granaries. The integrated optimization approach consists of an orthogonal experimental design (OEDM) method-based determination module of an optimal combination scheme of different construction forms of components, an assessment model-based quantitative analysis module, and an integrated assessment indicator-based selection module of the best solution of external wall insulation. Firstly, the OEDM method is used to determine the optimal combination scheme of different construction forms of the foundation wall of an external wall, thermal insulation material, external window, roof, and floors in buildings. Secondly, integrated economic, energy, and carbon analysis models are developed to analyze comprehensive performance of external wall insulation. Finally, an integrated assessment indicator consisting of an energy balanced index, a carbon balanced index, and weight coefficients is presented to determine the best solution of external wall insulation. The applications of this optimization approach in different ecological grain storage zones in China demonstrated that the outdoor air temperature characteristics could affect the comprehensive performance of external wall insulation in granaries, significantly. The best solution of external wall insulation in granaries in Turpan city, Daqing city, Kaifeng city, Changsha city, Anshun city, and Danzhou city was expanded polystyrene insulation (EPS) with a layer thickness of 0.078 m, 0.048 m, 0.083 m, 0.089 m, 0.062 m, and 0.131 m, respectively. The greatest difference in the lowest entire construction cost and the lowest carbon emission of external wall insulation among different typical climate regions in China was 12.987 USD/m² and 6.3 kgCO2e/m², respectively. Full article

As consumer awareness grows and regulations regarding the quality and safety of perishable goods become stricter, careful management of environmental conditions throughout the supply chain is becoming essential. Among these factors, storage temperature plays a crucial role in preserving the physicochemical characteristics of products. Therefore, an effective approach to ensure quality and safety up to the final customer is to continuously monitor the temperature within warehouses, using specific location-mapping techniques and stocking optimization methods. This study proposes a dynamic optimization model for the storage location assignment problem, integrating both temperature and humidity constraints into the placement of stock-keeping units. The model operates under a multi-period, multi-product framework and leverages real-time sensor data to account for spatial temperature stratification and environmental variability within the warehouse, contributing to the reduction in the energy consumption. Two alternative optimization strategies are explored: one focused on minimizing thermal and humidity stress, and another targeting the reduction in average storage cycle time. A detailed what-if analysis is conducted across three scenarios, varying warehouse fill rates and incoming load volumes, in order to prove the effectiveness of the proposed model in a real-data context. The results show that the approach minimizing environmental stress consistently outperforms traditional methods in quality-related metrics, maintaining superior objective function values. Full article

Veterinary vaccines are essential tools for controlling infectious and zoonotic diseases, safeguarding animal welfare, and ensuring global food security. However, conventional vaccines are hindered by cold-chain dependence, thermal instability, and logistical challenges, particularly in low- and middle-income countries (LMICs). This review explores next-generation veterinary vaccines, emphasizing innovations in thermostability and delivery platforms to overcome these barriers. Recent advances in vaccine drying technologies, such as lyophilization and spray drying, have improved antigen stability and storage resilience, facilitating effective immunization in remote settings. Additionally, novel delivery systems, including nanoparticle-based formulations, microneedles, and mucosal routes (intranasal, aerosol, and oral), enhance vaccine efficacy, targeting immune responses at mucosal surfaces while minimizing invasiveness and cost. These approaches reduce reliance on cold-chain logistics, improve vaccine uptake, and enable large-scale deployment in field conditions. The integration of thermostable formulations with innovative delivery technologies offers scalable solutions to immunize livestock and aquatic species against major pathogens. Moreover, these strategies contribute significantly to One Health objectives by mitigating zoonotic spillovers, reducing antibiotic reliance, and supporting sustainable development through improved animal productivity. The emerging role of artificial intelligence (AI) in vaccine design—facilitating epitope prediction, formulation optimization, and rapid diagnostics—further accelerates vaccine innovation, particularly in resource-constrained environments. Collectively, the convergence of thermostability, advanced delivery systems, and AI-driven tools represents a transformative shift in veterinary vaccinology, with profound implications for public health, food systems, and global pandemic preparedness. Full article

