Changes In Electrical Conductivity Research Articles

Non-Contact Eddy Current Conductivity Measurements as an Effective Tool for Evaluating Aluminum Alloys in Aircraft

ABSTRACT Aluminum alloys (AAs) are pivotal materials in modern aircraft due to their superior mechanical properties and low weight. The structural integrity of these alloys, crucial for aircraft safety, heavily depends on heat treatment processes that alter their mechanical characteristics. Nondestructive evaluation (NDE) techniques, such as eddy current (EC) conductivity measurements, play a vital role in assessing these alloys throughout their lifecycle. EC methods enable the measurement of electrical conductivity, a structure-sensitive parameter that correlates with mechanical properties affected by heat treatments and operational stresses. This paper reviews the application of EC conductivity measurements in the aerospace industry, focusing on their role in assessing AA structural integrity. It discusses how EC methods can penetrate non-conductive coatings, crucial for in-service measurements without surface removal. Recent developments include a novel small-size EC probe and signal processing algorithms aimed at enhancing sensitivity to conductivity changes through dielectric coatings, up to 0.5 mm thick, commonly found in aircraft structures. Key findings include analyses of specific electrical conductivity (SEC) changes in AAs due to heat treatment deviations and long-term operational stresses, crucial for predicting residual life and maintaining safety standards. Case studies on aircraft wing skins and helicopter rotor blades demonstrate the practical application of EC conductivity meters in identifying critical damage zones. The methodology proves effective in evaluating localized degradation based on SEC distributions, thereby enhancing maintenance efficiency and aircraft safety. Overall, this research underscores the significance of EC conductivity measurements in advancing NDE practices for AAs in aircraft applications. The methodologies and findings presented aim to improve safety, durability assessment, and maintenance efficiency in the aerospace industry.

Adsorption and sensing properties of TiO2-modified MoSe2 monolayer for SF6 decomposition components based on the first-principles

As crucial components in power systems, SF6 gas-insulated equipment inevitably develops insulation defects and faults over long-term operation, leading to the decomposition of SF6 gas. Therefore, detecting SF6 decomposition components is essential for assessing the operational status of SF6 gas-insulated equipment and ensuring the safe and stable operation of power systems. Based on first principles, the modification mechanism of TiO2 on MoSe2 was explored, and optimal adsorption models for gases SO2, H2S, SOF2, and SO2F2 on this composite material were established. The adsorption characteristics of each system were analyzed through parameters such as adsorption energy, adsorption distance, charge transfer, electron density difference, and density of states, and the sensing properties of the systems were discussed using parameters including changes in frontier molecular orbitals, desorption time, and sensitivity. The results indicate that TiO2–MoSe2 has difficulty capturing SO2F2, but exhibits chemisorption for SO2, H2S, and SOF2 with adsorption energies of −1.25 eV, −0.99 eV, and −3.40 eV, respectively. Upon adsorption of SO2, TiO2–MoSe2 shows a significant change in electrical conductivity, a desorption time of 4.51 s (at 498 K), and a strong sensitivity response. However, the response to H2S is relatively weak, with lower sensitivity. Therefore, this material is suitable for detecting SO2 but not H2S. TiO2–MoSe2 demonstrates a significant response and excellent sensitivity to SOF2; however, the adsorption process lacks repeatability. Therefore, it can be used as a disposable gas sensor or solid adsorbent for SOF2 detection. The results of this study provide theoretical support for the application of MoSe2-based sensors in the monitoring and fault diagnosis of SF6 gas-insulated equipment.

