Search

With the aim of enhance the designability of burning surface, star and wagon wheel fuel types are applied extensively in hybrid rocket motors. However, mechanism of nozzle ablation in hybrid rocket motors with these complex fuel types is unclear, and this increases the difficulty of predicting ablation laws and thrust. This paper intends to investigate spatial distribution characteristics of nozzle ablation in the hybrid rocket motor with various fuel types. According to the principle that the grain port area and grain length are equal, tube, star, single-port wagon wheel, and multi-port wagon wheel grains are designed. Numerical models for combustion flow and thermochemical erosion are established, and three-dimensional numerical simulations are conducted. A firing test for nozzle erosion is conducted, and hydroxyl-terminated polybutadiene and 95 % hydrogen peroxide are employed. Errors of throat erosion rate and combustion chamber pressure among simulation results and experimental data are 4 % and 4.25 %, respectively. Calculation results demonstrate that the circumferential distributions of nozzle wall temperature and erosion rate show an obvious correlation with fuel types. The maximum throat erosion rates for star, single-port wagon wheel, and multi-port wagon wheel grains occur at the circumferential position of 0° (star slot, spoke slot, and midpoint of outer edge of wheel hole), while the minimum throat erosion rates locate at the circumferential position of 36° (star root, spoke root, and midline of adjacent wheel holes). The circumferential non-uniformity of throat erosion rate of multi-port wagon wheel grain is the highest. When the grain port area and oxidizer mass flow rate are the same, the throat erosion rate of multi-port wagon wheel grain is the highest, followed by the star grain, and the throat erosion rate of single-port wagon wheel grain is the lowest. • Effect of complex fuel types on spatial characteristics of nozzle erosion is studied. • Firing test of carbon-based nozzle erosion is performed to verify numerical models. • Three-dimensional simulations on erosion in hybrid rocket motors are conducted. • Simulation results agree well with test data. • Ablation mechanism of star, single-port, and multi-port wagon wheel grain is revealed. [ABSTRACT FROM AUTHOR]

Background: Rhinoplasty is one of the most challenging plastic surgeries because it lacks a uniform standard for preoperative design or implementation. For a long time, rhinoplasties were done without an accurate consensus of aesthetic design between surgeons and patients before surgery and consequently brought unsatisfactory appearance for patients. In recent years, three-dimensional (3D) simulation has been used to visualize the preoperative design of rhinoplasty, and good results have been achieved. However, it still relied on individual aesthetics and experience. The preoperative design remained a huge challenge for inexperienced surgeons and could be time-consuming to perform manually. Therefore, we adopted artificial intelligence (AI) in this work to provide a new idea for automated and efficient preoperative nasal contour design. Methods: We collected a dataset of 3D facial images from 209 patients. For each patient, both the original face and the manually designed face using 3D simulation software were included. The 3D images were transformed into point clouds, based on which we used the modified FoldingNet model for deep neural network training (by pytorch 1.12). Results: The trained AI model gained the ability to perform aesthetic design automatically and achieved similar results to manual design. We analysed the 1027 facial features captured by the AI model and concluded two of its possible cognitive modes. One is to resemble the human aesthetic considerations while the other is to fulfil the given task in a special way of the machine. Conclusion: We presented the first AI model for automated preoperative 3D simulation of rhinoplasty in this study. It provided a new idea for the automated, individual and efficient preoperative design, which was expected to bring a new paradigm for rhinoplasty and even the whole field of plastic surgery. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

In the study, surface binding energies for pure Ni and Pd metals were calculated using density functional theory. The values obtained were 5.32 and 4.65 eV, respectively, which represents good accuracy for ab initio calculations. The work also included calculations of surface binding energy for different configurations of NiPd alloys with nickel and palladium concentrations of 66, 50, and 33 . Calculations were performed for each type of lattice for both Ni and Pd surface binding energies. Several types of lattices were simulated, and it was found that the average surface binding energies for Ni and Pd are: 5.02 and 4.36 eV, respectively in the alloy with a Ni concentration of 50 ; 4.89 and 4.22 eV, respectively in the alloy with a Ni concentration of 66 ; 5.12 and 4.40 eV, respectively in the alloy with a Ni concentration of 33 . [ABSTRACT FROM AUTHOR]

Purpose: Microwave ablation is a minimally invasive thermal modality for cancer treatment with high survival and low recurrence rates. Despite the unquestionable benefits of microwave ablation, the interaction between the medical instruments and the tissue may cause damage to the healthy tissue around the tumor. Such damages can be removed by clarifying the conditions for their development. In addition to clinical methods, computer simulations have become very effective tools for optimizing microwave ablation performance. Methods: The study was focused on the determination of the optimal input power for complete microwave tumor ablation with an adequate safety margin avoiding injury to the surrounding healthy tissue. In three-dimensional simulations, the liver tumor model was based on a real tumor (1.74 cm × 2.40 cm × 1.43 cm) from the 3D-IRCADb-01 database. Calculations were performed for a 10-slot antenna proven to achieve a higher degree of ablation zone localization than a standard single-slot antenna. The temperature-dependent dielectric and thermal properties of healthy and tumoral liver tissue, blood perfusion, and water content were included in the model. Results: The obtained simulation results revealed that the proper choice of input power ensures that necrotic tissue is mainly located in the tumor with minimal damage to the surrounding healthy tissue. Conclusions: This study may represent a step forward in the planning of individual microwave ablation treatment for each patient. [ABSTRACT FROM AUTHOR]

In recent decades, numerical calculations have often been used to optimise, from a technical and economical perspective, the design of underground works. Using these tools allows efficient and affordable designs to be obtained. Simulation of the tunnelling procedure when using a tunnel-boring machine and in urban areas is a complex soil–structure interaction problem. Here, a three-dimensional (3D) code using finite differences is used. The reference case of this study is Lyon metro line D project in France, where a non-symmetric load is present at the surface due to the presence of a retaining wall. An accurate on-site monitoring system was set up to assess ground movements during the mechanised excavation of twin tunnels. The collected data are used as a reference to show the validity and accuracy of the developed 3D model. Two constitutive models were used to simulate the soil behaviour: plastic hardening (PH) and linear elasticity with perfect plasticity (Mohr–Coulomb shear failure criterion). The Mohr–Coulomb constitutive model shows some drawbacks, which can be eliminated by using PH. The existence of a retaining wall induces a non-symmetric load condition; however, the settlement trough predicted by advanced numerical models shows good agreement with that obtained by monitoring data. [ABSTRACT FROM AUTHOR]

The purpose of this research is to use the methods of data constraints for parametric design and three-dimensional simulation of knitted sweaters to achieve the purpose of enhancing the simulation effect. First, based on the basic plates of knitted sweaters as a reference, the parameters of the curve parts of the plates were constrained, and the constraint relationships were applied to build the parametric design models. After entering the user parameters, the changed plates can be obtained. On this basis, the transformation of flat plates to three-dimensional surfaces was carried out. The triangular grid mapping relationships between two-dimensional plates and three-dimensional surfaces were constructed, and the physical properties were further specified for the mesh particles. When the surface texture parameters of the two-dimensional plane are designed, the three-dimensional surface will change accordingly. In addition, this research put forward the stitching and matching methods of the seams of knitted sweaters. The joint size was equally divided, and the number of coils was converted into the number of triangular mesh. Point-to-point mesh was used to realize the accurate counterpoint fusion of coils. The feasibility of parametric and virtual design methods was verified by taking an example, which provides ideas for the computer-aided design of knitted sweaters and promotes the improvement of production efficiency without wasting raw materials. [ABSTRACT FROM AUTHOR]

