Energy Dispersion Research Articles

The impact of pulsed Nd:YAG laser on the surface of n-Si and photo-electrical performance of silicon solar cells

Texturizing the surface of a silicon solar cell enhances performance by reducing reflection losses. Pyramidal texturization via wet chemical etching is standard in manufacturing, while plasma etching is often used for vertical hole texturization. Laser texturization offers a chemical-free, user-friendly alternative to plasma etching. Infrared (IR) transmission studies indicate that laser-textured samples transmit more IR light through n-Si than normally textured samples, suggesting that vertical grooves from laser texturization allow deeper light penetration. Analyses using cross-sectional Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersion x-ray (EDX), and Energy Dispersive Spectroscopy (EDS) demonstrate the effects of laser texturization on the front surface of textured n-Si wafers. However, silicon solar cells with laser-textured surfaces demonstrated lower conversion efficiencies (1.20% to 4.30%) compared to conventionally textured cells (14.30%). The short-circuit current density (JSC) was also lower in laser-textured cells, below 17 mA cm−2, compared to 34.44 mA cm−2 in normally textured cells. At the same time, higher laser power (114 W) during texturization also led to the lowest JSC and open-circuit voltage (VOC), indicating that laser texturization may introduce defects and dislocations that degrade Si properties.

Crystal structures, NCI-RDG, Hirshfeld surface and energy framework analysis of tetra aryl substitute bispidine and oxaquinuclidine core containing derivatives: A potential COVID-19 drug candidate

Two of the title compounds are crystallized in P21/c and monoclinic face groups. Each crystal unit cell has four molecules. There are two piperidine rings: one in the chair conformation and another one in the boat conformation. The piperidine nitrogen in the boat conformation is joined to the oxygen-containing chair conformation piperidine ring to produce the oxaquinuclidine ring (-N-CH2O-). Furthermore, because of the steric barrier between rings, all aryl groups are oriented in an equatorial position. The crystal network is maintained through several interactions, including C—H⋯O/N/Cl/π. The crystal void and interaction energy studies gave additional evidence of the strength of the crystal packing and intermolecular linkage. Crystal 3b has less cavity than crystal 3c, indicating that it is densely packed. The dispersion energy contribution dominates the stability, according to the analysis of the electrostatic, dispersion, and total energy frameworks. Reduced density gradient (RDG), electron localization function (ELF), and localized orbital locator (LOL) analysis were used to determine the molecular interaction, electron pair density, and maximally localized orbitals overlapping sites, respectively. This approach reveals that oxaquinuclidine ring steric hindrance and the electron densities throughout the molecules. Density function theory (DFT) provides more evidence for the ring's orientation and the molecules' reactivity. A molecular docking investigation of four essential COVID-19 proteins was carried out using these theoretical ideas. This investigation demonstrates that each protein's reactivity varies; certain proteins have more interaction with high electron density molecules (electron-donating substituent), while others have more interaction with low electron density molecules (electron-withdrawing substituent). The ADMET and drug-likeness investigations reveal that methoxy group substituted molecules perfectly correlate with the required pharmacological characteristics. The cytotoxicity of the five compounds was assessed using the HEK293T cell.

Influence of chromium concentration on the structural, optical, magnetical, and thermal properties of ZnS nanocrystals

Pure ZnS and Zn1-xCrxS nanoparticles were successfully prepared using the coprecipitation method, where x represents the concentration (x = 0.00, 0.10, and 0.05). There are many analytical methods used, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Spectroscopy of energy dispersive (EDS). The magnetism structure of the catalysts was investigated using spectrophotometry (VSM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). X-ray diffraction studies determine the nanocrystal arrangement and size of microcrystals. As seen in SEM analysis, the particles are agglomerated. The coordination of sulfur ions around zinc ions was examined using FTIR analysis. The energy band gap of the Cr-doped sample increases. Photoluminescence spectroscopy showed that the violet emission around 424 nm could be attributed to the excitation process of electrons from the low energy of the conduction band to the valence band of sulfur intermediate atoms. The front amplitude of doped ZnS nanocrystals remains constant regardless of the amount of Cr present. The results show that the ZnS nanocrystals were replaced by dilute Cr3+ ions. Cr-doped ZnS exhibits diamagnetic properties under hightemperature conditions. The results show that these materials are improved by the Cr doping process, making them suitable for many applications.

