Surface Morphology Research Articles

Simple and selective detection of trifluralin herbicide in underground waters based on modified silver nanoparticles by 4-mercaptophenylbronic acid

ABSTRACT Due to the increase in agricultural contaminants in tap water and the importance of contaminant detection analysis, we report a sensitive and accurate colorimetric sensor based on the silver nanoparticles (AgNPs) to detect Trifluralin (TFA) in tap water. Silver nanoparticles were modified with 4-mercaptophenylbronic acid (MPBA) and for obtaining better responses from MPBA-AgNPs as a colorimetric sensor, Conditions affecting the reactions were optimised. The surface morphology, chemical structure and size of the MPBA-AgNPs sensor in different conditions were examined by FE-SEM, FT-IR, DLS and TEM analyses. Finally, it was used as a sensor to detect and measure the TFA herbicide with LOD = 3.20 ppm and RSD = %3.30. The recovery was obtained in the range of %87.15–%105.45, which indicated that the presented method is very practical and highly accurate for measuring this herbicide in its real samples.

Non-monotonic dependence of high-temperature stability of stone wool fibres on pre-oxidation time and temperature

Stone wool is a sustainable, fire-safe insulation material, and its fire-safety depends on its high-temperature stability (HTS). It is known that the HTS of stone wool fibres can be enhanced by pre-oxidation (i.e., heat treatment in air) at temperatures below or at its glass transition temperature (Tg). However, so far, a quantitative trend of HTS with varying pre-oxidation temperature (Tpre-ox) and time (tpre-ox) remains unknown. In this study, we quantified the change of HTS of stone wool fibres with a Tg of 677 °C as functions of both Tpre-ox and tpre-ox through a hot-stage microscope. The derived results revealed striking non-monotonic trends in the HTS of stone wool fibres. The HTS first increased with Tpre-ox from 500 to 630 °C for tpre-ox of 15 minutes, but declined beyond 630 °C. The HTS was significantly improved upon pre-oxidation for merely 2 minutes, at 677 °C, then dropped with extending tpre-ox to 16 hours, and finally increased again with tpre-ox up to 16 days. The origin of the non-monotonic trend was explored by characterizing the crystallization behaviour, thermal expansion, surface composition, and surface morphology in stone wool fibres after pre-oxidation.

Enhanced Triethylamine Detection at Room Temperature Using a Layered MoS2 Nanosheet-Coated PPy Nanorod: A Comprehensive Study.

The rapid and reliable detection of triethylamine (TEA), a toxic, explosive, volatile organic compound at room temperature, is highly significant for food safety, environmental, and human health monitoring. This manuscript reports a layered molybdenum disulfide (MoS2) nanosheet-coated polypyrrole (PPy) nanorod-based heterostructure sensor (MsPy) which offers superior sensing properties toward TEA at room temperature (25 °C). Herein, different MsPy nanocomposites were synthesized, followed by a controlled sulfidation reaction through dissolution, diffusion, and regrowth mechanisms. Optimizing the ratio of the precursor of molybdenum trioxide (MoO3/PPy) is crucial for achieving effective deposition of a layered MoS2 nanosheet on the PPy surface. The as-prepared MoS2 nanosheet-coated PPy sensor (MsPy_40) enables one to selectively detect trace TEA vapor at 25 °C with a detection lower limit of 0.5 ppm. The MsPy_40 sensor exhibits 17 times higher response than the pristine MoS2 nanosheet to 50 ppm TEA, with rapid response (∼3.9 s) and recovery (∼19.6 s), along with better stability, good selectivity, and remarkable repeatability. The significantly enhanced sensing performance is attributed to the unique surface morphology of the layered MoS2 nanosheet-coated PPy nanorod and the formation of a p-n heterojunction between PPy and MoS2.

