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The lack of suitable p-type dopant for β-Ga2O3 remains a hurdle for vertical power device applications. Epitaxy of GaN on Ga2O3 substrates was demonstrated as an alternative. (–201)-oriented β-Ga2O3 was converted into (0001)-oriented hexagonal GaN via nitrogen plasma in a plasma-assisted molecular beam epitaxy chamber, as verified by XRD and RHEED. The resulting nitridated GaN layers were characterized by TEM, x-ray reflectivity, and AFM to relate the nitridation conditions to crystallinity, layer thickness, and surface roughness. The crystallinity of subsequently grown epitaxial GaN films was quantified via XRD rocking curves and related to the nitridation layer properties across varying nitridation conditions. Specifically, the effect of the grain size and nitridation layer thickness was investigated to determine their role in threading screw dislocation management. [ABSTRACT FROM AUTHOR]

The experimental study of the angle-resolved hemispherical light scattering by V 4 O 7 film within a broad temperature range across metal–insulator transition reveals complex structural reorganization of the film deposited on the c-cut sapphire crystal. The bidirectional scattering distribution function and the surface autocorrelation function were obtained from scattering data to visualize statistics of the spatially resolved contributions of optical inhomogeneities in normal and lateral directions to the surface. The measurements reveal an anisotropic surface roughness distribution due to the twinned domain structure, with significant anisotropy changes across the phase transition. The V 4 O 7 film deposited on sapphire leads to a polydomain structure, minimizing elastic strain energy with distinct multiscale distributions of surface domains. Near T c , the material shows the lowest roughness but the highest lateral disorder of the surface. [ABSTRACT FROM AUTHOR]

Hafnium diboride (HfB2) is a promising candidate as a seed layer for GaN growth on Si substrates due to its excellent lattice and thermal coefficients matching with both materials. This work investigates the epitaxial growth of AlB2-type non-stoichiometric HfB2 (HfB2+δ with −0.1 < δ < 0.6) thin films on Si(111) using magnetron co-sputtering. We demonstrated that the process temperature significantly affected the surface roughness (RRMS ∼ 0.5–4 nm), film composition, and the nucleation of secondary impurity phases. Films deposited between 700 and 900 °C exhibit epitaxial growth on the Si substrate with a well-defined relationship of (0001) HfB 2 ‖ (111) Si and [ 11 2 ¯ 0 ] HfB 2 ‖ [ 1 1 ¯ 0 ] Si . Detailed x-ray diffraction and scanning transmission electron microscopy analyses reveal that impurity phases detected at high temperatures are primarily carbon-rich phases, identified as HfCx or HfCxBy. Interestingly, this secondary phase's crystal orientation follows the orientation of its surroundings. The different findings in terms of contamination (C and O) and deposition temperature offer valuable insights for further growth optimizing of high-quality epitaxial HfB2 thin films on Si(111) for future GaN-on-Si integration. [ABSTRACT FROM AUTHOR]

Purpose: To compare the color dimensions, color discrepancies (E00), and surface roughness of milled materials before and after application of a bleaching agent. Materials and Methods: A total of 10 extracted molars were obtained. Each tooth was cut in transverse sections to create disks (3-mm thick, 10-mm diameter; control group). Disk specimens of eight materials (n = 10 per group) were fabricated: polymethyl methacrylate (PMMA) interim material (PMMA-Telio group), two resin nanoceramics (RNC-Ultimate group and RNC-Cerasmart group), two hybrid ceramics (HC-Shofu group and HC-Enamic group), lithium disilicate (LD-Emax group), zirconia-reinforced glass ceramic (ZGC-Suprinity group), and zirconia (Zr-InCeram group). Color measurements were obtained using a spectrophotometer before and after applying 35% hydrogen peroxide-based bleaching agent. Pre- and postbleaching surface roughness (Sa) analyses were completed using a profilometer. Results: Significant L*, a*, b*, and E00 value differences were found (P < .05). Color discrepancies (E00) ranged from 0.30 ± 0.14 to 4.82 ± 0.10. The highest color discrepancies were measured on the PMMA-Telio group, while the lowest color discrepancies were computed for ZGC-Suprinity, RNCUltimate, and RNC-Cerasmart. Significant surface roughness differences were found (P < .05). The largest increase of surface roughness values between the pre- and postbleaching measurements was obtained in the PMMA-Telio group with a mean Sa value of 4.73 ± 3.02, while the largest decrease of surface roughness values between the pre- and postbleaching measurements was obtained in the Zr-InCeram group with a mean Sa value of -1.58 ± 0.10. Conclusions: The milled materials showed significant pre- and postbleaching color and surface roughness discrepancies. [ABSTRACT FROM AUTHOR]

Nonpolar (100), polar (002), semipolar (101), and nonpolar (110) preferred oriented ZnO films were synthesized by regulated growth using the chemical bath deposition method. The crystallinity, surface morphology, and optical properties of ZnO films with different preferred orientations after annealing in different atmospheres were systematically investigated. The experimental results show an increase in crystallinity and a decrease in surface roughness of the films after annealing; in particular, the optical transmittance of semipolar (101) preferred oriented ZnO films was significantly higher than that of the other samples. XPS and PL spectra confirmed that annealing in argon effectively increased donor defects, whereas annealing in oxygen and ozone reduced donor defects in the films, and that ozone annealing was best suited to enhance acceptor defects in nonpolar (110) preferred oriented ZnO films. Argon annealing is the best for the enhancement of donor defects in polar (002) preferred oriented ZnO films. This work achieves modulation of optical properties and defects of ZnO films by annealing in different atmospheres, which provides new ideas for the application of ZnO materials. [ABSTRACT FROM AUTHOR]

