Increase In Capacity Research Articles

Unveiling Intercalation Chemistry via Interference-Free Characterization Toward Advanced Aqueous Zinc/Vanadium Pentoxide Batteries.

Aqueous Zn/V2O5 batteries are featured for high safety, low cost, and environmental compatibility. However, complex electrode components in real batteries impede the fundamental understanding of phase transition processes and intercalation chemistry. Here, model batteries based on V2O5 film electrodes which show similar electrochemical behaviors as the real ones are built. Advanced surface science characterizations of the film electrodes allow to identify intercalation trajectories of Zn2+, H2O, and H+ during V2O5 phase transition processes. Protons serve as the vanguard of intercalated species, facilitating the subsequent intercalation of Zn2+ and H2O. The increase of capacity in the activation process is mainly due to the transition from V2O5 to more active V2O5·nH2O structure caused by the partial irreversible deintercalation of H2O rather than the increase of active sites induced by the grain refinement of electrode materials. Eventually, accumulation of Zn species within the oxide electrode results in the formation of inactive (Zn3(OH)2V2O7·2H2O) structure. The established intercalation chemistry helps to design high-performance electrode materials.

Multimodal integrated and broadband light-driven antibacterial cellulose fabric based on π-π coupling enhanced intermolecular FRET

Fabrication of antimicrobial photodynamic therapy (aPDT) materials based on organic photosensitizers has garnered considerable attention within functional textiles. However, the UV- or narrow-band absorption range of the photosensitizers results in poor photon utilization of the fabrics, limiting the photodynamic efficiency and wasting solar energy. In this study, a broadband light-driven antibacterial cellulose fabric (CF-ZnPc/NAD) was developed by loading carboxyl-modified zinc(II) phthalocyanine photosensitizer (CAZnPc) and cationic 1,8-naphthalimide fluorescent molecule (NAD) on the fabric via covalent binding and electrostatic adsorption assembly, facilitating the intermolecular π-π coupling and fluorescence resonance energy transfer (FRET) process. There is a 2.54-fold increase in photo-induced ROS generation capacity of CF-ZnPc/NAD via the FRET process compared to that of CF-ZnPc, and it also exhibited a strong photothermal effect (PTT), wherein the temperature of the fabric increased from 24.5 to 53.5 °C within 80 s of illumination (λ > 400 nm, 75 mW/cm2). CF-ZnPc/NAD exhibited strong light-harvesting capacity and a combination of aPDT and PTT, achieving excellent antibacterial performance against Staphylococcus aureus (Gram-positive, S. aureus) and Escherichia coli (Gram-negative, E.coli) with 99.99 % bacterial reduction under 90 min of illumination (λ > 400 nm, 10 ± 1 mW/cm2). This study demonstrates a novel and facile strategy for successfully fabricating high-performance antibacterial cellulose fabrics with potential biomedical prospects.

Influence of Thermal Treatment and Granulometry on Physicochemical, Techno-Functional and Nutritional Properties of Lentil Flours.

Legume flours are an increasingly popular food ingredient. Thermal treatments applied prior to milling legumes and granulometry can modify flour properties, altering sensory, digestibility and functional attributes. Raw and treated (soaked and cooked) lentil flours of different granulometry were produced. The applied treatment resulted in an increase in fiber content (25.4 vs. 27.6% for raw and treated lentil flour, respectively) and water absorption capacity. It also led to a decrease in ash content (3.3 vs. 1.8% for raw and treated, respectively) and a darker flour. Treated lentil flour was mainly composed of fractions of high granulometry, which could be beneficial for products where a lower glycemic index is sought, as they demonstrated higher fiber and lower carbohydrate content than the finer fractions. Treated flour may be used as an ingredient in the development of raw products, including beverages and desserts, due to its reduced anti-nutritional compounds' content and enhanced organoleptic aspects. The obtained results allow an in-depth characterization of raw and treated lentils flour with different particle sizes to consider a formal and complete standardization of these flours and for understanding their utility and specific food applications.

