Control of Symmetry Breaking Size and Aspect Ratio in Gold Nanorods: Underlying Role of Silver Nitrate

2017 ◽  
Vol 121 (6) ◽  
pp. 3549-3559 ◽  
Author(s):  
Wenming Tong ◽  
Michael J. Walsh ◽  
Paul Mulvaney ◽  
Joanne Etheridge ◽  
Alison M. Funston
2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Marco Bobinger ◽  
Vasileios Dergianlis ◽  
Markus Becherer ◽  
Paolo Lugli

We review and extend the numerous polyol-based synthesis protocols and postdeposition treatments that have been reported for silver nanowires (AgNWs). After tailoring substantial process parameters such as the process time, temperature as well as the stirring speed, the polyvinylpyrrolidone (PVP) to silver nitrate (AgNO3) ratio, and the type of PVP, a high mean aspect ratio of 800 could be achieved. Interestingly, the addition of a small portion of potassium chloride (KCl) not only leads to a reduction in diameter but also extremely enhances the nanowire dispersion and its stability. This effect is attributed to the role of KCl, which, along with PVP, acts as a cocapping agent. Furthermore, sprayed AgNW and copper nanowire (CuNW) films were tested as transparent heaters. The AgNWs could be operated at a power density of at least 0.72 W/cm2, which corresponds to a temperature of 213°C, whereas the CuNWs failed at a power density and temperature of 0.4 W/cm2 and 150°C, respectively. Interestingly, the degradation of AgNWs shows a step-wise behavior and is mainly dominated by fragmentation, while the CuNWs are gradually oxidized.


2020 ◽  
Vol 48 (3) ◽  
pp. 1243-1253 ◽  
Author(s):  
Sukriti Kapoor ◽  
Sachin Kotak

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.


2021 ◽  
Vol 1152 ◽  
pp. 338277
Author(s):  
Xiaojuan Zhou ◽  
Qiang Liu ◽  
Xiaoyu Shi ◽  
Chunli Xu ◽  
Baoxin Li

2021 ◽  
Vol 128 ◽  
pp. 108558
Author(s):  
Yuyue Guo ◽  
Yangfei Hu ◽  
Xiaojiong Luo ◽  
Shudong Lin ◽  
Jiwen Hu ◽  
...  

1997 ◽  
Vol 56 (20) ◽  
pp. 12947-12960 ◽  
Author(s):  
A. Zawadowski ◽  
G. Zaránd ◽  
P. Nozières ◽  
K. Vladár ◽  
G. T. Zimányi

Author(s):  
Steven W. Burd ◽  
Terrence W. Simon

The vast number of turbine cascade studies in the literature has been performed in straight-endwall, high-aspect-ratio, linear cascades. As a result, there has been little appreciation for the role of, and added complexity imposed by, reduced aspect ratios. There also has been little documentation of endwall profiling at these reduced spans. To examine the role of these factors on cascade hydrodynamics, a large-scale nozzle guide vane simulator was constructed at the Heat Transfer Laboratory of the University of Minnesota. This cascade is comprised of three airfoils between one contoured and one flat endwall. The geometries of the airfoils and endwalls, as well as the experimental conditions in the simulator, are representative of those in commercial operation. Measurements with hot-wire anemometry were taken to characterize the flow approaching the cascade. These measurements show that the flow field in this cascade is highly elliptic and influenced by pressure gradients that are established within the cascade. Exit flow field measurements with triple-sensor anemometry and pressure measurements within the cascade indicate that the acceleration imposed by endwall contouring and airfoil turning is able to suppress the size and strength of key secondary flow features. In addition, the flow field near the contoured endwall differs significantly from that adjacent to the straight endwall.


Sign in / Sign up

Export Citation Format

Share Document