Transient characteristics of ultra-high frequency adjustable multi-pulse gas tungsten welding arc

In response to the shortcomings of traditional Gas Tungsten Arc Welding (GTAW), such as low penetration, slow welding speed, and low production efficiency, an Ultra-High-Frequency Adjustable Multi-Pulse Gas Tungsten Arc Welding (UFMP-GTAW) process is proposed. This process more effectively concentrates the temperature distribution of the welding arc. To characterize the arc morphology and its dynamic changes, high-speed photography captured ten images of the UFMP-GTAW welding arc within one cycle. The arc image processing algorithm proposed in the paper was used to study the arc's variation characteristics over one cycle. This algorithm includes binarization, arc segmentation, and edge detection to obtain arc morphology parameters. The arc symmetry algorithm is used to symmetrize the arc images for Abel inversion, resulting in the emission coefficient distribution. Further calculations provide the temperature distribution, electrical conductivity distribution, and current density distribution of the arc. Analysis reveals that changes in arc temperature, electrical conductivity, and current density lag behind changes in current. The temperature of the arc spreads from the central axis to the surrounding arc space. When high-frequency current variations occur, the heat input generated by the current increase takes time to transfer to the entire arc space. Conversely, if the current suddenly decreases, the heat input rapidly diminishes. However, because heat transfer takes time, the arc space remains relatively stable for a short period, making the ultra-high-frequency arc form more stable.

(Invited) Wearable Pocket-Sized Fully Non-Contact Cardiorespiratory Sensor

Cardiovascular and respiratory diseases have emerged as the leading cause of global mortality over the past decade, encompassing conditions such as atrial fibrillation and chronic obstructive pulmonary disease. Consequently, continuous monitoring plays a crucial role in managing these conditions, as it enables early detection, improves patient survival rates, and alleviates the burden on emergency medical resources. Our research group has developed a wearable pocket-sized fully non-contact cardiorespiratory sensor that utilizes electromagnetic induction technology to measure dynamic changes in electrical conductivity resulting from cardiac contractions and pulmonary volume variations. This enables the continuous acquisition of eddy current damping response signals to achieve cardiorespiratory monitoring. In comparison to commercially available ECGs, PPG smartwatches, and respiratory sensors, our proposed pocket-sized sensor offers three major advantages: exceptional concealment, convenience, and comfort for health monitoring due to its pocket-sized and micro-structured design; simultaneous acquisition of two-dimensional cardiac and respiratory signals, facilitating comprehensive cardiorespiratory health monitoring; and the ability to adjust sensing depth through frequency modulation of the electromagnetic field, thus eliminating variations in physiological structures among subjects and achieving optimized sensing and personalized medical benefits.

Photo-Modulation of Atomically Thin Molybdenum Diselenides Functionalized with Photochromic Molecules

Two-dimensional (2D) transition metal dichalcogenide semiconductors have garnered significant attention due to their extraordinary electrical and optical properties. It has been increasingly important to develop strategies for modulating their properties. A number of methods have been introduced, including doping, electric and magnetic fields, mechanical strain, etc. Herein, we report a novel approach of using photochromic molecules to modulate optoelectronic properties of monolayer MoSe2 with light. We have synthesized photochromic diarylethene (DAE) molecules that can switch between two isomeric forms, referred to as open and closed, under UV and visible light, respectively. The DAE molecules formed a uniform layer with a thickness of approximately 2 nm on monolayer MoSe2. Our density functional theory (DFT) calculations suggest that the TMD and DAE will align their band energy levels such that UV irradiation moves the lowest unoccupied molecular orbital (LUMO) energy of DAE in between the conduction band minimum (CBM) and valence band minimum (VBM) of MoSe2. This will facilitate photoexcited electron transfer from MoSe2 to DAE LUMO. Experimentally, we have confirmed our predictions by observing a strong quenching of photoluminescence (PL) and an increase of electrical conductivity in MoSe2. In contrast, visible light induced isomerization to the open form of DAE and expanded its energy levels, moving the LUMO level above the MoSe2 CBM. Therefore, the PL was retained and there was no significant change in electrical conductivity. We showed that this photoswitching can dynamically modulate the optoelectronic properties by demonstrating multiple cycles of PL emission and quenching, by alternating UV and visible light repeatedly. Lastly, our Kelvin probe force microscopy (KPFM) revealed that the potential of MoSe2 monolayers can also be modulated with photochromic molecules and external light irradiation. Our work elucidates photo-processes and exciton mechanisms at the hybrid interfaces and lays the foundation for novel applications including new phototransistors and other 2D optoelectronic devices.

