Storage Rate Research Articles

Dependence of the hydrate-based CO2 storage characteristics on sand particle size and clay content in unconsolidated sediments

Storing carbon dioxide (CO2) in the form of hydrate in marine sediments is considered an effective way of carbon reduction. Understanding the influence of sediment properties on CO2 hydrate formation is important for the site selection of CO2 hydrate storage in marine sediments. In this study, the effects of sand particle size and bentonite content on the kinetics of CO2 hydrate formation are analyzed using low-field nuclear magnetic resonance technology, and the hydrate-based liquid CO2 storage capacity is evaluated. Results show that CO2 hydrate forms preferentially in large pores of sand samples, the water content in small pores begins to decrease before the hydrate saturation reaches 20%, and the unhydrated water mainly concentrates in small pores. With the increase of sand particle size, the CO2 storage rate of the early rapid growth stage increases first and then decreases, the CO2 storage rate of the whole hydrate formation process decreases continuously, but the final CO2 storage density is weakly affected by sand particle size. With the increase of hydrate saturation, the CO2 storage rate undergoes a trend of rapid decrease, stability, rapid decrease, and low-speed decrease in sequence. The larger the sand particle size or the higher the bentonite content, the shorter the stability stage of CO2 storage rate. The effect of bentonite on CO2 storage rate is the promotion at low content, the inhibition at medium content, and the weakening of inhibition at high content. The sediments with more than 25% bentonite are beneficial to the storage of more CO2.

Performance Evaluation of Directional Porous Oil Storage Medium Fabricated by PTFE and Naphthalene

Porous oil storage media is the core of self-lubricating rolling functional components. The internal pore directivity of porous oil storage media is different，and it reduces the utilization rate of lubricating oil. In this paper, a new fabrication method of porous oil storage media with directional pores is carried out, and the properties of the porous media, such as hardness, density, porosity, oil storage rate and oil retention rate are evaluated. The experimental results show that the fabrication pressure has a linear positive effect relationship with the hardness of the porous media, and has no significant effect on the density, porosity, oil storage rate and oil retention rate. The mass fraction of pore former has a linear negative effect relationship with the hardness and density of the porous media, and a linear positive effect relationship with the porosity the greater the mass fraction of pore former, the greater the initial oil seepage rate of oil rejection. The internal pores of the porous media have a fibrous structure of the karst cave type, and the internal pores are interconnected and have good orientation. This study aims to provide a lubricating theoretical reference for the fabrication of porous oil storage media.

Phase change material performance in chamfered dual enclosures: Exploring the roles of geometry, inclination angles and heat flux

This study presents a comprehensive thermal performance analysis of phase change materials (PCMs) within a chamfered dual enclosures subjected to constant heat flux. Utilizing numerical simulations, we investigate the impact of various PCM types, inclination angles (α = 0°, 15°, 30°, 45°, 60°, 75°, 90°), and heat flux levels (Q = 500, 1000, 1500, 2000 W/m²) on melting rates, temperature distribution, and energy storage efficiency. The study examines commercially available PCMs, including RT-25, RT-27, RT-31, RT-35, RT-38, RT-42, RT-47, and RT-50. Our findings reveal that the inclination angle significantly influences thermal performance, with optimal performance observed at angles between 45° and 90° The PCM at 45° exhibited the fastest melting rate and demonstrating the highest energy storage efficiency. Among the PCMs, RT-27 showed the slowest temperature increase, while RT-50 exhibited the highest heat absorption efficiency and rapid temperature rise, making it suitable for applications requiring quick thermal management. Additionally, higher heat flux levels accelerated the phase transition process, with melting rates increases higher at 2000 W/m² compared to 500 W/m². The energy storage capacity varied, with RT-47 and RT-50 demonstrating the highest storage rates, while RT-27 was effective for sustained thermal energy release despite its slower phase change rate. This research bridges gaps in the existing literature by integrating various parameters and providing a holistic understanding of PCM behaviour in thermal energy storage systems. The insights gained from this study can inform the design and optimization of PCM-based thermal management solutions across various applications, including solar heating systems, electronic device cooling, and industrial waste heat recovery.

