Long Time Memory of Lagrangian Acceleration Statistics in 2D and 3D Turbulence

This paper presents the validation of active and passive, made by a dissipation beach, numerical absorbing methods implemented in RANS-VOF FLUENT® code for modelling long time series of wave propagation interacting with coastal structures. Verification of both numerical techniques was performed in 2D – wave flume, and 3D – wave tank, this one using a multiple active absorption wave makers. The active absorption wave maker allows maintaining the incident wave generation and the mean water level along the time. Good results were obtained for 2D and 3D applications for active absorption wave maker at the generation boundary and both numerical beach and active absorption at the end of the flume/tank.

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Characterization Of Oxide Layers Formed On 13CrMo4-5 Steel Operated For A Long Time At An Elevated Temperature

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0305 ◽

2015 ◽

Vol 60 (3) ◽

pp. 1783-1788 ◽

Cited By ~ 1

Author(s):

M. Gwoździk

Keyword(s):

Elevated Temperature ◽

Oxide Layer ◽

Steel Substrate ◽

Scratch Test ◽

Scanning Microscope ◽

Oxide Layers ◽

Optical Scanning ◽

Long Time ◽

2D And 3D

Abstract The paper contains results of studies into the formation of oxide layers on 13CrMo4-5 (15HM) steel long-term operated at an elevated temperature. The oxide layer was studied on a surface and a cross-section at the inner and outer surface of the tube wall. The 13CrMo4-5 steel operated at the temperature of 470°C during 190,000 hours was investigated. X-ray structural examinations (XRD) were carried out, microscope observation s using an optical, scanning microscope were performed. The native material chemical composition was analysed by means of emission spark spectroscopy, while that of oxide layers on a scanning microscope (EDS). The studies on the topography of the oxide layers comprised studies on the roughness plane, which were carried out using a AFM microscope designed for 2D and 3D studies on the surface. Mechanical properties of the oxide layer – steel (substrate) were characterised on the basis of scratch test. The adhesion of oxide layers, friction force, friction coefficient, scratching depth were determined as well as the force at which the layer was delaminated.

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A DETAILED REVIEW ON FINGERPRINT DOOR LOCK SYSTEM

International Journal of Engineering Applied Sciences and Technology ◽

10.33564/ijeast.2021.v06i04.041 ◽

2021 ◽

Vol 6 (4) ◽

Author(s):

Vivek R ◽

Gokul Shyam D ◽

Jai Adithya R ◽

Mukilan T Sriram ◽

Nihal V

Keyword(s):

Fingerprint Recognition ◽

Fingerprint Identification ◽

Detailed Review ◽

Detection Process ◽

Common Causes ◽

Behavioral Features ◽

Long Time ◽

Facial Pattern ◽

Door Lock ◽

2D And 3D

Passwords and Tokens are extremely vulnerable and are easily stolen or lost. A poor password is one of the most common causes of security and data breaches. Hacker attacks target even the strongest passwords. Resetting the password takes a long time and can cause the employee to lose productivity. Biometrics can be used to solve the problem. It is the method of recognizing or confirming individuals based on physiological or behavioral features such as the iris, fingerprints, facial pattern, DNA, speech patterns, and so on. The concept of distinguishing individuals based on their fingerprints goes back thousands of years. It first became famous in the 1970’s. The detection and authentication of fingerprints is the method of fingerprint identification. Fingerprint identification is the most commonly used biometric. This research paper explains the main characteristics of fingerprints and how the Automatic Minutiae Detection process works, as well as comparing 2D and 3D fingerprint recognition

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Benchmarking Numerical Methods for Impact and Cratering Applications

Applied Sciences ◽

10.3390/app11062504 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2504

Author(s):

Wendy K. Caldwell ◽

Bryan Euser ◽

Catherine S. Plesko ◽

Carene Larmat ◽

Zhou Lei ◽

...

Keyword(s):

Numerical Methods ◽

Solar System ◽

Discrete Element Method ◽

Large Scale ◽

Computational Models ◽

Published Data ◽

Impact Cratering ◽

Long Time ◽

Large Length ◽

2D And 3D

Large scale computational models are important for studying impact cratering events that are prevalent both on Earth and, more broadly, in this solar system. To address these problems, models must reliably account for both large length scales (e.g., kilometers) and relatively long time scales (hundreds of seconds). This work benchmarks two such approaches, a more traditional hydrodynamics approach and a finite-discrete element method (FDEM), for impact cratering applications. Both 2D and 3D results are discussed for two different impact velocities, 5 km/s and 20 km/s, striking normal to the target and, for 3D simulations, 45° from vertical. In addition, comparisons to previously published data are presented. Finally, differences in how these methods model damage are discussed. Ultimately, both approaches show successful modeling of several different impact scenarios.

