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Herein, a simulation model is proposed that combines the lattice Boltzmann method (LBM) and a magnetic particle model to observe particle ring patterns in evaporating sessile droplets, controlling them using a magnetic field. Brownian dynamics and van der Waals force models are applied to the nanoparticles. The interactions between the magnetic particles are simulated using the magnetic particle model, which is validated using previous experimental particle distribution results. The particle deposition patterns are compared according to the substrate wetting conditions. The distribution exhibited a clear coffee-ring pattern as the pinning time of the contact line increased. In the case of a non-pinned droplet, the thermal Marangoni flow was maintained, and the adhesion of the particles was delayed by the vortex. A thick, uniform ring pattern was formed when a magnetic field was applied to the particles. The particle bundles formed by the magnetic field were resistant to flow. To verify this result, the average particle velocity was measured. Consequently, particle transfer was classified into three stages. In Stage I, capillary force dominates, Marangoni flow develops in Stage II, and particle adhesion occurs in Stage III. With an increase in the magnetic strength, the velocity change exhibited a decrease across all stages. [ABSTRACT FROM AUTHOR]

The fixed life pattern of plants is the most threatening factor that hinders the survival and reproduction rate of plants. Maximization of reproduction is determined by the survival rate of the organism. If part of a shoot apical meristem or root apical meristem is cut and planted in soil with appropriate nutrients and survival conditions, a cloned plant known as an ramet, may be developed. Therefore, the ability of plants to constantly produce meristems is essential for survival. In addition, meristem stem cells have enabled plants to evolve a wide variety of asexual reproductive systems. When a tree is pruned, at least one or more new meristems are formed in the surrounding area, and those meristems develop into new branches. In other cases, stem cells normally derived from meristems alone exhibit the potential for asexual reproduction through their seed-like roles. Alternatively, some plants can form somatic cells, which are important in various types of asexual reproduction. There are 125 species of plants in the genus of Kalanchoe , which are succulent plants, and most of these species are well known to reproduce asexually through somatic cells. When we cut the stem of a plant, a callus is formed at the end of the cut side. Plant callus is mainly used to develop new plant varieties in tissue culture research. Alternatively, the plant callus is also used as a material for asexual reproduction. Callus can also form if the plant is infected with bacteria such as Agrobacterium tumefaciens. Differentiated cells of a plant can reproduce asexually by acquiring the ability to function as stems through transdifferentiation. These characteristics play important roles in adapting to environmental changes and extending the lifespan of woody plants. [ABSTRACT FROM AUTHOR]

Background: Laparoscopic surgery for T4 colon cancer may be safe in selected patients. We hypothesized that small tumor size might preoperatively predict a good laparoscopic surgery outcome. Herein, we compared the clinicopathologic and oncologic outcomes of laparoscopic and open surgery in small T4 colon cancer. Methods: In a retrospective multicenter study, we reviewed the data of 449 patients, including 117 patients with tumors ≤ 4.0 cm who underwent surgery for T4 colon cancer between January 2014 and December 2017. We compared the clinicopathologic and 3-year oncologic outcomes between the laparoscopic and open groups. Survival curves were estimated using the Kaplan–Meier method and compared using the log-rank test. Univariate and multivariate analyses were performed using the Cox proportional hazards model. A p < 0.05 was considered statistically significant. Results: Blood loss, length of hospital stay, and postoperative morbidity were lower in the laparoscopic group than in the open group (median [range], 50 [0–700] vs. 100 [0–4000] mL, p < 0.001; 8 vs. 10 days, p < 0.001; and 18.0 vs. 29.5%, p = 0.005, respectively). There were no intergroup differences in 3-year overall survival or disease-free survival (86.6 vs. 83.2%, p = 0.180, and 71.7 vs. 75.1%, p = 0.720, respectively). Among patients with tumor size ≤ 4.0 cm, blood loss was significantly lower in the laparoscopic group than in the open group (median [range], 50 [0–530] vs. 50 [0–1000] mL, p = 0.003). Despite no statistical difference observed in the 3-year overall survival rate (83.3 vs. 78.7%, p = 0.538), the laparoscopic group had a significantly higher 3-year disease-free survival rate (79.2 vs. 53.2%, p = 0.012). Conclusions: Laparoscopic surgery showed similar outcomes to open surgery in T4 colon cancer patients and may have favorable short-term oncologic outcomes in patients with tumors ≤ 4.0 cm. [ABSTRACT FROM AUTHOR]