Recently, deep-ultraviolet (DUV) light-emitting devices have attracted attention for various applications. GaN/AlN superlattices have emerged as a promising alternative for achieving high-efficiency DUV emission. To fabricate superlattices with high crystal quality and abrupt interfaces, we have utilized face-to-face-annealed sputter-deposited AlN template substrates characterized by a flat surface and low dislocation density. Furthermore, radio-frequency plasma-assisted molecular beam epitaxy with in situ reflection high-energy electron diffraction monitoring was employed for the growth process. The growth of the superlattices follows a specific sequence. Step 1: AlN growth, Step 2: conversion of Al droplets to AlN, Step 3: GaN growth, and Step 4: evaporation of Ga droplets. This study explored the impact of GaN thickness on the GaN/AlN superlattice. The GaN thickness was linearly controlled by changing the duration of Step 3. This approach allowed for the growth of a flat GaN layer up to 1 monolayer (ML) and achieved superlattices with abrupt interfaces. Single-peak cathodoluminescence (CL) emission at 240–245 nm was observed from the superlattices, with the peak shift toward longer wavelengths as the GaN thickness increased. In contrast, quantum dot-like GaN islands were generated with a thickness of over 1 ML, induced by compressive strain. Superlattices with thicker GaN exhibited broad CL emission with multiple peaks. However, the AlN barrier layer reduced the surface roughness and maintained abrupt interfaces within the superlattices. Therefore, to obtain sharp single-peak UV emission from GaN/AlN superlattices, the growth sequence should be controlled to obtain flat GaN layers without dots. [ABSTRACT FROM AUTHOR]

Achieving high material perfection in aluminum (Al) films and their associated Al/AlOx heterostructures is essential for enhancing the coherence time in superconducting quantum circuits. We grew Al films with thicknesses ranging from 3 to 30 nanometers (nm) epitaxially on sapphire substrates using molecular beam epitaxy (MBE). An integral aspect of our work involved electron-beam (e-beam) evaporation to directly deposit aluminum oxide (Al2O3) films on the freshly grown ultrathin epitaxial Al films in an ultra-high-vacuum (UHV) environment. This in situ oxide deposition is critical for preventing the oxidation of parts of the Al films, avoiding the formation of undesired native oxides, and thereby preserving the nm-thick Al films in their pristine conditions. The thicknesses of our Al films in the study were accurately determined; for example, coherence lengths of 3.0 and 20.2 nm were measured in the nominal 3.0 and 20 nm thick Al films, respectively. These Al films were epitaxially grown on sapphire substrates, showing an orientational relationship, denoted as Al (111) ⟨ 2 1 ¯ 1 ¯ ⟩ ∥ sapphire (0001) [ 2 1 ¯ 1 ¯ 0 ]. The Al/sapphire interface was atomically ordered without any interfacial layers, as confirmed by in situ reflection high-energy electron diffraction (RHEED) and cross-sectional scanning transmission electron microscopy (STEM). All sample surfaces exhibited smoothness with a roughness in the range of 0.1–0.2 nm. The Al films are superconducting with critical temperatures ranging from 1.23 to around 2 K, depending on the film thickness. [ABSTRACT FROM AUTHOR]

In additive manufacturing processes such as laser powder bed fusion, the build orientation and packing of components affect the required support structures, the number of parts in each build, and the surface roughness of the printed parts, among other factors. Maximising the packing density while minimising the build height can increase effective machine utilisation and decrease per-part cost. Yet, the build layout optimisation problem is highly nonlinear and difficult to solve using human intuition, so a systematic algorithm approach is required. Here, we present and demonstrate a voxel-based analysis method with Bayesian optimisation for determining component build orientation in additive manufacturing. We introduce selected case studies incorporating exemplary process attributes of laser powder bed fusion, including the determination of orientation and packing configurations based on support removal and tool-accessibility constraints. [ABSTRACT FROM AUTHOR]

Surface pattern formation of Smart Cut™ silicon-on-insulator (SOI) substrates is investigated using a new process derived from this technology. The local control of SOI surface roughness is achieved by using hetero-temperature surface activated bonding to introduce locally bespoke shear stresses into bonded silicon wafers. The finite element method is used to back up experimental measurements of these large deformations to determine the amount of shear stresses introduced into the structure, and to determine its impact on the fracture mechanism. [ABSTRACT FROM AUTHOR]

Investigating the phonon-surface scattering mechanism is essential for the evaluation of thermal transport in nanostructures. The theoretical description to quantify this mechanism remains to be developed at the atomic scale. This work presents a phonon wave packet method to study the phonon-surface scattering behavior at rough surfaces. We obtain the specularity distribution dependent on phonon polarization, wavelength, and surface roughness. The reflection of the diffuse wave packet is primarily attributed to the surface shadowing effect at a higher incident angle, surface disorder, and surface-induced localized modes. Taking the wavevector-dependent specularity data as input, the thermal conductivity of silicon nanowires is calculated based on the Boltzmann Transport Equation. Our specularity model provides an accurate evaluation for predicting thermal conductivity. This work offers an atomic-level analysis for phonon-surface interaction, which is helpful for the understanding of thermal transport in nanostructures. [ABSTRACT FROM AUTHOR]

This study investigates the interface between ice and organic solvents using atomic force microscopy (AFM). Atomically flat ice surfaces were prepared and observed by AFM in 1-octanol, 1-hexanol, and 1-butanol. The results show differences in surface roughness influenced by the interaction of ice and alcohols. Young's modulus of ice was analyzed by force curve measurements, providing valuable insights into the properties of ice in liquid environments. The results showed the characteristics of the ice surface in different solvents, suggesting potential applications in understanding surface and interface phenomena associated with ice under realistic conditions. [ABSTRACT FROM AUTHOR]