Investigation of the structural and microstructural properties of copper and tantalum substituted BiMeVOx compounds with enhanced oxygen ion conductivity: Bi4V2-xCux/2Tax/2O11-3x/4 (0.1≤ x ≤ 0.5)

In this study, the objective was to improve the performance of bismuth vanadium oxide Bi4V2O11 by synthesizing double substituted compounds using copper ions Cu2+ and tantalum ions Ta5+. Bi4V2-xCux/2Tax/2O11-3x/4 (0.1 ≤ x ≤ 0.5) polycrystalline samples of were prepared via the solid-state route. XRD patterns measured at room temperature revealed the stabilization of the monoclinic α-Bi4V2O11 type structure for x = 0.1 and the tetragonal γ or γ' -Bi4V2O11 for x > 0.2. This result has been confirmed by thermogravimetric analysis (DTA), FT-IR spectroscopy and Raman scattering measurements. The influence of the composition on the microstructure and grain size of the prepared samples was explored through dilatometric study, density measurements, and scanning electron microscopy (SEM). Thermal Raman spectra evolution was also investigated. The temperature-dependent Raman spectroscopy analysis of the compound α-BiCuTaVOx (x = 0.1) demonstrated variations in the position, intensity, and width of the Raman mode around 850 cm−1, indicating temperature-assisted structural modifications. One defining feature of the tetragonal-dominated phase of the BiMeVOx systems is the increasing merging of the weak band at 930 cm−1 with the dominating band at 850 cm−1. This behavior was also observed for our samples. The V–O bond lengths were calculated using an empirical relation based on the diatomic approximation. Electrochemical impedance spectroscopy (EIS) was used to investigate the changes in electrical conductivity with the substitution rate across the temperature range of 300–720 °C. The sample with x = 0.3 exhibited the highest electrical conductivity at both high and low temperatures. However, the optimal substitution rate to achieve the best conductivity in this series of copper and tantalum-substituted BiCuTaVOx was found to be x = 0.3 (σ = 4 × 10−3 S cm−1 at 600 °C).

Fabricating Large-Area Thin Films of 2D Conductive Metal-Organic Frameworks.

ConspectusRecent years have witnessed significant interest in two-dimensional metal-organic frameworks (MOFs) due to their unique properties and promising applications across various fields. These materials offer distinct advantages, including high porosity and excellent charge transport properties. Their tunability allows precise control over various factors, including the electronic structure adjustments and local reactivity modulation, facilitating a wide range of properties and applications, such as material sensing and spin dynamics control. Moreover, the precise crystal structure of 2D MOFs supports rational design and mechanism studies, providing insights into their potential applications and enhancing their utility in various scientific and technological endeavors.To fully unveil the latent capabilities of 2D MOFs and advance their applications across diverse fields, thin film synthesis is crucial. Thin films provide a platform for investigating the intrinsic electrical properties of 2D MOFs with anisotropic structures, enabling the exploration of their unique characteristics comprehensively. Additionally, thin films offer the advantage of minimizing interference at contacts and junctions, thereby enhancing the performance of 2D MOFs for various applications. Furthermore, the properties of thin films can vary with thickness, presenting an opportunity to tailor their characteristics based on specific requirements.In this Account, we present an overview of our research focusing on the synthesis of 2D conductive MOF thin films encompassing two primary methods: chemical vapor deposition and solution processing. The chemical vapor deposition method allows for one-step, all-vapor-phase processes resulting in MOFs with edge-on orientation, controllable film thicknesses ranging from 55 to 662.7 nm, and smooth, homogeneous surfaces. On the other hand, solution-processing introduces a novel MOF, Cu3(HHTATP)2, by reducing interlayer interactions through the addition of pendent Brønsted bases on a ligand, enabling spin coating for thin film synthesis. This method yields a concentrated 2D MOF solution, enabling spin coating for thin film synthesis, where reversible electrical conductivity changes occur through doping with an acid and dedoping with a base. Additionally, we discuss various other synthesis methods, such as interfacial synthesis, layer-by-layer assembly, and microfluidic-assisted synthesis, offering versatile approaches for fabricating large-area thin films with tailored properties. Finally, we address ongoing challenges and potential strategies for further advancement in 2D conductive MOF thin film synthesis. We hope that this Account provides insights for selecting synthesis methods tailored to specific purposes, contributes to the development of varied synthesis techniques, and facilitates the exploration of diverse applications, unlocking the full potential of 2D conductive MOFs for next-generation technologies.

