Direct Observation of Three-Dimensional Atomic Structure of Twinned Metallic Nanoparticles and Their Catalytic Properties

Nano Letters ◽  
2022 ◽  
Author(s):  
Juhyeok Lee ◽  
Chaehwa Jeong ◽  
Taegu Lee ◽  
Seunghwa Ryu ◽  
Yongsoo Yang
Author(s):  
J.L. Williams ◽  
K. Heathcote ◽  
E.J. Greer

High Voltage Electron Microscope already offers exciting experimental possibilities to Biologists and Materials Scientists because the increased specimen thickness allows direct observation of three dimensional structure and dynamic experiments on effectively bulk specimens. This microscope is designed to give maximum accessibility and space in the specimen region for the special stages which are required. At the same time it provides an ease of operation similar to a conventional instrument.


Nanoscale ◽  
2021 ◽  
Author(s):  
Pei Liu ◽  
Ece Arslan Imran ◽  
Annick De Backer ◽  
Annelies de Wael ◽  
Ivan Lobato ◽  
...  

Au nanoparticles (NPs) deposited on CeO2 are extensively used as thermal catalysts since the morphology of the NPs is expected to be stable at elevated temperatures. Although it is well...


2021 ◽  
pp. 57-57
Author(s):  
Zakaria Lafdaili ◽  
Sakina El-Hamdani ◽  
Abdelaziz Bendou ◽  
Karim Limam ◽  
Bara El-Hafad

In this work we study numerically the three-dimensional turbulent natural convection in a partially heated cubic cavity filled with water containing metallic nanoparticles, metallic oxides and others based on carbon.The objective is to study and compare the effect of the addition of nanoparticles studied in water and also the effect of the position of the heated partition on the heat exchange by turbulent natural convection in this type of geometry, which can significantly improve the design of heat exchange systems for better space optimization. For this we have treated numerically for different volume fractions the turbulent natural convection in the two cases where the cavity is heated respectively by a vertical and horizontal strip in the middle of one of the vertical walls. To take into account the effects of turbulence, we used the standard turbulence model ? - ?. The governing equations are discretized by the finite volume method using the power law scheme which offers a good stability characteristic in this type of flow. The results are presented in the form of isothermal lines and current lines. The variation of the mean Nusselt number is calculated for the two positions of the heated partition as a function of the volume fraction of the nanoparticles studied in water for different Rayleigh numbers.The results show that carbon-based nanoparticles intensify heat exchange by convection better and that the position of the heated partition significantly influences heat exchange by natural convection. In fact, an improvement in the average Nusselt number of more than 20% is observed for the case where the heated partition is horizontal.


2021 ◽  
Vol 25 ◽  
Author(s):  
Luis Daniel Pedro-Hernández ◽  
Marcos Martínez-García

: Dendrimers are highly branched three-dimensional macromolecules with a highly controlled structure, a single molecular weight, numerous controllable dendritic branches and peripheral functionalities, as well as the tendency to adopt an ellipsoid or spheroid shape once a certain size is reached. These features have made them attractive for application in pharmaceutical and medicinal chemistry in gene transfection, as medical imaging agents, and as drug carriers in potential drug delivery agents. The incorporation of metallic species into dendritic molecules has also been reported; the focus has been on organometallic dendrimers with metallic species only at specific positions of the molecules, such as the core, dendritic branches and the periphery, studied for their magnetic, electronic, and photo-optical or catalytic properties. Dendrimers have been investigated for optoelectronic applications (adsorption, emission, laser emission, nonlinear optics) through the encapsulation of active units by dendritic branches, core and peripheral. This review briefly discusses their use in nanomedicine, cancer treatment, treatment of other diseases, tissue repair, catalysis and applications in OLEDs and solar cells.


2021 ◽  
Vol 244 ◽  
pp. 117955
Author(s):  
Mohamed S. Hamdy ◽  
Badria M. Al-Shehri ◽  
Murad Eissa ◽  
Fahad A. Alharthi ◽  
Abdulaziz Ali Alghamdi ◽  
...  

2014 ◽  
Vol 20 (S3) ◽  
pp. 60-61
Author(s):  
Lewys Jones ◽  
Vidar T. Fauske ◽  
Katherine E. MacArthur ◽  
Antonius T. J. van Helvoort ◽  
Peter D. Nellist

1979 ◽  
Vol 30 (12) ◽  
pp. 767-770 ◽  
Author(s):  
T.T. Tsong ◽  
John Sweeney

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