Concave Surface Research Articles

Modeling and analysis of the equivalent convex mandrel of the three-dimensional braiding carbon fiber composite robotic arm

The third robotic arm (drive housing) of a six-axis industrial robot often has a vertical inwardly concave surface to facilitate the installation of spatially vertical drive motors. With the inwardly concave surface of the robotic arm it is difficult to realize three-dimensional (3D) braiding directly, and based on this problem, an equivalent convex mandrel is added to the concave mandrel. The mathematical model of the concave mandrel is established, and the mathematical expression of the concave mandrel is obtained. In any cross-section perpendicular to the x-axis, the equivalent outwardly convex cross-sectional line is obtained according to the condition that the length of the outwardly convex and concave mandrel cross-sectional line is equal. All outwardly convex cross-sectional lines form a smooth surface of the equivalent convex mandrel. By the numerical calculation method, the braiding trajectory and the downward pressure trajectory are predicted for various take-up speeds. The length error of the braiding trajectory and the downward pressure trajectory are within 5%, which verifies the accuracy of the convex mandrel. The variation pattern of the braiding angle is smooth, verifying the braidability of the convex mandrel. The experimental results show that the outwardly convex carbon fiber fabric can be pressed down to fit the surface of the concave mandrel. Therefore, a carbon fiber composite arm with an inwardly concave surface can be manufactured by 3D braiding with the addition of an equivalent convex mandrel.

Simulations suggest a scaffolding mechanism of membrane deformation by the caveolin 8S complex

Caveolins form complexes of various sizes that deform membranes into polyhedral shapes. However, the recent structure of the 8S complex was disk-like with a flat membrane-binding surface. How can a flat complex deform membranes into nonplanar structures? Molecular dynamics simulations revealed that the 8S complex rapidly takes the form of a suction cup. Simulations on implicit membrane vesicles determined that binding is stronger when E140 gets protonated. In that case, the complex binds much more strongly to 5- and 10-nm-radius vesicles. A concave membrane-binding surface readily explains the membrane-deforming ability of caveolins by direct scaffolding. We propose that the 8S complex sits at the vertices of the caveolar polyhedra, rather than at the center of the polyhedral faces.

Natural convection from solid and hollow cylinders with concave surface: A numerical approach

The buoyancy-driven thermofluid dynamics of a solid/hollow cylinder with concave surfaces have been studied in a laminar regime () using the finite-volume method to analyze the effects of ( and . Conservation equations for mass, momentum, and energy have also been solved in a 2-D axisymmetric geometry . Second-order upwind and central difference schemes have been deployed to discretize the convective and diffusive terms. Heat dissipation increases with irrespective of for both cylinders. However, the remains constant with the ratio for a hollow concave cylinder increases with whereas, decreases. Multiple vortices appear at the outside surface at a low (i.e. = 0.2), and these vortices almost disappear at high (i.e. = 0.6), affecting the outside average Nusselt number from low to high. In all cases, is higher than The thermofluid dynamics of solid and hollow cylinders have been delineated through different countour and vector plots, and two correlations for Nu have been deveoped.

Variation in human limb joint articular morphology.

Synovial joints in human limbs strike a balance between mobility, stability, and articular fit, yet little is known about how these conflicting demands pattern intraspecific variation in articular shape. In this study, we use geometric morphometrics to establish the apportionment and magnitude of morphological variance of the articular surfaces of the human shoulder, elbow, hip, and knee. We hypothesize that variances will be comparable between articulating surfaces within a joint and will be larger in joints with smaller ranges of motion, given their plurality of functional demands. Three-dimensional landmarks were taken on the articular surfaces of the glenohumeral, humeroulnar, acetabulofemoral, and tibiofemoral joints from CT scans of 200 skeletons from the University of Tennessee Donated Skeletal Collection (84 females, 116 males). Root mean-squared distances between articulations calculated from Procrustes shape coordinates were used to determine variance distributions. We found no difference in variances for each articular surface between the sexes or between left and right articular surfaces. A high range of motion is associated with greater morphological variance; however, this pattern is largely driven by the concave articular surfaces of each joint, which consistently exhibit statistically greater variance than their convex counterparts. The striking pattern of differential variance between articulating morphologies points to potential disparities in development between them. Consistently higher variance in concave surfaces may relate to chondral modeling theory for the formation of joints. Establishing intraspecific morphological variance patterns is a first step in understanding coordinated evolution among articular features.

