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Understanding the nucleation and growth of tungsten (W) is technologically important in spin-to-charge interconversion for realizing energy-efficient spintronic devices. Here, we have systematically investigated the effect of Ar deposition pressure (P A r ) on the nucleation and growth of W. The observed surface topography as a function of P A r reveals a microstructural transition from zone T to zone 1 in the structure zone model. The physical origin for the increasing roughness as a function of P A r correlates with the surface diffusion of adatoms and growth kinetics in the Volmer–Weber growth mechanism. Grazing incidence x-ray diffraction (GIXRD) results show that W exhibits a structural phase transition from a mixed phase of (α + β) - W to a single phase of β - W as a function of P A r . The analysis of the electron diffraction patterns obtained from the films grown on amorphous-SiNx windows also supports these observations. The observed transition is fundamentally correlated with the growth kinetics in zone T and zone I. Thickness-dependent GIXRD results qualitatively prove that the film grown in zone T exhibits compressive strain, whereas that grown in zone I exhibits only tensile strain. The critical thickness for the phase transition is strongly attributed to the strain during nucleation and growth. The increasing resistivity as a function of P A r corroborates the change in structural phases. Thickness-dependent resistivity measurements correlate with the degree of crystallinity via relative intensity observed from the GIXRD results. Our results strongly suggest that W structural phases can be deterministically controlled via P A r for developing low-power spintronic devices. [ABSTRACT FROM AUTHOR]

The engineering of the surface morphology and the structure of the thin film is one of the essential technological assets for regulating the physical properties and functionalities of thin film-based devices. This study presents an easy and handy approach to tailor the surface structure of epitaxial thin films utilizing low-energy ion beam. Here, we investigate the evolution of the surface structure and magnetic anisotropy (MA) in epitaxial Fe/MgO (001) model systems subjected to multiple cycles of ion beam erosion (IBE) after thin film growth. The growth of Fe film occurs in the form of three–dimensional islands and exhibits intrinsic biaxial MA. Following a few cycles of IBE, an induced uniaxial magnetic anisotropy leads to a split in the hysteresis loop, and the film displays almost uniaxial magnetic switching behavior. More distinctly, we present a clear and conclusive evidence of (2 × 2) reconstruction of the Fe surface due to the atomic rearrangement by IBE. Furthermore, 57Fe isotope sensitive nuclear resonance scattering measurement provides insight into the depth-resolved magnetic information due to the modified surface topography. We also demonstrate that thermal annealing can reversibly tune the surface reconstruction and induced UMA. The feasibility of the IBE technique by adequately selecting IBE parameters for surface structure modification has been highlighted apart from conventional tailoring of the morphology for the tuning of UMA and introduces a new dimension to our understanding of self-assembled surface morphology evolution by IBE. [ABSTRACT FROM AUTHOR]

The escape dynamics of sticky particles from textured surfaces is poorly understood despite importance to various scientific and technological domains. In this work, we address this challenge by investigating the escape time of adsorbates from prevalent surface topographies, including holes/pits, pillars, and grooves. Analytical expressions for the probability density function and the mean of the escape time are derived. A particularly interesting scenario is that of very deep and narrow confining spaces within the surface. In this case, the joint effect of the entrapment and stickiness prolongs the escape time, resulting in an effective desorption rate that is dramatically lower than that of the untextured surface. This rate is shown to abide a universal scaling law, which couples the equilibrium constants of adsorption with the relevant confining length scales. While our results are analytical and exact, we also present an approximation for deep and narrow cavities based on an effective description of one-dimensional diffusion that is punctuated by motionless adsorption events. This simple and physically motivated approximation provides high-accuracy predictions within its range of validity and works relatively well even for cavities of intermediate depth. All theoretical results are corroborated with extensive Monte Carlo simulations. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of simulated gastric acid solution (SGAS) and resin cement composition on the shear bond strength (SBS) of zirconia-based materials with different levels of translucency to composite resin. Materials and Methods: A total of 40 medium-opacity (MO; 3Y-TZP) and 40 medium-translucency (MT; 4Y-PSZ) zirconia slabs were distributed into four groups according to the composition of the resin luting system (MDP free or with MDP [primer + Panavia V5]) and storage method (distilled water or SGAS [5% hydrochloric acid]). Composite resin cylinders were cemented on the zirconia surface and stored for 91 hours. SBS, failure mode, and surface characterization analyses via scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were performed. SBS data were analyzed using three-way ANOVA and Tukey tests, and failure mode was assessed using one-way ANOVA (P < .05). Results: Storage media (P = .180), resin cement (P = .110), zirconia (P = .404), and their interactions did not affect SBS values. Bond strength ranged from 21.41 to 26.11 MPa. SEM images showed that SGAS modified the surface topography of zirconia and resin cement. The presence of chlorine and silicon (wt%) were higher after SGAS storage than after water storage in both cements used, while barium was higher only for the MDP cement. There was a prevalence of mixed failures for most of the groups. Conclusions: The SBS between both types of zirconia and resin cement was not affected by SGAS, although changes in zirconia topography were observed after SGAS exposure. The presence of MDP in the cement layer had no effect on the SBS challenged by SGAS. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the influence of aging on the fracture load (Lf) and reliability of glass- ceramics a;er different etching protocols. Materials and Methods: Specimens were fabricated and divided according to the etching Ame (10% hydrofluoric acid [HF] for 20 seconds, 40 seconds, and 60 seconds). Etched surfaces were examined under microscopy. The ceramics were resin-cemented to a denAn analog material. Samples were split into two groups (n = 20 each) and tested a;er 24 hours (I) or stored in 37°C water for 1 year (A). A compressive load (0.1 mm/minute) was applied to the samples unAl failure was detected by acoustic emission. The influence of aging on the Lf was tested by two-way ANOVA and Tukey tests (α = .05). The characterisAc fracture load (L0) and Weibull modulus (m) values were calculated. Results: Lithium silicate (LS) etching for 20 seconds resulted in the highest immediate Lf, which was significantly decreased a;er aging (P ≤ .05). Water storage had no effect on the Lf of glass- ceramic etched for 40 and 60 seconds (P > .05). For lithium disilicate (LD), the etching Ame had no significant effect on the immediate or aged Lf (P > .05). The Lf was significantly reduced a;er aging (A) for LD (P ≤ .05). Radial cracks were the predominant failure mode. Surface topography was more regular a;er lower etching Ames for LD and a;er higher Ames for LS. Conclusions: After 1 year of water-assisted aging, the evaluated etching Ames had no influence on the load-bearing capacity and structural reliability of resin-bonded glass- ceramics. [ABSTRACT FROM AUTHOR]

In the machining of high-strength materials, shear localization in serrated chip formation leads to time-varying thermo-mechanical loads exerted by the cutting tool on the machined surface. This results in periodic changes to surface integrity. This article explains the formation mechanism of machined surface microfeatures and residual stress fluctuations associated with serrated chip formation, based on a finite element model of machining Waspaloy using the coupled Eulerian-Lagrangian method. The model is validated by comparing the simulation results with experimentally measured chip morphologies and machined surface profiles. During machining with a constant chip thickness, the machined surface exhibits a uniformly distributed residual stress pattern along the cutting velocity direction. However, increased cutting velocity and serrated chip formation cause periodic shear bands, leading to time-varying location of the stagnation point on the cutting tool. This results in variations in the workpiece material volume and the thermo-mechanical loads in the plowing region. After machining, the periodical variation in the elastic recovery of the plowed material at the bottom of the cutting tool creates waveforms on the finished surface, accompanied by fluctuations in residual stress at the same frequency as chip serration. The simulations quantitatively determine the normal/shear contact force at the tool-workpiece interfaces to reveal the effect of the time-varying stagnation point location on surface topographies and residual stress distributions. [ABSTRACT FROM AUTHOR]