Alkaline water electrolyzer (AWE) with KOH aqueous solution as electrolyte is one of the most mature routes for green hydrogen production, in which spherical concave-convex (SCC) shaped flow fields are widely applied. However, while the addition of SCC is known to have significant effects on complex two-phase flow, in particular on the generated hydrogen, detailed understandings of the flow distributions are still lacking. In this paper, we propose to demonstrate the three-dimensional (3D) two-phase flow distributions in SCC shaped flow field for AWE by COMSOL simulation method. First, the typical geometric model is extracted from the practical AWE, based on which the mesh model is constructed; Moreover, the basic 3D simulation results of channel without SCC are evaluated by comparing with the previous experimental studies to demonstrate the model validation; Finally, the 3D flow velocity and hydrogen fraction distributions are carefully illustrated that the SCC shaped structure averages the distribution in the channel effectively and the hydrogen concentration on the electrode surface are reduced, beneficial to the improvement of the electrolysis efficiency, at the outlet of the channel, half of the geometric height (z = 4 mm), the hydrogen fraction in the straight channel is less than 3%, while the hydrogen fraction at the outlet of the SCC channel is about 4%, or even 5% locally. We believe this work can not only provide a guideline for the 3D model establishment for two-phase flow in AWE, but give detailed hydrogen distribution understandings in varied conditions with different current densities. • The 3D simulation model for two-phase flow is extracted and constructed. • The 3D flow velocity and hydrogen fraction distributions are illustrated. • The hydrogen concentration on the electrode surface is reduced by SCC structure. [ABSTRACT FROM AUTHOR]

Methanation is an effective way to efficiently utilize product gas generated from the pyrolysis and gasification of organic solid wastes. To deeply study the heat transfer and mass transfer mechanisms in the reactor, a successful three-dimensional comprehensive model has been established. Multiphase flow behavior and heat transfer mechanisms were investigated under reference working conditions. Temperature is determined by the heat release of the reaction and the heat transfer of the gas-solid flow. The maximum temperature can reach 951 K where the catalyst gathers. In the simulation, changes in the gas inlet velocity and catalyst flow rate were made to explore their effects on CO conversion rate and temperature for optimization purposes. As the inlet gas velocity increases from 2.78 to 4.79 m/s, the CO conversion rate decreases from 81.6% to 72.4%. However, more heat is removed from the reactor, and the temperature rise increases from 78.03 to 113.49 K. When the catalyst flow rate is increased from 7.18 to 17.96 kg/(m²·s), the mass of the catalyst in the reactor is increased from 0.0019 to 0.0042 kg, and the CO conversion rate is increased from 66.8% to 81.5%. However, this increases the maximum temperature in the reactor from 940.0 to 966.4 K. [ABSTRACT FROM AUTHOR]

A mathematical modeling of natural convective energy transport inside partially porous cube with thermally producing element and porous layer has been performed. The viscosity of working medium is considered as temperature dependent with the exponential law. The local thermal non-equilibrium conditions have been used for description of heat transfer inside porous structure. The mathematical model has been formulated employing dimensionless vector potential functions, vorticity vector and temperature. The finite difference technique has been employed to solve the differential equations. The influence of key parameters such as the Nield number, Darcy number, viscosity variation characteristic, thickness of porous zone and time on the fluid flow structure and energy transport inside the cube has been scrutinized. The outcomes have shown that the introduction of a porous zone and an increase in its height lead to more uniform energy removal from the heated unit. In addition, the mean Nusselt number at the energy element surface and the mean temperature within the source are increased with a growing of the interfacial heat transfer coefficient (Nield number) for large permeability of the porous material (Darcy number) while for the intensity of the flow within the chamber the opposite effect can be observed. [ABSTRACT FROM AUTHOR]

A fractal engine simulation (FES) sub-model was integrated into three-dimensional simulations for modeling turbulent combustion for a gasoline direct injection (GDI) engine. The FES model assumes that the effects of turbulence on flame propagation are to wrinkle and stretch the flame, and fractal geometry is used to predict the surface area increase and thus the turbulent burning velocity. Different formulas for the four sequential stages of combustion in SI engines are proposed to account for the changing effects of turbulence throughout the combustion process. However, most prior studies related to the FES model were quasi-dimensional simulations, with few found in multi-dimensional studies, and none under cold start conditions or stratified charges. This paper describes how the model was implemented into multidimensional simulations in CONVERGE CFD, and what the formulas are in the four sequential stages of combustion in SI engines. The capabilities of the FES model for simulating the cold start cases, under the conditions of the dramatically changing engine speed and mixture stratification in a complex engine geometry, are presented in this study. The FES model was able to not only simulate the steady-state cases with constant engine speed, but also predict the in-cylinder pressure traces in all four cylinders for the very first firing cycle with transient engine speed, and gave good agreement with the experimental measurements under these extremely transient conditions. The uncertain maximum fractal dimension was chosen as 2.37 in this research, and a simple linear correlation with engine speed was used to obtain the coefficient used in calculating the kernel formation time which controls the so-called combustion or ignition delay. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the relationship between acetabular width, three-dimensional (3D) simulation, and surgical results in total hip arthroplasty patients who have developmental dysplasia of the hip (DDH). This retrospective study included 216 DDH cases. Inner and outer acetabular width (OAW) was measured at the plane passing through the center of acetabular fossa. 3D simulation and 2D standard templating were performed. The actual cup size and the use of augments during surgery were recorded. Association among the indices and their distribution in different types of DDH were analyzed. A difference of 13 to 14 millimeters (mm) was found between the inner acetabular width and actual cup size used in type II, III, and IV cases, while the difference was 0.2 to 3.6 mm for OAW. The accuracy of 2D templating and 3D simulation in predicting cup size was comparable in Crowe type I (86.5 versus 76%, P =.075), type II (72.7 versus 51.5%, P =.127), and type III (93.3 versus 66.7%, P =.169). The 3D simulation was significantly more accurate in Crowe type IV (89.1% versus 60.9%, P =.001). Augments and bone grafts were significantly more commonly used in type II (25%) than in the other types (0 to 6.5%). OAW more accurately predicted actual cup size than inner acetabular width. The supero-lateral acetabular bone defects in type II cases require additional attention. Compared with 2D templating, 3D simulation is more accurate in predicting actual cup size in dysplastic hips with severe deformity and may be recommended in these selected cases, especially for Crowe IV patients. [ABSTRACT FROM AUTHOR]

On the basis of experiments at atmospheric pressure, a three-dimensional simulation study of the spray pattern and breakup mode of gas-centered swirl coaxial (GCSC) injector was conducted with the RNG k-ε model. The gas-liquid interface was captured by the adaptive mesh refinement (AMR) technique, coupled level-set and volume of fluid (CLSVOF) method. The results demonstrated that when the liquid mass flow rate (ṁ1) is constant, the ejection action of the central airflow is enhanced along with the gas mass flow rate (ṁg). The internal and external pressure difference of the liquid film increases and the spray angle decreases. Meanwhile, the flow characteristics were analyzed. When ṁg is constant, the radial velocity and tangential velocity of the liquid film at the injector outlet increase with ṁ1, which may result in the increase of the spray angle. According to the gas-liquid mass flow rate (GLR), the breakup modes of spray are divided into the perforation breakup, bubble breakup and pneumatic breakup.

