scholarly journals Molecular Simulation of Crystallisation in External Electric Fields: A Review

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 316
Author(s):  
Niall J. English

Elucidating the underlying mechanisms of molecular solidification in both homo- and hetero-geneous systems is of paramount importance for a large swathe of natural phenomena (whether on Earth or throughout the Universe), as well as a whole litany of industrial processes. One lesser-studied aspect of these disorder-order transitions is the effect of external applied fields, shifting both thermodynamic driving forces and underlying kinetics, and, indeed, fundamental mechanisms themselves. Perhaps this is nowhere more apparent than in the case of externally-applied electric fields, where there has been a gradually increasing number of reports in recent years of electro-manipulated crystallisation imparted by such electric fields. Drawing motivations from both natural phenomena, state-of-the-art experiments and, indeed, industrial applications, this review focusses on how non-equilibrium molecular simulation has helped to elucidate crystallisation phenomena from a microscopic perspective, as well as offering an important, predictive molecular-design approach with which to further refine in-field-crystallisation operations.

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1405
Author(s):  
Niall J. English

Unpacking the mechanistic insights into how externally applied electric fields affect the physicochemical properties of crystals represents a challenge of great importance for a plethora of natural phenomena, in addition to a broad array of industrial operations and technologies. As such, the key goals in such field effect studies centre around how thermodynamic and kinetic relaxation processes in crystals are affected, including charge carrier conduction and energy transfer processes, and this is a very recent area of fundamental scrutiny. Indeed, in recent years, there has been a steadily mounting number of reports of field-manipulated crystal-state phenomena. Taking as the background a range of natural phenomena, phenomenological theory, state-of-the-art experiments and technological observations, the present review examines the role of nonequilibrium molecular simulation in its scrutiny of intra-crystal phenomena from an atomistic viewpoint, in addition to providing a framework for a predictive molecular design philosophy by which to refine field crystal understanding.


Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.


2021 ◽  
Author(s):  
Tingting Chen ◽  
Yu Sheng ◽  
Zhaodong Hao ◽  
Xiaofei Long ◽  
Fangfang Fu ◽  
...  

Abstract Polyploidy generally provides an advantage in phenotypic variation and growth vigor. However, the underlying mechanisms remain poorly understood. The tetraploid L. sino-americanum exhibits altered morphology compared to its diploid counterpart, including larger, thicker and deeper green leaves, bigger stomata, thicker stems and increased tree height. Such characteristics can be useful in ornamental and industrial applications. To elucidate the molecular mechanisms behind this variation, we performed a comparative transcriptome and proteome analysis. Our transcriptome data indicated that some photosynthesis genes and pathways were differentially altered and enriched in tetraploid L. sino-americanum, mainly related to F-type ATPase, the cytochrome b6/f complex, photosynthetic electron transport, the light harvesting chlorophyll protein complexes, photosystem I and II. Most of the differentially expressed proteins we could identify are also involved in photosynthesis. Our physiological results showed that tetraploids have an enhanced photosynthetic capacity, concomitant with great levels of sugar and starch in leaves. This suggests that tetraploid L. sino-americanum might experience comprehensive transcriptome reprogramming of genes related to photosynthesis. This study has especially emphasized molecular changes involved in photosynthesis that accompany polyploidy, and provides a possible explanation for the altered phenotype of polyploidy plants in comparison to their diploid form.


2021 ◽  
Vol 141 ◽  
pp. 110757 ◽  
Author(s):  
Falk Cudok ◽  
Niccolò Giannetti ◽  
José L. Corrales Ciganda ◽  
Jun Aoyama ◽  
P. Babu ◽  
...  

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1459 ◽  
Author(s):  
Tamás Czimmermann ◽  
Gastone Ciuti ◽  
Mario Milazzo ◽  
Marcello Chiurazzi ◽  
Stefano Roccella ◽  
...  

This paper reviews automated visual-based defect detection approaches applicable to various materials, such as metals, ceramics and textiles. In the first part of the paper, we present a general taxonomy of the different defects that fall in two classes: visible (e.g., scratches, shape error, etc.) and palpable (e.g., crack, bump, etc.) defects. Then, we describe artificial visual processing techniques that are aimed at understanding of the captured scenery in a mathematical/logical way. We continue with a survey of textural defect detection based on statistical, structural and other approaches. Finally, we report the state of the art for approaching the detection and classification of defects through supervised and non-supervised classifiers and deep learning.


