Decreasing Temperature Research Articles

Aerodynamic and aeroacoustic sensitivities of contra-rotating open rotors to operational parameters

Abstract Open rotors can play a critical role towards transitioning to a more sustainable aviation by providing a fuel-efficient alternative. This paper considers the sensitivity of an open-rotor engine to variations of three operational parameters during take-off, focusing on both aerodynamics and aeroacoustics. Via a sensitivity analysis, insights to the complex interactions of aerodynamics and aeroacoustics can be gained. For both the aerodynamics and aeroacoustics of the engine, numerical methods have been implemented. Namely, the flowfield has been solved using unsteady Reynolds Averaged Navier Stokes and the acoustic footprint of the engine has been quantified through the Ffowcs Williams-Hawking equations. The analysis has concluded that the aerodynamic performance of the open rotor can decisively be impacted by small variations of the operational parameters. Specifically, blade loading increased by 9.8% for a 5% decrease in inlet total temperature with the uncertainty being amplified through the engine. In comparison, the aeroacoustic footprint of the engine had more moderate variations, with the overall sound pressure level increasing by up to 2.4dB for a microphone lying on the engine axis and aft of the inlet. The results signify that there is considerable sensitivity in the model and shall be systematically examined during the design or optimisation process.

Ferric oxide/ammonium nitrate nanocomposite: novel catalyzed eco-friendly oxidizer with advanced decomposition kinetics

ABSTRACT Ammonium nitrate (AN) could serve as a green substitute for ammonium perchlorate (AP) in halogen-free oxidizers. However, AN faces issues with endothermic phase transitions, melting, and sublimation. Ferric oxide, a common catalyst for solid propellants, was used to catalyze AN. This study reports the synthesis of 5 nm colloidal ferric oxide particles, integrated into the AN matrix through co-precipitation. Energy dispersive analysis by X-rays (EDAX) confirmed the proper dispersion of the ferric oxide catalyst. The impact of ferric oxide on AN decomposition enthalpy was assessed using differential scanning calorimetry DSC. Virgin AN showed an endothermic decomposition enthalpy of +1708 J/g, while catalyzed AN showed exothermic decomposition of −732 J/g. Ferric oxide nanocatalyst offered a decrease in AN main decomposition temperature by 83°C using thermogravimetric analysis (TGA). Activation energy dropped significantly, from 87.3 to 16.8 KJ/mol (Kissinger model), due to ferric oxide’s catalytic effect involving ferric and ferrous ion reactions.

Automated Workflow for Phase‐Field Simulations: Unveiling the Impact of Heat‐Treatment Parameters on Bainitic Microstructure in Steel

Bainitic steels are extensively utilized across various sectors, such as the automotive and railway industries, owing to their impressive mechanical properties, including strength, hardness, and fatigue resistance. However, the pursuit of achieving the desired optimal mechanical properties presents considerable challenges due to the intricate bainitic microstructures consisting of multiple phases. To tackle these challenges, an automated workflow is used for extracting 2D and 3D microstructural features. The proposed method allows for a detailed examination of the correlations between microstructure characteristics and the processing parameters, specifically the holding temperature during transformation. In these findings, it is revealed that as the holding temperature decreases, there is a notable reduction in microstructural element size and carbon partitioning. Some of the observations are microstructural features such as area, perimeter, and thickness of the bainitic ferrite grains under two different holding temperatures. Phase‐field simulations results show that the microstructures at lower holding temperatures have finer grains. The distributions of grain areas and perimeters are uniform, with smaller grains dominating at low and high isothermal holding temperatures. While the grain thickness measurements from simulations and experiments at high temperature are qualitatively aligned, data from low temperatures show discrepancies.

