Maximum Density Research Articles

Regulation of wood porous structure and construction of reduced graphene oxide@wood derived carbon conducting collector

With the gradual increase in the consumption of non-renewable energy sources, the development of energy storage and conversion devices has become increasingly important. Sustainable self-supporting conductive collectors have become one of the effective ways to enhance the performance of energy storage devices. In this study, the pore modulation technique was implemented on Beijing poplar and camphor pine using delignification and water extraction, and six wood-derived carbon (WC) electrodes were prepared by heat treatment using untreated material as a control. By observing the microscopic morphology, it was found that all six carbon materials retained the graded porous structure characteristic of natural wood. The carbon material prepared from water extraction treated Beijing poplar (WPC) had the best capacitive properties. The conductive reduced graphene oxide (RGO) is composited with WPC, and the constructed RGO@WPC (RWPC) conductive collector has an average conductivity as high as 15.4 S m−1, which provides a strong guarantee for fast electron transport. The specific capacitance of RWPC is as high as 2100 mF cm−2 when the current density is 1 mA cm−2. The constructed RWPC//RWPC energy storage device has a maximum energy density of 3.76 Wh kg−1 and a maximum power density of 171.3 W kg−1. In this paper, a green and efficient self-supporting conductive collector with a graded porous structure is proposed. It also broadens the high value-added utilization of wood in energy storage.

Impact of microplastics on strength parameters of clayey, Sandy, silty soil: A comparative assessment

The comparative assessment of a variety of microplastic contamination on various soil types hasn't been extensively explored in existing literature. The present study focuses on the comparative analysis of the impact of environmentally relevant concentrations of LDPE, HDPE, and PVC microplastic contamination (2 %, 4 %, and 6 %) on index properties and strength parameters of sandy, silty and clayey soil types at varying observation days 5,10,15,20,25, and 30 days. Extensive experimental investigations are carried out to understand the effect of contamination on moisture content, specific gravity, liquid limit, plastic limit, plasticity index, optimum moisture content, maximum dry density, and shear strength parameters of the respective soil type. It is observed that the depletion in Atterberg's limits is found more in the case of clayey soil as compared to silty soil because clayey soils consist of large specific surface areas leading to van der Waals force of attraction being the predominant force between particles, compared with silty soil which is affected by microplastic addition leading to decrease in net attractive forces. In the case of clayey soil maximum depletion of liquid limit up to 168 %, plastic limit up to 33 %, plasticity index (136 %), and optimum moisture content (9.04 %) is observed for PVC microplastic. The deduction in maximum dry density values is observed more for sandy soil (0.59 g/cc) followed by silty soil (0.21 g/cc) and clayey soil (0.12 g/cc). The maximum depletion of moisture content(delta-8 %), shear strength (delta-0.89 kg/cm2), and maximum dry density (delta-0.44 g/cc) is observed in the case of sandy soil for PVC and LDPE microplastic contamination. Significant depletion in optimum moisture content is observed in the case of clayey soil (9.57 %) compared to sandy (5.62 %) and silty soil (5.3 %). An increase in cohesion is observed for sandy soil (0.09 kg/cm2) and a decrease for clayey (0.19 kg/cm2) and silty soil (0.19 kg/cm2). The angle of internal friction is reduced in the case of clayey soil (∆-14.380) followed by silty soil (∆-11.230) and sandy soil (∆-11.020). For silty soil maximum depletion of specific gravity(delta-1.06) and cohesion (0.192 kg/cm2) is observed for LDPE and HDPE microplastic. The sandy soil type is most affected due to microplastic contamination irrespective of the type of microplastic contamination followed by clayey soil and the silty soil type is least affected. The maximum overall shear strength is reduced due to microplastic contamination in all the soil types.

DEVELOPMENT OF DRY MIX MORTARS FOR FLOOR ELEMENTS

Dry mix mortars are widely used in construction projects for the implementation of construction works in new construction, reconstruction, and repair. The improvement of properties of dry mix mortars for the installation of floor screeds is relevant. The purpose of such mortars is to equalize the differences in the thickness of the floor surface, to create an intermediate layer characterized by the necessary strength, durability, and even surface with the possibility of decoration with various types of flooring. A step-by-step design of the composition of dry mix mortar for the installation of floor screeds was carried out. The ratio of fine aggregates and limestone filler was optimized according to the maximum packing density criterion, the required amount of plasticizer was selected according to the consistency index of the fresh mortar, and the minimum amount of Portland cement was selected to ensure the required strength.

