Variations In Surface Morphology Research Articles

Peroxymonosulfate activation with Co3O4 by microstructure engineering for efficient degradation of tetracycline: Efficiency, mechanism and stability

In recent years, advanced oxidation technologies employ peroxynitrite activation have exhibited exceptional effectiveness in eliminating various emerging contaminants. In this study, different calcination temperatures were used to derive Co3O4 nanospheres with varying surface morphologies. This method effectively addresses the issue of high cost associated with high-performance catalyst synthesis or poor catalytic performance of low-cost catalysts. The active species like O2•−, •OH, SO4•−, 1O2 played significant role in TC degradation and 1O2 was the dominant reactive oxygen species (ROS). The study also proposed possible degradation pathways based on the 15 intermediates identified through HPLC-MS. Furthermore, the developmental toxicity of the identified intermediates was evaluated using a quantitative conformational relationship prediction method. This paper delves into the reaction mechanism of Co3O4 nanospheres in the activation of PMS and examines the impact of surface morphology on their catalytic performance, providing a new approach to developing a persulfate catalyst that is cost-effective and has high catalytic performance, with a simple synthesis step.

Influence of zirconium and copper sub-layer in cell integrations on femtosecond laser-processed Ti thin films

The creation of novel biocompatible Ti-based thin films with a Zr or Cu sub-layer modified by ultrafast laser processing is studied. To prepare bioactive surfaces, ultrafast laser processing is focused on the formation of laser-induced periodic surface structures (LIPSS) with the production of oxide phases at the surfaces. Two differently designed multilayer thin films Ti/Cu/Ti and Ti/Zr/Ti were deposited on the silicon using the ion sputtering method. The Ti thin film contains Cu or Zr sub-layer (thickness of 10 nm) at the 10 nm below the surface. The composition and surface morphology variations for these systems, deposited and laser-processed under the same experimental conditions, were caused only by different thermo-physical properties of the sub-layer (Cu or Zr). The surface morphology in the form of LIPSS, led to improved cell adhesion and stable cells/thin films interface compared to as-deposited samples. Field-emission scanning electron microscopy and MTT analysis revealed that laser processing of both systems increased cell adhesion, proliferation, and metabolical activity of L929 mouse fibroblast cells compared to non-modified flat surfaces. Overall, the biocompatibility of Zr-containing thin films is better than Ti/Cu/Ti system. Further, laser processing and formation of LIPSS makes Ti/Zr/Ti thin films excellent candidate for biomedical .

Experimental study on erosion mechanism and pore structure evolution of bituminous and anthracite coal under matrix acidification and its significance to coalbed methane recovery

Acid fracturing is a potential method to resolve the mineralization restriction around wellbore and enhance the permeability in coalbed methane extraction. The previous study mainly focused on exploring the effect on permeability enhancement for oil reservoir. However, the performance of acid fracturing fluid in coal reservoir is still unclear. In this paper, the surface morphology and internal pore structure of coal were characterized by erosion rate test, scanning electron microscope-energy dispersive spectrum (SEM-EDS) and low-temperature nitrogen adsorption test (LT-N2GA), and the relationship between erosion rate and pore structure index of bituminous and anthracite coal under matrix acidification was obtained. The results show that the bituminous coal presented higher acid sensitivity than anthracite from no matter aspects of erosion rate, surface morphology and internal pore structure variation. The increment of erosion rate and pore structure index is increase with the coal ranks under matrix acidification, which can provide reference for the selection of acid pad fluids for acid fracturing in different coal seams.

Superhydrophobic Purple Orchid Leaves: Variation in Surface Morphology During the Vegetation Stages Leading to Diversity in Wettability

Superhydrophobic Purple Orchid Leaves: Variation in Surface Morphology During the Vegetation Stages Leading to Diversity in Wettability

Insights into the mechanism of plastics’ fragmentation under abrasive mechanical forces: An implication for agricultural soil health