Enhancing Power and Thermal Gradient of Solar Photovoltaic Panels with Torched Fly-Ash Tiles for Greener Buildings

Solar photovoltaic (PV) panels that use polycrystalline silicon cells are a promising technique for producing renewable energy, although research on the cells’ efficiency and thermal control is still ongoing. This experimental research aims to investigate a novel way to improve power output and thermal performance by combining solar PV panels with burned fly-ash tiles. Made from burning industrial waste, torched fly ash has special qualities that make it useful for architectural applications. These qualities include better thermal insulation, strengthened structural integrity, and high energy efficiency. Our test setup shows that when solar PV panels are combined with torched fly-ash tiles, power generation rises by 7% and surface temperature decreases by 3% when compared to standard panels. The enhanced PV efficiency is ascribed to the outstanding thermal insulation properties of fly ash tiles and their capacity to control panel temperature. To ensure longevity and safety in building applications, the tiles employed in this study had a water absorption rate of 5.37%, flexural strength of 2.95 N/mm2, and slip resistance at 38 km/h. Furthermore, we find improved structural resilience and lower cooling costs when up to 30% of the sand in floor tiles is replaced with torched fly ash, which makes this method especially appropriate for sustainable buildings. Key performance indicators that show how effective these tiles are in maximizing energy use in buildings include thermal emissivity (0.874), solar reflectance (0.8), and solar absorption (0.256). While supporting more ecofriendly building techniques, this study highlights the advantages of utilizing burned fly ash in solar PV systems: enhanced power generation and thermal comfort. The main results open a greater potential for fly ash use in different building materials. The use of torched fly ash in building materials enhances thermal insulation and structural integrity while lowering cooling costs, making it an ideal choice for eco-friendly construction and highlighting the potential for further research into environmentally responsible, energy-efficient solutions.

Effect of COVID-19 global lockdown on our Moon

Abstract Systematic investigation of lunar night-time temperatures can possibly be thought as a stable platform to study Earth's radiation budget and climate change as advocated earlier by several researchers. In this study, we report an interesting observation possibly of changing Earth's climate as experienced by the Moon, utilising a rare and novel context of COVID-19 global lockdown. Lunar night-time surface temperatures of six different sites on the Moon's nearside were analysed during the period 2017–2023. Results showed an anomalous dip in the lunar night time surface temperatures for all the sites during April-May 2020, the strict COVID-19 global lockdown period, when compared to the values of the same period during the previous and subsequent years. Since the terrestrial radiation has also showed a significant reduction during that time, the anomalous decrease observed in lunar surface temperatures is attributed to the COVID 19 global lockdown effect. Therefore, our study shows that the Moon has possibly experienced the effect of COVID 19 lockdown, visualised as an anomalous decrease in lunar night-time surface temperatures during that period. These results can be substantiated further from Moon-based observatories in future, thereby making them potential tools for observing Earth's environmental and climate changes.

Temperature‐Dependent Recombination Dynamics of Photocarriers in CsPbBr3 Microcrystals Revealed by Ultrafast Terahertz Spectroscopy

AbstractThe ultrafast dynamics of photoexcited charge carriers are studied in micron‐scale crystals composed of the inorganic perovskite CsPbBr3 with time‐resolved terahertz spectroscopy. Exciting with photon energy close to the band edge, it is found that a fast (<10 ps) decay emerges in the terahertz photoconductivity with increasing pump fluence and decreasing temperature, dominating the dynamics at 4 K. The fluence‐dependent dynamics can be globally fit by a nonlinear recombination model, which reveals that the influence of different nonlinear recombination mechanisms in the studied pump fluence range depends on temperature. Whereas the Auger scattering rate decreases with decreasing temperature from 77 to 4 K, the radiative recombination rate increases by three orders of magnitude. Spectroscopically, the terahertz photoconductivity resembles a Drude response at all delays, yet an additional Lorentz component due to an above‐bandwidth resonance is needed to fully reproduce the data.