Research on the corrosion inhibition performance and mechanism of pyrimidine quaternary ammonium salt

Purpose At present, research on the preparation of corrosion inhibitors using modified pyrimidine derivatives is still blank. The purpose of this study is to synthesize a new cationic mercaptopyrimidine derivative quaternary ammonium salt, known as DTEBTAC, that can be used as a corrosion inhibitor to slow down the metal corrosion problems encountered in oil and gas extraction processes. Design/methodology/approach A new corrosion inhibitor was synthesized by the reaction of anti-Markovnikov addition and nucleophilic substitution. The weight loss method was used to study the corrosion inhibition characteristics of synthetic corrosion inhibitors. Electrochemical and surface topography analyses were used to determine the type of inhibitor and the adsorption state formed on the surface of N80 steel. Molecular dynamics simulations and quantum chemistry calculations were used to investigate the synthetic corrosion inhibitor’s molecular structure and corrosion inhibition mechanisms. Findings The results of the weight loss method show that when the dosage of DTEBTAC is 1%, the corrosion rate of N80 steel in hydrochloric acid solution at 90? is 3.3325 g m-2 h-1. Electrochemical and surface morphology analysis show that DTEBTAC can form a protective layer on the surface of N80 steel, and is a hybrid corrosion inhibitor that can inhibit the main anode. Quantum chemical parameter calculation shows that DTEBTAC has a better corrosion inhibition effect than DTP. The molecular dynamics simulation results show that DTEBTAC has stronger binding energy than DTP, and forms a network packing structure through hydrogen bonding, and the adsorption stability is enhanced. Originality/value A novel cationic mercaptopyrimidine derivative quaternium-ammonium salt corrosion inhibitor was designed and provided. Compared with the prior art, the preparation method of the synthesized mercaptopyrimidine derivative quaternary ammonium salt corrosion inhibitor is simple, and the presence of nitrogen-positive ions, sulfur atoms and nitrogen-rich atoms has an obvious corrosion inhibition effect, which can be used to inhibit metal corrosion during oil and gas field exploitation. It not only expands the application field of new materials but also provides a new idea for the research and development of new corrosion inhibitors.

Study of multi-elemental concentration and nano-micro structural morphology in medicinal plants by FE-SEM and EDX method.

Medicinal plants of the Moraceae family, such as Ficus racemosa linn, have been traditionally used in the North Karnataka region for treating various ailments. This study aims to analyze the elemental composition and nano-micro structural morphology of selected species of Moraceae family medicinal plants, focusing on their potential therapeutic applications. Samples were collected from the Dharwad and Gadag districts in North Karnataka. The surface morphology at nano and micro levels was examined using a field emission scanning electron microscope, while the elemental composition was analyzed through energy-dispersive X-ray spectroscopy. The study emphasizes the detailed examination of the specific weight percent of elemental concentration and the morphological features observed. The analysis revealed fine, irregularly shaped particles with an average diameter of 20 to 50 μm on the plant surface. Elemental composition analysis showed the presence of Mg, Al, Si, Cl, K, Ca, Mn, Fe, Cu, and Zn within WHO-recommended limits.

The tribological properties of PPS-PTFE/SiO2 coating deposited on the textured surfaces processed by ultrasonic rolling

In this paper, ultrasonic rolling textures were fabricated on 42CrMo steel substrates, and the polyphenylene sulfide-polytetrafluoroethylene/silicon dioxide (PPS-PTFE/SiO2) lubricating coatings were deposited on the textured surfaces to improve the tribological properties of the coating-substrate system. The influences of textures with different shapes (spiral, linear, wavy textures) and step distances (100, 150, 200, 250 μm) on the surface morphologies and strengthening effects of the substrates were investigated. The results showed the wavy texture with a step distance of 200 μm had the best strengthening effect, which increased the surface hardness and residual compressive stress by 126.1% and 5.1 times compared to the substrate, respectively. The influences of different textures on the friction and wear properties of lubricating coatings were studied by dry reciprocating friction testings. The results showed that the coating on the spiral textured surface with a step distance of 250 μm had the best tribological properties, and the average friction coefficient and wear rate were reduced by 45.5% and 49.5% compared to the coating on the substrate. The influence of ultrasonic rolling texture on the tribological properties of the lubricating coating was a combined result of the strengthening effect and texture structure. The strengthening effect provided a steady gain, while the texture structure provided either a gain or a deterioration.