Enabling extreme low-temperature proton pseudocapacitor with tailored pseudocapacitive electrodes and antifreezing electrolytes engineering

A critical current challenge in the development of proton pseudocapacitors is developing antifreezing electrolytes and high-performance proton storage materials in extreme environments. Here, we design an antifreezing proton pseudocapacitor using a high-concentration phosphoric acid electrolyte and pseudocapacitive electrode materials, which delivers an outstanding rate capacity and cycle life below − 40 °C. Comprehensive physical characterization techniques and theoretical simulations demonstrate that the solvation structure of the electrolyte defines the freezing point and electrochemical stability window, which is crucial for achieving fast charge carrier mobility and avoiding side effects. The pseudocapacitive hydrated tungsten oxide anodes and Prussian blue analogue cathodes with their open crystal structures achieve fast proton transport and storage, resulting in excellent electrochemical performance from − 60 to 25 °C (1000 cycles with no capacity fading at − 40 °C). Benefiting from the synergistic effect between the electrolyte and electrode materials, the fabricated proton pseudocapacitors exhibit remarkable low-temperature electrochemical performance. It achieves a maximum energy density of 39 Wh kg−1 and a broadened electrochemical window from 1.7 V at 25 °C to 2.3 V at − 60 °C. This work provides a comprehensive strategy to develop high-performance proton energy storage devices under ultralow-temperature conditions.

In Situ Growth of Amorphous MnO2 on Graphite Felt via Mild Etching Engineering as a Powerful Catalyst for Advanced Vanadium Redox Flow Batteries.

Owing to the advantages of low cost, high safety, and a desirable cycling lifetime, vanadium redox flow batteries (VRFBs) have attracted great attention in the large-scale energy storage field. However, graphite felts (GFs), widely used as electrode materials, usually possess an inferior catalytic activity for the redox reaction of vanadium ions, largely limiting the energy efficiency and rate performance of VRFBs. Here, an in situ growth of amorphous MnO2 on graphite felt (AMO@GF) was designed for application in VRFBs via mild and rapid etching engineering (5 min). After the etching process, the graphite felt fibers showed a porous and defective surface, contributing to abundant active sites toward the redox reaction. In addition, formed amorphous MnO2 can also serve as a powerful catalyst to facilitate the redox couples of VO2+/VO2+ based on density functional theoretical (DFT) calculations. As a result, the VRFB using AMO@GF displayed an elevated energy efficiency and superior stability after 2400 cycles at 200 mA cm-2, and the maximum current density can reach 300 mA cm-2. Such a high-efficiency and convenient design strategy for the electrode material will drive the further development and industrial application of VRFBs and other flow battery systems.

In-depth analysis of VARTM-based solid-state supercapacitors utilizing CNT-dispersed cobalt-bismuth-samarium ternary hydroxide on woven carbon fiber for enhanced energy storage

Multi-metal hydroxides possess unique physical and chemical properties, making them promising candidates for supercapacitor working electrodes. Enhancing their electrochemical performance can be achieved through a combination with carbon materials. In this study, we synthesized a composite material by hydrothermally dispersed 4, 6, and 10 wt% carbon nanotubes (CNT) into ternary cobalt-bismuth-samarium hydroxide (CoBiSm-TOH). These nanocomposites were employed as the material for the working electrode in a supercapacitor. The findings reveal that at 1.5 A/g, the specific capacitance of CNT3@CoBiSm-TOH, using a three-electrode system, was found to be 852.91 F/g, higher than that of CoBi-BOH, CoBiSm-TOH, CNT1@CoBiSm-TOH and CNT5@CoBiSm-TOH—measuring 699.69, 750.34, 789.54 and 817.79 F/g, respectively. Moreover, CNT3@CoBiSm-TOH electrodes exhibited a capacitance retention of around 88% over 10,000 cycles. To demonstrate practical applicability, CNT3@CoBiSm-TOH was grown on woven carbon fiber (WCF), and a solid-state supercapacitor device was developed using the VARTM (vacuum-assisted resin transfer molding). This device displayed a specific capacitance of 272.67 F/g at 2.25 A/g. Notably, it achieved a maximum energy density of 53.01 Wh/kg at a power density of 750 W/kg and sustained excellent cycle stability over 50,000 cycles, maintaining 70% of its initial capacitance. These results underscore the importance of interfacial nanoengineering and provide crucial insights for the development of future energy storage devices.