Electrolyte additive engineering is a feasible protocol in improving Zn anode stability. Typical additive designs center on the regulation of Zn deposition; nevertheless, versatile additives are urgently requested to comprehensively manage the surface landscape, interface physicochemistry, and by‐product elimination. Here, a straightforward strategy is presented to meet such needs employing an environmentally‐friendly chelator, hydroxyethyl‐ethylenediaminetriacetate acid (HEDTA), as an additive for ZnSO4 electrolyte. Throughout theoretical computations and experimental investigations, it is demonstrated that protons released from the gradual ionization of HEDTA during rest periods aid in the mild engraving of the Zn surface. Both the amino and carboxyl groups of HEDTA⁻ can be protonated, which effectively buffers the interfacial pH value in the entire battery lifespan and eliminates the formation of by‐products. The HEDTA− anions can also adsorb onto the Zn surface, helping facilitate Zn2⁺ mass transfer and accelerate the desolvation process. Benefiting from the synchronous modulation of surface topography and interfacial physicochemistry, the assembled half cells affording HEDTA additive maintain a durable operation of up to 8821 cycles at 5.0 mA cm−2/1.0 mAh cm−2. Additionally, symmetric cells manifest stable cycling for over 4600 h at 0.5 mA cm−2/0.25 mAh cm−2. [ABSTRACT FROM AUTHOR]

This paper proposes a strategy to overcome the problem of poor surface quality when grinding difficult-to-cut materials at a small scale, by creating a small-scale grinding tool with a regular array structure (SSGT-RAS) through the method of combining low-speed wire electrical discharge turning (LS-WEDT) machine technology and electroplating process. A numerical model is established to describe the surface topography of SSGT-RAS grinding of titanium alloy Ti-6Al-4V, taking into account the shape, size and distribution of the abrasive grains, the plastic material removal mechanism and the machining parameters. The study comparatively analyses the surface morphology characteristics and surface generation mechanism of SSGT-RAS and ordinary cylindrical grinding tool (OCGT) when grinding titanium alloy Ti-6Al-4V with different helical groove depths through side dry grinding experiments. The experimental results show that SSGT-RAS improves the surface quality of the workpiece compared to OCGT, and surface roughness Ra can be reduced by up to 25.20 ~ 27.81% and 21.49 ~ 35.44% at most by changing the feeding velocity and cutting depth, respectively. In addition, increasing helical groove depth further improves the surface quality. A comparative analysis of the simulation and experimental results shows that the prediction error of the surface roughness Ra is within 15.92%. This research expands the preparation process of surface-structured grinding tool at small scale, which has significant theoretical and engineering applications. [ABSTRACT FROM AUTHOR]

The process of high-speed and high-precision machining is highly dependent on the wear process of the tool, so it is necessary to obtain the accurate identification of the wear state of the tool and the timely prediction of the degradation trend through effective detection methods. However, the influencing factors of the real cutting process are complex and variable. The milling process is a complex spatial deformation process, accompanied by very high cutting accuracy requirements, and it is hard to use VB value, the currently popular singular linear indicator of wear state evaluation, to describe the current wear state of end mills precisely and difficult to make a valid decision proof for subsequent dynamic degradation trends. For these issues, a three-dimensional wear region reconstruction and calculation method for end milling cutters based on bi-sensor monitoring information is proposed in this paper, which can be accurately used to estimate the volume of current wear areas and give more reasonable predictions of future wear trends. Firstly, an in situ wear detection device with a bi-sensor based on an industrial camera and line laser scanner is designed, which can obtain the wear shape and depth information synchronously with high precision. Secondly, aiming at the problem of missing wear information due to uneven furring wear on the rear tool face of the end milling tool, this paper proposes a combined threshold segmentation method to extract the complete tool wear region, which improves the calculation precision of the wear region. Thirdly, the SFS algorithm, which integrates high-precision scale information from line laser data, is utilized to reconstruct the rear tool surface topography. This reconstruction allows for accurate estimation of the wear volume. Finally, the experiment results have shown that the wear volume can reflect the wear state of the tool more quickly and comprehensively compared with the traditional tool wear width standard, and it can provide early warning before the tool enters severe wear condition. [ABSTRACT FROM AUTHOR]

In tapping mode atomic force microscopy (TM‐AFM), the phase image can reveal more about the physicochemical properties of the sample surface than the topography image, making it widely utilized in fields such as materials science and life sciences. However, obtaining high phase contrast in phase images during experiments is challenging, thus studying the phase imaging theory of TM‐AFM and optimizing phase contrast methods hold significant importance. This paper derives a theoretical expression for phase contrast based on phase theory, discovering that phase contrast is directly related to the frequency ratio and background dissipation quality factor. Through theoretical, experimental, and simulation approaches, optimization methods for phase contrast were proposed from the perspectives of frequency ratio and background dissipation quality factor as follows: (1) By fitting experimental results with the theoretical expression for phase contrast, the optimal frequency ratio for scanning can be determined, and imaging with this optimal ratio can enhance phase contrast and (2) reducing the width ratio between the free and fixed ends of the probe can decrease background dissipation, increase the proportion of core dissipation in the total energy dissipation of the probe, and thereby improve phase imaging contrast. These findings are significant in guiding TM‐AFM phase scanning experiments and optimizing phase imaging contrast. [ABSTRACT FROM AUTHOR]

Capacitive touch screens (CTS's) are essential components in most of today's digital devices. However, for the visually impaired (VI) users due to the uneven topography of the tactile surface, CTS's are more challenging to implement and thus this field remains largely underdeveloped. Considering the limited space around the microactuators driving the typical Braille dots for a tactile screen with ten dots‐per‐inch (dpi) resolution, the materials used for CTS should be flexible and durable with high mechanical strength. In this work, a flexible CTS based on polyimide (PI) and silver nanowires (AgNWs) as electrodes with a total thickness of 210 µm is developed. The dimensions of the AgNWs are on average 7.9 ± 2.4 µm in length and 85 ± 24 nm in width. The AgNWs electrodes showed low resistance and good adhesion to the PI substrate. A gesture recognition application is collected from the capacitive data to classify different gestures (including single‐ and double‐click, swipe‐left and ‐right, scroll‐up and ‐down as well as zoom‐in and ‐out) with two different approaches; machine learning and deep learning are implemented. The best performance is obtained using the YOLO model with a high validation accuracy of 97.76%. Finally, a software application is developed with the proposed hand gestures in real‐time to foster interaction of VI users with the tactile display allowing them to navigate a Windows file system and interact with the documents via hand gestures in a similar manner as sighted users on a conventional touch display will be able to do. This work paves the way to utilize CTS for the tactile displays in the market developed for VI users. [ABSTRACT FROM AUTHOR]

ABSTRACT In numerical studies of grease lubrication, thermal effect is often neglected and surface plastic deformation is almost not considered. This paper has developed a deterministic thermal plasto‐elastohydrodynamic lubrication (PEHL) model for grease‐lubricated rolling bearing. The influence of tangent modulus, rheological index and texture orientation on lubrication characteristics and temperature rise is analysed. The results show that increasing the rheological index of grease and decreasing the wavelength factor are obviously positive for improving lubrication behaviour. Since surface plastic deformation in the EHL state is at nanoscale, film thickness, friction coefficient and temperature rise of solid surfaces decline slightly with the decrease of tangent modulus. [ABSTRACT FROM AUTHOR]

The Cu-2 wt% Sb alloy was prepared and exposed to various heat treatments at temperatures ranging from 573 to 973 K to get distinct grain diameters. Different samples of various grain diameters were individually sputtered in an argon glow discharge for various times (0.5, 1, 2 h) using a DC magnetron sputtering device. The surface topography and microstructural features of a Cu-2 wt% Sb alloy were examined utilizing an optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The C u 3 S b IMC phase was found to segregate at the grain boundaries. Results showed that the topographical features of sputtered samples (grain boundaries, tiny cones, cratered cones, and etch pits) were mainly affected by grain size and sputtering time. Moreover, the mechanical properties of a Cu-2 wt% Sb alloy were examined. The parameters of the stress–strain curves (Young modulus Y, 0.2% offset stress σy0.2, fracture stress σf, parabolic work-hardening coefficient χ p , and ductility ε f \% ) were measured under different testing conditions. Generally, these stress parameters decrease as the grain diameter increases. These parameters, with the exception of ε f \% , increase as the strain rate increases, while ε f \% decreases as the strain rate increases. Additionally, selective samples of the present alloy were irradiated using γ-radiation with different doses 0.5, 1, 1.5, and 2 MGy. The Vickers microhardness of annealed and irradiated samples lowered as the grain size augmented, while it increased as the irradiation dose increased. Based on the obtained activation energy Q value of 20.65 kJ/mol., it is indicated that the predominant deformation mechanism in the Cu-2 wt% Sb alloy is the motion of dislocation through the Cu-matrix. [ABSTRACT FROM AUTHOR]

