Minor Surface Research Articles

Interfacial Interaction between Zn2+ and Surface Functional Groups Impacting Self-Assembly of ZnO on Cellulose Nanofibrils.

The mechanism underlying the interfacial interaction between ZnO and surface functional groups, which drives the self-assembly of ZnO nanoflowers on the cellulose nanofibril (CNF) surface, remains inadequately understood. Moreover, the ideal sites for the loading and growth of ZnO nanoflowers on the oxygen atoms (Os) of various surface functional groups on the CNF surface are not well-defined. This work addressed these gaps by systematically regulating the size and surface charge density of CNF templates through minor surface modifications and adjustments in processing cycles by using an ultrafine grinder. Physicochemical analyses demonstrated that the ZnO nanoflowers exhibited sizes (μm)/pieces/thickness (nm) of 0.86/16/20.1 for ZnO/TOCNFs, 0.88/17/20.4 for ZnO/ACNFs, and 0.89/16/20.5 for ZnO/ECNFs, respectively. Simulation calculations revealed that the interaction between Zn2+ ions and the Os of hydroxyl (-OH) groups exhibited the most favorable binding energy of -31.7 kcal/mol. These findings suggested that the surface charge density rather than specific surface functional groups primarily governs the loading and growth of ZnO nanoflowers on the CNF surface. The OS from -OH groups on the surface of CNF templates were optimal for both the loading and growth of ZnO nanoflowers. Overall, this study provides crucial theoretical insights into the design and optimization of the ZnO/CNF composites.

Three-year clinical performance of direct restorations using low-shrinkage Giomer vs. nano-hybrid resin composite

ObjectivesThe objective of this investigation was to compare the clinical performance of a nano-hybrid resin composite and a low-shrinkage Giomer resin composite.Material and methodsIn total, 35 pairs of restorations were performed using either low-shrinkage Giomer (Beautifil II LS, Shofu Inc.) or nano-hybrid (Clearfil Majesty Posterior) resin composite in 35 patients by two operators using the relevant adhesives, i.e., FL-Bond II (Shofu Inc.) and Clearfil SE Bond (Kuraray), with the self-etching technique according to each manufacturer's instructions. Two clinicians assessed the restorations 2 weeks (baseline); 6 months; and 1, 2, and 3 years after the restorative procedures using FDI (World Dental Federation) criteria (Scores 1–5). Data were analyzed using the marginal homogeneity and McNemar tests. The survival rate was calculated using Kaplan–Meier survival analysis and the survival of the two groups was compared with the log-rank test (p = 0.05).ResultsThe mean observation period was 37.7 ± 6.8 months. All restorations completed their 3-year follow-up. The criteria were mainly rated with high (1 or 2) scores for quality in both groups. Only one restoration in the low-shrinkage Giomer resin composite group was accepted as a failure at the 2-year recall due to retention loss.ConclusionAt the 3-year follow-up, the performance of the restorations using the Giomer and the nano-hybrid resin composite were similar and clinically acceptable.Clinical relevanceThe low-shrinkage Giomer resin composite exhibited a similar clinical performance to the nano-hybrid resin composite after 3 years in service with both materials displaying minor surface deteriorations at the 3-year recall.Clinical Trial Registrationhttps://clinicaltrials.gov, identifier: NCT02823769.

CTDD-YOLO: A Lightweight Detection Algorithm for Tiny Defects on Tile Surfaces

To address the challenge of detecting tiny flaws in tile defect detection, a lightweight algorithm for identifying minor defects in tile images has been developed, referred to as CTDD-YOLO. Firstly, CAACSPELAN is proposed as the core component of the backbone network for extracting features of tile defects; secondly, full-dimensional dynamic convolution ODConv is introduced at the end of the backbone network to enhance the model’s ability to deal with tiny defects; next, a new neck network, CGRFPN, is proposed to improve the model’s ability to represent multi-scale features and enhance the model’s ability to recognize small targets in the context of large formats; finally, MPNWD is proposed to optimize the loss function to improve the model’s detection accuracy further. Experiments on the Ali Tianchi tile defect detection dataset show that the CTDD-YOLO model not only has a lower number of parameters than the original YOLOv8n but also improves the mAP by 7.2 percentage points, i.e., the proposed model can more accurately recognize and deal with minor surface defects of tiles and can significantly improve the detection effect while maintaining the light weight.