Fabrication of binary metal–organic frameworks of Ni–Mn@ZIFs(Cox·Zn1−xO) decorated on CF/CuO nanowire for high-performance electrochemical pseudocapacitors

Herein, metal–organic frameworks (MOFs) derived nanoflower-like based binary transition metal (Ni–Mn) are successfully fabricated by a simple synthesis method. The fabricated nanoflower-like structure displays a unique nanoflower-like architecture and internal porous channels constructed by MOF coated on CuO/CF/ZIFs (Cox·Zn1−xO) substrate, which is beneficial for the penetration of electrolyte and electron/ion transportation. The as-prepared CF/CuO/ZIFs (Cox·Zn1−xO)@BMOF(Ni–Mn) electrode materials present significant synergy among transition metal ions, contributing to enhanced electrochemical performances. The as-prepared CF/CuO/ZIFs (Cox·Zn1−xO)@BMOF(Ni–Mn) hybrid nanoflower-like display a high specific capacity of 1249.99 C g−1 at 1 A g−1 and the specific capacitance retention is about 91.74% after 5000 cycles. In addition, the as-assembled CF/CuO/ZIFs (Cox·Zn1−xO)@BMOF(Ni–Mn)//AC asymmetric supercapacitor (ASC) device exhibited a maximum energy density of 21.77 Wh·kg−1 at a power density of 799 W kg−1, and the capacity retention rate after 5000 charge and discharge cycles was 88.52%.

Improving Soft Subgrade Stability Using a Novel Sustainable Activated Binder Derived from By-Products

AbstractSoft soil concerns, due to high compressibility and low bearing capacity, prompted an investigation into stabilizing clay soil. Traditionally, binder including cement or lime has been used as stabilizers though a current requirement of alternatives is stem from environmental concerns. The study focused on the viability of using a novel binary activated blended binder composed of environmentally friendly materials, namely ground granulated blast furnace slag (GGBS) activated by cement kiln dust (CKD). The experimental work included investigating the impact of the developed binders on the Atterberg limits, standard Proctor compaction, California Bearing Ratio (CBR), unconfined compressive strength (UCS), and field-emission scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy. CBR tests were conducted after 7 days of curing or soaking, while UCS and SEM analyses were conducted after 7 and 28 days of curing. A fixed binder ratio of 9% was maintained, with GGBS blended at 25%, 50%, and 75% with CKD. For comparison, samples of untreated and treated soils with unary binders from GGBS and CKD were also prepared. Results indicated that activated binders notably decreased soil plasticity and maximum dry density, while elevating optimum moisture content, CBR, and UCS, especially in later stages of treated soil and unary GGBS binder. Unary CKD binder exhibited a similar trend to activated binders. The activating of 25% GGBS with 75% CKD provided the optimum binder which increased the mechanical strengths by about 6 times than untreated soil. SEM revealed substantial formations of C-S-H and C-A-H gel, along with ettringite, intensifying with time. This research provides viable outcomes for stabilizing clay soil using environmentally friendly binders, demonstrating significant improvements in soil properties, particularly when using the binary activated blended binder consisting of GGBS and CKD. Graphical Abstract

Exploring the post-harvest ‘window of vulnerability’ to landslides in New Zealand steepland plantation forests

