scholarly journals Dislocations as a Tool for Nanostructuring Advanced Materials

Physchem ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 225-231
Author(s):  
Vladyslav Turlo
Keyword(s):  
High Resolution ◽  
Transport Properties ◽  
Large Scale ◽  
Functional Materials ◽  
Dislocation Core ◽  
Solute Segregation ◽  
Advanced Materials ◽  
Atomistic Simulations ◽  
Experimental Characterization ◽  
Nanoscale Features

Dislocations present unique opportunities for nanostructuring advanced structural and functional materials due to the recent discoveries of linear complexions thermodynamically stable nanoscale features with unique chemistry and structure confined at dislocations. The formation of such features is driven by solute segregation near the dislocation core and results in the stabilization of dislocations, altering mechanical, thermodynamic, and transport properties of the final material. This perspective article gives an overview of the recent discoveries and predictions made by high-resolution experimental characterization techniques, as well as large-scale atomistic simulations in the newly emerging field of linear complexions.

Fundamentals of Atomistic Simulations

2006 ◽  
Author(s):  
Vasily Bulatov ◽  
Wei Cai
Keyword(s):  
First Principles ◽  
Large Scale ◽  
Dislocation Core ◽  
Boltzmann Distribution ◽  
Atomistic Simulations ◽  
Computationally Efficient ◽  
Interacting Electrons ◽  
Subsequent Discussion ◽  
Necessary And Sufficient ◽  
Interacting Atoms

Fundamentally, materials derive their properties from the interaction between their constituent atoms. These basic interactions make the atoms assemble in a particular crystalline structure. The same interactions also define how the atoms prefer to arrange themselves in the dislocation core. Therefore, to understand the behavior of dislocations, it is necessary and sufficient to study the collective behavior of atoms in crystals populated by dislocations. This chapter introduces the basic methodology of atomistic simulations that will be applied to the studies of dislocations in the following chapters. Section 1 discusses the nature of interatomic interactions and introduces empirical models that describe these interactions with various degrees of accuracy. Section 2 introduces the significance of the Boltzmann distribution that describes statistical properties of a collection of interacting atoms in thermal equilibrium. This section sets the stage for a subsequent discussion of basic computational methods to be used throughout this book. Section 3 covers the methods for energy minimization. Sections 4 and 5 give a concise introduction to Monte Carlo and molecular dynamics methods. When put close together, atoms interact by exerting forces on each other. Depending on the atomic species, some interatomic interactions are relatively easy to describe, while others can be very complicated. This variability stems from the quantum mechanical motion and interaction of electrons [15, 16]. Henceforth, rigorous treatment of interatomic interactions should be based on a solution of Schrödinger’s equation for interacting electrons, which is usually referred to as the first principles or ab initio theory. Numerical calculations based on first principles are computationally very expensive and can only deal with a relatively small number of atoms. In the context of dislocation modelling, relevant behaviors often involve many thousands of atoms and can only be approached using much less sophisticated but more computationally efficient models. Even though we do not use it in this book, it is useful to bear in mind that the first principles theory provides a useful starting point for constructing approximate but efficient models that are needed to study large-scale problems involving many atoms.

scholarly journals Exploiting the quantum mechanically derived force field for functional materials simulations

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Alexey Odinokov ◽  
Alexander Yakubovich ◽  
Won-Joon Son ◽  
Yongsik Jung ◽  
Hyeonho Choi
Keyword(s):  
Force Field ◽  
Large Scale ◽  
Materials Science ◽  
Light Emitting Diode ◽  
Valence Bond ◽  
Functional Materials ◽  
Computational Design ◽  
Chemical Degradation ◽  
Atomistic Simulations ◽  
Molecular Systems

AbstractThe computational design of functional materials relies heavily on large-scale atomistic simulations. Such simulations are often problematic for conventional classical force fields, which require tedious and time-consuming parameterization of interaction parameters. The problem can be solved using a quantum mechanically derived force field (QMDFF)—a system-specific force field derived directly from the first-principles calculations. We present a computational approach for atomistic simulations of complex molecular systems, which include the treatment of chemical reactions with the empirical valence bond approach. The accuracy of the QMDFF is verified by comparison with the experimental properties of liquid solvents. We illustrate the capabilities of our methodology to simulate functional materials in several case studies: chemical degradation of material in organic light-emitting diode (OLED), polymer chain packing, material morphology of organometallic photoresists. The presented methodology is fast, accurate, and highly automated, which allows its application in diverse areas of materials science.

scholarly journals Advanced Materials and Assembly Strategies for Wearable Biosensors: A Review