Synthesis and performance evaluation of bio-derived and synthetic carbon as lithium-sulfur battery cathode

The next-generation of batteries need be both energy dense and environment friendly. Lithium sulfur batteries (LSBs) satisfy both criteria but their practical implementation is marred by the highly resistive nature of sulfur. Carbon-based cathodes play a vital role in mitigating the issue because their high conductivity allows for effective electron transfer during electrochemical cycling. Synthesis and electrochemical evaluation of carbon-based cathodes from two different sources for LSBs was carried out. Herein, two kinds of carbon, namely bio-derived carbon from coconut shells (CC500) and N-doped carbon (NC) from polyacrylonitrile fibers were synthesized and sulfur was incorporated via the melt diffusion route. The composites are characterized by PXRD and TGA, which determined 80 wt% mass loading of sulfur. The higher intensity of G-band over D-band in Raman spectroscopy indicates greater graphitic character for CC500 compared to NC. SEM images show large macro-pore like tunnels in CC500 while NC appears are irregular chunks. EDAX spectra showed 20 wt% N content in NC while CC500 is largely carbon with some minor surface oxygen. In galvanostatic charge–discharge cycling of coin cells, bare CC500/S shows better specific capacity compared to NC/S samples but the trend flips once a separator modified with 4 mg of graphene oxide (GO) is introduced (indicated as NC/S/GO4 and CC500/S/GO4). This points towards synergy between N-doped carbon and GO layer in retaining the soluble polysulfides in the catholyte region. NC/S/GO4 exhibited better capacity i.e., 1453, 1024, 866, 787, 697 mAh/g versus 1016, 779, 672, 551, 441 mAh/g offered by CC500/S/GO4 when discharged at 50, 100, 200, 300 and 500 mA/g, respectively.

Fracture properties of carbon/glass fiber composite laminates with surface scratch damage

Carbon/glass fiber reinforced polymer composite panels may experience minor surface scratches during processing or use. These shallow scratches can expand and potentially lead to dangerous fracture failure as the specimens are continually loaded. This study presents a closed form non-LEFM model for predicting the fracture performance of materials with slight scratches. First, 3-p-b tests and direct tensile tests were conducted on 115 carbon/glass fiber composite laminated panel specimens. A comparison of the two test methods revealed that 3-p-b tests were more suitable for analyzing quasi-brittle fracture in carbon/glass fiber composites. The tensile strength ft and fracture toughness KIC of 3-p-b specimens with and without notched were discussed using the weighted average calculation method to determine the thickness of the “composite” single-layer prepreg as the characteristic composite unit Cch. A normal distribution method was also introduced to analyze the experimental discrete points, covering almost all the experimental scatterers with desired reliability. Furthermore, the same method was applied to specimens with different layup methods, and the data analysis confirmed its effectiveness. As the seam-thickness ratio α increases within a certain range, the tensile strength ft showed an overall increasing trend and the peak load Pmax showed a decreasing trend. Additionally, the laboratory routine dimensions can be utilized to efficiently predict the fracture of large size members with defects at the same thickness, which is significant for the safe design of composite structures.

Synthesis of Amphiphilic Polyacrylates as Peelable Coatings for Optical Surface Cleaning

Optical instruments require extremely high precision, and even minor surface contamination can severely impact their performance. Peelable coatings offer an effective and non-damaging method for removing contaminants from optical surfaces. In this study, an amphiphilic polyacrylate copolymer (PMLEA) was synthesized via solution radical copolymerization using the lipophilic monomer lauryl acrylate (LA) and hydrophilic monomers ER-10, methyl methacrylate (MMA), and butyl acrylate (BA). The structure and molecular weight of the copolymer were characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC). The hydrophilic–lipophilic balance, surface tension, and wettability of the copolymer were analyzed through water titration, the platinum plate method, and liquid contact angle tests. The cleaning performance of the copolymer coating on quartz glass surface contaminants was evaluated using optical microscopy and Ultraviolet-Visible Near-Infrared (UV-Vis-NIR) spectroscopy. The study examined the effect of varying the ratio of LA to ER-10 on the hydrophilicity, lipophilicity, cleaning efficiency, and mechanical properties of the copolymer coating. The results showed that when the mass ratio of LA to ER-10 was 1:2, the synthesized copolymer exhibited optimal performance in removing dust, grease, and fingerprints from quartz glass surfaces. The coating had a tensile strength of 2.57 MPa, an elongation at break of 183%, and a peeling force of 2.07 N m−1.