Nature-based solutions (NbS) are actions to address societal problems. They are similar to soil and water bioengineering (SWB), where trees and forests are used to mitigate natural hazards. However, NbS can have unintended consequences.Forest-based NbS may involve the enhancement, rehabilitation or restoration of natural forests or planting of trees and forests to provide a range of services including the production of timber and wood. In New Zealand, planted steepland forests have been widely used as NbS for erosion control. While intact, these forests provide various beneficial ecosystem services. However, if these forests are harvested, there is a period of up to 6–‍8 years following clear-fell harvesting, known as the ‘window of vulnerability' (WoV) when the landscape is susceptible to rainfall-induced landslides. During this time, the combination of declining root strength and changes in soil hydrology can lead to shallow landslides, especially during heavy storms.This study focuses on three questions: determining whether there is a time within the WoV when susceptibility to rainfall-induced landslides, expressed as landslide density, reaches a maximum; are such landslides related to forestry infrastructure; and are those landslides connected to the stream network. We examined three areas in New Zealand (Tolaga Bay, Marlborough, and Tasman) where exceptional rain events triggered thousands of landslides on forest land harvested in the years immediately preceding those events. Using a range of high-resolution satellite imagery, we manually mapped rainfall-induced landslides and identified those due to the rain events.The maximum landslide number and density occurred on land harvested 1–4 years (and on average 2–3 years) before the event and varied slightly for each study area. Landslides also occurred in areas with trees up to harvest age of about 30 years and on areas with different vegetation covers, i.e., mature indigenous forests, pasture, scrub, etc. There were fewer landslides associated with forest infrastructure such as roads and landings than triggered on clearcut slopes. On average across the three study regions, about half the landslides were connected to streamlines, and so were able to deliver sediment and woody debris.Better information on susceptibility to rainfall-induced landslides following forest removal may help forest managers and regulators understand this hazard and what can (and cannot) be done to mitigate events which often result in ‘disastrous’ off-forest impacts as observed in New Zealand in recent years.

Laser-driven ion and electron acceleration from near-critical density gas targets: Towards high-repetition rate operation in the 1 PW, sub-100 fs laser interaction regime

Ion acceleration from gaseous targets driven by relativistic-intensity lasers was demonstrated as early as the late 1990s, yet most of the experiments conducted to date have involved picosecond-duration, Nd:glass lasers operating at low repetition rate. Here, we present measurements on the interaction of ultraintense (≈1020Wcm−2, 1 PW), ultrashort (≈70fs) Ti:Sa laser pulses with near-critical (≈1020cm−3) helium gas jets, a debris-free targetry with the potential for future compatibility with high (≈1 Hz) repetition rate operation. We provide evidence of α particles being forward accelerated up to ≈2.7−MeV energy with a total flux of ≈1011sr−1 as integrated over >0.1−MeV energies and detected within a 0.5−mrad solid angle. We also report on on-axis emission of relativistic electrons with an exponentially decaying spectrum characterized by a ≈10−MeV slope, i.e., five times larger than the standard ponderomotive scaling. The total charge of these electrons with energy above 2 MeV is estimated to be of ≈1nC, corresponding to ≈0.1% of the laser drive energy. In addition, we observe the formation of a plasma channel, extending longitudinally across the gas density maximum and expanding radially with time. These results are well captured by large-scale particle-in-cell simulations, which reveal that the detected fast ions most likely originate from reflection off the rapidly expanding channel walls. The latter process is predicted to yield ion energies in the MeV range, which compare well with the measurements. Finally, direct laser acceleration is shown to be the dominant mechanism behind the observed electron energization. Published by the American Physical Society 2024

Investigating the influence of oxygen-functionalized graphene nanosheets as an efficient multifunctional material for supercapacitor and electrocatalytic water splitting applications

Graphene oxide (GO) has received great research attention to develop its efficiency in electrochemical applications, particularly supercapacitor (SC) and water splitting systems. However, the presence of various oxygen moieties in GO drastically reduces the utilization of the material for commercial usages. In this work, we demonstrate the use of different sources to reduce graphene oxide (GO) nanosheets. The partially reduced GO not only improves the electronic conductivity but also boosts the interaction between the sp2- and sp3-hybridized carbon atoms. Benefiting from the partial reduction process, RGO is applied for the SC test in the three-electrode system and reveals a specific capacitance of 151.1 F g−1 at 1 A g−1 with a long cycle life. Furthermore, the asymmetric solid-state device can also be constructed from an M-GO cathode with an activated carbon anode, which displays a specific capacitance of 54.4 F g−1 at 1 A g−1, with a maximum energy density of 19.3 W h kg−1. Besides, the electrochemical water splitting performance of the partially reduced GO in KOH solution was also explored, confirming the effectiveness of the reduction process. This work highlights the successful preparation of RGO nanosheets, which may open a new route to constructing high-performance energy storage and conversion devices.

