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Abstract This study presents a novel approach to fabricating interdigitated capacitive (IDC) touch sensors using graphite-based pencils on a wood substrate. The sensors were designed to detect touches and pressure variations, offering a cost-effective and environmentally friendly solution for sensor fabrication. The fabrication process involved abrasion of graphite pencils on a wooden substrate to create conductive traces, followed by the integration of interdigitated electrode structures. Capacitance variations resulting from touch interactions were investigated to calibrate sensor responses for tailored tasks. The sensitivity of the sensor was found to be 1.2 pF/kPa, highlighting its responsiveness to pressure variations. Additionally, the sensors were interfaced with an Arduino Uno microcontroller board to demonstrate practical applications, such as replicating arrow key functionality. Additionally, the sensors exhibit sensitivity to environmental factors, with the relative change in capacitance increasing from 0.1 to 0.65 as relative humidity ranges from 30 to 90%. Furthermore, variations in temperature from 30 to 60ºC result in a relative change in capacitance increasing to approximately 0.5. The results indicate the feasibility and versatility of using wood-based substrates and graphite-based pencils for fabricating IDC touch sensors, offering promising prospects for sustainable and accessible sensor technology.

Abstract In real-life situations, we have to analyze the data that contains the atypical observations, and the presence of outliers has adverse effects on the performance of ordinary least square estimates. In this situation, redescedning M-estimators, proposed by Huber (1964), are used to tackle the effects of outliers to increase the efficiency of least square estimates. In this study, we introduce a redescending M-estimator designed to generate robust estimates by mitigating the influence of outlier observations, even when the tuning constant is set to low values. This innovative estimator exhibits enhanced linearity at its core and maintains continuity throughout its range. Our proposed estimator stands out for its novelty, simplicity, differentiability, and practical applicability across real-world scenarios. The results of the proposed redescedning M-estimators are compared with existing robust estimators using an extensive simulation study. Two examples based on real-life data are also added to validate the performance of the suggested function. The formulated redescedning M-estimator produced efficient results as compared to all the considered redescedning M-estimators.

Abstract Textile industry dye effluent contains a mixture of different kinds of dyes. Many times, photocatalysis is targeted as a solution for the treatment of dye effluent from the textile industry. Many researches have been published related to the photocatalysis of single textile dyes but in the real-world scenario, effluent is a mixture of dyes. Magnesium oxide (MgO) is used as a photocatalyst to treat a mixture (binary solution) of Methylene blue (MB) and Methylene violet (MV) along with individual MB and MV dyes in this article. MgO shows remarkable photocatalytic activity at about 93 and 88% for MB and MV dye in binary solution within 135 min. Furthermore, to study the influence of process parameters, experiments are designed with the help of the central composite design (CCD), and Response surface methodology (RSM) is used to study the interactions between parameters. For this study, five parameters are selected i.e., Photocatalyst dosage, initial concentration of both dyes, time of exposure to the light source, and pH of the binary solution. The photocatalytic process is also optimized and finally optimization of process parameters is validated with an experiment. The result of the validation experiment is very close to the predicted photocatalytic activity.

Abstract Electrowetting behaviour for carbon nanotubes (CNT) grown on stainless steel mesh was investigated. The effect of temperature, time, and applied bias voltage on the contact angle of water droplets was studied. The impact of temperature variation on contact angle was also performed for the temperature ranging from 25 to 70 °C. A decrement of contact angle by 68% was observed for the mentioned range indicating a transition from a hydrophobic to hydrophilic nature. A similar trend was observed on the application of electric potential to the CNT-modified stainless-steel mesh ranging from 0 to 8 V with a transition of contact angle from 146 to 30 deg respectively. A comparative analysis for the contact angle variation with time for CNT-coated mesh and uncoated mesh was performed for 180 min. It is observed that uncoated mesh shows a reduction in contact angle to 0 deg with time while the CNT coated mesh shows surplus hydrophobicity with a 2 deg decrement in the extent of time. CNT-modified mesh successfully absorbs 95% of rhodamine B (RB) dye and detergent from water in 10 cycles.