Effect of Ti, Mn and Mo on the microstructure and properties of CoCrFeNi high entropy alloy coatings prepared by laser cladding

CoCrFeNi-based High Entropy Alloys (HEAs) coatings, with additions of Ti, Mn, and Mo, were synthesized using laser cladding (LC). The pure CoCrFeNi HEA had a uniform FCC structure, exhibiting the lowest hardness and wear resistance but good corrosion resistance. The Ti-added HEA had an FCC+Laves+η phase structure, showing increased hardness and wear resistance due to abrasive and mild surface fatigue wear, though with the poorest corrosion resistance. The Mn-added HEA maintained a single FCC structure with coarser grain boundaries, exhibiting lower hardness and reduced wear resistance due to adhesive, abrasive wear, and minor surface fatigue wear, but with the best corrosion resistance.The Mo-added HEA developed a eutectic structure of FCC and σ phases, achieving the highest hardness and wear resistance due to oxidative wear, but showed moderately decreased corrosion resistance. The varying microstructures significantly impacted the coatings' mechanical properties and corrosion behavior, highlighting the critical role of alloying elements in customizing LCed-HEA coatings for specific applications.

Evaluation of Enamel Surface Properties Submitted to Bleaching With 35% Hydrogen Peroxide Associated With Titanium Tetrafluoride (TiF4).

This study evaluated the color change, surface roughness, mineral content and morphology of enamel bleached with 35% hydrogen peroxide (HP) combined with an experimental gel containing 1% titanium tetrafluoride (TiF4). Bovine enamel blocks were treated with (n = 12): (TiF) experimental gel containing 1% TiF4, (HP) 35% HP, (HPT) 35% HP + 1% TiF4and (CT) control. Bleaching with HP was performed in 3 sessions (3 × 15 min/applications). pH, colorimetric parameters, surface roughness, mineral content and enamel morphology were determined. The pH was evaluated for 45 min. The color parameters were determined before bleaching (T0), and 14 days elapsed from the last bleaching session (T4). Surface roughness was analyzed at T0 and immediately after last bleaching session (T3). Enamel mineral content and morphology were verified at T4. Data were statistically analyzed by one-way, two-way ANOVA and Kruskal-Wallis (α = 0.05). TiF increased surface roughness, and no differences between HP and HPT in terms of color and - mineral content. Ti was detected only on TiF, and slight surface morphology changes were observed in bleached enamel. The combination of TiF4 and 35% HP did not interfere with the enamel bleaching effect, controlled surface roughness, and kept mineral content but promoted a minor surface morphology alteration. Due to the adverse effects of bleaching, titanium tetrafluoride (TiF4) has gained attention for its therapeutic properties, including the ability to reverse mineral loss and neutralize remineralization of mineral structures. Therefore, TiF4's remineralizing capacitymay be a good alternative for incorporation into hydrogen peroxide bleaching agents.

Significant improvement of n-contact performance and wall plug efficiency of AlGaN-based deep ultraviolet light-emitting diodes by atomic layer etching.

The reactive ion etching (RIE) process is needed to fabricate deep ultraviolet (DUV) light-emitting diodes (LEDs). However, the n-contact performance deteriorates when the high-Al n-AlGaN surface undergoes RIE, leading to decreased LED performance. In this study, we employed an atomic layer etching (ALE) technology to eliminate surface damage generated during the mesa etching process, thus enhancing the n-Al0.65Ga0.35N ohmic contact. The improved contact performance reduced LED operation voltage and mitigated device heat generation. It was observed that DUV LEDs treated with 200 cycles of ALE showed a reduction in operating voltage from 8.3 to 5.2 V at 10 mA, with a knee voltage of 4.95 V. The peak wall plug efficiency (WPE) was approximately 1.74 times that of reference devices. The x-ray photoelectron spectroscopy (XPS) analysis revealed that ALE removed the surface damage layer induced by plasma etching, eliminating surface nitrogen vacancies and increasing surface electron concentration. Consequently, it facilitated better ohmic contact formation on n-Al0.65Ga0.35N. This study demonstrates that the ALE technology achieves etching with minor surface damage and is suitable for use in III-nitride materials and devices to remove surface defects and contaminations, leading to improved device performance.

