Maximum Capacity Research Articles

Biosorbent treatment of fluorene using activated carbon derived from the pyrolysis process of date pit wastes

Activated carbon (AC) derived from Date pits (DP) wastes was used as an eco-friendly and effective biosorbent for the removal of fluorene (FLU) from organic wastes. The maximum capacity of DP was 6.71 mg g−1, compatible with the Freundlich model. FLU adsorption's chemisorption performance on DP was involved in following a superior linear fit for the pseudo-2nd-kinetic model. The maximum adsorption capacity from the pseudo-2nd order kinetic model fitted with the experimental findings and found to be 3.73 g, 2.62, 1.13, 0.955, 0.749, 0.591, and 0.665 mg g−1 at 25, 3, 35, 4, 45, 5 and 55 °C, respectively. The negative value of the spontaneous nature of the adsorption corresponds to the exothermic nature however, + ΔS corresponds to an increase in the degree of freedom for FLU adsorption. The relatively high value of activation energy (Ea) demonstrates that the adsorption of FLU onto DP is classified as chemical adsorption, and found to be 84.8 kJ mol−1. Also, the result of XRD shows that the prepared DP was re-used four times without substantially decreasing performance. In addition, it appears that AC prepared from DP is a promising adsorbent with a low cost for removing many organic pollutants.

The Structural Behavior of Lightweight Self-Compacting Concrete Slabs Using Different Types of Reinforcement

The purpose of this study is to examine how the type of reinforcement used in self-compacting concrete (SCC) and lightweight self-compacting concrete (LWSCC) affects their structural behavior. There were three forms of reinforcement used: wire mesh, glass fiber-reinforced rebars, and regular steel rebars. To evaluate the mechanical characteristics of reinforced concrete slabs with various types of reinforcement, extensive experiments were carried out. The tensile strength, stiffness, and crack resistance of the concrete were studied in each case. The finite element program Abaqus was utilized in addition to the experimental investigations to create the numerical simulation of the test. The experimental results revealed that the reinforcement type significantly affects the structural behavior of SCC and LWSCC slabs. Conventional steel rebars provided high tensile strength and excellent crack resistance, while glass fiber-reinforced rebars contributed to enhanced flexibility and reduced overall weight of the concrete. On the other hand, the wire mesh exhibited average mechanical and structural properties. These findings emphasize the importance of selecting the appropriate reinforcement type based on specific applications and desired performance requirements. This research provides valuable guidance for architects and civil engineers in choosing optimal reinforcement for SCC and LWSCC. Furthermore, it can contribute to the advancement of techniques and potential improvements in these materials to achieve better performance and enhance sustainability in infrastructure and building construction. From the practical results, it was found that in the case of using lightweight self-compacting concrete and self-compacting concrete, it is preferable to reinforce it with ordinary reinforcement steel, as it gives the best results in terms of maximum load capacity at failure. Although the use of steel reinforcement in self-compacting concrete also gives the best results, but from the laboratory results it is possible to improve the performance of self-compacting concrete by reinforcing it with GFRP or welded wire mesh.

Wastewater treatment optimization utilizing polyvinyl alcohol cryogel immobilized microalgae for nutrient removal

This study investigated the use of polyvinyl alcohol (PVA) cryogels to immobilize microalgae for wastewater treatment. Chlorella sorokiniana was successfully entrapped in PVA cryogels via repeated freeze/thaw cycles. The nutrient removal efficiency of these cryogels was tested in a continuously stirred photobioreactor under varying conditions, both with and without the addition of an organic carbon source (sodium acetate). The presence of organic carbon significantly enhanced nutrient removal. Specifically, PVA cryogels with immobilized C. sorokiniana achieved 100% nitrogen removal and 97.2% phosphorus removal under mixotrophic conditions. Furthermore, the maximum nutrient removal capacities of the PVA cryogels were found to be 0.033 mg-N/cube·day for nitrogen and 0.0047 mg-P/cube·day for phosphorus. As the inorganic carbon (bicarbonate) concentration increased from 5 to 100 mg/L, the N/P ratio rose from 6 to 8, with a higher N/P ratio of 10 observed when nitrate nitrogen was used as the nitrogen source, compared to ammonia nitrogen, at 100 mg/L bicarbonate. This study offers an effective method for using microalgae immobilized in PVA cryogels for wastewater treatment. The findings highlight the potential for PVA cryogels to significantly improve nutrient removal efficiency, particularly in the presence of organic carbon sources, thereby enhancing bioreactor performance. High nitrogen and phosphorus removal efficiencies can help reduce eutrophication in water bodies, protect aquatic ecosystems, and enable nutrient recovery and reuse, supporting a circular economy in wastewater treatment practices.