Organic solid waste (OSW) contains many renewable materials. The pyrolysis and gasification of OSW can realize resource utilization, and its products can be used for methanation reaction to produce synthetic natural gas in the specific reactor. In order to understand the dynamic characteristics of the reactor, a three-dimensional numerical model has been established by the method of Computational Fluid Dynamics (CFD). Along the height of the reactor, the particle distribution in the bed becomes thinner and the mean solid volume fraction decreases from 4.18% to 0.37%. Meanwhile, the pressure fluctuation range decreased from 398.76 Pa at the entrance to a much lower value of 74.47 Pa at the exit. In this simulation, three parameters of gas inlet velocity, operating temperature and solid particle diameter are changed to explore their influences on gas-solid multiphase flow. The results show that gas velocity has a great influence on particle distribution. When the gas inlet velocity decreases from 6.51 to 1.98 m/s, the minimum height that particles can reach decreases from 169 to 100 mm. Additionally, as the operating temperature increases, the particle holdup inside the reactor changes from 0.843% to 0.700%. This indicates that the particle residence time reduces, which is not conducive to the follow-up reaction. Moreover, with the increase of particle size, the fluctuation range of the pressure at the bottom of the reactor increases, and its standard deviation increases from 55.34 to 1266.37 Pa. [ABSTRACT FROM AUTHOR]

Featured Application: The methodology proposed in this paper studies the mobility of a multi-loop spherical mechanism with a spherical slider containing a spherical prismatic pair. By analyzing the motion of each closed kinematic chain that the mechanism consists of, not only can the proposed methodology thoroughly and accurately identify the mechanism's singularity configurations, but the method can also demonstrate the mechanism's range of motion. Therefore, the proposed method ultimately identifies the mechanism's motion continuity and smoothness, which are two of the most essential characteristics a multi-loop spherical mechanism possesses. Hence, the proposed methodology can help mechanism designers create multi-loop mechanisms with spherical sliders without motion deficiencies by avoiding the mechanisms' singularity configurations. Multi-loop spherical mechanisms are extremely beneficial for creating versatile mechanical devices, including robotic joints and surgical tools, since multi-loop spherical mechanisms possess unique capabilities to operate in spatial situations with relatively simple movement. Nevertheless, the research on multi-loop spherical mechanisms with spherical sliders containing spherical prismatic pairs is lacking. Therefore, the main innovation of this paper is to propose the Stephenson-III two-loop spherical mechanism that possesses a spherical slider containing a spherical prismatic pair and to analyze the proposed spherical mechanism's motion characteristics. An algebraic approach was employed to obtain the branch graphs of the proposed spherical mechanism with a spherical slider. The branch graphs were categorized into two types, according to whether branch points existed. With the algebraic approach, loop equations of the two spherical kinematic chains inside the proposed spherical mechanism were established to identify the input–output curves and singularity curves, with which the branch graphs were obtained. With the branch graphs, the joint rotation spaces (JRSs) of the proposed mechanism were recognized and so were the dead center positions, branches, sub-branches, and branch points. The results from the mathematical analysis were simulated and verified by three-dimensional (3D) models of the proposed spherical mechanism. The analytical results demonstrate that the spherical prismatic pair diversifies the motion of the proposed spherical mechanism by producing rotational sliding movement, which can cover the entire circumference of a specific greater circle on the proposed mechanism's sphere. [ABSTRACT FROM AUTHOR]

This study proposes a method for 3D modeling of weft knitted fabric and simulating its deformation behavior. A geometric model of the fabric was established using a loop-mesh unit, and the surface of the yarn was calculated using a reference frame. The patterns of the fabrics were represented by bitmap images. To simulate the deformation behavior of the fabric, a physical model was built based on a dynamic spline that included stretching and bending of the yarn. To simplify the collisions between continuous yarns, collisions were detected using a discrete sphere-spring model. The Euler-Lagrange theorem was introduced to achieve the energy balance of the system, and a stable shape was obtained by solving the Euler-Lagrange equation explicitly according to the convergence conditions. Rendering and deformation of the model were implemented using a simulator program via C++ and OpenGL. The simulation displayed the 3D appearance of the weft knitted fabric. The deformed shapes of fabrics were accurately predicted by the proposed method. [ABSTRACT FROM AUTHOR]

Objectives: Patient satisfaction is of paramount importance in breast augmentation surgery. One of the most important determinants of the post-operative outcome is the implant volume. Conventionally, patients are fitted with different-sized implants under their bra to give them an idea of the post-operative result. However, it is cumbersome, and the patient is not able to visualize the final appearance of her breast. With the advent of three-dimensional (3D) simulations, this technique is increasingly being employed in pre-operative counseling sessions to aid the patient in choosing the right implant size for herself. We wished to study the usefulness of 3D simulation as a clinical aid in pre-operative counseling of breast augmentation patients. Materials and Methods: In this study, we asked a set of three questions to the patients who chose their breast implant size based on 3D simulation to understand their views on the utility of this technique. Results: The majority (85-90%) of the respondents found 3D simulation to be very helpful in choosing the implant and would strongly recommend it to their peers. They also found the post-operative results to be very concordant with the pre-operative simulated image. Conclusion: 3D simulation is a useful aid in choosing the implants for breast augmentation and helps in involving the patient in the decision-making process, resulting in higher satisfaction. [ABSTRACT FROM AUTHOR]

Increasing rain levels can easily destabilize and destroy particulate matter in mountainous areas, which can cause natural disasters, such as debris flow and landslides. Constitutive equations and numerical simulation are the theoretical bases for understanding the behavior of these disasters. Thus, this study aimed to investigate the impact of the debris flow and its entrainment behavior on gully bed sediments. We adopted a coupled analysis method based on elastic–plastic constitutive equations by considering the elasto-plasticity of slurry and the elastic characteristics of debris materials. The coupled method consisted of smooth particle hydrodynamic (SPH), discrete element method (DEM), and finite element method (FEM) (SPH–DEM–FEM). SPH particles represented fluid, DEM particles denoted solid immersed in fluid, and FEM elements represented the terrain and structures. The coupling analysis model was used to simulate the coupling contact of solid, liquid, and structures and to describe the entrainment behavior between solid and liquid phases. The model feasibility was verified by comparing the basic simulation results with experimental values of the dam break model and the rotating cylindrical tank model. The coupled model was then combined with the data management and modeling of geographic information system to simulate the 2010 Yohutagawa debris flow event. Finally, we explored the influence of debris shape-related parameters on the debris flow erosion entrainment process.