Sol–gel method was used to prepare Sr1-xCdxZn2Fe4O11 (x = 0.00, 0.02, 0.06, 0.1) R-type hexaferrite. The synthesized materials were sintered at 850oC and desired phase was obtained. X-ray diffraction analysis confirms that R-type hexaferrite exists only as a single phase. Using the Scherer formula, crystallite size for all of the prepared samples was found to be in the range of 10.39–12.62 nm. Crystallite size (D), the lattice parameters (a, c), and the cell volume (Vcell), d-spacing, bulk density, X-ray density, porosity, dislocation density and micro strain were determined in structural analysis. Fourier transform infrared spectroscopy method was used to identify the metal-oxygen vibrations at different locations. FT-IR verifies the presence of the Fe–O stretching vibration band at 743 and 867 cm−1. The typical grain size in surface morphology investigation ranges from 0.56 to 0.82 μm. Dielectric response of ferrite ceramic samples replaced with Cd2+ was investigated in the frequency range of 1 MHz–3 GHz. The AC conductivity rises with an increase in frequency because they are proportional to one another. This increasing tendency is effectively described by the theory of Maxwell-Wagner and Koop. Q-values remain constant as frequency rises and behaves independently of frequency as long as frequency reaches 1.7 GHz. These types of materials are utilized in high-frequency applications including frequency filters and resonant circuits. All of the magnetic properties determined by analyzing the M − H loops, including saturation magnetization (Ms), retentivity (Mr), and coercivity (Hc), exhibit an increasing trend as the substitution of Cd2+ rises. Ms (49.76–56.38 emu/g), Mr (15.82–18.30 emu/g) and Hc range from 203.20 Oe to 215.80 Oe. Grain size decreases cause arise in coercivity, which is caused by an enhancement in magneto-crystalline anisotropy. Overall results suggest that Cd2+ replaced R-type hexagonal ferrites are a great resource for longitudinal recording media; they have the potential to be used in a wide variety of electronic applications, including resonant circuits and high-frequency filters, security, detecting and switching.

The present study analyzes on the reviews carried out by the previous researchers on the entropy generation caused by the flow and heat transfer of several composite nanofluids subject to varieties of geometries under the influence of several constraints of motions. The composite nanofluids include binary hybrid nanofluids and ternary hybrid nanofluids involving disparate base fluids with different suitable nanoparticles. The geometries considered are deformed surfaces (stretched/shrunk sheets, cylinders, and disks), channels and cavities. Several numerical techniques such as Runge-Kutta method and finite element/difference/volume methods are implemented in the investigations. The major and significant outcome of the review analysis is the entropy comparison for different types of nanofluids. Growth of the volume percentage of nanoparticles at a fixed mass flow rate enhances entropy formation. When porosity strength increases, the irreversible entropy production caused by fluid friction results in increased thermal efficiency of certain systems than magnetic entropies. Compared to single nanofluids, hybrid nanofluids display the maximum entropy. With increasing Rayleigh numbers, the frictional and magnetic entropies in composite nanofluids ameliorate significantly than thermal entropy.

Abstract The fabrication of a Poly (vinylidene fluoride) membrane (PVDF) and ceramic-assisted bismuth vanadate-polyvinylidene fluoride (BiVO4-PVDF) composite membrane was achieved through the utilization of the electrospinning technique. The composition and structure of the fabricated membranes were characterized by X-ray powder diffraction, Raman analysis, scanning electron microscopy, Thermo gravimetric analyzer, Fourier transform infrared spectroscopy, and UV–Vis spectroscopy techniques. The prepared polymeric membranes were then utilized for catalytic investigation and to explore, how structure affects catalytic activity using 5 mg/L, 10 mL methylene blue (MB) dye solution. Ultrasonication, visible light irradiation, and the combination were used to study piezocatalysis, photocatalysis, and piezo-photocatalysis, moreover, degradation intermediates were also explored using scavengers. Electrospun BiVO4-PVDF (BV-PVDF) composite has been found to have better piezocatalytic and photocatalytic properties than PVDF. The experimental findings reveal that the composite of BiVO4-PVDF demonstrates the highest efficiency in dye degradation, achieving a maximum degradation rate of 61% within a processing time of 180 min. The rate of degradation was calculated to be 0.0047 min−1, indicating a promising potential for the composite in the field of dye degradation.