The corrosion behavior of the TiTaNbZrAg alloys with different amounts of tantalum (0%, 10% and 20%) and with distinct surface topography (smooth and rough) was investigated in phosphate buffer solution (PBS) for long-time immersion (1000 h). By this approach, we expect to bring about new insights into the influence of both the amount of Ta in the alloy composition and the surface topography on the corrosion behavior of the Ti-based alloys. The corrosion resistance was studied by Open Circuit Potential (OCP), Potentiodynamic Polarization (PP), and Electrochemical Impedance Spectroscopy (EIS). From the potentiodynamic investigations, it was observed that all types of samples showed good corrosion resistance (i.e., Rcorr < 10 µm y−1) and may be used successfully for medical applications. However, the samples with smooth surfaces and with a certain amount of Ta (10% and 20%) exhibit the best corrosion performance (Rcorr < 1 µm y−1). As regards the samples with rough surfaces, the results evidenced that they showed lower corrosion resistance (1 < Rcorr < 3 µm y−1), suggesting that the Ta presence does not necessarily hinder the corrosion processes. Actually, the synergetic effect of both the presence of Ta and surface roughness plays an important role in corrosion resistance. [ABSTRACT FROM AUTHOR]

This paper presents the results of studies aimed at assessing the impact of the molding process on the variability of surface irregularities of casting models. This research was conducted using a selected multiscale method, i.e., wavelet transformation, in both discrete and continuous perspective. The test samples were made both based on traditional methods of manufacturing casting models, i.e., machining of aluminum and wood, as well as using three additive technologies. The impact of the forming process on the variability of the topography of the produced models was evaluated. This research comprehensively relates to the assessment of the applicability of additive technologies, which are increasingly used in various industrial areas, as well as the impact of the process on surface topography in relation to scale. The statistical assessment based on the ANOVA analysis demonstrated that it is possible to distinguish between the surfaces before and after a specific number of forming cycles. Studies have shown that the impact of the forming process is relatively small, mainly affecting the long-term irregularity components, and there are no functional dependencies in terms of the impact of the forming process on the variation in surface topography in relation to the manufacturing method or its parameters. [ABSTRACT FROM AUTHOR]

Wetting and drying cycles (WDCs) have a significant impact on the shear behavior of discontinuities with different joint wall materials (DDJMs). This influence is crucial for the reasonable evaluation of the long-term stability of soft and hard interbedded rock slopes under water level fluctuations. As the surface topographies of natural discontinuities collected from the field vary, conducting comparative experiments on natural discontinuity specimens with identical surface topographies is challenging. To solve this problem, a 3D surface topography reconstruction technique was employed to obtain DDJM specimens with three types of surface topographies collected from a typical sliding-prone stratum in the Three Gorges Reservoir area, China. A series of experiments, including computed tomography scanning, 3D laser scanning, and direct shear tests, were conducted to investigate the influence of WDCs on the micro- and macroproperties of joint walls, surface topographies, and shear behavior of DDJMs. The experimental results showed that repeated WDC treatments caused the degradation of the microstructures and macroscopic physical properties of the studied joint walls, and the more severely weakened joint wall played a predominant role in reducing the shear strength of DDJMs. The influence of WDCs on the surface topographies of DDJMs was negligible in this study; changes in the shear behavior of DDJMs were closely associated with the weakening of joint walls induced by WDCs; and the impact degree of joint wall weakening on the deterioration of the shear behavior of DDJMs was interactively influenced by and positively correlated with both the joint roughness coefficient and normal stress. These results will contribute to a better understanding of the evolution of the stability of soft and hard interbedded rock slopes induced by water level fluctuations in the Three Gorges Reservoir area and other reservoir regions. [ABSTRACT FROM AUTHOR]

Purpose: At present, research on the preparation of corrosion inhibitors using modified pyrimidine derivatives is still blank. The purpose of this study is to synthesize a new cationic mercaptopyrimidine derivative quaternary ammonium salt, known as DTEBTAC, that can be used as a corrosion inhibitor to slow down the metal corrosion problems encountered in oil and gas extraction processes. Design/methodology/approach: A new corrosion inhibitor was synthesized by the reaction of anti-Markovnikov addition and nucleophilic substitution. The weight loss method was used to study the corrosion inhibition characteristics of synthetic corrosion inhibitors. Electrochemical and surface topography analyses were used to determine the type of inhibitor and the adsorption state formed on the surface of N80 steel. Molecular dynamics simulations and quantum chemistry calculations were used to investigate the synthetic corrosion inhibitor's molecular structure and corrosion inhibition mechanisms. Findings: The results of the weight loss method show that when the dosage of DTEBTAC is 1%, the corrosion rate of N80 steel in hydrochloric acid solution at 90? is 3.3325 g m-2 h-1. Electrochemical and surface morphology analysis show that DTEBTAC can form a protective layer on the surface of N80 steel, and is a hybrid corrosion inhibitor that can inhibit the main anode. Quantum chemical parameter calculation shows that DTEBTAC has a better corrosion inhibition effect than DTP. The molecular dynamics simulation results show that DTEBTAC has stronger binding energy than DTP, and forms a network packing structure through hydrogen bonding, and the adsorption stability is enhanced. Originality/value: A novel cationic mercaptopyrimidine derivative quaternium-ammonium salt corrosion inhibitor was designed and provided. Compared with the prior art, the preparation method of the synthesized mercaptopyrimidine derivative quaternary ammonium salt corrosion inhibitor is simple, and the presence of nitrogen-positive ions, sulfur atoms and nitrogen-rich atoms has an obvious corrosion inhibition effect, which can be used to inhibit metal corrosion during oil and gas field exploitation. It not only expands the application field of new materials but also provides a new idea for the research and development of new corrosion inhibitors. [ABSTRACT FROM AUTHOR]

Gear tooth spalling is a typical tooth surface defects in gear transmission. The accurate calculation of the time-varying mesh stiffness of the gear pair with spalling defect under mixed elastohydrodynamic lubrication (EHL) plays an important role in tooth damage prediction and fault feature analysis. In this work, an improved time-varying mesh stiffness (TVMS) model of spalling faulty gear in mixed EHL line contact considering the coupled effect of rough surface topography is established. The proposed model considers the combined effect of spalling defect, surface roughness topography, and lubrication on the contact characteristics of the meshing interface to obtain a revised contact stiffness, which is further used to determine the comprehensive TVMS. The cylindrical contact coefficient for curved meshing interface with spalling fault is derived and incorporated into the statistical micro-contact Greenwood and Williamson model (GW model) to obtain the asperity contact stiffness. The revised contact stiffness at the rough faulty gear interface is obtained from the parallel action of the asperity contact stiffness and oil film stiffness under load-sharing concept. The dynamic responses of the gear system are analyzed using the established mesh stiffness model through the six degrees of freedom translational-torsional dynamic model, in which the dynamic meshing force is calculated iteratively using the transit surface topography and geometrical parameters along the line of contact instead of a quasi-static meshing force. Effects of multi-parameters as surface roughness, spalling fault size, and lubricant on the mesh characteristics and dynamic responses of the gear system are further investigated and discussed. [ABSTRACT FROM AUTHOR]