This paper presents a reliable algorithm for solving the inverse kinematic (IK) problem of continuum robots. Admittedly, there are an infinite number of configurations to get the robot's end point (EP) pose. Therefore, the proposed algorithm introduces a new solution that helps narrow the infinite number of the IK solutions down to a finite one by taking into account the first (n - 1) sections' sets of reachable EP poses, which are selected and created one-by-one from the first to (n - 1) th section, in which the Particle Swarm Optimization method is adopted to randomly pick up the first IK solution. However, a specific criterion has been accorded to select the appropriate IK solution (i.e., redundancy resolution) among the existing varieties that perfectly fits within the targeted trajectory. Furthermore, numerical experiments are performed on a Cable-Driven Continuum Robot for tracking a trajectory in a free and confined environment, pointing up on IK, multiple IK solutions and redundancy resolution. The obtained results demonstrated that the proposed algorithm is computationally accurate and efficient in obtaining all-inclusive IK solutions and redundancy resolution of continuum robots in comparison to previously proposed approaches. It is noteworthy to say that the proposed algorithm can be applied to any kind of continuum robots and most importantly regardless of its number of sections, which makes the developed algorithm a sovereign remedy for the IK problem of these robots. [ABSTRACT FROM AUTHOR]

Some features of the electron exchange between ions and a metal surface, which are due to its atomic structure, are numerically investigated. Simulation is based on three-dimensional implementation of the wave-packet propagation method. The studied system consists of an Al(110) metal surface and an excited hydrogen atom with an electron in the p state, which does not have spherical symmetry. When considering the static model problem, it is shown that the electron exchange is more efficient if the symmetry axis of the p orbital is oriented perpendicular to the metal surface rather than if it is parallel to it. Also, analysis of the obtained data shows that the time dependence of the atomic energy level population has an exponential dip. Consideration of the "dynamic" problem showed that, for an excited hydrogen atom moving along a metal surface, the electron exchange does not depend on the p-orbital orientation with respect to the direction of atom motion. For the p orbitals, the symmetry axes of which are directed parallel to the metal surface, the study of the dynamics of electron-charge transfer with the metal surface makes it possible to observe separation of the electron density passing to the surface into two parts, which diverge relative to the p-orbital symmetry plane. [ABSTRACT FROM AUTHOR]

BackgroundSurgical intervention is necessary for resolving the symptoms of the spinal cord and nerve compression caused by symptomatic metastatic epidural spinal cord compression. However, surgeons are constantly seeking ways to improve surgical efficiency and safety. This study aims to evaluate the efficacy of 3D simulation/printing-assisted surgery for symptomatic metastatic epidural spinal cord compression of the posterior column.MethodsWe retrospectively analyzed the clinical data of patients who underwent surgical treatment for symptomatic metastatic epidural spinal cord compression of the posterior column in our hospital from January 2015 to January 2020. The simulated group underwent a 3D digital simulation of the lesion area using imaging data before surgery. Twelve patients in the simulated group also received 3D printing, while the direct surgery group did not receive any 3D simulation or printing. All patients were followed up for at least 2 years. We collected clinical data, including operation time, intraoperative blood loss, pedicle screw adjustment rate, intraoperative fluoroscopy times, the incidence of dural injury and cerebrospinal fluid leakage, VAS score, postoperative neurological function improvement, and tumor recurrence. Statistical analysis was performed using SPSS23.0, and P

Mandaue is a crucial city in Cebu island, Philippines as it links other large metropolises and is highly industrialized. The occurrence of urban heat island (UHI) in Mandaue was already confirmed by a previous study. In this paper, we aim to determine how UHI in Mandaue could be improved by mitigations including increasing vegetation, adding open spaces, employing green roofs and/or a combination thereof. ENVI-met software was utilized to simulate two study sites: M. C. Briones street and the planned urban development (PUD). To reduce computing load, M. C. Briones street was further divided into 2 subareas and PUD into 4 subareas. Results of the simulation indicate that addition of more urban spaces and trees could decrease air temperature by 0.2 ​°C on average while green roof could decrease air temperature by an average range of 0.2 ​°C–0.4 ​°C. When a combination of trees, grasses and green roof is used, air temperature could be decreased by an average range of 0.1 ​°C–0.3 ​°C. Despite these mitigations, thermal comfort index in Mandaue would still be greater than 26 ​°C which means that majority of the people would feel uncomfortable. On the other hand, addition of more urban spaces and trees could decrease surface temperature by an average range of 0.5 ​°C–0.8 ​°C while conversion of building roofs into green roofs would have no effect. When a combination of vegetation and green roof is employed, surface temperature could be decreased by an average range of 0.4 ​°C–1.1 ​°C.

• The explicit correction scheme, along with with the simplified Dirac function coefficient, has been developed to effectively addresses the challenge of efficiently applying moving boundary conditions through immersed boundary method in three-dimensional simulations. • The employed velocity correction and surface flux correction, based on the immersed boundary method, accurately capture the moving contact lines between the moving curved surface structure and the interface of multiphase fluids. • Numerical simulations using the proposed method for the interface penetration and the free water exit of a hollow sphere are carried out, highlighting the promising potential of the proposed method in applications. In the realm of numerical algorithms for investigating interactions between multiphase fluids and structure, the accurate computation of moving contact lines (MCLs) dynamics and the substantial computational resource demands bring challenges in three-dimensional simulations. In this study, an improved diffuse interface-immersed boundary method is proposed to efficiently investigate three-dimensional multiphase fluids–structure interactions. The present work commences with the development of the explicit correction scheme and the simplified Dirac function coefficient, designed to efficiently implement the immersed boundary technique. To validate the effectiveness and accuracy of the proposed method, the simulations of water entry and exit for a half-buoyant sphere are carried out, which conclusively demonstrate that the proposed method offers significant advantages in terms of both efficiency and accuracy, faithfully capturing the dynamic response of solid structures and the substantial deformation of free surfaces at the three-dimensional scale. Additionally, a comparative analysis of the results obtained using the proposed method for the free water exit of a hollow sphere against previous experimental data is conducted, highlighting the promising potential of the proposed method for applications. [ABSTRACT FROM AUTHOR]

• We developed a FLUS-3D model for the simulation of real-world 3D urban dynamics. • Horizontal and vertical information can be concurrently updated in each iteration. • The FLUS-3D model outperforms existing models in comparative experiments. • The model was applied to large-scale future 3D urban simulation under SSPs. Existing research on urban dynamic simulations has primarily focused on horizontal aspects, whereas vertical changes have remained relatively unexplored. Although a few preliminary studies have attempted to simulate three-dimensional (3D) urban dynamics, these have generally amounted to rudimentary amalgamations of horizontal urban expansion simulation and vertical height estimation. In this study, we enhanced our original Future Land Use Simulation (FLUS) model into a 3D version (FLUS-3D) to simulate the continuous 3D dynamics of real-world urban development. A distinctive characteristic of the proposed model is its ability to concurrently update 3D information of the developed land grids during the simulation process. The FLUS-3D model was assessed via simulations across three metropolitan regions in China: the Beijing–Tianjin–Hebei, Yangtze River Delta, and Pearl River Delta regions. Satisfactory simulation performances were found across all regions, with Figure of Merit values ranging 0.21–0.35 for horizontal expansion, overall accuracy values of 83 % for the refinement of urban functional types, and root mean squared error values of 5–7 m for built-up height simulations. Comparative experiments further demonstrated a significant outperformance of the FLUS-3D model compared to that of existing models. Subsequently, the proposed model was applied to simulate the future evolution of 3D urban dynamics until 2030 under the Shared Socioeconomic Pathways (SSPs). The simulation results effectively illustrated the influence of each SSPs on 3D urban development. Given that 3D urban structures are fundamental parameters in urban climate modeling, the proposed model can potentially be used in urban-related studies climate change mitigation to achieve future urban sustainability. [ABSTRACT FROM AUTHOR]