Cryogenic temperatures promote the pressure-induced polymorphic transition in CoCrFeMnNi high entropy alloy

Pressure-induced polymorphism has recently been demonstrated in several high entropy alloys. This offers a new window into the much-debated issue of phase selection and stability in these systems. Here, we examine the effect of cryogenic temperatures on the pressure-induced transition from face centered cubic to hexagonal close-packed structures of the prototype CoCrFeMnNi (Cantor) alloy. We observe a reduction in the critical pressure for the onset of the polymorphic transition as the temperature decreases, confirming the progressive stabilization of the hexagonal phase with decreasing temperature previously predicted by ab initio calculations accounting for magnetic interactions. We argue that in situ high-pressure experiments at cryogenic temperatures, which suppress time-dependent transformation triggered at higher temperatures, present a unique opportunity to significantly improve our understanding of these complex alloys.

Reversible Giant Barocaloric Effect with Broad Working Temperature Range in an Amorphous Ethylene Propylene Diene Monomer.

The barocaloric effect of a solid material is an intense research topic due to its potential application in solid-state refrigeration. Among the proposed candidates, elastic polymers are distinctive because their barocaloric responses are independent from a pressure-induced phase transition which makes it possible to realize a broad working temperature range in principle. However, the barocaloric performance of most elastic polymers diminishes significantly as temperature decreases. In this work, giant and reversible barocaloric effects were observed in a broad working temperature range from 252 to 345 K in an amorphous polymer of ethylene propylene diene monomer, which are much higher than the investigated crystalline and partially crystallized ones. It is demonstrated that the degree of crystallinity can be a key factor responsible for the mobility of polymer chains and the corresponding barocaloric performance at low temperatures. The reversible giant barocaloric effects, broad working temperature regions, low cost, and absence of pressure-transmitting fluid make the ethylene propylene diene monomer attractive for solid-state barocaloric refrigeration.

Development of predictive indices for evaluating the UHI adaptation potential of green roof- and wall-based scenarios in the Mediterranean climate

Urban heat islands can jeopardize urban inhabitants, but the installation of green roofs (GRs) and walls (GWs) can contribute to mitigating urban overheating. The present study provides novel indices to easily predict the spatial median variation in air temperature at pedestrian heights related to the application of GR- and GW-based scenarios during the hottest hours of a typical summer day by varying the building height (BH), coverage percentage, and leaf area index. The indices are meant to be applied to built areas with 0.3–0.4 urban density in the Mediterranean climate and are derived from regression models fed with the outputs of 281 simulations of three urban areas developed and run in ENVI-met software. The developed models are all highly significant. The GR model shows that mitigation is influenced by all three parameters, and it can estimate mitigation with a root mean square error of 0.05 °C. Compared with the other parameters, the GW models revealed that the BH did not influence the decrease in air temperature. The green façade and living wall (LW) indices predict mitigation with errors of 0.04 °C and 0.05 °C, respectively. However, for the LW model, further parameters should be considered to improve its reliability.

Improving hypercrosslinked polymer CO2/N2 selective separation through tuning polymer's porous properties: Optimization using RSM-BBD

This study investigates the effect of synthesis and operating parameters on the adsorption of CO2 and N2 and the CO2/N2 selectivity of a hypercrosslinked adsorbent based on waste-expanded polystyrene. Six factors were examined, including synthesis time, crosslinker and catalyst amounts, adsorption temperature and pressure, and CO2 percentage in the mixture. The response surface methodology (RSM) and ideal adsorbed solution theory (IAST) were employed to design the experiment. After synthesizing 19 adsorbents under different conditions, characterization tests were conducted. Results indicate that the specific surface area and micropore volume initially increase and then decrease with increased synthesis time, crosslinker, and catalyst amounts. The highest specific surface area and micropore volume were 803.84 m2/g and 0.1355 cm3/g, respectively. CO2/N2 selectivity and the adsorption of CO2 and N2 also increase and decrease with increased synthesis parameters. Furthermore, it was observed that CO2 adsorption and CO2/N2 selectivity increased with an increase in pressure and CO2 percentage and a decrease in temperature, while N2 adsorption decreased. The adsorbents were optimized using RSM to maximize CO2 adsorption and CO2/N2 selectivity with a target of 15 % CO2 in the gas mixture. The optimal synthesis parameters for the hypercrosslinked adsorbent, including synthesis time, crosslinker, and catalyst amounts, were determined to be approximately 13 hours, 30 mmol, and 30 mmol, respectively. Under optimal conditions for flue gas applications (CO2:N2/15:85), the adsorbent demonstrated a CO2/N2 selectivity of 11.05, making it suitable for flue gas capture.

