Surface Characterization Research Articles

Effectiveness of luliconazole vs ketoconazole topical formulation in reversing damaged hair cuticle

Azole antifungal agents are effective agents for treating scalp ailments such as seborrheic dermatitis. Luliconazole (LZ) is a new azole with unique effects against clinically important dermatomycotic fungi. This study examines the impact of different topical formulation of Luliconazole vs Ketoconazole (KZ) on damaged hair cuticle repair after 5 and 10 washes, using SEM images and sensory Analysis.In this in-vitro study,twelve damaged hair tresses were divided into two groups, and treated with LZ and KZ formulations. Both groups underwent pretreatment with 20% Sodium Laureth sulfate (SLES) and damage induction using 9% HO and 20% ammonium solution, followed by respective LZ (Lupizol ZS, manufactured by Lupin Ltd, India) and KZ therapies. SEM imaging and expert sensory analysis were conducted at baseline, after 5, and 10 washes to evaluate surface characterization like cuticle upliftment, smoothness, and softness.After five washes, LZ-treated hair exhibited smooth, intact cuticles with no upliftment, improving to grade 1 cuticle damage. In contrast, KZ-treated hair continued to show substantial upliftment without damage grade improvement. After ten washes, LZ maintained grade 1 damage and 0 µm upliftment, while KZ-treated strands persisted in showing considerable cuticular distress. Sensory analysis supported these results, with LZ improving hair smoothness and softness by 2.42x and 2.72x respectively, after ten washes, significantly outperforming KZ. Visually, LZ-treated hair appeared smoother and healthier, indicating its greater effectiveness in enhancing hair integrity post-washing.The botanical conditioner-based formulation of LZ is more efficacious in enhancing hair integrity post-washing compared to the Ketoconazole formulation. Well-controlled human studies are required to further establish the clinical effects on human participants.

Preparation of surface molecularly‐imprinted magnetic kaolin for selective separation and determination of thiabendazole

AbstractIn this study, a selective sorbent was fabricated by combining a surface molecularly‐imprinted polymer and magnetic kaolin for reliable quantification of thiabendazole (TBZ) coupled with spectrofluorimetry. Several surface characterization methods were conducted to confirm the synthesis of TBZ‐imprinted magnetic kaolin with a polymer thickness of ~48 nm. The molecularly‐imprinted magnetic kaolin (MIP@MKLN) showed high adsorption capacity (8.7 mg/g), remarkable selectivity with an imprinting factor of 3.71 and excellent regeneration ability for up to 10 uses without significant change of its initial adsorption capacity for TBZ. The proposed method had linear range from 5 to 500 μg/mL TBZ concentration with a correlation coefficient of 0.995 and the limit of detection was 1.4 μg/mL. MIP@MKLN was used for selective separation and quantification of TBZ in orange and lemon samples. There were high recovery values ranging from 96.4% to 100.2% with lower relative standard deviations (less than 5%) in the spiked samples under optimized conditions. Overall, the proposed method based on MIP@MKLN as an excellent sorbent could produce a feasible, convenient, and promising method for rapid, selective, and sensitive quantification of TBZ in real samples.

Characterization of Bauhinia Variegata natural fiber treated with bleaching, benzoylation, and alkalization

This study describes the physical, chemical, mechanical as well as morphological characterization of surface modified novel Bauhinia Variegata (BVR) stem fibers. Surface modifications for the fiber are accomplished with bleaching, benzoylation, and alkalization treatments. Using standard test methods, the chemical constituents of BVR fiber are evaluated like α- cellulose 62.5%, hemicellulose 10.8%, lignin18.2% and wax 0.8%. Scanning electron microscopy (SEM) was used to see how different the chemical reactions affect the fiber and SEM images confirmed the enhanced rough surface and existence of voids, along with the subtraction of unusual substances from the fiber surface. In both treated as well as untreated BVR, a Fourier-transform infrared spectroscopy (FTIR) analysis established the presence of cellulose, hemicelluloses, and lignin components. X-ray diffraction test evaluated the crystalline index for treated and raw fiber. The thermogravimetric test provides proof of enhanced thermal sustainability in the BVR upon treating chemically. The increased tensile strength and Young’s modulus upon chemical treatment confirm the improvement in the mechanical properties of the BVR fiber. The moisture absorption test revealed that the hydrophilic nature of BVR was reduced after the chemical treatment, promoting greater fiber-matrix adhesion. Presently studied BVR fiber seems to be a good substitute to the harmful man-made fibers for making of bio composites.