Fabrication of Hyperbranched Photomechanical Crystals Composed of a Photochromic Diarylethene.

We report the fabrication of hyperbranched hollow crystals of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene on a concave surface of the spherical glass substrate by sublimation and their practical photomechanical behaviors. The number of units of the branched structure of the hollow crystals composed of this compound is proportional to the substrate curvature of the substrate. Compared with the sublimation process of the same compound on the flat glass substrate, two kinds of the thin film domains are generated separately in the center and around the edge of the spherical glass substrate. Especially under the high relative humidity condition, the boundaries between these thin film domains move gradually around the edge through the center during as long as 6 h of sublimation time so that the hyperbranched hollow crystals are densely produced on the entire surface of the substrate. These hyperbranched hollow crystals can be prepared with the highly ordered molecular packing due to the very slow formation process of the crystalline walls of the hollow structures. Furthermore, the photo-induced bending behaviors in the few- and highly-branched hollow crystals have the practical roles in moving and bending the minute objects according to their characteristics of these branched shapes.

Convective heat transfer from a spherical concave surface due to swirling impinging jets issuing from a circular pipe

Impinging jet heat transfer from curved surfaces is available in many industrial applications, such as cooling of gas turbine leading edge and deicing of airplane wing leading edge (heating). Most of the published studies on this topic involve non-swirling jet impingement from flat surfaces. Swirling jets are also used in some applications with the anticipation of heat transfer augmentation. Swirling impinging jet flow characteristics are significantly different from that of the non-swirling jet. However, fundamental studies of swirling jet impingement onto curved surfaces are very limited. As such, flow dynamics and convective heat transfer from a heated concave surface due to swirling impinging jets from a circular nozzle are numerically investigated using the RANS approach and the realizable k-ε turbulence model. Various flow and geometric parameters, such as the jet Reynolds number (Re) in the range of 11,600–35,000; the swirl number (Sw) in the range of 0–2.4; and the jet-to-surface separation distance (H) of 0.5–8 times the nozzle diameter, at a fixed impingement surface curvature (diameter) are studied. The results show that two counter-rotating recirculation zones appear near the target surface for near-field impingement (H ≤ 1) and higher swirl numbers (Sw ≥ 1.2), whereas for far-field impingements (H > 2), they are formed inside and outside of the main jet stream. An intense surface heat transfer zone develops only for near-field impingement in the range 1 ≤ S ≤ 3 at higher swirl numbers, where S is the distance along the impingement surface from the domain axis. More uniform thermal distribution along the curved surface is found for far-field impingement at Sw ≥ 0.8. Whilst the transitional Sw and H for Re = 11,600 are 0.8 and 2 respectively, the transitional Sw and H for Re = 35,000 are 0.8–1.2 and 4, respectively. Maximum heat transfer zones are found to be correlated with strong turbulence. Correlations are developed for the average Nusselt number as a function of the jet Reynolds number, jet exit to impingement surface separation distance, and swirling strength.

Treatment of Permanent Patellar Dislocation in Flexion by Patellar Osteotomy Combined with Modified Trochleoplasty and Tibial Tubercle Medialisation

Patellar dislocations in flexion, which occurs permanently with every movement, is the most serious manifestation of patellofemoral malalignment. Surgical approaches to correct this problem have been mostly unsuccessful. In a new therapeutic approach, the concave posterior surface of the patella, which slides on the hypoplastic lateral condyle as if guided by splints, is seen as the main pathology. The appropriate surgical strategy is trochleoplasty, combined with closed wedge patellar osteotomy, tuberosity medialisation, procedure for lengthening lateral retinaculum and MPFL plasty with the quadriceps tendon. In the case of a 13-year-old female patient presented here, this procedure leads to permanent stability in a symptom-free knee joint on both sides.

