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This study presents the design and simulation of an RF MEMS variable capacitor with a high tuning ratio and high linearity factor of capacitance–voltage response. An electrostatic torsion actuator with planar and non-planar structures is presented to obtain the high tuning ratio by avoiding the occurrence of pull-in point. In the proposed design, the capacitor plate is connected to the electrostatic actuators by using the s-shaped beam. The proposed design shows a 138% tuning ratio with the planar structure of the actuator and 167% tuning ratio by implementing the non-planar structure. A linearity factor of 99% is attained by adjusting the rates at which the capacitor plate rises as the actuation voltage increases and the rate at which the capacitance decreases as the plate rises. Parametric optimization of the design is performed by utilizing the finite element method (FEM) analysis and high-frequency structural simulator (HFSS) analysis to obtain an optimized high-tuning ratio RF MEMS varactor at low actuation voltage. S-parameters of the design are presented on HFSS, with a 50 ohm coplanar waveguide (CPW) serving as the transmission line. The proposed RF MEMS varactor can be utilized in tunable RF devices. [ABSTRACT FROM AUTHOR]

The manufacturing and characterization of nanographite films on substrates form the foundation for advances in materials science. Conductive graphite films are challenging products, as isolating graphite oxide is often necessary. In this study, nanographite suspensions containing non-oxidized graphite flakes were used to fabricate novel thin and ultrathin films via blade coating on industry-standard substrates. Films as thin as 346 nm were successfully fabricated. Moreover, it was possible to induce the orientation of the graphite nanoflakes via blade coating. This orientation led to electrical anisotropy; thus, the electrical behavior of the films in each orthogonal direction differed. After adjusting the coating parameters and the concentration of the nanographite flakes, the electrical conductivity ranged from 0.04 S/cm to 0.33 S/cm. In addition, with such adjustments, the transparency of the films in the visible range varied from 20% to 75%. By establishing a methodology for the tuning of both electrical and optical properties via adjustments in the nanographite suspension and coating parameters, we can fabricate resistant, conductive, and transparent films satisfying certain requirements. The results presented here can be extrapolated to enhance applications, especially for photonics and solar cells, in fields that require electrical conductive materials with high levels of transparency. [ABSTRACT FROM AUTHOR]

This study investigates the influence of microstructure patterns on the hydrophobic properties of surfaces of 3D-printed objects generated using photopolymer resin. Various arrangements and designs of microstructures on the surface of 3D-printed objects were examined. Leveraging the superior resolution of stereolithography printers (SLA) over fused deposition modeling, intricate microfeature designs were well-implemented. The experiments involved a range of structures on the surface of the 3D-printed objects, including precisely defined arrays of microcylinders, microchannels, and other complex designs generated by parametric equations. The hydrophobicity of the 3D-printed objects was assessed through the water droplet test, revealing a spectrum of results ranging from hydrophobic to weakly hydrophobic, and to hydrophilic surfaces. Light microscopy was employed to characterize the surface morphological properties of the 3D-printed objects, which were then correlated with the measured contact angles. It was discovered that the 3D-printed objects with microstructures formed using parametric functions exhibited patterns with irregularities and fluctuations along all directions or axes, resulting in a higher degree of hydrophobicity compared to structured matrices with pillared arrays. However, some surfaces created with parametric functions resulted in an anisotropic system where the material properties varied along one direction, while the other direction exhibited a flat, planar surface. These anisotropic systems were found to be less hydrophobic according to the water droplet test. [ABSTRACT FROM AUTHOR]

Nanoscale oxides grown in c-silicon, implanted with low-energy (2 keV) H+ ions and fluences ranging from 1013 cm−2 to 1015 cm−2 by RF plasma immersion implantation (PII), have been investigated. The oxidation of the implanted Si layers proceeded in dry O2 at temperatures of 700 °C, 750 °C and 800 °C. The optical characterization of the formed Si/SiOx structures was conducted by electroreflectance (ER) and spectroscopic ellipsometric (SE) measurements. From the ER and SE spectra analysis, the characteristic energy bands of direct electron transitions in Si are elaborated. The stress in dependence on hydrogenation conditions is considered and related to the energy shifts of the Si interband transitions around 3.4 eV. Silicon oxides, grown on PII Si at a low H+ fluence, have a non-stoichiometric nature, as revealed by IR-SE spectra analysis, while with an increasing H+ fluence in the PII Si substrates and/or the subsequent oxidation temperature the stoichiometric Si-O4 units in the oxides become predominant. The development of surface morphology is studied by atomic force microscopy (AFM) imaging. Oxidation of the H+-implanted Si surface region flattens out the surface pits created on the Si surface by H+ implants. Based on the evaluation of the texture index and mean fractal dimension, the isotropic and self-similar character of the studied surfaces is emphasized. [ABSTRACT FROM AUTHOR]

Temporary anchorage devices (TADs) are orthodontic mini-implants with remarkable characteristics that, once inserted, present mechanical retention (primary stability) without the process of bone osseointegration. However, interaction with the biological environment may cause changes in the morphology of the external surface of dental TADs. In this study, we used 17 TADs made of aluminum–vanadium titanium alloy, produced by two companies, which were analyzed through optical microscopy after being removed from the patients during orthodontic treatment. We evaluated the changes that appeared on the TADs' surfaces after their use in the biological environment, depending on the morphological area in which they were inserted. In our study, we found changes in the morphology of the implant surface, and especially deposits of biological material in all study groups. On all samples examined after clinical use, regardless of the period of use, corrosion surfaces in different locations were observed. Our obtained results support the idea that the biological environment is aggressive for mini-implant structures, always producing changes to their surface during their clinical use. [ABSTRACT FROM AUTHOR]

Nanoparticles of barium zirconate were prepared by sol–gel method and used for the preparation of nanocomposites. Polyaniline fibers and its nanocomposites with barium zirconate were prepared by in‐situ polymerization at various percentages of 1 wt%, 2 wt%, 3 wt%, 4 wt%, and 5 wt%. The prepared polyaniline nanocomposites were subjected for determination functional group by FTIR spectra and XRD analysis. The surface morphology is important aspect of sensor studies, which is illustrated by SEM and TEM image. DC conductivity of the pristine PANI and its nanocomposites increases with increase in temperature up 200°C. It is evident that the increase in conductivity is due to the hopping of charge carriers from valence band to conduction band. Among all the nanocomposites, 3 wt% of polyaniline nanocomposite shows the high conductivity of 18.6 S/cm. It is also noted that 3 wt% polyaniline nanocomposites have a higher sensitivity of 86.2% at 300 ppm when compared with other compositions. This could be because of formation strong connections between the polyaniline fibers and nano‐oxide as a resulted of enhanced node connections, high surface area and porosity through optimized nanomaterials doping. The nanocomposites sensitivity restored in 89 s after the gas was removed, responding in 23 s at 300 ppm. [ABSTRACT FROM AUTHOR]