Density Functional Investigations on 2D‐Be2C as an Anode for Alkali Metal‐Ion Batteries

ABSTRACTMetal‐ion batteries are in huge demand to cope with the increasing need for renewable energy, especially in automobiles. In this work, we apply first‐principle calculations to examine two‐dimensional beryllium carbide (2D‐Be2C) as a possible anode material for metal‐ion (Na and K) batteries. 2D‐Be2C is a semiconductor and becomes metallic by adsorbing metal ions. Negative adsorption energy indicates stable adsorption on the monolayer of Be2C. Alkali metal diffusion barrier and optimum path for minimum energy are studied within the framework of the climbing image nudged elastic band method. Here, six intermediate images are considered between the initial and final states. The lowest diffusion barriers for a single adsorbed Na and K atom are 0.016 and 0.026 eV, respectively. A maximum open circuit voltage of around 1 V is computed for K ions, whereas 0.5 V is for Na ions. Also, the maximum storage capacity of the Be2C monolayer is estimated at 1785 Ah/kg.

Identifying targetable metabolic dependencies across colorectal cancer progression

Colorectal cancer (CRC) is a multi-stage process initiated through the formation of a benign adenoma, progressing to an invasive carcinoma and finally metastatic spread. Tumour cells must adapt their metabolism to support the energetic and biosynthetic demands associated with disease progression. As such, targeting cancer cell metabolism is a promising therapeutic avenue in CRC. However, to identify tractable nodes of metabolic vulnerability specific to CRC stage, we must understand how metabolism changes during CRC development. Here, we use a unique model system – comprising human early adenoma to late adenocarcinoma. We show that adenoma cells transition to elevated glycolysis at the early stages of tumour progression but maintain oxidative metabolism. Progressed adenocarcinoma cells rely more on glutamine-derived carbon to fuel the TCA cycle, whereas glycolysis and TCA cycle activity remain tightly coupled in early adenoma cells. Adenocarcinoma cells are more flexible with respect to fuel source, enabling them to proliferate in nutrient-poor environments. Despite this plasticity, we identify asparagine (ASN) synthesis as a node of metabolic vulnerability in late-stage adenocarcinoma cells. We show that loss of asparagine synthetase (ASNS) blocks their proliferation, whereas early adenoma cells are largely resistant to ASN deprivation. Mechanistically, we show that late-stage adenocarcinoma cells are dependent on ASNS to support mTORC1 signalling and maximal glycolytic and oxidative capacity. Resistance to ASNS loss in early adenoma cells is likely due to a feedback loop, absent in late-stage cells, allowing them to sense and regulate ASN levels and supplement ASN by autophagy. Together, our study defines metabolic changes during CRC development and highlights ASN synthesis as a targetable metabolic vulnerability in later stage disease.