Among the various types of concurrency bugs, the data race is one of the primary causes of other concurrency bugs. Thus, it is important to detect as many data races as possible during the development step of multithreaded programs. A hybrid data race detection technique that uses the Lockset algorithm and happens-before relation, can detect actually occurred and hidden data races in one execution trace. However, high runtime slowdown obstructs the frequent use of hybrid detectors. In this paper, we empirically demonstrate that most data race bugs are caused by the absence of a lock, and that multiple locks are rarely involved in a data race bug in the real world. Thus, we propose a fast hybrid detection algorithm that does not introduce additional false positives and false negatives to the current hybrid detectors. The suggested algorithm replaces the lock-set intersection by a simple comparison operation that focuses on exploring data-race-prone locking patterns. The experimental results indicate that the proposed algorithm detects the same data races as Multilock-HB, which is the most accurate hybrid detector, with a 1.18 × slowdown of FastTrack for eight large-scale benchmark programs. [ABSTRACT FROM AUTHOR]

To explore the effects of wettability and surface tension on heat transfer in sliding bubble dynamics, we investigated the manner in which the dynamics of bubble sliding and heat transfer over a heated surface depend on the degree of wettability and the surface tension. Using the volume-of-fluid (VOF) method, the interface of the dispersed phase was tracked in terms of the local volume fraction. The obtained simulation results were consistent with those obtained from experimental studies. Although the heat transfer obtained when bubbles slid freely across the surface were strongly correlated with the skin-friction coefficient, deformability rather than skin friction dominated the heat transfer of bubbles adhering to the surface. The heat transfer rate increased with bubble deformability. • The effects of deformability on heat transfer in sliding bubble dynamics were explored. • The bubble completely adheres to the surface as the adhesion force is increased. • The bubble became more deformable with an increase in Weber number. • The bubble spreads more widely across the surface at a contact angle of 150°. • The highest heat transfer rate was observed in most deformable case. [ABSTRACT FROM AUTHOR]

Stick-slip motion is the most well-known phenomenon in nanotribology. Maier et al. previously studied the dependence of slip time on contact geometry. In their paper, they were able to identify the intermediate state during slip motion. However, detailed study of this intermediate state is difficult due to the fast dynamics. The advantage of molecular dynamics (MD) simulation is that it can provide detailed information and direct visualization of the tribological phenomena on a time scale of a few nanoseconds. In this paper, we investigate the detailed mechanism of stick-slip motion in nanoscale. MD simulation precisely mimics friction force microscopy experiments. In MD simulations, a crystalline Si tip slides on a graphene surface, and the tip size is varied. The simulation results provide evidence of the intermediate state during slip motion and reveal the hierarchical structure of the stick-slip motion in nanoscale. Detailed relations among stick-slip motion, contact geometry, and energy state are also analyzed. [ABSTRACT FROM AUTHOR]

This paper proposes a novel method for controlling the boiling phenomena of a thermally heterogeneous field on a surface. To achieve thermal heterogeneity, we used a heat flux gradient. The control method is based on radial pitch control of the patterned wettability using hydrophobic dots. The area fraction of the hydrophobic dots was set to be small near the center of the hot-spot and large in the marginal region. Consequently, the boiling phenomena at the center changed from a film boiling regime to a nucleate boiling regime. Compared with an uncontrolled surface, the critical heat flux was enhanced at the center region, and the heat transfer rate was enhanced at the marginal region. Pitch control prevents film generation at the center and film propagation over the whole surface, thus enhancing the overall critical heat flux of the whole surface. [ABSTRACT FROM AUTHOR]

Conventional patterned wettability with a periodic checkerboard pattern shows intermediate critical heat flux (CHF) between uniform hydrophilic and hydrophobic surfaces. To solve this high superheat problem and maintain the high CHF, we propose adaptive fraction control of the pitch of hydrophobic dots. With actual heat source, the temperature distribution is the highest at the center and decreases as the radius from the center increases. Patterned wettability in the high temperature region is created with a low area fraction of hydrophobic dots, while the area fraction gradually increases with distance from the center. Using this adaptive fraction control, CHF can be avoided in the center region and superheat can be dropped for nucleation in the outer region at low temperature. However, if the concentration gradient of hydrophobic dots is too large, nucleation at the center of surface will be suppressed and boiling crisis will occur in the outer region. Therefore we also optimized the concentration of hydrophobic dots with respect to CHF and start of nucleation. In this research, a multiphase single component lattice Boltzmann model was used for the simulation. The simulation model is modified to establish heterogeneous wettability. The effects of size and concentration of hydrophobic dots are analyzed by observing the tendency of CHF, superheat, and local Nusselt number. [ABSTRACT FROM AUTHOR]

