Maximum Density Research Articles

Experimental studies on mechanical properties of metal fused filament fabricated SS316L

Fused filament fabrication is a simple and commercially popular additive manufacturing (AM) technique for developing high-accuracy polymer-based materials. In this experiment, a retrofit type of setup was developed to manufacture stainless steel 316L–based products. The current study focuses on the encapsulation of stainless steel with polylactic acid to prepare the filament for 3D printing. The effects of printing parameters such as layer thickness, infill density, and extruder temperature on responses like density, surface roughness, micro-hardness, and material/filament consumption have been studied. A Box–Behnken design approach was employed to systematically evaluate 15 specimens under varying conditions. The results revealed that a maximum relative density of 97% was achieved with a layer thickness of 0.2 mm, an extruder temperature of 215°C, and a 100% infill density. Additionally, the optimized infill density demonstrated a significant effect on both hardness and surface roughness, confirming the importance of precise control over processing conditions for improving the performance of the printed parts. The findings contribute to the advancement of metal-polymer composite filaments in additive manufacturing, highlighting their potential for producing complex, high-performance components.

Parametric Analysis of Indium Gallium Arsenide Wafer-based Thin Body (5 nm) Double-gate MOSFETs for Hybrid RF Applications.

The electrical behavior of a high-performance Indium Gallium Arsenide (In- GaAs) wafer-based n-type Double-Gate (DG) MOSFET with a gate length (LG1= LG2) of 2 nm was analyzed. The relationship of channel length, gate length, top and bottom gate oxide layer thickness, a gate oxide material, and the rectangular wafer with upgraded structural characteristics and the parameters, such as switch current ratio (ION/IOFF) and transconductance (Gm) was analyzed for hybrid RF applications. This work was carried out at 300 K utilizing a Non-Equilibrium Green Function (NEGF) mechanism for the proposed DG MOSFET architecture with La2O3 (EOT=1 nm) as gate dielectric oxide and source-drain device length (LSD) of 45 nm. It resulted in a maximum drain current (IDmax) of 4.52 mA, where the drain-source voltage (VDS) varied between 0 V and 0.5 V at the fixed gate to source voltage (VGS) = 0.5 V. The ON current(ION), leakage current (IOFF), and (ION/IOFF) switching current ratios of 1.56 mA, 8.49Í10-6 μA, and 18.3Í107 μA were obtained when the gate to source voltage (VGS) varied between 0 and 0.5 V at fixed drain-source voltage (VDS)=0.5V. The simulated result showed the values of maximum current density (Jmax), one and twodimensional electron density (N1D and N2D), electron mobility (μn), transconductance (Gm), and Subthreshold Slope (SS) are 52.4 μA/m2, 3.6Í107 cm-1, 11.36Í1012 cm-2, 1417 cm2V-1S-1, 3140 μS/μm, and 178 mV/dec, respectively. The Fermi-Dirac statistics were employed to limit the charge distribution of holes and electrons at a semiconductor-insulator interface. The flat-band voltage (VFB) of - 0.45 V for the fixed threshold voltage greatly impacted the breakdown voltage. The results were obtained by applying carriers to the channels with the (001) axis perpendicular to the gate oxide. The sub-band energy profile and electron density were well implemented and derived using the Non-Equilibrium Green's Function (NEGF) formalism. Further, a few advantages of the proposed heterostructure-based DG MOSFET structure over the other structures were observed. This proposed patent design, with a reduction in the leakage current characteristics, is mainly suitable for advanced Silicon-based solid-state CMOS devices, Microelectronics, Nanotechnologies, and future-generation device applications.