Ball-Milling-Assisted N/O Codoping for Enhanced Sodium Storage Performance of Coconut-Shell-Derived Hard Carbon Anodes in Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are regarded as cost-effective alternatives or competitors to lithium-ion batteries for large-scale electric energy storage applications. However, their development has been hindered by the high cost of hard carbon (HC) anodes and poor electrochemical performance. To enhance the sodium storage capacity and rate performance of HC, this study accelerated the electrochemical performance of coconut-shell-derived HC anodes for SIBs through N/O codoping using ball milling and pyrolysis. Experimental results demonstrate that the simultaneous introduction of N and O generates a synergistic effect, increasing the surface oxygen-containing functional groups, defects, and interlayer spacing of coconut-shell-derived HC through the codoping of light elements. The excellent strategy has increased the slope capacity and platform capacity of HC, and the synergistic modification of N/O has increased its reversible specific capacity from 272 to 343 mA h g-1 (30 mA g-1), with a retention rate of approximately 92.1% after 100 cycles. In addition, it also exhibits an excellent rate performance, reaching 178 mA h g-1 at 1500 mA g-1. In summary, this study presents an effective strategy for modifying biomass-derived HC.

Study on heat storage characteristics and carbon optimisation in the sintering process

In response to the phenomenon of automatic heat storage during the sintering process of iron ore, heat balance analysis concerning the main chemical reactions and physical heat carried by gas and solid materials was conducted. A unit heat storage model for the sintering process was established. Further, a mathematical model to solve the heat transfer characteristics between different sintering layer units was proposed and established based on temperature–time curves of the gas and solid phases. Using these models, the heat storage of each layer unit was calculated under the condition of uniform carbon allocation. Subsequently, the optimisation of carbon allocation at each layer unit for maximising the utilisation of heat storage was investigated. The heat required for sintering by the layer unit was taken as the constraint, and the maximum utilisation of heat stored in each layer unit was taken as the goal to optimise the carbon allocation in the height direction. The calculation results show that as the unit thickness is 100 mm and the total thickness of the layer is 600 mm, the heat transfer ratio of the upper unit to the lower unit is 34.22%, 30.29%, 14.74%, 9.49%, and 1.17%, respectively. The heat storage and available heat storage rate increase with the increase of layer height, with heat storage ranging from 0.69 × 104 to 5.14 × 104 KJ/t and heat storage rate ranging from 11.63% to 49.37%. After optimising carbon allocation, the unit achieved a maximum carbon reduction of 60.04%, resulting in an overall reduction in carbon allocation of 46.20%. This adjustment aligns more closely with the industrial processes.

Improving the charging performance of latent heat thermal energy storage systems using triply periodic minimal surface (TPMS) structures

The utilization of latent heat thermal energy storage (LHTES) using phase change materials (PCM) has attracted considerable attention due to their high energy density and thermal regulation. However, the inferior thermal conductivity of PCM has hindered their widespread implementation, triply periodic minimal surface (TPMS) structures could considerably ameliorate the energy storage utilization. TPMS structures offer escalated surface area and pore interconnectivity, which can enhance the apparent thermal conductivity and improve the performance of LHTES systems. This study focuses on investigating the performance and storage capabilities of three unique TPMS structures, namely Gyroid, IWP, and Primitive, at different relative densities and charging temperatures. The computational model is developed, verified, and validated with the relevant experiment results. A comparative analysis of the temperature distribution and liquid fraction evolution in TPMS LHTES units is carried out and compared to pure PCM LHTES. At a charging temperature of 80 °C, compared to the complete melting time of 7206 s for the pure PCM LHTES, the results demonstrate that the G10, IWP10, and P10-PCM LHTES achieve complete melting at 344 s, 276 s, and 368 s, respectively. This affirms the superiority of IWP structures in improving the melting rates due to their escalated surface areas and tortuous paths. The use of TPMS structures improves the total heat storage, heat storage rate, and volumetric heat storage density, while reducing the gravimetric heat storage density, compared to the pure PCM LHTES. The G10-PCM LHTES attains total heat storage, heat storage rate, volumetric, and gravimetric heat storage density of 2120 J, 6.16 W, 63.6 kWh/m3, and 227 kJ/kg, compared to 1910 J, 0.27 W, 57.3 kWh/m3, and 250 kJ/kg for pure PCM LHTES, respectively. Moreover, increasing the relative density of TPMS structures adversely reduces the total heat storage, heat storage rate, and volumetric heat storage density, and significantly increases the heat storage rates. As the charging temperature increases, the complete melting time is reduced and the charging performance indicators are improved, for the pure PCM and TPMS-PCM LHTES units.

