Direct three-dimensional numerical simulation of nucleate boiling using the level contour reconstruction method

2005 ◽  
Vol 31 (10-11) ◽  
pp. 1231-1242 ◽  
Author(s):  
Seungwon Shin ◽  
S.I. Abdel-Khalik ◽  
Damir Juric
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Nucleate Boiling ◽  
Reconstruction Method ◽  
Contour Reconstruction

Numerical Simulation of Multiple Seeds Interaction During Three-Dimensional Dendritic Solidification With Fluid Flow

2009 ◽  
Author(s):  
Ikroh Yoon ◽  
Seungwon Shin
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Numerical Technique ◽  
Three Dimensional ◽  
Solidification Process ◽  
Small Scale ◽  
Reconstruction Method ◽  
External Fluid ◽  
Fluid Convection ◽  
Dimensional Simulation

Most material of engineering interest undergoes solidification process from liquid to solid state which governs the microstructure of materials. Identifying the growth characteristic of the microstructure during the solidification process is essential to determine the physical properties of final product. Numerical simulation can provide valuable information during solidification process since heat and mass transfer associated with micro-structural growth of dendrite is in greatly small scale which is almost impossible to obtain by experiments. In real situations, dendrite tends to grow from multiple seeds as well as with external fluid flow. Growth characteristics of the dendrites will be greatly influenced by both external fluid convection and interaction between dendrites. In this paper, three-dimensional numerical simulation of multiple dendritic growth during solidification process with melt fluid convection is presented. The high-order Level Contour Reconstruction Method (LCRM), a hybrid form of Front-Tracking and Level-Set, is used to track the moving liquid-solid interface explicitly and sharp interface technique has been used to implement correct phase changing boundary conditions on the moving interface. To get the indicator function and the interface curvature more efficiently and accurately for three-dimensional simulation, we have generated the distance function directly from the interface. The method is validated by comparing with other numerical technique and showed good agreements. Three-dimensional results showed clear difference compared to two-dimensional simulation on growth behavior, especially with multiple seeds.

scholarly journals Contour reconstruction of three-dimensional spiral CT damage image

2018 ◽  
Vol 11 (05) ◽  
pp. 1850028
Author(s):  
Ling-Ling Cui ◽  
Hui Zhang
Keyword(s):  
Feature Matching ◽  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Spiral Ct ◽  
Reconstruction Error ◽  
Statistical Shape Model ◽  
Gradient Algorithm ◽  
Reconstruction Method ◽  
Contour Reconstruction ◽  
Contour Feature

In order to improve the diagnosis and analysis ability of 3D spiral CT and to reconstruct the contour of 3D spiral CT damage image, a contour reconstruction method based on sharpening template enhancement for 3D spiral CT damage image is proposed. This method uses the active contour LasSO model to extract the contour feature of the 3D spiral CT damage image and enhances the information by sharpening the template enhancement technique and makes the noise separation of the 3D spiral CT damage image. The spiral CT image was processed with ENT, and the statistical shape model of 3D spiral CT damage image was established. The gradient algorithm is used to decompose the feature to realize the analysis and reconstruction of the contour feature of the 3D spiral CT damage image, so as to improve the adaptive feature matching ability and the ability to locate the abnormal feature points. The simulation results show that in the 3D spiral CT damage image contour reconstruction, the proposed method performs well in the feature matching of the output pixels, shortens the contour reconstruction time by 20/ms, and provides a strong ability to express the image information. The normalized reconstruction error of CES is 30%, which improves the recognition ability of 3D spiral CT damage image, and increases the signal-to-noise ratio of peak output by 40 dB over other methods.

Three-dimensional reconstruction of the 40S ribosomal subunit from rabbit reticulocytes

1987 ◽  
Vol 45 ◽  
pp. 936-937
Author(s):  
Neng-Yu Zhang ◽  
Terence Wagenknecht ◽  
Michael Radermacher ◽  
Tom Obrig ◽  
Joachim Frank
Keyword(s):  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Uranyl Acetate ◽  
Reconstruction Method ◽  
Single Exposure ◽  
Electron Dose ◽  
Ribosomal Subunits ◽  
40S Ribosomal Subunit ◽  
Dimensional Reconstruction ◽  
Rabbit Reticulocytes

We have reconstructed the 40S ribosomal subunit at a resolution of 4 nm using the single-exposure pseudo-conical reconstruction method of Radermacher et al.Small (40S) ribosomal subunits were Isolated from rabbit reticulocytes, applied to grids and negatively stained (0.5% uranyl acetate) in a manner that “sandwiches” the specimen between two layers of carbon. Regions of the grid exhibiting uniform and thick staining were identified and photographed twice (magnification 49,000X). The first micrograph was always taken with the specimen tilted by 50° and the second was of the Identical area untilted (Fig. 1). For each of the micrographs the specimen was subjected to an electron dose of 2000-3000 el/nm2.Three hundred thirty particles appearing in the L view (defined in [4]) were selected from both tilted- and untilted-specimen micrographs. The untilted particles were aligned and their rotational alignment produced the azimuthal angles of the tilted particles in the conical tilt series.

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