Highly efficient multi-layer flexible heatsink for wearable thermoelectric cooling

Flexible thermoelectric cooler (fTEC), which interfaces well with curved human body surface and provides cooling functions, is an emerging candidate for personal thermal management and non-hospitalized medical treatment. Achieving efficient and long-term cooling performance of TEC requires high thermal conductivity and heat diffusion of the hot side, which has yet to achieve. In this study, we design and fabricate a highly thermally conductive and flexible heatsink with a multi-layered structure especially for wearable TEC wristband, which obtains a large temperature drop (8.8 °C) for imitated on-body test and the maxim 13.1 °C temperature decrease in air. Here, we demonstrate that a well-designed functional composite layer, including phase change material, thermally conductive fillers and metal foam, can establish an effective equilibration among cooling performance, thermal management capacity and mechanical property. Particularly, the heatsink with highly thermal conductive skeleton (k ∼ 2.7 W/mK) and effective heat dissipating fins can significantly improve heat conduction and dissipation, which improve the cooling performance by more than 55 %. With the help of theoretical simulation, we propose a promising strategy for heat management on thermoelectric device through a flexible multi-layered structure, paving the way for achieving practical applications of wearable thermoelectric coolers for personal thermal regulation or cooling therapy.

Investigations on the Heat Balance of the Melt Pool during PBF-LB/M under Various Process Gases

During the powder bed fusion of metals using a laser beam (PBF-LB/M), an inert atmosphere is maintained in the build chamber to avoid reactions of the liquid metal with ambient air leading to the creation of oxides or nitrides, which alter the mechanical properties of the processed part. A continuous gas flow is guided over the process zone to remove spatters and fumes. This flow induces a convective heat transfer from the molten metal to the gas, which, depending on the level of the heat flow, may alter the melt pool dimensions by influencing the cooling rate. The present work investigated these phenomena with single-line trials, both experimentally and numerically. For this reason, a smoothed-particle hydrodynamics model was utilized to investigate the temperatures of the melt pool, cooling rates, and the integral heat balance with various gas atmospheres. In parallel, an on-axis pyrometer was set up on an experimental PBF-LB/M machine to capture the surface emissions of the melt pool. The atmosphere in the simulations and experiments was varied between argon, helium, and two mixtures thereof. The results showed a slight increase in the cooling rates with an increasing fraction of helium in the process gas. Consistently, a slight decrease in the melt pool temperatures and dimensions was found.

Study on the effect of condenser configuration of pulsating heat pipes for space applications

In this study, the effect of condenser configuration on the thermal performance of pulsating heat pipes (PHPs) for space applications is experimentally investigated. The thermal performances of a single-condenser PHP and double-condenser PHP are compared under the constraints of the same evaporator and condenser areas. The PHPs are composed of a meandering channel with 30 turns and are made of a stainless-steel tube with the inner and outer diameters of 1.0 and 1.6 mm, respectively. R-134a is used as the working fluid, and the filling ratio is varied from 30 % to 60 %. Under various experimental conditions, the thermal performances of both single- and double-condenser PHPs are examined from two perspectives. First, the thermal resistances of the two PHPs are compared across a range of condenser temperatures from 10 to 30 °C and heat inputs from 0 to 700 W. According to the experimental observations, the double-condenser PHP exhibits a considerable reduction in thermal resistance, up to 55 % compared with the single-condenser PHP, across all the experimental conditions. Second, the operating ranges of the two PHPs are compared. For the single-condenser PHP, either an increase in the filling ratio or a decrease in the condenser temperature results in a narrower range of stable operation, with a maximum allowable heat input of approximately 200 W. On the other hand, the double-condenser PHP is mostly in the stable operating region regardless of the filling ratio or condenser temperature. Consequently, it exhibits an operating range approximately four times wider than that of the single-condenser PHP, indicating a significantly expanded range of stable operation. These improvements in thermal performance can be attributed to having the effects of doubling the number of evaporator-condenser pairs and halving the length between the evaporator and the condenser.