Experimental study on an improved direct-contact thermal energy storage container

Direct-contact thermal energy storage (TES) systems characterized by high heat density and rapid heat transfer rates have been exploited for the collection of industrial waste or surplus heat for subsequent utilization. In order to address blockage issue at the initial stage of charging process, an improved direct-contact TES container was developed by incorporating a double-pipe structure at both the inlet and outlet. Within the container, a U-shaped tube serving as the inner tube was concentrically positioned from the inlet to the outlet. Erythritol was selected as the phase change material (PCM), while heat transfer oil (HTO) functioned as the heat transfer medium during experimentation. During the charging process, hot HTO initially flowed through the U-shaped tube, establishing an indirect contact with the PCM. The high thermal conductivity of the U-shaped tube wall expedited the formation of a flow channel within the solid PCM. The duration of forming flow channel was 6 to 13 min. In the discharging phase, the liquid PCM was segregated into convection and conduction zones. The indirect-contact TES experiments were also conducted in the same container. Comparison between indirect-contact and direct-contact TES were analysed from the aspects of phase change behavior, charging and discharging time with the identical container structure and theoretical heat capacity. Results indicated that the direct-contact TES container exhibited superior heat storage and release rates, with the direct-contact discharging time being approximately a quarter of the indirect-contact duration. The phase change behavior of the PCM was notably influenced by the movement of HTO within the direct-contact storage container.

Simulation of solidification for saving energy with using nanomaterial involving conduction heat transfer

The current article studies the improvement of the discharging rate in cold storage systems by modifying the tank configuration and incorporating additives. Specifically, the study inspects how varying the diameter (dp) and fraction (ϕ) of nano-powders affects the process duration. The governing equations, derived under the assumption of negligible slip velocity of nanoparticles and convection terms, were solved using the Galerkin method. The computational grid was modified owing to location of the ice front, and unsteady terms were discretized using an unconditionally stable approach. The results indicate that initially, increasing dp decreases the process duration by approximately 20.01 %, but further increases in dp lead to a 49.53 % rise in the duration. As the process time increases, the amount of ice produced also increases, with nanoparticle loading resulting in a significantly higher ice yield. Specifically, the incorporation of nanoparticles enhances the storage rate by approximately 41.37 %.

Proximity to inlet channel drives spatial variation in sediment carbon across a lagoonal seagrass meadow

Seagrass meadows can be sinks for organic carbon, but estimates of global organic carbon stocks are complicated by substantial spatial variability in organic carbon burial observed within meadows. To improve estimates of organic carbon burial in seagrass meadows, it is necessary to understand the causes of the spatial heterogeneity. This study investigated relationships between spatial patterns in sediment organic carbon storage and accretion rates, hydrodynamics, and proximity to sources of organic carbon in a current-dominated Zostera marina Linnaeus meadow in Menemsha Pond, Massachusetts, USA. Sediment and velocity measurements were conducted at six stations along a 150-m transect across the meadow oriented perpendicular to the pond's unvegetated inlet channel. The meadow's edge near the channel had higher organic carbon than the channel as well as the highest organic carbon within the meadow. With increasing distance from the meadow's edge, all of the following decreased: sediment organic and total carbon, sediment accretion rates, peak tidal velocity, sediment trap mass deposition rate, and the relative contribution of non-seagrass sources to sediment organic carbon. Lower tidal velocities farther from the inlet channel reduced sediment resuspension, consistent with lower sediment trap mass deposition, which should enhance organic carbon content and organic carbon accretion rates. However, the opposite trend of decreasing organic carbon content (>50 % across the transect) and decreasing accretion rates with distance from channel was observed. This suggested that the local hydrodynamic intensity was not controlling organic carbon accretion, which was instead constrained by supply limitation and controlled by the lagoon-scale flow circulation.