Evaluation of the Loss of Surface Roughness Following the Use of Four Different Instruments for Mechanical Debridement of Dental Implants: An In-vitro Pilot Study

To compare the dental implant surface properties such as mean surface roughness, roughness depth, and the surface loss produced by different prophylactic instrument types. Twenty-four surfaces of twelve dental implants were treated using titanium curettes, titanium-coated curettes, an air abrasion unit, and titanium brushes. The dental implants were inserted partially into a Styrofoam base, exposing one-third to simulate cases of peri-implantitis. The exposed surface was coated with artificial dental calculus (ADC) and divided into four groups for treatment. The arithmetic mean surface roughness (Ra) and the mean roughness depth (Rz) were assessed using the confocal microscope, and the surface loss (SL) area was calculated from the scanning electron microscopic images using an image analysis software. The Ra value varied between 1.08 to 0.29 µm, the Rz value between 10.3 to 70.5 µm, and the mean surface loss area between 154 to 9410 µm2. The One-way ANOVA analysis showed a statistically significant difference between the four groups (P < 0.05). The air abrasion unit showed the highest mean roughness value of 1.08 ± 0.14 µm, mean roughness depth of 70.5 ± 2.21 µm, and a minor surface area loss of 154 ± 132 µm2. In comparison, the titanium brushes showed the least Ra and Rz of 0.29 ± 0.05 µm and 10.3 ± 2.32 µm, respectively, whereas the titanium-coated curettes showed the highest loss of surface area 9410 ± 91.6 µm2. The air abrasion unit was shown to have the least detrimental effect on the implant surface when removing the artificial dental calculus compared to the other three methods.

Physico-mechanical, structural, and mineralogical analysis of composite concrete incorporating hydraulic lime and pozzolan

This study investigates alternatives to Portland cement (PC) through the utilization of pozzolanic materials like natural hydraulic lime and pozzolan in mortar and concrete production, offering both environmental and economic advantages. Natural hydraulic lime is particularly esteemed for its relevance in restoring architectural relics and preserving cultural heritage, while the incorporation of pozzolan and fine and coarse aggregates adds value to local resources. The study employs a range of comprehensive characterization techniques, including physico-chemical, mineralogical, and mechanical analyses such as X-ray fluorescence, particle size assessment, bulk density evaluation, shrinkage testing, water absorption analysis, X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and Proctor Normal and compressive strength tests, among others. Five different formulations, varying from 20 % to 40 % hydraulic lime content and a fixed 25.00 % pozzolan content, underwent testing across five curing periods (7, 14, 28, and 90 days). The results underscore the significant influence of curing time and hydraulic lime proportion on the physical, mineralogical, and mechanical characteristics of lime concrete. Scanning electron microscopy reveals a well-structured matrix in samples from various formulations, credited to effective void filling by lime and pozzolan. Furthermore, the identification of C-S-H phases through X-ray diffraction analysis enhances the concrete matrix, leading to a notable increase in compressive strength of up to 22.00 MPa. Water absorption rises with curing time due to the air curing process, fostering the formation of minor surface pores. This research assesses the environmental impact of hydraulic lime concrete across its lifecycle, underscoring the potential of pozzolans and natural hydraulic lime to produce locally-sourced, economical, and environmentally friendly construction materials, thereby contributing to global efforts in reducing carbon emissions.

Long range transport of South and East Asian anthropogenic aerosols counteracting Arctic warming

The large-scale convection during the Asian summer monsoon plays an important role in the rapid transport of boundary layer aerosols into the Asian summer monsoon anticyclone. Here, using the state-of-the-art ECHAM6–HAMMOZ aerosol-chemistry-climate model, we show that these aerosols are further transported to the Arctic along isentropic surfaces by the Brewer-Dobson-Circulation (BDC) during the monsoon season. Our model simulations show that East and South Asian anthropogenic emissions contribute significantly to the aerosol transported to the Arctic, which causes a higher negative net aerosol radiative forcing at the surface (dimming) of −0.09 ± 0.02 Wm−2 and −0.07 ± 0.02 Wm−2, respectively. Over the Arctic, the East Asian anthropogenic aerosols that include large amounts of sulfate cause a seasonal mean net radiative forcing at the top of the atmosphere (TOA) of −0.003 ± 0.001Wm−2 and a surface cooling of −0.56 K while the black carbon dominated aerosol from South Asia shows a positive TOA forcing of +0.004 ± 0.001Wm−2 with an only minor surface cooling of −0.043 K. Overall, the long-range transport of South Asian aerosols results in a notably warming throughout the atmospheric column but minimal temperature response at the Arctic surface. Conversely, East Asian aerosols cool the troposphere and heat the lower stratosphere in the Arctic. The Asian aerosol thus plays an ambivalent role, with the East Asian sources in particular having the potential to counteract the rapid rise in Arctic temperatures and the associated melting of snow and ice.