Pineapple peel waste has high bioactivity in the form of polyphenols and flavonoids; therefore, in the current research, valorization of agro-processing waste of pineapple peel was carried out to extract BAC using the Microwave-assisted extraction (MAE) method as a green technology.Herniarin, the targeted BAC from pineapple peel extract, was identified and isolated using HRLC-MS/MS and measured using HPLC. Lipophilic liposomes made by ethanol injection technique using Phosal 50 PG encapsulated heriarin (7-Methoxy coumarin); the formulations were analysed for size distribution, entrapment efficiency, and surface morphology. To stabilise the produced formulation, liposomes were freeze dried with mannitol as a cryoprotectant. During a six-month stability investigation, the entrapment efficiency of lyophilized liposome ranged from 99.74 ± 0.24 to 91.56 ± 0.34. Cookies were prepared in concentrations of 0.5%, 1.0%, and 1.5% herniarin (with and without encapsulation) to determine the effect of antioxidant activity, physicochemical, and microbial properties after 3 months of storage. Cookies with encapsulated BAC (MCNWE) had free fatty acid values ranging from 0.21 ± 0.08 to 1.00 ± 0.04, and antioxidant capacity ranging from 18.02 ± 0.04 to 13.98 ± 0.05.It can be inferred that cookies with encapsulated BAC have the highest antioxidant capacity and can be used as functional food with fair overall acceptability in market. [ABSTRACT FROM AUTHOR]

This study investigated the synergistic impact of montmorillonite (MMT) and starch nanocrystals (SNCs) on gluten-loaded chitosan films, influencing the shelf stability of fresh paneer. The combination of chitosan in gluten and SNCs/MMT yielded films with uniform rheology, showcasing superior water resistance, mechanical strength, surface morphology, and antioxidant properties. Notably, compared to unpackaged paneer, those wrapped in these nanocomposite films exhibited an extended shelf life. Films produced from MMT/chitosan (GML2) retained higher moisture (68.37 to 53.12%) and titratable acidity (0.17 to 2.12%) compared to other samples. Consequently, textural properties, including hardness, springiness, chewiness, and gumminess, correlated with moisture loss, affirming the wholesomeness of paneer packaged in GML2, followed by SNCs/chitosan (GSL2). The longer shelf-life of paneer was co-related with minimal increase in free fatty acids and tyrosine content of GML2 and GSL2, lead reduced lipolysis and proteolysis. The microbiological analysis demonstrated the resilience of paneer in GML2 and GSL2, with total yeast/mold count (4.00 logCFU/g and 5.00 logCFU/g) and total plate count (6.00 logCFU/g and 6.00 logCFU/g) maintained up to the 12th day. Overall, physico-chemical attributes confirmed the superior physical and nutritional quality of paneer packaged in GML2 and GSL2 compared to the control, effectively preserving its freshness for 12 days. Highlights: Gluten-based films reinforced with MMT/chitosan and SNCs/chitosan were developed. Novel Gluten-based Bionanocomposites enhance the shelf stability of Paneer. MMT/chitosan and SNCs/chitosan demonstrated textural stability in Paneer. Bionanocomposites preserved paneer in fresh condition for up to 12 days. [ABSTRACT FROM AUTHOR]

Ultra-precision machining has higher requirements for the performance of abrasive tools, but the traditional grinding wheel has some problems such as irregular grain arrangement, limited chip space, and high grinding temperature. Therefore, a structured grinding wheel suitable for ultra-precision machining is proposed. In this study, the laser cladding method and ultrasonic vibration technology were combined to study the preparation process of a structured grinding wheel. Firstly, the quality evaluation system of the printing layer was established, and the shape coefficient and dilution rate were used to evaluate the laser cladding quality. The effects of laser power, sweep speed, powder feeding speed, and ultrasonic power on the shape coefficient and dilution rate of the printing layer were analyzed by single-factor experiments. The level range of each factor in the orthogonal experiment was established to optimize the process parameters. The surface morphology was observed, and the influence of ultrasonic vibration on the morphology was analyzed. The structured grinding wheel was prepared according to the optimized parameters. [ABSTRACT FROM AUTHOR]

The aim of present work was to develop and evaluate Ampelopsis Radix ethanolic extract loaded phytosomes for improved efficacy in colorectal cancer. Ampelopsis Radix ethanolic extract was prepared by Soxhlet extraction process followed by development of phytosomes using lipids and other excipients. The phytosomes were evaluated for surface morphology, particle size analysis, zeta potential, encapsulation efficiency, drug loading, in vitro drug release, Cytotoxicity assay, cellular uptake studies were performed on HCT-116 and SW480 cell lines. In vivo antitumor activity was performed. The phytosomes were found spherical shape with smooth surface characteristics. The drug loading was observed between 29.27 to 42.10 % while particle size of 85 to 130 nm was found. Phytosomes showed desired release pattern which is required for cancer treatment. Phytosomes showed maximum antiproliferative activity on cell lines over the period of 24 hours and showed highest internalization within both types of cell lines. The survival rate of animals in phytosomes treated group was found to be 100% proving the safety and efficacy. Phytosomes showed highest antitumor activity as compared to other formulations. Study confirms the potential use Ampelopsis Radix ethanolic extract loaded phytosomes for improved efficacy in colorectal cancer. [ABSTRACT FROM AUTHOR]