A Twin Spiral Coil Phase Transfer Heat Exchanger for Storing Heat Should Be Designed and Tested in The Lab.

Abstract This in-depth study of thermal energy storage (TES) systems examines their function in resolving time, temperature, power, and location problems within the immense energy system design. With its incredible growth, TES creates a shadow over the future, projecting optimism for a better economy and more reliable energy infrastructure. The study is concentrated on a state-of-the-art heat exchanger that has circular double coils with various diameters, with a reliance on charging process amplification. The trial stage is decorated like a well-coordinated ensemble, integrating shell-and-tube design together with intense evaluation of varied tube morphologies, HTF flow designs, and protecting processes. The TES device effortlessly reveals its many components, such as a gas heater, control valves, a pump, a circular container with spiral HTF tubes, and a chorus of music. The PCM heat storage unit’s performance improved in two resonant cases that evaluated the effect of the HTF input temperature and coil charge in great detail. Case 2 and Case 1’s connections exhibit the significant heat absorption and PCM liquification by creating a web of various temperature differences while charging. With its improved temperature performance and straightforward design, Case 2 displays rapid removal and quicker charging periods. In addition, the study examines the HTF input parameters, which cast light on the constant HTF departure temperatures and demonstrate the importance of temperature during the charging opera. While the total energy storage rate rises with increasing temperatures, the expected scores are in accord with the mood fluctuations at the beginning and end of HTF. This review functions as a folder of vital insights, analyzing notes towards constructing PCM charging processes for higher energy storage efficiency - ultimately placing a limelight on the endless possibilities that TES systems predict in the present spectrum of energy uses.

In situ anchoring of FeNi nanoparticles into three-dimensional nitrogen-doped carbon framework as a self-supporting electrode for high-performance lithium storage

Constructing free-standing electrodes with superior lithium storage capacity and good mechanical performance are fascinating for next-generation lithium-ion batteries (LIBs). Nevertheless, their practical application is hindered by complicated synthesis procedures and high cost. Herein, a highly stable, self-supporting and flexible electrode material for LIBs was constructed by encapsulating spherical FeNi nanoparticles into one-dimensional N-doped carbon fiber film (FeNi/N- CFM) using the electrospinning technique and subsequent heat treatment. The FeNi/N-CFM can be directly used as anode materials for LIBs without conductive additive, current collector and binder. The synergistic effect of uniformly dispersed small FeNi nanoparticles and three-dimensional (3D) conductive network constructed by CF framework effectively improves the utilization rate of active materials, enhances the transport of both electrons and lithium ions, facilitates the electrolyte penetration, and promotes the lithium-ion storage kinetics and stability, thus leading to a greatly enhanced electrochemical performance. Benefiting from the unique architectural feature and flexibility, the FeNi/N-CFM composites employed as binder-free electrodes for LIBs exhibit good lithium storage performance (an initial discharge capacity of 1031.5 mA h g−1 and a reversible capacity of 481.3 mA h g−1 at 100 mA g−1 after 100 cycles), rate capacity (305.1 mA h g−1 at 1000 mA g−1) and outstanding reversibility (coulombic efficiency of around 100 % after 100 cycles). Furthermore, this work also provides a facile and effective pathway to design and fabricate free-standing electrodes.