Deformation behaviors of defective aluminum honeycomb sandwich panels subjected to in-panel compressive loading: An experimental study with mirror-assisted multi-view DIC

Honeycomb sandwich panels have been extensively utilized in the aerospace and automotive industries for their prominent advantages of energy absorption, high strength and tailorable anisotropic mechanical properties. Nevertheless, the common presence of local core-to-skin disbonding poses an urgent need to understand the mechanical behaviors of defective honeycomb sandwich panels. The present work investigates the deformation behaviors and evolutions of aluminum honeycomb sandwich panels with varying sizes of circular artificial core-to-skin disbonding defects using mirror-assisted multi-view digital image correlation (MV-DIC). Based on the 3D profiles and dual-surface deformation fields obtained with mirror-assisted MV-DIC, it is revealed that disbonding defects induced local surface undulations with severe local strain concentrations and determined the mode of gradual bending and buckling. Defects with a diameter below 20 mm induced minor local surface undulations and slight decreases in buckling load. When the diameters of defects reach 30 mm, extensive surface convex deformation occurs and the buckling load decreases by 23 %. The results validate mirror-assisted MV-DIC as a cost-effective and practical technique for characterizing dual-surface 3D deformation of sheet composite materials and structures.

Rapid cellular uptake of citrate-coated iron oxide nanoparticles unaffected by cell-surface glycosaminoglycans.

Citrate-coated iron oxide nanoparticles, specifically Synomag®-COOH (SynC), are promising tracers in magnetic particle imaging (MPI) due to their high magnetic moments and rapid cellular uptake. The mechanisms driving efficient SynC uptake remain unclear. Previous observations suggest a role of the extracellular glycocalyx during nanoparticle uptake. Here, we ascertain whether the cell-surface glycosaminoglycans (GAGs) regulate the uptake of SynC. Using transmission electron microscopy (TEM), we visualized SynC uptake by THP-1 cells, a human acute monocytic leukemia cell line. We investigated the interaction of SynC with GAGs in living cells using click-chemistry-based labeling. Upon treating THP-1 cells with chondroitinase or hyaluronidase and with a xylosyltransferase-deficient cell line, we quantified SynC uptake and measured interactions of SynC with cells in real time using magnetic particle spectroscopy (MPS). The THP-1 cell membrane engulfed or formed extensions around SynC, indicating uptake through pinocytosis and phagocytosis. We measured an increased MPS signal of SynC within seconds of cell contact, suggesting an interaction with extracellular components like the glycocalyx. Upon adding SynC to THP-1 cells, we could not observe disruption of fluorescently labeled GAGs or an enhanced intracellular fluorescence, implying that SynC does not accelerate the turnover of GAGs by binding. Lack of chondroitin sulfate, heparan sulfate, and hyaluronic acid did not affect the rapid magnetic behavior increase of SynC upon cell contact. Accordingly, we measured no significant differences in SynC uptake between wild type cells and our GAG-deficient models. These findings suggest that GAGs act as a permeable bandpass for SynC nanoparticles with a minor negative surface charge of -13.8 mV. This finding has significant implications for MPI-based cell tracking because it facilitates efficient tracking of cell types that lack a strong repulsion by cell-surface GAGs. It will be crucial to investigate whether the rapid uptake of SynC is cell-type specific and influenced by different extracellular matrix compositions.