Thermal-Mechanical Coupling Performance of Heat-Resistant, High-Strength and Printable Al-Si Alloy Antisymmetric Lattice Structure.

The unsatisfactory mechanical performance at high temperatures limits the broad application of 3D-printed aluminum alloy structures in extreme environments. This study investigates the mechanical behavior of 4 different lattice cell structures in high-temperature environments using AlSi12Fe2.5Ni3Mn4, a newly developed, heat-resistant, high-strength, and printable alloy. A novel Antisymmetric anti-Buckling Lattice Cell (ASLC-B) based on a unique rotation reflection multistage design is developed. Micro-CT (Computed Tomography)and SEM (Scanning Electron Microscope) analyses revealed a smooth surface and dense interior with an average porosity of less than 0.454%. Quasi-static compression tests at 25, 100, and 200°C showed that ASLC-B outperformed the other 3 lattice types in load-bearing capacity, energy absorption, and heat transfer efficiency. Specifically, the ASLC-B demonstrated a 51.56% and 44.14% increase in compression load-bearing capacity at 100 and 200°C compared to ASLC-B(AlSi10Mg), highlighting its excellent high-temperature mechanical properties. A numerical model based on the Johnson-Cook constitutive relationship revealed the damage failure mechanisms, showing ASLC-B's effectiveness in preventing buckling, enhancing load-transfer efficiency, and reducing stress concentrations. This study emphasizes the importance of improving energy absorption and mechanical performance for structural optimization in extreme conditions. The ASLC-B design offers significant advancements in maintaining structural integrity and performance under high temperatures.

The performance of waste glass aggregate concrete GFRP-steel double-skin tubular columns under axial compression: Experimental study

In an attempt to alleviate the problem of growing waste glass and fully utilize the excellent material properties of fiber-reinforced polymer (FRP), a novel composite structure, waste glass aggregate concrete glass fiber reinforced polymer (GFRP)-steel double-skin tubular column (WGAC-DSTC), was proposed based on the FRP-concrete-steel double-skin tubular column (DSTC). In the present research, eight WGAC-DSTCs and four waste glass aggregate concrete-filled GFRP tubular columns (WGAC-CFFTs) were investigated to explore their mechanical performance under axial compression. Effects of diverse replacement ratio of waste glass aggregate, GFRP tube thickness, and hollow ratio of column on the mechanical performance of twelve columns were investigated. Meanwhile, this research analyzed and discussed the failure characteristics of columns, load-displacement relationship, ductility coefficient, stiffness coefficient, parameter analysis, ultimate bearing capacity, load-strain relationship and constraint factor. Besides, predicted formulae for estimating the ultimate bearing capacity of WGAC-CFFTs and WGAC-DSTCs were proposed. The research results indicated that (1) Failure mode of the WGAC-DSTCs displayed axial compression failure or shear failure and failure mode of WGAC-CFFTs exhibited mainly axial compression failure; (2) WGAC-DSTCs with 10 % replacement ratio of waste glass aggregate and hollow ratio of 0.4 indicated an increase in the ultimate bearing capacity by 17.24 % and 45.78 %, respectively, as the GFRP tube thickness increased from 1.5 mm to 2 mm and 3 mm. As the column's hollow ratio enhanced from 0.27 to 0.68, the column's ultimate bearing capacity significantly decreased by 7.08 %-60.55 %. The ultimate bearing capacity of WGAC-CFFTs showed a trend of first increasing by 8.33 %-9.41 % but then decreasing by 1.52 % when the replacement ratio of waste glass aggregate rose from 0 % to 30 %; (3) WGAC could replace natural aggregate concrete in traditional DSTC and the bearing capacity could be guaranteed. Besides, it's recommended to utilize 20 % replacement ratio of waste glass aggregate for the WGAC-DSTC whose ultimate bearing capacity enhanced by 15.17 % and possessing optimal mechanical performance; (4) The results calculated utilizing predicted formulae matched well with results of experiment. The application of waste glass aggregate concrete in DSTC can contribute to economic growth and environmental protection and meet the concept of sustainable development.