A Non-Weight Bearing Method for Measuring Hip Abduction Strength Overestimates Hip Abductor Muscle Fatigue During One-Leg Stance

OCCUPATIONAL APPLICATIONS Assessing workers’ strength capacities is a common practice prior to return to work following injury or illness, or assessing capabilities for strenuous jobs. Because it requires 50% or more of maximum strength capacity, hip abductor muscle strength is a strong predictor of both middle- and older-aged individuals’ ability to reliably balance on one leg and of their risk of falls. Our results suggest subjects were able to augment their hip abductor moment during unipedal weight stance via gluteus maximus activity. Weight-bearing hip abduction strength measures are important for assessing worker capacity for jobs requiring reliable unipedal balance whether during lateral loading, while walking in gusty winds, on slippery footing or resisting lateral deck movements on board ship or train. Measurements of hip abductor strength should be made in a full unipedal weight bearing posture; non-weight-bearing measurements significantly underpredicted hip abductor strength as well as endurance.

Scalable Li-Ion Battery with Metal/Metal Oxide Sulfur Cathode and Lithiated Silicon Oxide/Carbon Anode.

A Li-ion battery combines a cathode benefitting from Sn and MnO2 with high sulfur content, and a lithiated anode including fumed silica, few layer graphene (FLG) and amorphous carbon. This battery is considered a scalable version of the system based on lithium-sulfur (Li-S) conversion, since it exploits at the anode the Li-ion electrochemistry instead of Li-metal stripping/deposition. Sn and MnO2 are used as cathode additives to improve the electrochemical process, increase sulfur utilization, while mitigating the polysulfides loss typical of Li-S devices. The cathode demonstrates in half-cell a maximum capacity of ~1170 mAh gS -1, rate performance extended over 1 C, and retention of 250 cycles. The anode undergoes Li-(de)alloying with silicon, Li-(de)insertion into amorphous carbon, and Li-(de)intercalation through FLG, with capacity of 500 mAh g-1 in half-cell, completely retained over 400 cycles. The full-cells are assembled by combining a sulfur cathode with active material loading up to 3 mg cm-2 and lithiated version of the anode, achieved either using an electrochemical pathway or a chemical one. The cells deliver at C/5 initial capacity higher than 1000 mAh gS -1, retained for over ~40 % upon 400 cycles. The battery is considered a promising energy storage system for possible scaling-up in pouch or cylindrical cells.

Synthesis and Redox Activity of Polyenaminones for Sustainable Energy Storage Applications

In the search for novel polymeric molecules that could be used as electroactive materials, seven novel polyenaminones were prepared in high yields by the transaminative polymerization of resorcinol-derived bis-enaminones with m- and p-phenylenediamine and with 2,5-diaminohydroquinone. The obtained polymers show very low solubility in organic solvents and absorb UV light and visible light at wavelengths below 500 nm. All the obtained polymeric products were tested for redox activity in a Li battery setup. The 2,5-diaminohydroquinone-derived compound showed the best redox activity, with a maximum capacity of 86 mAh/g and relatively good capacity retention, thus confirming the hydroquinone group as the primary redox-active group. Other potential redox-active groups, such as resorcinol and conjugated carbonyls, showed limited activity, while variations in the phenylene groups and the substitution of phenolic groups in the resorcinol residue did not impact the electrochemical activity of the polymers. Their electrochemical properties, together with their previously established chemical recyclability, make polyenaminones promising scaffolds for the development of materials for sustainable energy storage applications.

Eco-Friendly Carbon Nanotubes Reinforced with Sodium Alginate/Polyacrylic Acid for Enhanced Adsorption of Copper Ions: Kinetics, Isotherm, and Mechanism Adsorption Studies.

This study investigates the removal efficiency of Cu2+ from wastewater using a composite hydrogel made of carbon nanotubes (CNTs), sodium alginate (SA), and polyacrylic acid (PAA) prepared by free radical polymerization. The CNTs@SA/PAA hydrogel's structure and properties were characterized using SEM, TEM, FTIR, XRD, rheology, DSC, EDS, elemental mapping analysis, and swelling. The adsorption performance for Cu2+ was tested in batch adsorption experiments, considering the pH, dosage, initial concentration, and contact time. The optimal conditions for Cu2+ removal were pH 5.0, an adsorbent dosage of 500 mg/L, and a contact time of 360 min. The adsorption followed pseudo-second order kinetics. Isotherm analyses (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Sips, Toth, and Khan) revealed that the Freundlich isotherm best described the adsorption, with a maximum capacity of 358.52 mg/g. A thermodynamic analysis indicated that physical adsorption was the main interaction, with the spontaneity of the process also demonstrated. This study highlights the high efficiency and environmental friendliness of CNT@SA/PAA composites for Cu2+ removal from wastewater, offering a promising approach for water treatment.