In this investigation, the factors were oil type ( O t ), powder type ( T p ), and powder concentration ( C p ) level, and the machining parameters were the voltage (V), capacitance (pf), pulse-on time ( T on ), and pulse-off time ( T off ). The output parameters were the material removal rate (MRR), and tool wear rate (TWR). Three types of oils and powders, along with their respective particle concentrations, were selected for this experiment. Neem, Karanja, and sesame oils were mixed with aluminum oxide (Al2O3), chromium (Cr), and nickel (Ni) powder at 4, 6, and 8 gm/l, respectively, using an overhead stirrer to investigate the conditions under which the green oil powder mixed mixture yielded a higher MRR and lower TWR during the micro-EDM process of titanium alloy (Ti-6Al-4V) using a 0.8 mm tungsten carbide (WC) tool with fixed machining parameters (240 V, 100 pf, 20 μ s T on , and 5 μ s T off ). All the powders used in this experiment had a 32-micron (450 mesh) size. The Taguchi L 2 7 orthogonal array and grey relational analysis methods were used to design and optimize the input process parameters for both responses. SEM, optical microscopic analysis, and EDS analysis were performed to examine the surface morphology, characteristics of the WC tool, and elemental composition of both the tool and the workpiece material. The optimum conditions for Karanja oil with a Cr powder mixture concentration of 4 g/l resulted in higher MRR and lower TWR. However, machining with neem and sesame oils resulted in higher TWR and lower MRR. [ABSTRACT FROM AUTHOR]

The mixing of N3 and N719 metal-complex dyes was investigated in this work to determine the effects of the combination of dyes on TiO2film for application in dye-sensitized solar cells (DSSCs). The dyes were mixed in a ratio of 1:1, and their performance in the DSSCs was measured using current–voltage curves and electrochemical impedance spectroscopy (EIS). The results indicated that the efficiency of the DSSCs increased to 7% with the addition of the N719 dye to the N3 dye. The surface morphology revealed a smooth and homogeneous distribution of TiO2 nanoparticles, and the mixed dyes showed broad absorption spectra in the visible region. The EIS results indicated a low electron recombination rate and long electron lifetime for the mixed dye-sensitized solar cells. Overall, the study demonstrated the potential for using a combination of N3 and N719 dyes to improve the efficiency of DSSCs. The employment of mixed dye as a photosensitizer in DSSCs may offer a promising approach for achieving high-performance and cost-effective DSSCs. [ABSTRACT FROM AUTHOR]

In this study, shot peening (SP), quenching and tempering (QT) heat treatment, baking heat treatment and Cr-plating technologies were used to enhance the hardness, tribological properties and corrosion resistance of AISI 4340M steel. The purpose of this study is to develop repair process technology for an overhaul of landing gear applied to the MRO process and establish a quality assurance system. The effects of SP, QT heat treatment, Cr-plating, stripping after Cr-plating and Cr-plating after stripping and re-SP on the tribological properties and corrosion resistance of AISI 4340M steel were investigated, and the obtained results were compared with the base AISI 4340M steel. One of the reasons for stripping after Cr-plating is to find out how many times stripping can be done after Cr-plating. Moreover, it is important to investigate the effect of re-SP after Cr-plating on the tribological properties and corrosion resistance. The tribological properties of the specimens were investigated using a ball-on-disk tribometer at room temperature against AISI 52100 steel for 60 min under dry conditions. The corrosion resistance was investigated using a potentiodynamic polarization test in NaCl 3.5% solution. The results showed that the application of SP, QT heat treatment, Cr-plating, stripping after Cr-plating and Cr-plating after stripping and re-SP had a significant effect on the tribological properties and corrosion resistance of AISI 4340M steel. The effects of SP and Cr-plating post-treatment technologies on the wear and corrosion enhancement and mechanisms were discussed based on the microstructural and surface morphology of worn and corroded surfaces. [ABSTRACT FROM AUTHOR]

This study introduces an innovative approach by modifying a commonly used filler with a natural compound, PEI. Fine aggregates within the filler were treated with different contents of PEI solutions. This research thoroughly examined the filler's pore structure, mineral composition, physical characteristics, and surface morphology. Additionally, this study explored the effects of PEI-treated fine aggregates on the macroscopic features of recycled cement mortar, focusing on aspects like flowability, compressive strength, capillary water absorption, and chloride ion permeability. The findings revealed that treating the fine aggregates with PEI decreased the pore volume by up to 28.2% compared to untreated samples. This improvement in the microstructure may originate from the formation of calcite and its by-products, which occupy the pores with nanoparticles generated in situ. Furthermore, the modification with polyethyleneimine resulted in a wavy, plate-like structure that not only enhanced the surface morphology but also improved the compressive strength and chloride ion permeability. Furthermore, it significantly reduced capillary water absorption by 32% to 51%, thereby enhancing the material's durability. The present study underscores the superior advantages of PEI modification as a promising strategy to enhance the viability of public fine aggregates. [ABSTRACT FROM AUTHOR]

In the current scenario, industries face new challenges in cutting metal-based composites with good surface texture. The experimental investigation on laser cutting of magnesium AS2-Bimodal SiC composites is reported in the present work. Three bimodal compositions with varying proportions of micro-nano SiC reinforcement (75%-25%, 50%-50% and 25%-75%) were dispersed in AS21 alloy by stir-casting route. The comparison of quality characteristics such as surface roughness, kerf deviation and edge slope has been done to examine the behaviour of bimodal reinforcement with different laser cutting parameters. The experimental strategy was implemented based on the Taguchi L18 mixed design. The microstructure and cutting surface morphology has been analysed using OM, SEM and TEM. The results demonstrated that the AS21 composite with a bimodal structure of 75 vol.% micro-SiC and 25 vol.% nano-SiC showed better performance characteristics of CO2 laser cutting system due to uniform grain structure and homogeneous dispersion of nano-SiC reinforcement. [ABSTRACT FROM AUTHOR]

In order to improve the wear resistance of copper and enhance the surface properties of copper parts, this article uses BN nanoparticles as a reinforcing phase and the laser remelting method to prepare a Cu/BN remelted layer on the copper surface. The surface morphology, crystal structure, microhardness, and wear resistance of the samples were tested and characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), a microhardness tester, and a friction and wear tester. The effects of laser frequency, pulse width, and energy density on the surface morphology and wear resistance of the samples were analyzed and studied, and the effects of the laser parameters on the properties of the Cu/BN remelted layer were discussed. The research results indicate that laser frequency, pulse width, and energy density have a direct impact on the surface morphology and properties of the Cu/BN remelted layer, but the impact mechanism by the above parameters on the remelted layer is different. The effects of laser frequency on the remelted layer are caused by changes in the overlap mode of the remelting points, while laser pulse width and energy density are achieved through changes in remelting intensity. When the laser frequency is 10 Hz, the pulse width is 10 ms, and the energy density is 165.8 J/mm2, the Cu/BN remelted layer has better surface properties. [ABSTRACT FROM AUTHOR]