The dismantling and recycling of junction boxes, which is an important part of the photovoltaic module recycling process, was tested and designed scientifically. The equipment framework was built by three-dimensional simulation, and then the design of dismantling and recycling equipment for junction boxes of waste crystal silicon photovoltaic modules was completed through the experimental test and data analysis. The experimental results show that the initial idea of the dismantling scheme is correct, and the structure is feasible. However, some problems were not considered. This study provides reliable data support for the subsequent equipment development and ensures the smooth development of the subsequent design work. [ABSTRACT FROM AUTHOR]

Multi-loop spherical mechanisms are extremely beneficial for creating versatile mechanical devices, including robotic joints and surgical tools, since multi-loop spherical mechanisms possess unique capabilities to operate in spatial situations with relatively simple movement. Nevertheless, the research on multi-loop spherical mechanisms with spherical sliders containing spherical prismatic pairs is lacking. Therefore, the main innovation of this paper is to propose the Stephenson-III two-loop spherical mechanism that possesses a spherical slider containing a spherical prismatic pair and to analyze the proposed spherical mechanism’s motion characteristics. An algebraic approach was employed to obtain the branch graphs of the proposed spherical mechanism with a spherical slider. The branch graphs were categorized into two types, according to whether branch points existed. With the algebraic approach, loop equations of the two spherical kinematic chains inside the proposed spherical mechanism were established to identify the input–output curves and singularity curves, with which the branch graphs were obtained. With the branch graphs, the joint rotation spaces (JRSs) of the proposed mechanism were recognized and so were the dead center positions, branches, sub-branches, and branch points. The results from the mathematical analysis were simulated and verified by three-dimensional (3D) models of the proposed spherical mechanism. The analytical results demonstrate that the spherical prismatic pair diversifies the motion of the proposed spherical mechanism by producing rotational sliding movement, which can cover the entire circumference of a specific greater circle on the proposed mechanism’s sphere.

In this paper, a three‐dimensional (3D) numerical study of thermal convection and acoustic waves is presented using a hybrid method. This method consists of two computational approaches: the lattice Boltzmann method (LBM) with multiple relaxation times for the study of the fluid behavior and the finite difference method (FDM) for the description of the thermal exchange. The two approaches have been validated by studying two benchmark problems reported in the literature. The LBM was validated by simulating the flow induced by a lid‐driven cavity. The FDM was checked by simulating natural convection in a differentially heated cubic cavity filled with air. After this validation, the main focus was on the study of enhancement of the heat transfer in a 3D cavity using a vibrating acoustic source. The numerical study is performed for different values of the wave amplitude, the Rayleigh number (Ra ${Ra}$), and the sound source size. It shows that the heat transfer is significantly improved for a low Ra ${Ra}$. However, for high Ra ${Ra}$ values, natural convection cannot be neglected in front of forced convection. The transfer is also influenced by the variation of the source size. This allows obtaining the optimal size corresponding to the maximum heat exchange. [ABSTRACT FROM AUTHOR]

The current study aimed at evaluating the prospects of a three-dimensional gas power plant (GPP) simulation in an immersive virtual reality (IVR) environment for fire emergency preparedness and response (EPR). To achieve this aim, the study assessed the possibility of safety situational awareness, evacuation drills and hazard mitigation exercises during a fire emergency simulation scenario. The study likewise evaluated the safety and ergonomics of the environment while addressing this aim. We employed the virtual reality accident causation model (VR-ACM) for the assessment with 54 participants individually in IVR. Participants were grouped into two according to whether they had work experience in engineering or not. The obtained results suggested that IVR can be realistic and safe, with the potential for presenting hazardous scenarios necessary for fire EPR. Furthermore, the results indicated that there were no statistically significant differences in the perceptions of both groups regarding the prospects of IVR towards EPR. [ABSTRACT FROM AUTHOR]

Abstract Background Bochdalek hernia is a common congenital diaphragmatic defect that usually manifests with cardiopulmonary insufficiency in neonates. It is very rare in adults, and symptomatic cases are mostly left-sided. Diaphragmatic defects generally warrant immediate surgical intervention to reduce the risk of incarceration or strangulation of the displaced viscera. Case presentation A 47-year-old woman presented with dyspnea on exertion. Computed tomography revealed that a large part of the intestinal loop with superior mesenteric vessels and the right kidney were displaced into the right thoracic cavity. Preoperative three-dimensional (3D) simulation software visualized detailed anatomy of displaced viscera and the precise location and size of the diaphragmatic defect. She underwent elective surgery after concomitant pulmonary hypertension was stabilized preoperatively. The laparotomic approach was adopted. Malformation of the liver and the presence of intestinal malrotation were confirmed during the operation. The distal part of the duodenum, jejunum, ileum, colon, and right kidney were reduced into the abdominal cavity consecutively. A large-sized oval defect was closed with monofilament polypropylene mesh. No complications occurred postoperatively. Conclusion Symptomatic right-sided Bochdalek hernia in adults is exceedingly rare and is frequently accompanied by various visceral anomalies. Accurate diagnosis and appropriate surgical repair are crucial to prevent possible incarceration or strangulation. The preoperative 3D simulation provided comprehensive information on anatomy and concomitant anomalies and helped surgeons plan the operation meticulously and perform procedures safely.

• Water distribution in the in/through-plane directions is quantitatively evaluated. • Non-uniform water distribution and cathode water starvation cause poor performance. • 4-fold increase in conductivity only results in a 62 % increase in cell performance. • High membrane water diffusivity and low EOD coefficient promote cell water balance. • Water conversion rate has a negligible effect on AEMFC if it is lower than 1 s−1. Effective water management is crucial in anion-exchange membrane fuel cells (AEMFCs) due to water's dual role as a reactant during alkaline oxygen reduction and a product of alkaline hydroxide oxidation. Meanwhile, both hydroxide conduction and water transport in polymer electrolytes are highly dependent on the hydration level. Therefore, a three-dimensional multi-physics model is developed to investigate the critical role of ionic and water transport parameters of the electrolyte on AEMFC performance. Additionally, detailed water distribution analysis is used to reveal its fundamental mechanism. The results reveal that extremely inhomogeneous water distribution and cathode water starvation are the main causes of the poor cell performance. Moreover, increasing membrane water diffusivity, water conversion, and decreasing the electro-osmotic drag coefficient all contribute to better cell performance through improved water balance and cathode water supply. Among these, cell performance is most sensitive to membrane water diffusivity, with a 40 % increase in peak power density when it is increased from 10−10 m2 s−1 to 10−9 m2 s−1. Although high ionic conductivity improves cell performance by directly reducing ohmic impedance, it also results in a more inhomogeneous distribution of water in the whole cell, so that a four-fold increase in ionic conductivity only yields a 62 % increase in peak power density. [ABSTRACT FROM AUTHOR]