Purpose: To propose and evaluate standardized polishing protocols for in vitro experiments using a custommade apparatus under controlled force to create consistent surface roughness on titanium and zirconia discs. Materials and Methods: A total of 160 discs were manufactured with a diameter of 10 mm, 80 titanium (Ti) and 80 zirconium oxide (Zr). Specimens were categorized into two groups: controlled force (CF) and without controlled force (WCF). Specimens in the CF group were polished with a custom apparatus incorporating a tension gauge on the Ti and Zr disc surfaces to achieve consistent roughness. The WCF group was polished without the use of a tension gauge. Each group had four subgroups (n = 10): control/machined with no polishing (C), rough (R), smooth (S), and very smooth (VS). The subgroups were processed using a sequence of diamond-impregnated polishing burs and polishing paste. Results: The CF group showed consistent surface roughness and a gradual decrease in surface roughness. Control in Ti (Ra = 6.5 ± 0.03 µm) and in Zr (Ra = 5.4 ± 0.04 µm); R in Ti (Ra = 3.5 ± 0.06 µm) and in Zr (Ra = 3.2 ± 0.07 µm); S in Ti (Ra = 1.5 ± 0.04 µm) and in Zr (Ra = 1.1 ± 0.06 µm); and VS in Ti (Ra = 0.05 ± 0.002 µm) and in Zr (Ra = 0.02 ± 0.005 µm). There were significant differences for R, S, and SV under CF and WCF in Ti and Zr surfaces. Conclusions: The specimens polished under control force produced significantly more uniform surface roughness than those polished without controlled force and were produced with a higher degree of consistency. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of finishing, polishing, and glazing on the roughness, flexural strength, and microstructure of lithium disilicate glass-ceramics. Materials and Methods: LD CAD/CAM blocks were cut into 96 discs (1.2 x 12 mm). After crystallization, a layer of glaze was applied to the discs' surfaces. The specimens were randomly divided into eight groupsn = 12) for different surface treatments (glaze [G], diamond abrasion [D], find diamond abrasion [F], and polishing [P]): G(glaze, control), GD, GDG, GDP, GF GFG, GFP, and GDFP. Mean roughness (Ra), mean square height (Rq), and maximum roughness (Rz) were measured. The biaxial flexural strength test was performed in a universal testing machine at 0.5 mm/minute. Microstructural analysis was performed using x-ray diffraction patterns (XRD). Differences on the roughness obtained in distinct groups was analyzed with Kruskal-Wallis and Bonferroni tests (α = .05). The flexural strength tests were compared with one-way ANOVA. Results: Glazed groups (G, GDG, and GFG) presented the lowest surface roughness, lower crystallinity, and higher flexural strength than the other groups. Although polishing and glaze presented similar surface roughness, polishing protocol decreased the flexural strength compared to the control group G. Conclusions: Clinically adjusted LD glass-ceramic restorations should be reglazed whenever possible to improve strength. [ABSTRACT FROM AUTHOR]

We present diamond-like carbon (DLC) conversion surfaces to detect particles with energy below 2 keV. Conversion surfaces have been widely applied in measurements of low-energy particles by instruments onboard planetary and heliophysics missions. Their effectiveness is characterized by the efficiency in changing the charge state of the incident particles while maintaining a narrow angular distribution for the reflected particles. DLC as a conversion surface coating material has high conversion efficiency. We developed a conversion surface production process that provides ultra-smooth and ultra-thin DLC conversion surfaces. The process includes substrate preparation through precision cleaning, plasma immersion ion deposition of the DLC film, and diagnostics of the film parameters. The latter includes the measurement of the coating thickness, surface roughness, and the conversion efficiency for ion beams with energy below 2 keV. The process we developed provides the DLC conversion surface coating of repeatable parameters with a mean surface roughness of 3.4 ± 0.2 Å and a mean film thickness of 46.7 ± 0.8 nm uniform across the sample area. Ion beam measurements showed a negative ion yield of 1%–2% for hydrogen atoms and 8%–15% for oxygen atoms with an angular scatter distribution of 10°–20° at full width of half maximum. These results agree with those of other conversion surface coatings in the literature. The DLC conversion surfaces presented here are implemented in the conversion surface subsystem of the Interstellar Mapping and Acceleration Probe (IMAP)-Lo instrument of the IMAP mission scheduled for launch in 2025. [ABSTRACT FROM AUTHOR]