To explore the effect of hydrophobicity on cloud cavitation, the behaviors of cloud cavitation over the Clark-Y hydrofoil under various slip condition were investigated. Large eddy simulation (LES) was used for the turbulence model. The mass transfer model, which was considered to be a two-phase mixture flow, was used for the vaporization and condensation processes in the transport equation. The volume of fluid (VOF) scheme was used to track the interface of the dispersed phase by using the local volume fraction. Slip strength was controlled using the friction coefficient. The cavitation model in this study agreed with experimental and previous numerical studies. The results show that as the slip strength grew stronger, the friction drag was reduced; the cavity became longer and the shedding frequency decreased. For this reason, cloud cavitation is stabilized in condition of strong slip strength. Thus, a relatively weak re-entrant jet occurs in conditions of strong slip strength which gives rise to small amount of vapor shedding at the closure. This means that cloud cavitation instability was alleviated as the hydrophobicity increased. [ABSTRACT FROM AUTHOR]

Abstract: This paper proposes an extension scheme for the application of the single phase multi-block lattice Boltzmann method (LBM) to the multiphase Gunstensen model, in which the grid is refined in a specific part of the domain where a fluid–fluid interface evolves, and the refined grid is free to migrate with the suspended phase in the flow direction. The method is applicable to single and multiphase flows, and it was demonstrated by simulating a benchmark single phase flow around a 2D asymmetrically placed cylinder in a channel and for investigating the shear lift of 2D neutrally buoyant drop in a parabolic flow. [ABSTRACT FROM AUTHOR]

Abstract: A finite volume formulation for large eddy simulation (LES) of turbulent pipe flows based on the compressible time-dependent three-dimensional Navier–Stokes equations in Cartesian coordinates with non-Cartesian control volumes is presented. The small scale motions are modeled by a dynamic subgrid-scale (SGS) model. A dual-time stepping approach with time derivative preconditioning is employed to enable the simulations to run efficiently at low Mach numbers. The equations with primitive variables, (p, u, v, w, T), are solved with an implicit lower-upper-symmetric-Gauss–Seidel (LU-SGS) scheme. An isothermal turbulent pipe flow at two Reynolds numbers, and a turbulent pipe flow with a low heat transfer are simulated to evaluate this compressible LES finite volume formulation. The results agree very well with the experimental data and DNS results, verifying the accuracy of the present scheme. [Copyright &y& Elsevier]

Large eddy simulation of rotating channel and ribbed channel flows with and without heat transfer is reported. The rotation axis is parallel to the spanwise direction of the parallel plate channel. An implicit finite-volume scheme was used to solve the preconditioned time-dependent filtered Navier–Stokes equations using a dynamic subgrid-scale model to account for the subgrid-scale effects. The distribution of mean velocity and mean temperature were influenced by system rotation, transforming from a symmetric profile into a non-symmetric profile. The shift of peak values was toward the stable side of the channel.Near the stable (leading) side, the turbulent intensities and heat transfer were suppressed, but turbulence was enhanced with increasing shear stress and turbulent kinetic energy near the unstable (trailing) side. [Copyright &y& Elsevier]

The goal of the present study was to perform a large eddy simulation of vertical turbulent annular pipe flow under conditions in which fluid properties vary significantly, and to investigate the effects of buoyancy on the turbulent structures and transport. Isoflux wall boundary conditions with low and high heating are imposed. The compressible filtered Navier–Stokes equations are solved using a second order accurate finite volume method. Low Mach number preconditioning is used to enable the compressible code to work efficiently at low Mach numbers. A dynamic subgrid-scale stress model accounts for the subgrid-scale turbulence. Comparisons were made with available experimental data. The results showed that the strong heating and buoyant force caused distortions of the flow structure resulting in reduction of turbulent intensities, shear stress, and turbulent heat flux, particularly near the wall. [Copyright &y& Elsevier]

This in vitro study evaluated comprehensively the performances of zirconia brackets with varying yttria proportions in manufacturing advanced orthodontic brackets. Three experimental groups of zirconia brackets were fabricated using yttria-stabilized zirconia (YSZ) materials with different yttria proportions—3 mol% yttria (3Y-YSZ), 4 mol% yttria (4Y-YSZ), and 5 mol% yttria (5Y-YSZ) (Tosoh Ceramic, Japan). A polycrystalline alumina ceramic bracket (3M™ Clarity™ Advanced, MBT 0.022-in. slot) was employed as the control group. Morphological properties, including slot surface structure and dimensions, were examined using scanning electron microscopy and surface profiler analysis. Manufacturing accuracy was assessed with root mean square calculations of trueness and precision. Mechanical properties were tested, encompassing static and kinetic frictional resistance (FR) and fracture strength. Optical stability was evaluated through 20,000 cycles of thermocycling and a 7-day immersion in various coloring agents. Within the limitations of this study, zirconia brackets containing 3 to 5 mol% YSZ presented enhanced reliability in terms of dimensional accuracy and demonstrated favorable optical stability. Notably, owing to its advantageous mechanical properties, the 3Y-YSZ variant showed remarkable potential as an advanced material for fabricating orthodontic brackets. [ABSTRACT FROM AUTHOR]