Development of machine learning-based standalone GUI application for predicting hydraulic conductivity and compaction parameters of lateritic soils

Hydraulic conductivity and compaction parameters are the key considerations in selecting lateritic soils for engineering construction. Nevertheless, the complexity and high cost of the required tests have driven many contractors and field engineers to skip them, resulting in a succession of engineering structure failures. To overcome this limitation, this study developed machine learning-based standalone GUI application to predict lateritic soils’ hydraulic conductivity (K), maximum dry density (MDD) and optimum moisture content (OMC) from indices including specific gravity, liquid limit, plasticity index, linear shrinkage and fine content. To achieve this goal, the geotechnical properties of three hundred samples, collected using grid sampling method from thirty different lateritic deposits in southwestern Nigeria, were evaluated through laboratory tests. The test results were used to train predictive models using artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS) and Gaussian process regression (GPR). The models’ performance was compared using coefficient of determination (R2), root mean squared error (RMSE), mean absolute percentage error (MAPE) and mean absolute error (MAE). Based on these performance metrics, ANN demonstrated the best performance (R2 = 0.9835, 0.9797, 0.9999; RMSE = 7.938, 0.252, 2.09E-08; MAPE = 0.288, 1.114, 1.587; MAE = 5.432, 0.169, 1.1E-08) for MDD, OMC and K, respectively, followed by GPR and then ANFIS. Thus, the ANN models were selected and embedded in a standalone GUI application to enhance easy and quick prediction of lateritic soils’ MDD, OMC and K. The validity of the ANN-based standalone GUI application was demonstrated by comparing it favorably to notable regression-based models in the literature.

Biohydrogen generation from distillery effluent using baffled up‐flow microbial electrolysis cell

AbstractMicrobial electrolysis cell (MEC) is gaining importance not only for effectively treating wastewater but also for producing hydrogen. The up‐flow microbial electrolysis cell (UPMEC) is an innovative approach to enhance the efficiency, and substrate degradation. In this study, a baffled UPMEC with an anode divided into three regions by inserting the baffle (sieve) plates at varying distances from the cathode was designed. The effect of process parameters, such as flow rate (10, 15, and 20 mL/min), electrode area (50, 100, and 150 cm2), and catholyte buffer concentration (50, 100, and 150 mM) were investigated using distillery wastewater as substrate. The experimental results showed a maximum of 0.6837 ± 0.02 mmol/L biohydrogen at 150 mM buffer, with 49 ± 1.0% COD reduction using an electrode of area 150 cm2. The maximum current density was 1335.94 mA/m2 for the flow rate of 15 mL/min and surface area of 150 cm2. The results showed that at optimized flow rate and buffer concentration, maximum hydrogen production and effective treatment of wastewater were achieved in the baffled UPMEC.Practitioner Points Biohydrogen production from distillery wastewater was investigated in a baffled UPMEC. Flowrate, concentration and electrode areas significantly influenced the hydrogen production. Maximum hydrogen (0.6837±0.02mmol/L.day) production and COD reduction (49±1.0%) was achieved at 15 mL/min. Highest CHR of 95.37±1.9 % and OHR of 4.6±0.09 % was observed at 150 mM buffer concentration.

Fabrication of stable slippery lubricant-infused porous surface on polymethyl methacrylate/thermoplastic polyurethane by supercritical CO2 foaming

The development of sustainable and efficient methods to prepare slippery lubricant-infused porous surface (SLIPS) is a profound work. In this study, using bilayer polymers restricting foaming mutually, bimodal cells were prepared through bilayer poly(methyl methacrylate) (PMMA). At the same time, uniform cells were prepared by bilayer PMMA /thermoplastic polyurethane (TPU). The prepared porous surfaces exhibited a high porosity (57% or more). TPU as dispersed phase increased the cell density of the PMMA/TPU surface with a maximum cell density of 5.5 × 107 cells/cm2 and an average cell size of 1.0 μm. SLIPS prepared on PMMA/TPU surface with high porosity and uniform microcellular had better stability, and the sliding angle (SA) remained less than 10° after centrifugal rotation at 8000r/min. Therefore, this work provides an approach to improve the surface cell density and produce SLIPS sustainably and efficiently.

Application of a microalga, Tetradesmus obliquus PF3, for NO and CO2 removal from actual flue gas via cultivating in wastewater.