In order to study the feasibility of forming microtexture at the surface of 7050 aluminum alloy by laser-induced cavitation bubble, and how the density of microtexture influences its tribological properties, the evolution of the cavitation bubble was captured by a high-speed camera, and the underwater acoustic signal of evolution was collected by a fiber optic hydrophone system. This combined approach was used to study the effect of the cavitation bubble on 7050 aluminum alloy. The surface morphology of the microtexture was analyzed by a confocal microscope, and the tribological properties of the microtexture were analyzed by a friction testing machine. Then the feasibility of the preparation process was verified and the optimal density was obtained. The study shows that the microtexture on the surface of a sample is formed by the combined results of the plasma shock wave and the collapse shock wave. When the density of microtexture is less than or equal to 19.63%, the diameters of the micropits range from 478 μm to 578 μm, and the depths of the micropits range from 13.56 μm to 18.25 μm. This shows that the laser-induced cavitation bubble is able to form repeatable microtexture. The friction coefficient of the sample with microtexture is lower than that of the untextured sample, with an average friction coefficient of 0.16. This indicates that the microtexture formed by laser-induced cavitation bubble has a good lubrication effect. The sample with a density of 19.63% is uniform and smooth, having the minimum friction coefficient, with an average friction coefficient of 0.14. This paper provides a new approach for microtexture processing of metal materials. [ABSTRACT FROM AUTHOR]

The current investigation focuses on the viscosity, coating weight, and surface characteristics of lost foam casting coatings, examining the effects of blade shape, stirring speed, and stirring time. A systematic analysis was conducted to determine how different stirring speeds and durations influenced coating weight and viscosity. The results indicate that the blade shape has a considerable impact on the uniformity and efficacy of the coating, with some designs being far more effective in reaching the optimal viscosity and coating weight through uniformly distributed mixing. Results were consistently obtained when stirring at 800–1200 rpm. It was demonstrated that while stirring speed significantly impacts coating deposition, it has small effect on viscosity. A stirring time of 30 min was found optimal for stabilizing coating weight and viscosity without significant variations. Drying at room temperature produced smoother surfaces with fewer cracks, whereas higher drying temperatures (50 °C) were associated with increased surface roughness and cracking. Crack analysis after drying revealed that coatings mixed with the tri-blade had the lowest tendency to crack, demonstrating its superior capability for even and thorough mixing. [ABSTRACT FROM AUTHOR]

This study explores the effects of the powder-to-liquid ratio on the performance characteristics of lost foam casting coatings. The investigation focuses on how variations in this ratio affect key properties, including apparent viscosity, shear thinning behavior, coating weight, and surface morphology. Through a series of controlled experiments, coatings were prepared with different powder-to-liquid ratios and assessed for their physical and application properties. The results indicate that increasing the powder-to-liquid ratio raises the apparent viscosity and modifies shear thinning behavior. Notably, ratios exceeding 2.0 result in a sharp increase in viscosity that impedes coating application. The optimal powder-to-liquid ratio was determined to be between 2.0 and 2.2, where coatings demonstrated enhanced uniformity, improved particle distribution, and superior surface morphology. Coating weight increased up to a ratio of 2.2 but decreased beyond this threshold due to excessive viscosity. Both microscopic and macroscopic analyses confirmed that a ratio of 2.0 to 2.2 strikes the best balance for coating performance. These findings underscore the importance of precise powder-to-liquid ratio control to optimize the quality of lost foam casting coatings, offering valuable insights for refining coating formulations and application techniques in industrial contexts. [ABSTRACT FROM AUTHOR]

Tingui biochar (TB) activated with potassium hydroxide (TB-KOH) was synthesized in the present study. The adsorption capacity of TB-KOH was evaluated for the removal of acetaminophen and caffeine in monocomponent and bicomponent solutions. As a result, the study of the TB-KOH characterization as well as the adsorption kinetics, isotherm, thermodynamics, and a suggestion of the global adsorption mechanism are presented. TB-KOH was characterized through physical–chemical analysis to understand its surface morphology and how it contributes to the adsorption of these drugs. Furthermore, modelling using advanced statistical physical models was performed to describe how acetaminophen and caffeine molecules are adsorbed in the active sites of TB-KOH. Through the characterizations, it was observed that the activation with KOH contributed to the development of porosity and functional groups (-OH, C-O, and C = O) on the surface of TB. The monocomponent adsorption equilibrium was reached in 90 min with a maximum adsorption capacity of 424.7 and 350.8 mg g−1 for acetaminophen and caffeine, respectively. For the bicomponent solution adsorption, the maximum adsorption capacity was 199.4 and 297.5 mg g−1 for acetaminophen and caffeine, respectively. The isotherm data was best fitted to the Sips model, and the thermodynamic study indicated that acetaminophen removal was endothermic, while caffeine removal was exothermic. The mechanism of adsorption of acetaminophen and caffeine by TB-KOH was described by the involvement of hydrogen bonds and π-π interactions between the surface of TB-KOH and the molecules of the contaminants. [ABSTRACT FROM AUTHOR]

Silicon carbide particle–reinforced aluminum matrix (SiCp/Al) composite materials are challenging to machine, leading to significant surface quality issues arising during milling. In this study, a single-factor experiment was conducted using carbide-coated tools to mill SiCp/Al composite materials with a 45% volume fraction of silicon carbide particles (SiCps). Scanning electron microscopy, roughness measuring instruments, and a three-dimensional optical profiler were employed to investigate the formation mechanisms of the machined surface morphologies, as well as the effects of milling parameters (milling speed, feed per revolution, and milling depth) on the surface micro-morphology of the SiCp/Al composite materials. This study assessed the suitability of various roughness characterization parameters for evaluating the milled surface of SiCp/Al composite materials, including the two-dimensional profile arithmetic mean deviation (Ra), profile root mean square deviation (Rq), and microscopic surface roughness 10-point height (Rz), as well as the three-dimensional arithmetic mean deviation of the surface profile (Sa), and root mean square deviation of the surface profile (Sq) roughness characterization parameters to evaluate the milled surface of the SiCp/Al composite materials. The findings suggest that the three-dimensional roughness characterization parameters more accurately reflected the changes in the surface roughness than the two-dimensional ones. When the milling speed increased from 0.05 to 1.2 mm/rev, Sa first decreased from 0.514 to 0.498 µm and then increased to 0.537 µm, while Sq first decreased from 0.637 to 0.616 µm and then increased to 0.658 µm. Ra, Rz, and Rq all increased with higher values of feed per revolution and milling depth. [ABSTRACT FROM AUTHOR]