Exploring the structural, electronic, mechanical, magnetic and optical properties of Cs-based hydride-perovskites CsXH3 (X = Cr, Mn) for hydrogen storage application

Low cast hydride-perovskites are more efficient in power conversion and for energy storage. Here in, structural investigation, electronic, mechanical and optical properties of hydrogen based CsXH3 (X = Cr, Mn) compounds using the density functional theory. The result shows that both materials crystallize into cubic structure. The thermodynamic and dynamic stabilities are conformed through formation energy and phonon dispersion curve. The optimized lattice constants are 3.52 Å and 3.54 Å for CsCrH3 and CsMnH3 respectively. Both materials are found to be half metallic in nature. IR-Elast package are used to obtain elastic constants. The elastic study presents that both materials are ductile and have anisotropic nature. The optical parameters are studied in the range of 0–10 eV. The optical results show that both materials have an excellent optical absorption. The values obtained of gravimetric hydrogen storage capacity for these compounds are 1.55 % and 1.58 % for CsMnH3 and CsCrH3 respectively indicating that these materials can be an excellent candidate for hydrogen energy storage.

The “SEP Clock”: A Discussion of First Proton Arrival Times in Wide-Spread Solar Energetic Particle Events

This work analyzes the appearance of wide-spread deka-MeV solar energetic proton (SEP) events, in particular the arrival of the first protons within ≈ 4.5 – 45 MeV measured at Earth–Sun L1, and their relationship with their relative solar source longitude. The definition of “wide-spread SEP event” for this study refers to events that are observed as a 25 MeV proton intensity increase at near 1 AU locations that are separated by at least 130∘ in solar longitude. Many of these events are seen at all three of the spacecraft, STEREO (Solar-Terrestrial Relations Observatory) A, STEREO B, and SOHO (Solar and Heliospheric Observatory), and may therefore extend far beyond 130∘ in longitude around the Sun. A large subset of these events have already been part of a study by Richardson et al. (Solar Phys., 289, 3059, 2014). The event source region identifications draw from this study; more recent events have also been added. Our focus is on answering two specific questions: (1) What is the maximum longitude over which SEP protons show energy dispersion, i.e., a clear sign of arrival of higher-energy protons before those of lower energy? (2) What implications can be drawn from the ensemble of events observed regarding either direct magnetic connectivity to shocks and/or cross-field transport from the site of the eruption in the onset phase of the event?

Influence of HSS drill coatings on surface finish and cylindricity of AA6061/C/ZrO2 composite in CNC drilling operations under dry conditions

Abstract This study aims to evaluate the effect of HSS drill tool coatings, namely single-layer TiN, single-layer AlCrN, and double-layer AlTiN + TiSiXN (Durana), on the surface roughness and cylindricity of AA6061 (90 wt%)/C (5 wt%)/ZrO2 (5 wt%) hybrid composite material processed by the stir casting method. The fabricated sample was examined for the uniform particle distribution of reinforcements using Scanning Electron Microscope. The drilling operation was carried out on the fabricated in a CNC machining center by setting the spindle speeds of 800, 1200, and 1600 rpm, depths of cut of 0.5, 1, and 1.5 mm, and feeds of 50, 100, and 150 mm/rev. An orthogonal array (L27) designed by Taguchi’s method was used as the design of the experiment for the optimization of the best cutting parameters and coating. Surface roughness and cylindricity errors were determined for the 27 experimental runs. Field emission scanning electron microscopic (FESEM) examination and Energy Dispersive Spectroscopy (EDS) were used to analyze the surface integrity and elemental composition, respectively. The results revealed that Durana had a significant effect on the surface substrate with minimum surface roughness (Ra) of 1.666 μm and obtained the minimum cylindricity error for the parameters of depth of cut 0.5 mm, spindle speed of 1200 and feed of 100 mm rev−1.