Comparison of Force During the Endotracheal Intubation of Commercial Simulation Manikins.

Background Medical simulation allows clinicians to safely practice the procedural skill of endotracheal intubation. Applied force to oropharyngeal structures increases the risk of patient harm, and video laryngoscopy (VL) requires less force to obtain a glottic view. It is unknown how much force is required to obtain a glottic view using commercially available simulation manikins and if variability exists. This study compares laryngoscopy force for a modified Cormack-Lehane (CL) grade I view in both normal and difficult airway scenarios between three commercially available simulation manikins. Methods Experienced clinicians (≥2 years experience) were recruited to participate from critical care, emergency medicine, and anesthesia specialties. A C-MAC size 3 VL blade was equipped with five force resistor reading (FSR) sensors (four concave surfaces, one convex), measuring resistance (Ohms) in response to applied pressure (1-100 Newtons). The study occurred in a university simulation lab.Using a randomized sequence, 49 physicians performed intubations on three manikins (Laerdal SimMan 3GPlus, Gaumard Hal S3201, CAE Apollo) in normal and difficult airway scenarios. The outcomes were sensor mean pressure, peak force, and CL grade. Summary statistics were calculated. Generalized estimating equations (GEEs) conducted for both scenarios assessed changes in pressure measured in three manikins while accounting for correlated responses of individuals assigned in random order. Paired t-test assessed for the in-manikin difference between scenarios. STATA/BE v17 (R) was used for analysis; results interpreted at type I error alpha is 0.05. Results Participants included 49 experienced clinicians. Mean years' experience was 4(±6.6); median prior intubations were 80 (IQR 50-400).Mean individual sensor pressure varied within scenarios depending on manikin (p<0.001). Higher mean forces were used in difficult scenarios (603.4±128.9, 611.1±101.4, 467.5±72.4 FSR) than normal (462.5±121.9, 596.0±90.5, 290.6±63.2 FSR) for each manikin (p<0.001). All manikins required more peak force in the difficult scenario (p<0.03). The highest mean forces (Laerdal, CAE, difficult scenario) were associated with the higher frequency of grade 2A views (p<0.001). The Gaumard manikin was rated most realistic in terms of force required to intubate. Conclusion Commercially available high-fidelity manikins had significant variability in laryngoscopy force in both normal and difficult airway scenarios. In difficult airway scenarios, significant variability existed in CL grade between manikin brands. Experienced clinicians rated Gaumard Hal as the most realistic force applied during endotracheal intubation.

Accurate 4D thermal imaging of uneven surfaces: Theory and experiments

Conventional IR thermography is basically a 3D imaging model: pixel position (2D) and temperature (1D). However, the surface roughness, which cannot be depicted by the 2D geometry imaging, may introduce significant error into the temperature measurement, especially in close range. Although there are some principle studies on this theme, quantitative tools for arbitrary-shaped surfaces is still lacking. In this work, we have developed an imaging system composed of a binocular camera using structured illumination and an IR camera to reconstruct 4D uneven surface thermal images. This 4D information includes the 3D geometry of the surface and the temperature mapping over it. Based on the highly accurate surface roughness image obtained, a meshed area calculation tool is used to establish a temperature self-correction module for rough/uneven surfaces, which include convex surface, concave surface or their combinations. The effective emissivity of convex as well as flat surface is easy to calculate, because is this case, there is no inter-radiation or reflection. On contrast, the determination of concave surface emissivity is still posed as a challenge. In this work, some theoretic gap was first filled and then the experimental verification was provided. The temperature-correction takes angle of view and emissivity calibration into account. The angle of view is relative to the position of the object point and the emissivity calibration is based on the 3D geometry of the uneven surfaces. An imaginary flat surface is used to provide an effective emissivity for a local roughness. Experimental results shows that without this temperatue-correction module, the deviations between IR thermography and thermocouple are from ∼2.35 °C (at 50 °C) to ∼4.96 °C (at 300 °C) and from ∼2.43 °C (at 50 °C) to ∼4.78 °C (at 300 °C), while after the correction, the deviations are from ∼0.12 °C (at 50 °C) to ∼0.20 °C (at 300 °C) and from ∼0.16 °C (at 50 °C) to ∼0.20 °C (at 300 °C). Utilizing the thermal imaging model for recorrection, the deviations are from ∼0.13 °C (at 50 °C) to ∼0.19 °C (at 300 °C) and from ∼0.16 °C (at 50 °C) to ∼0.19 °C (at 300 °C). This generalized solution paves the way for high-accuracy temperature measurement on complexly rough surface, especially for high temperature, at which the measuring deviation can be very large.