Investigation of P2O5 on the Break Temperature and Phase Composition of Slag from the Double Slag Converter Steelmaking Process

Herein, the influence of P2O5 on the break temperature and phase composition of slag from the double slag converter steelmaking process is investigated comprehensively. The composition and micromorphology of crystallized phase are analyzed by X‐Ray diffractometer and scanning electron microscope equipped with energy dispersive spectrometer. The results reveal that the break temperature of slag increases owing to an increase of P2O5 content. When the P2O5 content is 2%, the break temperature is 1198 °C, and it increases to 1209 °C for the slag with 4% P2O5. With the increase of P2O5 content from 2% to 8%, the activation energy for viscous flow shows an upward trend. The crystallized phase at the same temperature with different P2O5 contents remains nearly unchanged, but the diffraction peak intensity is different. When the P2O5 content remains constant, a decrease in temperature results in significant changes in the micromorphology of crystallized phases. The present results improve the knowledge about the P‐rich slag, and are also significant in optimizing the double slag converter steelmaking process.

<i>Solanum tuberosum</i> L. phytoene synthase genes (<i>StPSY1, StPSY2, StPSY3</i>) participate in the potato plant’s response to cold stress

The structure and phylogeny of the genes StPSY1, StPSY2 and StPSY3, encoding phytoene synthases from Solanum tuberosum L., were characterized. The expression of these genes in potato seedlings was studied in response to exposure to cold stress in the dark phase of the diurnal cycle as an imitation of night cooling. It was found that all three genes are activated when the temperature decreases, and the greatest response is observed for StPSY1. The response of the StPSY3 gene to cold stress and photoperiod has been demonstrated for the first time. A search was carried out for cis-regulatory elements in the promoter region and 5´-UTR of the StPSY genes and it was shown that the regulation of all three genes is associated with the response to light. The high level of low-temperature activation of the StPSY1 gene may be associated with the presence of cis-elements associated with sensitivity to cold and ABA.

Justification of the possibility of using liquid artificial lung ventilation for the treatment of acute respiratory distress syndrome of toxic genesis