Greenhouse gas (GHG) emissions, particularly anthropogenic emissions, are the primary drivers of climate change. The cultivation of microalgae represents a highly promising strategy for mitigating atmospheric GHG levels. The growth characteristics and GHG mitigation capabilities of Tetradesmus obliquus PF3 were investigated in domestic wastewater at a thermal power plant. The maximum cell density and productivity were 1.52 ± 0.01 g L-1 and 0.33 ± 0.01 g L-1 day-1, respectively. Utilizing a serial configuration of two reactors, the elimination efficiency of NO and CO2 attained values of 78 ± 4% and 14 ± 4%, respectively. NO concentration at the outlet was less than 24.6 ± 2.9 mg m-3, meeting the latest Chinese discharge limits. Besides, the recovery efficiency of NO and CO2 increased to 77 ± 8% and 2.24 ± 0.04%, respectively, compared to that of the single reactor (40 ± 3%, 0.9 ± 0.0%). A removal efficiency of over 90% was achieved for TN and TP in domestic wastewater. The concentrations of COD (76.5 mg L-1), NH4+-N (0.9 mg L-1), TN(6.31 mg L-1), and TP (0.35 mg L-1) in effluent were below the thresholds of 100 mg L-1, 25 mg L-1, none data, and 3 mg L-1, respectively, complying with the Chinese Discharge Standard (Class II criteria set forth) for Municipal Wastewater Treatment Plants Pollutants. The harvested biomass exhibited a high content of carbohydrates and proteins, making it a viable feedstock for biofuels and bio-fertilizers. Our results demonstrate that Tetradesmus obliquus PF3-based flue gas treatment technology can simultaneously realize GHG removal, wastewater bio-remediation, and biomass recovery.

DC and RF analysis of ScAlN/GaN/β-Ga2O3 and ScAlN/InGaN/GaN/β-Ga2O3 HEMTs on SiC substrate

Scandium aluminum nitride (ScxAl1-xN) is a promising material among group III nitrides, offering outstanding polarization properties resulting in very large carrier densities. We report the comparative analysis of Sc0.18Al0.72N/GaN/β-Ga2O3 and Sc0.18Al0.72N/InGaN/GaN/β-Ga2O3 HEMTs on Silicon carbide substrate. LG = 55 nm, Sc0.18Al0.72N/GaN/β-Ga2O3 HEMT demonstrated maximum current density (IDS) of 4.38 A/mm, very large carrier density (ns) of 2.34 × 1013 cm−2, large breakdown voltage (74 V) with low on-resistance (Ron ∼ 0.2 Ω mm), and cut-off frequency (fT)/maximum oscillation frequency (fmax) of 220/242 GHz. Introduction of a very thin 5 nm In0.1Ga0.9N layer in the channel, further improves the 2DEG (two-dimensional electron density), drain current, breakdown voltage. Furthermore, Sc0.18Al0.72N/InGaN/GaN/β-Ga2O3 heterostructure shows stable transconductance (gm) over wide gate bias. A gate voltage swing (GVS) of 7.72, IDS of 6.08 A/mm, and VBR of 105 V with Ron ∼ 0.138 recorded. These findings show the merits of scandium aluminium nitride barrier material, which enables the HEMTs for next generation radar and telecommunications.

Sulfur and nitrogen co-doped Ni/Co carbide 3D polyhedron nanoparticles with hollow core for hybrid supercapacitors

The methodologies for the synthesis of core-shell multilayered morphologies are being intensely explored. Following such scenarios, we report the fabrication of sulfur (S) and nitrogen (N) co-doped nickel/cobalt carbide (S,N@Ni/Co–C) hollow (carbon matrix) polyhedral nanoparticles (PNPs) by facile solvothermal and sulfurization process. The main objective of this research is to study the anomaly behind the structural deformation of the PNPs during the annealing and to propose a relevant method to preserve them by enhancing their abilities. Additionally, the electrochemical properties of the S, N@Ni/Co–C/nickel foam (NF) electrode are optimized and examined, exhibiting a high areal capacity of 563.3 μAh cm−2 and a notable cycling retention of 96 % at 7 mA cm−2 for 5000 cycles in a three-electrode system. Furthermore, the optimized electrode is employed as a positive electrode along with an activated carbon-coated NF as a negative electrode to fabricate a hybrid supercapacitor device which delivers a maximum energy density of 118.9 μAh cm−2 and a maximum power density of 7000 μA cm−2. Finally, it is used as a power source to drive a few real-time electronic devices, especially safety E-bands.