Coarse-grained (CG) molecular models greatly reduce the computational cost of simulations allowing for longer and larger simulations, but come with an artificially increased acceleration of the dynamics when compared to the parent atomistic (AA) simulation. This impedes their use for the quantitative study of dynamical properties. During coarse-graining, grouping several atoms into one CG bead not only reduces the number of degrees of freedom but also reduces the roughness on the molecular surfaces, leading to the acceleration of dynamics. The RoughMob approach [M. K. Meinel and F. Müller-Plathe, J. Phys. Chem. B 126(20), 3737–3747 (2022)] quantifies this change in geometry and correlates it to the acceleration by making use of four so-called roughness volumes. This method was developed using simple one-bead CG models of a set of hydrocarbon liquids. Potentials for pure components are derived by the structure-based iterative Boltzmann inversion. In this paper, we find that, for binary mixtures of simple hydrocarbons, it is sufficient to use simple averaging rules to calculate the roughness volumes in mixtures from the roughness volumes of pure components and add a correction term quadratic in the concentration without the need to perform any calculation on AA or CG trajectories of the mixtures themselves. The acceleration factors of binary diffusion coefficients and both self-diffusion coefficients show a large dependence on the overall acceleration of the system and can be predicted a priori without the need for any AA simulations within a percentage error margin, which is comparable to routine measurement accuracies. Only if a qualitatively accurate description of the concentration dependence of the binary diffusion coefficient is desired, very few additional simulations of the pure components and the equimolar mixture are required. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the effect of disinfectants on the roughness and mechanical properties of CAD/CAM polymethylmethacrylate (PMMA) dentures. Materials and Methods: Two groups of denture base resins were tested--heat-polymerized and milled blocks. For each resin, 120 specimens were produced for flexural strength (FS) and flexural modulus (FM) analyses (total: 240 specimens), and 40 were produced for microhardness and surface roughness evaluations (total: 80 specimens). They were categorized into the following groups based on immersion: control (deionized water); H1 (1% sodium hypochlorite); H05 (0.5% sodium hypochlorite); and C2 (2% chlorhexidine) groups. The immersion periods were 0 (T0), 130 (T1), and 260 (T2) cycles. Statistical analyses were performed for flexural properties using threeway ANOVA. Microhardness (KHN) and surface roughness (Ra) were analyzed using repeated-measures ANOVA. A significance level of 5% was set. Results: CAD/CAM PMMA showed higher FS (P = .001) and FM (P < .001) than conventional PMMA. The KHN value was superior to the conventional PMMA (P < .001). The chemical solution affected the surface roughness of both resins (P = .007). The CAD/CAM PMMA block showed increased Ra values when H1 was used. Cycling separately increased the FS of conventional PMMA (T1 vs baseline; P < .05). However, the FM of CAD/CAM PMMA was higher (T1 and T2 vs baseline; P < .05). The time factor increased the microhardness of both resins (T2 vs baseline; P < .05). Conclusions: The CAD/CAM resin showed higher values compared to conventional PMMA in all tests, regardless of the chemical solution used; however, the values obtained for both resins were clinically acceptable. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of different finishing protocols on the wear behavior of lithium disilicate glass-ceramics (LD). Materials and Methods: Specimens were produced from LD prefabricated CAD/CAM blocks and divided into three groups according to the surface treatment (n = 8): control, polishing, and glaze. Ceramic specimens were subjected to wear testing using a dual-axis chewing simulator. A 49-N load was applied in the axial direction combined with a lateral movement (1-mm path) using an LD spherical piston for a total of 106 cycles. Qualitative analysis of the wear surface was performed using an optical microscope. Quantitative analysis of surface roughness and volume loss was performed using a confocal microscope and a 3D-image editing software, respectively. Surface roughness and volume loss data were analyzed using Friedman's nonparametric statistical test for repeated measures and the Student-Newman-Keuls test (a = .050). Results: There were statistical differences for surface roughness and volume loss of LD specimens in the different experimental conditions (P < .001). The control and polishing groups showed similar surface roughness and volume loss values for all testing times. The glaze group had greater wear volume after 103, 104, and 105 cycles. After 106 cycles, surface roughness and volume loss were similar in all groups. For the piston, surface roughness was similar over time and among groups. Conclusions: A distinct wear behavior was found for glazed glass-ceramic specimens compared to control and polished specimens. At the end of the simulation, the surface roughness and volume loss was similar for the groups. [ABSTRACT FROM AUTHOR]

Copper (Cu) interconnections have been widely used in advanced electronic packaging due to their outstanding thermal and electric properties. Preparing a smooth and uniform Cu seed thin layer is one of the critical processes to obtain high-reliability Cu interconnections. The barrier layer between Cu and silicon (Si) devices is necessary to prevent the inter-diffusion between Cu and Si. However, little work has been done on the surface roughness analysis of the Cu seed layer deposited on the diffusion barrier layer. In this paper, the influences of deposition thickness, incident energy, barrier layer temperature, and surface morphology on the surface roughness of the Cu seed layer deposited on α-titanium (α-Ti) barrier layer were studied in detail by the molecular dynamics (MD). The simulation results indicated that appropriate parameters have a beneficial effect on reducing the surface roughness, and the surface morphology of the Cu seed layer strongly connects with that of the barrier layer. These results provided a foundation for optimizing the quality of the Cu seed layer. [ABSTRACT FROM AUTHOR]

We have measured the absolute doubly differential angular sputtering yield for 20 keV Kr+ impacting a polycrystalline Cu slab at an incidence angle of θi = 45° relative to the surface normal. Sputtered Cu atoms were captured using collectors mounted on a half dome above the sample, and the sputtering distribution was measured as a function of the sputtering polar, θs, and azimuthal, ϕs, angles. Absolute results of the sputtering yield were determined from the mass gain of each collector, the ion dose, and the solid angle subtended, after irradiation to a total fluence of ∼1 × 1018 ions/cm2. Our approach overcomes shortcomings of commonly used methods that only provide relative yields as a function of θs in the incidence plane (defined by the ion velocity and the surface normal). Our experimental results display an azimuthal variation that increases with increasing θs and is clearly discrepant with simulations using binary collision theory. We attribute the observed azimuthal anisotropy to ion-induced formation of micro- and nano-scale surface features that suppress the sputtering yield through shadowing and redeposition effects, neither of which are accounted for in the simulations. Our experimental results demonstrate the importance of doubly differential angular sputtering studies to probe ion sputtering processes at a fundamental level and to explore the effect of ion-beam-generated surface roughness. [ABSTRACT FROM AUTHOR]

Models have historically represented fractured porous media with continuum descriptions that characterize the media using bulk parameters. The impact of small-scale features is not captured in these models, although they may be controlling the performance of subsurface applications. Pore-scale models can simulate processes in small-scale features by representing the pore space geometry explicitly but are computationally expensive for large domains. The alternative multiscale approach entails the combination of pore-scale and continuum-scale descriptions in a single framework. We use Chombo-Crunch, a computational capability that discretizes complex geometries with an adaptive embedded boundary method to contrast these two approaches. Chombo-Crunch takes advantage of recent computational performance and memory bandwidth improvements resulting from the emergence of exascale computing resources. These combined improvements enable the efficient simulation of reactive transport in fractured media with a high degree of fidelity and the ability to capture the control small-scale processes exert on the overall medium evolution.

