Experimental and Molecular Dynamics Simulation Based Investigations on Hydrogen Embrittlement Behavior of Chromium Electroplated 4340 Steel

2021 ◽  
pp. 1-32
Author(s):  
Ozge Dogan ◽  
Mehmet Fazil Kapci ◽  
Volkan Esat ◽  
Burak Bal
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Embrittlement ◽  
Hydrogen Diffusion ◽  
Dynamics Simulation ◽  
Tensile Response ◽  
4340 Steel ◽  
Similar Chemical ◽  
Simulation Based ◽  
Chromium Electroplating ◽  
Electroplating Process

Abstract In this study chromium electroplating process, corresponding hydrogen embrittlement and the effects of baking on hydrogen diffusion are investigated. Three types of materials in the form of Raw 4340 steel, Chromium electroplated 4340 steel, and Chromium electroplated & baked 4340 steel are used in order to shed light into the aforementioned processes. Mechanical and microstructural analyses are carried out to observe the effects of hydrogen diffusion. Mechanical analyses show that tensile strength and hardness of the specimens deteriorate after chrome-electroplating process due to the presence of atomic hydrogen. XRD analyses are carried out for material characterization. Microstructural analyses reveal that hydrogen enters into the material with chromium electroplating process, and baking after chromium electroplating process is an effective way to prevent hydrogen embrittlement. Additionally, effects of hydrogen on the tensile response of ?-Fe based microstructure with similar chemical composition of alloying elements are simulated through Molecular Dynamics (MD) method.

Improved Sampling Strategies for Protein Model Refinement based on Molecular Dynamics Simulation

2020 ◽  
Author(s):  
Lim Heo ◽  
Collin Arbour ◽  
Michael Feig
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Structure Prediction ◽  
Protein Structures ◽  
Conformational Space ◽  
Dynamics Simulation ◽  
Model Refinement ◽  
Protein Model ◽  
Lower Accuracy ◽  
Simulation Based

Protein structures provide valuable information for understanding biological processes. Protein structures can be determined by experimental methods such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, or cryogenic electron microscopy. As an alternative, in silico methods can be used to predict protein structures. Those methods utilize protein structure databases for structure prediction via template-based modeling or for training machine-learning models to generate predictions. Structure prediction for proteins distant from proteins with known structures often results in lower accuracy with respect to the true physiological structures. Physics-based protein model refinement methods can be applied to improve model accuracy in the predicted models. Refinement methods rely on conformational sampling around the predicted structures, and if structures closer to the native states are sampled, improvements in the model quality become possible. Molecular dynamics simulations have been especially successful for improving model qualities but although consistent refinement can be achieved, the improvements in model qualities are still moderate. To extend the refinement performance of a simulation-based protocol, we explored new schemes that focus on an optimized use of biasing functions and the application of increased simulation temperatures. In addition, we tested the use of alternative initial models so that the simulations can explore conformational space more broadly. Based on the insight of this analysis we are proposing a new refinement protocol that significantly outperformed previous state-of-the-art molecular dynamics simulation-based protocols in the benchmark tests described here. <br>

scholarly journals Investigation of the effect of Hydroxychloroquine, Remdesivir, Oseltamivir and some home remedies in the light of Molecular Dynamics Simulation

2020 ◽  
Author(s):  
Keka Talukdar
Keyword(s):  
Molecular Dynamics ◽  
Clinical Trial ◽  
Computer Simulation ◽  
Molecular Dynamics Simulation ◽  
Human Cell ◽  
Physical Modeling ◽  
Chemical Species ◽  
Dynamics Simulation ◽  
Spike Protein ◽  
Simulation Based

Modeling and simulation is another way of finding the interaction between different drugs and chemical species with human cell. Preliminary studies before clinical trial involve computer simulation based on the physical modeling so that clinical trial can be made easier. In many aspects of drug developing, simulation is an essential tool. Here molecular dynamics simulation is performed for the interaction of the spike protein of Covid-19 virus and some of the recently used drugs. Also, the effect of caffeine, theanine, nicotine etc on the virus is found by simulation

Molecular Dynamics Simulation Based Cohesive Zone Representation of Intergranular Fracture Processes in Bicrystalline Graphene

2020 ◽  
Author(s):  
MD Imrul Reza Shishir ◽  
Alireza Tabarraei
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundaries ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Dynamics Simulation ◽  
Zone Model ◽  
Zone Method ◽  
Simulation Based ◽  
Dynamics Simulations ◽  
Fracture Processes

Abstract The fracture properties of various grain boundaries in graphene are investigated using the cohesive zone method (CZM). Molecular dynamics simulations are conducted using REBO2+S potential in order to develop a cohesive zone model for graphene grain boundaries using a double cantilever bicrystalline graphene sheet. The cohesive zone model is used to investigate the traction–separation law to understand the separation-work and strength of grain boundaries.

Crystal orientation dependence of crack growth and stress evolution in single crystal nickel: a molecular dynamics simulation-based cohesive zone model

RSC Advances ◽  
2015 ◽  
Vol 5 (81) ◽  
pp. 65942-65948 ◽  
Author(s):  
Yuan Qi ◽  
Wen-Ping Wu ◽  
Yun-Bing Chen ◽  
Ming-Xiang Chen
Keyword(s):  
Molecular Dynamics ◽  
Cohesive Zone ◽  
Crystal Orientation ◽  
Cohesive Zone Model ◽  
Orientation Dependence ◽  
Dynamics Simulation ◽  
Zone Model ◽  
Stress Evolution ◽  
Slip Bands ◽  
Simulation Based

Void forms in the sample with (100) orientation; brittle fracture in the sample with (110) orientation; blunting and slip bands occurs in the sample with (111) orientation.

Sign in / Sign up

Export Citation Format

Share Document