Milling or grinding for manufacturing of an Alloy 718 gas turbine component? – A comparison of surface integrity and productivity

Milling is traditionally the most used machining method when manufacturing complex gas turbine components. In particular those made from nickel-based superalloys. However, for larger free form surfaces, grinding may be an efficient alternative that could be used throughout the complete manufacturing route, from roughing to finishing. Hence, in this work the two processing methods has been compared in regard to surface integrity and productivity.Machining tests have been performed on case plates of heat-treated Alloy 718 using best practise setting for roughing and finishing with grinding and milling. The surface integrity of the work pieces was evaluated regarding surface topography, residual stresses, and deformation. This comparison showed that the main advantage with grinding is the ability to switch between roughing and finishing by just altering the depth of cut. Further, grinding offers lower surface roughness, compressive residual stresses, and significantly lower degree of deformation.From a productivity perspective, deep grinding may offer high material removal rates and ability to machine several work pieces in the same setup. However, grinding is limited to simpler free form geometries and may result in minor surface damages and abrasive surface residue. For selection of machining strategy, advantages and drawbacks shown in this work need to be considered for the application at hand in respect to productivity, surface integrity and requirements on fatigue life.

The influence of the cutting tool geometry on the surface quality of the parts manufactured by WAAM - Wire Arc Additive Manufacturing

Thin-walled components have extensive usage in the aviation, aerospace, automotive, and energy sectors. Wire Arc Additive Manufacturing (WAAM) additive technology is a technology that is used to produce thin-walled components by adding layers by layers. MIG/MAG welding technology is used in WAAM. The milling of thin-walled components often results in chatter, which causes waves on the milled surfaces. The variable helix angle reduces chatter during milling. The study found that a constant helix angle of 30°-30°-30° caused the active part of the wall to deflect towards the cutting tool, resulting in the least desirable outcomes. In contrast, cutting tools with 30°-30°-25° and 30°-30°-35° helix angles produced comparable results with minor surface waves.

Optimisation of free-abrasive assisted lapping process with vitrified bonded diamond plates for sapphire substrates

To improve the processing performance of vitrified bonded diamond fixed-abrasive lapping plates for processing sapphire substrates, a free-abrasive was added to the lapping slurry to enhance the self-dressing ability of the lapping plate to achieve efficient and high-quality processing of sapphire substrates. The processing effectiveness and mechanism of a free-abrasive assisted fixed-abrasive lapping plates (FAAFALP) lapping process for sapphire substrates were analysed and revealed via a single-factor experiment. To optimise the lapping process of the FAAFALP of sapphire substrates with good overall performance (high material removal rate (MRR), minor surface roughness (Ra) and big lapping plate wear ratio (η)), the effects and the optimal parameters combination of the lapping pressure, lapping speed and free-abrasive concentration on MRR, Ra and η of lapping-processed sapphire substrates were investigated using orthogonal experiments. Furthermore, the experimental results were combined with process parameters to establish a regression model. The multi-evaluation index optimisation problem was transformed into a single-index optimisation problem via the grey relational analysis (GRA) to evaluate each parameter's performance comprehensively. The results revealed that an MRR increased by 22.2 % to 2.48 μm/min, the smallest surface roughness Ra of 0.141 μm, and the lapping plate wear ratio η relatively increased to 14.88 was obtained when a free-abrasive of SiO2 with a particle size of 14 μm was added into lapping slurry. Compared with no free-abrasive lapping process, free-abrasive can significantly improve the lapping plate's self-dressing ability and enhance the sapphire substrates' processing effect. The lapping speed, lapping pressure and free-abrasive concentration had different influence degrees on MRR, Ra and η. The established regression equations predicted the response values of MRR, Ra and η to be 99.87 %, 99.06 % and 98.59 %, respectively, and the relative errors between the predicted and actual measured values were <12 %. With increased lapping speed, MRR initially decreased but subsequently increased, and Ra and η gradually decreased. MRR and η continuously increased with increased lapping pressure, whereas Ra decreased. With increased free-abrasive concentration, MRR, Ra and η initially increased but subsequently decreased. Comparing the optimised results obtained by intuitive analysis, the parameters optimised via the GRA were used to obtain sapphire substrates lapping with an MRR of 3.81 μm/min, Ra of 0.133 μm and η of 20.4, and the overall lapping performance was better 42.92 %, 102.90 % and 43.60 % than that of intuitive analysis for MRR, Ra and η. Therefore, combining orthogonal experiments and GRA can provide new ideas for optimising the FAAFALP lapping process for sapphire substrates.

Altered cortical and subcortical morphometric features and asymmetries in the subjective cognitive decline and mild cognitive impairment.