Hydrophobicity has proven fundamental in an inexhaustible amount of everyday applications. Material hydrophobicity is determined by chemical composition and geometrical characteristics of its macroscopic surface. Surface roughness or texturing enhances intrinsic hydrophilic or hydrophobic characteristics of a material. Here we consider crystalline surfaces presenting molecular-scale texturing typical of crystalline porous materials, e.g., metal-organic frameworks. In particular, we investigate one such material with remarkable hydrophobic qualities, ZIF-8. We show that ZIF-8 hydrophobicity is driven not only by its chemical composition but also its sub-nanoscale surface corrugations, a physical enhancement rare amongst hydrophobes. Studying ZIF-8's hydrophobic properties is challenging as experimentally it is difficult to distinguish between the materials' and the macroscopic corrugations' contributions to the hydrophobicity. The computational contact angle determination is also difficult as the standard "geometric" technique of liquid nanodroplet deposition is prone to many artifacts. Here, we characterise ZIF-8 hydrophobicity via: (i) the "geometric" approach and (ii) the "energetic" method, utilising the Young–Dupré formula and computationally determining the liquid–solid adhesion energy. Both approaches reveal nanoscale Wenzel-like bathing of the corrugated surface. Moreover, we illustrate the importance of surface linker termination in ZIF-8 hydrophobicity, which reduces when varied from sp3 N to sp2 N termination. We also consider halogenated analogues of the methyl-imidazole linker, which promote the transition from nanoWenzel-like to nanoCassie–Baxter-like states, further enhancing surface hydrophobicity. Present results reveal the complex interface physics and chemistry between water and complex porous, molecular crystalline surfaces, providing a hint to tune their hydrophobicity. [ABSTRACT FROM AUTHOR]

Epitaxial Mn-doped indium tin oxide (ITO) films were deposited on single-crystal yttria stabilized zirconia (YSZ) substrates with (111), (110), and (100) crystal plane orientations using RF magnetron sputtering. The epitaxial relationship between the Mn-doped ITO films and the YSZ substrates was studied using x-ray diffraction (XRD) patterns in the ω–2θ scan mode and XRD pole figures. The Mn-doped ITO films on the YSZ(111) and YSZ(110) substrates exhibited a higher degree of crystallinity than the film on the YSZ(100) substrate as per the x-ray rocking curves. Fluctuations in the crystalline alignment were found to significantly influence the electrical properties of Mn-doped ITO films. Ferromagnetic hysteresis loops were observed at room temperature for all the epitaxial Mn-doped ITO films, irrespective of their crystallographic orientation. The magnetic properties of the epitaxial Mn-doped ITO films suggest that a combination of delocalized charge carrier-mediated interaction and bound magnetic polaron-driven interaction is required to explain the origin of ferromagnetism in these films. The Mn-doped ITO film on the YSZ(111) substrate exhibited the most desirable characteristics in terms of crystallinity, surface smoothness, electrical conductivity, and magnetic properties. [ABSTRACT FROM AUTHOR]

High-volume fraction silicon carbide particle-reinforced aluminum matrix (SiCp/Al) composites are crucial materials in the aerospace industry, requiring precision milling to ensure accurate mating surfaces. However, achieving low-damage machining of SiCp/Al remains challenging. Traditional dry machining methods often affect surface integrity, while minimum quantity lubrication (MQL) has emerged as a more sustainable alternative to flood cooling. Despite this, the tool's air barrier layer in MQL limits the lubricant flow to the tool-workpiece interface, reducing cooling and lubrication efficiency. To overcome this, an ultrasonic-enabled MQL (UV-MQL) technique for milling SiCp/Al is proposed. However, research on the effects and mechanisms of ultrasound-enabled nanolubricants in the milling of SiCp/Al composites remain limited. To fill this gap, milling experiments were conducted under various cooling and lubrication conditions. The performance of UV-MQL was assessed using key parameters such as milling force, specific cutting energy, and surface topography. Results showed that UV-MQL and UV-NMQL reduced specific cutting energy by 25.44% and 32.55%, respectively, compared to conventional MQL milling, while surface roughness (Sa values) decreased by 14.44% and 38.22%. To further explain these outcomes, the anti-friction mechanism of the ultrasonically enabled nanolubricant was analyzed, focusing on droplet wetting, penetration, and film formation. These findings provide valuable insights for improving surface integrity in the SiCp/Al milling process. [ABSTRACT FROM AUTHOR]

In the present study, a novel multivariate grey model called the GM(1,N|sin) power model was used to forecast metal removal rate, surface roughness and microhardness in nitrogen gas–liquid mixed electrical discharge machining. Tests were performed at various current levels, duty cycles and gas pressures and experimental data including metal removal rate, surface roughness and microhardness were collected. A novel periodic bidirectional tool rotation was added to the experimentation. The effect of process parameters on metal removal rate, surface roughness and microhardness was explored through analysis of variance and microstructural tests. The findings revealed that both current and gas pressure have a significant effect on the experimental results. When nitrogen is added to the base metal, hard intermetallic phases are formed within the alloy, resulting in strengthening. The nitrogen in the base metal caused fine and uniform grains and increased microhardness. Periodic bidirectional tool rotation resulted in sufficient dielectric fluid being transmitted to the machining zone to flush debris out of the machining zone and reduce surface defects. The grey model GM(1,N|sin) power model combined the sinusoidal function and power exponential to address nonlinear and periodic oscillation relationships between input and output variables. An accumulation generation operator and mean were introduced in this model and reduced uncertainty in the system. The performance of the GM(1,N|sin) power was measured by estimating the MAE, RMSE and R2 values of 0.0765, 0.0853 and 0.9836 for MRR; 0.033, 0.0391 and 0.9874 for surface roughness; and 11.5806, 13.743 and 0.9739 for microhardness, respectively. These results indicated that the suggested model had a high degree of prediction accuracy. Consequently, the model proves to be an effective approach for solving nonlinear problems. [ABSTRACT FROM AUTHOR]