Multiple-amine functionalized γ–Al2O3 for post-combustion CO2 capture: Performance, mechanism, and kinetics

High-efficiency and cost-effective adsorbents are crucial to dry capture of carbon dioxide (CO2). The polyethyleneimine (PEI) was co-impregnated with tetraethylenepentamine (TEPA) on γ-alumina (Al2O3) to synthesize the adsorbent and enhance the capture process. The influence of amine loading and operating parameters on CO2 adsorption was investigated, and the process parameters were modeled. The results depict that the optimal loading is 50 % when functionalized either PEI or TEPA individually, which is 3.7 and 4.6 times higher than γ–Al2O3. The CO2 capacity of γ–Al2O3 functionalized with multiple amines (30 %PEI+20 %TEPA) is 2.65 mmol/g, due to the synergies of the two amines to increase the chance of CO2 binding to the sites. Regeneration performance illustrates that the adsorbent remains at 90.2 % of the initial capacity after seven tests. The maximal capacity of 2.70 mmol/g occurs at 70 °C. Modeling results indicate the kinetics can be evaluated by the Avrami model (R2 > 0.990) with the activation energy of 5.65 kJ/mol. The process is controlled by physical–chemical adsorption, influenced by intraparticle diffusion, as described by the deactivation model. Finally, a comparison and assessment were conducted for their techno-economic performances, and the pathway to applications was also proposed in engineering practice.

Maximum Error Insertion (MEI): A Novel Benchmarking Method for Data Hiding Algorithms

Data hiding is becoming increasingly important due to the growing threat to the privacy and security of data from intruders and hackers. This situation is accompanied by the advancement in artificial intelligence applications designed to reveal hidden data, making it difficult to choose the most appropriate hiding approach from those presented in literature. The benchmarking method serves as an important roadmap for making decisions. We propose a distinct plain benchmarking method called maximum error insertion (MEI) benchmarking. This approach intends to hide data using maximum error insertion. The MEI refers to the maximum amount of distortion that can be added to host data (such as image or audio) while still ensuring the successful retrieval of hidden data. The maximum error that can be generated by each hiding algorithm is intentionally inserted to the media file, thus giving us maximum error, maximum capacity, and maximum sensitivity to signal processing attacks. Investigation of the two hiding algorithms demonstrates their applicability and precision, and their implementation significantly enhances the reliability of results during the benchmarking stage.

Synthesis and evaluation of iron oxide nanoparticles from banana peel (Musa spp.) extract for the delivery of ciprofloxacin against resistant Escherichia coli

Background and objectiveResistance to antimicrobials is one of our most significant worldwide challenges. In Africa, around 31 % of the infections of urinary tract (UTIs) initiated by Escherichia coli (E. coli) have been observed to develop ciprofloxacin (CIP) resistance. As a result, significant efforts have been made to investigate novel and improved antibiotics. This study aimed at synthesizing iron oxide nanoparticles (IONPs) using banana peels (Musa Spp.) extract for delivery of CIP against resistant E. coli. MethodsA green synthesis method was used for the synthesis of IONPs using FeCl3.6H2O as a precursor and banana peel extract as a reducing and stabilizing agent. The physicochemical characteristics of the formed nanoparticles (NPs) were characterized using different methods. ResultsThe formation of hematite (α-Fe2O3) was confirmed with its FTIR characteristic peak at 461 cm−1, 542 cm−1, and 1131 cm−1. The size of synthesized IONPs was found to be 10.4 nm ± 1.98, 48 nm ± 0.9, and 67.3 nm ± 0.9 under XRD, SEM, and DLS measurements respectively. CIP-IONPs had almost the maximum drug loading capacity (33.3 % ± 0.67) with fast and slow drug release patterns at gastric and intestinal or blood pH respectively, and it had a promising resistant reversal with a zone of inhibition (ZOI) 22 mm ± 0.15 against resistance E. coli. ConclusionThe green synthesis of IONP using banana peel extract represents a novel and eco-friendly approach for the delivery of ciprofloxacin, with potential applications in addressing antimicrobial resistance.