GH4169 superalloy is an outstanding material used in aerospace, and precision grinding is widely applied to machine GH4169 superalloy, where the grinding force plays essential role on the ground surface quality and the achieved surface topography. In this paper, the material removal mechanism under different machining parameters is analyzed in cylindrical grinding of GH4169 superalloy. The interaction process between abrasive grain and workpiece material is investigated to establish the simulation model of material removed based on the kinematics. The random wheel topography is constructed statistically using the probability density function that characterizes the distribution of the grains. The simulated grinding force and surface topography are in good agreement with the experimental results. Specifically, the errors of the tangential and normal grinding force are 5.33% and 6.33% and the errors of the roughness Sa and Sz are 5.51% and 7.40%, respectively. Based on the simulation model and calculation results, the machining parameters are optimized for cylindrical grinding of GH4169 (vs = 45 m/s, f = 150 mm/min, ap = 3 μm, vw = 0.262 m/s) to improve the achieved surface quality. [ABSTRACT FROM AUTHOR]

In this paper, the effects of ultrasonic vibration and powder mixed on Electrical Discharge Machining (EDM) are investigated. Based on the heat transfer theory, an ultrasonic powder mixed EDM (US-PMEDM) heat transfer model combining ultrasonic vibration and powder mixed characteristics is established, and the heat transfer model carries out a transient thermodynamic simulation for the process of removing the material during the EDM process, and through the experimental and simulation analysis of four kinds of EDM, powder mixed EDM (PMEDM), ultrasonic (UEDM), and US-PMEDM, the accuracy of the simulation is verified. The accuracy of the simulation was verified by observing the surface morphology after machining. The material removal process was analyzed under different machining methods and different concentrations of powder mixed particles. Under the processing conditions of fixed processing current of 2A, ultrasonic amplitude of 5 µm, and powder concentration of 2g/L, the material removal rate (MRR) of the PMEDM method was increased by about 26.3% and the surface roughness (SR) was reduced by 7.78% compared with that of the EDM method, and the material removal rate of the US-PMEDM method was increased by about 49.4% and the surface roughness was increased by 4.05% compared with that of the EDM method. The surface quality can be improved by adding powder mixing, and the surface quality of powder mixing is better than that of ultrasonic vibration. [ABSTRACT FROM AUTHOR]

The Hirtisation® process is an electro-chemical process, wherein the electrolyte can easily access both external and internal surfaces. The process shows promising results in both support structure removal and reduction of surface roughness, and has the potential to solve the productivity and quality trade-off in powder bed fusion – laser beam (PBF-LB) processing. In this study, the role of the microstructure and surface topography on the capability of the Hirtisation® process to lower the PBF-LB produced surface roughness, has been investigated. A detailed microstructure analysis by SEM was used to determine the effect of the Hirtisation® process on removal of sintered powder, the effects on melt pool boundaries and grain boundaries, and thus the final surface quality. The Hirtisation® process significantly reduced surface roughness thanks to the complete removal of sintering powder from the as-built surface. Additionally, preferential material removal was detected along melt pool boundaries, leading to creation of notches of up to 10 µm in depth. [ABSTRACT FROM AUTHOR]

Solid lubricants are added to polymers to upgrade their tribological properties, especially in cases where adhesive and abrasive friction are valid. However, there are not enough studies on the effects of solid lubricants on particle erosion. This study investigated the effects on solid particle erosion behavior of three different well known solid lubricants (molybdenum disulfide, polytetrafluoroethylene, and graphite). These solid lubricants were added at three different ratios (5, 10, and 15 wt.%) to the two different type (rigid and toughened) epoxy resins. Garnet abrasive particles (180–400 μm) were blasted to the sample surface under 1.5 bar for 15 s to conduct solid particle erosion tests. The erosive wear mechanisms of neat and solid lubricant‐reinforced epoxy resins were investigated in relation to the epoxy type, solid lubricant type, and solid lubricant reinforcement ratio. Statistical analysis was performed according to response surface methodology to support the experimental results, and ANOVA tables were obtained. The wear and deformations that occurred on the surface after solid particle erosion were examined using a noncontact optical profilometer system and scanning electron microscopy, and a significant relationship was detected between the deformation on the surface and particle erosion. Analysis results showed that the factor causing the greatest erosion rate change was the epoxy resin type. Finally, it has been observed that all solid lubricants reduce the erosive wear resistance, and this resistance decreases as the weight ratio increases. Highlights: Investigations were conducted into the erosion behavior of two types of epoxy resins: rigid and toughened. The toughened epoxy resin exhibited greater resistance to erosion. Although it has the same type of content, on average, rigid epoxy worn 2–4 times more than toughened epoxy.The effect of adding polytetrafluoroethylene tended to increase the erosion rate of both rigid and toughened epoxy resin less than that of other solid lubricants.Graphite particles increased the erosion rate of toughened epoxy by 1.5–3 times and that of rigid epoxy by 2–3 times, depending on the value of the reinforcement ratio.MoS2 increased the erosion rate of toughened epoxy by 1.5–3 times and that of rigid epoxy by 2–3 times.Using a noncontact optical profilometer (for investigating surface topography), it was proven that there is a significant relationship between the erosion rate and roughness characteristics. Wear mechanisms were identified by SEM analysis. [ABSTRACT FROM AUTHOR]

Surface roughness significantly impacts the service life of materials, particularly in relation to fatigue and wear behavior. This study investigates the effects of surface mechanical attrition treatment (SMAT) on the wear performance and surface topography of AA7075‐T6 aluminum alloy. Experimental investigations are conducted using a specially designed vibration table to apply SMAT at low speeds, varying shot amount, and shot diameter. Surface roughness is measured using a 3D optical profilometer, and wear performance is evaluated through friction coefficient, wear rate, and microstructural analysis via scanning electron microscope. The results highlight several key findings. First, SMAT demonstrates the capability to yield smoother surfaces compared to equivalent processes, enhancing performance and applicability in engineering contexts. Second, SMATed samples exhibit increased surface roughness compared to untreated samples, underscoring the influence of SMAT on surface topography and its potential implications for wear resistance and frictional behavior. The comparative analysis shows that SMAT treatment increases surface roughness from 0.14 μm to a maximum of 0.24 μm. Finally, a notable reduction in friction coefficient, up to 22%, is observed in SMATed AA7075‐T6 samples, indicating the effectiveness of SMAT in improving tribological properties and enhancing component longevity subjected to frictional forces. [ABSTRACT FROM AUTHOR]

Background: Adolescent idiopathic scoliosis (AIS) is a pathological condition characterized by vertebral curvature and associated trunk deformities in adolescents. The clinical efficacy of conservative treatment in alleviating spinal curvature of AIS remains a topic of ongoing debate. The objective of this study was to investigate the impact of combined physiotherapeutic scoliosis-specific exercises (PSSE) and manual therapy (MT) on trunk deformity, spinal function, mobility, and mental health in patients with AIS. Methods: Thirty-one participants who were diagnosed with AIS whose Cobb angle was between 10–45°were enrolled in the study. Participants in the intervention group received 50 min of PSSE combined with 10 min of MT, while the control group performed 50 min of PSSE as their home exercise program. Both treatments were implemented three times a week for four weeks. Cobb angle, spinal mobility, trunk morphology (vertebral rotation angle, apical deviation, pelvic obliquity distance and angle), movement capability, and quality of life (QOL) were assessed at baseline and post intervention. The treatment effects between the intervention and control groups were analyzed using a two-way repeated measures ANOVA. Results: Following a 4-week treatment period, Cobb angle was significantly reduced from 21.58° to 18.58° in intervention group and increased from 18.00° at baseline and 19.14° post intervention in the control group. Significant improvements were also observed in spinal mobility, movement capability, quality of life, and some of the trunk morphology indices in the intervention group compared to baseline (p < 0.05). Improvements were significantly higher in the intervention group than the control group. Conclusion: Combining PSSE and MT shows potential benefits in alleviating AIS symptoms and improving QOL. Further studies to substantiate these findings are warranted. Trial registration: The trial was retrospectively registered in the Chinese Clinical Trial Registry () with the registration number: ChiCTR2300071357, (Date: 12/05/2023). [ABSTRACT FROM AUTHOR]