This study aimed to evaluate morphological changes in cortical and subcortical regions and their asymmetrical differences in individuals with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). These morphological changes may provide valuable insights into the early diagnosis and treatment of Alzheimer's disease (AD). We conducted structural MRI scans on a cohort comprising 62 SCD patients, 97 MCI patients, and 70 age-, sex-, and years of education-matched healthy controls (HC). Using Freesurfer, we quantified surface area, thickness, the local gyrification index (LGI) of cortical regions, and the volume of subcortical nuclei. Asymmetry measures were also calculated. Additionally, we explored the correlation between morphological changes and clinical variables related to cognitive decline. Compared to HC, patients with MCI exhibited predominantly left-sided surface morphological changes in various brain regions, including the transverse temporal gyrus, superior temporal gyrus, insula, and pars opercularis. SCD patients showed relatively minor surface morphological changes, primarily in the insula and pars triangularis. Furthermore, MCI patients demonstrated reduced volumes in the anterior-superior region of the right hypothalamus, the fimbria of the bilateral hippocampus, and the anterior region of the left thalamus. These observed morphological changes were significantly associated with clinical ratings of cognitive decline. The findings of this study suggest that cortical and subcortical morphometric changes may contribute to cognitive impairment in MCI, while compensatory mechanisms may be at play in SCD to preserve cognitive function. These insights have the potential to aid in the early diagnosis and treatment of AD.

Examining the microstructure, morphological features, and wetting characteristics of Ti/TiN/TiAlN thin films produced through RF/DC magnetron co-sputtering

This study reports synthesizing and characterizing Ti/TiN/TiAlN thin films deposited on 316 L stainless steel and silicon wafer substrates using the reactive RF/DC magnetron sputtering technique. The films' microstructure, morphology, thickness, roughness, and wettability were investigated experimentally and theoretically using density functional theory (DFT) calculations with the CASTEP program. X-ray diffraction analysis confirmed the formation of the fcc-TiAlN phase for coatings deposited at a DC power of 100 W, while increasing DC power to 150 W resulted in the appearance of a second phase, w-AlN. Field emission scanning electron microscopy images showed the formation of nanostructured coatings with a grain size range of 70–100 nm. The morphology of coatings was altered from a pyramid-like structure to a cauliflower structure by increasing the nitrogen amount in the N2/(Ar+N2) flow ratio. An increase in aluminum amount by increasing the DC power to 150 W enhanced the deposition rate and thickness of the coatings. The coatings deposited at a high N2/(Ar+N2) flow ratio exhibited minor surface roughness attributed to the compact structure. The contact angles obtained from the fabricated Ti/TiN/TiAlN coatings ranged from 86.2° to 114.2°, demonstrating values higher than the contact angle of uncoated 316 L stainless steel, which measured at 82°. Theoretical analysis using DFT calculations with CASTEP provided a fundamental understanding of the thin films' electronic structure and properties, consistent with the experimental results. This study highlights the importance of combining practical and theoretical analyses for a comprehensive understanding of material properties and the design of materials for various applications.

The performance of polymeric insulators which are being used in high transmission and distribution lines in the arid desert climate of south Libya

Libya currently, Polymers have huge production and are therefore enormously used especially in electrical applications. In the overhead transmission and distribution lines polymeric insulators are used in large quantities. The environmentally or naturally induced degradation mechanisms are creating major problems for the electrical properties of these polymeric insulators. The current study was conducted by the author in order to determine the condition of non-ceramic insulators that various power companies in Libya use. This experimental research was done to investigate the suitability of these polymeric insulators. The primary aim was to assess the performance of polymeric insulators which are being used in high transmission and distribution lines in the arid desert climate in the southern Al-Jufra region in Libya. The impacts of enormous heat and ultraviolet radiations on these polymeric insulators were studied. The accelerated aging test chamber was specially designed to achieve the objectives. The aging insulators' electrical strength (withstand) was then compared with the new polymeric insulators. The Dielectric performance indicated that Thermoplastic Elastomers (TPE) insulators overtake the Silicon Rubber (SiR) insulators. Correspondingly an optical result shows that the surface roughness of the aged sample in the SiR case is more in contrast with the new insulators. However, very minor surface roughness was found in the case of aged TPE insulators over the equivalent aging period. The enhanced surface roughness of aged SiR Insulators might impact the dielectric performance after their exposure for a lengthy period in local environmental conditions.