Abstract The mechanochemical ball milling followed by heating at 650 °C for 5 h successfully produced the single-phase Bi2VO5.5 powder. Catalytic activity for methylene blue dye degradation was investigated. Raman spectroscopy and X-ray diffraction were used to confirm the phase formation. The sample’s charge carrier transportation behavior was ascertained using time-dependent photocurrent analysis. The piezo-photocatalysis experiment yielded a 63% degradation efficiency for the ball-milled Bi2VO5.5 sample. The pseudo-first-order kinetics of the piezo-photocatalytic dye degradation are discerned, and the significant k value of 0.00529 min−1 is achieved. The scavenger test declares the h+ radical is the predominant active species during the piezo-photocatalysis experiment. Vigna radiata seeds were used in a phytotoxicity test to evaluate the germination index. The mechanochemical activation method facilitates reactions by lowering reaction temperature and time. The effect of improved piezo-photocatalytic efficiency on the ball-milled Bi2VO5.5 powder is an unexplored area, and we have attempted to investigate it. Here, ball-milled Bi2VO5.5 powder achieved improved dye degradation performance.

Tungsten oxide (WO3), Iron and vanadium co-doped tungsten oxide (FeVWO3), and the composite of iron and vanadium co-doped tungsten oxide with graphitic carbon nitride (FeVWO3@g-C3N4) were prepared for the photocatalytic study. WO3 and FeVWO3 were synthesized by co-precipitation, and the composite FeVWO3@g-C3N4 was synthesized by an ultra-sonication approach. All the prepared materials were analyzed by different techniques. Structural study was done by XRD, functional group analysis by FTIR, and SEM was used for the morphological study of the nanoparticles. EIS measurements were done to investigate the electrical properties of fabricated materials. Photocatalysis was performed for the band gap analysis. Pendimethalin (PM) a herbicide and aspirin (pharmaceutical product) were used in photocatalysis and degraded by the prepared photocatalysts (WO3, FeVWO3, and FeVWO3@g-C3N4). WO3 and FeVWO3 have 2.62 eV and 2.34 eV Eg values of band gap, respectively. FeVWO3 has a lower Eg value than WO3. The decrease is due to the doping, and generation of further energy levels in the band gap of the pure sample, and these energy levels cause changes in the electronic structure of the sample. The composite shows a high degradation efficiency. The percentage degradation of pendimethalin and aspirin by FeVWO3@g-C3N4 was 82.26 % and 92.84 %. It is because of the presence of g-C3N4 which provides greater surface area for better degradation efficiency.

Abstract A thermoregulating smart textile based on phase change material (PCM) polyethylene glycol (PEG) was prepared by chemically grafting carboxyl-terminated PEG onto cotton. Further deposits of graphene oxide (GO) nanosheets were made on the PEG grafted cotton (PEG-g-Cotton) to improve the thermal conductivity of the fabric and to block harmful UV radiation. The GO-PEG-g-Cotton was characterized by Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and field emission-scanning electron microscopy (FE-SEM). With an enthalpy of 37 and 36 J/g, respectively, the DSC data revealed that the functionalized cotton's melting and crystallization maxima occurred at 58 °C and 40 °C, respectively. The thermogravimetric analysis (TGA) presented that GO-PEG-g-Cotton was thermally more stable in comparison to pure cotton. The thermal conductivity of PEG-g-Cotton increased to 0.52 W/m K after GO deposition, while pure cotton conductivity was measured as 0.045 W/m K. The improvement in the UV protection factor (UPF) of GO-PEG-g-Cotton was observed indicating excellent UV blocking. This temperature-regulating smart cotton offers a high thermal energy storage capability, better thermal conductivity, thermal stability, and excellent UV protection.