AbstractThe application of agricultural plastic products such as mulch, greenhouse covers, and silage films is increasing due to their economic benefits in providing an early and better‐quality harvest. However, mechanical abrasion of these plastic materials by soil particles could result in generation of microplastic (MP) pollutants that could harm soil organisms and impact food safety. This study aims to better understand the physicochemical mechanisms resulting in the fragmentation of low‐density polyethylene (LDPE). Herein, we used pellets and films to study the impacts of abrasive wear forces on their surface morphology variations and fragmentation behavior. An innovative laboratory approach was developed to abrade the plastic surface under controlled normal loadings and abrasion durations. The investigation of the plastics’ surface morphology variations due to the abrasion process revealed microcutting as the dominant process at low normal force (4 N). However, a combination of microploughing and microcutting occurred for new LDPE films by increasing the normal force to 8 N. Despite the significant surface morphology variations of the new LDPE film due to the abrasion process; the water contact angle did not alter. Furthermore, the fragmentation behavior of photodegraded LDPE pellets and films was compared to the new plastics. The extent of MPs (3 µm < dp < 162 µm) generation due to fragmentation was studied using fluorescence microscopy imaging. The localized stress and strains at the contact sites of plastic and sand particles resulted in abrasion of the plastic surface. According to the results, the normal loadings and duration of abrasion played a significant role in the degree of fragmentation of plastics. Increasing the normal loading applied during the abrasion process from 2 to 8 N linearly increased the number of generated plastic fragments by more than five times for pellets and more than three times for film. Photodegradation significantly enhanced the extent of MPs fragmentation. Moreover, the limitations of this study and the implications for agricultural soil health were discussed.

Cytotoxicity of Metal Ions Released from NiTi and Stainless Steel Orthodontic Appliances, Part 1: Surface Morphology and Ion Release Variations.

Despite numerous studies on ion release from orthodontic appliances, no clear conclusions can be drawn due to complex interrelations of multiple factors. Therefore, as the first part of a comprehensive investigation of cytotoxicity of eluted ions, the objective of this study was to analyze four parts of a fixed orthodontic appliance. Specifically, NiTi archwires and stainless steel (SS) brackets, bands, and ligatures were immersed in artificial saliva and studied for morphological and chemical changes after 3-, 7-, and 14-day immersion, using the SEM/EDX technique. Ion release profiles were analyzed for all eluted ions using inductively coupled plasma mass spectrometry (ICP-MS). The results demonstrated dissimilar surface morphologies among parts of the fixed appliance, due to variations in manufacturing processes. The onset of pitting corrosion was observed for the SS brackets and bands in the as-received state. Protective oxide layers were not observed on any of the parts, but adherent layers developed on SS brackets and ligatures during immersion. Salt precipitation, mainly KCl, was also observed. ICP-MS proved to be more sensitive than SEM/EDX and exhibited results undetected by SEM/EDX. Ion release was an order-of-magnitude higher for SS bands compared to other parts, which was attributed to manufacturing procedure (welding). Ion release did not correlate with surface roughness.

A synthesis of double modified: Irradiated and oxidized corn starch and its microstructural and physicochemical properties

A low cost, environmentally friendly route to synthesize highly transparent, low-viscosity starch solution is in demand. In this work, pure corn starch was chosen and irradiated by an electron beam (EB) in air with dose up to 60 kGy, then, oxidized by Dess-Martin periodinane (DMP). Then, variations in chemical structure, surface morphology, thermal-stability, transparency, viscosity and gelatinization process were explored. Main results reveal that both irradiation and DMP treatment introduced molecular chain scission and hydrophilic structure generation, destroyed surface morphology, increased thermal-stability, transparency and viscosity-stability but decreased coagulation, viscosity and gelatinization temperature. Irradiation seems being more efficient than DMP treatment on starch modification and a dose of 4–10 kGy irradiation can be effective. DMP treatment can modify starch while the efficiency is dose-dependent. At low dose such as 4–10 kGy it is visible while at higher dose it is moderate. Generally, via a combined low dose such as 4–10 kGy irradiation and a middle level DMP treatment highly transparent, low-viscosity, viscosity-stable starch solution can be formed, possibly having a potential use in the food or textile industry.

In Situ Formation of Conductive Epidermal Electrodes Using a Fully Integrated Flexible System and Injectable Photocurable Ink.