This study investigates the effects of varying filler content on the thermal and mechanical performance of metakaolinite-based geopolymer composites designed for thermal energy storage applications. The composites were formulated using a geopolymer binder, combined with a thermally stable filler (ground chamotte) and a thermal energy storage filler (waste steel chips) in different proportions. Chamotte content within the binder matrix (binder + chamotte) ranged from 20 to 40 wt.%, while steel chip content varied from 0 to 40 wt.% of the total composite mass. The thermal properties of the composites were evaluated at room temperature and compared with conventional reference materials, including Ultraboard, chamotte brick, and magnetite brick. Mechanical performance, specifically flexural and compressive strength, was evaluated at room temperature and after exposure to elevated temperatures (800 and 1100 °C), followed by two cooling regimes, slow furnace cooling and rapid water quenching. Microstructural characterization via optical microscopy was used to examine filler dispersion and matrix–filler interactions. The results showed that the thermal effusivity of the optimized composites exceeded that of chamotte brick by more than 50%. The highest flexural (12.68 MPa) and compressive (86.18 MPa) strengths were achieved in the composite containing 20 wt.% steel chips, prior to thermal exposure. Microstructural observations revealed the diverse geometry of the steel chips and arrangement of the chamotte particles. These findings highlight the potential of incorporating metallic waste materials into geopolymer systems to develop multifunctional composites with improved thermal storage capacity and mechanical resilience. Full article

Solar thermal technology is an important component of low-carbon energy systems, but its application potential is constrained by two key factors: the inherent limits of energy flux density and the temporal mismatch between supply and demand. This study examined efficiency losses in building heating systems in Northwest China caused by the mismatch between supply and demand in intermittent solar thermal storage systems. Three typical building heating models (Day–Night Intermittent Mode, Day–Night + Monthly Intermittent Mode, and Composite Intermittent Mode (Day–Night + Weekly + Monthly)) were constructed through SketchUp, integrating the Transient System Simulation Tool (TRNSYS) with improved calculation methods in an innovative way. The study first examined regional energy consumption patterns and the temporal characteristics of building occupancy and then proposed a collaborative optimization framework for thermal collection and storage, focused on improving the dynamic matching algorithm of the thermal collection area ratio and the tank volume ratio and establishing a tank capacity calculation model that considers the time-varying characteristics of heat demand and fluctuations in thermal collection efficiency during the intermittent heating cycle. The results show that compared with continuous operation, the intermittent strategy reduces the annual cumulative heat load by 13–33%, among which the Day–Night Intermittent Mode shows the daily peak load reaches 1.8 times the normal value during restart, while the daily fluctuation amplitude of the Day–Night + Monthly Intermittent Mode decreases by 42%. The corresponding solar energy guarantee rate reaches 86–88%, and the heat storage loss is reduced by 19–27%. The time-varying coupling design method established in this study provides an optimization path that takes into account both system efficiency and economy for intermittent heating scenarios. The proposed dynamic capacity configuration criterion has universal guiding value for the design of solar district heating systems. Full article

Photodynamic inactivation (PDI) is an innovative non-thermal sterilization and preservation method that has recently emerged as a safe, effective, cost-effective and environmentally sustainable alternative for biomedical applications. Curcumin (Cur), a commonly used food additive, possesses photosensitizing properties. In this study, we investigated the effect of curcumin-mediated photodynamic treatment (Cur-PDT) on the preservation of fresh wolfberries. Our experimental data revealed that a Cur-PDT treatment using a cur concentration of 500 μmol/L for 30 min, with 20 W irradiation, achieved the best preservation effect on fresh wolfberries. This intervention significantly slowed the decline in post-harvest hardness and delayed the progression of decay. It also reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H₂O₂) and superoxide anion (•O₂⁻). Notably, at day 3, the enzymatic activities of catalase (CAT) and ascorbate peroxidase (APX) in Cur-PDT-treated wolfberries were 1.12 and 1.88 times higher, respectively, than those in the control group. These elevated enzyme activities promoted the biosynthesis and recycling of ascorbic acid (AsA) and glutathione (GSH), leading to their substantial accumulation under oxidative stress conditions. By modulating the antioxidant defense system, Cur-PDT has the potential to extend the shelf-life of post-harvest wolfberries and enhance their overall quality attributes, thereby maintaining physiological homeostasis during storage. Full article