The complexity and randomness of surface roughness make the origin of friction always puzzling. Is there a potential correlation mechanism between the evolution of friction force and surface topography, and is it possible to estimate the friction coefficient from the topography evolution? Here, we explore the evolution of surface topography in metallic materials during friction by defining the characteristic orientation of the surface and analyzing its changes over time, which closely mirrors the behavior of friction forces. Then, we propose a simple relationship that relates the characteristic orientation and friction force via the friction coefficient. Therefore, the friction coefficient can be evaluated based on topography evolution without relying on any theoretical modeling assumptions. These results reveal the mechanism between complex surface topography and friction force through a simple formula and provide a method to estimate the friction coefficient. This method has promising applications when the friction coefficient is difficult to measure, such as in large-scale landslides and geologic faults. [ABSTRACT FROM AUTHOR]

Controlling the propagation of light in the form of surface modes on miniaturized platforms is crucial for multiple applications. For dielectric multilayers that sustain Bloch surface waves at their interface to an isotropic dielectric medium, a conventional approach to manipulate them exploits shallow surface topographies fabricated on top of the truncated stack. However, such structures typically exhibit low index contrasts, making it challenging to confine, steer, and guide the Bloch surface waves. Here, we theoretically and experimentally demonstrate a device for a Bloch surface wave platform that resonantly couples light from a cavity to a straight waveguide. The structure is designed using topology optimization in a 2D geometry under the effective index approximation. In particular, the cavity–waveguide coupling efficiency of the radiation emitted by an individual source in the cavity center is optimized. The cavity is experimentally found to exhibit a narrow resonant peak that can be tuned by scaling the structure. The waveguide is shown to guide only light that resonates in the cavity. Fully three-dimensional simulations of the entire device validate the experimental observations. [ABSTRACT FROM AUTHOR]

Physical insult to the central nervous system (CNS) such as during electrode insertion leads to reactive astrogliosis which in turn contributes to glial scarring (GS). To date, reducing GS in these settings has focused on pharmacological agents and variations in electrode material composition or implantation procedures, and the role of electrode surface topography has remained unexplored. Since proteoglycans, a major component of GS tissue, possesses very well‐defined (nano) topography, a role for stochastic nanoroughness in glial scar formation is theorized. Using an in vitro system, we provide proof of concept that on substrates possessing stochastic nanoroughness corresponding to that of healthy astrocytes, glial scar formation is significantly inhibited, and more importantly, can be even reversed, and it involves signaling via the stretch‐activated cation channel Piezo‐1. In vivo studies reveal an absence of astrocytes aggregation along the electrode track of chronically implanted electrodes modified with stochastic surface nanoroughness, compared to non‐modified electrodes, while signal detection within the superior colliculus remains unaffected. These findings shedlight on the crucial role of stochastic biophysical cues in modulating GS formation; and offer a promising non‐chemical approach for engineering neural biomaterials interface for the CNS. [ABSTRACT FROM AUTHOR]

The rise of infections associated with indwelling medical devices is a growing concern, often complicated by biofilm formation leading to persistent infections. This study investigates a novel approach to prevent Candida albicans attachment on the surface by altering surface topography. The research focuses on two distinct surface topographies: symmetry (squares) and non-symmetry (lines), created through a direct laser photolithography process on a Cyclic olefin copolymer (COC) surface. The wettability of these patterned surfaces was then examined immediately after fabrication and plasma treatment to mimic the sterilization process of indwelling devices through UV plasma. The results reveal directional wettability in the line pattern and size-dependent wettability in both square and line patterns. Candida albicans were cultured on these surfaces to assess the efficacy of the topography in preventing biofilm formation. The study demonstrates that symmetry and non-symmetry pattern topography inhibit biofilm formation, providing a promising strategy for mitigating Candida-associated infections on medical devices. The research sheds light on the potential of surface modification techniques to enhance the biocompatibility of medical devices and reduce the risk of biofilm-related infections. [ABSTRACT FROM AUTHOR]

Bone formation on implant surfaces occurs via distance and contact osteogenesis, with osseointegration influenced by the implant's surface topography and coating. However, the traditional mechanisms of osseointegration around metal implant surfaces may not fully encompass the ultimate outcomes of using medical-grade polycaprolactone β-tricalcium phosphate calcium phosphate coated (mPCL-TCP-CaP) scaffolds for the reconstruction of large bone defects. Using histology, immunohistochemical (IHC) and scanning electron microscopy (SEM) analyses our studies on large bone defects using mPCL-TCP-CaP scaffolds show osteogenic cells forming a fibrous connective matrix around these scaffolds. Despite extensive research, the in vivo mechanisms of osseointegration of CaP-coated mPCL-TCP-CaP scaffolds remain unclear. This study investigates the structural details and spatial organization of the mPCL-TCP-CaP scaffold's interface, providing insights into the histodynamic processes involved in their osseointegration with CaP coatings. [ABSTRACT FROM AUTHOR]

This study presents an experimental investigation of the mechanical behaviour of recycled rubber pads coated with graphene nanoplatelets. The investigation is part of an effort to develop a novel rubber-based composite that aims to reroute rubber from end-of-life tyres from illegal landfills and incineration back into the market in the form of a novel composite for vibration isolation. Graphene nanoplatelets were deposited on rubber pads via ultrasonic spray coating. The pads were made of a combination of recycled rubber (from tyres) and virgin rubber. A comprehensive analysis of the structural and chemical properties of the graphene coating, ensuring its integrity on the rubber substrate, was performed by combining surface topography, Raman and Fourier-transform infrared (FTIR) spectroscopy. Stacked coated pads were cured and tested dynamically in compression and shear under cyclic loading. Results showed promising improvements in the mechanical properties, in particular, in compressive stiffness and damping of the coated specimens with respect to their uncoated counterparts, laying the foundation for using graphene-enhanced recycled rubber as a novel composite. This article is part of the theme issue 'Celebrating the 15th anniversary of the Royal Society Newton International Fellowship'. [ABSTRACT FROM AUTHOR]

In this study, the impact of three different principles of surface activation techniques for polyamide fibers on the formation of conductive percolation during the subsequent electroless copper deposition process was investigated. The techniques used are (1) polyamide complexation using a solution mixture of calcium chloride, ethanol and water, (2) atmospheric plasma surface treatment and (3) grafting of 2‐hydroxyethylmethacrylate by radical induced polymerization. As a result, the percolation threshold was shifted to lower copper contents. The copper content required to form conductive structures was reduced ranged between 59% and 89%, depending on the activation techniques. Furthermore, the deposition time was reduced by 37%–57%, resulting in a faster build‐up of the percolation on the fabric. Changes in wetting behavior and substrate surface topography were identified to be the main reasons for these observations. While all applied surface activation techniques led to higher copper contents compared to unmodified reference, the atmospheric plasma modification led to the highest copper contents during the deposition process and a more uniform appearance of the metallised layer. Highlights: Three different fiber surface activation methods are evaluated.Fiber surface activation increases wetting and polymer‐metal adhesion.Activated polymer surface leads to faster copper deposition and percolation.Atmospheric plasma modification is the most efficient technique. [ABSTRACT FROM AUTHOR]

Measurements of areal (3D) surface texture using optical methods are very popular because of the short measurement time compared to the stylus tip technique. However, they are very sensitive to measurement errors. In some cases, optical measurements are not recommended. The stylus measurement method is well known and can be the reference technique for surface texture measurement. The main disadvantage is the long measuring time. This time can be shortened using higher speeds of measurement. The effect of the speed of the measurement of stylus profilometer on changes in surface texture parameters was studied. Fifty surface topographies were measured using the stylus profilometer at speeds 0.5, 1, 2, 3, 4, and 5 mm/s in the same places. Surfaces after lapping, polishing, grinding, milling, laser texturing, and two-process random surfaces were measured and analyzed. Changes in parameters caused by the increase in the traverse speed depend on the characteristics and parameters of the surfaces. The random surfaces changed more than the deterministic ones. The increase in the traverse speed from 0.5 to 1 mm/s caused small changes in the parameters. [ABSTRACT FROM AUTHOR]