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MULTIVARIATE INTERPOLATION USING POLYHARMONIC SPLINES

Acta Polytechnica ◽

10.14311/ap.2021.61.0148 ◽

2021 ◽

Vol 61 (SI) ◽

pp. 148-154

Author(s):

Karel Segeth

Keyword(s):

Arbitrary Dimension ◽

Basis Functions ◽

Computational Mathematics ◽

L2 Norm ◽

Long Time ◽

Polyharmonic Spline ◽

Polyharmonic Splines ◽

2D And 3D ◽

Derivatives Of ◽

Spline Interpolant

Data measuring and further processing is the fundamental activity in all branches of science and technology. Data interpolation has been an important part of computational mathematics for a long time. In the paper, we are concerned with the interpolation by polyharmonic splines in an arbitrary dimension. We show the connection of this interpolation with the interpolation by radial basis functions and the smooth interpolation by generating functions, which provide means for minimizing the L2 norm of chosen derivatives of the interpolant. This can be useful in 2D and 3D, e.g., in the construction of geographic information systems or computer aided geometric design. We prove the properties of the piecewise polyharmonic spline interpolant and present a simple 1D example to illustratethem.

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Optimized Coatings/Substrate Combinations Under Contact Loadings Through a Combined Experimental and Numerical Methodology

World Tribology Congress III, Volume 2 ◽

10.1115/wtc2005-63477 ◽

2005 ◽

Author(s):

M. C. Baietto Dubourg

Keyword(s):

Numerical Models ◽

Single Layer ◽

Complete Characterization ◽

Scratch Hardness ◽

Graded Coatings ◽

Fatigue Data ◽

Long Time ◽

2D And 3D ◽

Empirical Approaches ◽

Wear Tests

For a long time the search of suitable coatings/substrate combinations was mainly based on empirical approaches using results issued from scratch, hardness, wear tests or extrapolating previous experiences to different configurations. There is an increasing need to understand and to be able to predict the performance of the coatings To reach these objectives a methodology encompassing the development of coatings, the complete characterization, the testing and the modeling must be carried out, requiring a multi-disciplinary approach implying collaborations. Concerning the characterization, the number of parameters to be addressed is huge, spanning from micro-structural, materials, physical, mechanical and surface properties to the behavior of complex coatings/substrate systems under representative loading conditions. Further these properties may be thickness dependant. In addition, there is a serious lack in fundamental resistance, fatigue data of the coatings and the interfaces. The choice is all the more difficult since many coating combinations are feasible, from single layer to multilayered coatings or graded coatings over a substrate. A review of the different 2D and 3D numerical models developed will be presented with some applications.

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Analysis of 2D and 3D defects associated with precipitation of Cu in silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008866x ◽

1991 ◽

Vol 49 ◽

pp. 870-871

Author(s):

P.M. Rice ◽

MJ. Kim ◽

R.W. Carpenter

Keyword(s):

Colony Growth ◽

Dark Field ◽

Dark Side ◽

Silicide Phase ◽

Strain Fields ◽

Near Surface ◽

Unknown Composition ◽

Secondary Precipitates ◽

20 Nm ◽

2D And 3D

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.

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200kv superconducting cryo electron microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100127645 ◽

1987 ◽

Vol 45 ◽

pp. 642-643

Author(s):

M. Iwatsuki ◽

Y. Kokubo ◽

Y. Harada ◽

J. Lehman

Keyword(s):

Electron Microscope ◽

Structure Analysis ◽

Organic Materials ◽

Strong Interactions ◽

Specimen Preparation ◽

Great Effort ◽

Electron Microscopic ◽

Crystal Fields ◽

Special Skill ◽

Long Time

In recent years, the electron microscope has been significantly improved in resolution and we can obtain routinely atomic-level high resolution images without any special skill. With this improvement, the structure analysis of organic materials has become one of the interesting targets in the biological and polymer crystal fields.Up to now, X-ray structure analysis has been mainly used for such materials. With this method, however, great effort and a long time are required for specimen preparation because of the need for larger crystals. This method can analyze average crystal structure but is insufficient for interpreting it on the atomic or molecular level. The electron microscopic method for organic materials has not only the advantage of specimen preparation but also the capability of providing various information from extremely small specimen regions, using strong interactions between electrons and the substance. On the other hand, however, this strong interaction has a big disadvantage in high radiation damage.

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A Stationary Solution of High-Energy Electron Reflection (HEER) for An Arbitrary Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135472 ◽

1990 ◽

Vol 48 (2) ◽

pp. 374-375

Author(s):

YIQUN MA

Keyword(s):

Stationary Solution ◽

High Energy ◽

Bloch Wave ◽

Dynamical Theory ◽

High Energy Electron ◽

Bulk Materials ◽

Periodic Surface ◽

Electron Transmission ◽

Electron Reflection ◽

Long Time

For a long time, the development of dynamical theory for HEER has been stagnated for several reasons. Although the Bloch wave method is powerful for the understanding of physical insights of electron diffraction, particularly electron transmission diffraction, it is not readily available for the simulation of various surface imperfection in electron reflection diffraction since it is basically a method for bulk materials and perfect surface. When the multislice method due to Cowley & Moodie is used for electron reflection, the “edge effects” stand firmly in the way of reaching a stationary solution for HEER. The multislice method due to Maksym & Beeby is valid only for an 2-D periodic surface.Now, a method for solving stationary solution of HEER for an arbitrary surface is available, which is called the Edge Patching method in Multislice-Only mode (the EPMO method). The analytical basis for this method can be attributed to two important characters of HEER: 1) 2-D dependence of the wave fields and 2) the Picard iteractionlike character of multislice calculation due to Cowley and Moodie in the Bragg case.

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