Development of reinforced concrete column with replaceable plastic hinge based on metabolism concept

To update seismic performance and rapidly restore the transportation capacity of a bridge following an earthquake, this study introduces a new reinforced concrete (RC) column, termed “Metabolic RC column,” which incorporates the Design for Disassembly and Metabolism Movement concepts. The proposed column features a plastic hinge comprising a permanent hinge and replaceable plastic zones. A Mesnager hinge is employed as the permanent hinge to resist the axial loads within the column cross section. In addition, cast-in-place RC members are used in replaceable plastic zones to dissipate the seismic energy. By replacing the plastic zone with an equivalent or superior alternative while the permanent hinge continues to carry the axial forces, the updating (i.e., metabolization) of the column seismic performance can be achieved without interrupting the daily operations of the structure. The feasibility of replacing plastic hinges while maintaining the resistance to axial loads was demonstrated through plastic zone replacement tests. Cyclic loading tests indicated that the maximum lateral load of the proposed Metabolic RC Column remained unchanged before and after the plastic zone replacement. The energy dissipated also remained nearly consistent before and after the plastic zone replacement. The largest reduction in dissipated energy at each displacement amplitude was approximately 6.7 % before and after replacement. Additionally, the cyclic loading tests emphasized the importance of minimizing damage to the permanent hinge and preventing the axial stiffness reduction to ensure maximum load capacity of the column after plastic zone replacement. Further, a numerical model was developed to replicate the load-displacement relationship of the specimens. The proposed model accurately calculated the maximum load of the specimen with an average error of approximately 3 % for each displacement amplitude and the dissipated energy with an error of approximately 6 %. The numerical analysis effectively captured the changes in the secondary stiffness of the columns before and after plastic zone replacement, attributing the differences in secondary stiffness to the reduced tensile forces exerted by the permanent hinge rebar.

Investigating the Impact of Flavonoids on Aspergillus flavus: Insights into Cell Wall Damage and Biofilms.

Aspergillus flavus, a fungus known for producing aflatoxins, poses significant threats to agriculture and global health. Flavonoids, plant-derived compounds, inhibit A. flavus proliferation and mitigate aflatoxin production, although the precise molecular and physical mechanisms underlying these effects remain poorly understood. In this study, we investigated three flavonoids-apigenin, luteolin, and quercetin-applied to A. flavus NRRL 3357. We determined the following: (1) glycosylated luteolin led to a 10% reduction in maximum fungal growth capacity; (2) quercetin affected cell wall integrity by triggering extreme mycelial collapse, while apigenin and luteolin caused peeling of the outer layer of cell wall; (3) luteolin exhibited the highest antioxidant capacity in the environment compared to apigenin and quercetin; (4) osmotic stress assays did not reveal morphological defects; (5) flavonoids promoted cell adherence, a precursor for biofilm formation; and (6) RNA sequencing analysis revealed that flavonoids impact expression of putative cell wall and plasma membrane biosynthesis genes. Our findings suggest that the differential effects of quercetin, luteolin, and apigenin on membrane integrity and biofilm formation may be driven by their interactions with fungal cell walls. These insights may inform the development of novel antifungal additives or plant breeding strategies focusing on plant-derived compounds in crop protection.

Capture of Iodine in Vapor and Solution Phases by a Th-Based Metal-Organic Framework.

