scholarly journals COMPARISON BETWEEN FINITE ELEMNT ANALYSIS AND SEISMIC DISPLACEMENT METHOD ON A TRANSMISSION COEFFICIENT OF SEISMIC AXIAL STRAIN OF SHIELD-DRIVEN TUNNELS

2009 ◽  
Vol 65 (1) ◽  
pp. 236-243 ◽  
Author(s):  
Takeyasu SUZUKI
Keyword(s):  
Transmission Coefficient ◽  
Axial Strain ◽  
Displacement Method ◽  
Seismic Displacement

Study on Production Mechanism of End Concavity in Cross Wedge Rolling

2011 ◽  
Vol 314-316 ◽  
pp. 468-472 ◽  
Author(s):  
Xin Hong Wei ◽  
Xue Dao Shu
Keyword(s):  
Finite Element ◽  
Axial Strain ◽  
Grid Method ◽  
Nonlinear Finite Element ◽  
Production Mechanism ◽  
Displacement Method ◽  
Cross Wedge Rolling ◽  
Material Loss ◽  
Metal Deformation ◽  
Surface Metal

End concavity controlled effectively is one of important factors to achieve no material loss end of workpiece in cross wedge rolling (CWR). In the paper, nonlinear finite element modeling(FEM) for the process of CWR is presented with the aid of DEFORM software. The production mechanism of concavity on the end of rolled-piece is analyzed by displacement method, grid method and axial strain method. The reason of concavity is obtained that the surface metal flows faster than the center and the metal deformation in axle is uneven. The study is significant to avoid end concavity and realize no material loss end for rolled-piece.

scholarly journals Representative Transmission Coefficient for Evaluating the Wave Attenuation Performance of 3D Floating Breakwaters in Regular and Irregular Waves

2021 ◽  
Vol 9 (4) ◽  
pp. 388
Author(s):  
Huu Phu Nguyen ◽  
Jeong Cheol Park ◽  
Mengmeng Han ◽  
Chien Ming Wang ◽  
Nagi Abdussamie ◽  
...  
Keyword(s):  
Transmission Coefficient ◽  
Wave Height ◽  
Wave Attenuation ◽  
Transmitted Wave ◽  
Irregular Waves ◽  
Hydrodynamic Analysis ◽  
Evaluation Approach ◽  
Floating Breakwater ◽  
Floating Breakwaters ◽  
Evaluation Approaches

Wave attenuation performance is the prime consideration when designing any floating breakwater. For a 2D hydrodynamic analysis of a floating breakwater, the wave attenuation performance is evaluated by the transmission coefficient, which is defined as the ratio between the transmitted wave height and the incident wave height. For a 3D breakwater, some researchers still adopted this evaluation approach with the transmitted wave height taken at a surface point, while others used the mean transmission coefficient within a surface area. This paper aims to first examine the rationality of these two evaluation approaches via verified numerical simulations of 3D heave-only floating breakwaters in regular and irregular waves. A new index—a representative transmission coefficient—is then presented for one to easily compare the wave attenuation performances of different 3D floating breakwater designs.

scholarly journals Estimation methods to extract complex permittivity from transmission coefficient in the terahertz band

2021 ◽  
Vol 53 (8) ◽  
Author(s):  
Chuang Yang ◽  
Jian Wang ◽  
Cheng Yang
Keyword(s):  
Transmission Coefficient ◽  
Iterative Algorithm ◽  
Complex Permittivity ◽  
Free Space ◽  
Estimation Methods ◽  
Extraction Technique ◽  
Initial Value ◽  
Terahertz Band ◽  
Terahertz Frequencies

AbstractIn this paper, the characteristics of the transmission coefficient (S$$_{21}$$ 21 ) measured in free-space at terahertz frequencies are analyzed. The analysis results are used to estimate the permittivity of the material under test, and the estimated permittivity is adopted as an initial-value for the iterative algorithm to extract the complex permittivity of the material from the S$$_{21}$$ 21 . The iterative extraction technique based on the estimation is efficient, while the iterative extraction technique without the estimation is inefficient. Various known materials in the literature are used to validate the technique in the terahertz band.

scholarly journals Implementation of the emulsification-diffusion method by solvent displacement for polystyrene nanoparticles prepared from recycled material

RSC Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 2226-2234
Author(s):  
Ana María Pineda-Reyes ◽  
Mauricio Hernández Delgado ◽  
María de la Luz Zambrano-Zaragoza ◽  
Gerardo Leyva-Gómez ◽  
Nestor Mendoza-Muñoz ◽  
...  
Keyword(s):  
Expanded Polystyrene ◽  
Added Value ◽  
Diffusion Method ◽  
Displacement Method ◽  
Polystyrene Nanoparticles ◽  
Solvent Displacement ◽  
Recycled Material

A novel solvent emulsification-displacement method for obtaining polystyrene nanoparticles is reported. This process has an added value and can be an alternative for the recycling of expanded polystyrene.

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