Electrodeposited Zn-Mn on three-dimensional electrodes as anodes in liquid and quasi-solid-state zinc-air batteries

Zinc-air batteries (ZABs) are eco-friendly and sustainable energy storage devices. There are different challenges to overcome in ZABs, where anodic issues such as shape changes, passivation, self-corrosion, and dendrite formation require urgent solutions. In this work, Zn and Zn-Mn alloys were electrodeposited on three-dimensional porous carbon electrodes varying the Mn composition (2, 20 and 40 g L−1) and studying its effect during the operation of a 6 M KOH liquid ZAB and a quasi-solid-state ZAB based on poly(vinyl alcohol)/poly(acrylic acid) PVA/PAA gel polymer electrolyte (GPE). Scanning electron microscopy (SEM) images indicated that Zn and Zn-Mn were deposited as platelet-like bi-dimensional structures. Additionally, the use of 20 and 40 g L−1 of the Mn precursor resulted in larger Zn deposition covering the 3D structure of the carbon paper. Elemental analysis indicated that the Mn content in Zn-Mn was 1.3, 2.4 and 6 %. In the aqueous ZAB, the Zn-Mn with 2.4 % Mn enabled to increase the maximum current density achieving the highest power density of 45 mW cm⁻2. In QSS-ZAB, Zn-Mn at 1.3 and 2.4. % Mn displayed higher stability to recovery after demanding different current densities, while the first anode displayed higher cyclability, presenting a similar round trip after 240 charge/discharge cycles This ZAB was maintained functional during 290 cycles vs. 120 cycles for Zn foil. The rechargeability was improved because of the decrease in Zn dendritic growth and passivation.

Modeling and spatialization of biomass and carbon stock using unmanned Aerial Vehicle Lidar (Lidar-UAV) metrics and forest inventory in cork oak forest of Maamora

Recently, the concerns about climate change have heightened the need for effective methods for estimating and mapping Biomass and Carbon stock at local, national, continental, and global scales. Reliable Biomass and Carbon stock quantification and spatialization is a challenge, especially in degraded Mediterranean Cork oak forest. To estimate and map Biomass (Btree−Total) and Carbon stock (Cst−total), we explored an improved approach using extracted metrics collected by Lidar-UAV (unmanned aerial vehicles Lidar), combined with forest inventory data. We approach three types of models for data analysis: Simple linear regression, multiple linear regressions, and stepwise multiple linear regression. The best Biomass and Carbon stock model fit is the Stepwise multiple linear regressions, involving the following metrics: maximum elevation, canopy cover and point cloud density and intensity. Our finding provides a quantification and spatialization Biomass and Carbon stock model based on Lidar-UAV metrics in Cork Oak Mediterranen forest and the results confirm the degraded state of Maamora Forest with a Biomass and Carbon stock relatively medium to low.

Information density threshold of urban road traffic signs based on visual comfort

The content and density of traffic signs directly affect the operation of urban road traffic and drivers. To overcome the limitations of quantitative research on the density threshold of traffic signs on urban roads, a real vehicle experiment was conducted to record the psychological characteristics of drivers. Four psychological parameters of drivers—pupil area, fixation intensity, heart rate change rate, and heart rate variability—were explored. Subsequently, principal component analysis was used to present a new index, S, divided into 5 grade scales, to represent the driving visual comfort level. The information entropy theory was applied to quantify the amount of information on road traffic signs that are included in driving tests, and a regression relationship between the traffic sign information and comfort index S was established. The visual psychological load thresholds for different comfort levels were −2.289≤S < −1.526 for very comfortable, 1.526≤S < −0.763 for relatively comfortable, −0.763≤S ≤ 0.763 for comfortable, 0.763<S ≤ 1.526 for uncomfortable, and 1.526<S ≤ 2.289 for very uncomfortable. To maintain the visual comfort of drivers, the information density of traffic signs should be less than 0.373 bits/m and the maximum information density of traffic signs should not exceed 0.507 bits/m. This conclusion provides a reference for the rational layout of traffic signs on urban roads.