In situ fabrication of wearable devices through coating approaches is a promising solution for the fast deployment of wearable devices and more adaptable devices for different sensing demands. However, heat, solvent, and mechanical sensitivity of biological tissues, along with personal compliance, pose strict requirements for coating materials and methods. To address this, a biocompatible and biodegradable light-curable conductive ink and an all-in-one flexible system that conducts in situ injection and photonic curing of the ink as well as monitoring of biophysiological information have been developed. The ink can be solidified through spontaneous phase changes and photonic cured to achieve a high mechanical strength of 7.48 MPa and an excellent electrical conductivity of 3.57 × 105 S/m. The flexible system contains elastic injection chambers embedded with specially designed optical waveguides to uniformly dissipate visible LED light throughout the chambers and rapidly cure the ink in 5 min. The resulting conductive electrodes offer intimate skin contact even with the existence of hair and work stably even under an acceleration of 8 g, leading to a robust wearable system capable of working under intense motion, heavy sweating, and varied surface morphology. Similar concepts may lead to various rapidly deployable wearable systems that offer excellent adaptability to different monitoring demands for the health tracking of large populations.

Study on force-thermal characteristics and cutting performance of titanium alloy milled by ultrasonic vibration and minimum quantity lubrication

Ti-6Al-4V alloys are widely utilized in aerospace field because of its excellent physical and mechanical performance. Nevertheless, titanium alloy has high strength and low thermal conductivity, which leads to poor processability. Therefore, in the titanium alloys cutting processing, decreasing cutting force and cutting temperature are reliable ways to improve its cutting machinability. The high-frequency intermittent cutting effect of ultrasonic vibration be beneficial to reduce the milling force, and the minimum quantity lubrication (MQL) technology can efficiently improve the friction environment and decrease the cutting temperature. Combined with the technological superiority of ultrasonic vibration assisted machining (UVAM) and MQL, this paper proposes to use UVAM&MQL technology for titanium alloy milling. Firstly, theoretical analysis shows that the separation property of UVAM can enhance the cooling/lubrication of MQL, and the coupling action of UVAM and MQL can improve the force and temperature generated in the cutting process. Then, the variation of surface roughness, surface morphology and chip morphology under this force-thermal coupling is discussed through milling experiments, and compared with conventional milling (CM) and UVAM. From the results, we make out that compared with CM, both UVAM and UVAM&MQL can reduce the cutting force. When the cutting speed is high, UVAM can't reduce the cutting temperature, while UVAM&MQL produces a smaller cutting temperature under all parameters. When the UVAM&MQL method is adopted for processing, the surface is smoother, and the surface forms a clear and uniform vibration texture. Compared with CM and UVAM, the surface roughness of UVAM&MQL is decreased by about 27–51 % and 5–44 %, respectively. In addition, UVAM&MQL method is beneficial to promote the transformation of serrated chip to non-serrated chip.

Black carbon derived from pyrolysis of maize straw and polystyrene microplastics affects soil biodiversity

Understanding the environmental correlation of microbial community under external stimulation is significant for ecological restoration. However, few studies focused on the response of soil biodiversity induced by black carbon (BC) derived from pyrolysis of straw and microplastics (MPs) due to their widespread existence in natural environment. In this study, polystyrene MPs (PS) and maize straw with different mass ratios were used as raw materials to prepare BC by pyrolysis. The surface morphology, chemical composition and sequential variations of different functional groups of BC were systematically analyzed. The leachate from BC was identified by three-dimensional excitation emission matrice (3D-EEM). The corresponding results showed that yield, value of O/C and N element content of BC decreased with more PS. The changed C content and oxygen-containing functional groups occurred. The order of functional groups of BC formed by co-pyrolysis was: C=C > C-O > C-H > Si-O-Si. The main component of leaching from BC was humic-like and fulvic-like acid. Simultaneously, the input of exogenous BC into soil affected abundance, composition and metabolic pathways of microorganisms. The study helps to understand environmental implication of BC which was pyrolyzed from maize straw and MPs, providing an idea for improving biogeochemical cycle process in soil.