Nickel doped tungsten disulfide grown on carbon cloth for flexible supercapacitors

We present the synthesis of flower-shaped nickel-doped tungsten disulfide on flexible activated carbon cloth (ACC) using a simple hydrothermal technique for flexible symmetric supercapacitors. The nickel-to-tungsten disulfide doping ratio is optimized by adjusting the mass ratio of nickel and tungsten disulfide (Ni:WS2 = 0.5:3, 1:3, and 1.5:3) to enhance charge storage capability, surface area, impedance behavior, specific capacity, and rate capability. The improved supercapacitor performance is attributed to the increased electrochemically active surface area, reduced impedance, and phase engineering from 2 H to 1 T achieved through optimal nickel doping. At a current density of 1 A g−1, the flexible symmetric supercapacitor device (Ni-WS2-ACC device) demonstrates a specific capacitance of 259.2 F g−1, an energy density of 22.4 Wh kg−1, and a power density of 803 W kg−1. Moreover, the Ni-WS2-ACC device maintains consistent supercapacitive performance under various bending conditions. These results present a promising strategy for further enhancing tungsten disulfide-based flexible supercapacitors as energy storage devices.

Nanosizing strategy to fabricate uniformly dispersed NiO/Ni/lignin porous carbon composites for high lithium storage

Nickel oxide is considered a promising anode material for lithium-ion batteries. Nevertheless, its performance is hindered by significant volume expansion and low electrical conductivity, particularly at larger particle sizes, which lead to a notable decrease in lithium storage capacity and rate performance. To address these challenges, we introduce a nanocomposite strategy to synthesise nickel oxide and lignin-derived porous carbon composites (LPC/Ni/NiO). Through in situ polymerization, lignin macromolecules form a uniform 3D network with nickel carbonate, which, during the subsequent carbonisation process, results in the formation of nickel oxide within a conductive carbon network. This approach reduces the nickel oxide to nanosize and enhances the composite's electrical conductivity, effectively integrating the buffering framework of porous carbon with the high storage capacity of nickel oxide. As a result, the LPC/Ni/NiO composite exhibited significantly improved lithium storage capacity. Notably, when employed as an anode material in lithium-ion half-cells, the optimized composite maintained an excellent specific capacity of 1065 mAh/g after 100 cycles at a current density of 0.2 A/g. It also shown exceptional rate performance, delivering a specific discharge capacity of 505 mAh/g at a current density of 2 A/g, with stable cycling performance. The electrochemical reaction process was further validated using in ex-situ EIS. This study offers valuable insights into scalable synthesis methods for oxide nanocomposites, highlighting their potential as promising anode materials for lithium-ion batteries.

Solar thermal cooking device for domestic cooking applications: Bridging sustainable development goals and innovation

Fossil fuels are vital in the cooking field rather than the automotive sector. Hence, solar cooking has been popularized in recent years due to the rising cost of cooking gas. However, implementing successful renewable energy for cooking in urban area is still challenging for industries. Hence, a solar thermic cooking device with a compact size suited for domestic cooking in urban area is proposed. Thus, the solar cooking device will be developed as a fully functional prototype with necessary supporting modules, depending on the heat transfer fluid (HTF) flow and heat transfer rate between fluids. The main objective is to represent various computational fluid dynamics (CFD) and thermal analysis results on different optimistic designs for a solar thermoelectric cooking device's heat exchanger and storage unit. The 3D part model of the modules has been developed using SOLIDWORKS 2019 software. CFD has also been carried out using the same workspace with an additional package called flow simulation to analyze the flow properties of heat transfer fluid at different rates when circulated in other modules.Moreover, the thermal behavior of the HTF concerning the heat transition between module surfaces is simulated using SOLIDWORKS flow simulation to evaluate the heat storage capacity and rate of heat transfer. The theoretical formulations for the modules are derived through thermodynamic equations concerning the materials and fluid involved in the unit. The thermal and CFD analysis is carried out for different optimistic 3D models based on thermal sustainability, and the results are compared with theoretical analysis, which is discussed in this paper.