Roughness affects the response of human fibroblasts and macrophages to sandblasted abutments

BackgroundA strong seal of soft-tissue around dental implants is essential to block pathogens from entering the peri-implant interface and prevent infections. Therefore, the integration of soft-tissue poses a challenge in implant-prosthetic procedures, prompting a focus on the interface between peri-implant soft-tissues and the transmucosal component. The aim of this study was to analyse the effects of sandblasted roughness levels on in vitro soft-tissue healing around dental implant abutments. In parallel, proteomic techniques were applied to study the interaction of these surfaces with human serum proteins to evaluate their potential to promote soft-tissue regeneration.ResultsGrade-5 machined titanium discs (MC) underwent sandblasting with alumina particles of two sizes (4 and 8 μm), resulting in two different surface types: MC04 and MC08. Surface morphology and roughness were characterised employing scanning electron microscopy and optical profilometry. Cell adhesion and collagen synthesis, as well as immune responses, were assessed using human gingival fibroblasts (hGF) and macrophages (THP-1), respectively. The profiles of protein adsorption to the surfaces were characterised using proteomics; samples were incubated with human serum, and the adsorbed proteins analysed employing nLC–MS/MS. hGFs exposed to MC04 showed decreased cell area compared to MC, while no differences were found for MC08. hGF collagen synthesis increased after 7 days for MC08. THP-1 macrophages cultured on MC04 and MC08 showed a reduced TNF-α and increased IL-4 secretion. Thus, the sandblasted topography led a reduction in the immune/inflammatory response. One hundred seventy-six distinct proteins adsorbed on the surfaces were identified. Differentially adsorbed proteins were associated with immune response, blood coagulation, angiogenesis, fibrinolysis and tissue regeneration.ConclusionsIncreased roughness through MC08 treatment resulted in increased collagen synthesis in hGF and resulted in a reduction in the surface immune response in human macrophages. These results correlate with the changes in protein adsorption on the surfaces observed through proteomics.

Tribological behaviors and wettability evolution of phenolic resin-impregnated graphite materials under water immersion condition

This study investigated the tribological behaviors of two phenolic resin-impregnated graphite samples and one non-impregnated sample under dry and water immersion using a reciprocating testing device. The frictional configuration involved a steel hemisphere sliding against the surface of the graphite samples. The influence of water immersion time before each formal test on friction coefficients was discussed. The wettability evolution during the test processes and the difference in porosity, which could significantly affect water infiltrating into the sample matrix and frictional interfaces, were associated with the variation in tribological behaviors. The worn surface morphology and element analysis results indicated that the shallow valleys and pores on the surface of graphite were gradually filled by wear debris from both the graphite samples and the harder counterpart. Based on these experimental results, a tribological mechanism of the phenolic resin-impregnated graphite materials under water immersion was developed.

Comparative study of sodium and potassium compounds as promoters for growth of monolayer MoS2 with high crystal quality on SiO2/Si substrate

Monolayer MoS2 is promising candidate for fabrication of optoelectronic devices due to its direct bandgap nature and high carrier mobility. Alkali metal compounds have been demonstrated to be helpful promoters for the growth of large single crystal monolayer MoS2 on SiO2/Si substrate. However, the catalytic mechanism of alkali metal compounds is still under debate. Herein, we compared the surface morphology, optical properties, and electrical properties of monolayer MoS2 flakes grown on SiO2/Si substrate assisted by promoters containing potassium or sodium cations and halogen (chlorine) or non-halogen (hydroxide) anions, i.e. NaCl, NaOH, KCl and KOH. Based on the analysis of existing growth mechanism, we proposed that the alkali metal cation, plays a dominant role in promoting the lateral growth of monolayer MoS2 and obtaining high crystal quality. Furthermore, potassium has a greater promoting effect than sodium. By optimizing growth conditions, monolayer triangular MoS2 flakes with large lateral size over 160 μm were grown assisted by KCl promoter. Raman and PL spectra verified excellent crystal quality of the flakes, with typical electron mobilities of 2.98 and 20 cm2 V−1 s−1 for the back-gated filed effect transistors fabricated on as-grown and fresh SiO2/Si substrates, respectively.