Understanding the frictional properties of phosphorene is essential for reliable fabrication and sustainable operation of phosphorene-based nanotechnology devices. Although recent studies have revealed that phosphorene exhibits anisotropic frictional characteristics, the detailed mechanisms are not well analyzed, and the influence of some experimental parameters (e.g., spring stiffness, tip load force, and tip size), which are very sensitive to atomic frictional forces, were not considered. This study was carried out to address the above shortcomings. The anisotropic frictional behavior of phosphorene and its detailed mechanism were analyzed using potential energy profiles. Also, the effects of spring stiffness and tip load force on the stick-slip behaviors were investigated. Furthermore, we studied the sub-nanoscale stick-slip behavior during the nanoscale slip motion. The nanoscale and sub-nanoscale stick-slip phenomena were originated from the tip's behavior of passing over the bond between the phosphorus atoms and over the puckered honeycomb structure along the zigzag and armchair directions. We utilized a simple one-dimensional model to explain the energy profiles. The influence of tip size on the stick-slip behavior was also examined and found related to the initial nanoscale slip velocity. As the tip diameter decreased, a high-frequency sub-nanoscale stick-slip phenomenon and shorter nanoscale slip duration were identified. Unlabelled Image • Detailed mechanisms of anisotropic frictional characteristics of phosphorene are analyzed. • The influence of some experimental parameters (e.g., spring stiffness, tip load force, and tip size) on stick-slip behaviors was investigated in nano / sub-nano scale. • The nanoscale and sub-nanoscale stick-slip phenomena were affected by phosphorene lattice structure at each scan direction. [ABSTRACT FROM AUTHOR]

This paper analyzed colloidal characteristics of a bimodal distribution emulsion system using bulk rheological and numerical approaches. The experiment measured simple shear to confirm emulsion shear thinning and viscosity tendencies. Numerical models employed the multi-component lattice Boltzmann method to express interfacial tension, surfactant movement, and viscosity of liquid phases. Numerical models were helpful to implement interactions between two or more varied-sized liquid droplets, since they express droplet deformation and interaction forces and can also provide rheological analysis, whereas shear flow experiments cannot. In monodisperse systems (i.e., uniform droplet size), larger droplets decrease emulsion relative viscosity. However, mixture viscosity for bimodal systems (small droplets mixed with large droplets) was lower than that for the monodisperse system. The reduced viscosity was related to increased droplet deformability and decreased shear stress at the droplet surface. [ABSTRACT FROM AUTHOR]

In this study, the design of a solid propellant grain is optimized using neural networks. Variables must be balanced while designing a solid propellant grain to achieve the required performance. An optimized design is proposed for solid propellant grains with improved efficiency based on a neural network. Burning surface training datasets for grains created using various design variable values are obtained. Deep neural network, recurrent neural network, long short-term memory (LSTM), bidirectional LSTM, gated recurrent unit (GRU), and GRU-FC models are trained on the aforementioned training datasets, and their prediction accuracies are compared. The post-training model accuracy is evaluated by varying the amount of training data for the neural network that achieved the highest accuracy. By training a neural network using burning surface data for the target grain, the design variable values are predicted, and the model accuracy is verified. [ABSTRACT FROM AUTHOR]

A procedure for the treatment of tricuspid regurgitation through membrane insertion has been developed recently. However, membrane optimization is required to balance treatment effectiveness with valve damage. This optimization must be performed based on hemodynamic analyses, using the computational fluid dynamics method. The objectives of this study were to analyze hemodynamic features and provide guidelines for the patient-specific optimization of membranes. We used the lattice Boltzmann method for the base blood flow solver and the immersed boundary method to analyze the interactions among the membrane, leaflet, and blood flow. Optimization was performed by the membrane's volume and insertion angle, and the effects of the shape and surface contact angle of the membrane were observed. Among various patient-specific features, the annulus ratio, hematocrit, and age were selected as control variables. Hemodynamic features were classified as features related to treatment effectiveness, including the regurgitant volume, jet area, and pressure gradient, and those related to the valve leaflet thickening risk, including the Reynolds shear stress, turbulent kinetic energy, and vorticity magnitude. Our analysis results revealed that treatment effectiveness and leaflet damage have a tradeoff relationship; nevertheless, optimizing certain features such as the membrane shape or surface treatment can reduce damage. [ABSTRACT FROM AUTHOR]