Biofunctionalization of dental abutments by a zinc/chitosan/gelatin coating to optimize fibroblast behavior and antibacterial properties.

Tightly sealed peri-implant gingival tissue provides a barrier against oral bacterial invasion, protecting the alveolar bone and maintaining long-term implant survival. To investigate if zinc can enhance the integration between peri-implant gingival tissue and abutment surface, we herein present novel zinc/chitosan/gelatin (Zn/CS/Gel) coatings prepared using the electrophoretic deposition (EPD) technique. The effect of these coatings on human gingival fibroblasts (hGFs) was investigated by culturing these cells on top of the EPD coatings. Surface characterization demonstrated that Zn2+ were released in a sustained and pH-responsive manner. The preclinical cell culture evaluation of these coatings indicated that the zinc-containing coatings enhanced cell migration, adhesion and collagen secretion of hGFs. Moreover, the zinc-containing coatings exhibited antibacterial efficacy by inhibiting the growth of Porphyromonas gingivalis and reducing attachment of Staphylococcus aureus. Notably, zinc-free CS/Gel coatings prevented attachment of P. gingivalis as well. The coatings were also shown to be cytocompatible with epithelial cells and osteoblasts, which are other relevant cell types which surround dental implants after clinical placement. Based on our findings, it can be concluded that Zn-containing coatings hold promise to enhance the adhesion of gingival tissue to the implant surface, which may potentially contribute to the formation of a robust peri-implant soft sealing counteracting bacterial invasion.

Sulfonation Treatment of Polyether-Ether-Ketone for Dental Implant Uses

There has been a recent uptake in the use of polyether-ether-ketone (PEEK), which is an organic thermoplastic polymer, in the manufacturing of various medical devices, implants, and equipment. Finding the best time and procedure for PEEK after sulfonation is the goal of this research. A total of 30 PEEK discs were sulfonated in this study by immersing them in concentrated (H2SO4) sulfuric acid for various durations and subsequently treated using various post-treatment techniques. Five experiments were carried out, aimed studying the effect of immersion time (5 s–2 min). The methods used as post-treatment were hydrothermal treatment, immersion in NaOH, and washing with acetone. The sulfonation time was measured, and the post-treatment techniques, surface characterizations, were conducted using scanning electron microscopy (SEM) (Electron Optics Instruments, LLC., West Orange, NJ, USA), atomic force microscopy (AFM) (AFM, Vía Burton, CA, USA), and hydrophilic properties. The results were confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The findings of this study demonstrate that sulfonating PEEK caused a structure with a porous network to form in every sample. As the sulfonation time increased, the porous structure became more noticeable and the concentration increased. As a consequence, the roughness of the surface increased notably, and the modified PEEK surface’s wettability improved noticeably. Hydrothermal treatment was determined to be the most successful way for eliminating the leftover sulfuric acid, and sulfonation for 2 min was determined to be ideal. By understanding the best post-treatment procedures and ideal sulfonation duration, a theoretical foundation for the production of sulfonated PEEK for orthopedic uses may be laid.

Development and experimental evaluation of surface enhancement methods for laser powder directed energy deposition microchannels

ABSTRACT This research evaluates Laser Powder Directed Energy Deposition (LP-DED) for producing fine feature internal microchannels. This study is focused on enhancing and characterising the surfaces of microchannels produced using techniques such as abrasive flow machining, chemical milling, chemical mechanical polishing, electrochemical machining, and thermal energy method to modify internal surfaces of microchannels made from NASA HR-1 Fe-Ni-Cr alloy. Flow testing for discharge coefficient measurement is conducted on processed microchannel samples, followed by characterisation through optical microscopy, Scanning Electron Microscopy (SEM), and Computed Tomography. Findings reveal variations in surfaces due to powder adherence, melt pool undulations, and polishing mechanisms. The study emphasises the significance of removing material equivalent to the mean powder diameter to reduce surface roughness and impact the discharge coefficient. The research proposes a ratio for planarising roughness and waviness peak height and density, offering insights for tailored surface adjustments in specific applications requiring reduced flow resistance. Highlights Internal microchannels with thin-walls were fabricated using the laser powder directed energy deposition process. Various surface enhancements and polishing processes were developed to modify the surface texture of the LP-DED channels. Flow testing was conducted to determine the discharge coefficient. Post-test characterisation was completed to obtain cross sectional area, perimeter, surface texture, and general surface condition to analyse results. Ratio of roughness and waviness peak and density (Spk/Spd and Wp/WPc) is proposed as a relevant surface characterisation parameter. Tailored surface modifications for specific end-use applications.