The efficient capture of radioactive iodine is of paramount importance due to its harmfulness. In this work, a new Th-based metal-organic framework (ECUT-Th-11) for iodine capture was reported. ECUT-Th-11 exhibited a relatively high capacity of capturing vapor iodine (2.03 g/g). Besides, the maximal adsorption capacity of iodine in a cyclohexane solution reaches 258.03 mg/g. All of the results demonstrated that ECUT-Th-11 could be a candidate material for the effective removal of waste iodine.

Sequential super-assembled nanomotor adsorbents for NIR light-Powered blood lead removal

Hemoperfusion is a common treatment for lead poisoning, where hemoperfusion adsorbents are used to remove lead ions from blood. However, traditional hemoperfusion adsorbents often suffer from limited efficiency and poor biocompatibility, reducing their effectiveness for human use. To address these limitations, we developed a novel photothermal nanomotor adsorbent through a controllable sequential super-assembly strategy. Gold nanoparticles (Au NPs) were incorporated into the nanochannels of halloysite nanotubes (HNTs), followed by modification of the outer HNT surface with polydopamine (PDA) and 2,3-dimercaptosuccinic acid (DMSA), forming Au@HNTs@PDA-DMSA. This nanomotor adsorbent leverages the photothermal properties of Au NPs to achieve self-propulsion via thermophoresis under near-infrared (NIR) light irradiation. The performance of this nanomotor was evaluated for Pb(II) removal in both aqueous solutions and human blood samples, reaching adsorption equilibrium within 20 min and a maximum capacity of 45.980 mg/g. The adsorption kinetics followed a pseudo-second-order model with a high fitting coefficient (R2 = 0.999), and the Langmuir model fit better than the Freundlich model, indicating monolayer adsorption. Notably, when driven by 808 nm NIR light at 1.0 W cm−2, the Au@HNTs@PDA-DMSA nanomotors showed a significantly enhanced adsorption capacity of 151.769 mg/g, improving blood lead removal efficiency by 1.80 times compared to non-irradiated conditions. Furthermore, the addition of sulfhydryl and carboxyl groups from DMSA provided more active sites, leading to a 9.76-fold increase in lead removal compared to passive adsorbents using HNTs. In vitro tests confirmed the excellent biocompatibility and biosafety of the nanomotor adsorbent, achieving a blood lead removal rate of 91.25 %. This advancement overcomes the limitations of traditional lead adsorbents, offering a promising solution for more effective lead detoxification in clinical and environmental settings.

The impacts of DC/AC ratio, battery dispatch, and degradation on financial evaluation of bifacial PV+BESS systems

As the price of solar modules has decreased, oversizing PV system becomes a general practice. Without proper energy management, the oversized systems could lead to over-generation waste which cause a loss in revenue. Battery energy storage system (BESS) can be integrated to the PV system for utilizing the over-consumption energy and increasing the system’s financial benefits. This paper highlights the influence of technical and financial factors on the photovoltaic (PV) and PV with BESS design. To analyze the impacts of the factors on PV systems, thirty-six system configurations with a variety of geographic locations, tariff structures, billing methods, and PV system technology are simulated using System Advisor Model (SAM) as a tool with result validation from measurements on a real oversized residential grid-tied bifacial PV+BESS system. To study the financial criteria that affect the optimal system design, we conducted the sensitivity analysis of the DC/AC ratio, battery replacement threshold, and battery size to observe the optimal system design based on three financial outputs: levelized cost of energy (LCOE), net present value (NPV), and payback period. The findings show that the optimal DC/AC ratio for residential-scale PV systems lies between 1.1 - 1.3 and can go up to 1.6 with BESS. PV+BESS systems can reduce the payback period by 20% and boost NPV by 80% compared to the PV-only systems. The sensitivity study of the battery replacement shows that the battery can be degraded until 50% of its maximum capacity for the lowest LCOE. To achieve the optimal grid-tied PV system design, each economic parameter should be evaluated together.

Analytical derivation of optimal irrigation water depth for efficient irrigation scheduling.