Effects of Hexagonal Boron Nitride and Mesoporous Silica Nanoparticles on the Morphology, Mechanical Properties and Antimicrobial Activity of Dental Composites

AbstractHexagonal boron nitride (HBN), an artificial material with unique properties, is used in many industries. This article focuses on the extent to which hexagonal boron nitride and silica nanoparticles (MSN) affect the physicochemical and mechanical properties and antimicrobial activity of prepared dental composites. In this study, HBN, and MSN were used as additives in dental composites. 5% and 10% by weight of HBN are added to the structure of the composite materials. FTIR analysis were performed to determine the components of the produced boron nitride powders, hexagonal boron nitride-containing composites, and filling material applications. The structural and microstructural properties of dental composites have been extensively characterized using X-ray diffractometry (XRD). Surface morphology and distributions of nano boron nitride were determined by scanning electron microscopy (SEM)-EDS. In addition, the solubility of dental composites in water and their stability in water and chemical solution (Fenton) were determined by three repetitive experiments. Finally, the antimicrobial activity of dental composites was detected by using Minimum Inhibitory Concentration (MIC) measurement, as well as Minimum Fungicidal Concentration (MFC) method against yeast strain Saccharomyces cerevisiae, and Minimum Bactericidal Concentration (MBC) method against bacteria strains, Staphylococcus aureus and Escherichia coli. Since the HMP series have better antimicrobial activity than the HP series, they are more suitable for preventing dental caries and for long-term use of dental composites. In addition, when HMP and HP series added to the composite are compared, HMP-containing dental composites have better physicochemical and mechanical properties and therefore have a high potential for commercialization.

Modulating vacancies of graphene supported FeNi2S4 electrocatalysts by radio-frequency plasma for overall water splitting

Electrolysis of water for producing hydrogen is an effective and sustainable technique to meet the continuously increasing energy demand. Nevertheless, its advancement is impeded by the inadequate catalytic efficacy for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Vacancy defect engineering is a rational approach to simultaneously enhance the catalytic performance for both the half-reactions. However, controlling the vacancy defects is quite challenging. Here, we have employed a radio-frequency Ar plasma-assisted treatment strategy to prepare highly efficient graphene-supported FeNi2S4 bifunctional catalysts with abundant vacancies. The plasma treatment induces the formation of vacancy structures in the catalyst, modifying the free energy of reaction intermediates, surface morphology, and electronic structure as well as reducing the reaction barriers, thereby enhancing the catalytic performance. The optimized graphene-supported FeNi2S4 catalyst possesses abundant sulfur vacancies, demonstrating excellent electrocatalytic performance. At 50 mA cm−2, the overpotentials for OER and HER are 240 and 256 mV, respectively, indicating exceptional stability. Overall, this work offers valuable insights into the development of cost-effective and high-performance electrocatalysts for water electrolysis.

Evaluation of Physical Properties in Carboxymethyl Chitosan Modified Glass Ionomer Cements and the Effect for Dentin Remineralization: SEM/EDX, Compressive Strength, and Ca/P Ratio.

The aim of this article was to evaluate the effects of modifying glass ionomer cement (GIC) with carboxymethyl chitosan (CMC) on surface morphology and remineralization outcomes by examining dentin morphology and calcium ion composition changes. Thirty holes in a cylindrical acrylic mold were filled with three groups of restorative materials: GIC, GIC modified with CMC (GIC-CMC) 5%, and GIC-CMC10%. The surface morphology of each group's materials was observed using scanning electron microscopy (SEM). The compressive strength measurement was performed using a universal testing machine. The dentin remineralization process was performed by applying GIC, GIC-CMC5%, and GIC-CMC10% materials for 14 days on demineralized dentin cavities treated with 17% ethylenediamine tetraacetic acid (EDTA) for 7 days. A morphological evaluation was conducted using SEM. The calcium ion composition and calcium-to-phosphorous (Ca/P) ratio were examined using an energy-dispersive X-ray (EDX). The Kruskal-Wallis and post-hoc Mann-Whitney U tests were performed to compare all four groups of calcium ions (p < 0.05). The modification of GIC with CMC affected the morphological changes in the materials in the form of reduced porosity and increased fractures. A significant difference was found in compressive strength between the GIC-CMC modification materials of GIC-CMC5% and GIC-CMC10% and the GIC control group. The dentin tubule morphology and surface changes were observed after applying GIC, GIC-CMC5%, and GIC-CMC10% materials for 14 days, as evaluated by SEM. The EDX examination showed an increase in calcium ion content and hydroxyapatite formation (Ca/P ratio) after applying the GIC-CMC10% material. The surface porosity of the GIC modification material with the addition of CMC tended to decrease. However, an increase in cracked surfaces that widened, along with the rise in CMC percentage, was found. This modification also reduced the compressive strength of the materials, with the lowest average yield at 10% CMC addition. Therefore, the modification of GIC with CMC affects changes in morphology, calcium ion composition, and Ca/P ratio in demineralized dentin.