This study aims to investigate the utility of using 15PbF2–(60x)TeO2–25WO3–xNd2O3 (0.1 ≥ x ≥ 1.5) glasses in the nuclear shielding applications for mixed radiation fields at energies ranging from 15 keV to 15 MeV. The effect of Nd3+ ions on gamma attenuation properties of the present glass system was discussed in detail. The radiation attenuation features were investigated for the present glass system by using Monte Carlo radiation transport simulation via Geant4 toolkit. The simulation results were theoretically approved by using Phy-X approach over the entire considered energy range. The obtained results indicate that the values of Zeff and Neff were both highest in the in the τ/ρ dominated energies due to the atomic number dependence of the cross sections of the τ/ρ absorption processes. Moreover, FNRCS values were 0.1152, 0.1152, 0.1153, and 0.1153 cm−1 for PWTN1, PWTN2, PWTN3, and PWTN4 respectively. Finally, an extensive comparative study is also presented between the studied glass system and standard traditional shielding materials. The study suggests PWTN4 is the best photon shield amongst the studied PWTN-glasses. Resumen: Este estudio tiene como objetivo investigar la utilidad del uso de vidrios 15PbF2–(60x)TeO2–25WO3–xNd2O3 (0,1 ≥ x ≥ 1,5) en las aplicaciones de blindaje nuclear para campos de radiación mixtos a energías que van desde 15 keV hasta 15 MeV. Se discute en detalle el efecto de los iones Nd3+ sobre las propiedades de atenuación gamma de este sistema de vidrio. Se investigan las características de atenuación de radiación para este sistema de vidrio utilizando la simulación de transporte de radiación de Monte Carlo con el conjunto de herramientas Geant4. Los resultados de la simulación se han corroborado teóricamente utilizando la aproximación Phy-X en todo el rango de energías considerado. Los resultados obtenidos indican que los valores de Zeff y Neff fueron los más altos en las energías dominantes en τ/ρ debido a la dependencia con el número atómico de las secciones transversales de los procesos de absorción τ/ρ. Además, los valores de FNRCS fueron 0,1152; 0,1152; 0,1153 y 0,1153 cm−1 para PWTN1, PWTN2, PWTN3 y PWTN4, respectivamente. Por último, también se presenta un extenso estudio comparativo entre el sistema de vidrio analizado y los materiales de blindaje estándar y tradicionales. El estudio muestra que PWTN4 es el mejor escudo de fotones de entre los vidrios PWTN estudiados.

Optoelectronic devices designed with double perovskites are potentially emerging nowadays because of their interesting properties, such as simple and stable crystal structure. Our study theoretically explored the optoelectronic, mechanical, and thermoelectric characteristics of Rb2ScTlX6 (X = Cl, Br, I) based on the density functional theory of the Wein2k code. The thermodynamic and structural stability is determined based on the enthalpy of formation and tolerance factor. The character of the compositions has been checked that either they are ductile or brittle by the elastic constants which are used to measure Passion and Pugh's ratio. For the elaboration of band gaps, Tran-Blaha mBJ potential is used, and the measured values of energy bandgaps are 3.5, 3.0, and 2.4 eV for Rb2ScTlCl6, Rb2ScTlBr6, and Rb2ScTlI6, respectively, using TB-mBJ plus spin-orbital coupling (SOC). These compositions are potentially used in solar cell devices like heterojunction solar cells because their electronic characteristics are controllable. In the energy range 0–12 eV, the compositions under consideration exhibit a single-peaked response, while the replacement of anions from Cl to I caused a shift in optical structures towards lower energies. The significant value of the figure of merits 0.77–0.95 makes them suitable for thermoelectric device applications.