Introduction. Pulmonotoxicants are chemicals that cause bronchospasm and damage to the alveolar capillary membrane. Lesions of the respiratory system with pulmonotoxicants in industrial accidents are especially relevant at the present time. Existing methods of treatment for the defeat of pulmonotoxicants and the development of acute respiratory distress syndrome (ARDS) are becoming ineffective, therefore, one of the tasks of modern medicine is to develop new methods of treating ARDS. One of these methods may be the creation of a "therapeutic window" by using perfluorocarbon (PFC) liquids. This article will present an experimental assessment of the use of liquid artificial lung ventilation (LALV) PFC liquids on the ARDS lung model. The study aims to explore the possibility of using liquid artificial lung ventilation to create a therapeutic window in the treatment of acute respiratory distress syndrome of a chemical nature. Materials and methods. The authors conducted a study on male Wistar rats aged 4 months, weighing 180–190 g. Toxic pulmonary edema was caused by endotracheal administration of 0.1 m HCl solution. The anesthetized patients were intubated using a cannula, after which the researchers intratracheally injected 0.1 M HCl solution at a dose of 2 ml/kg, a decrease in saturation below 80 was expected. Then the experts randomized the animals by weight into groups of 6 individuals each. They connected the animals of the control group to a ventilator. The animals of the experimental group were treated with PFC liquids for an hour, then transferred to a ventilator. Perfluorodecalin was used as a PFC liquid. The scientists recorded heart rate, blood oxygen saturation, rectal temperature, life expectancy and overall survival by group. Results. In the control group, after instillation of 0.1 M HCl solution and connection to a ventilator during the first 25–30 minutes, there was a gradual decrease in SpO2 to 74.0±5.6% (background — 95.0±3.5%) and an increase in heart rate to 182.0±8.6 beats/min., (background — 278.0±14.8 beats/min.) after which there was decompensation of the animal condition. In animals of the experimental group, after connecting to the LALV device, a sharp decrease in heart rate was recorded during the first 5 minutes to 61.0±8.5 beats/min. In turn, saturation did not change significantly throughout the LALV and was in the range from 95 to 100%. As a result of the experiments, it was noted that the average survival time in the experimental group was 256.0±34.5 minutes, which was significantly (p<0.001) more than 5 times higher than this indicator in the control animals — 45.3±4.3 minutes. There were no significant changes in the study of rectal temperature in the animals of the control group. In turn, the animals of the experimental group showed a sharp decrease in rectal temperature during the first 30 minutes from the beginning of LALV, on average by 5.8±1.60°С. As a result of the pathoanatomic autopsy, differences in lung mass coefficients were revealed in different groups. Thus, in the control group and the experimental groups, it was 1.67±0.06 and 2.4±0.045%, respectively. Conclusion. On the model of ARDS caused by endotracheal administration of 0.1M hydrochloric acid solution, it was shown that living with the use of PFC of low temperature liquids, unlike conventional mechanical ventilation, allows for a long time to maintain a stable condition of animals; evacuate a significant amount of edematous fluid from the lungs and thereby increase the duration of their survival. The data presented above indicate that the use of hypothermic LALV can be used to create a "therapeutic window" for ARDS, including its most severe form — the alveolar stage of toxic pulmonary edema. Ethics. Studies involving laboratory animals were conducted in compliance with the following regulations: the Helsinki Declaration of 2000 "On humane treatment of animals", Order No. 755 of the Ministry of Health of the USSR dated 08/12/1977 "Rules for carrying out work using experimental animals", Order No. 199n of the Ministry of Health of the Russian Federation dated 04/01/2016 "On approval of the rules of laboratory practice". The protocol of the study was approved by the Ethics Committee of the Izmerov Research Institute of Occupational Health. Protocol No. 4 dated May 25, 2022.

Wetting Preference of Silica Surfaces in the Context of Underground Hydrogen Storage: A Molecular Dynamics Perspective.

The growing interest in large-scale underground hydrogen (H2) storage (UHS) emphasizes the need for a comprehensive understanding of the fundamental characteristics of subsurface environments. The wetting preference of subsurface rock is a crucial parameter influencing the H2 flow behavior during storage and withdrawal processes. In this study, we utilized molecular dynamics simulation to evaluate the wetting preference of the silica surface in subsurface hydrogen systems, with the aim of addressing disparities observed in experimental results. We conducted an initial comprehensive assessment of potential models, comparing the wettability of five common silica surfaces with different surface morphologies and hydroxyl densities in CO2-H2/water/silica systems against experimental data. After introducing the INTERFACE force field as the most accurate potential model for the silica surface, we evaluated the wetting behavior of the α-quartz (101) surface with a hydroxyl density of 5.9 number/nm2 under the impact of actual geological storage conditions (333-413 K and 10-30 MPa), the coexistence of cushion gases (i.e., CO2, CH4, and N2) at various mole fractions, and pH levels ranging from 2 to 11 characterized through considering the negative charges of 0 to -0.12 C/m2 via deprotonation of silanol on the silica surface. Our results indicate that neither pressure nor temperature has a significant impact on the wetness of the silica in the case of pure H2 (single component UHS operations). However, when CO2 coexists with H2, especially at higher mole fractions, an increase in pressure and a decrease in temperature lead to higher contact angles. Moreover, when the mole fraction of cushion gas ranges from 0 to 1, the contact angle increases 20, 9.5, and 4.5° for CO2, CH4, and N2, respectively, on the neutral silica substrate. Interestingly, at higher pH conditions where the silica surface carries a negative charge, the contact angle considerably reduces where surface charges of -0.03 and -0.06 C/m2 result in an average reduction of 20 and 80% in the contact angle, respectively. More importantly, at a pH of ∼11 (-0.12 C/m2), a 0° contact angle is observed for the silica surface under all temperatures, pressures, types of cushion gases, and varying mole fractions.