First-principles study of CO2 hydrogenation to methanol on In-Ru alloys: Revealing the influence of surface In/Ru ratio on reaction mechanism and catalyst performance

Designing high-performance catalyst is vital in the field of CO2 methanolization. In this study, two In3Ru surfaces (In3Ru_i and In3Ru_r) were employed as computational models and the density functional theory was applied to study the influence of surface In/Ru ratio on their surface morphologies, reaction mechanisms and catalysis performance for methanol synthesis. Surface characterization reveals that In3Ru_i is higher in surface In/Ru ratio than In3Ru_r, and such difference facilitates CO2 adsorption on In3Ru_r. Being different in surface In/Ru ratio, two surfaces exhibit distinct variations in the reaction mechanism of methanol formation. For In3Ru_i, the “Formate” pathway dominates the first CO2 activation step which leads to methanol production. On the other hand, In3Ru_r prefers the “reverse water-gas shift” pathway (RWGS) in the initial step of CO2 activation, but this mechanism is unable to generate CH3OH due to the kinetic limitation of CO* hydrogenation. Based on the microkinetic modeling, In3Ru_i is superior in both CO2 production rate and CH3OH selectivity than the other one, suggesting higher surface In/Ru ratio benefits methanol formation, which complies well with the experiment. Overall, our study offers a new perspective with respect to how surface morphology of the bimetallic catalyst influences the reaction mechanisms of CO2 hydrogenation.

Evaluation of vateria indicia leaves extract as a green source of potential corrosion inhibitor against mild steel corrosion in 1M HCl solution: electrochemical, and surface characterisation studies

Evaluation of vateria indicia leaves extract as a green source of potential corrosion inhibitor against mild steel corrosion in 1M HCl solution: electrochemical, and surface characterisation studies

Evaluation of plasma parameters’ impact on MRR and surface roughness in plasma polishing of fused silica: An investigation of surface characterization

Advanced fabrication methods with high efficiency are needed to meet the rising demand for precision optical components. This study proposes a plasma-based isotropic polishing method to remove fused silica's surface defects and subsurface damaged layers. Hence, a medium-pressure plasma process is developed to serve this purpose. The qualitative analysis of the plasma and atom emission spectrum explores the plasma generation and scattering of the activated fluorine (F*) radicals inside the plasma chamber. Material removal rate (MRR) and surface roughness variations with different total pressures of 5–30 mbar and substrate dimensions (i.e., varying length between 5 and 45 mm with fixed width and thickness of 5 and 2 mm) at fixed process parameters, i.e., radio-frequency power of 80 W, pressure ratio of 1:1, gas composition of 90:10, have been investigated. The highest and lowest MRR, i.e., 0.039 mm3/min and 0.0061 mm3/min, are achieved at 5 and 30 mbar total pressures on substrates having lengths 45 and 5 mm, respectively. The highest and lowest percentage change in surface roughness observed are 86.4 % and 17.1 % at 5 mbar and 30 mbar for substrates with 5 and 45 mm lengths, respectively. Surface morphology analysis shows the micro-cracks are reduced after plasma processing. The presence of elements, i.e., F and C, through EDX analysis, confirms the reactions on the plasma processed surface. Moreover, The XPS findings demonstrated that minimal radicals could be incorporated onto the fused silica surface during He/O2/SF6 plasma processing. At lower pressure, the surface roughness value increases due to the increased excitation and ionization rate caused by more interaction between the fluorine and surface atoms. The MRR increases with substrate dimension with constant pressure. Larger substrate dimensions result in increased MRR at lower pressure.