Comparative study of the structural, magnetic and electrical properties of cuprous delafossites CuBO2(B = Zn, Mn and Er) prepared using the flash auto-combustion technique

Abstract The flash auto-combustion method was utilized to produce Cu-based delafossites of CuBO2 (B = Zn, Mn, and Er). X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS) were employed to verify the phase formation, surface morphology, and oxidation states of the synthesized delafossite samples. The crystallite sizes were determined to be 43, 16.76, and 21.66 nm for CuZnO2, CuMnO2, and CuErO2 nanoparticles (NPs), respectively. The magnetic characteristics of CuZnO2, CuMnO2, and CuErO2 samples were studied at room temperature, revealing their paramagnetic nature through the hysteresis effect. The Seebeck coefficient (S) for CuZnO2 was found to be positive, while it was negative for CuMnO2 and CuErO2. The thermoelectric power of CuZnO2 NPs was high, indicating their potential as materials for more efficient thermoelectric devices. Additionally, CuZnO2 exhibited an antimicrobial response against four-gram (+ve) bacteria, four-gram (-ve) bacteria, and the fungus Candida albicans (CA). The data obtained demonstrated that CuZnO2 NPs altered bacterial cell morphology, ultimately leading to bacterial cell death.&amp;#xD;

Epoxidized Soybean Oil Toughened Poly(lactic acid)/Lignin-g-Poly(lauryl methacrylate) Bio-Composite Films with Potential Food Packaging Application

The application of lignin as a filler for poly (lactic acid) (PLA) is limited by their poor interfacial adhesion. To address this challenge, lignin-graft-poly(lauryl methacrylate) (LG-g-PLMA) was first blended with poly (lactic acid), and then epoxidized soybean oil (ESO) was also added to prepare PLA/LG-g-PLMA/ESO composite, which was subsequently hot pressed to prepare the composite films. The effect of ESO as a plasticizer on the thermal, mechanical, and rheological properties, as well as the fracture surface morphology of the PLA/LG-g-PLMA composite films, were investigated. It was found that the compatibility and toughness of the composites were improved by the addition of ESO. The elongation at break of the composites with an ESO content of 5 phr was increased from 5.6% to 104.6%, and the tensile toughness was increased from 4.1 MJ/m3 to 44.7 MJ/m3, as compared with the PLA/LG-g-PLMA composite without ESO addition. The toughening effect of ESO on composites is generally attributed to the plasticization effect of ESO, and the interaction between the epoxy groups of ESO and the terminal carboxyl groups of PLA. Furthermore, PLA/LG-g-PLMA/ESO composite films exhibited excellent UV barrier properties and an overall migration value below the permitted limit (10 mg/dm2), indicating that the thus-prepared biocomposite films might potentially be applied to environmentally friendly food packaging.

A review on the current status of dye‐sensitized solar cells: Toward sustainable energy

AbstractDye‐sensitized solar cells (DSSCs) are among the most attractive third‐generation photovoltaic technologies due to their low toxicity, versatility, roll‐to‐roll compatibility, ultralightness, and attractive power conversion efficiencies (PCEs). However, their transition from the laboratory scale to the industrial scale has been slow due to their inability to compete with silicon‐based cells in terms of efficiencies and stabilities. Research activities on DSSCs have been ongoing for several decades to improve the efficiency and cost‐effectiveness of photovoltaics but these attempts are still inadequate. Their chemical and physical properties must be refined to increase efficiency and commercialization. This review provides a concise overview of the recent advances taking place in the DSSCs research field, including molecular engineering technologies, the quest for superior carrier transport materials (CTMs), efficient sensitizers, and better electrodes. Also, this review compiles knowledge of the historical development of DSSCs, the current advancements such as control of surface morphologies, doping strategies, modeling and simulation, characterization, and recent cutting‐edge research happenings in photovoltaic research. Finally, nanostructured materials that have been used as photoelectrodes and the practical applications of DSSCs in internet of things (IoT) and portable electronics are examined to identify challenges and future advancements. The main aim of this work is to be a pathfinder for scientific researchers in this field exploring various energy harvesting materials and optimization strategies of different components of DSSCs.