Enhanced impact resistance of RC beams using various types of high-performance fiber-reinforced cementitious composites

This study investigates the impact resistance of reinforced concrete (RC) beams using various types of high-performance fiber-reinforced cementitious composites (HPFRCCs). A total of ten large-sized RC beams were fabricated and tested under static and impact loading conditions. Four different types of HPFRCCs with 2% by volume of steel, polyvinyl alcohol (PVA), and polyethylene (PE) fibers were considered. Ultra-high-performance fiber-reinforced concrete (UHPFRC) based on steel fibers demonstrated superior compressive and tensile strengths, while high-performance strain-hardening cementitious composite (HP-SHCC) based on PE fibers exhibited the highest strain and energy absorption capacities. The steel-bar reinforced (R-) UHPFRC and HP-SHCC beams showed superior flexural load capacity compared to reinforced normal strength concrete (R-NSC) beams. The highest ductility of 8.02 was found in the R-HP-SHCC beam, almost 5 times higher than that of the R-NSC beam. By drop hammer impact with a kinetic energy of 30 kJ, the R-UHPFRC beam completely failed due to its higher reaction load and lower structural ductility, while other RC beams made of NSC and HPFRCCs withstood the identical impact load. The R-HP-SHCC beam exhibited the best impact resistance, with a 29.1% lower maximum deflection compared to the R-NSC beam, and the largest residual load capacity after the impact damages. The R-HP-SHCC beam, despite being damaged, showed no reduction in flexural stiffness, yet it demonstrated an impressive 5.4% increase in load capacity compared to the undamaged beam.

Reduced artifacts in dynamic electrochemical impedance spectroscopy applied to battery degradation analysis

Lithium-ion batteries (LIBs) degradation can be classified into capacity reduction and increase of the internal resistance. Accurate estimation of degradation is important to determine the economic value and the remaining useful life of the battery. This paper adopts dynamic electrochemical impedance spectroscopy (EIS) to evaluate degradation while charging the battery, without requiring additional time for the analysis. A new method is proposed to remove the artifacts arising from the time-variance of the system during the measurement. The validity of the method is confirmed by comparing it with the results obtained by static EIS measurements at equilibrium. The spectra are fitted to an equivalent circuit containing three resistances (R0, R1, R2). The method is applied to data obtained before and after aging cycles performed at 1.4C charge and 2.0C discharge rates, at 25 °C, 10 °C and −5 °C. The resistance of the films (R1), which is obtained from the semicircle at high frequencies in the EIS spectrum, has proved to be the key indicator of aging, and linearly depends on the SoC. The increase of R1 dominates among all the resistances, particularly at higher temperatures. Dynamic EIS is considered a powerful tool to diagnose LIBs in practical applications.

Influence of metal ion doping for the electrochemical performance of NiCo layered double hydroxide nanostructures

Layered double hydroxide (LDH) is considered to be a potential energy storage material due to its high theoretical specific capacitance and microstructure. However, poor conductivity restricts their application and development in energy storage devices. Considering metal cations doping as an effective way to improve conductivity of semiconductors, metal cations doping can also be used to improve the conductivity of LDH. In the study, metal ions with different valence states are selected and doped into the NiCo LDH nanostructures. Indeed, metal cations doping can improve the conductivity of NiCo LDH, which can be confirmed by the results of EIS analysis. But the corresponding changes in electrode capacity are different. Compared with the Ag+ and Zn2+, Al3+ ion doped in NiCo LDH can achieve significant improvement of capacity. The capacity can reach 2130 F/g at a current density of 2 A/g when the doping concentration of Al3+ is 0.02, which has 48 % improvement compared to the original NiCo LDH (1435 F/g). The improvement of conductivity dose not determine the increase of capacity, the type and valence states of elements are also key factors affecting material capacity. Therefore, this study provides an idea for the subsequent doping of metal cations in LDH materials.