The study of chip morphology during high-speed milling is crucial in determining processing quality, but the relationship between chip formation mechanisms and process parameters in titanium alloy high-speed machining has been a difficult issue. This paper investigates milling force and temperature variation, as well as chip morphology and surface quality after milling to improve workpiece surface quality and machining efficiency and provide guidance on selecting milling parameters. Factorial analysis confirms that milling speed worsens the serrated layer of chips. In addition, the experiment confirms the influence of tool rake angle on shear strain in the milling zone, the impact of rotational speed on tool wear, and the effect of tool wear on chip morphology. The results show that increasing milling speed worsens chip serration and increases tool wear. [ABSTRACT FROM AUTHOR]

To know the sustainable performance of calcium-based adsorbents is one of the important aspects to realize efficient and economical carbon capture, and to systematically study the properties of natural adsorbents is conducive to their industrialization. The cyclic calcination and carbonation characteristics of a typical natural limestone were investigated using a thermal gravimetric analyzer. Two kinds of over-sintering conditions were selected to emphatically study the cyclic separation of CO2 from limestones through prolonging the calcination time and increasing the calcination temperature. The results showed that the untimely end of the chemical reaction control stage caused by excessive sintering is the direct reason for the reduction in cyclic carbonation conversion, and the changes in surface morphology of calcined products due to pore collapse and fusion are the fundamental reasons for the reduction in cyclic carbonation conversion. The excessive sintering caused by extending the calcining time or increasing the calcining temperature has great inhibition on this cycle only; the inhibition decreases rapidly in subsequent cycles. In addition, SEM and BET–BJH tests further confirm the influence of the over-sintering phenomenon. With the further increase in cycle number, the early excessive sintering has certain stimulative effects on the subsequent carbonation reaction. It is expected to provide a reference for the subsequent research and development of natural calcium-based adsorbents. [ABSTRACT FROM AUTHOR]

Semiconducting metal oxides are widely used for solar cells, photo-catalysis, bio-active materials and gas sensors. Besides the material properties of the semiconductor being used, the specific surface topology of the sensors determines device performance. This study presents different approaches for increasing the sensing area of semiconducting metal oxide gas sensors. Micro- and nanopatterned laser-induced periodic surface structures (LIPSSs) are generated on silicon, Si/SiO2 and glass substrates. The surface morphologies of the fabricated samples are examined by FE SEM. We selected the nanostructuring and characterization of nanostructured source Ni/Au and Ti/Au films prepared on glass using laser ablation as the most suitable of the investigated approaches. Surface structures produced on glass by backside ablation provide 100 nm features with a high surface area; they are also transparent and have high resistivity. The value of the hydrogen sensitivity in the range concentrations from 100 to 500 ppm was recorded using transmittance measurements to be twice as great for the nanostructured target TiO2/Au as compared to the NiO/Au. It was found that such transparent materials present additional possibilities for producing optical gas sensors. [ABSTRACT FROM AUTHOR]

One of the main goals of jewelry is to give the product an aesthetic and artistic look. This can be achieved by changing its color. The promising methods of precious metal coloration is a one-step laser method of forming nanostructures with plasmonic properties. However, the lack of understanding of the mechanism of formation of color coatings remains an unresolved problem today. Surface structures are usually considered as a set of individual spherical nanoparticles. But to fully understand the physicochemical processes taking place, it is necessary to consider nanoparticles in aggregate as agglomerates of these nanoparticles on the surface. The silver samples of 99.99 % purity were selected for the study. Laser exposure was carried out in air using a system based on an ytterbium fiber laser with nanosecond pulse duration. The silver surface was processed by line-by-line scanning along one and two axes with a focused laser beam with the diameter d0 = 50 μm. Optical and scanning electron microscopy were used to characterize the silver surface before and after laser treatment. In this work, the effect of some laser exposure parameters, such as laser pulse energy and pulse repetition rate, on the optical properties of silver surface were investigated. The focus of this work is on generated laser-modified surface nanostructures and the character of their change when going from single axis scanning to line scanning. It is shown that surface topography changes are also observed in the region outside the immediate treatment zone. The uneven distribution of nanostructural elements on the surface of the treated area is registered, which causes the irregularity of the observed surface color at the microlevel. Based on the analysis of the obtained data, a hypothesis of nanostructure formation is proposed. Under laser exposure, individual spherical-shaped nanoparticles are initially formed on the silver surface. Then with increasing temperature their concentration increases significantly. This leads to their adhesion and formation of irregularly shaped clusters of agglomerated nanoparticles. The obtained new data on the process of formation of surface nanostructures allow us to expand the understanding of the ongoing processes, as well as to approach the integration of the method of direct laser coloring of silver in the jewelry industry.

In the production of transition metal nitride hard coatings under specific deposition conditions, the resulting residual stresses play a critical role in determining the mechanical properties, adhesion, and overall performance of the coatings. In this work, an artificial neural network (ANN) that utilizes feed-forward architecture is used to predict the average residual stress in titanium nitride (TiN) coatings with different coating thickness. These coatings are manufactured under varying bias voltages and temperature on substrate. The impact of variations in coating thickness, bias voltage, and temperature on development of internal residual stresses and changes in microstructure within sputtered coatings have been gathered from existing literature. The data collected is within the context of fibrous (zone I) and mix columnar and fibrous structure (combined zone) as defined by an existing structure zone model. The model is trained with experimental data from literature. The model is trained with experimental data from literature. The validation of the ANN model is carried out by comparing the predictions with experimental results. X-ray diffraction is used to analyze the residual stresses, preferred orientation, and the structure (zone I and combined zone) of produced coatings under different sputtering parameters. The regression and performance curves are used to assess the efficacy of ANN model. The coefficient of determination of trained model and mean square error are 0.9918 and 0.35, respectively. The predicted results show good agreement with experimental and subsequently AFM grain morphology analysis captures the growth mechanisms involved in the residual stresses evolution.