The topological characteristics of the down-skin surfaces for as-built components by laser powder bed fusion (LPBF) are particularly representative, while the study on the improvement of the surface quality of these surfaces remains largely unexplored. Herein, the laser polishing of LPBF-built components with different inclination angles was systematically investigated with an emphasis on the down-skin surfaces. Our result shows that the topography of the top surface is independent of the inclination angle, and the surface topography of the down-skin surface is dominated by additional angle-dependent surface characteristics. It also indicates that the surface roughness can be reduced sharply when increasing the laser power from 40 W to 60 W, and the reduction slows down when further increasing the laser power while decreasing the scanning speed leads to a progressive improvement of the surface morphology. Moreover, a second-order regression model was established to evaluate the influence of the initial surface morphology and polishing parameters on the polished surface roughness and to achieve surface roughness optimization. Therefore, our established methodology can be readily applied to surface morphology manipulation and process optimization for laser polishing of widely used metals and alloys fabricated by the additive manufacturing process. [ABSTRACT FROM AUTHOR]

ABSTRACT This work introduces a damage index (DI) that combines the effective plastic strain and surface roughness changes to predict the future propagation path of a microstructure‐sensitive crack (MSC) in a polycrystalline nickel fatigue sample. The surface topography of a fatigue sample was measured at short fatigue intervals, from which both the effective plastic strain and surface roughness changes were calculated using digital image correlation (DIC). Three DIs based on the effective plastic strain, surface roughness changes, and their combinations were studied using two criteria, that is, the highest intensity and the confidence threshold. Comparing the crack path predicted by these DIs with the actual crack path acquired at later fatigue cycles, we demonstrated that the combined DI is more accurate and has less uncertainty in predicting the future crack path. [ABSTRACT FROM AUTHOR]

Cell adhesion can be significantly influenced by the topography of the substrate surface. However, how the adhesion molecules essentially respond to this topographical stimulus is not fully understood yet. Here, we employ an effective Monte Carlo simulation to systematically investigate a fluctuating membrane interacting with a curved substrate via adhesive proteins. Interestingly, results show that, compared with the flat substrate, curved substrates regulate the membrane adhesion in a bond length dependent manner. The effects of the substrate surface amplitude and wavelength on the number of molecular bonds and adhesion pattern are also extracted from the scaling relationship between the characteristic lateral length of the membrane and the local substrate curvature radius. Furthermore, the local substrate curvature is found to select the bond distribution in terms of the bond length and stiffness. The results suggest that the bond stiffness enhances the clustering of molecular bonds, mainly due to synergistic interactions among these molecular bonds. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to compare the microhardness and surface roughness (Ra) of a resin composite, which was recently introduced to be the first flowable composite with the nano-sized fiber filler, with the particle filled composite resins with different properties, used in Class V cavities. Methods: Totally 100 disc-shaped samples (diameter: 4 mm, height: 2 mm) were prepared and divided into five groups in accordance to the different types of composites (n=20): 1) Flowable composite with nano-fiber filler (Group N: NovaPro Flow, Nanova, USA); 2) Flowable bulk-fill composite [Group Estelite Bulk Fill Flow (EBF): Tokuyama, Japan]; 3) Flowable composite [Group G-aenial Universal Flo (GUF): GC Corp, Japan]; 4) Highly-filled flowable composite [Group G-aenial Universal Injectable (GUI): GC Corp, Japan]; 5) Micro-hybrid composite (Group Z250: Filtek Z250, 3M ESPE, USA). They were polished with aluminum oxide polishing discs. Ra measurements (µm) were made using contact profilometer (MarSurf M 300 C; Mahr GmbH, Germany) (n=10). Vickers microhardness evaluations were made using HMV microhardness tester (Shimadzu, Japan) (n=10). Three dimensional (3D) optic profilometer was used to evaluate the surface topography. One-way ANOVA, Shapiro-Wilk and Tukey tests were used for statistical analysis (p<0.05). Results: At top and bottom surfaces, Group N showed significantly lowest microhardness values while Group Z250 showed significantly highest microhardness values than other groups (p<0.05). Group GUI showed significantly higher microhardness values than group EBF and GUF (p<0.05). Hardness ratio was found lower than 80% in Group N. No significant differences in Ra were found between the groups. 3D optic profilometer revealed that similar scratch appearances were detected in all groups. Conclusion: Incorporation of flowable composite with nanofiber filler may not be advantageous for micro-hardness, hardness ratio and Ra properties. [ABSTRACT FROM AUTHOR]

The horizontal propagation of slab detachment (slab tearing) is known to control lateral migration of the mountain uplift along the collisional belt. However, along‐strike differential collision due to an oblique passive margin geometry can make the topography response more complex. In this study, we employ 3D thermomechanical modeling to distinguish between the lateral migration of the mountain topography driven by slab tearing and oblique continental collision itself. In our models, slab breakoff is triggered by the transition from oceanic to continental subduction, occurring earlier on one side of the passive margin than on the other due to the initial oblique configuration. However, once slab breakoff has begun, it spreads horizontally in the form of tearing at high velocity (∼38–118 cm yr−1), and associated topographic uplift also propagates with the same velocity. In contrast, the along‐strike migration of subsequent continental collision and related topographic uplift propagation is typically much slower (∼2–34 cm yr−1). Similarly, the vertical magnitude of surface uplift caused by slab tearing is higher (up to 10 mm yr−1) than the following collision phase (<4 mm yr−1). The parametric analysis reveals that slab tearing velocity and the associated horizontal propagation of mountain uplift depends on obliquity angle and slab age, whereas the migration of collision‐induced topographic growth is controlled by the convergence velocity and obliquity angle. Finally, we show that presence of microcontinental block detached from the passive margin leads to spatial and temporal transition from horizontal to vertical slab tearing and more intense syn‐collisional mountain building. Plain Language Summary: Continental collision begins after the complete subduction of the oceanic domain, initially located between the colliding continents. As the oceanic slab has negative buoyancy, it detaches from the positively buoyant continental plate shortly after the start of continental collision. Slab detachment leads to a rapid uplift of the surface topography and usually moves sideways, a process known as slab tearing. Slab tearing in turn results in a lateral propagation of the topographic uplift along the continental margin. However, if the colliding plate margins are initially at an angle to each other, an oblique continental collision occurs, which can also lead to along‐strike migration of the mountain uplift. To differentiate between the topography response to slab tearing and oblique continental collision, we have carried out 3D numerical modeling. Our parametric analysis reveals that the rate of slab tearing and the associated horizontal propagation of mountain uplift primarily depend on the angle of collisional obliquity and the age of the subducting oceanic slab, whereas the velocity of plate convergence controls the migration of collision‐induced topographic growth. Our findings also indicate that the surface uplift associated with slab tearing is more pronounced and spreads laterally much faster than during following oblique continental collision. Key Points: We explored numerically in 3D the topography response to horizontal slab tearing during retreating oblique continental collisionHorizontal slab tearing can initiate before collision due to the transition from oceanic to continental subduction below fore‐ and back‐arc domainSurface uplift associated with slab tearing is more pronounced and spreads laterally much faster than in the subsequent collision phase [ABSTRACT FROM AUTHOR]

Background: The utilities of anterior segment optical coherence tomography (AS-OCT) for characterization, differential diagnosis, postoperative monitoring, and evaluation/comparison of surgical techniques in pterygium are described. Through AS-OCT, it is also possible to study the corneal astigmatic effect of pterygium. Our purpose is to study the associations between the anatomical characteristics of pterygium and the corneal topography through AS-OCT. Methods: Fifty eyes with primary pterygium in a tertiary hospital were evaluated before surgery by measuring 10 anatomical variables of pterygium and 13 topographic variables using AS-OCT (Casia 2; Tomey Corp., Nagoya, Japan). Statistical analysis was used to study the association between them. Results: Pterygium classified as flat pattern exhibited lower preoperative values of flat keratometry (K1), real flat keratometry (K1r), average keratometry (AvgK), and real average keratometry (AvgKr) compared to nodular ones. The flat pattern showed greater cylinder (CYL) and real cylinder (CLYr) values. The horizontal corneal invasion proportionally increased CYL and CYLr. Overall, larger anatomical pterygium measurements (limbus thickness (LimbusT), central pterygium thickness (CentreT), head pterygium thickness (HeadT), epithelial thickness at 1 mm (EpitT1mm), stromal thickness at 1 mm (stromT1mm), total thickness at 1 mm (TotalT1mm), total thickness at 2 mm (TotalT2mm), and total thickness at 3 mm (TotalT3mm)) resulted in lower anterior K1, K1r, AvgK, and AvgKr, and posterior K1 and AvgK values. CentreT was greater in astigmatisms against the rule than in oblique ones. Conclusions: This study demonstrates associations between preoperative topography and the NF (nodular or flat) classification of pterygium and its anatomical measurements assessed by AS-OCT. [ABSTRACT FROM AUTHOR]