Examining the impact of anisotropic particle orientation in a polymer matrix on the electrical properties of composite materials

A number of works have experimentally shown the significant influence of mechanical stretching on the electrically conductive properties of composite polymer materials. Thus, stretching polymer composite films and filaments can lead to deterioration in electrical conductivity properties which can significantly affect the characteristics of products made from such materials. The research conducted in this study focuses on simulation the impact of anisotropic particle orientation within a polymer matrix and mechanical stretching on the electrical properties of composite materials. Based on the Boltzmann statistics, an expression was obtained that allows predicting the change in electrical conductivity during the stretching of polymer composite samples. The Monte Carlo method was used to simulate the destruction of a percolation chain of conductive particles during stretching.

Chemisorption of hydrogen on metal oxides with palladium (II) oxide additives

Chemisorption can lead to a change in electrical conductivity, which allows using semiconductor materials to create gas sensors. On the other hand, semiconductor sensors can be used as devices for studying the chemisorption of gases. In this work, we set two tasks. The first of them was to create a sensor for the selective determination of hydrogen in air, including in a mixture with other gases. The second task was to determine the mechanism of hydrogen chemisorption on the surface of metal oxides with palladium (II) oxide additives. We obtained and characterised nanodispersed materials based on SnO2 and WO3 with additions of 3% PdO by weight. We compared the electrical characteristics of these materials in stationary temperature conditions as well as with temperature modulation in the presence of hydrogen, methane, and their mixtures. The specific features of hydrogen chemisorption were determined on the surface of metal oxide semiconductors based on SnO2 and WO3 with PdO additives in the temperature modulation mode of the sensor. It was shown that the extrema in the dependence of the sensor’s electrical conductivity on temperature can be explained by the contribution of proton transfer to the total electrical conductivity. The presence of extrema in the electrical conductivity of sensors, which were observed in thermal modulation mode in the presence of hydrogen, allows conducting qualitative and quantitative analysis of not only single-component gas systems, but also of mixtures of hydrogen with other analyte gases. In particular, this work demonstrated that it was possible to determine the composition of a hydrogen-methane mixture in air using a single metal oxide sensor. The advantage of this approach is that multidimensional data arrays can be easily processed.

Effect of hollow glass microspheres (HGM) on improving self-heating capability of cement composites exposed to various deterioration conditions

Cement-based self-heating composites play a crucial role in addressing the need for intelligent road and pavement systems capable of efficient de-icing in severe weather conditions. However, the self-heating capability of these composites can be adversely affected by various deteriorating factors such as water ingress, nitric and sulfuric attacks, and freeze-thaw conditions. In this study, we propose the use of hollow glass microspheres (HGM) to enhance the self-heating capability of cement composites exposed to such deteriorating conditions. The initial investigation focused on observing the effects of HGM incorporation on changes in compressive strength, electrical conductivity, and thermal conductivity. Subsequently, the self-heating capability of these composites was systematically examined under cyclic heating conditions following exposure to deterioration factors. Microstructural analysis, including mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM), was conducted. The results indicated that the inclusion of HGM can effectively safeguard the conductive networks from external solutions, thereby preventing potential disconnection of these networks. Consequently, the incorporation of HGM is anticipated to enhance both the electrical stability and self-heating capability of cement composites exposed to diverse deteriorating conditions.