Synthesis of Butterfly-Like Shaped Gold Nanomaterial: For the Regulation of Liquid-Liquid Phase-Separated Biomacromolecule Droplets.

Nanotechnology is a critical tool to manipulate the sophisticated behavior of biological structures and has provided new research fields. Liquid-liquid phase-separated (LLPS) droplets gather attention asbasic reaction fields in a living cell. Droplets playcritical roles in regulating protein behavior, including enzyme compartmentalization, stress response, and disease pathogenesis.The dynamic manipulationof LLPS droplet formation/deformation has become a crucial target in nanobiotechnology. However, the development of nanodevices specifically designed for this purpose remains a challenge. Therefore, this study presents butterfly-shaped gold nanobutterflies (GNBs) as novel nanodevices for manipulating LLPS droplet dynamics. The growth process of the GNBs is analyzed via time-lapse electroscopic imaging, time-lapsespectroscopy, and additives assays.Interestingly, GNBs demonstrate the ability to induce LLPS droplet formation in systems such as adenosine triphosphate/poly-l-lysine and human immunoglobulin G, whereas spherical and rod-shaped gold nanoparticles exhibit no such capability. This indicates that the GNB concave surface interacts with the droplet precursors facilitating the LLPS droplet formation.Near-infrared-laser irradiation applied to GNBs enableson-demand deformation of the droplets through localized heat effects. GNBregulates theenzymatic reaction of lysozymes.The innovative design ofGNBs presents a promising strategy for manipulating LLPS dynamics and offers exciting prospects for future research.

Structural insights on the deformations induced by various mutations on cholesteryl ester transfer protein

Cholesteryl Ester Transfer Protein (CETP) is a plasma glycoprotein that intervenes the reverse cholesterol transport (RCT) by equimolar exchange of Cholesteryl esters (CE) and Triglycerides (TGs) between anti-atherogenic High-Density Lipoproteins (HDLs) and pro-atherogenic Low-Density Lipoproteins (LDLs) resulting in the increased concentration of CEs in LDL. This is a potential cause for the formation of atherosclerotic plaques in blood vessels leading to fatality. Therefore, blocking the function of CETP has emerged as a novel strategy for suppressing atherosclerotic plaques. The crystal structure of CETP revealed two Cholesteryl esters (CEs) in the hydrophobic tunnel and two phospholipids (PLs) plugged on the concave surface. Previous lipid transfer assay experimental studies have shown a substantial reduction in the neutral lipid transfer in [R201S] and [I443W, V198W] mutants. However, the protein conformational arrangements due to the mutations present in the CETP system leading to a decrease in the transfer rate of neutral lipids is not explored. Thus, I explored the reason behind the decreased transfer rate in mutants using molecular dynamics (MD) simulations and free energy calculations. Resulting evidences show that R201S mutant induces unfavorable bending angle to CETP with a decreased binding efficiency between N-terminal phospholipid of CETP with S201. Also, an unfavorable conformation state of TGs is formed which makes them difficult to transfer across CETP. Likewise, [I443W, V198W] mutant induces unfavorable CE, TG, and bending angle conformation to CETP impeding neutral lipid transfer. Thus, my results provide sufficient insights on the causation for a decreased transfer rate as reported earlier. The detailed understanding obtained here could help in developing a new strategy in preventing the function of CETP by blocking the role of potential hot spot residues.