In this work, the cost-effective precision finishing of electroless nickel plating using a compliant tool is presented. The shape adaptive grinding (SAG) process with diamond abrasive polishing pad is used for finishing of a plated surface on a stainless-steel substrate. The variable parameters in the SAG are tool compression, rotational speed of the tool, and particle size of diamond abrasive pads (9, 15, and 30 µm). Forces acting on the workpiece and areal surface roughness are the output parameters. Diamond abrasive pads are characterized for particle distribution and topography. Detailed topographical analysis of abrasive pads provides a better understanding of the change in surface characteristics and material removal mechanism with the different abrasive sizes. It is observed that fine diamond abrasive pads generate low surface roughness, while medium and coarse pads have higher wear resistance. The final finishing is performed at the optimal process parameters, and the final areal surface roughness of 7 nm is achieved. The topography, morphology, and wettability of the surface after finishing are analysed to correlate the effect of operating conditions. The article also highlights the pad loading and abrasive wear that significantly affect the outcome of the polishing process. [ABSTRACT FROM AUTHOR]

The cooling time in injection molding is defined as the period during which the molten plastic in the mold solidifies and cools to a temperature suitable for safe ejection without deformities. Efficient cooling is crucial for large-volume production in the plastic injection molding industry. This study investigates the cooling performance of rapid tooling made from aluminum-filled epoxy resin with varying inner cooling channel surface roughness. This study includes creating a microstructure on the cooling channel surface to assess its impact on cooling efficiency. The study produces rapid tooling with both parallel and series cooling channels. The average cooling time for molded wax patterns is lower with parallel cooling channels than serial cooling channels. Nanobubble coolant shortens the cooling time of molded wax patterns based on experiments of low-pressure wax injection molding. The average cooling time-saving ratio is about 15.4% from five low-pressure injection moldings using nanobubble coolant. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) refers to a novel group of manufacturing methods where the process takes place by gradually adding material to build the final part. AM offers significant advantages—enhanced design freedom and reduced material waste with the potential to change the paradigm of the manufacturing industry. Direct metal laser sintering (DMLS) is an additive manufacturing method where 3D printing of metal parts is conducted layer by layer from metallic powders. DMLS-hybrid milling is a new addition to additive manufacturing methods. The synergistic approach of additive and subtractive manufacturing methods offers benefits from both manufacturing paradigms. The process parameters—laser power, print speed, layer thickness, hatch distance, etc.—significantly influence the quality of the final part. Hence, the process parameters should be optimized to obtain the desired result. This work focuses on optimizing process parameters for superior surface characteristics and mechanical properties of heat-treated maraging steel manufactured by the DMLS-hybrid milling method. Experimental approaches were adopted, and statistical analyses were performed to evaluate the performance of maraging steel parts printed at multiple process conditions guided by Taguchi L9 orthogonal array of experiment design. Significant improvement was observed in surface quality by adopting milling operation during printing, and mechanical properties were improved by the heat-treatment process. [ABSTRACT FROM AUTHOR]

SiC-ZrC based ceramics have caught much attention as coatings for graphite materials. However, the coefficient of thermal expansion (CTE) mismatch between coatings and matrix severely limits their application in harsh environments. Herein, we proposed a non-static pre-oxidation treatment under an air pressure of 0.05 MPa to increase the surface roughness of graphite matrix to 18.054 μm and then prepared the SiC-ZrC/SiC multilayer coating on the pre-oxidized graphite. The results demonstrate that a firm interlocking structure was formed between SiC-ZrC/SiC multilayer coating and graphite matrix, which effectively improved the bonding strength and enhanced the cyclic ablation resistance of coatings. The bonding strength of SiC-ZrC/SiC multilayer coated on graphite pre-oxidized under negative pressure was 5.70 ± 0.42 MPa, which was 54.89 % higher than that on graphite pre-oxidized under atmospheric pressure (3.68 ± 0.08 MPa). After the plasma ablation for 360 s (60 s × 6), the linear and mass ablation rates of SiC-ZrC/SiC multilayer coated graphite which was pre-oxidized under negative pressure were −0.083 μm/s and 0.101 mg/s, respectively. [ABSTRACT FROM AUTHOR]

Ultrasonic gauging and defect detection of metallic pipes is a multi-disciplinary task, as it has to be performed in situ and involves several difficulties due to their curvature, limited access and corroded/eroded surface roughness due to harsh operating conditions. This research paper focuses on the investigation of employing a focused piezoelectric transducer in an immersion pulse-echo (PE) mode to measure the wall thickness (WT) from the inner side of the metallic pipes and to detect defects in the pipes. This paper also provides advances for understanding ultrasonic wave propagation in metallic pipes by simulation study using modern finite element technology and validating the results experimentally using battery-operated, water-immersible, IP67-grade stand-alone two-channel ultrasonic instrumentation that can move inside the pipe under test in flowing liquids such as water or oil. A simulation model has been established for time-of-flight (TOF) measurements for metallic pipes with various wall thicknesses, detection of standard defects and wall-thinning by inspecting the inner diameter (ID) surface of pipes and the pipe filled with water. The simulated results for the metallic pipes are in good agreement with the experimental data, providing an accurate and quantitative assessment of WT in the presence or absence of defects. [ABSTRACT FROM AUTHOR]

Titanium alloys are challenging to manufacture because the thin chips create a small surface area between the cutting tool and the workpiece. High cutting temperatures are a result of titanium alloys' inadequate heat conductivity and excessive stress created by the narrow contact area. This study focuses on the optimisation of the impact on tool life, surface roughness, crater wear, and flank wear. The process variables for turning Ti-6Al-4 V alloy take tool life, surface roughness, crater wear, and flank wear into consideration. Results were analysed using Taguchi-based SAW, VIKOR, TOPSIS, and Electre techniques. The outcomes of the experiment demonstrate that Ti-6Al4V alloy has been successfully turned using CIMCOOL 360 coolant with a 15% concentration. By selecting the best alternative at a cutting speed = 80 rpm, feed rate = 0.18 mm/rev, depth of cut = 0.12 mm, and a rake angle = 14 degrees, where the surface roughness and tool life are, respectively, 0.716 m and 48.3998 min, the research work shows the importance of the suitability of TOPSIS in solving the Multiple Criteria Decision-Making (MCDM). From the ANOVA results, for surface finish, it is noticed that the process parameter rake angle is having Rank 01 for all levels. Thus, the rake angle is the major influencing parameter to achieve a better quality of surface roughness. While in the case of flank wear it is crystal clear that the process parameter DOC is having Rank 01 for all levels. Thus, DOC is the most influencing parameter to achieve lesser flank wear and better quality of tool life. [ABSTRACT FROM AUTHOR]