High velocity oxyfuel coatings have been sprayed on aluminium (Al) alloy composites substrate with varying coating thickness and tested for their wear behavior. The density and micro‐ hardness of the coatings found to increase with increase in coating thickness. The air erosion wear test has been conducted using quartz sand of size up to 75 μm as erodent. The steady state experiments indicate that the greatest specific erosion rate is at 60° and minimum at 30°. Due to the presence of interlayer, specific erosion rate decreases with the increase in the thickness of the coatings. Surface topography of the eroded samples indicate a decrease in surface roughness with increase in impact velocity. Thereafter, Taguchi (L16) orthogonal array has been utilized in order to optimize the input parameters. Analysis of variance has been applied to determine the contribution of individual control factors. The results from Taguchi experiments and analysis of variance find the order of dominance of control factors and their individual contribution as: velocity (47.31 %) > coating thickness (29.94 %) > angle (13.26 %) > erodent feed rate (7.65 %). Coatings have exhibited a semiductile wear behavior. [ABSTRACT FROM AUTHOR]

Machine hammer peening is a surface treatment technique employed to enhance the surface properties of the treated samples. In this present work, the theoretical analysis, finite element simulation and experiment of single peening are carried out to investigate the relationship between the machine hammer peening force and geometric dimensions of the single peening indentation deformation, including diameter and depth. The single peening experimental results are in accordance with theoretical and simulation analysis. The machine hammer peening experiment with grate tool path are done and the results including surface topography, surface roughness, surface hardness, x‐ray diffraction analysis and wear resistance are discussed. This work seeks to explore the effects of process parameters like machine hammer peening force, indentation and pitch spacing on surface roughness and hardness. The results reveal that the surface hardness and roughness are positively associated with machine hammer peening force and small indentation and pitch spacing lead to high hardness. The x‐ray diffraction analysis validate machine hammer peening is a mechanical treatment without new compound generated. The friction test results in an enhancement in wear resistance of treated samples. [ABSTRACT FROM AUTHOR]

In this work, the structure of silica thin films synthesized with three different SiO2 precursors and obtained by the sol–gel method and dip coating technique was studied. Additionally, the influence of Ag addition on the obtained silica sols and then gel structure was investigated. Silica coatings show antireflective properties and high thermal resistance, as well as hydrophobic or hydrophilic properties. Three different silica precursors, TEOS (tetraethylorthosilicate), DDS (dimethyldietoxysilane) and AerosilTM, were selected for the synthesis. DDS added to silica sol act as a pore size modifier, while Ag atoms are known for their antibacterial activity. Coatings were deposited on two different substrates: steel and titanium, dried and annealed at 500 °C in air (steel substrate) and in argon (titanium substrate). For all synthesized films, IR (infrared) spectroscopic studies were performed together with GID and XRD (Grazing Incidence Diffraction, X-ray Diffraction) measurements. The topography and morphology of the surface were traced by SEM and AFM microscopic methods, providing information on the samples' roughness, particle sizes and thickness of the particular layers. The wetting angle values were also measured. GID and XRD measurements pointed to the distinct contribution of an amorphous phase in the samples, allowing us to recognize the crystalline phases and calculate the silver crystallite sizes. The FTIR spectra gave information on the first coordination sphere of the studied samples. [ABSTRACT FROM AUTHOR]

This study evaluates the potential of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation to modify the titanium surface for optimal seeding of fibroblasts and osteoblasts in the treatment of peri-implantitis. Titanium discs were treated using the Er,Cr:YSGG laser, an ultrasonic device with a stainless tip, or titanium scalers. Changes in surface properties were analyzed by profilometer and scanning electron microscopy (SEM). Murine fibroblast and osteoblast adhesion and proliferation were evaluated qualitatively and quantitatively at 24 and 72 h. Profilometric surface topography and SEM showed that titanium scalers and ultrasonic debridement techniques significantly changed the structure of the machined and rough titanium surfaces. The Er,Cr:YSGG laser irradiation, on the other hand, did not alter titanium microstructures. The Er,Cr:YSGG laser irradiation with the 40 Hz group showed a significantly higher attached fibroblast cell numbers than the titanium scaler group at 72 h after treatment (p = 0.023). Additionally, the number of the attached osteoblasts in the Er,Cr:YSGG laser irradiation with the 40 Hz group was significantly higher than that of the no-treatment groups 24 h after treatment (p = 0.045). The Er,Cr:YSGG laser effectively promoted adherence of fibroblasts and osteoblasts to the titanium surface without significantly altering the titanium surface, suggesting its superiority for treating peri-implantitis. [ABSTRACT FROM AUTHOR]

Chemical polishing or chemo‐mechanical polishing is crucial as a last step of surface preparation to remove the damaged layer and contaminants from the surface of CdZnTe crystals. The bromine–methanol solution is widely used for this purpose. However, bromine–methanol solution enriches the surface with Te and results in poor performance of CdZnTe crystals. In this study, the effect of the chemical polishing with 5% bromine–methanol solution on the surface and at the interface is investigated and it is demonstrated that etching duration strongly influences surface stoichiometry and interface contaminants. The evolution of the surface topography with etching and chemical changes are presented. It is shown that after 90 s etching/polishing, subsurface damage is removed and Te enrichment is minimum. Moreover, interface layer thickness is the smallest for 90 s etching duration. It is presented that further increase in the etching duration disturbs the surface stoichiometry and interface depth. It also calculated that 90 s of etching shows low interface barrier and symmetrical current–voltage curve. [ABSTRACT FROM AUTHOR]

The influence of surface topography on stem cell behavior and differentiation has garnered significant attention in regenerative medicine and tissue engineering. The cell-imprinting method has been introduced as a promising approach to mimic the geometry and topography of cells. The cell-imprinted substrates are designed to replicate the topographies and dimensions of target cells, enabling tailored interactions that promote the differentiation of stem cells towards desired specialized cell types. In fact, by replicating the size and shape of cells, biomimetic substrates provide physical cues that profoundly impact stem cell differentiation. These cues play a pivotal role in directing cell morphology, cytoskeletal organization, and gene expression, ultimately influencing lineage commitment. The biomimetic substrates' ability to emulate the native cellular microenvironment supports the creation of platforms capable of steering stem cell fate with high precision. This review discusses the role of mechanical factors that impact stem cell fate. It also provides an overview of the design and fabrication principles of cell-imprinted substrates. Furthermore, the paper delves into the use of cell-imprinted polydimethylsiloxane (PDMS) substrates to direct adipose-derived stem cells (ADSCs) differentiation into a variety of specialized cells for tissue engineering and regenerative medicine applications. Additionally, the review discusses the limitations of cell-imprinted PDMS substrates and highlights the efforts made to overcome these limitations. [ABSTRACT FROM AUTHOR]