Sweet corn phytoglycogen dendrimers as a lyoprotectant for dry‐state protein storage

AbstractProtein biotherapeutics typically require expensive cold‐chain storage to maintain their fold and function. Packaging proteins in the dry state via lyophilization can reduce these cold‐chain requirements. However, formulating proteins for lyophilization often requires extensive optimization of excipients that both maintain the protein folded state during freezing and drying (i.e., “cryoprotection” and “lyoprotection”), and form a cake to carry the dehydrated protein. Here we show that sweet corn phytoglycogens, which are glucose dendrimers, can act as both a protein lyoprotectant and a cake‐forming agent. Phytoglycogen (PG) dendrimers from 16 different maize sources (PG1‐16) were extracted via ethanol precipitation. PG size was generally consistent at ~70–100 nm for all variants, whereas the colloidal stability in water, protein contaminant level, and maximum density of cytocompatibility varied for PG1‐16. 10 mg/mL PG1, 2, 9, 13, 15, and 16 maintained the activity of various proteins, including green fluorescent protein, lysozyme, β‐galactosidase, and horseradish peroxidase, over a broad range of concentrations, through multiple rounds of lyophilization. PG13 was identified as the lead excipient candidate as it demonstrated narrow dispersity, colloidal stability in phosphate‐buffered saline, low protein contaminants, and cytocompatibility up to 10 mg/mL in NIH3T3 cell cultures. All dry protein‐PG13 mixtures had a cake‐like appearance and all frozen protein‐PG13 mixtures had a Tg' of ~ −26°C. The lyoprotection and cake‐forming properties of PG13 were density‐dependent, requiring a minimum density of 5 mg/mL for maximum activity. Collectively these data establish PG dendrimers as a new class of excipient to formulate proteins in the dry state.

Microgravity analysis of periodic oscillations of heat and mass transfer of Darcy-Forchheimer nanofluid along radiating stretching surface with Joule heating effects

Reduced gravity impact on mixed convection flow plays a significant role for designing of electric-generating plants in space, unwanted effects of free convection, thermodynamic stability, space devices, surface tension and movement of nanoparticles. The novelty of present work is to find the impact of reduced gravity, Joule heating and thermal radiations on Darcy Forchheimer magnetized flow of nanofluid along the stretching porous sheet. The variable gravity is assumed as temperature dependent with maximum density and maximum density. The governing model is converted into convenient model to find physical thermo parameters. The primitive steady, real and imaginary equations are formed by using stokes and primitive transformations. To make programming algorithm in FORTRAN Lahey-90/95, the primitively terms are deduced in each equation. For tabular and numerical findings of steady velocity, temperature and concentration, the implicit form of finite difference approach is applied with Gaussian elimination method. The fluctuating skin friction, fluctuating heat transfer and fluctuating mass transfer are displayed by using steady outcomes in main formula. It is found that the magnitude of fluid velocity enhances as magnetic force, reduced gravity and Darcy Forchheimer parameter enhances. It is concluded that temperature distribution decreases as magnetic force enhances. It is noted that oscillating frequency in skin friction and heat transfer enhances as Schmidt number enhances. It is found that the maximum fluctuating layer in heat and mass transfer enhances as Prandtl number enhances.

Effect of trapezoidal plasma density region in bubble wakefield acceleration

In the process of bubble wakefield acceleration highly nonlinear region is developed inside plasma, which intuitively suggests that nonuniform plasma density having gradients may be more suited to achieve large nonlinearity in the system. Moreover, when an intense laser pulse propagates in a plasma, it is subjected to various instabilities and these instabilities can be controlled by plasma density profiles which effectively control the energy and flux of the accelerated particles. Considering all these points we investigate in the present work the scaling effect of up-ramp and down-ramp regions in plasma density profile on the bubble wakefield. These regions are separated by a plateau region (maximum density) enabling the density to have trapezoidal profile. With this density profile, the bubble wakefield acceleration is examined considering four different lengths of up-ramp and plateau regions keeping a constant down-ramp length. Increasing steepness of up-ramp length (larger density gradient), i.e., lowering the length of up-ramp and increasing the plateau length creates a bubble having higher wakefield strength, resulting into higher accumulation of plasma electrons at its tail and higher energy spectrum with higher kinetic energy gradient and Poynting flux of accelerated electrons.

A Novel Method for Full-Section Assessment of High-Speed Railway Subgrade Compaction Quality Based on ML-Interval Prediction Theory.