Production of exopolysaccharides from Bacillus licheniformis, a thermophilic bacteria from hot spring of Jharkhand

Thermophiles are the microorganisms which thrive under extreme conditions such as high temperature, making them significant for scientific interest. This study provides information based on isolation of thermophilic strain from Surajkund and Ramkund, hot spring of Jharkhand at 50, 60 and 70 °C. Two of the best isolates were used for the extraction of exopolysaccharides. Additionally, the lyophilized product obtained was further analyzed for protein and total sugar estimation. The FTIR analysis revealed the presence of different functional groups such as hydroxyl, C–H stretching, vibration of aliphatic CH2 and glycosidic linkage, thus proving the product obtained from bacteria was an exopolysaccharides The FESEM analysis of exopolysaccharides show varying surface morphology that is from porous to globular structure. Based on 16S rRNA sequences, the isolates from Surajkund (ON795919) and Ramkund (ON795916) were different strains of Bacillus licheniformis. This is the first report on exopolysaccharide secreting thermophilic strain from these hot springs.

Surfactant Assisted Synthesis of BiVO4 by Low Temperature Solvothermal Method: Effect of Calcination for Photocatalytic Activity

A visible light active semiconductor photocatalyst, BiVO4 was synthesized through low temperature solvothermal method in hot air oven followed by calcination. To enhance the degradation rate surfactants were employed, which shows the better degradation for calcinated hexamine added BiVO4, i.e. 74% of methylene blue was degraded in 180 min in visible light irradiation. The result is correlated with lower band gap energy value, i.e. 2.07 eV and lower photoluminescence emission spectra intensity. It was observed the variation in surface morphology of the prepared samples. The specific surface area of calcinated hexamine added BiVO4 was analyzed by BET analysis. All the prepared samples showed higher absorption in UV-visible region. The FTIR confirmed the presence of hexamine in the calcinated hexamine sample.

The Impact of Zn doping on structural and optical behavior of SrO2 NPs and Anti-Microbial activities for Zn@SrO2 NPs

In the proposed study, pure SrO2 and Zn@SrO2 were synthesized using a simple, effective, and economical sol–gel assisted hydrothermal technique (NPs). The structural, optical morphological, and biological activities of the prepared nanoparticles at various concentrations, such as 0, 10, and 20 wt%, were studied utilizing a variety of techniques. For pure SrO2 and Zn@SrO2 nanoparticles, the XRD showed tetragonal and hexagonal structures, respectively. When compared to Zn@SrO2 Nano particles, the pure SrO2 surface morphology variations, as seen by scanning electron microscopy (SEM). The examination of elemental compositions has determined that Sr, Zn, and O are present. Band gap (Eg) diminished from 5.92 to 5.65 eV with a rise in doping concentration, according to optical characterization of the sample, which was measured by UV–visible spectra. Diverse functional groups, including CO, OH, and CC, were validated using Fourier-transform infrared spectroscopy (FTIR). Gram-positive and gram-negative microorganisms were used in antibacterial investigations. The outcome showed that Zn@SrO2 particles had increased the antibacterial action against a bunch of microscopic organisms, and its presentation was enhanced with the gradual addition of Zn particle focus within SrO2 NPs.

Oxidation resistances of polyamide nanofiltration membranes to hydroxyl and sulfate radicals

The oxidation compatibility with polyamide membranes is an important feature of nanofiltration (NF) technology in practical water treatment processes. In this study, we systematically investigated the oxidation resistance of fully aromatic (NF90) and semi-aromatic (NF270) polyamide NF membranes to reactive oxidative species including SO4•- and HO• in terms of membrane surface properties and filtration performance. SO4•− and HO• exhibit different oxidative behaviors in NF membranes with different polyamide structures. The HO•-dominated oxidation significantly damaged the membrane integrity of NF90 and NF270, with notably varied surface morphology, hydrophilicity, and charge. Further analysis of the chemical property on membrane surfaces revealed that the SO4•−-dominated oxidation was more reactive to the N moieties (N–H or N–C) of the NF90 membrane, whereas HO• unselectively reacted with polyamides. The radicals also impact the permselectivity (water permeability and salt rejection) of the NF90 and NF270 membranes in different ways. The NF90 membrane after SO4•−-exposure exhibited higher water permeability and slightly decreased salt rejection, whereas the permselectivity of the NF270 membrane was more significantly affected by HO•-exposure. To further reveal the underlying oxidation mechanisms, polyamide monomers were selected to react with the peroxodisulfate solutions. The results demonstrated that a fully aromatic polyamide membrane was more resistant to oxidative radicals than a semi-aromatic polyamide membrane. This study will facilitate the development of novel antioxidant membranes and provide information for selecting appropriate membrane materials in specific water treatment processes.