Propolis extract and Hermetia illucens larval proteins synergistically inhibit the growth of Aspergillus niger

The individual and combined inhibitory activities of propolis extract (PE) and Hermetia illucens larval proteins (Black soldier fly larvae proteins) (BSFLP) against Aspergillus niger were investigated. The antifungal effects of PE, BSFLP and Synergy of PE and BSFLP (SPB) against Aspergillus niger were determined by mycelial growth, spore germination rate and hyphal elongation. Membrane integrity was measured by assessing changes in extracellular proteins, reducing sugars, and electrical conductivity. Intracellular MDA, H2O2, ergosterol, and mannan contents were also evaluated. SEM was used to observe the morphology of the Aspergillus niger mycelium. Additionally, AutoDock Tools software and multi-ligand docking methods were used to study the synergistic interactions of ligand combinations on the receptor. The results showed that the combination of PE and BSFLP had excellent effects. During the treatment of antifungal agents, the membrane permeability changed and a large amount of content leaked, while control check (CK) remained almost unchanged. Ergosterol content was found to increase, while mannan content decreased significantly, leading to cell death. In addition, SPB can cause abnormal accumulation of MDA and H2O2, leading to oxidative stress in cells. SEM results showed that morphology of Aspergillus niger treated with SPB was severe wrinkling, distortion and even breakage. Multi-ligand docking results showed that the binding affinity of receptor 1KS5 to 14 complex ligands increased, as indicated by the decrease in docking energy values. These results provide scientific basis for further study on the application of SPB and development of effective antifungal products.

Molecular dynamics simulation, spectroscopy characterization and properties testing of high-titanium CaO-SiO2-10 wt%MgO-13 wt%Al2O3-4 wt%FeO-40 wt%TiO2 slag melts

In this study, the effect of the CaO/SiO2 mass ratio on the viscosity, free running temperature, electrical conductivity and structure of high-titanium CaO-SiO2-10 wt%MgO-13 wt%Al2O3-4 wt%FeO-40 wt%TiO2 slag was investigated. The results revealed that viscosity and free running temperature monotonically decreased with an increasing CaO/SiO2 ratio from 0.1 to 0.8, whereas the electrical conductivity followed a trend of first increasing, then decreasing, and ultimately increasing again. XRD analysis revealed only a small amount of Ti-related phases in the quenched slag. This ensured that the high-temperature state structure of the slag was largely preserved. Molecular dynamics simulations, FTIR, and Raman results indicated that Ti-based structural units predominated in the slag. With an increasing CaO/SiO2 ratio, the [SiO4] tetrahedral and Ti-based structures progressively simplified, while the [AlO4] tetrahedral and Si-O-Al structures showed a tendency of complexity followed by simplicity. However, the overall degree of polymerization of the slag decreased, leading to the viscosity reduction. The degree of polymerization and the migration capacity of ions and electrons together contributed to complex changes in electrical conductivity. A comprehensive analysis indicated that the slag composition with a CaO/SiO2 mass ratio of 0.4 is more favorable for the smelting of vanadium-titanium magnetite in the pre-reduction electric furnace process.

Influence of Polypyrrole on Phosphorus- and TiO2-Based Anode Nanomaterials for Li-Ion Batteries.

Phosphorus (P) and TiO2 have been extensively studied as anode materials for lithium-ion batteries (LIBs) due to their high specific capacities. However, P is limited by low electrical conductivity and significant volume changes during charge and discharge cycles, while TiO2 is hindered by low electrical conductivity and slow Li-ion diffusion. To address these issues, we synthesized organic-inorganic hybrid anode materials of P-polypyrrole (PPy) and TiO2-PPy, through in situ polymerization of pyrrole monomer in the presence of the nanoscale inorganic materials. These hybrid anode materials showed higher cycling stability and capacity compared to pure P and TiO2. The enhancements are attributed to the electrical conductivity and flexibility of PPy polymers, which improve the conductivity of the anode materials and effectively buffer volume changes to sustain structural integrity during the charge and discharge processes. Additionally, PPy can undergo polymerization to form multi-component composites for anode materials. In this study, we successfully synthesized a ternary composite anode material, P-TiO2-PPy, achieving a capacity of up to 1763 mAh/g over 1000 cycles.