The high-speed railway subgrade compaction quality is controlled by the compaction degree (K), with the maximum dry density (ρdmax) serving as a crucial indicator for its calculation. The current mechanisms and methods for determining the ρdmax still suffer from uncertainties, inefficiencies, and lack of intelligence. These deficiencies can lead to insufficient assessments for the high-speed railway subgrade compaction quality, further impacting the operational safety of high-speed railways. In this paper, a novel method for full-section assessment of high-speed railway subgrade compaction quality based on ML-interval prediction theory is proposed. Firstly, based on indoor vibration compaction tests, a method for determining the ρdmax based on the dynamic stiffness Krb turning point is proposed. Secondly, the Pso-OptimalML-Adaboost (POA) model for predicting ρdmax is determined based on three typical machine learning (ML) algorithms, which are back propagation neural network (BPNN), support vector regression (SVR), and random forest (RF). Thirdly, the interval prediction theory is introduced to quantify the uncertainty in ρdmax prediction. Finally, based on the Bootstrap-POA-ANN interval prediction model and spatial interpolation algorithms, the interval distribution of ρdmax across the full-section can be determined, and a model for full-section assessment of compaction quality is developed based on the compaction standard (95%). Moreover, the proposed method is applied to determine the optimal compaction thicknesses (H0), within the station subgrade test section in the southwest region. The results indicate that: (1) The PSO-BPNN-AdaBoost model performs better in the accuracy and error metrics, which is selected as the POA model for predicting ρdmax. (2) The Bootstrap-POA-ANN interval prediction model for ρdmax can construct clear and reliable prediction intervals. (3) The model for full-section assessment of compaction quality can provide the full-section distribution interval for K. Comparing the H0 of 50~60 cm and 60~70 cm, the compaction quality is better with the H0 of 40~50 cm. The research findings can provide effective techniques for assessing the compaction quality of high-speed railway subgrades.

Assessment of biomass material as valuable electrode for high energy performance in microbial fuel cell with biodegradation of organic pollutant

Microbial fuel cells (MFC) have becomea more popular bio-electrochemical approach due to their environmental friendliness and sustainability. The anode is a vital component of the MFC, and its unstable material remains one of the primary causes of poor electron transportation throughout the reactor operations. This study seeks to improve MFC electron transport and naphthalene biodegradation by employing modified palm kernel shell (PKS)-based anode electrodes. These anode fabrications were successfully developed through the combination of PKS-based rGO hybridized into metal oxide modifiers (ZnO and TiO2). The anode electrodes were subsequently assigned PKS-rGO, PKS-rGO/TiO2, and PKS-rGO/ZnO. The power density displayed for PKS-rGO was 35.1 mW/m2, whereas the power density for the PKS-rGO/TiO2 composite anode was found to be 38.2 mW/m2. On the other hand, PKS-rGO/ZnO had a maximum power density of 45.4 mW/m2. The maximum current density (CD) in the anode PKS-rGO/ZnO was 114.0 mA/m2, indicating a comparable pattern of power output. Bacillus sp. and Niallia sp. were identified as exo-electrogens in the microbial study. In the MFC operation, the highest biodegradation efficiency was 85.50 % in the PKS-rGO settings, 92.80 % in PKS-rGO/TiO2, and94.30 % in PKS-rGO/ZnO. SEM and microbiological studies revealed that our anodes were highly biocompatible with microbes. Furthermore, this result proposes future research directions for the mortality ofanodic microbial communitiesin MFC.

Ultrastable Organic Anode Enabled by Electrochemically Active MXene Binder toward Advanced Potassium Ion Storage.

Conjugated carbonyl compounds are regarded as promising organic anode materials for potassium ion batteries (PIBs) due to their rich redox sites, excellent reversibility, and structural tunability, but their low electrical conductivity and severe solubility in organic electrolytes have substantially restricted their practical application. Herein, 2D MXene is utilized as an electrochemically active binder to fabricate perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) electrodes for high-performance PIBs. MXene, coupled with Super-P particles, served as a binder and conductive matrix to facilitate rapid ion and electron transport, restrain the solubility of PTCDA, promote potassium adsorption, and alleviate the volume expansion of PTCDA during potassiation. Consequently, the PTCDA electrode bonded by the MXene/Super-P system delivers excellent potassium storage performance in terms of a high capacity of 462 mAh g-1 at 50 mA g-1, superior rate capability of 116.3 mAh g-1 at 2000 mA g-1, and stable cycle performance over 3000 cycles with a low capacity decay rate of ∼0.0033% per cycle. When configured with the PTCDA@450 cathode, an all-PTCDA potassium ion full cell delivers a maximum energy density of 179.5 Wh kg-1, indicating the superiority of MXene as an electrochemically active binder to promote the practical application of organic anodes for PIBs.