Constructal design of cross‐flow heat exchanger with concave/convex fins

AbstractA contractual design of cross‐flow heat exchanger with concave/convex fins under fixed pressure drop is presented in this paper. An array of heated concave and convex fins are placed in a fixed area, and they are cooled by incoming cross flow, which is moving towards the fins due to constant pressure drop. The distances from fin to fin, the fin base, and the fin surface curvature (concave and convex) are free to morph and are constrained by the fin length and the height of cross flow. Bejan's number ranges from 105 to 107. The ratio of fin base‐to‐fin length is changed from 0.1 to 0.3. The dimensionless mass, momentum, and energy equations for two‐dimensional, steady, and incompressible flow are solved based on the finite volume numerical method. Also, the scale analysis method is used to compare heat transfer densities from concave and convex fins. The numerical results showed that the maximal convective heat transfer density for convex fins is higher than that of the concave fins for all Bejan numbers. The augmentations in the maximal heat transfer density are 2.1% at Be = 105, 4% at Be = 106, and 12.5% at Be = 107. Also, this is confirmed by the scale analysis method.

Treatments Technology and Mechanisms of East Asia Black Cotton Soil

The East Asia black cotton soil (BCS) cannot be used as embankment filling directly due to its high clay content, liquid limit, plasticity index, and low CBR strength (CBR &lt; 3%). This study evaluates the effects of treating East Asia BCS with lime, volcanic ash, or a combination of both on its engineering properties. Experiments were conducted to analyze the basic physical properties, swelling characteristics, and mechanical properties of the treated soil. Results indicate that lime addition significantly reduces the free swelling rate, improves limit moisture content, increases optimum moisture content, decreases maximum dry density, and enhances CBR value. Although volcanic ash also improves BCS performance, its effects are less pronounced than those of lime. The combined treatment with lime and volcanic ash exhibits superior performance, greatly reducing expansion potential and significantly increasing soil strength. Specifically, a mixture of 3% lime and 15% volcanic ash optimizes the liquid limit, plasticity index, and CBR value to 49.2%, 23.8, and 24.7%, respectively, meeting the JTG D30-2015 requirements and reducing construction costs. The treatment mechanisms involve hydration exothermic reactions, volcanic ash reactions, and semipermeable membrane effects, which collectively enhance the soil’s properties by producing dense, high-strength compounds.

Tailoring Polaron Dimensions in Lead-Tin Hybrid Perovskites.

Charge carriers in the soft and polar perovskite lattice form so-called polaron quasiparticles, charge carriers dressed with a lattice deformation. The spatial extent of a polaron is governed by the material's electron-phonon interaction strength, which determines charge carrier effective mass, mobility, and the so-called Mott polaron density, that is, the maximum stable density of charge carriers that a perovskite can support. Despite its significance, controlling polaron dimensions has been challenging. Here, experimental substantial tuning of polaron dimensions is reported by lattice engineering, through Pb/Sn substitution in CH3NH3SnxPb1-xI3. The polaron dimension is deduced from the Mott polaron density, which can be composition-tuned over an order of magnitude, while charge carrier mobility occurs through band transport, and remains substantial across all compositions, ranging from 10s to 100 scm2V s-1 at room temperature. The effective modulation of polaron size can be understood by considering the bond asymmetry after carrier injection as well as the random spatial distribution of Pb/Sn ions. This study underscores the potential for tailoring polaron dimensions, which is crucial for optimizing applications prioritizing either high charge carrier density or high mobility.