Introduction: The use of oral anticancer medications has become more prevalent in cancer therapy. This is particularly the case in the management of advanced non-small cell lung cancer (NSCLC). However, when the treatment delivery interaction between the patient and the healthcare provider is removed, the risk of non-adherence increases. Insights into patient preferences can allow drug product formulation scientists to design more patient-centric medications that may promote an increase in adherence which, in turn, may lead to more beneficial health outcomes. Methods: We conducted an advisory board with patients with NSCLC in the United Kingdom to elicit and understand preferences for drug product attributes related to appearance, instructions, and modality. The advisory board was preceded by a quantitative preference survey that included three object-case best–worst scaling exercises and was followed by administering the same survey to a broader group of patients to confirm the results. Results: Patients strongly prefer once-daily dosing over more frequent dosing, regardless of the number of pills because taking tablets or capsules multiple times each day can disrupt daily activities. In addition, patients place high importance on surface smoothness because a rough surface implies decreased swallowability. Finally, food restrictions involving directions regarding taking medication with or without food represent difficulties for patients with cancer. Results of the follow-up survey confirmed these results. Conclusions: Drug developers should attempt to limit the dosing of these medications to once-daily regimens, avoid surface roughness, and develop formulations that can be taken without regard to the timing of meals to the greatest extent possible. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel network‐based approach for reconstructing signed distance functions from fluid particles. The method uses a weighting kernel to transfer particles to a regular grid, which forms the input to a convolutional neural network. We propose a regression‐based regularization to reduce surface noise without penalizing high‐curvature features. The reconstruction exhibits improved spatial surface smoothness and temporal coherence compared with existing state of the art surface reconstruction methods. The method is insensitive to particle sampling density and robustly handles thin features, isolated particles, and sharp edges. [ABSTRACT FROM AUTHOR]

A newly synthesis composite thin films of poly(vinyl chloride) has been refinement with ionic liquid, where PVC dissolved in THF with various concentrations of IL by casting method to form the composite thin films, without any reaction and IL dangles within PVC matrix. The thin films were examined by the diffusive reflectance device under the wavelength range (238–1300 nm). The XRD, EDX, and AFM techniques were utilized to discover the structure of the PVC matrix after additive IL. The XRD analysis illustrated the amorphous structure of the films, while the EDS analysis illustrated the main composition of pure PVC and composite PVC/IL. The optical properties and optical parameters were studied. The reflectance, extinction factor, transmittance, and imaginary dielectric constant declined, the absorption value was between (80–89 %), and the refractive index, real dielectric constant, and optical conductivity were increased. The indirect energy gap declined from 4.2 eV to 2.2 eV and the direct energy gap declined from 3.7 eV to 2.6 eV. The Urbach energy was increased from 2.09 eV to 15.45 eV revealing an increase in the disorders of electrons. The Ed increased from 23.42 eV to 70.68 eV and Eo increased from 7.00 eV to 10.88 eV. AFM analysis illustrated the roughness of the films increased after additive IL to the PVC Matrix from 1.08 nm to 4.45 nm and the root mean square of the particles ranged from 1.57 nm to 5.56 nm. The PVC composite thin films are utilized in solar cell and sodium-ion battery applications. [ABSTRACT FROM AUTHOR]

Femtosecond laser processing has become a critical technique for the microfabrication of hard and brittle materials, particularly in microfluidic device applications. This study focuses on the fabrication of microchannels with controllable cross-sectional profiles in silica glass, a material known for its excellent physical and chemical properties. Through a combination of experimental research and theoretical analysis, the surface generation mechanisms governing microchannel morphology are investigated, alongside the influence of various processing parameters on the surface roughness at the microchannel bottom. A comprehensive optimization method is developed to control sidewall taper and surface roughness by adjusting laser scanning paths and modes. Utilizing a composite scanning approach, the study achieves near-rectangular microchannels with average sidewall taper angles below 5° and surface roughness (Sa) of 2.53 μm. These results provide a new strategy for precise control of microchannel morphology in silica glass, offering significant potential to enhance the efficiency and precision of microfluidic device fabrication, with broad applications in both industrial and research settings. [ABSTRACT FROM AUTHOR]

Doped Hf 0.5 Zr 0.5 O 2 materials have drawn increasing attention due to the excellent ferroelectric properties, but the relevant research is just in the preliminary stage and the reported doped systems are rare. In this work, Ca doped Hf 0.5 Zr 0.5 O 2 (Ca:HZO) ferroelectric films were successfully fabricated via chemical solution deposition and investigated for the first time. It is observed that Ca doping induces a phase transformation from monoclinic to orthorhombic/tetragonal and then to monoclinic/tetragonal. The highest orthorhombic phase fraction is achieved in 2.5 mol% Ca doped HZO film, contributing to the optimum ferroelectric property with the largest remnant polarization of 14.00 μC/cm2 after 105 cycles. Additionally, the leakage current density is observed to decrease with increasing Ca content, which is mainly associated with the changes of grain size and surface roughness. As a result, the endurance is significantly improved in the Ca doped films, and an excellent endurance of 1010 cycles is achieved in the 2.5 mol% Ca doped film. These results suggest that Ca doping can enhance the ferroelectric and endurance properties of HZO films by optimizing the phase and morphological structure. [ABSTRACT FROM AUTHOR]

