Vapor−Liquid and Vapor−Solid Phase Equilibria of Fullerenes:  The Role of the Potential Shape on the Triple Point

2003 ◽  
Vol 107 (44) ◽  
pp. 12320-12323 ◽  
Author(s):  
Bin Chen ◽  
J. Ilja Siepmann ◽  
Sami Karaborni ◽  
Michael L. Klein
2018 ◽  
Vol 17 (4) ◽  
pp. 272-279 ◽  
Author(s):  
Yudan Zhu ◽  
Shuzhang Zhang ◽  
Yijun Feng ◽  
Qian Xiao ◽  
Jiwei Cheng ◽  
...  

Background & Objective: The large conductance calcium-activated potassium (BK) channel, extensively distributed in the central nervous system (CNS), is considered as a vital player in the pathogenesis of epilepsy, with evidence implicating derangement of K+ as well as regulating action potential shape and duration. However, unlike other channels implicated in epilepsy whose function in neurons could clearly be labeled “excitatory” or “inhibitory”, the unique physiological behavior of the BK channel allows it to both augment and decrease the excitability of neurons. Thus, the role of BK in epilepsy is controversial so far, and a growing area of intense investigation. Conclusion: Here, this review aims to highlight recent discoveries on the dichotomous role of BK channels in epilepsy, focusing on relevant BK-dependent pro- as well as antiepileptic pathways, and discuss the potential of BK specific modulators for the treatment of epilepsy.


Author(s):  
David L. Kirchman

Geomicrobiology, the marriage of geology and microbiology, is about the impact of microbes on Earth materials in terrestrial systems and sediments. Many geomicrobiological processes occur over long timescales. Even the slow growth and low activity of microbes, however, have big effects when added up over millennia. After reviewing the basics of bacteria–surface interactions, the chapter moves on to discussing biomineralization, which is the microbially mediated formation of solid minerals from soluble ions. The role of microbes can vary from merely providing passive surfaces for mineral formation, to active control of the entire precipitation process. The formation of carbonate-containing minerals by coccolithophorids and other marine organisms is especially important because of the role of these minerals in the carbon cycle. Iron minerals can be formed by chemolithoautotrophic bacteria, which gain a small amount of energy from iron oxidation. Similarly, manganese-rich minerals are formed during manganese oxidation, although how this reaction benefits microbes is unclear. These minerals and others give geologists and geomicrobiologists clues about early life on Earth. In addition to forming minerals, microbes help to dissolve them, a process called weathering. Microbes contribute to weathering and mineral dissolution through several mechanisms: production of protons (acidity) or hydroxides that dissolve minerals; production of ligands that chelate metals in minerals thereby breaking up the solid phase; and direct reduction of mineral-bound metals to more soluble forms. The chapter ends with some comments about the role of microbes in degrading oil and other fossil fuels.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 503
Author(s):  
Jaehyun Lee ◽  
Ehsan Esmaili ◽  
Giho Kang ◽  
Baekhoon Seong ◽  
Hosung Kang ◽  
...  

The dimple occurs by sudden pressure inversion at the droplet’s bottom interface when a droplet collides with the same liquid-phase or different solid-phase. The air film entrapped inside the dimple is a critical factor affecting the sequential dynamics after coalescence and causing defects like the pinhole. Meanwhile, in the coalescence dynamics of an electrified droplet, the droplet’s bottom interfaces change to a conical shape, and droplet contact the substrate directly without dimple formation. In this work, the mechanism for the dimple’s suppression (interfacial change to conical shape) was studied investigating the effect of electric pressure. The electric stress acting on a droplet interface shows the nonlinear electric pressure adding to the uniform droplet pressure. This electric stress locally deforms the droplet’s bottom interface to a conical shape and consequentially enables it to overcome the air pressure beneath the droplet. The electric pressure, calculated from numerical tracking for interface and electrostatic simulation, was at least 108 times bigger than the air pressure at the center of the coalescence. This work helps toward understanding the effect of electric stress on droplet coalescence and in the optimization of conditions in solution-based techniques like printing and coating.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1681
Author(s):  
Hadi Hijazi ◽  
Vladimir G. Dubrovskii

The vapor–liquid–solid growth of III-V nanowires proceeds via the mononuclear regime, where only one island nucleates in each nanowire monolayer. The expansion of the monolayer is governed by the surface energetics depending on the monolayer size. Here, we study theoretically the role of surface energy in determining the monolayer morphology at a given coverage. The optimal monolayer configuration is obtained by minimizing the surface energy at different coverages for a set of energetic constants relevant for GaAs nanowires. In contrast to what has been assumed so far in the growth modeling of III-V nanowires, we find that the monolayer expansion may not be a continuous process. Rather, some portions of the already formed monolayer may dissolve on one of its sides, with simultaneous growth proceeding on the other side. These results are important for fundamental understanding of vapor–liquid–solid growth at the atomic level and have potential impacts on the statistics within the nanowire ensembles, crystal phase, and doping properties of III-V nanowires.


2016 ◽  
Vol 61 (8) ◽  
pp. 2700-2711 ◽  
Author(s):  
Petri Uusi-Kyyny ◽  
Simona Ionita ◽  
Muhammad Saad Qureshi ◽  
Ville Alopaeus ◽  
Dominique Richon

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