A Two-phase Simulation of Wave Impact on a Horizontal Deck Based on SPH Method

AbstractIn this paper, a two-phase numerical model is developed to study the effect of the gas phase in problems of wave attacking deck. The model is based on weakly compressible smoothed particles hydrodynamics (WCSPH) method, and is implemented in C++ and CUDA language to running on GPUs starting from DualSPHysics. Surface tension is considered by incorporating the surface tension force into the momentum equations. Therefore, the continuum surface force (CSF) model is proposed to eliminating the interphase particle penetrations. To calculate surface tension force at interfaces, a color function is assigned to each particle from different phases. Furthermore, to enhance the robustness of this method, the assigned color function is smoothed by calculating the weighted averaging value of initial color function on its support domain. The simulation results are compared with experiment results. The point pressure from numerical results shows well agreement with experimental ones, and is more accurate than one phase simulation. The reason is lying on its satisfying on the condition of air pressure

Effectiveness of Shuxuening injection in coronary heart disease: a systematic review and meta-analysis

Background: Coronary heart disease (CHD) poses a serious threat to public health, and the current medical management still faces significant challenges. Reliable evidence on the efficacy of Shuxuening injection (SXNI) in CHD is still lacking, even though it is widely used in China.Purpose: To evaluate the efficacy of SXNI combination therapy in treating CHD.Methods: A systematic search of eight databases was conducted to identify relevant randomized controlled trials (RCTs) from the inception of each database until June 2023. ROB 2.0, RevMan 5.4, and Stata 15.1 were used for quality evaluation and data analysis. The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the quality of evidence.Results: A total of 3,779 participants from 39 studies were included. The results showed SXNI combination therapy increased the clinical efficacy and decreased the frequency and duration of angina. Furthermore, SXNI combination therapy improved cardiac function of patients by decreasing LVEDD, and increased CI, CO, and LVEF. It also improved blood lipid profiles by increasing HDL, decreasing TC, TG, and LDL. The thrombosis factors of patients were also improved by decreasing FIB, PV, HCT, and HS. Moreover, SXNI combination therapy was superior to the conventional treatment in improving CRP levels, increasing ECG efficacy and BNP. However, due to the limited safety information, reliable safety conclusions could not be drawn. Furthermore, the levels of evidence ranged from very low to moderate due to publication bias and heterogeneity.Conclusion: SXNI can effectively improve angina symptoms, clinical efficacy, cardiac function, blood lipid indicators, and thrombosis factors of patients with CHD. However, more multi-center and large-sample studies are needed to confirm the conclusions due to the limitations of this study.Registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=399606; Identifier: CRD42023433292

Case report of retroperitoneal ectopic pancreas with adrenal adenoma

BackgroundEctopic pancreas is a congenital anomaly in which pancreatic tissue is anatomically separated from the main gland and without vascular or ductal continuity. A case of retroperitoneal ectopic pancreas with adrenal adenoma has never yet been reported.Case PresentationA 54-year-old man presented three masses in the left retroperitoneum, and two of them were resected. The pathologic findings were a retroperitoneal ectopic pancreas with adrenal adenoma.ConclusionWe report an extremely rare case of a retroperitoneal ectopic pancreas and its characterization with dynamic gadolinium-enhanced magnetic resonance imaging (MRI)

Numerical Study of Flat Plate Impact on Water Using a Compressible CIP–IBM–Based Model

Due to the entrapment of compressible air, the process of a flat plate impact on water is complicated, which cannot be reproduced using incompressible simulations. To investigate such a slamming process, an accuracy compressible fluid–structure interaction numerical model has been proposed. The solution of this model is based on the constrained interpolation profile (CIP) method to solve the Navier–Stokes equations for the computation of fluid, and an implicit immersed boundary method (IBM) is used to calculate the fluid–structure interaction. Firstly, the present (CIP–IBM–based) model is validated against the problem of the flow past a stationary cylinder. Then it is implemented to simulate the problem of a rigid flat plate impact on water. The predicated impact pressure is compared with reference experiments and other simulations. The CIP–IBM–based model shows a better performance in dealing with sub-atmospheric pressure and reloading. From the numerical view, it is shown that the oscillation of the slamming pressure is significantly affected by the compression and expansion of the entrapped air cushion, and under the influence of the air cushion, the slamming pressure distribution along the bottom is not constant, which also varies greatly with time

Design and Implementation of a Robust Decision Support System for Marine Space Resource Utilization

Increasing coastal space resource utilization (CSRU) activities and their impact on coastal environments has been recognized as a critical coastal zone stressor. Consequently, the need for sustainable and valid CSRU management has been highlighted. In this study, a highly-intelligent prototype decision-aided system for CSRU was developed. In contrast with existing coastal decision-aided systems, this system is aimed at the management of CSRU, providing reliable and dynamic numerical simulation, analysis, and aided decision making for real coastal engineering based on a self-developed fully automatic numerical program. It was established on multi-tier distributed architecture based on Java EE. The most efficient strategies for spatial data organization, automatic coastal numerical programs, and impact assessment modules are demonstrated. In addition, its integrated construction involving the addition of a new coastal project on the webpage, its one-click numerical prediction of coastal environmental impacts, assessments based on numerical results, and its aided decision-making capabilities are addressed. The system was applied to Ningbo Sea, China, establishing the Ningbo CSRU Decision Support System. Two projects were demonstrated: one reclamation project and one land-based outlet planning case. Results indicated that these projects had detrimental effects on local coastal environments. Therefore, the approvals of these projects were not recommended

An accurate and highly efficient three-dimensional tidal model and its application to Dalian Bay

An accurate and highly efficient semi-implicit three-dimensional tidal model is developed and applied to Dalian Bay. In the model, the pressure gradient in the momentum equations and the velocities in the vertically integrated continuity equation are discretized using the 6 -method, the 6 representing an implicit parameter. At each time step the numerical method requires the solution of one large linear system which can be formally decomposed into a set of small three-diagonal systems coupled with one five-diagonal system. The algorithm has been shown to be fast and accurate. The 3-D model is first tested against an analytical solution for the simple case of rectangular basins. The computed velocity and free surface water elevation results coincide with the analytical results. The model is next applied to Dalian Bay. The predicted results show good agreement with field measurement, verifying the accuracy of the model