Application of the luminous bacterium Photobacterium phosphoreum for toxicity monitoring of selenite and its reduction to selenium(0) nanoparticles

Luminous marine bacteria are traditionally used as a bioassay due to the convenience and high rate of registering the intensity of their physiological function – luminescence. This study aimed to develop the application of Photobacterium phosphoreum in traditional and novel fields – toxicity monitoring and biotechnology. We demonstrated (1) effects of selenite ions on bioluminescence, and (2) biotransformation of selenite to selenium(0) in the form of nanoparticles. The effects of selenite (SeO32−) on the intensity of bacterial bioluminescence were studied, and its dependencies on exposure time and concentration of Na2SeO3 were analyzed. Bioluminescence activation and inhibition were revealed; dose–effect dependencies corresponded to the hormesis model. The toxicity of SeO32− was characterized by an effective concentration of 10−3 M. Effects of SeO32− on reactive oxygen species (ROS) in bacterial suspensions were studied. High positive correlations were found between the bioluminescence intensity and ROS content, which indicates the decisive role of ROS and associated redox processes in the bioeffects of selenite ions. Scanning and transmission electron microscopy revealed the presence of nano-structures in the bacteria exposed to selenite. The energy dispersion spectrum detected a high content of selenium in the nanoparticles. The particle size distribution depended on Na2SeO3 concentration; maxima of the distribution varied within 45–55 nm.

Exploring the Multifunctional aspects of SrBi2-X(CoFe2O4)XNb2O9 Nanocomposite Materials Emphasizing the Structural, Elastic, and Optical Properties

Nanocomposites of SrBi(2-X)(CF)XNb2O9 (SBNCF) (CF=CoFe2O4 for X = 0.0 to 0.5 with a step increment of 0.1) were synthesized using the hydrothermal method and characterized for their structural, morphological, elastic, and optical properties. The incorporation of CF into SrBi2Nb2O9 (SBN) resulted in hybrid composites with tailored properties. X-ray Diffraction (XRD) with Rietveld refinement analysis confirmed the formation of orthorhombic SBN and spinel CF phases. Field Emission Gun Scanning Electron Microscopy (FEG-SEM) revealed that SBN exhibits a plate-like morphology, with the incorporation of CF into the SBN matrix resulting in both plate-like and octahedral-shaped grains. The Brunauer–Emmett–Teller (BET) method was used to determine the pore radius and surface area, both of which were found to have increased, indicating an enhancement in photocatalytic performance. The presence of the constituent elements in the prepared compositions was confirmed by Energy Dispersive Spectroscopy (EDS). Fourier Transform Infrared Spectroscopy (FTIR) spectra were used to determine elastic properties, suggesting potential applications in electronic noise filtering. From Diffuse Reflectance Spectroscopy (DRS), a recognizable semiconducting behavior and band gap bowing were noticed in SBNCF nanocomposites on the obtained energy band gap values (2.20 eV - 1.56 eV) compared to the SBN host matrix (3.16 eV). The materials exhibited strong emission peaks at 470 nm, 528 nm, 584 nm, and 703 nm upon the excitation of 425 nm light using Photoluminescence (PL) spectroscopy. The white emission was predominant at room temperature in all the produced samples and the corresponding color temperature values range from 5865.93 K to 7599.05 K from the CIE diagram. The SBNCF materials are promising candidates in photocatalytic reactions and white light-emitting diodes (w-LEDs) based on their enhanced optical properties.

Failure Analysis of Bypass Rupture of Flowmeter in Steam Pipeline

Abstract A petrochemical company’s pipeline ruptured in the flowmeter bypass of the main steam pipeline during a steam blowdown before commissioning, resulting in material failure and inoperability. The cause of the pipe rupture needed to be detected experimentally. To study the failure in the steam pipeline of a flowmeter of bypass rupture, visual inspection, mechanical properties testing, chemical composition analysis, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Mechanical property. The experiments confirmed the reason for the bypass rupture of the 15CrMoG steam pipeline: improper heat treatment transforms the material’s structure, and the pearlite spheroidization (PC) leads to the deterioration of the material’s mechanical properties. The main manifestations are as follows: the grains in the superheated zone of the welding exhibit a coarse morphology, and a distinctive superheated Widmanstatten structure is formed due to rapid cooling, resulting in a significant reduction in material plasticity and impact toughness. High-temperature oxidation occurs, accompanied by localized enrichment of Cr-element in certain areas, while other regions experience Cr depletion, resulting in the deterioration of material properties.