The low-cost, high-quality, and high-efficiency machining of the large-thickness ruled surface structure of difficult-to-machine materials, such as turbine disc mortise and blade tenon in aircraft engines, is still a great challenge for existing machining technology. Electrochemical cutting with radial electrolyte flushing emerges as a solution. This method involves using tube electrodes with array jet-flow holes to spray electrolyte radially into the machining gap, effectively cutting the workpiece. It promises not only the inherited benefits of wire electrochemical machining, like flexibility and no heat-affected layers, but also the capability to machine large thicknesses efficiently. Nevertheless, the technique faces a hurdle: the inconsistency in the surface topography due to the electrolyte flow field in the machined slit, impacting the machining quality. To address this, the method has been enhanced with axial supplementary electrolyte flushing. Simulation and experimental results indicate that this addition improves electrolyte flow in the machined slit, ensuring the electrolyte's renewal, which in turn rectifies the issue of inconsistent surface quality and enhances cutting quality without compromising efficiency. Optimization of the nozzle diameter and flow rate for the axial flushing has led to significant advancements. For instance, a fir-tree-shaped turbine disc mortise was precisely cut into a 20-mm-thick Inconel 718 plate at a feed rate of 5 µm/s, achieving a surface roughness of Ra 0.95 µm. [ABSTRACT FROM AUTHOR]

Titanium alloys are employed extensively in some vital areas like aerospace, biomedical, and automotive due to their exceptional properties. Nevertheless, conventional grinding to process high-strength titanium alloys can be problematic and lead to burns and wheel clogging. As a new grinding method, high-shear and low-pressure grinding can effectively avoid these problems. In this study, a body-armor-like abrasive disc based on the principle of liquid body armor was developed to achieve high-shear and low-pressure grinding. The material removal mechanism of high-shear and low-pressure grinding with body-armor-like abrasive disc was revealed. The effect of some grinding parameters, such as spindle rotational speed, rotary table speed, and tool offset, on surface roughness, material removal depth, and material removal rate of Ti-6Al-4V alloy was discussed. The surface roughness (Ra) was reduced by approximately 85.3% from 313.8 to 46 nm under the optimal grinding parameters. A material removal rate of 2.648 µm/min was achieved. The surface morphology of the Ti-6Al-4V alloy before and after grinding indicated that the surface defects were substantially removed, with a concomitant improvement in surface quality. The results showed that the body-armor-like abrasive disc can achieve high-quality and high-efficiency grinding for Ti-6Al-4V alloy. [ABSTRACT FROM AUTHOR]

Dielectric oil has been recently used in wire electrical discharge machining (wire EDM) for achieving high-precision machining. However, the influence of dielectric oil properties on wire EDM characteristics has not been clarified sufficiently. This study fundamentally investigated the influence of dielectric oil viscosity on wire EDM characteristics. In this study, three types of dielectric oil differing only in viscosity were prepared and examined. Linear cutting experiment results showed that the removal rate and the machined surface roughness increase with dielectric oil viscosity. Then, the influence of viscosity on crater removal volume was investigated to discuss the cause of the change in removal rate, and it was found that crater removal volume increases with the viscosity. Furthermore, CFD (computational fluid dynamics) analysis results and discharge observation results showed that the debris exclusion becomes worse in higher viscosity oil, and the discharge concentration occurs frequently, resulting in the deterioration in machined surface roughness. Next, the difference in machining accuracy with dielectric oil viscosity was investigated. It was found that the corner shape accuracy deteriorates with the increase of viscosity while the machined surface waviness and straightness improve slightly. Structural analysis results showed that wire deflection increases with viscosity, resulting in the deterioration in corner shape accuracy. On the other hand, high-speed observation of wire vibration was carried out, and it was found that the wire vibration decreases in the case of higher viscosity, which leads to the improvement in machined surface waviness and straightness. [ABSTRACT FROM AUTHOR]

In this study, a nanofluid ultrasonic atomization minimum quantity lubrication (MQL) system was employed for grinding and processing titanium alloy (Ti-6Al-4V). Nanoparticles in the nanofluid were dispersed through the ultrasonic atomization MQL system to improve the lubrication efficiency. This system is a grinding manufacturing innovation on lubrication technology. First, a robust design method optimizes the grinding parameters of force ratio, temperature, and surface roughness of each quality characteristic. Surface integrity is considered a key component metric in grinding. Therefore, various images of the grinding surface quality were collected to establish a complete titanium alloy grinding image database. The convolutional neural network (CNN) technique was used to establish a model with high accuracy and automatic recognition of the surface quality after grinding, which is classified as Good, Plowing, Crushing pits, and Bad. This study employed VGG-19, GoogLeNet, ResNet-50, and AlexNet for modeling and testing comparison. Different hyperparameter configurations will affect each model's learning speed and performance. Therefore, their hyperparameter optimizations were performed before establishing our CNN model for classification. After optimization, the average accuracy of the four models can be improved by 3.75–12%, which can quickly improve the performance of the CNN model systematically. This study verified and validated our model. The findings show that this research method can be used by the industry in the actual grinding process monitoring and identification of the grinding quality of Ti-6Al-4V. [ABSTRACT FROM AUTHOR]

Silicon nitride (Si3N4) is widely used in multiple fields due to excellent properties. However, the improvement of the mechanical properties by the existing processing is limited, and the surface modification mechanism of the material is not enough. Therefore, laser-assisted grinding (LAG), combing laser heating with grinding, is proposed. The LAG process is simulated by molecular dynamics (MD) simulation, and the Si3N4 grinding force, atom removal, damage mechanism, and residual stress are investigated. The machining surface hardness arrives at 1862.6 HV, higher than traditional grinding (TG). The grinding force and surface roughness are reduced by 53% and 25.6%, respectively. The study results promote high-performance fabrication of substrate surfaces while filling up the study of Si3N4 matrix removal and damage. [ABSTRACT FROM AUTHOR]