In non-aqueous Li–air batteries, the liquid electrolytes penetrate the porous media such as carbon nanotube (CNT) paper structure, transport dissolved substances such as oxygen, and play a role in generating reactants on the surface of the porous media. Although the trapped air generated during the electrolyte penetration process could affect the oxygen transport and performance of the battery, this issue has not been sufficiently investigated. Therefore, in this study, the patterns of electrolyte penetration and air entrapment in porous media were investigated through numerical analysis. A multi-relaxation time color-gradient lattice Boltzmann method was employed for modeling. Based on a two-phase flow simulation in porous media, electrolyte penetration and trapped-air saturation were analyzed in terms of porosity, wettability, and viscosity ratio. The porosity and viscosity ratio did not considerably affect the trapped-air saturation, whereas wettability had a significant effect on the aforementioned parameter. In addition, for each variable, an increase in the effective diffusive coefficient corresponded to increased porosity and hydrophilicity, as well as an improved viscosity ratio. [ABSTRACT FROM AUTHOR]

Abstract: Atomic scale friction of graphene strongly depends on the commensurability which is related to the rotational motion. Despite the crucial role of the rotational motion of bi-layer graphene, there is no direct study of it. In this paper, the mechanism of the rotational motion of the graphene flake on graphene substrate using molecular dynamics simulations was studied. Simulation model with rotational force was developed to observe the friction behavior of graphene. Various parametric studies were performed by controlling variables such as flake size, load, orientation of rotational force and spring constant. Graphene flakes with commensurate orientations showed a clear stick-and-slip motion during the rotation. Variation of flake size and load affected adhesion force which caused the nonlinear friction behavior. Two specific stacking orientations, namely AA and AB stacking, showed relatively stable rotational motion compared to others. Translational motion was also observed simultaneously during slip event of AA and AB stacking orientation. Finally, based on these overall observations, the pathway of flake by rotation was explained along with the effect of spring constant. [Copyright &y& Elsevier]

Abstract: An Eulerian–Lagrangian based direct numerical simulations (DNS) model was developed to investigate the effective thermal conductivity of nanofluids. A two-way coupling term to resolve the temperature interactions between the solid particles and fluid field was considered. The model also considered various forces acting on the nanoparticles. Cu/water nanofluids with 100nm particles and Al2O3/water nanofluids with 80nm particles were simulated at different volume fractions and the effective thermal conductivity of nanofluids was calculated. The present results suggest that the particle conductivity and forces acting on nanoparticle are necessary while predicting the effective thermal conductivity of nanofluids. [Copyright &y& Elsevier]

• The flow boiling performance on patterned wettability was explored. • As the mass flux increases, the bubbles coalesce less and the bubble size stays small. • An HPoAF of 0.32 gave the best heat transfer performance. • For low mass fluxes, the parallel pattern gave the best heat transfer performance, but the dotted pattern performed better at high mass fluxes. During flow boiling in microchannels, the physics of a bubble is closely related to the heat transfer performance of different hydrophobic patterns. However, the heat transfer properties of various patterns are yet to be investigated. In this study, we conducted a numerical investigation into bubble coalescence characteristics and heat transfer performance of three patterns, namely crosswise, parallel, and dotted patterns, for flow boiling in a microchannel, and evaluated the influence of the hydrophobic area fraction for each pattern. In the transport equation, we employed a mass transfer model based on a two-phase mixture flow for the vaporization and condensation processes. In addition, we used the volume-of-fluid method to track the dispersed phase's interface using the local volume fraction. Although the parallel pattern at low mass flux facilitating bubble movement exhibited a good heat transfer performance, the dotted pattern displayed a better performance at high mass fluxes due to its higher nucleation site density. Additionally, very wide or narrow hydrophobic areas are unsuitable for heat transfer. Narrow areas limit bubble nucleation. A hydrophobic area fraction of 0.165 for the crossed pattern and of 0.32 for the parallel and dotted pattern produced the best heat transfer performances. [ABSTRACT FROM AUTHOR]