Abstract This study focuses on analyzing the poling effect of BaBi4Ti4O15 (BBT) on the basis of photo and piezo‐catalysis performance. BBT powder is prepared via a solid state reaction followed by calcination at 950 °C for 4 h. BBT is characterized by an X‐ray diffractometer, scanning electron microscopy, Raman spectroscopy, and X‐ray photoelectron spectroscopy. The optical bandgap of BBT is evaluated with the help of Tauc's plot and found to be 3.29 eV, which comes in the photon energy range of ultra‐violet radiation. BBT powder is poled by using Corona poling in the presence of 2 kV mm−1 of electric field. An aqueous solution of methyl blue (MB) dye in the presence of UV radiation is used to evaluate the photo/piezocatalysis performance. Photocatalysis, piezocatalysis, and photo–piezo catalysis degradation efficiencies of poled and unpoled BBT powder are tested for 120 min of UV light irradiation. Photo–piezocatalysis shows degradation efficiencies of 62% and 40% for poled and unpoled BBT powder, respectively. Poling of BBT powder shows significant enhancement in degradation performance of MB dye in aqueous solution. Scavenger tests are also performed to identify reactive species.

Abstract In the present numerical simulation work, effective elastic and piezoelectric properties are calculated and a comparative study is conducted on a cement matrix‐based piezocomposite with 0–3 and gyroid triply periodic minimal surface (TPMS) inclusions. The present study compares the effective properties of different piezoelectric materials having two different types of connectivity of the inclusions namely, 0–3 inclusions where the inclusions are physically separated from each other and are embedded within the matrix and the second one is TPMS inclusions having interpenetrating phase type connectivity. Effective properties are calculated for four different materials at five different volume fractions namely, 10%, 15%, 20%, 25%, and 30% volume fractions of inclusion by volume. In terms of effective properties and direct piezoelectric effect, TPMS piezocomposite is found to perform better compared to 0–3 piezocomposite. Lead‐free piezoelectric material 0.5Ba(Ca0.8Zr0.2)O3 − 0.5(Ba0.7Ca0.3)TiO3 demonstrates better performance compared to all other material inclusions studied. The present study attempts to highlight improved piezoelectric effective properties of lead‐free material‐based piezocomposites with TPMS inclusions.

Ferroelectric materials are known to possess multicatalytic abilities that are nowadays utilized for removing organic pollutants from water via piezocatalysis, photocatalysis, piezo-photocatalysis, and pyrocatalysis processes. The Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZTO) ceramic is one such ferroelectric composition that has been extensively studied for electrical and electronic applications. Furthermore, the BCZTO ceramic has also shown remarkable multicatalytic performance in water-cleaning applications. The present review explores the potentiality of BCZTO for water-cleaning and bacterial-killing applications. It also highlights the fundamentals of ferroelectric ceramics, the importance of electric poling, and the principles underlying piezocatalysis, photocatalysis, and pyrocatalysis processes in addition to the multicatalytic capability of ferroelectric BCZTO ceramic.

A basic urea technique was successfully used to synthesize Mg/Al-Layered double hydroxides (Mg/Al LDHs), which were then calcined at 400 °C to form Mg/Al-Layered double oxides (Mg/Al LDOs). To reconstruct LDHs, Mg/Al LDOs were fabricated with different feeding ratios of Ni by the co-precipitation method. After synthesis, the Ni/Mg/Al-layered double hydroxides (NMA-LDHs) with 20% and 30% Ni (S1 and S2) were roasted at 400 °C and transformed into corresponding Ni/Mg/Al-layered double oxides (NMA-LDOs) (S1a and S2b, respectively). The physiochemical properties of synthesized samples were also evaluated by various characterization techniques, such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR), and Brunauer, Emmett, and Teller (BET). The adsorption behavior of methyl orange (MO) onto the synthesized samples was evaluated in batch adsorption mode under varying conditions of contact time, adsorbent quantity, and solution pH. As the dosage amount increased from 0.01–0.04 g, the removal percentage of MO dye also increased from 83% to 90% for S1, 84% to 92% for S1a, 77% to 87% for S2, and 93% to 98% for S2b, respectively. For all of the samples, the adsorption kinetics were well described by the pseudo-second-order kinetic model. The equilibrium adsorption data were well fitted to both Langmuir and Freundlich models for methyl orange (MO). Finally, three adsorption-desorption cycles show that NMA-LDHs and NMA-LDOs have greater adsorption and reusability performance for MO dye, signifying that the design and fabrication strategy can facilitate the application of the natural hydrotalcite material in water remediation.