Optimizing the photovoltaic-assisted electric bus network with rooftop energy supply

As a clean and renewable resource, solar energy has demonstrated its potential to alleviate the energy vulnerability and grid strain for electric bus systems. In this study, we investigate the optimal design of an electric bus network in which rooftop solar panels are equipped to provide en-route photovoltaic assistance. A continuous-based model is proposed to optimize critical network design variables, including time-varying headway, stop spacing, and deployment of depot chargers. Introducing rooftop solar photovoltaics can significantly reduce range anxiety for electric buses. Compared with conventional electric bus systems, 4.2%–7.8 % daily in-operation time can be extended, while at most 5.7 % fleet size can also be saved per day. The proposed system demonstrates much more advantages in regions where hourly solar irradiance exceeds 1000 W/m2. Sensitivity tests indicate that (1) with a 10 % improvement in energy conversion efficiency, 1.2 % daily fleet size and 7.5 % depot chargers can be reduced; (2) every 50-kWh increase in bus battery capacity would bring a 1.8 % increment in system cost. Increasing the installation area of solar panels can help reduce battery capacity and lower the system cost. A real-world-based case in Panjin City, China is further designed to validate the application of the proposed system.

Predicting Sodium-Ion Battery Performance through Surface Chemistry Analysis and Textural Properties of Functionalized Hard Carbons Using AI.

Traditionally, the performance of sodium-ion batteries has been predicted based on a single characteristic of the electrodes and its relationship to specific capacity increase. However, recent studies have shown that this hypothesis is incorrect because their performance depends on multiple physical and chemical variables. Due to the above, the present communication shows machine learning as an innovative strategy to predict the performance of functionalized hard carbon anodes prepared from grapefruit peels. In this sense, a three-layer feed-forward Artificial Neural Network (ANN) was designed. The inputs used to feed the ANN were the physicochemical characteristics of the materials, which consisted of mercury intrusion porosimetry data (SHg and average pore), elemental analysis (C, H, N, S), ID/IG ratio obtained from RAMAN studies, and X-ray photoemission spectroscopy data of the C1s, N1s, and O1s regions. In addition, two more inputs were added: the cycle number and the applied C-rate. The ANN architecture consisted of a first hidden layer with a sigmoid transfer function and a second layer with a log-sigmoid transfer function. Finally, a sigmoid transfer function was used in the output layer. Each layer had 10 neurons. The training algorithm used was Bayesian regularization. The results show that the proposed ANN correctly predicts (R2 > 0.99) the performance of all materials. The proposed strategy provides critical insights into the variables that must be controlled during material synthesis to optimize the process and accelerate progress in developing tailored materials.

Behaviour Analysis of Beam-Type Timber and Timber-Concrete Composite Panels

This study addresses the enhancement of material efficiency and reduction in brittleness in timber-to-concrete adhesive connections for beam-type timber and timber-concrete composite panels. The research explores the potential benefits of adding longitudinal timber ribs to cross-laminated timber (CLT) beam-type panels. Three groups of flexure-tested specimens were analysed as follows: (1) timber panels (1400 mm × 400 mm) with two 100 mm thick CLT panels and two 60 mm thick CLT panels reinforced with 150 × 80 mm timber ribs; (2) eight specimens (600 mm × 100 mm × 150 mm) with CLT members (600 mm × 100 mm × 100 mm) connected to a 50 mm concrete layer using granite chips and Sikadur-31 (AB) epoxy adhesive; (3) six CLT panels (1400 mm × 400 mm × 50 mm) bonded to a 50 mm concrete layer, with two panels containing polypropylene microfibres and two panels incorporating polyethene dowels for mechanical connection. Specimens were subjected to three-point bending tests and analysed using the transformed section method, γ-method, and finite element method with ANSYS 2023R2 software. Results indicated a 53% increase in load-carrying capacity for ribbed CLT panels with no additional material consumption, a 24.8–41.1% increase for CLT panels strengthened with a concrete layer, and improved ductility and prevention of disintegration in timber-concrete composites with polypropylene microfibres.