Anomaly detection of three-dimensional (3D) topographic data is a challenging problem in spatial data analysis. In this paper, we investigate spatial patterns of 3D surface data that exhibit multiple in-control modes. In complex manufacturing processes, surfaces of final products could contain different topographic features from one in-control surface to another, thus making it difficult to monitor the surface with existing approaches, which rely on the assumption of the presence of single mode surface topography. We propose a novel anomaly detection approach for monitoring local topographic variations in the presence of multimode surface topography. We present a binarization model to capture the generic behavior of the multimode surfaces and enhance the representation of the surface. To systematically monitor the surface, we introduce a new probabilistic distance measure (PDM) that quantifies the similarity of spatial patterns between two binarized surfaces. The proposed PDM takes advantage of identifying local variations by utilizing the order neighbor statistics, which captures the local property on the surface. Experimental results with numerical simulation data and real-life paper surface data are provided to demonstrate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Study Design. A multicenter randomized controlled noninferiority trial with intrapatient comparisons. Objective. The aim of this study was to determine noninferiority of a slowly resorbable biphasic calcium phosphate with submicron microporosity (BCP<µm, MagnetOs Granules) as an alternative for autograft in instrumented posterolateral fusion (PLF). Summary of Background Data. Successful spinal fusion with a solid bone bridge between the vertebrae is traditionally achieved by grafting with autologous iliac bone. However, the disadvantages of autografts and unsatisfactory fusion rates have prompted the exploration of alternatives, including ceramics. Nevertheless, clinical evidence for the standalone use of these materials is limited. Methods. Adults indicated for instrumented PLF (1 to 6 levels) were enrolled at 5 participating centers. After bilateral instrumentation and fusion-bed preparation, the randomized allocation side (left or right) was disclosed. Per segment 10 cc of BCP<µm granules (1 to 2 mm) were placed in the posterolateral gutter on one side and 10 cc autograft on the contralateral side. Fusion was systematically scored on 1-year follow-up CT scans. The study was powered to detect >15% inferiority with binomial paired comparisons of the fusion performance score per treatment side. Results. Of the 100 patients (57 ± 12.9 y, 62% female), 91 subjects and 128 segments were analyzed. The overall posterolateral fusion rate per segment (left and/or right) was 83%. For the BCP<µm side only the fusion rate was 79% versus 47% for the autograft side (difference of 32 percentage points, 95% CI, 23-41). Analysis of the primary outcome confirmed the noninferiority of BCP <µm with an absolute difference in paired proportions of 39.6% (95% CI, 26.8-51.2; p < 0.001). Conclusion. This clinical trial demonstrates noninferiority and indicates superiority of MagnetOs Granules as a standalone ceramic when compared to autograft for posterolateral spinal fusion. These results challange the belief that autologous bone is the most optimal graft material. [ABSTRACT FROM AUTHOR]

Summary: The plant cuticle is located at the interface of the plant with the environment, thus acting as a protective barrier against biotic and abiotic external stress factors, and regulating water loss. Additionally, it modulates mechanical stresses derived from internal tissues and also from the environment. Recent advances in the understanding of the hydric, mechanical, thermal, and, to a lower extent, optical and electric properties of the cuticle, as well as their phenomenological connections and relationships are reviewed. An equilibrium based on the interaction among the different biophysical properties is essential to ensure plant growth and development. The notable variability reported in cuticle geometry, surface topography, and microchemistry affects the analysis of some biophysical properties of the cuticle. This review aimed to provide an updated view of the plant cuticle, understood as a modification of the cell wall, in order to establish the state‐of‐the‐art biophysics of the plant cuticle, and to serve as an inspiration for future research in the field. [ABSTRACT FROM AUTHOR]

As the only remaining ice sheet in the Northern Hemisphere, the Greenland ice sheet (GrIS) plays a crucial role in influencing atmospheric circulations, particularly with its rapid melting under global warming. In this paper, the influences of GrIS topography and surface thermal conditions are investigated by a series of aquaplanet experiments. The results show that the GrIS topography induces stationary waves and favors more blocking events through the generation of negative potential vorticity (PV) anomalies, while it tends to suppress local storm activities through the induced stationary waves. The surface cooling center of the GrIS is found to strengthen the jet streams by enhancing the meridional temperature gradient and thermal wind, while it causes the PV and static stability to increase during near-Greenland blocking days, thereby disfavoring blocking onset. Altogether, the topography and surface thermal effects of GrIS appear to compete with each other so that the net effect would determine the final response. Nevertheless, nonlinearity is found in both GrIS-topography alone and GrIS-surface temperature alone experiments, where nonlinear responses of atmospheric circulation are detected when the GrIS topography height or surface temperature exceeds their critical values, respectively. Hence, through this study, the response of the blocking in the vicinity of Greenland to the combined effects of topography and surface thermal conditions may shed light on comprehending the underlying mechanism of blocking alteration in a changing climate. Significance Statement: Although there have been numerous observation-based studies showing that the blocking around Greenland has increased over the past few decades, which is a predominant driver in accelerating the Greenland ice sheet (GrIS) melting, the reasons for this change are still unclear. In addition, the impact of GrIS on blocking still needs investigation. Through idealized aquaplanet simulations, this study examines the effect of GrIS's topography and surface thermal conditions upon blocking onset. It suggests the nonlinearity of the blocking response in the vicinity of Greenland to the combined effects in the variation of the height and surface temperature of GrIS. This study will enhance our understanding of possible changes in blocking due to global warming. [ABSTRACT FROM AUTHOR]

Many medical devices implanted in patients to mitigate diseases and medical conditions have different types of topographic features. While appropriate textures can promote the integration of host cells and reduce scar tissue formation, some textured implants with inappropriate topographies have been associated with inflammation, bacterial colonization, or even malignant complications. To better understand how surface topography affects host immune response to colonizing bacteria, a protocol was developed to investigate phagocytosis of bacterial cells attached on polydimethylsiloxane (PDMS) surfaces with different square-shaped recessive patterns. The interaction between activated RAW 264.7 macrophages and Escherichia coli in recessive wells was visualized in 3D using multiple fluorescent markers. The results revealed that there is a threshold dimension of topography, below which phagocytosis of attached bacterial cells is significantly impeded. Specifically, under our experimental condition, up to 100-fold reduction in phagocytosis was observed in square-shaped patterns with 5 µm side length and 10 µm depth compared to the flat control and patterns with 10 µm or longer side length. The spacing between wells also showed significant effects; e.g., phagocytosis in the wells further decreased when spacing increased to 50 µm. These results are helpful for understanding how undesired topographies may contribute to bacterial colonization and thus infection and other associated complications. Surface topography plays an important role in bacteria-material infections and thus the safety of implantable medical devices. Undesired topographic features can cause biofilm formation and related complications. However, how surface topography affects the capability of host immune cells to clear colonizing bacteria is not well understood. In this study, the interaction between macrophage RAW264.7 and colonizing E. coli cells on polydimethylsiloxane (PDMS) with recessive features is investigated. It was discovered that the size of recessive features and the spacing between these features have significant effects on phagocytosis of bacteria by macrophages. These new results are helpful for understanding the complex interaction among host cells, bacteria, and implanted biomaterials, which will help guide the rational design of safer medical devices. [Display omitted] [ABSTRACT FROM AUTHOR]

Osteoarthritis often requires surgical treatment with joint replacement. By using double modular hip endoprostheses, it is feasible to adapt the femoral angle to the patient and thus improve its biomechanics so that the anatomy of the patient can be better taken into account. Another advantage is that in case of damage of the taper, the stem can be left in the bone and only the neck adapter needs to be replaced. However, these advantages are accompanied by a higher risk of revision due to fretting of the additional connection. Fretting is influenced by angular deviations of the pairing. Therefore, the influence of the manufacturing-related angle deviations on the junction strength of the pairing Ti-6Al-4V ELI/ Ti-6Al-4V ELI and CoCr28Mo6/ Ti-6Al-4V ELI was investigated. Initially, outer tapers with two different surface topographies and defined angular deviation were manufactured. The tapers were joined with a static force of F assembly = 4 kN and subsequently the separation forces of the junction and the contact area after push-out tests were investigated. Material-specific differences regarding separation forces were found. The CoCr/Ti pairing shows greater average separation forces than the Ti/Ti pairing, although the resulting contact area of the Ti/Ti pairing is larger than the contact area of the CoCr/Ti. However, the resulting separation forces are independent of the investigated contact cases and the surface topography. This enables the adaption of tolerances within the manufacturing process to ensure the secure utilization of double modular hip endoprostheses. [ABSTRACT FROM AUTHOR]