EXPERIMENTAL EVALUATION OF EXPANSIVE SOIL STABILIZED WITH WHEAT HUSK ASH AND SISAL FIBER

Everything starts with soil. Being a civil engineer, we are aware of how essential soil is to construction, as everything is dependent on it. Before building any kind of structure on top of soil, we examine the soil's characteristics and behavior to determine its strength and ability to support the weight of the structure to be built on top of it. In this study work, we used agricultural waste materials, such as wheat husk ash (WHA), as a stabilized material in soil at different percentages of 5%, 10%, and 15% to perform various tests on the soil to determine its qualities or strength. Sisal fibers are inexpensive, readily available locally, and environmentally benign, making them an excellent choice for enhancing soil properties. The stabilizing effect of sisal fiber on soil characteristics has been experimentally investigated in this work. In light of this, an experimental study is carried out using pricey, locally accessible soil that has been blended with various percentages of sisal fiber. In the CBR mold and UCS sampler, soil samples are prepared at their maximum dry density (MDD) matching to their optimum moisture content (OMC) both with and without Sisal Fiber and WHA. In the laboratory, CBR and UCS tests are carried out in accordance with the proportion of Sisal Fiber by dry weight of soil, which is determined to be 1%, 1.5%, or 2%. According to test results, the amount of sisal fiber in the soil increases with its saturated CBR and UCS value. When wheat husk ash and sisal fiber are added, the CBR of the mix increases and the pavement thickness decreases, resulting in lower construction costs and ultimately, more economical highway building. Key Words: Compaction test, CBR, UCS, WHA, Sisal Fiber

Nitrogen-doped vertical graphene for highly efficient hydrogen peroxide electrosynthesis in acidic environment

Electrochemical oxygen reduction (ORR) through a two-electron (2e−) pathway offers a green route for on-demand production of hydrogen peroxide (H2O2), which is an industrially valuable chemical as well as a renewable energy carrier. Metal-free carbon-based materials have been exploited as promising catalysts for H2O2 generation; however, they often exhibit poor performance with low productivity under acidic conditions. Herein, a nitrogen-doped vertical graphene catalyst is developed with a stable hydrophobic solid–liquid-gas three-phase interface (TPI) enabled by polydimethylsiloxane (PDMS) coating. The catalyst exhibits a high Faradaic efficiency (FE) of ∼ 80 % across a wide potential range from 0 to −0.6 V vs. reversible hydrogen electrode (RHE) at a maximum current density of 140 mA cm−2, resulting in a remarkably high H2O2 productivity of 21 mol gcatalyst−1h−1 in acid. Furthermore, a high concentration of H2O2 up to 10,500 ppm is obtained with the FE maintained at ∼ 75 %. Confocal laser scanning microscopy (CLSM) and fluorescence lifetime analysis reveal that the hydrophobic TPI increases gas diffusion and local pH value to enhance both activity and selectivity towards H2O2. This work provides valuable insights into the rational design of metal-free carbon-based catalysts for efficient H2O2 generation.

SPATIOTEMPORAL OF NITROGEN DIOXIDE (NO2) CONCENTRATION IN THE URBAN ENVIRONMENT OF KLANG VALLEY, MALAYSIA

The high concentration of nitrogen dioxide (NO2) directly results in Klang Valley’s air quality deterioration, causing a public health risk. This study was conducted to analyse the daily-averaged and annual concentration of nitrogen dioxide (NO2) on a spatial-temporal scale at five continuous monitoring stations under the Department of Environment (DOE) in Klang Valley, namely, Klang, Shah Alam, Petaling Jaya, Kajang, and Cheras from 2000 to 2009 using Man-Kendall statistical analysis and interpolation technique in Geographic Information System (GIS). The result clearly showed that the Petaling Jaya station was identified as the most polluted compared to other stations, with an average concentration of more than 0.050 ppm every year and reaching the maximum concentration of 0.069 ppm where the mean was 0.030 in 2001. Based on the p-value derived from the Mann-Kendall statistical analysis, the Klang, Petaling Jaya, Shah Alam, and Cheras stations recorded a significant trend with p-values &lt; 0.05 at 0.0001 and 0.020, respectively. The annual concentration of NO2 in all the stations was in the range of 0.015 to 0.04 ppm from 2004 to 2009, compared to 0.005 to 0.01 ppm from 2000 to 2003. The highest annual-averaged NO2 concentration was reported at the Petaling Jaya station between 0.035 and 0.004 ppm for all years except 2007 and 2009 when concentrations were in the 0.03 to 0.035 ppm. Notably, the Petaling Jaya station had the highest annual NO2 concentration, which ranged from 0.025 to 0.04 ppm due to emissions from motor vehicles. The major pressure on road infrastructure was recognised, mainly a lack of space to accommodate the effect of the maximum density of motor vehicles and traffic, resulting in traffic congestion in the city centre.