Flexural mechanical properties of H-shaped steel-bamboo scrimber composite beams

To improve the torsional buckling resistance and enhance the load-bearing capacity and ductility of H-shaped steel beams with carbon reduction materials, the concept of combining H-shaped steel with bamboo scrimber has been proposed, in which the bamboo scrimber, an eco-friendly, lightweight, and high-strength material, promises significant structural benefits. Five full-scale specimens were designed and tested, including one H-shaped steel, two bamboo scrimber beams, and two composite beams. Additionally, further simulation tests were conducted using the verified finite element model (FEM). The experimental results revealed a remarkable increase in the ultimate bearing capacity of the composite beams by 96.5 % compared to bamboo scrimber-only beams and 72.7 % compared to steel-only beams. Meanwhile, distinct from the brittle fracture characteristics of the bamboo scrimber beams, which include instantaneous crack propagation and interlaminar cracking, the composite beams exhibited localized vertical cracks within the beam's tensile zone, effectively avoiding the torsional buckling issue of the H-shaped steel beam. The results further demonstrated that increasing the cross-sectional size of the composite beams can significantly enhance their flexural stiffness (up to 669 %), and reduce the deflection at the ultimate flexural moment. When the area of the bamboo scrimber in the cross-section was reduced with an unchanged steel profile, the initial stiffness dropped to 79 % without incurring any structural instability. Furthermore, by integrating the experimental and simulation results, a fiber element model for this composite beam structure is proposed to predict the maximum flexural moment value in the ultimate state. A corresponding calculation program was developed, and it is found that the calculated predicted ultimate flexural moment values exhibited negligible deviation from both experimental and FEM results, with AV of 1.0001, AAE of 2.21 %, and COV of 3.28 %.

Adsorption and desorption of parachlormetaxylenol by aged microplastics and molecular mechanism

The addition of active ingredients such as antibacterial agent and non-active ingredients such as plastic microspheres (MPs) in personal care products (PCPs) are the common pollutants in the aquatic environment, and their coexistence poses potential threat to the aquatic ecosystem. As a substitute for the traditional antibacterial ingredients triclosan and triclocarban, the usage of parachlormetaxylenol (PCMX) is on the rise and is widely used in PCPs. In this study, the adsorption and desorption behaviors of PCMX were investigated with two typical MPs, polyvinyl chloride (PVC) and polyethylene (PE), and the effects of different aging modes and molecular mechanisms were explored through batch experiments and density functional theory calculation. Both laboratory aging and field aging resulted in surface wrinkles of MPs, along with an increased proportion of oxygen-containing functional groups (CO, -OH). At the same aging time, the degree of laboratory aging was stronger than that of field aging, and the aging degree of PVC was greater that of PE. The aging process enhanced the adsorption capacity of MPs for PCMX. The equilibrium adsorption capacity of PVC increased from 3.713 mg/g (virgin) to 3.823 mg/g (field aging) and 3.969 mg/g (laboratory aging), while that of PE increased from 3.509 mg/g to 3.879 mg/g and 4.109 mg/g, respectively. Meanwhile, aging also resulted in an increase in the desorption capacity of PCMX from PVC and PE. Oxygen-containing functional groups in aged MPs could serve as adsorption sites for PCMX and improved the electrostatic adsorption capacity. Oxygen-containing groups generated on the surface of aged MPs formed hydrogen bonding with the phenolic hydroxyl groups of PCMX, which became the main driving force for adsorption. Our results reveal the potential impact and mechanism of aging on the adsorption of PCMX by MPs, which provides new insights for the interaction mechanism between environmental MPs and associated contaminants.