Accurate parametric modeling of lithium-ion batteries is essential for battery management system (BMS) design in electric vehicles and broader energy storage applications, enabling reliable state estimation and effective thermal control under diverse operating conditions. This study presents a detailed characterization of lithium-ion cells to support advanced BMS in electric vehicles and stationary storage. A second-order equivalent circuit model is developed to capture instantaneous and dynamic voltage behavior, with parameters extracted through Hybrid Pulse Power Characterization over a broad range of temperatures (−10 °C to 45 °C) and state-of-charge levels. The method includes multi-duration pulse testing and separates ohmic and transient responses using two resistor–capacitor branches, with parameters tied to physical processes like charge transfer and diffusion. A weakly coupled electro-thermal model is presented to support real-time BMS applications, enabling accurate voltage, temperature, and heat generation prediction. This study also evaluates open-circuit voltage and direct current internal resistance across pulse durations, leading to power capability maps (“fish charts”) that capture discharge and regenerative performance across SOC and temperature. The analysis highlights performance asymmetries between charging and discharging and confirms model accuracy through curve fitting across test conditions. These contributions enhance model realism, thermal control, and power estimation for real-world lithium-ion battery applications. Full article

Due to their advantages, such as abundant raw material reserves, excellent thermal stability, and superior low-temperature performance, sodium-ion batteries (SIBs) exhibit significant potential for future applications in energy storage and electric vehicles. Therefore, in this study, a commercial pouch-type SIB with sodium iron sulfate cathode material was investigated. Firstly, a second-order RC equivalent circuit model was established through parameter identification using multi-rate hybrid pulse power characterization (M-HPPC) tests at various temperatures. Then, both the specific heat capacity and entropy coefficient of the sodium-ion battery were measured through experiments. Building upon this, an electro-thermal coupling model was developed by incorporating a lumped-parameter thermal model that accounts for the heat generation of the tabs. Finally, the prediction performance of this model was validated through discharge tests under different temperature conditions. The results demonstrate that the proposed electro-thermal coupling model can achieve the simultaneous prediction of both temperature and voltage, providing valuable references for the future development of thermal management systems for SIBs. Full article

To achieve energy conservation, emission reduction, and green low-carbon goals for gas storage facilities, it is crucial to efficiently recover and utilize waste heat during gas injection while maintaining natural gas cooling rates. However, existing sensible and latent heat storage technologies cannot sustain long-term thermal storage or seasonal utilization of waste heat. Thermal chemical energy storage, with its high energy density and low thermal loss during prolonged storage, offers an effective solution for efficient recovery and long-term storage of waste heat in gas storage facilities. This study proposes a novel heat recovery method by combining a moving bed with mixed hydrated salts (CaCl₂·6H₂O and MgSO₄·7H₂O). By constructing both small-scale and full-scale three-dimensional models in Fluent, which couple the desorption and endothermic processes of hydrated salts, the study analyzes the temperature and flow fields within the moving bed during heat exchange, thereby verifying the feasibility of this approach. Furthermore, the effects of key parameters, including the inlet temperatures of hydrated salt particles and natural gas, flow velocity, and mass flow ratio on critical performance indicators such as the outlet temperatures of natural gas and hydrated salts, the overall heat transfer coefficient, the waste heat recovery efficiency, and the mass fraction of hydrated salt desorption are systematically investigated. The results indicate that in the small-scale model (1164 × 312 × 49 mm) the outlet temperatures of natural gas and mixed hydrated salts are 79.8 °C and 49.3 °C, respectively, with a waste heat recovery efficiency of only 33.6%. This low recovery rate is primarily due to the insufficient residence time of high-velocity natural gas (10.5 m·s⁻¹) and hydrated salt particles (2 mm·s⁻¹) in the moving bed, which limits heat exchange efficiency. In contrast, the full-scale moving bed (3000 × 1500 × 90 mm) not only accounts for variations in natural gas inlet temperature during the three-stage compression process but also allows for optimized operational adjustments. These optimizations ensure a natural gas outlet temperature of 41.3 °C, a hydrated salt outlet temperature of 82.5 °C, a significantly improved waste heat recovery efficiency of 94.2%, and a hydrated salt desorption mass fraction of 69.2%. This configuration enhances the safety of the gas injection system while maximizing both natural gas waste heat recovery and the efficient utilization of mixed hydrated salts. These findings provide essential theoretical guidance and data support for the effective recovery and seasonal utilization of waste heat in gas storage reservoirs. Full article