Supercapacitive amino-functionalized cobalt and copper metal-organic frameworks with varying surface morphologies for energy storage

• Two MOFs with Cobalt and Copper metal centres were analysed for SC application. • Co-BDC-NH 2 display superior capacitive behaviour than Cu-BDC-NH 2 . • Co-BDC-NH 2 electrode has specific capacitance of 291 F g −1 at current density of 1 A g −1 . • Co-BDC-NH 2 preserved 86 % of its initial capacity after 1000 cycles. • Nitrogen containing Co-BDC-NH 2 electrode proved to be a promising contender for SCs. In this study, two amino functionalized metal-organic frameworks, Co-BDC-NH 2 and Cu-BDC-NH 2 , using Cobalt and Copper as a metal sources were synthesized, extensively characterised, and employed as an electrode material in supercapacitors (SCs). Their synthesis provides an affordable and cost-effective technique in the energy sector because these MOFs are created from an inexpensive and easily accessible metal salts and ligands. FTIR, Raman, PXRD, TGA, FESEM, TEM and XPS analysis confirm the formation of Co-BDC-NH 2 and Cu-BDC-NH 2 . Co-BDC-NH 2 as an electrode material shows great cycling stability, high specific capacitance (291 F g −1 at 1 A g −1 ), high energy and power density as compared to Cu-BDC-NH 2 . The Co-BDC-NH 2 //3MKOH//Co-BDC-NH 2 symmetric supercapacitor has an energy density of 1.67 W h kg −1 with a power density of 299.7 W kg −1 at 1 A g −1 current density whereas the Co-BDC-NH 2 //3MKOH//AC asymmetric supercapacitor delivered a maximum energy density of 17.6 Wh kg −1 at a power density of 746 W kg −1 within the voltage range of 0 to 1.5 V, which are higher than those of PCN//AC BSH devices (16.0 Wh kg −1 at 749 W kg −1 ). Furthermore, there was a consistent cycling performance of ∼ 86 % capacitance following 1000 cycles for symmetric supercapacitor. These findings indicate that Co-BDC-NH 2 with rich nitrogen content forms a promising basis for improving high-performance electrochemical energy storage systems, and that such materials are extremely attractive for future energy advancement.

Heavily boron-doped diamond grown on scalable heteroepitaxial quasi-substrates: A promising single crystal material for electrochemical sensing applications

In this work, three distinct heteroepitaxial single-crystal boron-doped diamond (SC-BDD) electrodes were fabricated and subjected to detailed surface analysis and electrochemical characterization. Specifically, the heteroepitaxy approach allowed to synthesize large-area (1 cm2) and heavily-doped (100)-oriented SC-BDD electrodes. Their single-crystal nature and crystal orientation were confirmed by X-ray diffraction, while scanning electron and atomic force microscopies revealed marked variations in surface morphology resulting from their growth on respective on-axis and off-axis substrates. Further, absence of sp2 impurities along with heavy boron doping (>1021 cm−3) was demonstrated by Raman spectroscopy and Mott-Schottky analysis, respectively. Cyclic voltammetry (CV) in a 0.1 M KNO3 solution revealed wide potential windows (∼3.3 V) and low double-layer capacitance (<4 μF cm−2) of the SC-BDD electrodes. Their highly conductive, ‘metal-like’ nature was confirmed by CV with [Ru(NH3)6]3+/2+ probe manifesting near-reversible redox response with ΔEp approaching 0.059 V. The same probe was used to record scanning electrochemical micrographs, which clearly demonstrated homogeneously distributed electrochemical activity of the heteroepitaxial SC-BDD electrodes. Minor differences in their electrochemical performance, presumably resulting from the somewhat different morphological features, were only unveiled during CV with surface sensitive compounds [Fe(CN)6]3−/4− and dopamine. The latter was also used to show the possibility of applying herein developed heteroepitaxial SC-BDD electrodes for electrochemical sensing, whereas experiments with anthraquinone-2,6-disulfonate revealed their enhanced resistance to fouling. All in all, heteroepitaxial SC-BDD represents a highly attractive electrode material which can, owing to the fabrication strategy, easily overcome size limitation, currently preventing broader use of single crystal diamond electrodes in electrochemical applications.