Polystyrene infused with functionalized reduced graphene oxide as a reusable oil sorbent

Adsorption has been reported to be optimal among oil spill cleanup methods due to its simplicity, low capital and operational cost, high removal efficiency and environmental friendliness. However, its continuous usage has been linked to generation of enormous waste, after oil spill cleanup, to which use of reusable oil sorbents has been proposed as a possible solution. Synthetic organic oil sorbents have high mechanical properties compared to other categories of oil sorbents, but they suffer low adsorptive capacities. To address this problem, among other nanoparticles, rGO have been infused in polymeric materials to produce composite oil sorbents characterized with high adsorptive capacities. In this research, surface modified rGO was infused in waste expanded polystyrene, to produce electrospun PS/FrGO composite sorbents by solution blending and electrospinning method. Adsorptive capacities of produced composites were evaluated in four oil samples. Functionalization of rGO was found to cause removal of residual oxygen containing functional groups such as hydroxyl (–OH), and resulted in more hydrophobic surface. Infusion of FrGO, in waste expanded polystyrene resulted into composites with increased surface area, from 71.50 m2/g for pure PS20 to 353.45 m2/g, 429.18 m2/g, 456.14 m2/g for PS20 infused with 1, 2 and 4wt% of FrGO. Increase in oil sorption capacities of the composite, observed in four oil samples corresponds to improved surface area. Produced composites show good recyclability in the four oil samples, at least up to the third sorption cycle.Graphical

Performance analysis of an Active Magnetic Regenerative system using Al2O3 nanofluids

This study investigates the utilization of Al2O3 nanofluids in an Active Magnetic Regenerative (AMR) system, focusing on varying nanoparticle concentrations from 0.01 to 1.0%. Numerical modelling is used to analyze the effects of nanoparticle incorporation on system efficiency and cooling performance. Al2O3 nanoparticles are found to significantly increase the thermal conductivity, density, and viscosity of the base fluid while reducing specific heat capacity. Comparative analysis reveals that Al2O3 nanofluids outperform pure water in terms of cooling performance, achieving a lower final temperature and a higher temperature span after 60 min of operation. Moreover, the study highlights that cooling capacity and pumping work increase with higher nanoparticle concentrations, with a notable improvement of 64.95% in cooling capacity and 39.31% in pumping work for the 1.0% Al2O3 nanofluid compared to water. The Coefficient of Performance (COP) of the AMR system peaks at an optimal nanoparticle concentration of 0.2%, reaching 3.88, before declining due to increased pumping power requirements.

Experimental study and performance evaluation of R744 thermal management systems with enhanced parallel cooling for electric vehicles

As worldwide environmental concerns grow, R744 (CO2) has become one of the preferred refrigerants in electric vehicle (EV) thermal management system due to its environmentally friendly characteristics. This study presents the development and evaluation of an Enhanced Parallel Cooling (EPC) system, a novel advancement designed to optimize the performance of R744 thermal management systems in EVs. A series of experiments are carried out to investigate the effects of key operating variables such as the coolant flow rate, and air velocity on the system efficiency. Meanwhile, Response Surface Methodology (RSM) is employed to determine the optimal control contour map under various environmental conditions. The maximum cooling capacity of the EPC system in supercharging mode is experimentally evaluated. Furthermore, a comparative analysis of driving range improvement under the Urban Dynamometer Driving Schedule (UDDS) and the Highway Fuel Economy Test (HWFET) cycles is carried out. With the help of the Series Cooling Unit (SCU) in the EPC system, the maximum cooling capacity increases by 27.8 % to 9.89 kW, and the driving range increases by up to 14.6 km. The findings underscore the potential of the innovative R744 thermal management system architecture to improve operational efficiency and extend the driving range of EVs.

Multi-Load Topology Optimization Design for the Structural Safety Maintenance of Low- and Intermediate-Level Radioactive Waste Packaging Containers in the Case of a Collision.

This paper presents an optimized design approach using nonlinear dynamic analysis and finite element methods to ensure the structural integrity of square-shaped containers made from ductile cast iron for intermediate- and low-level radioactive waste packaging. Ductile cast iron, with its spherical graphite structure, effectively distributes stress throughout the material, leading to a storage capacity increase of approximately 18%. Considering the critical need for containers that maintain integrity under extreme conditions like earthquakes, the design focuses on mitigating stress concentrations at the corners of square structures. Nonlinear dynamic analyses were conducted in five drop directions: three specified by ASTM-D5276 standards and two additional directions to account for different load patterns. Fractures were observed in four out of the five scenarios. For each direction where fractures occurred, equivalent loads causing similar displacement fields were applied to linear static models, which were then used for multi-load topology optimization. Three optimized models were derived, each increasing the volume by 1.4% to 1.6% compared to the original model, and the design that best met the structural integrity requirements during drop scenarios was selected. To further enhance the optimization process, weights were assigned to different load conditions based on numerical analysis results, balancing the impact of maximum stress, average stress, and plastic deformation energy. The final model, with its increased storage capacity and enhanced structural integrity, offers a practical solution for radioactive waste management, overcoming limitations in previous designs by effectively addressing complex load conditions.