Effect of Electromagnetic Field Assistance on the Wear and Corrosion Resistance of Nickel-Based Coating by Laser Cladding

Offshore wind turbine generators usually demand higher requirements for key component materials because of the adverse working environment. Therefore, in this study, electromagnetic-assisted laser cladding technology was introduced to prepare the nickel-based composite coating on the Q345R matrix of wind turbine generator key component material. By means of Scanning Electron Microscope (SEM), X-ray diffraction (XRD), Energy Dispersive Spectrometer (EDS), the Vickers hardness tester, friction and wear tester, and electrochemical workstation, the effects of different magnetic field intensities on the macroscopic morphology, microstructure, phase composition, microhardness, wear resistance, and corrosion resistance of the coating were analyzed. The experimental results show that the addition of a magnetic field can effectively reduce the surface defects, improve the surface morphology, and not change the phase composition of the coating. With the increase in magnetic field intensity, the microstructure is gradually refined, and the average microhardness increases gradually, reaching a maximum of 944HV0.5 at 8 T. The wear resistance gradually increases with the increase in magnetic field intensity, especially when the magnetic field intensity reaches 12 T, the wear rate of the coating is reduced by 81.13%, and the corrosion current density is reduced by 43.7% compared with the coating without a magnetic field. The addition of an electromagnetic field can enhance the wear resistance and corrosion resistance of the nickel-based laser cladding layer.

Eco-Friendly Electrochemical Sensor for Accurate Soil Nitrate Detection using ZnOx/PANI Nanocomposite on Nickel Foam Electrode

This study presents an innovative approach to enhancing nitrate detection in soil, a critical macronutrient for agriculture. We developed a novel electrochemical sensor using a nanocomposite of Zinc Oxide (ZnOx) and Polyaniline (PANI) on a Nickel foam electrode. The nanocomposite was synthesized through cyclic voltammetry and characterized using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD) to analyze its morphological, elemental, and crystalline properties. The sensor's performance was evaluated using square wave voltammetry, revealing a direct linear relationship between the peak current and nitrate concentration. The sensor demonstrated high sensitivity (4.53 µA/µM) and a low detection limit (0.40 µM), confirming its potential for precise and sensitive nitrate analysis in soil samples.

Unravelling the importance of hydrogen bonds and dihydrogen interactions in the supramolecular assembly of a caryolan-1-ol derivative: an experimental and theoretical investigation

We report here the synthesis of a caryolan-1-ol derivative, namely [(1R, 2S, 5R, 8S)-1-hydroxy-4,4,8-trimethyltricyclo[6.3.1.02,5]dodecan-6-one] (3), characterized by structural single-crystal X-ray diffraction, FTIR and 1H and 13C NMR spectroscopies. The crystal structure reveals weak noncovalent interactions along with O-H···O hydrogen bonding interactions that forms 1D network architectures. Hirshfeld surfaces and their two-dimensional fingerprint plots allow us to visualize the intermolecular contacts and their relative contributions to the total Hirshfeld surface for the compound. A comparative analysis against related compounds was carried out. The interaction energies for the molecular pair involving O-H···O hydrogen bonds indicated a dominant contribution to packing stabilization coming from the Coulombic components. Energy framework calculations afforded to analyse and visualize the topology of the intermolecular interactions responsible for the crystal packing, showing that dispersion energy prevail over the electrostatic one in the structure of 3. Theoretical calculations have been performed to analyse the unconventional noncovalent interactions observed in the solid-state structure of 3 using the quantum theory of atoms in molecules (QTAIM), noncovalent interactions plot (NCIplot) and natural bond orbital (NBO) computational tools.

Powder metallurgical processing of novel Al0.5CoCrFeNiNb0.5-Si0.1 high entropy alloys: Phase evolution and nanomechanical properties