Heat transfer in a rotating impingement cooling channel with concave target surface

Jet impingement cooling is a common technique for cooling the leading edge of turbine blades that experience high thermal loads. This study examines the effect of rotation on jet impingement cooling by conducting experiments in a rotating channel with a concave target surface. The dimensionless parameters of the jet configuration are 3 for both jet-to-jet spacing and jet-to-target surface spacing. The jet rotation number and jet buoyancy number reach a maximum of 0.26 and 0.63, respectively. The jet Reynolds number ranges between 5,000 and 15,000. The results show that a large vortex is generated in the supply channel due to the Coriolis force, which changes the mass-flowrate distribution in each jet hole. Therefore, the heat transfer in both ends increases while that in the middle region decreases, resulting in a U-shaped heat transfer distribution in the radial direction. In addition, the rotational Coriolis force is the dominant factor that affects the rotating jet impingement cooling, while the buoyancy force can affect heat transfer at high rotation numbers. The rotation-to-stationary Nusselt number ratio is defined to separate the effects of the Reynolds number, thus, the heat transfer correlations are developed between Nusselt number ratio and rotation number.

Structural Insights into Protein-Ligand Interactions of Small Leucine Rich Repeat Proteoglycans with a Large Number of Binding Partners: An Overview

Small leucine rich repeat proteoglycans (SLRPs) exist in the extracellular matrix. SLRPs contain tandem arrays of LRRs flanked by cysteine clusters at the both N- and C-termini. The extreme N- and/or C-termini contain low complexity sequences, glycosaminoglycan (GAG) chain and/or sulfated tyrosine residues in some members of SLRPs. The LRR solenoid structure may be divided into four parts consisting of a concave surface, an ascending surface, a convex surface, and a descending surface. SLRPs share many biological functions including collagen fibrillogenesis, signaling, innate immunity, and inflammation through the binding of various ligands. We undertake a comprehensive literature search of publications in order to make a list of ligands of SLRPs. We describe and discuss the interacting sites of SLRPs to binding partners. The protein-ligand interactions occur on not only the concave surface but also the ascending surface and the N- or C-terminal capping regions. In addition, the extreme N- and/or C-terminal regions with the GAG chains or sulfated tyrosine residues participate in ligand-interactions.

Water-Dispersible Carbon Nano-Test Tubes as a Container for Concentrated DNA Molecules.

Water-dispersible carbon nano-test tubes (CNTTs) with an inner and outer diameter of about 25 and 35 nm, respectively, were prepared by the template technique and then their inner carbon surface was selectively oxidized to introduce carboxy groups. The adsorption behavior of DNA molecules on the oxidized CNTTs (Ox-CNTTs) was examined in the presence of Ca2+ cations. Many DNA molecules are attracted to the inner space of Ox-CNTTs based on the Ca2+ -mediated electrostatic interaction between DNA phosphate groups and carboxylate anions on the inner carbon surface. Moreover, the total net charge of the DNA adsorbed was found to be equal to the total charge of the carboxylate anions. This selective adsorption into the interior of Ox-CNTTs can be explained from the fact that the electrostatic interaction onto the inner concave surface is much stronger than that on the outer convex surface. On the other hand, the desorption of DNA easily occurs whenever Ca2+ cations are removed by washing with deionized water. Thus, each of Ox-CNTTs works well as a nano-container for a large amount of DNA molecules, thereby resulting in the occurrence of DNA enrichment in the nanospace.