Efficient microwave induction to modify surface for high-rate lithium/fluorinated carbon battery with ultra-high power density

The practical application of high-rate lithium/fluorinated carbon (Li/CFx) primary batteries faces challenge of relatively slow electrode reaction kinetics limited by inert C-F bond and strong polarity. Herein, an effective microwave-induction strategy was developed to regulate C-F bond for 80C high-rate Li/CFx battery with suppressed polarization. The as-mentioned microwave method was carried out in the alcohol-based solvent for uniformly modify CFx, including precise defluorination, C-F bond regulation, surface functional groups and carbon quantum dots. Precise defluorination contains the conversion of C-F bond to semi-ionic C-F bond while preserving C-F2 and C-F3. During the process of C-F bond regulation, hydroxyl groups is grafted onto the surface of CFx to increase the wettability and electronegativity of the electrode. Compared with raw CFx, the Li/CFx batteries using microwave-modified CFx achieved high discharge rate of 80C possessing a high power density of 134.091 kW/kg. In addition, the optimal Li/CFx battery possesses a large specific capacity increase ratio of 142.6 % at 50C. This microwave-induction approach for modifying CFx in ethanol-based solvent provides a facile and effective pathway to design high-rate Li/CFx battery.

Thermal Behaviour of Hydrofugated Plaster Block Masonry with Variation of Coating Thickness

The objective of this research is to analyze the influence of ceramic coating, simulating the external side, and plaster with different thicknesses, simulating the internal side of a prototype of solid water-repellent gypsum block masonry, aiming to improve the thermal performance mainly in the settlement joints of the block. For this purpose, two specific test methods were used: thermal camera and infrared thermography. The temperature differences between the internal and external faces were analyzed by means of thermocouples connected in the middle of the prototype and the mapping of the temperature profile on the surface of the cladding. It was found that the addition of gypsum sheathing plus ceramic improves the thermal performance of the masonry system, observing that the variation of the thickness of the gypsum mortar provides a gain in thermal resistance, a reduction in thermal transmittance and an increase in thermal capacity.

Optimizing an auxetic metamaterial structure for enhanced mechanical energy absorption: Design and performance evaluation under compressive and impact loading

Auxetic metamaterials, characterized by their negative Poisson’s ratio, offer promising prospects for utilization in absorbing energy during quasi-static compressive loading as well as in applications requiring impact energy absorption. The optimization of auxetic structures’ geometrical parameters can improve their performance. This research aims to optimize the design of an auxetic structure for maximum specific energy absorption and investigate its behavior under quasi-static compressive and high-velocity impact loading. The geometrical parameters of the cross-petal auxetic structure are optimized using genetic algorithm and a neural network surrogate model. The behavior of the optimized auxetic structure is examined in quasi-static compressive loading and compared with that of the basic auxetic structure using finite element simulations. The optimized auxetic structure is then evaluated in high-velocity impact loading as the core of a sandwich panel, with two plates placed in the front and rear. Simulations of projectile impacts at velocities ranging from 100 to 250 m/s reveal the sandwich panel’s behavior. Results indicate a 69.82% increase in specific energy absorption capacity for the optimized auxetic structure as compared to the basic structure in quasi-static compressive loading. In high-velocity impact, the sandwich panel with the optimal auxetic core outperforms the one with the basic core. At velocities more than the minimum perforation velocity, the core contributes about 64%–67% of the total absorbed energy by the sandwich panel.