Metallic components with surface microfeatures are increasingly used in aerospace, automotive and other applications due to their drag-reducing properties. In this situation, we proposed a novel shape-surface integrated incremental sheet forming (S2-ISF) process to achieve the simultaneous fabrication of both surface microfeatures and desired geometric shape. It was found that an increase in the forming angle was most effective in improving the formation of microgroove array, followed by the step size, the spindle speed and the feed rate. Moreover, when the forming angle is constant, the step size and microgroove pitch increase linearly. Compared to the as-received sheet, the yield strength is increased by more than 20% after the S2-ISF process. Moreover, we observed that the increase of forming angle in the S2-ISF process has promoted grain deformation and grain fragmentation, which is favorable for the formed part to obtain more uniform and finer grains. The grain size distribution along the thickness direction shows the characteristics of ‘coarse in the middle and fine at both ends’. Finally, we found that the formed parts with different microgroove pitch from the S2-ISF process have the significant enhancement on the hydrophobicity and anti-friction property. When microgroove pitch is 155.5 μm, the surface contact angle of formed part improved from 70.65° to 101.39°, and the wear volume of formed part decreases from 4.89 × 10−3 mm3 to 3.65 × 10−3 mm3. This work provides a solution for the efficient and economical fabrication of three-dimensional thin-walled parts with microgroove array to enhance surface functionality.

The aim of the paper was to determine electrochemical deposition conditions for superhydrophobic and superhydrophilic copper coatings on copper substrates. Through variable conditions of the two-stage electrodeposition process (cathode overpotential, process duration), copper layers with different wettability, i.e. high 150° and low contact angle 8°, were created. In particular, low wettability was achieved in the electrodeposition process involving low overpotential and long process time in the first stage, and high overpotential and short process time in the second stage. However, high wettability was obtained for stage I, including low overpotential and long time, and stage II, for low overpotential and long time. The morphology of the hierarchical layers was analyzed using a scanning electron microscope. The experiment suggests that the electrodeposited copper surface can exhibit stable wettability in real applications.

[Display omitted] • The performance and stability of different anionic salts in 2G for HC/Na half-cells are investigated. • The interfacial chemistry, interphasial properties and electrochemical kinetics are comprehensively studies. • The underlying side reaction and mechanism of different anionic salts with Na metal is elucidated. In hard carbon (HC) anodes, elucidating the relationship between the solid electrolyte interphase formation and the solvated Na+ co-intercalation mechanism is crucial, particularly considering different anionic salts in ether-based electrolytes. Here, we comprehensively explore the impact of different anionic salts on the electrochemical performance of HC/Na half-cell and elucidate the underlying mechanism through experimental studies and theoretical calculations. The surface morphology of the HC anode and its interphasial property are further investigated to evaluate the differences endowed by the presence of various anionic salts in diglyme (2G). The HC/Na half-cells with NaPF 6 -2G and sodium trifluoromethanesulfonate (NaCF 3 SO 3)-2G display superior electrochemical performance with faster kinetics and lower interfacial resistance than those with NaClO 4 -2G, sodium bis-(fluorosulfonyl) imide (NaFSI)-2G and sodium bis-(trifluoromethanesulfonyl) imide (NaTFSI)-2G. NaClO 4 -2G forms a relatively thick interphase layer with high resistance at the electrode/electrolyte interface owing to its insufficient stability. NaFSI-2G and NaTFSI-2G exhibit severe side reactions with Na metal, producing a thick interphase layer on the HC surface with high interfacial resistance from excess electrolyte decomposition, thus deteriorating the electrochemical performance. In summary, the study on the stability of different anionic salts in ether-based electrolyte for the HC anode with the intercalation mechanism provides valuable insights for screening appropriate conductive salts for high-performance sodium-ion batteries, especially when considering Na metal counter/reference electrodes. [ABSTRACT FROM AUTHOR]

In this work, we demonstrated the role of shallow energy level defect states on the emission of CH3NH3PbBr3 perovskite polycrystals under laser excitation. The perovskite polycrystals were synthesized by a simple, one-step, low-cost solution self-assembled method. By adjusting the sample preparation temperature from 303 to 373 K, we could manipulate the number of shallow energy level defect states, which were evaluated through low-temperature photoluminescence measurement. This led to an evolution of the CH3NH3PbBr3 perovskite polycrystals' emission from amplified spontaneous emission to random lasing emission. As a result, the most efficient lasing threshold of 4 μ J mm−2 was achieved with the CH3NH3PbBr3 perovskite polycrystals synthesized at the optimum temperature of 333 K. Furthermore, the surface morphologies and the crystal structure of the CH3NH3PbBr3 perovskite polycrystals were also taken into consideration to unravel the role of defects in the CH3NH3PbBr3 perovskite polycrystals. [ABSTRACT FROM AUTHOR]

An intricately designed one-pot hydrothermal approach was utilized to synthesize yolk-shelled Co 3 Fe 1 glycerate, demonstrating its role as a highly efficient electrocatalyst for the oxygen evolution reaction. [Display omitted] • A convenient method to synthesize a range of CoFe gly with controllable surface morphologies. • The yolk-shell structure of Co 3 Fe 1 gly ensures uniformly distributed active sites, promoting efficient mass transfer. • Co 3 Fe 1 gly shows great potential for advancing electrode material development. CoFe-based catalysts are efficient electrocatalysts for the oxygen evolution reaction (OER) in alkaline media. Here, we present a simple one-pot hydrothermal method for synthesizing a series of CoFe glycerates with controllable surface morphologies and investigate their potential as highly efficient catalysts for the OER in alkaline media. These CoFe glycerates exhibit a unique yolk-shell microsphere structure assembled from ultrathin nanosheets. The adjustment of the surface nanosheet size is achieved by varying the CoFe ratio, ensuring a more efficient electrocatalytic system for the OER process. Due to the abundant active sites provided by the yolk-shell structure and interleaved ultrathin nanosheets, Co 3 Fe 1 glycerate (Co 3 Fe 1 gly) demonstrates a low overpotential (283 mV) and a small Tafel slope (44.61 mV dec−1) at 10 mA cm−2. Additionally, Co 3 Fe 1 gly exhibits excellent durability in alkaline electrolytes. Moreover, a series of characterizations demonstrate that the active sites of Co 3 Fe 1 gly are the high-valence Co species generated during the OER process. This study opens a promising avenue for utilizing efficient and low-cost electrocatalysts to enhance OER performance. [ABSTRACT FROM AUTHOR]

