Construction of Credibility Model for Evaluating the Effectiveness of Ecological Civilization Education

The concept of green development as a rational grasp of the relationship between man and nature is not only an important embodiment of the line of thought of seeking truth from facts and advancing with the times but also a concrete application of Marxist materialistic dialectics combined with the current situation of China’s development. Ecological consciousness is a value orientation that reflects the harmonious development of man and nature as a worldview and methodology to explore and reflect on the ecological and environmental problems of the current society. College students are an important force in promoting China’s development in the future, and cultivating their good ecological consciousness with the concept of green development as a guide for action is of great significance at both the theoretical level and the practical level. Based on the review of online reviews, this study proposes that the content of positive reviews can be classified into praiseworthy reviews. In order to verify the objectivity of the content dimensions of the three types of positive comments, this study selected 1,800 positive comments as the research sample using stratified random sampling and conducted a content analysis of the comment samples one by one using the NET method. The content analysis results showed that praiseworthy comments appeared in almost all of the samples, constructive comments appeared in 23% of the samples, and prosocial comments appeared in only 14% of the sample. The results of the content analysis show that it is necessary to identify the dimensions of positive online comments because the single-dimensional constructs cannot effectively present the multidimensional information content contained in positive comments. By studying the geometric modeling method in soft tissue modeling technology, we propose covering the surface model on the outer surface of the physical model and using the tetrahedral mesh as the support skeleton of the physical model. Through the purification of the initial items and secondary testing, a scale with good reliability and validity for measuring the three constructs of praiseworthy, constructive, and prosocial comments was finally obtained.

A Computational Modeling Study to Investigate the Use of Epicranial Electrodes to Deliver Interferential Stimulation to Subcortical Regions

Background: Epicranial cortical stimulation (ECS) is a minimally invasive neuromodulation technique that works by passing electric current between subcutaneous electrodes positioned on the skull. ECS causes a stronger and more focused electric field in the cortex compared to transcranial electric stimulation (TES) where the electrodes are placed on the scalp. However, it is unknown if ECS can target deeper regions where the electric fields become relatively weak and broad. Recently, interferential stimulation (IF) using scalp electrodes has been proposed as a novel technique to target subcortical regions. During IF, two high, but slightly different, frequencies are applied which sum to generate a low frequency field (i.e., 10 Hz) at a target subcortical region. We hypothesized that IF using ECS electrodes would cause stronger and more focused subcortical stimulation than that using TES electrodes.Objective: Use computational modeling to determine if interferential stimulation-epicranial cortical stimulation (IF-ECS) can target subcortical regions. Then, compare the focality and field strength of IF-ECS to that of interferential Stimulation-transcranial electric stimulation (IF-TES) in the same subcortical region.Methods: A human head computational model was developed with 19 TES and 19 ECS disk electrodes positioned on a 10–20 system. After tetrahedral mesh generation the model was imported to COMSOL where the electric field distribution was calculated for each electrode separately. Then in MATLAB, subcortical targets were defined and the optimal configurations were calculated for both the TES and ECS electrodes.Results: Interferential stimulation using ECS electrodes can deliver stronger and more focused electric fields to subcortical regions than IF using TES electrodes.Conclusion: Interferential stimulation combined with ECS is a promising approach for delivering subcortical stimulation without the need for a craniotomy.

CFD MODELLING OF VOLTACAR ELECTRIC VEHICLE BODY FOR THE MOST EFFICIENT DRIVING CONDITIONS

In recent years, fossil fuels prices, greenhouse gas emissions, and need for sustainable energy sources have been increasing day by day. Thus, electric vehicles are seen as a promising candidate in the market due to their low-costs and cleaner fuel options such as electricity, hydrogen etc. Moreover, aerodynamics is one of the most important criteria to consider while designing an automobile for the most efficient driving conditions. For this reason, vehicle developers are studying to reduce drag resistance of the body to improve driving efficiency. On the other hand, Computational Fluid Dynamics (CFD) is one of the main tools for the automotive industry to obtain low-cost results before prototyping of any product. In this study, the aerodynamic characteristics of VoltaCAR electric vehicle is numerically investigated to obtain the best driving velocity. This car participates the TUBITAK-Electromobile car competition every year to achieve low fuel consumption for one hour driving. Thus, it is aimed that to minimize the resistance of the air hitting from the front, side, and roof of the vehicle. In the numerical model, polyhedral mesh structure is preferred to obtain faster convergence with fewer iterations, and shorter computation time is obtained compared to the tetrahedral mesh method. The aerodynamic drag coefficient (Cd) of the car model was calculated as approximately 0.17 at 22.22 and 27.78 m/s. The optimum velocity values were selected as 22.22 and 27.78 m/s by means of their lower Cd.