In this research, the high entropy alloy (HEA) of Al0.5CoCrFeNiNb0.5-Si0.1 was successfully synthesized through mechanical alloying utilizing a high-energy planetary ball mill. The synthesized HEA powder was subsequently pressed and sintered at 1400 °C with varying holding times. The phase evolution was investigated using X-Ray Diffraction (XRD) technique. Furthermore, the microstructural, morphological, and compositional characteristics of the powders were examined using Transmission Electron Microscopy (TEM) with Selected Area Electron Diffraction (SAED), as well as Scanning Electron Microscopy (SEM) in conjunction with Energy Dispersive Spectroscopy (EDS). The nano-mechanical properties of the HEA compact were evaluated through nanoindentation to determine nano-hardness and elastic modulus.The mechanical alloying process was conducted for a duration of 30 h, resulting in the formation of a single-phase BCC solid solution, as confirmed by XRD and SAED analyses. The study investigated the criteria for phase stability based on the minimum Gibbs free energy and Hume-Rothery rules, which were consistent with the observed microstructural characteristics. Furthermore, the sintering process resulted in porosity levels of 6.01 % and 4.71 %, with corresponding densities of 6.96 g/cm³ and 7.12 g/cm³ for holding times of 3 and 4 h, respectively. It was noted that extended holding times improved the mechanical properties, with the alloy achieving a maximum hardness of 546 HV, nano-hardness of 5.57 GPa, elastic modulus of 265.47 GPa, and yield stress of 1.89 GPa after a holding time of 4 h.

PHYSICOCHEMICAL CHARACTERISATION OF SUVARNA BHASMA AND SUVARNA PRASHA USING ADVANCED TECHNIQUES

Background: Suvarna Prashana is an ancient Indian practice that boosts immunity, intelligence, memory, complexion, and virility and prevents infections in children. However, the characterisation of the drug is very limited. Material and Method: In this study, the physicochemical characterisation of Suvarna Bhasma is done with Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive Xray Analysis (EDAX ), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Suvarna Prash containing 15 mg of Suvarna Bhasma mixed with 0.25 ml of ghee and 0.75 ml of honey is characterised with Fourier Transform Infrared Spectroscopy (FTIR) with Suvarna Bhasma. Results: SEM revealed that gold particles of Suvarna Bhasma ranged from 27 nm - 8.1 µm and formed spherical aggregates of varied sizes with rough surfaces. EDAX suggested that Suvarna Bhasma contained Gold (86.3%), Oxygen (3.14%), and Carbon (10.52%). TEM reported that the particle size ranged from 2.2 to 18.9 nm, which existed in polycrystalline form as suggested by XRD. XPS confirmed the elemental state of gold Au(0), Silver-Ag +oxidation state, Carbon C-C, C=O, and C-N, where carbon is bonding with carbon, oxygen and nitrogen. FTIR revealed that Suvarna Bhasma alone had a single functional group of alkynes. When Suvarna Bhasma was triturated with honey and ghee, many functional groups were added to Suvarna Bhasma, i.e. fats, carbohydrates and amino acids. Conclusion: In this novel study, FTIR of Suvarna Prasha is reported for the first time, and it can be used as a fingerprint for drug identification. Also, it proves that Suvarna Bhasma, used in the current study, is a pure form of gold without heavy metals like mercury.

Surface Thermodynamic Properties of Styrene–Divinylbenzene Copolymer Modified by Supramolecular Structure of Melamine Using Inverse Gas Chromatography

The surface thermodynamic properties of polymers and copolymers modified by supramolecular structures are used in several industrial processes, such as selective adsorption, paints, coatings, colloids, and adhesion applications. Background: Inverse gas chromatography at infinite dilution was proved to be the best technique to determine the surface properties of solid surfaces by studying the adsorption of some model polar and non-polar organic molecules adsorbed on solid surfaces at different temperatures. Methods: The retention volume of adsorbed solvents is a valuable parameter that was used to obtain the London dispersive and polar free energies and the London dispersive surface energy of styrene–divinylbenzene copolymer modified by supramolecular structure of melamine using both the Hamieh thermal model and our new methodology consisting of the separation of the two polar molecules and the dispersive free energy of their interaction. This led to the determination of the polar acid and base surface energy, and the Lewis acid–base constants of the various solid materials. Results: Following our new methodology, all surface energetic properties of styrene–divinylbenzene copolymer modified by melamine at different percentages were determined as a function of temperature. Conclusions: It was observed that the styrene–divinylbenzene copolymer exhibited the highest London dispersive surface energy, which decreased when the melamine percentage increased. All materials presented higher Lewis basicity and this Lewis basicity increased with the percentage of melamine.