Abstract In this study, we analyze the near-wake characteristics of a 5-MW single wind turbine using a large-eddy simulation with the actuator line method. It is observed that stable helical structures of wake had breaking process due to flow instability with high-frequency turbulence in the analysis of turbulence energy spectra and auto-covariance. For vortical structure detection, the swirling strength criterion showed good performance when describing the tip vortices and their various streaklines. In the stable region, the stable helical structure of the tip vortices was observed with little wake recovery and flow instability. However, in the unstable region, the tip vortices had various streakline advection patterns such as horizontal, upward, and downward. In the statistical analysis of the flow acceleration, the distribution and magnitude of the acceleration in the stable and unstable regions were compared in terms of the probability density function, root mean square, and kurtosis. At the hub height and at the opposite blade tips in the stable region, the kurtosis of the acceleration was approximately 20 and 40, respectively. At the height wherein the wake recovery was dominant in the unstable region, the value of the kurtosis was 67. Highlights • We propose the stable wake region and the unstable wake region based on wake structure change and temporal velocity deficit change. • Turbulent characteristics and statistical properties of the vortex structure are analysed in a wake region of a wind turbine. • High-resolution vortical structure of wind turbine wake and its advection patterns are observed clearly. • Decay pattern of turbulence energy is obtained at different locations. [ABSTRACT FROM AUTHOR]

Recent studies have revealed that contact line forces play an important role in the droplet spreading process. Despite their significance, the physics related to them has been studied only indirectly and the effect of contact line forces is still being disputed. We performed a molecular dynamics simulation and mimicked the droplet spreading process at the nanoscale. Based on the results of the simulation, the contact line forces were directly calculated. We found that the forces acting on the bulk and the contact line region showed different trends. Distinct positive and negative forces, contact line spreading, and friction forces were observed near the contact line. We also observed a strong dependency of the atomic kinetics in the contact line region on the variations in the contact line forces. The atoms of the liquid in the contact line region lost their kinetic energy due to the contact line friction force and became partially immobile on the solid surface. The results of the current study will be useful for understanding the role of the contact line forces on the kinetic energy dissipation in the contact line region. [ABSTRACT FROM AUTHOR]

High-resolution large-eddy simulation of the flow over a large wind farm (64 wind turbines) is performed using the HIGRAD/FIRETEC-WindBlade model, which is a high-performance computing wind turbine–atmosphere interaction model that uses the Lagrangian actuator line method to represent rotating turbine blades. These high-resolution large-eddy simulation results are used to parameterize the thrust and power coefficients that contain information about turbine interference effects within the wind farm. Those coefficients are then incorporated into the WRF (Weather Research and Forecasting) model in order to evaluate interference effects in larger-scale models. In the high-resolution WindBlade wind farm simulation, insufficient distance between turbines creates the interference between turbines, including significant vertical variations in momentum and turbulent intensity. The characteristics of the wake are further investigated by analyzing the distribution of the vorticity and turbulent intensity. Quadrant analysis in the turbine and post-turbine areas reveals that the ejection motion induced by the presence of the wind turbines is dominant compared to that in the other quadrants, indicating that the sweep motion is increased at the location where strong wake recovery occurs. Regional-scale WRF simulations reveal that although the turbulent mixing induced by the wind farm is partly diffused to the upper region, there is no significant change in the boundary layer depth. The velocity deficit does not appear to be very sensitive to the local distribution of turbine coefficients. However, differences of about 5% on parameterized turbulent kinetic energy were found depending on the turbine coefficient distribution. Therefore, turbine coefficients that consider interference in the wind farm should be used in wind farm parameterization for larger-scale models to better describe sub-grid scale turbulent processes. [ABSTRACT FROM AUTHOR]

We present the results of measuring the viscometric flow of concentrated rigid-sphere suspensions with constant-viscosity matrices, both Newtonian (silicone oil) and non-Newtonian (Boger fluid: corn syrup (79.4%)–glycerin (19.8%)–4%PAA water (0.78%)). Various problems with the measurements are discussed, including settling due to density differences. The effect of sphere roughness on shear rheology is a main concern of the work. The viscosities of silicone oil and Boger fluid suspensions were increased by increasing sphere roughness, and the normal stress difference N 1 − N 2 in the Boger fluid suspension also increased with roughness. [ABSTRACT FROM AUTHOR]