PIEZORESISTIVE SENSORS BASED ON PVDF-HFP REINFORCED WITH GNPs FOR HEALTH MONITORING APPLICATIONS

Wearable technology has become increasingly popular in recent years. Wearable sensors are systems made of flexible substrates which good adaptability to human motion monitoring. In parituclar, they allow doctors to obtain real-time data from patients by detecting small changes in baseline values over time, such as the movement of various joints or muscles, heart activity, breathing, and even sweat. In this regard, polymers can offer good flexibility, stretchability, and long-term reliability, which, together with the possibility of modifying their electrical response with conductive nanofillers, makes them promising for the fabrication of this kind of sensors, as their electrical conductivity changes with applied strain. In this work, piezoresistive sensors based on poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) reinforced with graphene nanoplatelets via solvent casting are presented. Here, both the electrical and electromechanical responses are evaluated as a function of different processing conditions, more specifically, sonication time and evaporation temperature. Then, several successful proof-of-concept tests have been carried out from human motion monitoting to pressure sensing applications, with very high sensitivities, being very promising for this kind of applications.

ІТЕРАЦІЙНИЙ МЕТОД ВИЗНАЧЕННЯ ПАРАМЕТРІВ ПЕРЕТВОРЮВАЧІВ ДИФЕРЕНЦІЙНИХ КОНДУКТОМЕТРИЧНИХ СЕНСОРІВ

The proposed method is a development of the well-known one, based on the determination of the sensor's transducers impedance parameters according to the three-element equivalent circuit at two frequencies. The increase in accuracy is achieved due to the step-by-step refinement of parameter values using the values obtained in the previous step using simplified mathematical expressions. Mathematical expressions for calculating the specified parameters are presented. Comparative results of calculations based on known and proposed methods using a computer model are presented, which showed the possibility of significantly reducing the influence of changes in the background electrical conductivity of the solution compared to the known method. References 9, figures 2, tables 1.

Assessing the Impact of Brackish Water on Soil Salinization with Time-Lapse Inversion of Electromagnetic Induction Data

Over the last decade, electromagnetic induction (EMI) measurements have been increasingly used for investigating soil salinization caused by the use of brackish or saline water as an irrigation source. EMI measurements proved to be a powerful tool for providing spatial information on the investigated soil because of the correlation between the output geophysical parameter, i.e., the electrical conductivity, to soil moisture and salinity. In addition, their non-invasive nature and their capability to collect a high amount of data over broad areas and in a relatively short time makes these measurements attractive for monitoring flow and transport dynamics, which are otherwise undetectable with conventional measurements. In an experimental field, EMI measurements were collected during the growth season of tomatoes and irrigated with three different irrigation strategies. Time-lapse data were collected over three months in order to visualize changes in electrical conductivity associated with soil salinity. A rigorous time-lapse inversion procedure was set for modeling the soil salinization induced by brackish irrigation water. A clear soil response in terms of an increase in electrical conductivity (EC) in the upper soil layer confirmed the reliability of the geophysical tool to predict soil salinization trends.

Design, Development and Application of a Modular Electromagnetic Induction (EMI) Sensor for Near-Surface Geophysical Surveys.

Low-frequency electromagnetic induction (EMI) is a non-invasive geophysical method that is based on the induction of electromagnetic (EM) waves into the subsurface to quantify changes in electrical conductivity. In this study, we present an open (design details and software are accessible) and modular system for the collection of EMI data. The instrument proposed allows for the separations between the transmitter to be adjusted and up to four receiving antennas as well as the acquisition frequency (in the range between 3 and 50 kHz) to permit measurements with variable depth of investigation. The sensor provides access to raw data and the software described in this study allows control of the signal processing chain. The design specifications permit apparent conductivity measurements in the range of between 1 mS/m and 1000 mS/m, with a resolution of 1.0 mS/m and with a sampling rate of up to 10 samples per second. The sensor allows for a synchronous acquisition of a time stamp and a location stamp for each data sample. The sensor has a mass of less than 5 kg, is portable and suitable for one-person operation, provides 4 h of operation time on one battery charge, and provides sufficient rigidity for practical field operations.