Siderite with chelator as high-efficiency Fenton reagent to degrade naphthalene via ferrous liberation and carbon dioxide radical anion-mediated iron redox cycle

Siderite (FeCO3) has been verified to be an effective iron material in Fenton-like process, but large dose of FeCO3 and oxidants limits its application. Here, chelators were successfully used to enhance the degradation of naphthalene (NAP). When 1.0 mM of hydrogen peroxide (H2O2) and 1.0 g L−1 of FeCO3 were applied, in the presence of 0.2 mM oxalic acid (OA), 0.1 mM nitrilotriacetic acid (NTA), or 0.1 mM DL-tartaric acid (DL-TA), 99.3 %, 100 %, or 96.7 % of NAP was degraded within 24 h, respectively. The different roles of chelators were confirmed. For OA and DL-TA, due to weak complexation with iron ions, acid effect and generation of carbon dioxide radical anion (CO2−) contributed to high concentration of Fe2+, while for NTA, chelation and CO2− were two major factors. In addition, the excellent potential application of H2O2/FeCO3/chelator was determined because of (1) lower environmental risk of chemicals; (2) strong tolerance to water matrixes; (3) the excellent stability of FeCO3 confirmed by surface characterizations and cyclic experiment, as NAP was completely degraded after the 6th cycle. At last, H2O2/FeCO3/chelator had superiority over other reduced iron minerals due to lower running cost in lab study, better reusability, and environmental friendliness. Therefore, it is expected that H2O2/FeCO3/chelator technique can provide an effective alternative to Fenton-like process in remediation of NAP contaminated sites.

Exploring chitosan-plant extract bilayer coatings: Advancements in active food packaging via polypropylene modification

UV-ozone activated polypropylene (PP) food films were subjected to a novel bilayer coating process involving primary or quaternary chitosan (CH/QCH) as the first layer and natural extracts from juniper needles (Juniperus oxycedrus; JUN) or blackberry leaves (Rubus fruticosus; BBL) as the second layer. This innovative approach aims to redefine active packaging (AP) development. Through a detailed analysis by surface characterization and bioactivity assessments (i.e., antioxidant and antimicrobial functionalities), we evaluated different coating combinations. Furthermore, we investigated the stability and barrier characteristics inherent in these coatings. The confirmed deposition, coupled with a comprehensive characterization of their composition and morphology, underscored the efficacy of the coatings. Our investigation included wettability assessment via contact angle (CA) measurements, X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), which revealed substantial enhancements in surface concentrations of elements and functional groups of CH, QCH, JUN, and BBL. Scanning electron microscopy (SEM) unveiled the coatings' heterogeneity, while time-of-flight secondary ion mass spectrometry (ToF-SIMS) and CA profiling showed moderately compact bilayers on PP, providing active species on the hydrophilic surface, respectively. The coatings significantly reduced the oxygen permeability. Additionally, single-layer depositions of CH and QCH remained below the overall migration limit (OML). Remarkably, the coatings exhibited robust antioxidative properties due to plant extracts and exceptional antimicrobial activity against S. aureus, attributed to QCH. These findings underscore the pivotal role of film surface properties in governing bioactive characteristics and offer a promising pathway for enhancing food packaging functionality.

Co-Zn Nanoparticles on N-doped Graphene Nanocomposites as Bifunctional Catalysts for Non-enzymatic Electrochemical Sensor and Organic Dye Degradation

Detection of biomolecules by advanced sensing systems and organic pollutant removal is of immense interest in biomedical and environmental remediation sectors. In this regard, effective glucose detection is dynamic in rapid-diagnosis of related diseases and in addition, removal of organic dyes by suitable adsorbent materials is vital for water treatment. The present work involves the facile fabrication of CoZn-N doped graphene nanocomposites and employed in glucose sensors and dye removal. The synthesized materials were characterized to evaluate the structural, morphological, elemental and surface characterizations such as, X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning DR-UV-vis-spectroscopy, electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM) techniques, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. SEM and TEM images revealed the Co-Zn nano particles (NPs) with respective morphologies within the N doped graphene structure. Electrochemical examinations of CoZn-N doped graphene nanocomposites/GCE sensor demonstrated superior sensitivity for the detection of commercial glucose in NaOH. Moreover, CoZnNG nanocatalyst has been investigated for the dye removal of crystal violet (CV), Rhodamine B (RB), methylene blue (MB) and congo red (CR) in the presence of H2O2. CoZnNG catalyst exhibited a maximum efficiency of 96% over CV dye degradation in 30minutes which is comparatively higher than the removal of MB, CR and RB dyes with 36%, 41%, 38% for 120, 60 and 100minutes, respectively. The CoZn-N doped graphene nanocomposites exhibited regeneration, reproducibility, and stability toward dye removal. Such multi-component hybrid N doped graphene could be efficacious for real-time non-enzymatic electrochemical sensor and pollutant removal applications.