• FFR prediction algorithm is optimized by performance within gray zone. • Synthetic models and CFD analysis are used to improve data quality and quantity. • Biometric features and flow features are used as input in FFR prediction algorithm. • Algorithm optimization is based on outlier elimination and k-fold cross validation. • Among eight algorithms, multilayer perceptron has shown highest performance. Recent attempts on adopting artificial intelligence algorithm on coronary diagnosis had limitations on data quantity and quality. While most of previous studies only used vessel image as input data, flow features and biometric features should be also considered. Moreover, the accuracy should be optimized within gray zone as the purpose is to decide stent insertion with estimated fractional flow reserve. The main purpose of this study is to develop an artificial intelligence-based coronary vascular diagnosis system focused on performance in the gray zone, from CT image extraction to FFR estimation. Three main issues should be considered for an algorithm to be used for pre-screening: algorithm optimization in the gray zone, minimization of labor during image processing, and consideration of flow and biometric features. This paper introduces a full FFR pre-screening system from automatic image extraction to an algorithm for estimating the FFR value. The main techniques used in this study are an automatic image extraction algorithm, lattice Boltzmann method based computational fluid dynamics analysis of a synthetic model and patient data, and an AI algorithm optimization. For feature extraction, this study focused on an automatic process to reduce manual labor. The algorithm consisted of two steps: the first algorithm calculates flow features from geometrical features, and the second algorithm estimates the FFR value from flow features and patient biometric features. Algorithm selection, outlier elimination, and k-fold selection were included to optimize the algorithm. Eight types of algorithms including two neural network models and six machine learning models were optimized and tested. The random forest model shows the highest performance before optimization, whereas the multilayer perceptron regressor shows the highest gray zone accuracy after optimization. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, we study the sedimentation of droplet onto horizontal surfaces using a Shan and Chen multicomponent lattice Boltzmann model [Shan and Chen, Phys. Rev. E 47, 1815(1993)]. Numerical simulations are performed for static nonwetting droplets and are compared with a theoretical model. Further simulations are performed using wetting droplets and changing the wetting characteristics of the surface. Novel study of droplet sedimentation with different wetting characteristics of wall surface shows three different regimes of droplet shapes. The process of different regimes can be controlled by changing the wetting characteristics of surface. It is observed that the droplet attains nonequilibrium region as the attraction force of surrounding droplet with the wall increases. This can lead to eventual breakup of the droplet. [ABSTRACT FROM AUTHOR]

• Created deep learning algorithm for automatic upper airway morphology segmentation. • Examined effect of data resolution on obstructive sleep apnea diagnosis accuracy. • Analyzed flow characteristics according to airway morphological factors. • Developed diagnosis obstructive sleep apnea method with flow characteristics and biometric features. • Suggest convenient and fast obstructive sleep apnea syndrome diagnosis method. Obstructive sleep apnea syndrome (OSAS) is being observed in an increasing number of cases. It can be diagnosed using several methods such as polysomnography. To overcome the challenges of time and cost faced by conventional diagnostic methods, this paper proposes computational fluid dynamics (CFD) and machine-learning approaches that are derived from the upper-airway morphology with automatic segmentation using deep learning. We adopted a 3D UNet deep-learning model to perform medical image segmentation. 3D UNet prevents the feature-extraction loss that may occur by concatenating layers and extracts the anteroposterior coordination and width of the airway morphology. To create flow characteristics of the upper airway training data, we analyzed the changes in flow characteristics according to the upper-airway morphology using CFD. A multivariate Gaussian process regression (MVGPR) model was used to train the flow characteristic values. The trained MVGPR enables the prompt prediction of the aerodynamic features of the upper airway without simulation. Unlike conventional regression methods, MVGPR can be trained by considering the correlation between the flow characteristics. As a diagnostic step, a support vector machine (SVM) with predicted aerodynamic and biometric features was used in this study to classify patients as healthy or suffering from moderate OSAS. SVM is beneficial as it is easy to learn even with a small dataset, and it can diagnose various flow characteristics as factors while enhancing the feature via the kernel function. As the patient dataset is small, the Monte Carlo cross-validation was used to validate the trained model. Furthermore, to overcome the imbalanced data problem, the oversampling method was applied. The segmented upper-airway results of the high-resolution and low-resolution models present overall average dice coefficients of 0.76±0.041 and 0.74±0.052, respectively. Furthermore, the classification accuracy, sensitivity, specificity, and F1-score of the diagnosis algorithm were 81.5%, 89.3%, 86.2%, and 87.6%, respectively. The convenience and accuracy of sleep apnea diagnosis are improved using deep learning and machine learning. Further, the proposed method can aid clinicians in making appropriate decisions to evaluate the possible applications of OSAS. [Display omitted] [ABSTRACT FROM AUTHOR]