Electric and dielectric responses of Au/n-Si structure by Mn doped PVC interfacial layers

This paper has investigated and compared the impact of polyvinyl chloride (PVC) without/with manganese (Mn) metallic nanoparticles interfacial layer on the electric and impedance characteristics of Schottky diode (SD) with a structure of Au/n-Si (MS). The structures of these two metal-polymer-semiconductor (MPS) SDs are Au/PVC/n-Si and Au/PVC:Mn/n-Si. A detailed description of the SDs manufacturing process is given. The x-ray diffraction (XRD) analysis, Scanning Electron Microscope (FE-SEM) images, and Electron Dispersive x-ray (EDX) spectroscopy are three methods that have been utilized to examine mean size of crystallite, morphology of surface, purity specification. The fundamental electronic variables of these devices are ascertained and contrasted with one another using the I-V characteristic measurement at ±6 V. Ohm’s law, Thermionic Emission (TE) theory, modified Norde, and Cheung functions are used to calculate the SDs’ leakage current (I0), ideality coefficient (n), potential barrier height (BH), shunt (Rsh), and series (Rs) resistances. Investigations are conducted on the energy dependence of surface states density (Nss) and the current conduction mechanisms (CCMs) for both reverse and forward biases. These interfacial layers are known to decrease the n, Rs, and Nss. The PVC polymer interlayer leads to improve the efficiency of the MS-type SD, but it does not when doped by Mn nanoparticles. Additionally, by measuring impedance at a bias of 1.5 V and 100 Hz-1 MHz frequency range, the frequency dependence of dielectric properties of the prepared SDs is studied. The dielectric permittivity, dielectric loss tangent, electronic modulus, and ac electronic conductivity of these SDs are all studied.

The time evolution of electrical and thermodynamic characteristics of surface dielectric barrier discharge caused by dielectric degradation

Abstract The degradation of the dielectric layer is a common issue in dielectric barrier discharge (DBD). The performance of DBD devices may suffer from instability due to potential corrosion of the dielectric layer caused by discharge, which could even result in structural failure. To gain a comprehensive understanding of the degradation of DBD devices during discharge, the evolution of the performance of DBD devices with various dielectric materials over time is studied. Periodic patterns are found to form on the dielectric surface along the edge of the high-voltage electrode. The electrical data, emission spectra, and surface morphologies of DBD devices with three different dielectric materials, namely ceramics, glass, and PCB, are obtained during an eight-hour discharge. The electrical and thermodynamic characteristics of DBD devices with the three dielectric materials are found to initially decrease by about 20~40%. Subsequently, they remain stable in devices with ceramics and PCB dielectric layers but increase in devices with glass dielectric layers until the end. Surface morphologies reveal that periodic patterns consisting of metal accumulations, etching pits, and metal depositions form on the surfaces of ceramics, glass, and PCBs, respectively. Some organic compounds vaporize from the surface of PCBs. The deposition, etching, and vaporization could be reasons for changes in the electrical and thermodynamic characteristics. It shows that degradation occurs not only in organic dielectrics like polymers but also in inorganic dielectrics such as ceramics and glass. To enhance stability and prevent potential failures and overestimations, electrical and optical measurements could be utilized as diagnostic methods in applications involving DBD devices.&amp;#xD;&amp;#xD;

Ultrasonic assisted green synthesis of CuO nanoparticles: a real catalytic and antimicrobial agent