Abstract Background In hepatectomy, the preservation of portal perfusion and venous drainage in the remnant liver is important for securing postoperative hepatic function. Right hepatectomy is generally indicated when a hepatic tumor involves the right hepatic vein (RHV). However, if a sizable inferior RHV (IRHV) exists, hepatectomy with preservation of the IRHV territory may be another option. In this case, we verified the clinical feasibility of anatomical bisegmentectomy 7 and 8 with RHV ligation, averting the right hepatic parenchyma from venous congestion, utilizing the presence of the IRHV. Case presentation A 70-year-old man was presented with a large hepatic tumor infiltrating the RHV on computed tomography during a medical checkup. The patient was diagnosed with hepatocellular carcinoma (HCC), T2N0M0, stage III. Right hepatectomy was first considered, but multi-detector computed tomography (MDCT) also revealed a large IRHV draining almost all of segments 5 and 6, suggesting that IRHV-preserving liver resection may be another option. The calculated future remnant liver volumes were 382 mL (26.1% of the total volume) after right hepatectomy and 755 mL (51.7% of the total volume) after anatomical bisegmentectomy 7 and 8; therefore, we scheduled IRHV-preserving anatomical bisegmentectomy 7 and 8 considering the prevention of postoperative liver failure and increased chance of performing repeat resections in cases of recurrence. Preoperative three-dimensional simulation using MDCT clearly revealed the portal perfusion area and venous drainage territories by the RHV and IRHV. There was an issue with invisibility of the anatomical resection line of segments 7 and 8, which was completely dissolved by intraoperative ultrasonography using Sonazoid and the portal dye injection technique with counter staining. The postoperative course in the patient was uneventful, without recurrence of HCC, for 30 months after hepatectomy. Conclusions IRHV-preserving anatomical bisegmentectomy 7 and 8 is a safe and feasible procedure utilizing the three-dimensional simulation of the portal perfusion area and venous drainage territories and the portal dye injection technique.

In recent years, research on road piezoelectric energy harvesters (RPEH) has made great progress in the field of road vibration energy harvesting. However, the research on the packaging structure and embedding method of RPEH is not comprehensive. In this paper, a new type of transducer unit structure is developed, which can improve the electrical energy output compared with the drum piezoelectric transducer, and its waterproof performance of the transducer unit is tested under different water depth and duration. Then, a new RPEH package structure is made, and the output performance is compared with the three commonly used package structures in the current research, and the field construction of RPEH with different embedding methods is carried out on the actual road to evaluate the electrical energy output capacity of RPEH under different embedding methods, and the best construction method of RPEH is summarized through durability test. Finally, the three-dimensional simulation model of RPEH with different construction methods is established, and the stress and voltage are analyzed by finite element method to verify the best embedding method. The test results show that the piezoelectric output efficiency of the new transducer unit is increased by 38.9 %, and it still has good electrical energy output after 24 h immersion at a depth of 1.5 m, and its waterproof level reaches IPX8. Under larger excitation frequency and load, the indoor output of RPEH in the new package structure has better output performance in indoor test. The bolt-spring package is used to apply pre-pressure to RPEH, and the output efficiency of RPEH is improved. When the excitation conditions are 10 kN, 10 Hz, the output power is increased by 11.1 %, 127.3 % and 247.4 % compared with the other three package structures. The maximum power of RPEH is 3.41 W by placing concrete on the bottom surface of RPEH sponge washer and using asphalt as the pavement layer to ensure the durability of piezoelectric pavement. The finite element analysis illustrates the strain and voltage variation of piezoelectric pavement with different embedment modes, and the simulation results are consistent with the test results. The research results provide an important basis for the design of RPEH packaging structure and embedding method in road piezoelectric engineering. [ABSTRACT FROM AUTHOR]

We investigated the effects of atherosclerosis in the carotid region on cerebral haemodynamics. A total of 15 stenosis cases following NASCET criteria were modelled using patient-specific medical image data and an open-source package, SimVascular. The formulation adopted the stabilised Petrov–Galerkin scheme with Newtonian and incompressible assumptions. The boundary conditions employed pulsatile inflow and three-element lumped Windkessel outlet conditions with a rigid wall assumption. We present transitions in the represented CoW during stenosis progression using three-dimensional aortic-cerebral vasculature for the first time. This was driven by the conserved total cerebral blood flow to 50% carotid stenosis (CS) (P-value, P > 0.05), which deteriorated during subsequent stages of CS (P < 0.01), and the effective collateral capability of the communicating arteries (CoAs) activated from a degree of 75% and above (P < 0.0001). The prevalence of ‘complete’ CoW peaked at 50% CS and then declined. Despite the collateral flow, the ipsilateral hemispheric perfusion was moderately reduced (P < 0.01), and the contralateral perfusion was conserved (P > 0.05), revealing the ineffectiveness of collateral capability of CoW at the extreme stages of CS. We identified bulk cerebral auto-regulation effects of the conventional Windkessel model, demonstrating accurate flow reduction in the stenosed artery.

Ao Kung Krabaen Lagoon (AKBL) is a small and shallow coastal lagoon situated in the eastern part of Thailand. It is an important "Blue Carbon" ecosystem of this region. However, water quality of the lagoon has drastically deteriorated in recent years. To counteract the problem, a comprehensive understanding of water circulation within the lagoon and exchange with the outer sea is needed. In this study, seasonal field observations were made and then applied in three-dimensional hydrodynamic simulations using Delft3D-FLOW. Results indicate that water properties, water circulation and water exchange differ notably by season. During the southwest (SW) monsoon (July-September), circulation is at its strongest, and there are strong double-gyre circulations. This results in enhancing exchange with the sea, hence significantly reducing flushing time. The flushing time during the SW monsoon is approximately three days. During the transition period (April-May) between the northeast monsoon and the SW monsoon, sluggish circulation dominates the lagoon. The flushing time increases to around 10 days, which is the annual maximum. Water circulation within the lagoon is mostly in two-dimensional patterns owing to its shallowness, even though water exchange occurs in three dimensions. This study also demonstrates that the tropical coastal lagoons scattered around the world should be considered three-dimensionally and with attention to varying water density both inside and outside the lagoon to properly model their hydrodynamics and exchange with the outer sea. [ABSTRACT FROM AUTHOR]

Electrostatic adsorption dust removal can effectively improve the dust removal effect of inhalable particles. The grid layout in the flue gas affects the dust removal efficiency and channel pressure drop, and increases the power loss of the fan. In this paper, according to the velocity of flue gas and the concentration of particulate matter in flue gas, combined with the principle of electrostatic adsorption, a three-dimensional module including the main components of adsorption and dust removal was established. The distribution of pressure drop in the flue gas channel caused by the adsorption components with grid layout was simulated and analyzed, which provided a reference for the reasonable layout of dust adsorption components. The simulation results show that the smaller the component diameter, the smaller the pressure difference caused by the same number of components, and the smaller the longitudinal spacing of components. [ABSTRACT FROM AUTHOR]