Oil storage and debrining process in insoluble sediment voids for underground salt cavern energy storage: An experimental study

Large salt cavern oil storage is an effective underground oil storage method, which has been widely used in the United States, Germany, and France. However, the insoluble impurity sediment particles at the bottom of the salt cavern will occupy plenty of oil storage space. To enhance the oil storage capacity, the sediment void oil storage (SVOS) method was proposed. The debrining process from the sediment void prerequisite of the SVOS. It will affect the feasibility of oil injection into the sediment void and the operation efficiency of SVOS. Thus, a self-made debrining device of SVOS was built, and the dynamic debrining process in the sediment void was investigated to explore the debrining process from the sediment void. Six debrining parameters (oil-brine interface change, oil injection rate, brine discharge rate, oil viscosity, the second oil injection quantity, and ground temperature) were proposed and considered. Two kinds of oils (diesel and petrolatum) were conducted in the SVOS debrining experiments. The experimental results showed that the debrining rate remained stable, and it was relevant to the oil injection rate and the interaction of oil and sediments. The average debrining rate of the initial diesel debrining, second diesel debrining, and petrolatum debrining were 2.5 g/s, 2.55 g/s and 2.40 g/s, respectively. The 50 °C of ground temperature sped the debrining rate of high-viscosity oil storage in the sediment void. The oil-brine interface kept balance from the macro perspective, and the oil did not penetrate the inner brine. The oil-brine interface drops ratio of the initial diesel debrining, second diesel debrining, and petrolatum debrining process were 0.586 mm/s, 0.629 mm/s and 0.592 mm/s, respectively. The oil in the sediment voids generated movable and immobile bubbles. The petrolatum flow in the sediment void was easier than the diesel due to the low viscosity at 50 °C. The research has a certain reference value for the development of underground salt cavern oil storage.

Alfalfa Increases the Soil N Utilization Efficiency in Degraded Black Soil Farmland and Alleviates Nutrient Limitations in Soil Microbes

Alfalfa (Medicago sativa L.) can fix N naturally within soils, which makes alfalfa cultivation useful for enhancing soil fertility while minimizing environmental impacts from pesticides, fertilizers, and soil pollution. To assess the influence of alfalfa cropping on degraded black soil, we determined the nutrient stoichiometry of the soil and soil microbial biomass under four corn cultivation systems at the Harbin Corn Demonstration Base (Heilongjiang, China), which is located in Wujia (126°23′ E, 45°31′ N), Shuangcheng district, Harbin, Heilongjiang Province. The cultivation systems included continuous corn cultivation for more than 30 years (CK), 2 years of alfalfa–corn rotation (AC), three years of alfalfa cropping (TA), and four years of alfalfa cropping (FA). Overall, AC, TA, and FA treatment increased the soil pH, reduced the soil salinity, and increased the organic matter content of the 0–15 cm soil layer. TA and FA presented soil nutrient levels comparable to those of degraded cornfields that were fertilized annually. The TA and FA treatments increased the soil available N:P, soil N:P, and soil C:P ratios. Moreover, TA significantly increased the soil microbial biomass P (SMBP) in the 0–15 cm (surface) soil layer and reduced the soil microbial biomass C (SMBC):SMBP ratio. AC, TA, and FA increased the storage and mineralization rates of soil N and alleviated the microbial P limitations in degraded black soil farmland. Compared with FA, TA resulted in greater improvements in the quality of degraded black soil farmland. The ability of alfalfa to enhance soil fertility makes an important component of sustainable agricultural practices aimed at rehabilitating degraded soils.

Urban trees left high and dry – Modelling urban trees´ water supply and evapotranspiration under drought

Abstract Long-lasting extreme weather conditions are expected to occur more frequently in the future owing to climate change, as demonstrated by the recent heat waves. In particular, the decrease in precipitation during the summer months had a significant impact on urban tree water availability. Therefore, it is imperative to develop methodologies for determining the available water supply and evaporation rates for urban trees. We mapped data from 49 urban small-leaved linden trees with varying characteristics including groundwater levels, shading situations, tree pit sizes, pavement materials, and sealing ratios. By combining these data with an adapted Penman-Monteith method to calculate evapotranspiration, we simulated the soil water storage and evapotranspiration rates of these trees during the very dry year of 2018 as an example. Model validations were performed using lysimeter and sap-flow studies on Tilia cordata trees in 2022.
During the growing season, most trees experienced water stress on > 85% of the days because of weak precipitation events that failed to refill soil water storage. In contrast, trees with additional water supply through capillary rise reached water stress approximately 45 d later. The model results suggest that many trees will require additional water supply during predicted droughts in the future, which could have significant implications for urban forestry management. This model approach can be used to test and refine future water supply management strategies, making it a useful planning tool for improving the water efficiency of trees in urban areas and blue-green infrastructure.