ABSTRACT This study reported facile biosynthesis of CuO nanoparticles employing leaf extract of Prosopis glandulosa as a stabilising agent by modest ultrasonic assisted technique. The synthesised nanoparticles were characterised via greatly refined systems comprising UV-visible, FTIR, XRD, SEM EDX, Zeta sizer, and Zeta potential. These facilities triggered the study of optical, functionality, crystallinity, surface morphology, elemental composition, and surface potential of the synthesised nanoparticles. The SEM and FT-IR analysis confirmed the semi-spherical shapes and functionalities of the synthesised NPs respectively. The zeta size and zeta potential of CuO NPs were established to be 65 nm and −1.42 mV respectively. The resultant NPs were applied as an efficient antimicrobial and catalytic candidate for the successful degradation of Eriochrome Black T (EBT) dye. Various factors were optimised such as dose, time, and NaBH4 concentration to achieve maximum catalytic efficiency of CuO nanoparticles. The NPs show excellent catalytic performance of about 92% degradation of EBT within 30 minutes. The antimicrobial performance was also tested by varying the concentration of NPs (250, 500, 1000, and 2000 g/mL via disc diffusion protocol. The results show that CuO NPs have excellent antibacterial activity alongside E. coli at MIC values of 250 g/mL as equated to S. areas and Aspergillus niger.

3D Nickel–Manganese bimetallic electrocatalysts for an enhanced hydrogen evolution reaction performance in simulated seawater/alkaline natural seawater

In this paper, we report an inexpensive one-step synthesis of self-supported 3D nickel-manganese (NiMn) bimetallic coatings and their application for the hydrogen evolution reaction in simulated seawater (1 M KOH + 0.5 M NaCl) and alkaline natural seawater (1 M KOH + natural seawater). These binary coatings were electrodeposited on a titanium substrate using a facile electrochemical deposition method by a dynamic hydrogen bubble template technique. The as-deposited NiMn coatings with variable Mn amounts produce typical globular and unique porous architecture with abundant pores of different sizes. The activity of these fabricated catalysts towards the hydrogen evolution reaction was investigated by linear sweep voltammetry towards simulated seawater and alkaline natural seawater at different temperatures. The surface morphology and composition of the catalysts were also characterized by scanning electron microscopy and inductively coupled plasma optical emission spectroscopy. The as-prepared NiMn/Ti electrocatalyst, which was electrodeposited using a chemical bath containing Ni2+ and Mn2+ ions with a molar ratio of Ni2+:Mn2+ = 1:5, exhibits excellent hydrogen evolution activity in simulated seawater with an ultra-low overpotential of 64.2 mV to reach a current density of 10 mA cm−2. It is noteworthy that this NiMn/Ti electrocatalyst also achieves a current density of 10 mA cm−2 in alkaline natural seawater with a comparably low overpotential of 79.3 mV. The current densities increase by ca. 1.75–2.35 times with an increase in temperature from 25 °C to 75 °C for hydrogen evolution in both electrolytes. This bimetallic catalyst has shown excellent long-term stability at a constant potential of −0.23 V (vs. RHE) and a constant current density of 10 mA cm−2 for 10 h, which ensures higher durability and robustness for practical application of seawater splitting technology.

Forecasting chaotic behavior of the drill bit in real-time using a DNN model integrated with rock surface morphology

The multiple regenerative effects during the drilling process cause the drilling system to exhibit complex motions, even leading to chaotic behavior. Additionally, due to the inability to obtain real-time rock parameters, traditional drilling dynamics models and time-series forecasting models cannot accurately forecast the real-time operational status of the drilling system. In this paper, a deep neural network (DNN) model integrated with rock surface morphology model is proposed to forecast the real-time operational status of the drill bit. This new model can permanently record the changes in rock surface morphology and multiple regenerative effects during the drilling process, enhancing the perception of rock parameters and improving the forecasting accuracy of the drill bit’s operational status. Experimental results show that the new model forecasts the drill bit’s operational status with higher accuracy compared to other typical time-series forecasting models without integrating surface morphology model. Furthermore, this new model demonstrates superior convergence speed, stability, and generalization ability compared to other models. In addition, the influence of hyperparameters on the forecast accuracy of the new model has also been studied. These results play an important role in forecasting and preventing adverse vibrations such as stick slip, impact, reversal, and rebound of the drill bit.