We investigated the effects of atherosclerosis in the carotid region on cerebral haemodynamics. A total of 15 stenosis cases following NASCET criteria were modelled using patient-specific medical image data and an open-source package, SimVascular. The formulation adopted the stabilised Petrov–Galerkin scheme with Newtonian and incompressible assumptions. The boundary conditions employed pulsatile inflow and three-element lumped Windkessel outlet conditions with a rigid wall assumption. We present transitions in the represented CoW during stenosis progression using three-dimensional aortic-cerebral vasculature for the first time. This was driven by the conserved total cerebral blood flow to 50% carotid stenosis (CS) (P-value, P > 0.05), which deteriorated during subsequent stages of CS (P < 0.01), and the effective collateral capability of the communicating arteries (CoAs) activated from a degree of 75% and above (P < 0.0001). The prevalence of 'complete' CoW peaked at 50% CS and then declined. Despite the collateral flow, the ipsilateral hemispheric perfusion was moderately reduced (P < 0.01), and the contralateral perfusion was conserved (P > 0.05), revealing the ineffectiveness of collateral capability of CoW at the extreme stages of CS. We identified bulk cerebral auto-regulation effects of the conventional Windkessel model, demonstrating accurate flow reduction in the stenosed artery. [ABSTRACT FROM AUTHOR]

To solve the problems of autonomous underwater vehicle ( AUV) with high test cost, requiring ideal simulation environment for the application of underwater robots and robot verification and difficult modeling of simulation environment, the MOOS software system was used to perform navigation, communication and three-dimensional simulation of the AUV navigation system. The communication methods, the software architecture, the data collection methods and the sensor data types of the MOOS software system were configured and simulated. Based on the perspectives of mechanism, the data subscription and publication and the data analysis and processing, the MOOS software system was analyzed and verified. The results show that the MOOS system can generate relevant environmental sensor data according to the preset trajectory of AUV, which can effectively realize multi-source information fusion and navigation pose calculation. [ABSTRACT FROM AUTHOR]

Abstract Background Revision total hip arthroplasty (THA) with large acetabular defect remains a challenge. Though trabecular metal (TM) cup and augments have been introduced in defect reconstruction with good result, the accurate positioning of implant is important to avoid complications. Therefore, we aimed to evaluate the usefulness of three-dimensional (3D) simulation and 3D model in assisting implant positioning during complex revision THA. Methods Sixteen patients (18 hips) who underwent revision THA with a Paprosky type III acetabular defect were analyzed retrospectively. Placement of acetabular cup and TM augments was simulated with 3D simulation software and 3D model preoperatively. Cup anteversion, abduction angle, and hip center were measured in each case preoperatively and postoperatively. Primary outcome was the percentage of outliers according to Lewinnek safe zone and Harris hip score (HHS). Secondary outcome was the correlation between the 3D planned and the postoperative value. Results The percentage of outliers was significantly corrected from 77.78% (14/18) preoperatively to 38.88% (7/18) postoperatively (p = 0.04). There was a significant correlation between mean planned cup anteversion and postoperative value (13.39 vs 11.99, r = 0.894; p < 0.001). There was a significant correlation between mean planned abduction and postoperative value (42.67 vs 44.91, r = 0.921, p < 0.001). The number of planned and used augments was the same in all the cases. In 15 cases (83.33%), the size of planned and used TM augments was the same. The HHS was significantly improved at final follow-up (80.94 vs 27.50, p < 0.001). No cases presented dislocation or radiological signs of loosening. Conclusion Preoperative 3D simulation and model were considered the useful method to assist implant positioning in revision THA with complex acetabular defect, with moderate to high accuracy and satisfied clinical outcome.

Background: Preoperative three-dimensional (3D) lung reconstructions can reduce intraoperative blood loss, conversion rate, and operation duration. These 3D reconstructions are predominantly provided by commercial expensive products, hence we aimed to assess the usability and performance of preoperative 3D lung reconstructions created with open-source software., Methods: Patients were invited to participate in this prospective pilot study if they were planned for uniportal video-assisted thoracoscopic surgery (VATS) lobectomy or segmentectomy between January and February 2023. Participants were excluded if a two-dimensional (2D) late-arterial-phase computed tomography (CT) scan contained motion artifacts, another surgical procedure was performed, or the surgery was canceled. After informed consent was obtained, 3D lung reconstructions were constructed using open-source 3D Slicer software. The system usability score (SUS) questionnaire assessed the usability of these reconstructions, whilst performance was evaluated based on anatomical validity compared to prior 2D CT assessment as well as operative findings. Descriptive statistics were reported., Results: Thirteen patients were included, of whom one underwent a segmentectomy. Eighty-three percent of the 3D lung reconstructions scored above average (SUS >68). Compared to 2D CT scans, 38% of lung nodule segmental locations were detected more accurately through 3D lung reconstructions. Furthermore, 3D lung reconstructions revealed anatomical variations in 62%, which were not recognized on 2D CT scans, and provided surgeons with insights that would change the procedure and/or transection planes in 62%. One 3D lung reconstruction failed to demonstrate an intraoperative recognized segmental pulmonary artery (A6) branch., Conclusions: Three-dimensional lung reconstructions created with open-source software were usable and effective for uniportal VATS anatomical resections., Trial Registration: ClinicalTrials.gov/NCT06132607., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tlcr.amegroups.com/article/view/10.21037/tlcr-24-134/coif). K.W.E.H., Y.L.J.V. and E.R.d.L. received consulting fees from Johnson & Johnson for education in uniportal VATS lobectomy. K.W.E.H. is a board member of the Dutch Federation of Medical Specialists. The other authors have no conflicts of interest to declare., (2024 Translational Lung Cancer Research. All rights reserved.)

Flow mal-distribution in the shell side of the gas-cooled conventional reactor (CR) in the mega methanol plant is responsible for producing gas condensate in the catalytic zone. This phenomenon leads to catalyst agglomeration and efficiency reduction in the reactor. In this study, two novel and viable strategies, possible to be implemented in working reactors, are introduced to prevent condensation. In the first strategy, co-current mode (CCM), the reactant flow changes from counter-current into the co-current. In this regard, the feed inlet is replaced from the bottom of the reactor into the top. In the second strategy, changed-bed mode (CBM), the catalyst particles at the last two meters of the reactor are replaced with non-reactive ceramic balls. The results for three-dimensional computational fluid dynamics (CFD) in CR have been validated against previous study and industrial data, indicating close agreement. The main advantage of CCM and CBM is that the sudden temperature drop fails to occur at the end of the reactor. Consequently, the higher temperature of the products prevents water and methanol condensation. In addition, the CCM leads to a milder temperature profile throughout the shell side, which increases catalyst durability. [ABSTRACT FROM AUTHOR]