Tailoring Pseudo-Graphitic Domain by Molybdenum Modification to Boost Sodium Storage Capacity and Durability for Hard Carbon.

Hard carbon (HC) stands out as the most prospective anode for sodium-ion batteries (SIBs) with significant potential for commercial applications. However, some long-standing and intractable obstacles, like low first coulombic efficiency (ICE), poor rate capability, storage capacity, and cycling stability, have severely hindered the conversion process from laboratory to commercialization. The above-mentioned issues are closely related to Na+ transfer kinetics, surface chemistry, and internal pseudo-graphitic carbon content. Herein, constructing molybdenum-modified hard carbon solid spheres (Mo2C/HC-5.0), both the ion transfer kinetics, surface chemistry, and internal pseudo-graphitic carbon content are comprehensively improved. Specifically, Mo2C/HC-5.0 with higher pseudo-graphitic carbon content provides a large number of active sites and a more stable layer structure, resulting in improved sodium storage capacity, rate performance, and cycling stability. Moreover, the lower defect density and specific surface area of Mo2C/HC-5.0 further enhance ICE and sodium storage capacity. Consequently, the Mo2C/HC-5.0 anode achieves a high capacity of 410.7mA h g-1 and an ICE of 83.9% at 50mA g-1. Furthermore, the material exhibits exceptional rate capability and cycling stability, maintaining a capacity of 202.8mA h g-1 at 2 A g-1 and 214.9mA h g-1 after 800 cycles at 1 A g-1.

Levy Sooty Tern Optimization Algorithm Builds DNA Storage Coding Sets for Random Access.

DNA molecules, as a storage medium, possess unique advantages. Not only does DNA storage exhibit significantly higher storage density compared to electromagnetic storage media, but it also features low energy consumption and extremely long storage times. However, the integration of DNA storage into daily life remains distant due to challenges such as low storage density, high latency, and inevitable errors during the storage process. Therefore, this paper proposes constructing a DNA storage coding set based on the Levy Sooty Tern Optimization Algorithm (LSTOA) to achieve an efficient random-access DNA storage system. Firstly, addressing the slow iteration speed and susceptibility to local optima of the Sooty Tern Optimization Algorithm (STOA), this paper introduces Levy flight operations and propose the LSTOA. Secondly, utilizing the LSTOA, this paper constructs a DNA storage encoding set to facilitate random access while meeting combinatorial constraints. To demonstrate the coding performance of the LSTOA, this paper consists of analyses on 13 benchmark test functions, showcasing its superior performance. Furthermore, under the same combinatorial constraints, the LSTOA constructs larger DNA storage coding sets, effectively reducing the read-write latency and error rate of DNA storage.

Modifying the performance kinetics in the shell-and-multi tube latent heat storage system via dedicated finned tubes for building applications

Phase change materials (PCMs) offer significant potential for building energy management, but are limited by poor heat transfer rates. This study investigates charging/discharging performance optimization of a shell-and-multi-tube heat storage system using high-enthalpy PCM (RT70HC) with differentiated fin configurations. The key novelty of the work lies in its thorough examination of geometric mutations within this system, specifically targeting building energy applications. A validated numerical model simulated charging and discharging processes, comparing finned and plain tube designs. Key performance metrics analyzed here include melting times, heat storage rates, phase transition velocities, and temperature profiles. Results reveal the finned tube design enables a 268 % higher heat storage rate (1421 W vs 387 W) and 74.5 % faster melting time (196 min vs 770 min) compared to the plain tube. Detailed analysis of the 10-h charging process exposes intricate thermal stratification patterns. The inclusion of dedicated discharging finned tubes significantly enhances heat distribution. During the 20-h discharge, heat transfer rates decrease from 2000 W to 100 W, providing crucial insights into solidification dynamics. These quantified findings highlight the potential of optimized finned tube arrays to substantially improve thermal performance of shell-and-multi-tube heat storage systems for building energy applications.