Optimal irrigation water depth is a crucial parameter in irrigation engineering, often referred to as root zone depth. It is typically assumed to lie between 1 and 1.5m below the ground surface, depending on the crop and soil types as well as the practitioner's skill and experience. This approach can lead to inefficient irrigation scheduling. Coupling Richards' equation with the Soil Conservation Service Curve Number (SCS-CN) concept and using the three-phase diagram of soil column widely used in geotechnical engineering, this paper suggests an analytical expression for optimal irrigation water depth providing the maximum storage capacity of a soil depending on its hydraulic/storage properties. The results for winter wheat crop in different hydrologic soil groups show that the use of the proposed concept can lead to savings of 71.79% and 57.69% of irrigation water in sandy soils (HSG-A) compared to that used in traditional irrigation considering lump-sum 1.5m and 1m optimal irrigation water depths, respectively. In the case of silty loam soils (HSG-C), these savings can assume 52.42% and 28.62%, respectively. The proposed relation can also be of great help in volumetric assessment of field capacity, moisture content, maximum water storage capacity (of different agricultural soils), and avoiding the issue of waterlogging that may arise from over-irrigation and thus is useful in efficient irrigation scheduling as well as in sustainable agricultural water management.

Coexistence of Redox‐Active Metal and Ligand Sites in Copper‐based 2D Conjugated Metal‐Organic Frameworks for Battery‐Supercapacitor hybrid systems

Two‐dimensional (2D) conjugated metal‐organic frameworks (c‐MOFs) are promising materials for supercapacitor (SC) electrodes due to their high electrochemically accessible surface area coupled with superior electrical conductivity compared to traditional MOFs. Here, porous and non‐porous HHB‐Cu (HHB=hexahydroxybenzene), derived through surfactant‐assisted synthesis, are studied as representative 2D c‐MOF models, showing different reversible redox reactions with Na+ and Li+ in aqueous and organic electrolytes, respectively. We deployed these redox activities to design negative electrodes for hybrid SCs (HSCs), combining the battery‐like property of HHB‐Cu as negative electrode and the high capacitance and robust cyclic stability of activated carbon (AC) as positive electrode. In organic electrolyte, porous HHB‐Cu‐based HSC achieves a maximum cell specific capacity (Cs) of 22.1 mAhg‐1 at 0.1 Ag‐1, specific energy (Es) of 15.55 Whkg‐1 at specific power (Ps) of 70.49 Wkg‐1, and 77% cyclic stability after 3000 gravimetric charge‐discharge (GCD) cycles at 1 Ag‐1 (calculated on the mass of both electrode materials). In the aqueous electrolyte, porous HHB‐Cu‐based HSC displays a Cs of 13.9 mAhg‐1 at 0.1 Ag‐1, Es of 6.13 Whkg‐1 at 44.05 Wkg‐1, and 72.3% Cs retention after 3000 GCD cycles. The non‐porous sample shows lower Es performance but better rate capability compared to the porous one.

Wall sandwich panels with steel facings and PUR foam core under transverse loading: Experimental testing and numerical model calibration

Light weight panels are largely used for the envelope (wall assembly, roofing system) of different kind of buildings. Under extreme loading conditions, like external explosions, the walls may suffer extensive damage, under either positive or negative pressures. The study presented in the paper describes the results obtained on wall sandwich panels tested for transverse loading until complete failure. The panels are arranged as single span systems supported on side rails and loaded at the mid-span. After a quasi-linear response, the maximum bending capacity is reached. At this point, the panels have a sudden drop in capacity, associated with the rapid wrinkling of the face in compression. If the end fasteners have adequate resistance, catenary stage develops, and the ultimate capacity can be significantly higher than the peak bending capacity. Flexibility of the lateral restraints significantly influence the initiation of catenary action and the ultimate capacity of sandwich panels. Numerical models were calibrated using the structural analysis and design program SAP2000. This may allow professionals to integrate more quickly the wall models into the structural design even for extreme loading conditions.