Mach reflection of detonation waves over a porous concave wedge

An experimental study of the differences in the Mach reflection process over smooth and porous concave wedges was systematically performed based on soot track measurement. Meanwhile, the interaction mechanism among the incident detonation, the Mach stem, and the porous wall was analyzed in detail. The results show that introducing multiple pores on the concave surface induces an additional attenuation region. In contrast, the triple-point over porous wedges starts traveling later and ends up colliding with the concave surface earlier. Moreover, the Mach stem height is shorter at the same wall position. For the transition angle of Mach-to-regular reflection over porous wedges, it is found to be negatively correlated with the length-scale ratio R/λ of the radius of curvature (R) to the cell size (λ), gas instability, and porosity. Although the experimental transition angle disagrees with the Chester–Chisnell–Whitham (CCW) and the reactive CCW theories, it is in agreement with the trend over smooth wedges that the experimental transition angle approaches to reactive CCW theory as R/λ increases. For the triple-point trajectory, it is almost a straight line when wall angle θ≤30° at R = 522 mm. It is also found that the triple-point trajectory is similar at the beginning for different mixture compositions at an equivalent initial pressure. The height of the Mach stem is shorter over a porous wedge with higher porosity, but it reaches a maximum value at a wall angle of 30° for wedges. Moreover, the Mach stem height decreases with increasing initial pressure or gas instability.

Reliable non-destructive detection and characterization of material degradation caused by high-temperature corrosion

Components made from nickel-based superalloys are widely used in gas turbines for aircraft and power plants. In addition to high corrosion resistance, they feature very good creep and fatigue strength at temperatures near 1000 °C. Yet, corrosive attack can significantly reduce the mechanical properties, and thus the expected remaining service life of these components. Therefore, in the case of safety-critical parts, detailed information on the component’s actual condition is crucial. In the present study, a non-destructive electromagnetic testing technique was developed that is capable of reliably detecting early degradation caused by high-temperature corrosion on components made of nickel-based alloys. The testing technique combines the use of temperature-resistant sensors and a variation of the component temperature in a wide range. This allows the determination of the magnetic properties of the component as a function of temperature. It was shown that the measurement signals obtained correlates with the degree of chromium depletion. Thus, a reliable and non-destructive detection of degradation caused by high-temperature corrosion was possible. A special feature of the presented testing technique is that degradation can be detected at an earlier stage compared to conventional methods. In addition, the technique enables the characterization of the microstructure condition directly in the component. The applicability of the testing technique was demonstrated for components with concave surface geometries, like turbine blades.

Adaptation peculiarities of the liver structure in some representatives of the order Lagoriform

The work is devoted to the study of the adaptive features of the histological structure of the liver of some representatives of the hare order. The material for the study was organocomplexes from clinically healthy productive rabbits, decorative rabbits and white hare. Research work was carried out at the Department of Anatomy and Physiology of the Federal State Budgetary Educational Institution of Higher Education of the State Agrarian University of the Northern Trans-Urals. Conducted morphometric studies and selected material for morphological and histological studies. The liver of the studied species of the order Lagomorphs has a convex parietal and slightly concave visceral surface. The right and left lobes of the liver are divided into lateral and medial parts. In a productive rabbit and a decorative rabbit, the lateral right lobe is shorter than the lateral left lobe, and in the white hare, both of these are short. The square share of all is an elongated quadrangular shape. Caudate and mastoid processes are small. The gallbladder lies between the right lateral and right medial lobes and does not extend beyond the ventral edge of the liver. Histological studies were carried out according to generally accepted methods. In all species of the order of lagomorphs, formed triads were observed located on the border between the lobules. Hepatocytes form hepatic laminae. Trabeculae and loose fibrous connective tissue are not expressed. Analyzing the obtained histological data, we can say that the adaptive features will include: in rabbits bred under industrial conditions - an increased area of hepatocytes (376.29±22.95 µm2) and nuclei (52.44±4.51 µm2), a decrease in NCR 0.16±0.007; in ornamental rabbits - a decrease in the area of hepatocytes (38.32±1.77 µm2) and nuclei (7.06±0.59 µm2), but the average value of the Nuclear-Cytoplasmic Ratio is 0.42±0.01; in the hare - the average values of the area of hepatocytes (260.79±15.88 µm2) and nuclei (41.58±1.32 µm2), NCR 0.4±0.01. These features indicate significant differences in the nutrition and maintenance of these animals, as well as various adaptation processes.