2020 ◽  
Author(s):  
Eun Kwang Lee ◽  
Hocheon Yoo ◽  
Chi Hwan Lee
Keyword(s):  
Health Monitoring ◽  
Large Scale ◽  
Functional Materials ◽  
Well Being ◽  
Advanced Materials ◽  
Future Research ◽  
Technological Advances ◽  
Inorganic Nanomaterials ◽  
Future Research Directions ◽  
Low Dimensional

Recent technological advances of soft functional materials and their assembly into wearable (i.e., on-skin) biosensors lead to the development of ground-breaking biomedical applications ranging from wearable health monitoring to drug delivery and to human-robot interactions. These wearable biosensors are capable of unobtrusively interfacing with the human skin and enabling long-term reliable monitoring of clinically useful biosignals associated with health and other conditions affecting well-being. Scalable assembly of diverse wearable biosensors has been realized through the elaborate combination of intrinsically stretchable materials including organic polymers or/and low-dimensional inorganic nanomaterials. In this Chapter, we review various types of wearable biosensors within the context of human health monitoring with a focus of their constituent materials, mechanics designs, and large-scale assembly strategies. In addition, we discuss the current challenges and potential future research directions at the end of this chapter.

MODELING THE SOUTH ATLANTIC OCEAN FROM MEDIUM TO HIGH RESOLUTION

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Mariela Gabioux ◽  
Vladimir Santos da Costa ◽  
Joao Marcos Azevedo Correia de Souza ◽  
Bruna Faria de Oliveira ◽  
Afonso De Moraes Paiva
Keyword(s):  
High Resolution ◽  
Atlantic Ocean ◽  
Large Scale ◽  
South Atlantic ◽  
Surface Relaxation ◽  
The South ◽  
Small Surface ◽  
Basic Model ◽  
Basic Set ◽  
Set Up

Results of the basic model configuration of the REMO project, a Brazilian approach towards operational oceanography, are discussed. This configuration consists basically of a high-resolution eddy-resolving, 1/12 degree model for the Metarea V, nested in a medium-resolution eddy-permitting, 1/4 degree model of the Atlantic Ocean. These simulations performed with HYCOM model, aim for: a) creating a basic set-up for implementation of assimilation techniques leading to ocean prediction; b) the development of hydrodynamics bases for environmental studies; c) providing boundary conditions for regional domains with increased resolution. The 1/4 degree simulation was able to simulate realistic equatorial and south Atlantic large scale circulation, both the wind-driven and the thermohaline components. The high resolution simulation was able to generate mesoscale and represent well the variability pattern within the Metarea V domain. The BC mean transport values were well represented in the southwestern region (between Vitória-Trinidade sea mount and 29S), in contrast to higher latitudes (higher than 30S) where it was slightly underestimated. Important issues for the simulation of the South Atlantic with high resolution are discussed, like the ideal place for boundaries, improvements in the bathymetric representation and the control of bias SST, by the introducing of a small surface relaxation. In order to make a preliminary assessment of the model behavior when submitted to data assimilation, the Cooper & Haines (1996) method was used to extrapolate SSH anomalies fields to deeper layers every 7 days, with encouraging results.

scholarly journals Author Correction: High-resolution, large-scale laboratory measurements of a sandy beach and dynamic cobble berm revetment

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Chris E. Blenkinsopp ◽  
Paul M. Bayle ◽  
Daniel C. Conley ◽  
Gerd Masselink ◽  
Emily Gulson ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Sandy Beach ◽  
Laboratory Measurements

A Correction to this paper has been published: https://doi.org/10.1038/s41597-021-00874-2.

scholarly journals Unconventional Materials Processing Using Spark Plasma Sintering

Ceramics ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 20-40
Author(s):  
Ambreen Nisar ◽  
Cheng Zhang ◽  
Benjamin Boesl ◽  
Arvind Agarwal
Keyword(s):  
Spark Plasma Sintering ◽  
Real Life ◽  
Functional Materials ◽  
Research Field ◽  
Advanced Materials ◽  
Plasma Sintering ◽  
Challenges And Opportunities ◽  
Future Challenges ◽  
Gas Quenching ◽  
Spark Plasma

Spark plasma sintering (SPS) has gained recognition in the last 20 years for its rapid densification of hard-to-sinter conventional and advanced materials, including metals, ceramics, polymers, and composites. Herein, we describe the unconventional usages of the SPS technique developed in the field. The potential of various new modifications in the SPS technique, from pressureless to the integration of a novel gas quenching system to extrusion, has led to SPS’ evolution into a completely new manufacturing tool. The SPS technique’s modifications have broadened its usability from merely a densification tool to the fabrication of complex-shaped components, advanced functional materials, functionally gradient materials, interconnected materials, and porous filter materials for real-life applications. The broader application achieved by modification of the SPS technique can provide an alternative to conventional powder metallurgy methods as a scalable manufacturing process. The future challenges and opportunities in this emerging research field have also been identified and presented.

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