Calcium Carbide and Wood Ash as Environmentally Friendly Soil Stabilisers for Enhanced Subgrade Performance

This study looks at the potential of waste calcium carbide (WCC) and wood ash (WA) as soil stabilisers to improve the engineering characteristics of subgrade soil. The investigation begins by characterising the properties of the untreated soil, indicating a liquid limit of 24.6%, linear shrinkage of 7.6%, and a non-plastic nature due to the lack of a plastic limit. In addition, the soil composition comprises a mere 2% of small particles measuring less than 63 µm, while a substantial 74% of the particles fall within the range of 63 µm to 2 mm. The particle density of untreated soil is found to be 2.86, beyond the typical soil limitations. Subsequently, an investigation was conducted to examine the impact of WCC and WA on Atterberg limits, compaction characteristics, and California Bearing Ratio (CBR) values. The findings indicate that the incorporation of WCC and WA leads to a reduction in the liquid limit by a maximum of 18.70% and linear shrinkage by a maximum of 55.26%. Compaction properties show an increase in optimal water content (OWC) and a minor decrease in maximum dry density (MDD). Importantly, CBR values significantly improved, with the soil treated with 6% WCC and WA demonstrating a CBR value of 26.9%, exceeding the subgrade acceptability requirement in road construction. This study highlights the potential of WCC and WA as cost-effective and sustainable soil stabilisers, particularly in areas where traditional stabilising materials are limited. More research into optimisation and long-term performance can help to realise the full potential of this novel method for soil stabilization.

Response surface optimization, kinetics, thermodynamics, and life cycle cost analysis of biodiesel production from Jatropha curcas oil using biomass-based functional activated carbon catalyst

A highly efficient activated porous catalyst, BPAC-500-S, derived from waste banana peels through a novel synthesis involving pyrolysis; and functionalization with 4-benzene diazonium sulphonate, has been developed. For comparison of catalytic activity, the material was also functionalized with sulphuric acid (BPAC-500-SX). The (BPAC-500-S) catalyst underwent impregnation and activation with ZnCl2, and its properties were extensively characterized using BET, SEM, XPS, XRD, FT-IR, and TGA techniques. Comparative analysis of catalysts obtained at different pyrolysis temperatures (400, 500, and 600 °C) revealed that BPAC-500-S pyrolyzed at 500 °C, exhibited maximum surface area (840.83 m2g-1) and sulphur density (4.7 %). Utilizing BPAC-500-S as a catalyst, an efficient process for biodiesel synthesis from Jatropha curcas oil (JCO) was developed, achieving a remarkable 98.91 % conversion, as confirmed by 1H NMR spectroscopy. Notably, life cycle cost analysis demonstrated a low biodiesel production cost of $ 0.70/L. The BPAC-500-S catalyst exhibited exceptional reusability maintaining more than 80 % biodiesel yield over seven reaction cycles. This study presents a sustainable and cost-effective approach to biodiesel production, emphasizing the potential of waste-derived catalysts in green and economically viable processes.

A biospecies-derived genomic DNA hybrid gel electrolyte for electrochemical energy storage.

Intrinsic impediments, namely weak mechanical strength, low ionic conductivity, low electrochemical performance, and stability have largely inhibited beyond practical applications of hydrogels in electronic devices and remains as a significant challenge in the scientific world. Here, we report a biospecies-derived genomic DNA hybrid gel electrolyte with many synergistic effects, including robust mechanical properties (mechanical strength and elongation of 6.98 MPa and 997.42%, respectively) and ion migration channels, which consequently demonstrated high ionic conductivity (73.27 mS/cm) and superior electrochemical stability (1.64 V). Notably, when applied to a supercapacitor the hybrid gel-based devices exhibit a specific capacitance of 425 F/g. Furthermore, it maintained rapid charging/discharging with a capacitance retention rate of 93.8% after ∼200,000 cycles while exhibiting a maximum energy density of 35.07 Wh/kg and a maximum power density of 193.9 kW/kg. This represents the best value among the current supercapacitors and can be immediately applied to minicars, solar cells, and LED lightning. The widespread use of DNA gel electrolytes will revolutionize human efforts to industrialize high-performance green energy.