Bioinspired core-shell nanofiber drug-delivery system modulates osteogenic and osteoclast activity for bone tissue regeneration

Osteogenic-osteoclast coupling processes play a crucial role in bone regeneration. Recently, strategies that focus on multi-functionalized implant surfaces to enhance the healing of bone defects through the synergistic regulation of osteogenesis and osteoclastogenesis is still a challenging task in the field of bone tissue engineering. The aim of this study was to create a dual-drug release-based core-shell nanofibers with the intent of achieving a time-controlled release to facilitate bone regeneration. We fabricated core-shell P/PCL nanofibers using coaxial electrospinning, where alendronate (ALN) was incorporated into the core layer and hydroxyapatite (HA) into shell. The surface of the nanofiber construct was further modified with mussel-derived polydopamine (PDA) to induce hydrophilicity and enhance cell interactions. Surface characterizations confirmed the successful synthesis of PDA@PHA/PCL-ALN nanofibers endowed with excellent mechanical strength (20.02±0.13 MPa) and hydrophilicity (22.56°), as well as the sustained sequential release of ALN and Ca ions. In vitro experiments demonstrated that PDA-functionalized core-shell PHA/PCL-ALN scaffolds possessed excellent cytocompatibility, enhanced cell adhesion and proliferation, alkaline phosphatase activity and osteogenesis-related genes. In addition to osteogenesis, the engineered scaffolds also significantly reduced osteoclastogenesis, such as tartrate-resistant acid phosphatase activity and osteoclastogenesis-related gene expression. After 12-week of implantation, it was observed that PDA@PHA/PCL-ALN nanofiber scaffolds, in a rat cranial defect model, significantly promoted bone repair and regeneration. Microcomputed tomography, histological examination, and immunohistochemical analysis collectively demonstrated that the PDA-functionalized core-shell PHA/PCL-ALN scaffolds exhibited exceptional osteogenesis-inducing and osteoclastogenesis-inhibiting effects. Finally, it may be concluded from our results that the bio-inspired surface-functionalized multifunctional, biomimetic and controlled release core-shell nanofiber provides a promising strategy to facilitate bone healing.

Experimental evaluation of atmospheric plasma treatment effects on different textures of CFRP composite for aircraft applications

This article examines the impact of Atmospheric Plasma Treatment (APL) on the chemical composition and fracture properties of various textured surfaces (tool and bag side) of carbon fiber/epoxy (CFRP) composites utilized in aircraft applications. For this purpose, parameters of atmospheric plasma (APL) surface treatment were evaluated in comparison to chemical cleaning and peel-ply applications, taking into account its effects on surface properties and adhesive bond strength. A comprehensive variety of surface characterization techniques were utilized to analyze surface modifications, including water and diiodomethane contact angle measurements for assessing surface hydrophilicity, Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR) and X-ray Photoelectron Spectroscopy (XPS) for analyzing chemical composition and functional groups, and Profilometry, Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) for evaluating surface topography and morphology. Experimental results indicated that the reduction in the contact angle following plasma treatment correlated with the elevated oxygen concentration and the presence of polar functional groups (e.g. -OH, -NH2, -NH3, C=O, O-C=O) on the composite surface. Plasma treatment, especially at low nozzle speeds, increased surface roughness on the bag side surfaces. This prevented adhesive penetration and led to gas entrapment, resulting in adhesive failure mode and reduced single lap shear strength for the bag side. In contrast, on the tool side surfaces, the plasma treatment led to a remarkable 19.7% enhancement in shear strength, highlighting its effectiveness.