The interfacial nature of the electric double layer (EDL) assumes that electrode surface morphology significantly impacts the EDL properties. Since molecular-scale roughness modifies the structure of EDL, it is expected to disturb the overscreening effect and alter differential capacitance (DC). In this paper, we present a model that describes EDL near atomically rough electrodes with account for short-range electrostatic correlations. We provide numerical and analytical solutions for the analysis of conditions for the overscreening breakdown and DC shift estimation. Our findings reveal that electrode surface structure leads to DC decrease and can both break or enhance overscreening depending on the relation of surface roughness to electrostatic correlation length and ion size asymmetry.   [ABSTRACT FROM AUTHOR]

Sulphate ions removal from Acid mine drainage (AMD) is crucial to mitigate its adverse impact on aquatic and terrestrial ecosystem. Similarly, surplus and unused quantity of the Fly ash, waste from coal-based power plants is also challenging problem. In the present study, Fly ash based low-cost adsorbents (NaOH at 100 oC and HCL at 400 oC) activated Fly ash were synthesized using thermal activation methods. The composition and surface morphology studies were conducted using FTIR, XRD, XRF and SEM-EDX analysis. The Synthesized adsorbents were used to removal of sulphatic ion under various experimental conditions such as initial concentration (5 to 50 mg L−1), contact time (0 to 180 minutes), dose (5 to 40 mg L−1), solution pH (4.5, 5 and 5.5 pH). The optimum removal was 63 ± 1.4 % and 65 ± 1.6 % at room temperature 27 °C, pH 5.5 and 0.6 g L−1 dose of FAZ-HCl and FAZ-NaOH adsorbents respectively. The kinetics models and adsorption isotherm were determined to be pseudo second order (R2 > 0.9919) for FAZ-HCl and pseudo first order which (R2 > 0.9857) was validated and fitted by Freundlich isotherm (R2 > 0.9806 and 0.9932) for FAZ-HCl and FAZ-NaOH. [ABSTRACT FROM AUTHOR]

Stainless steel codeposition on a low-cost substrate is crucial because of economic factors. In this work, codeposition of FeCrNi thin film was successfully prepared galvanostatically from a novel environmentally friendly mixed complex (glycine-formate) bath on a steel surface. The novel bath is characterized by using environmentally benign Cr(III) rather than Cr(IV), at pH 7, applying low current density (id) at 25 °C, and finally producing crack-free nanostructured FeCrNi films with up to 18% Cr. The obtained FeCrNi thin film has a composition resembling that of stainless steel 304 (Ni 8% and Cr ~ 18%). The study was carried out using potentiodynamic polarization curves, chronoamperometric analysis, and anodic linear stripping voltammetry (ALSV), complemented by a scanning electron microscope and X-ray diffraction analysis. The atomic absorption test showed an acceptable range of Cr content (from 13.76 to 18.75 At. %) depending on the practical circumstances. The Cr% is enhanced slightly by decreasing the id and pH or raising the temperature. At deposition times of 20 and 60 min, the Cr content slightly decreased with increasing id. For example, the Cr content decreased from 17.88% (at 0.48 mA cm−2) to 13.98% (at 2.41 mA cm−2) and decreased from 17.14% (at 0.48 mA cm−2) to 13.94% (at 2.41 mA cm−2) respectively. The deposition of FeCrNi films has been characterized by instantaneous nucleation followed by 3D growth under charge transfer control. The phases were polycrystalline, and their grain size value was 8.93 nm. At a relatively high current density (2.41 mA cm−2), the coatings' surface morphology became uniform, extremely smooth, and nearly devoid of micro-cracks. However, a low bath pH of 4.0 results in observed multiple pits of varying sizes. [ABSTRACT FROM AUTHOR]

Extensive research efforts have been focused on customizing the microstructure, macrostructure, and phase composition of calcium phosphate for enhanced biocompatibility and bioactivity in scaffolds for bone substitutes. Despite significant progress, achieving precise phase composition and microstructure remains a challenge, primarily due to the necessity of scaffold sintering. This study addresses the challenges in developing customized patient‐specific bone substitutes by proposing a sequential approach that reduces processing steps while providing control over the phase and morphology of the scaffolds' structure. The methodology utilizes freeze‐casting and sintering for highly porous the scaffolds' preparation, followed by hydrothermal treatment to modify the microstructure. The introduction of CaCO3 induces a phase transformation of tricalcium phosphate, increasing the hydroxyapatite content, while the overall macrostructure retains the characteristics of freeze‐casting. The surface morphology undergoes a transition from equiaxial grains to whiskers‐like structures and hexagonal rods, impacting compressive strength. Following hydrothermal treatment, the formation of whiskers‐like hydroxyapatite grains leads to a notable strength increase from 2.8 to 5.7 MPa. Remarkably, the scaffolds undergo nearly complete phase transformation, shifting from 100% tricalcium phosphate to 99% hydroxyapatite, all while conserving the macrostructure. [ABSTRACT FROM AUTHOR]

Many industrial components, especially those realized through 3D printing undergo surface finishing processes, predominantly, in the form of mechanical polishing. The polishing processes for custom components remain manual and iterative. Determination of the polishing endpoints, i.e., when to stop the process to achieve a desired surface finish, remains a major obstacle to process automation and in the cost-effective custom/3D printing process chains. With the motivation to automate the polishing process of 3D printed materials to a desired level of surface smoothness, we propose a dynamic model of surface morphology evolution of 3D printed materials during a polishing process. The dynamic model can account for both material removal and redistribution during the polishing process. In addition, the model accounts for increased material flow due to heat generated during the polishing process. We also provide an initial random surface model that matches the initial surface statistics. We propose an optimization problem for model parameter estimation based on empirical data using KL-divergence and surface roughness as two metrics of the objective. We validate the proposed model using data from polishing of a 3D printed sample. The procedures developed makes the model applicable to other 3D printed materials and polishing processes. We obtain a network formation model as a representation of the surface evolution from the heights and radii of asperities. We use the network connectivity (Fiedler number) as a metric for surface smoothness that can be used to determine whether a desired level of smoothness is reached or not. [ABSTRACT FROM AUTHOR]