Local atomic configuration and dynamic properties of liquid Ag-Si eutectic alloy by ab initio molecular dynamics

The structural evolution and dynamic properties of liquid Ag89Si11 eutectic alloy during rapid cooling were explored by ab initio molecular dynamics. The calculated pair distribution functions and structure factors at 1173 K agree well with the experimental reference data. The comprehensive analyses including Honeycutt-Andersen index, Voronoi tessellation, and atomistic cluster alignment reveal a gradual enhancement of chemical short-range order with the decreasing temperature and a dominant structural shifting towards perfect and distorted icosahedra. Additionally, the dynamic properties of liquid Ag89Si11 eutectic alloy were obtained and the diffusion coefficients follow Arrhenius relationship.

Interface stabilization strategy realizing low-temperature sodium storage in Sb anode prepared by ball milling method

Antimony (Sb) is an attractive anode material for sodium-ion batteries (SIBs) owing to its low operating potential, low cost, and high theoretical capacity. However, the large volume expansion of Sb during the Na alloying/dealloying process, which greatly limits its application in SIBs. Simultaneously, as the temperature decreases, the formation of a poor coating on the anode surface significantly increase the difficulty of Na+ transmission. Herein, Sb-graphite-NaF (SCF) ternary composites were prepared by an easy to operate and low-cost ball milling method, which significantly improved the cycling stability and extended to the operation temperature of Sb-base SIBs. A small amount of NaF induces the formation of an inorganic-dominated NaF-rich stable solid electrolyte interphase (SEI) on the Sb anode surface, which can cooperate with graphite to inhibit volume expansion of the Sb particles during sodium storage, enhance conductivity and accelerate Na+ diffusion at room and low temperatures. As a result, the SCF electrode with propylene carbonate-base electrolyte delivered a discharge capacity of 458.4 mAh g−1 after 160 cycles at 500 mA g−1 at 20 °C. When matched with diethylcarbonate-based electrolyte at −20 °C, it had a specific capacity of 299.8 mAh g−1 after 120 cycles and a capacity retention rate of 86.2 %. This study shows that the interface stabilization strategy with a suitable electrolyte can improve the cycling stability of anode materials, provide a new idea for constructing NaF-rich SEI, and a new approach for applying Sb-based materials in low-temperature SIBs.

Experimental study on fracture failure characteristics evaluation of wooden pallets in humid-cold environment based on piezoelectric technology

Wooden pallets often suffer mechanical damage during transportation, stacking, forklifting, and on-site handling in cold supply chain logistics. In humid-cold environments, the fracture properties of wooden pallets change, increasing the risk of sudden fracture failure. Understanding the fracture failure characteristics of wooden pallets is essential to prevent further damage to goods. Nevertheless, evaluating and identifying these characteristics currently presents significant challenges. This study investigates the changes in modulus of elasticity (MOE) and fracture failure characteristics including modulus of rupture (MOR), brittleness and toughness of wooden pallets and impact toughness of wood material under humid-cold conditions. The piezoelectric technology was applied to evaluate and identify fracture risk of wooden pallets used in various humidity and cold conditions. Quarter-sized wooden pallets and standard wood specimens were examined by laboratory study. The experimental results showed that the MOE, MOR, toughness of wooden pallets and impact toughness of wood with higher moisture content (MC) increased with decreasing temperature, while brittleness increased as temperature decreased. These results indicate that the maximum carrying ability of wooden pallets increases in humid-cold environments while the ability to resist fracture was reduced with a higher brittle rupture risk. The toughness and its corresponding piezoelectric voltage exhibited good consistency with changes in temperature and MC. The relationship between toughness and piezoelectric voltage was established with good coefficient of determination (over 0.81). It indicates that the risk of wooden pallets could be predicted effectively using piezoelectric technology.