Исследование закономерностей изменения солевого состава буровых шламов в процессе их утилизации

Drill cuttings in their natural state have viscous-plastic properties; in a dry state they are cohesive and hard. This is due to the content of sodium ions in the absorbing complex. Features of the physical and mechanical properties of drill cuttings indicate its ability to absorb and retain dissolved salts. When gypsum is added to drill cuttings in different percentages of the waste volume, the concentration of chloride ion changes in all samples, and chloride-sulfate salinization is observed. The content of sulfate ion increases with a minimum volume fraction of gypsum application. The addition of gypsum in a volume fraction of 15 and 20% affects the reduction of phosphate and carbonate ions. A change in electrical conductivity indicates an increase in the concentration of water-soluble salts in the water extract, which is confirmed by a direct high correlation. When adding gypsum from 7–20% volume fractions, a significant reduction in the dense residue occurs. The use of gypsum increases the filtration capacity of drill cuttings. The use of gypsum makes it possible to lighten the granulometric composition of drill cuttings due to the active coagulation of colloids. As a result of the removal of water-soluble salts, optimal water-physical properties of drill cuttings are created, structuring and filtration properties of drill cuttings are increased. A mathematical model for predicting the dissolution of salts in drill cuttings allows taking into account uncontrollable factors (density, particle size distribution, filtration coefficient, content of water-soluble salts).

TREATMENT OF INDUSTRIAL WASTEWATER BY USING ECO-FRIENDLY TECHNIQUE

The textile industry is one of the major industries and work as the backbone of economy of Pakistan. It employs thousands of people without any education. It plays important role in the economy of every country around the world. The textile industry has high importance when it comes to the environment because it consumes many environmental resources such as water. Also, it produces a large amount of wastewater which is then discharged into the environment and causes environmental pollution. In this study, Ocimum basilicum L. (sweet basil seeds) and Tamarindus indica seeds have been evaluated as an active natural coagulant for the removal of pollutants from textile wastewater. The change in pH, Dissolved Oxygen, Electrical conductivity, TDS, COD, and heavy metals/pollutants were analyzed. Also, the dye concentration was found to be the most important parameter affecting color removal. Pollutant removal efficiency was obtained by using a low number of coagulants. The mucilage of O. basilicum and the powder of T. indica seeds were found to be highly effective in treating textile wastewater as a sole coagulant. The results show that these coagulants help to reduce heavy metals from 0.16 ppm to 0.02 ppm. Utilization of these natural coagulants was found to be suitable, easier, cost-effective, and environment friendly for textile waste water treatment.

In-Plane Sliding Ferroelectricity Realized in Penta-PdSe2/Penta-PtSe2 van der Waals Heterostructure.

Different from conventional 2D sliding ferroelectrics with polarization switchable in the out-of-plane via interlayer sliding, we show the existence of in-plane sliding ferroelectricity in a bilayer of a pentagon-based van der Waals heterostructure formed by vertically stacking an experimentally synthesized penta-PdSe2 sheet and a crystal lattice well-matched penta-PtSe2 sheet. From the 128 sliding patterns, four stable configurations are found that exhibit in-plane sliding ferroelectricity with an ultralow polarization switching barrier of 1.91 meV/atom and a high ferroelectric polarization of ±17.11 × 10-10 C m-1. Following the ferroelectric transition among the stable sliding configurations, significant changes in carrier mobility, electrical conductivity, and second harmonic generation are identified. In particular, the ferroelectric stacking configurations are found to possess a negative Poisson's ratio, facilitating the experimental characterization of the sliding ferroelectric effect. This study demonstrates that pentagonal sheets can be used to realize 2D in-plane sliding ferroelectrics going beyond the existing ones.