Copper (Cu) doped SnO2 thin films were prepared on glass substrates using sol–gel spin coating by varying post-annealing temperature from 150 to 350 °C. The influence of post-annealing temperature on microstructural, surface morphological, and optical properties of Cu-doped SnO2 thin films have been investigated by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, and Ultraviolet–Visible diffuse reflectance spectroscopy. X-ray diffraction results confirm that Cu-doped SnO2 thin films possess a tetragonal rutile structure. The variation observed in lattice constant values of post-annealed Cu-doped SnO2 thin films is due to the successful substitution of Sn4+ ions by Cu2+ ions in SnO2 crystal lattice, which exhibit a lattice expansion by causing the reduction of dislocation density and micro-strain. The surface morphology of the films shows that grain size increased when the annealing temperature increased. The optical band gap of Cu-doped SnO2 thin films decreased from 3.50 to 3.28 eV with the increase in post-annealing temperature. The spectroscopic ellipsometer is employed to study the extinction coefficient and refractive index of the Cu-doped SnO2 thin films. [ABSTRACT FROM AUTHOR]

Surface morphology is a key factor that determines the quality of laser-based micromachining processes. However, the governing laws of surface morphology in the laser processing process are yet to be clarified, and optimization of processing parameters has to rely on trial and error. Specifically, under multiple-pulse irradiation, it has been difficult to quantify the evolution of the surface morphology because the surface morphology changes with each pulse irradiation, and the ablation process changes accordingly. In this study, we investigated the evolution of surface morphology under femtosecond laser irradiation. Copper and silicon were used as targets, whose surface morphology changes exhibited seemingly opposite behaviors with respect to fluence. Using thousands of datasets, we obtained an evolution equation for surface morphology in terms of surface area, which acts as a good probe of the residual surface energy after ablation. Our model successfully quantifies the cumulative effect of multiple-pulse irradiation on surface morphology changes. [ABSTRACT FROM AUTHOR]

Complex material surfaces can reduce secondary electron emission (SEE) and sputtering via geometric trapping. In this work, the SEE yields for a range of open-cell reticulated carbon foam geometries are characterized using scanning electron microscopy. The total reduction in the SEE yield from carbon foams with a 3% volume fill density and 10–100 pores per inch (PPI) is shown to be between 23.5% and 35.0%. Contributions of a foam backplate are assessed by experimentally and analytically defining the critical parameter, transparency. The transparency of a foam is quantified and is shown to affect the primary electron angular dependence on the SEE yield. For the same thickness of 6 mm, it is found that higher PPI decreases foam transparency from 32% to 0% and reduces the SEE yield. The SEE yield from carbon foams is also shown to have weaker dependence on the morphology of the surface compared with fuzzes and velvets and less variation across individual sample surfaces due to the rigidity of their ligament structures and isotropic geometries. [ABSTRACT FROM AUTHOR]

This article is a literature review of several studies oriented toward the treatment of natural fiber to improve the surface morphology and tensile strength of the fiber. The method used is to review several studies that describe the physical and mechanical properties of natural fiber with different treatments such as immersion of sago fiber in liquid smoke, coconut fiber in NaOH, palm fiber in seawater, and smoking of king pineapple fiber, and banana stem fiber with liquid smoke. The results of the review showed that the treatment was able to increase the tensile strength of sago fiber by 26.77%, coconut fiber by 81.25%, palm fiber by 67.40%, waru bark fiber by 59,97%, coconut fiber with limestone water 34,96 %, king pineapple fiber by 74.45%, and banana stem fiber by 43.78%. The effect of some of these treatments can also change the morphology of the fiber. So, it was concluded that treatment was needed to change the physical properties of the fiber in the form of morphology and mechanical properties in the form of better fiber tensile strength so that the fiber used as a composite reinforcement could improve the mechanical properties of the composite.

The measurement and research on the mechanical properties of coal bodies have important theoretical value for efficient coal mining and disaster prevention. Coal is relatively soft and fragmented, with low strength, making it difficult to prepare standard mechanical test coal samples and impossible to be recycled for repeated testing. There is an urgent need to explore new mechanical testing methods for improving the research on the mechanical properties of coal. Nanoindentation technology can measure the micro mechanical properties of small-scale coal, which has the characteristics of easy sample preparation, fast experiment, and no damage to samples. The physical and micro-mechanical properties of four coals are investigated with the mineral composition testing, morphological scanning and nanoindentation tests. The results show that the minerals of coal samples mainly include amorphous organic matter, clay, quartz and carbonate minerals, and there are significant differences in the mineral compositions of different coals. The 3D morphology of coals indicates that there are huge differences in surface roughness between different coals, and the distribution of minerals in coals exhibits significant heterogeneity. The results of nanoindentation test show that: ① the higher the mass fractions of quartz and carbonate minerals in coal samples, the stronger the surface mechanical properties of samples and the smaller the indentation depth; ② the more complex the components on the surface of samples, the more obvious the heterogeneity of coal, and the higher the degree of dispersion of surface micro mechanical properties distribution; ③ the higher the rank of coal, the higher the degree of metamorphism, and the more developed the external pores, leading to an increase in fracture toughness; ④ fitting the indentation test results reveal a significant linear relationship between elastic modulus and hardness, as well as between elastic modulus and fracture toughness. The linear relationship between elastic modulus and fracture toughness is influenced by peak load.

The synthesis of zeolite nanoparticles is studied comprehensively by adding an organic template as a reflux method, extracted from crystals. The zeolite nano-crystals are quite effectively synthesized by incorporating silica, organic template, and alkali metal. The tetrapropylammoniumhydroxide, tetrapropylammoniumbromide and tetraethyl orthosilicate (TEOS) as organic templates are added for the assistance of zeolite (albite) crystals. A cross-linker TEOS is also mixed. Adding carbon nanotubes and graphene oxide made the morphology of albite more interesting. Nucleation time is an important feature for the formation of albite crystals. The albite nano-shaped crystal is developed for instance when reaction time is less than 240 h, after this period crystal size increases with time. Batch 1 of zeolite is prepared with additives for testing its morphology, like surface area, particle size shape, and crystal geometry. The general trend (e.g., pore volume, percentage composition, particle size, geometry) of zeolite nano-crystal is explained by the help of robust techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller, energy-dispersive X-ray spectroscopy, and scanning electron microscopy.