Reverse shoulder arthroplasty (RSA) is a viable option for posteriorly-eroded B2 glenoids. But little is known in this setting about the effect of baseplate version on impingement on the scapular neck, which affects the risk of notching, the risk of impingement-related instability, and the passive range of motion (ROM). Correcting retroversion with eccentric reaming leads to medialization to achieve full support of the baseplate, bringing the humerus closer to the scapula and potentially increasing impingement on the scapular neck. We hypothesized that correcting retroversion in B2 glenoids would result in increased medialization and worse impingement on the scapular neck. Ten patients with Walch B2 glenoids underwent a simulated RSA. For each patient, a 25 mm baseplate was digitally implanted along the inferior margin of the glenoid, centered anterior-to-posterior, in 0˚ of inclination, with 100% backside contact, with a 36 mm glenosphere and 145˚ neck-shaft angle. Impingement-free ROM was then simulated with 17 different implant arrangements: baseplate version of P (the pathologic version), −15˚, -10˚, −5˚, 0˚, and baseplate lateralization +0, +3mm, +6mm. Two additional simulations consisted of half-wedge baseplates seated at the best fit (matching the paleoglenoid) and 0˚ version. The primary endpoint was external rotation at the side (ERS), based on in-vivo analyses that reveal this as the primary mode of notching and impingement-related instability. Data was analyzed using paired t-test, analysis of variance (ANOVA), and a multivariable regression analysis. In every simulation in every patient, correcting retroversion worsened scapular neck impingement with ERS, the primary mode of notching and impingement-related instability. Overall, implantation in retroversion led to 33% more ERS (P =.02). The magnitude of this effect was much greater with medialized glenoids: 100% more ERS for +0 baseplates and 23% more ERS for +6 (P =.008). Half-wedge baseplates resulted in more ERS than +0 baseplates: 2.3x more at 0˚ version (P =.02). Any correction of version resulted in increased medialization (all P <.01), which led to worse scapular neck impingement. Multiple linear regression analysis showed that baseplate lateralization has the most impact on scapular neck impingement (β = 0.640; P <.001). In B2 glenoids undergoing RSA, correcting the glenoid retroversion with eccentric reaming results in significantly more medialization, worsening scapular neck impingement with ERS. This can increase the risk of notching, may lead to impingement-related instability, and decreases passive ERS. Clinical science study [ABSTRACT FROM AUTHOR]

Background: 3D computer-simulated technology is becoming popular in China. Rhinoplasty with costal cartilage is a good option for Asians. However, the application of 3D imaging in Asian rhinoplasty with costal cartilage has not been systematically assessed. Objective: To analyze the effect of 3D imaging in Asian rhinoplasty with costal cartilage. Methods: In this study, 44 patients were included and randomly divided into 3D and non-3D imaging groups. We performed a prospective survey on the aesthetic scores for preoperative, simulated, and postoperative images and calculated the relative nasal index scores of patients in both groups. Additionally, surveys on satisfactions with surgical outcomes and doctor–patient communication in both groups were conducted. Results: The actual postoperative result was well consistent with the preoperative simulation result. The 3D computer simulation did not impact the satisfaction with surgical outcomes but increased that with doctor–patient communication. The 3D computer-simulated technology was an effective tool for doctor–patient communication and surgery planning in Asian rhinoplasty with costal cartilage. Level of Evidence II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

The photoacoustic (PA) technique is uniquely positioned for biomedical applications primarily due to its ability to visualize optical absorption contrast in deep tissue at ultrasound resolution. In this work, via both three-dimensional (3D) numerical simulations and in vivo experiments on human subjects, we investigated the possibility of PA measurement of human calcaneus bones in vivo in a non-invasive manner, as well as its feasibility to differentiate osteoporosis patients from normal subjects. The results from the simulations and the experiments both demonstrated that, when one side of the heel is illuminated by laser with light fluence under the ANSI safety limit, the PA signal generated in the human calcaneus bone can be detected by an ultrasonic transducer at the other side of the heel (i.e. transmission mode). Quantitative power spectral analyses of the calcaneus bone PA signals were also conducted, demonstrating that the microarchitectural changes in calcaneus bone due to osteoporosis can be detected, as reflected by enhanced high frequency components in detected PA bone signal. Further statistical analysis of the experimental results from 10 osteoporosis patients and 10 healthy volunteers showed that the weighted frequency as a quantified PA spectral parameter can differentiate the two subject groups with statistical significance.

Background: Bochdalek hernia is a common congenital diaphragmatic defect that usually manifests with cardiopulmonary insufficiency in neonates. It is very rare in adults, and symptomatic cases are mostly left-sided. Diaphragmatic defects generally warrant immediate surgical intervention to reduce the risk of incarceration or strangulation of the displaced viscera. Case presentation: A 47-year-old woman presented with dyspnea on exertion. Computed tomography revealed that a large part of the intestinal loop with superior mesenteric vessels and the right kidney were displaced into the right thoracic cavity. Preoperative three-dimensional (3D) simulation software visualized detailed anatomy of displaced viscera and the precise location and size of the diaphragmatic defect. She underwent elective surgery after concomitant pulmonary hypertension was stabilized preoperatively. The laparotomic approach was adopted. Malformation of the liver and the presence of intestinal malrotation were confirmed during the operation. The distal part of the duodenum, jejunum, ileum, colon, and right kidney were reduced into the abdominal cavity consecutively. A large-sized oval defect was closed with monofilament polypropylene mesh. No complications occurred postoperatively. Conclusion: Symptomatic right-sided Bochdalek hernia in adults is exceedingly rare and is frequently accompanied by various visceral anomalies. Accurate diagnosis and appropriate surgical repair are crucial to prevent possible incarceration or strangulation. The preoperative 3D simulation provided comprehensive information on anatomy and concomitant anomalies and helped surgeons plan the operation meticulously and perform procedures safely. [ABSTRACT FROM AUTHOR]

In this work, a full-loop 3D computational fluid dynamics (CFD) numerical simulation of the chemical looping gasification (CLG) process of lignite in a circulating fluidized bed (CFB) was performed using a two-fluid Eulerian-Eulerian model. The results showed that the CFD simulation effectively captured the axial and radial velocities of the particles. More radial flow occurred in the bottom part of the riser and inside the cyclone. The exothermic reaction became dominant within 7s, while the heat-absorbing reaction became dominant between 7 and 15s. The aggregation regions of syngas moved up with that of the high-temperature zone, and CO was the main contributor to the syngas. The particle size in the range of 175–225 μm was inversely proportional to the size of the average heat transfer coefficient (HTC) in the riser. Extremely small particle size saturated the bed, suppressing the HTC. The peak of the HTC was 387.7 W/(m2·K), which occurred in the upper-middle region of the riser and reached. The maximum HTC average value was 180.6 W/(m2·K). Finally, experimental data were used to verify the reliability of the model. [Display omitted] • Simulation of a CLG fuel reactor in a circulating fluidized bed. • Contribute to understanding the rapid fluidization behavior of particles in CFB. • The spatial-temporal distribution of components in riser was investigated. • The spatial-temporal distribution of temperature in riser was investigated. • A study of the heat transfer properties of lignite for the CLG process in a CFB. [ABSTRACT FROM AUTHOR]