Understanding effects of observing affordance-driven action during motor imagery through EEG analysis.

The aim of this paper is to investigate the impact of observing affordance-driven action during motor imagery. Affordance-driven action refers to actions that are initiated based on the properties of objects and the possibilities they offer for interaction. Action observation (AO) and motor imagery (MI) are two forms of motor simulation that can influence motor responses. We examined combined AO+MI, where participants simultaneously engaged in AO and MI. Two different kinds of combined AO+MI were employed. Participants imagined and observed the same affordance-driven action during congruent AO+MI, whereas in incongruent AO+MI, participants imagined the actual affordance-driven action while observing a distracting affordance involving the same object. EEG data were analyzed for the N2 component of event-related potential (ERP). Our study found that the N2 ERP became more negative during congruent AO+MI, indicating strong affordance-related activity. The maximum source current density (0.00611 A/mm ) using Low-Resolution Electromagnetic Tomography (LORETA) was observed during congruent AO+MI in brain areas responsible for planning motoric actions. This is consistent with prefrontal cortex and premotor cortex activity for AO+MI reported in the literature. The stronger neural activity observed during congruent AO+MI suggests that affordance-driven actions hold promise for neurorehabilitation.

Architecting hydrogen-bonded and π–π conjugated MOF@NiPc networks towards enhanced energy storage

High-capacity metal–organic framework materials is constrained by their poor electron transport and unstable in aqueous. Herein, a spherical cobalt–nickel-based metal–organic framework (CoNi-MOF) micro-architecture with 18-π aromatic electron system of nickel phthalocyanine (NiPc) nanorods has been designed. In this system, intermolecular hydrogen (H) bonds between O in CoNi-MOF and H in nickel phthalocyanine (NiPc), along with longitudinal π-π stacking structure, could improve electron transport and structuralstability of MOFs. Benefiting from the 3D electron transport highways and “locking” effect of H bonds along with longitudinal π-π stacking structure, the optimized CoNi-MOF@NiPc electrode exhibits remarkable specific capacity of 807.365C g−1 at current density of 1 A/g, along with great cycling stability with 96.19 % capacity retention after 5000 cycles at 5 A/g, which is superior to the individual components. Besides, CoNi-MOF@NiPc//AC hybrid supercapacitor has been fabricated, which displays a maximum energy density of 130.68 Wh kg−1 at 962.09 W kg−1 and excellent cyclability (93.58 % capacity retention after 10,000 cycles). This study opens a new avenue for the design of organic electrodes and provides a new insight into H bond and π-π stacking structure effect toward advanced energy storage materials.

Coal-based graphitized activated carbon for solar energy powered supercapacitor IoT applications

Solar cells show promise as energy conversion gadgets, but their extended use is limited by intermittent sunlight. Self-powered solar cell integration with an electrical energy storage system could be one solution to this problem. Therefore, we have developed a coin cell supercapacitor (SC) device based on coal-based graphitized carbon materials and integrated with solar cells to assess its efficiency for energy transformation and storage for practical validity. Supercapacitor carbon electrode was developed from a naturally abundant carbon precursor i.e. low-grade coal using molasses as binder, for the fabrication of high-quality SC devices. The fabricated supercapacitor exhibits a notable 127 F g−1 specific capacitance, maintaining 92 % of its initial value for up to 10,000 charge/discharge cycles at 5 A g−1, and a maximum energy density of 70.57 Wh kg−1 and power density of 2000.17 W kg−1. In order to create a self-sustaining power pack, the SCs (4 V) are integrated with a commercial solar cell (6 V, 750 mAh). Importantly, in the presenceof natural sunlight, the solar-powered as-fabricated supercapacitor bankcan significantly power a commercial IoT module (4–6 V, 600 mAh) demonstrating its potential for successful solar-to-electric energy transformation and storage. The findings demonstrate that solar-powered coal-based SC can be explored as an incredibly rapid future-proof energy storage technology that can help reduce energy demand in the foreseeable future.