Actuators ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 60 ◽  
Author(s):  
Rouven Britz ◽  
Paul Motzki ◽  
Stefan Seelecke

In industrial applications, rotatory motions and torques are often needed. State-of-the-art actuators are based on either combustion engines, electro-motors, hydraulic, or pneumatic machines. The main disadvantages are the construction space, the high weight, and a large amount of needed peripheral devices. To overcome these limitations, compact and light-weight actuator systems can be built by using shape memory alloys (SMAs), which are known for their superior energy density. In this paper, the development of a scalable bi-directional rotational actuator based on SMA wires is presented. The scalability was based on a modular design, which allowed the actuator to be adapted to various application specifications by customizing the rotational angle and the output torque. On the mechanical side, each module enabled a small rotatory motion, which added up to the total angle of the actuator. The SMA wires were arranged in an agonist-antagonist configuration to provide active rotation in both directions. The presented prototype achieved a total rotation of 100°. The modularity of the mechanical concept is also reflected in the electronics, which is discussed in this paper as well. This consideration allows the electronics to be adapted to the mechanics with minimal changes. As a result, a prototype, including the presented mechanical and electronic design, is reported in this study.


2020 ◽  
Vol 11 (3) ◽  
pp. 47
Author(s):  
Floris Honig ◽  
Steven Vermeulen ◽  
Amir A. Zadpoor ◽  
Jan de Boer ◽  
Lidy E. Fratila-Apachitei

The ability to control the interactions between functional biomaterials and biological systems is of great importance for tissue engineering and regenerative medicine. However, the underlying mechanisms defining the interplay between biomaterial properties and the human body are complex. Therefore, a key challenge is to design biomaterials that mimic the in vivo microenvironment. Over millions of years, nature has produced a wide variety of biological materials optimised for distinct functions, ranging from the extracellular matrix (ECM) for structural and biochemical support of cells to the holy lotus with special wettability for self-cleaning effects. Many of these systems found in biology possess unique surface properties recognised to regulate cell behaviour. Integration of such natural surface properties in biomaterials can bring about novel cell responses in vitro and provide greater insights into the processes occurring at the cell-biomaterial interface. Using natural surfaces as templates for bioinspired design can stimulate progress in the field of regenerative medicine, tissue engineering and biomaterials science. This literature review aims to combine the state-of-the-art knowledge in natural and nature-inspired surfaces, with an emphasis on material properties known to affect cell behaviour.


2020 ◽  
Vol 6 (21) ◽  
pp. eaaz2915 ◽  
Author(s):  
Zdenek Futera ◽  
John S. Tse ◽  
Niall J. English

In a superionic (SI) ice phase, oxygen atoms remain crystallographically ordered while protons become fully diffusive as a result of intramolecular dissociation. Ice VII’s importance as a potential candidate for a SI ice phase has been conjectured from anomalous proton diffusivity data. Theoretical studies indicate possible SI prevalence in large-planet mantles (e.g., Uranus and Neptune) and exoplanets. Here, we realize sustainable SI behavior in ice VII by means of externally applied electric fields, using state-of-the-art nonequilibrium ab initio molecular dynamics to witness at first hand the protons’ fluid dance through a dipole-ordered ice VII lattice. We point out the possibility of SI ice VII on Venus, in its strong permanent electric field.


2020 ◽  
Vol 12 (5) ◽  
pp. 1187-1215 ◽  
Author(s):  
Pallavi Kumari ◽  
Visakh V.S. Pillai ◽  
Antonio Benedetto

Abstract Ionic liquids (ILs) are a relatively new class of organic electrolytes composed of an organic cation and either an organic or inorganic anion, whose melting temperature falls around room-temperature. In the last 20 years, the toxicity of ILs towards cells and micro-organisms has been heavily investigated with the main aim to assess the risks associated with their potential use in (industrial) applications, and to develop strategies to design greener ILs. Toxicity, however, is synonym with affinity, and this has stimulated, in turn, a series of biophysical and chemical-physical investigations as well as few biochemical studies focused on the mechanisms of action (MoAs) of ILs, key step in the development of applications in bio-nanomedicine and bio-nanotechnology. This review has the intent to present an overview of the state of the art of the MoAs of ILs, which have been the focus of a limited number of studies but still sufficient enough to provide a first glimpse on the subject. The overall picture that emerges is quite intriguing and shows that ILs interact with cells in a variety of different mechanisms, including alteration of lipid distribution and cell membrane viscoelasticity, disruption of cell and nuclear membranes, mitochondrial permeabilization and dysfunction, generation of reactive oxygen species, chloroplast damage (in plants), alteration of transmembrane and cytoplasmatic proteins/enzyme functions, alteration of signaling pathways, and DNA fragmentation. Together with our earlier review work on the biophysics and chemical-physics of IL-cell membrane interactions (Biophys. Rev. 9:309, 2017), we hope that the present review, focused instead on the biochemical aspects, will stimulate a series of new investigations and discoveries in the still new and interdisciplinary field of “ILs, biomolecules, and cells.”


Sign in / Sign up

Export Citation Format

Share Document