Amorphous solid dispersion of a binary formulation with felodipine and HPMC for 3D printed floating tablets

This study focuses on the combination of three-dimensional printing (3DP) and amorphous solid dispersion (ASD) technologies for the manufacturing of gastroretentive floating tablets. Employing hot melt extrusion (HME) and fused deposition modeling (FDM), the study investigates the development of drug-loaded filaments and 3D printed (3DP) tablets containing felodipine as model drug and hydroxypropyl methylcellulose (HPMC) as the polymeric carrier. Prior to fabrication, solubility parameter estimation and molecular dynamics simulations were applied to predict drug-polymer interactions, which are crucial for ASD formation. Physical bulk and surface characterization complemented the quality control of both drug-loaded filaments and 3DP tablets. The analysis confirmed a successful amorphous dispersion of felodipine within the polymeric matrix. Furthermore, the low infill percentage and enclosed design of the 3DP tablet allowed for obtaining low-density systems. This structure resulted in buoyancy during the entire drug release process until a complete dissolution of the 3DP tablets (more than 8 h) was attained. The particular design made it possible for a single polymer to achieve a zero-order controlled release of the drug, which is considered the ideal kinetics for a gastroretentive system. Accordingly, this study can be seen as an advancement in ASD formulation for 3DP technology within pharmaceutics.

Facile synthesis and surface characterization of platinum and gold bimetallic nanoparticles prepared using hydroalcoholic extract of Bryophyllum Pinnatum: Enhancing efficacy against breast cancer

Primary aim of the proposed study was to explore the green technique for synthesis of bimetallic nanoparticles of platinum and gold metal by employing Bryophyllum pinnatum hydroalcoholic extract (BrPi-P-G-NPs) to explore their potential medicinal properties. Green synthesised bimetallic nanoparticles were characterized by techniques including UV spectroscopy, XRD, FTIR, SEM, TEM, DSC, Particle size and Zeta Potential analysis. Experimental findings confirmed that BrPi-P-G-NPs demonstrate irregular shape, with an average size 34.5 nm. Zeta potential for BrPi and BrPi-P-G-NPs were found to be −8.1 and −24.1 mV, respectively. At a concentration of 75 µg mL−1, the MTT and trypan blue assays of the BrPi-P-G-NPs revealed a cell inhibition rate of 63.54 % and 60.23 %, respectively. In the MCF-7 cell line, the MTT and trypan blue assays recorded IC50 values of 153.54 and 158.04, respectively, for the BrPi-P-G-NPs at the same concentration. Thus, biologically synthesized BrPi-P-G-NPs demonstrated promising anti-cancer properties against human breast cancer cell lines, while showed no signs of toxicity. The enhanced biological activity of BrPi-P-G-NPs can be attributed to their distinctive properties at the nanoscale, as both exhibit lower polydispersity and nanoparticle size, which contribute to increased reactivity and interactions with biological systems. As a result, these BrPi-P-G-NPs nanoparticles synthesized through the biogenic approach using plant extract of Bryophyllum pinnatum have immense potential for a wide range of pharmaceutical applications.

Study on temperature and hardness behaviors of Al-6060 alloy during magnetic abrasive finishing process using artificial neural networks

Magnetic Abrasive Finishing (MAF) revolutionizes surface finishing by utilizing magnetic fields to apply pressure, ensuring exceptionally high-quality surfaces. Its potential for ultra-precise finishing with fine magnetic abrasives is particularly noteworthy. This study analyzes subsurface temperature dynamics during the MAF process on Al-6060, recognizing temperature's pivotal role in shaping surface texture and mechanical-chemical properties. Unbonded magnetic abrasives containing SiC were used without lubrication or coolants in experimentation. Experimental parameters, including machining gap, abrasive weight, voltage, and rotational speed, were systematically varied using a Box-Behnken Design of Experiments. An artificial neural network facilitated comprehensive data modeling, enabling a detailed parametric study. Post-processing surface characterization provided crucial insights into the impact of surface temperature rise on surface finish and hardness. This holistic approach enhances understanding of temperature's influence on MAF efficacy and its outcomes on Al-6060 surfaces. Experimental findings demonstrate MAF's effectiveness in achieving low-temperature finishing of Al-6060, with a maximum surface temperature of 36ºC. ANOVA analysis quantitatively determined that voltage has greatest influence (55.56%), followed by abrasive weight (20.00%) and machining gap (13.89%), with rotational speed having the least impact (2.22%). Qualitatively, the developed ANN model accurately predicted changes in surface roughness (ΔRa), temperature (ΔT), and hardness (ΔH), with maximum errors of 4.107%, 5.588%, and 6.680%, respectively. XRD analysis provided quantitative evidence of SiC diffusion into the surface, resulting in a hardness increase from 2.7 HV to 5.6 HV. Additionally, chemical substrates deposition, such as silicon carbide, kaolinite, iron silicide, and cristobalite, elucidated chemical-mechanical interactions during the process at such low temperatures.