The Radius of Curvature of the Inferior Distal Clavicle Is Similar to That of the Glenoid in Both the Axial and Coronal Planes and Similar to the Inferior Coracoid

The purposes of this study were to use computed tomography (CT) scans to compare the radius of curvature (ROC) of the inferior concave surface of the distal clavicle to the glenoid, determine graft dimensions, and compare the ROC of the congruent-arc distal clavicle autograft (DCA) to the congruent-arc Latarjet graft. Patients who underwent bony glenoid reconstruction via a Laterjet procedure between January 2018 and January 2023 at a single institution were retrospectively identified. CT scans were used to measure the ROC of the glenoid on the axial and coronal sequences, measure the ROC of the distal clavicle on the sagittal oblique sequences, and determine the dimensions of the distal clavicle and coracoid graft. A total of 42 patients were included (Latarjet, n= 22; control, n= 20). Themean ROC of the inferior surface of the distal clavicle was not significantly different from the ROC of the glenoid in the coronal (P= .15) or axial planes (P= .65). The ROC of the coracoid when measured in the sagittal plane was not significantly different from the ROC of the distal clavicle (P= .25). The length, depth, and surface area of the coracoid in the congruent arc orientation were significantly larger than the distal clavicle (P < .005). Patients in the control group tended to have both a larger inferior clavicle ROC and a larger coracoid ROC compared to the Latarjet group (32.8 mm vs 29.6 mm, P < .0001; 31.8 mm vs 30.9 mm, P= .02). The ROC of the inferior distal clavicle is similar to that of the glenoid in both the axial and coronal planes and similar to the inferior coracoid. CT analysis reveals that the congruent-arc DCA technique provides a robust graft with dimensions that are suitable for reconstruction of the anterior glenoid.

Direct Manufacturing Technology for High‐Precision Follow‐the‐Shape Circuits on Complex, Hard, Curved Surfaces

Abstract3D curved electronics are a trend in the microelectronics industry, but conformal printing of circuits on complex curved surfaces remains challenging, especially for electronics comprising concave surfaces with large curvature. In this study, a new manufacturing method is proposed for follow‐the‐shape circuits, using high‐precision direct printing technology to print circuits on hard, arbitrarily curved surfaces. A circuit with any complex curved surface can be directly digitized and programmed for fully autonomous and controlled printing without indirect transfer or pad printing processing. The proposed direct printing method begins with using unique 3D projection technology to map a 2D planar functional circuit onto a 3D digital curved surface. The next step is directly printing the integrated circuit on a complex surface by controlled planning of the spatial motion trajectory, high‐frequency drive control of the precision nozzle, and precise switching control of the heterogeneous functional material. Optimal printing parameters are obtained by exploring the main factors affecting molding quality and electrical conductivity of curved surface circuits. Simple examples, such as an acoustic‐optic touch time‐delay three‐control multifunction system, demonstrate the feasibility and broad potential of the proposed technology.

A modified dynamic contact angle model applied to double droplet impact curved surface

The microscopic processes involving droplet impact and interaction on spatially curved surfaces remain unclear. In this study, we implement a dynamic contact angle model with adjusted upper and lower limits into a simulation of droplet motion, constructing a three-dimensional numerical model to depict the dynamics and heat transfer characteristics of symmetric double droplets impacting plane, concave, and convex cylindrical, and concave and convex spherical surfaces. The processes of droplet spreading, retraction, rebound, splitting, and heat transfer are elaborated, revealing the role of surface curvature during impact. Our results show that different curvatures significantly affect the flow morphology of the flow dividing line. For the two main curvatures of the surface, the curvature in the direction of droplet arrangement predominates. Positive curvature promotes spreading and repels the liquid phase, while negative curvature promotes agglomeration and attracts the liquid phase. Extreme situations arise when both positive and negative curvatures occur simultaneously. Regarding heat transfer, the overall heat transfer rate is mainly determined by the spread area, and the heat transfer performance of convex surfaces is better than that of plane or concave surfaces. Residual bubbles increase heat transfer inhomogeneity, but different surfaces do not show significant variability. Additionally, the heat flow intensity in the central interaction region has the following relationship with its rebound height and is independent of the overall heat transfer intensity.