SUMMARY Anisakiasis is an infectious parasitic disease contracted by eating third stage larvae of Anisakis simplex (L3) carried by marine fishes. Human anisakiasis was researched for specific IgG with L3 excretory secretory products (ESP). L3ESP were prepared by daily harvesting of culture supernatant from day 2 to day 5, using two kinds culture media of RPMI-1640 and phosphate buffered saline (PBS). When the sera from persons diagnosed with anisakiasis by means of endoscopy were analyzed using indirect ELISA and Western blot, the sera was classified into four groups depending on specific antigen recognition patterns. In addition, the presence of a new antigen for L3, located at less than 13 kDa (AgLT13) was demonstrated in L3ESP with a modified Western blot condition. The production of AgLT13 was mainly found in L3ESP harvested both on day 2 and day 3, and that in PBS was predominant over that in RPMI-1640. Among those sera, the high reactive sera to L3ESP-day two prepared with phosphate buffer in indirect ELISA recognized AgLT13, and 33% of the low reactive sera did so. These results indicate that the binding pattern of human L3 specific antibody is diverse depending on L3ESP preparations and that AgLT13 demonstrated with a Western blot condition is a specific antigen for L3. [ABSTRACT FROM AUTHOR]

• Simulating IR signatures and flow structure of plume at the rear of solid rocket motor. • Using HTPB (weak afterburning) and NEPE (strong afterburning) propellants. • Confirming the effect of altitude, flight Mach number, and motor size. In this study, radiation signatures of rocket plumes based on HTPB and NEPE propellants are simulated under varying altitudes, flight Mach numbers, and motor size. The flow field of plume is calculated by computational fluid dynamics, and the infrared signature is predicted using a Ludwig model. To verify the numerical method, experiments were conducted using small rocket motors and radiometric FTIR. The acceptable agreement between numerical calculation and the experiment was obtained in 2 – 5 μm wavelength region. The total radiance decreases with increasing altitude whether afterburning exists or not. A decreasing rate in the radiance of the plume with strong afterburning is larger than that of the plume with weak afterburning. The change in total intensity according to altitude depends on the afterburning and is directly affected by the radiating area. As the flight Mach number increases, total radiance, total intensity, and radiating area decrease. The motor size makes radiation intensity increase exponentially; exponent value is from 2.6 to 2.7. As the motor size increases, the effect of altitude increases, while the effect of flight Mach number decreases. [ABSTRACT FROM AUTHOR]

Stacked graphene-oxide (GO) membranes have been reported to have promising potential for desalination. One key issue in the development of such membranes is understanding the atomistic water-permeation mechanism determined by the highly variable nature of GO (including membrane morphology, surface chemistry, osmotic pressure, and surface area). To clearly understand this variability, not only individual but also synergistic effects, i.e., the nonlinear cumulative effects of membrane properties, should be investigated. Hence, this paper explores how lateral and vertical permeation mechanisms differ with changes in the morphology and surface chemistry, either discretely or simultaneously, using both experiments and simulations. Experiments reveal that the GO water-permeation performance is dominated by the heterogeneous structural and chemical nature of GO. To investigate individual and synergistic effects on water dynamics, we performed molecular-dynamics simulations. The synergistic effects were more marked on the lateral permeation mechanisms than on the vertical mechanism in GO membranes. When the membrane nanochannels had a narrow intersheet distance or no gap overlap, the lateral permeation mechanism was found to be completely different owing to the interplay between these properties. Unlabelled Image • Structural and chemical nature dominates GO membrane water-permeation performance. • Effects of structure and chemical composition are explored singly and collectively. • Synergistic effects were more marked on lateral permeation mechanisms. [ABSTRACT FROM AUTHOR]

• Introducing noble method of treating tricuspid regurgitation by membrane insertion. • Tricuspid valve simulated with immersed-boundary lattice Boltzmann method. • Tricuspid valve motion considered by spring network model with volume, area, stretching, bending. • Effect of membrane analyzed by flow dynamics. • Jet area and Reynolds stress used as main parameter for analyzing membrane effect. Tricuspid regurgitation is treated by valve repair or replacement. However, these methods have limitations, and alternative treatment methods are therefore required. In this study, a new method of tricuspid valve treatment using artificial membrane insertion is analyzed. We performed tricuspid valve simulations using an artificial membrane inserted into the right ventricle (RV) or right atrium (RA). We use the lattice Boltzmann method with the immersed boundary condition to model the structural motion of the valve leaflet. The effect of membrane insertion is analyzed in terms of the stress, force, and impulse on the valve leaflet, along with the velocity, pressure, jet volume, and Reynolds stress in the flow field. While the use of either membrane (RA or RV) leads to improved valve closure relative to the use of no membrane, the RV membrane is more effective than the RA membrane in achieving improved valve closure. In addition, a larger membrane area with a shorter distance between the leaflet and membrane increases membrane efficacy. Our results suggest that membrane insertion can form an effective new method for the treatment of tricuspid regurgitation. [ABSTRACT FROM AUTHOR]