Effects of washing agents on the mechanical and biocompatibility properties of water-washable 3D printing crown and bridge resin

Three-dimensional (3D) printing, otherwise known as additive manufacturing in a non-technical context, is becoming increasingly popular in the field of dentistry. As an essential step in the 3D printing process, postwashing with organic solvents can damage the printed resin polymer and possibly pose a risk to human health. The development of water-washable dental resins means that water can be used as a washing agent. However, the effects of washing agents and washing times on the mechanical and biocompatibility properties of water-washable resins remain unclear. This study investigated the impact of different washing agents (water, detergent, and alcohol) and washing time points (5, 10, 20, and 30 min) on the flexural strength, Vickers hardness, surface characterization, degree of conversion, biocompatibility, and monomer elution of 3D printed samples. Using water for long-term washing better preserved the mechanical properties, caused a smooth surface, and improved the degree of conversion, with 20 min of washing with water achieving the same biological performance as organic solvents. Water is an applicable agent option for washing the 3D printing water-washable temporary crown and bridge resin in the postwashing process. This advancement facilitates the development of other water-washable intraoral resins and the optimization of clinical standard washing guidelines.

Applying Gaussian Mixture Models for Enhanced Characterization of Featured Surfaces and Mixed Lubrication Analysis

Abstract Understanding surface topography is vital for optimizing the performance of engineering components. Featured surfaces, with distinct patterns and textures, have garnered attention for their potential to reduce friction and wear. However, accurately describing their topography poses challenges, necessitating effective segmentation methods in many applications. This paper proposes utilizing the Gaussian Mixture Models (GMMs) clustering method as a novel approach for surface metrology analysis of featured surfaces. The GMMs provide an approach to identify and analyze specific surface features and enhance comprehension of their contributions to functionality. The paper presents a comprehensive methodology involving surface characterization, GMMs clustering, plateau reference plane location, and calculation of essential topography parameters. Results from four different surfaces are discussed, demonstrating the effectiveness of the proposed GMMs-based methodology in segmenting plateau regions, grooves, and porosity.

Assessing Satellite Data’s Role in Substituting Ground Measurements for Urban Surfaces Characterization: A Step towards UHI Mitigation

Urban surfaces play a crucial role in shaping the Urban Heat Island (UHI) effect by absorbing and retaining significant solar radiation. This paper explores the potential of high-resolution satellite imagery as an alternative method for characterizing urban surfaces to support UHI mitigation strategies in urban redevelopment plans. We utilized Landsat images spanning the past 40 years to analyze trends in Land Surface Temperature (LST). Additionally, WorldView-3 (WV3) imagery was acquired for surface characterization, and the results were compared with ground truth measurements using the ASD FieldSpec 4 spectroradiometer. Our findings revealed a strong correlation between satellite-derived surface reflectance and ground truth measurements across various urban surfaces, with Root Mean Square Error (RMSE) values ranging from 0.01 to 0.14. Optimal characterization was observed for surfaces such as bituminous membranes and parking with cobblestones (RMSE < 0.03), although higher RMSE values were noted for tiled roofs, likely due to aging effects. Regarding surface albedo, the differences between satellite-derived data and ground measurements consistently remained below 12% for all surfaces, with the lowest values observed in high heat-absorbing surfaces like bituminous membranes. Despite challenges on certain surfaces, our study highlights the reliability of satellite-derived data for urban surface characterization, thus providing valuable support for UHI mitigation efforts.