An efficient method to improve the quality of tetrahedron mesh with MFRC

In this paper, we proposed a novel operation to reconstruction tetrahedrons within a certain region, which we call MFRC (Multi-face reconstruction). During the existing tetrahedral mesh improvement methods, the flip operation is one of the very important components. However, due to the limited area affected by the flip, the improvement of the mesh quality by the flip operation is also very limited. The proposed MFRC algorithm solves this problem. MFRC can reconstruct the local mesh in a larger range and can find the optimal tetrahedron division in the target area within acceptable time complexity. Therefore, based on the MFRC algorithm, we combined other operations including smoothing, edge removal, face removal, and vertex insertion/deletion to develop an effective mesh quality improvement method. Numerical experiments of dozens of meshes show that the algorithm can effectively improve the low-quality elements in the tetrahedral mesh, and can effectively reduce the running time, which has important significance for the quality improvement of large-scale mesh.

Numerical Assessment of the Hybrid Approach for Simulating Three-Dimensional Flow and Advective Transport in Fractured Rocks

This study presents a hybrid approach for simulating flow and advective transport dynamics in fractured rocks. The developed hybrid domain (HD) model uses the two-dimensional (2D) triangular mesh for fractures and tetrahedral mesh for the three-dimensional (3D) rock matrix in a simulation domain and allows the system of equations to be solved simultaneously. This study also illustrates the HD model with two numerical cases that focus on the flow and advective transport between the fractures and rock matrix. The quantitative assessments are conducted by comparing the HD results with those obtained from the discrete fracture network (DFN) and equivalent continuum porous medium (ECPM) models. Results show that the HD model reproduces the head solutions obtained from the ECPM model in the simulation domain and heads from the DFN model in the fractures in the first case. The particle tracking results show that the mean particle velocity in the HD model can be 7.62 times higher than that obtained from the ECPM mode. In addition, the developed HD model enables detailed calculations of the fluxes at intersections between fractures and cylinder objects in the case and obtains relatively accurate flux along the intersections. The solutions are the key factors to evaluate the sources of contaminant released from the disposal facility.

Nonlinear finite element analysis of lumbar spine under mechanical load

Nonlinear Finite Element Analysis of lumbar spine is carried out using the optimisation software, to determine the effect of accidents on the human spine under mechanical loading. The lower two lumbar section – L4 and L5 of spinal cord is focussed in the present study. A simplified model of the L4-L5 vertebra was prepared. Bone material was taken as nonlinear and disc centre was modelled as hyper elastic. The ligaments are modelled as 1D truss elements. 2 D triangular mesh was generated and converted to 3D tetrahedral mesh. The range of force of 500 N to 1600N and moment of 7500 Nm was given as an input. The relationship of displacement, stress and strain with force is studied. The analysis was carried out and the results obtained depicted that the force varies depending on the impact of accidents. Conclusions are drawn and the relationship at different values of force was obtained.

Numerical Modelling of TEM Fields by the Edge-Based Finite Element Method Using Tetrahedral Element for Central Rectangular Loops

In this study, we have implemented an edge-based finite element method for the numerical modeling of the transient electromagnetic method. We took the Helmholtz equation of the electric field as the governing equation for the edge-based finite element analysis. The modeling domain was discretized using linear tetrahedral mesh supported by Whitney-type vector basis functions. We inferred the equations by applying the Galerkin method. The system of equation was solved using a corrected version of the Bi Conjugate Gradient Stabilized Method (BiCGStab) algorithm to reduce the computational time. We obtained numerical solution for electric field in the Laplace domain; then the field was transformed into the time domain using the Gaver-Stehfest algorithm. Following this, the impulse response of the magnetic field was obtained through the Faraday law of electromagnetic induction as it is considerably more stable and computationally more efficient than inversion using the Fourier Transform. 3D geoelectric models were used to investigate the convergence of the edge-based finite element method with the analytic solution. The results are in good agreement with the analytical solution value for two resistivity contrasts in the 3D geoelectric brick model. We also compared the results of tetrahedral elements with the brick element in the 3D horizontal sheet and 3D conductive brick model. The results indicated that these two elements show very similar errors, but tetrahedral reflects fewer relative errors. For the low resistivity geoelectric model, numerical checks against the analytical solution, integral-equation method, and finite-difference time-domain solutions showed that the solutions would provide accurate results.

Application of Polyhedral Mesh for Vortex Formation Study for Simple Single Pump Sump

Meshing of domain in CFD is an important step to ensure accuracy of the solution. In the past, hexahedral or tetrahedral mesh systems were commonly used, and both have their merits and demerits. For large and complex geometry, polyhedral is another option but its accuracy is claimed to be lacking. In this paper, the use of polyhedral mesh system by past researchers are reviewed. Evaluation on the application of polyhedral mesh system for the study of the vortex formation with a simple single pump sump model is made. Validation was made through the comparison of the results from hexahedral, tetrahedral and polyhedral mesh sizes and the experimental data from published data. The polyhedral mesh system was found to perform satisfactorily and was able to match the results from the hexahedral mesh system as well as the experimental data.