Wettability Variation of Different Nickel Surface Morphologies Prepared by Electrodeposition and UV Illumination

Wettability Variation of Different Nickel Surface Morphologies Prepared by Electrodeposition and UV Illumination

Plant Carbon Sources for Denitrification Enhancement and Its Mechanism in Constructed Wetlands: A Review

Nitrogen pollution in water bodies is a serious environmental problem worldwide. Plant carbonsource (PCS) enhanced denitrification in constructed wetlands (CWs) for wastewater with low chemical oxygen demand to total nitrogen (COD/N) has been one of the most exciting research topics. This paper summarized the related studies with VOSviewer software and found that the major interests were denitrification performance and mechanism in CWs. This article mainly focused on the PCSs’ characteristics, denitrification rate, the influences of key environmental and operational parameters, surface morphology variation, microbial community structure, and denitrification genes. Engineering prospects and existing problems were also introduced. PCSs’ degradation consumes DO and creates favorable conditions for denitrification. The COD/N of wastewater should be maintained at 4–5 by adding PCSs, thus improving denitrification performance and reducing nitrous oxide emission. Aerobic degradation, anaerobic fermentation, dissimilatory nitrate reduction to ammonium, and sulfate reduction processes may consume the carbon released by PCSs depending on the influent quality and environmental conditions. More attention should be paid to the reduction of greenhouse gases and emerging pollutants in CWs with PCSs.

Effect of loading current on the arc erosion behavior of in-situ composite fiber-reinforced Ag–Cu–Ni–Ce alloy

To reveal the arc erosion behavior of in-situ composite fiber-reinforced electrical contact materials, arc erosion tests of an Ag–Cu–Ni–Ce alloy with the voltage of 24 V DC and a current ranging from 10 to 20 A were performed and the surface morphology, elemental distribution, and mass variations caused by arc erosion were investigated. The results found that, with the increase of load current, the arc erosion ratio and mass loss of contacts gradually increase. With a load current of 10 A, the contact resistance was lower, approximately one mΩ. The direction of material transfer was from the anode to the cathode, and the erosion mechanism was dominated by splashing and evaporation of the anode metal by short arc action. When the load current increased to 12 A, the contact resistance reached the maximum value of 5 mΩ. Then, it gradually decreased with increasing load current. The direction of material transfer was from the cathode to the anode, and the mechanism of erosion was mainly the bombardment of the cathode by gaseous positive ions by the long arc. At the same time, the results of the comparative analysis demonstrate that the in-situ composite fiber-reinforced Ag–Cu–Ni–Ce alloy has excellent arc erosion resistance.

Study on the working performance of CrAlCN coated and uncoated carbide twist drill

A drilling test was carried out for a 6 mm diameter carbide twist drill with CrAlCN coating and an uncoated carbide twist drill to grasp the effect of CrAlCN coating on the tool performance. Drilling and machining tests on ASTM1045 steel workpieces using CrAlCN coated and uncoated tools. Observe the pattern of variation of surface morphology and roughness of holes with the number of drilled holes using SEM and optical microscope. The effect of CrAlCN coating on carbide twist drill on drilling quality was analyzed by comparing the wear, surface roughness and chip shape of twist drill at different periods and parameters of drilling. The study concluded that using CrAlCN coated tools improved the wear resistance of the drill and significantly reduced BUE. Compared to the uncoated bit, the diameter of the drill decreased to 5.91 mm for the coated tool and 5.79 mm for the uncoated tool after 80 holes. The roughness of the coated bit was 3.324 µm at a feed rate of 0.12 mm/r and several holes of 40, which was significantly lower than that of the uncoated bit. Chip analysis showed that the coated tool maintained well-broken and tightly spiraled chips. In contrast, the uncoated tool produces tightly spiraled chips and short ribbon chips at a feed rate of 0.18 mm/rev, and the edges of the chips can appear significantly serrated. The research results improve the understanding of the drilling wear mechanism, provide new technical means to improve the analysis of working tool performance and provide a reference basis for the design of new coating tools.