First-Principles insights to probe structural and opto-electronic properties of [formula omitted] (Y=Mg, Sr) halide perovskites with variety of DFT methods

This study reports the structural, electronic, optical, phonon, thermodynamic and thermoelectric properties of AgYF3 (X=Mg, Sr) for photovoltaic and energy applications. We performed first principles calculations using full potential linearized augmented plane wave, FP-LAPW method implemented in Wien2k. The generalized gradient approximations of Perdew–Burke–Ernzerhof PBE-GGA, and PBE revised for solids, PBEsol, is employed for structural optimization of these lead free halide perovskites. The Birch–Murnaghan energy volume curve fitting comprehend the structural stability. The optimized lattice constant of AgMgF3 and AgSrF3 obtained with PBE-GGA(PBEsol) is 3.99(3.92)Å and 4.42(4.65)Å. The stability is further tested with the help of formation energy and positive phonon dispersion curves calculations. For the calculations of explicit electronic and optical properties, we also employed Tran–Blaha modified Beck–Johnson (TB-mBJ) and Strongly Constrained but Appropriately Normed, SCAN, exchange and correlations functionals. The electronic band gap of AgMgF3 computed with PBEsol, TB-mBJ and SCAN is 1.96 eV, 5.25 eV and 2.59 eV exhibiting M-Γ indirect band gap. The band gap energy of AgSrF3 is 2.06 eV, 6.42 eV and 2.70 eV with PBEsol, TB-mBJ and SCAN. The indirect band gap nature of AgSrF3 is confirmed by PBEsol and TB-mBJ while it anticipated direct band gap behavior with meta-GGA SCAN. The different optical parameters like dielectric constant, optical conductivity, energy loss function, absorption, reflectivity and refractive index are calculated to assess optical activity of both perovskites. Comprehensive electronic and optical analysis advocates the utility of AgMgF3 and AgSrF3 for different applications is solar technology and optoelectronic devices.

A stochastic averaging mathematical framework for design and optimization of nonlinear energy harvesters with several electrical DOFs

Energy harvesters for mechanical vibrations are electro-mechanical systems designed to capture ambient dispersed kinetic energy, and to convert it into usable electrical power. The random nature of mechanical vibrations, combined with the intrinsic non-linearity of the harvester, implies that long, time domain Monte-Carlo simulations are required to assess the device performance, making the analysis burdensome when a large parameter space must be explored. Therefore a simplified, albeit approximate, semi-analytical analysis technique is of paramount importance. In this work we present a methodology for the analysis and design of nonlinear piezoelectric energy harvesters for random mechanical vibrations. The methodology is based on the combined application of model order reduction, to project the dynamics onto a lower dimensional space, and of stochastic averaging, to calculate the stationary probability density function of the reduced variables. The probability distribution is used to calculate expectations of the most relevant quantities, like output voltage, harvested power and power efficiency. Based on our previous works, we consider an energy harvester with a matching network, interposed between the harvester and the load, that reduces the impedance mismatch between the two stages. The methodology is applied to the optimization of the matching network, allowing to maximize the global harvested power and the conversion efficiency. We show that the proposed methodology gives accurate predictions of the harvester’s performance, and that it can be used to significantly simplify the analysis, design and optimization of the device.

Optimization Photodegradation of Methylene Blue Dye using Bentonite/PDA/Fe3O4@CuO Composite by Response Surface Methodology

This study aims to synthesize bentonite/PDA/Fe3O4@CuO composites as a catalyst for the photodegradation of Methylene blue dye. Composite characterization involves X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) with X-ray Energy Dispersion Spectrometry (EDS), UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS), and Vibrating Sample Magnetometer (VSM). Response Surface Methodology (RSM) employs Central Composite Design (CCD) to optimize photodegradation by varying dye concentration, irradiation time, and catalyst dose. The bentonite/PDA/Fe3O4@CuO composites exhibit a saturation magnetization value of 54.82 emu/g and a band gap of 2.1 eV. The optimization revealed that concentration and dose significantly impact the photodegradation efficiency. A quadratic model is suitable for modeling the photodegradation of Methylene blue dye using bentonite/PDA/Fe3O4@CuO composites, as determined by analysis of variance (ANOVA). The optimal conditions for achieving maximum photodegradation efficiency were identified as a dye concentration of 10 mg/L, an exposure time of 90 min, and a catalyst dose of 1.67 g/L. Under these parameters, the photodegradation process exhibited a remarkable efficiency of 100%. The Bentonite/PDA/Fe3O4@CuO composites exhibited strong stability, efficiency, and recyclability. After six photodegradation cycles, there was a 5.18% decrease in photodegradation efficiency. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Investigation on utilization and microstructure of fine iron tailing slag in road subbase construction