Abstract Reduced graphene oxide (rGO)/bismuth vanadate BiVO4 composites are fabricated with varied rGO amounts (0, 1, 2, and 3 wt%) through the synergetic effects of ultrasonication, photoinduced reduction, and hydrothermal methods, and the materials are tested as tools for sonophotocatalytic methylene blue (MB) dye degradation. The effect of rGO content on the sonophotocatalytic dye degradation capabilities of the composites are explored. Characterization of the proposed materials is done through transmission electron microscopy (TEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), Fourier transformation infrared spectroscopy as well as scanning electron microscopy. The coexistence of BiVO4 and rGO is confirmed using Raman spectroscopy and XRD. TEM confirms the existence of interfaces between rGO and BiVO4 and XPS affirms the existence of varied elemental oxidation states. In order to investigate the charge carriers transportation, time‐dependent photocurrent responses of BiVO4 and 2 wt%‐ rGO/BiVO4 are done under visible light irradiation. The sonophotocatalytic MB dye degradation in an aqueous medium displays promising enhancement with rGO doping in rGO/BiVO4 composite. The 2 wt%‐ rGO/BiVO4 sample exhibits ≈52% MB dye degradation efficiency as compared to pure BiVO4 (≈25%) in 180 min of the sonophotocatalysis experiment. Phytotoxicity analysis through germination index is done using vigna radiata seeds.

This study aimed to investigate the compact 1-bit coding metamaterial design with various conventional and cuboid shapes by analysing the bistatic scattering patterns as well as the monostatic radar cross-section for microwave applications. The construction of this metamaterial design depends on binary elements. For example, 1-bit coding metamaterial comprises two kinds of unit cell to mimic both coding particles such as ‘0’ and ‘1’ with 0° and 180° phase responses. This study adopted a 1 mm × 1 mm of epoxy resin fibre (FR-4) substrate material, which possesses a dielectric constant of 4.3 and tangent loss of 0.025, to construct both elements for the 1-bit coding metamaterial. All simulations were performed using the well-known Computer Simulation Technology (CST) software. The elements were selected via a trial-and-error method based on the phase response properties of the designs. On the other hand, the phase response properties from CST software were validated through the comparison of the phase response properties of both elements with the analytical data from HFSS software. Clear closure was obtained from these findings, and it was concluded that the proposed conventional coding metamaterial manifested the lowest RCS values with an increasing number of lattices. However, the cuboid-shaped design with 20 lattices demonstrated an optimised bistatic scattering pattern of −8.49 dBm2. Additionally, the monostatic RCS values were successfully reduced within the 12 to 18 GHz frequency range with −30 to −10 dBm2 values. In short, the introduced designs were suitable for the proposed application field, and this unique phenomenon is described as the novelty of this study.

BaTiO3-polymer paint composites were fabricated to examine piezocatalysis activities. Dye degradation and antibacterial activities were recorded under ultrasonication. The effect of polarization was also examined for the catalysis process. There were significant enhancements in catalysis performance in the poled sample; 80–90% dye degradation was recorded (240 min) in poled samples of BaTiO3-polymer paint composites. The above observations indicate that these composites can be utilized as coatings for self-cleaning applications.