The iron tailing slag is solid waste produced during the iron ore refining process and is considered a potential hydraulic material that can be used in road construction. This study focused on fine iron tailing from a location in Hebei, China, to prepare road subbase specimen with a high proportion of fine iron tailing. The research investigated the effects of raw material ratios and additives on the 7-day unconfined compressive strength and elastic modulus of the specimens, as well as their mechanisms of action. A series of single-factor experiments were conducted using a controlled variable approach, including the mass ratio of slag to fly ash (SFR), cement content, and calcium oxide content. It was found that under the conditions of an SFR of 6:1, a calcium oxide content of 4 %, a cement content of 5 %, and a water-resistant base stabilizer additive of 0.02 %, the eco-friendly road subbase specimen achieved a 7-day unconfined compressive strength of 1.97 MPa and an elastic modulus of 286 MPa, demonstrating good mechanical properties. Additionally, a linear relationship was observed between the cement content and the 7-day unconfined compressive strength of the specimen: Rc = 0.253w + 0.793. Using characterization techniques such as X-ray Fluorescence Spectroscopy (XRF), X-Ray diffraction (XRD), Scanning Electron Microscope & Energy Dispersive Spectroscopy (SEM-EDS), and Fourier Transform Infrared Spectroscopy (FTIR), a dense structure was observed in the slag-based road subbase specimen, composed of needle-rod hydrated calcium silicate (C-S-H) gel, hydrated calcium aluminate (C-A-H), hydrated calcium silicoaluminate (C-A-S-H), flake-like hydrated magnesium silicate (M-S-H) gel, and a system containing a large amount of Forsterite. Finally, the study examined the impact mechanisms of five additives—Na2CO3, Na2O·2SiO2, triethanolamine (C6H15NO3), CaSO4, and a water-resistant base stabilizer—on the compressive strength and elastic modulus of the slag road base specimen. It was concluded that the water-resistant base stabilizer significantly improved strength and reduced water absorption. The road subbase specimen can be used by simply mixing at room temperature and pressure, offering broad prospects for industrial application. This technology provides a paradigm for the comprehensive utilization of fine iron tailing and the preparation of new road subbase materials.

Cavitation-assisted synthesis and chracterization of a novel catalyst from waste coconut trunk biomass for biodiesel production

In the current study, a novel heterogeneous catalyst has been prepared from waste coconut trunk biomass using an ultrasound-assisted batch reactor. It is observed from the characterization studies that the raw coconut trunk biomass consists of the maximum amount of silicon dioxide (SiO2) present in it which is further converted to mullite (composition of 3Al2O3.2SiO2) with a composition of 94.18 % (analyzed through Energy Dispersive Spectroscopy (EDAX) studies) is formed through the reaction in an ultrasound reactor processed at a very mild reaction temperature and reaction time 80℃ and 90mins. Synthesis of catalyst at mild process conditions will help to enhance the formation of energy-intensive products at a low cost. It is also observed from the XRD studies of raw feedstock and synthesized catalyst a change in the crystalline structure from hexagonal silicon dioxide to orthorhombic mullite shape. In comparison with the surface area of the raw biomass and mullite, a large amount of surface area ∼ 32 m2/g is observed which is due to the process of reaction in a highly intense ultrasound reactor. A change in the morphological structure of raw feedstock and synthesized catalyst is also observed through scanning electron microscope (SEM) analysis. The activity of the synthesized catalyst has been analyzed through its application in the production of biodiesel from waste cooking oil is also studied., and a yield of 75 % with a conversion of 74 % is observed at process conditions of 1:3 (oil: ethanol) (volumetric ratio), 3 (wt%) of catalyst concentration and 3hrs of reaction time. A prospective aspect of the implication of the entire work to analyze the life cycle analysis (LCA) is also reported in terms of environmental friendliness and sustainability.