scholarly journals Laser Heating of the Core-Shell Nanowires

2016 ◽  
Vol 59 (1) ◽  
pp. 2-12
Author(s):  
Iordana Astefanoaei ◽  
Ioan Dumitru ◽  
Alexandru Stancu
Keyword(s):  
Laser Heating ◽  
Thermal Characteristics ◽  
Spot Size ◽  
Magnetic Core ◽  
Internal Stresses ◽  
Heating Process ◽  
Core Shell ◽  
Heating Source ◽  
Beam Parameters ◽  
Shell Nanowires

AbstractThe induced thermal stress in a heating process is an important parameter to be known and controlled in the magnetization process of core-shell nanowires. This paper analyses the stress produced by a laser heating source placed at one end of a core-shell type structure. The thermal field was computed with the non-Fourier heat transport equation using a finite element method (FEM) implemented in Comsol Multiphysics. The internal stresses are essentially due to thermal gradients and different expansion characteristics of core and shell materials. The stress values were computed using the thermo elastic formalism and are depending on the laser beam parameters (spot size, power etc.) and system characteristics (dimensions, thermal characteristics). Stresses in the GPa range were estimated and consequently we find that the magnetic state of the system can be influenced significantly. A shell material as the glass which is a good thermal insulator induces in the magnetic core, the smaller stresses and consequently the smaller magnetoelastic energy. These results lead to a better understanding of the switching process in the magnetic materials.

scholarly journals Magnetic core–shell nanowires as MRI contrast agents for cell tracking

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Aldo Isaac Martínez-Banderas ◽  
Antonio Aires ◽  
Sandra Plaza-García ◽  
Lorena Colás ◽  
Julián A. Moreno ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Cell Tracking ◽  
Magnetic Core ◽  
Mri Contrast Agents ◽  
Core Shell ◽  
Mri Contrast ◽  
Shell Nanowires

Modeling Laser Heating for Roller Hemming Applications

2011 ◽  
Vol 473 ◽  
pp. 501-508 ◽  
Author(s):  
Tobias Kleeh ◽  
Marion Merklein ◽  
Karl Roll
Keyword(s):  
Laser Heating ◽  
Elevated Temperatures ◽  
Fuel Efficiency ◽  
Element Model ◽  
Process Window ◽  
Heating Process ◽  
New Approach ◽  
Heating Source ◽  
The Subject ◽  
Set Up

In order to improve fuel efficiency, the use of lightweight materials in the automotive industry is continuously increasing. The AA6XXX and AA7XXX aluminum alloys in particular are the subject of significant attention. The aim is to use them in the same way as other structural materials such as conventional steel. Unfortunately their formability presents major challenges. These alloys lack sufficient formability for bending/hemming operations in particular. To overcome this, forming can take place at elevated temperatures. In this study, a combined laser-assisted roller hemming process is set up. Therefore, a 4000 W Nd:YAG-laser with a wavelength of 1096 nm is used. The first step involves qualifying the process window for laser heating. Several parameters are defined and effects on temperature and surface quality for AA6014 are detected using the design of experiments. The second step involves setting up a finite element model of the heating process. Different modeling strategies for laser heating are compared and a new approach is presented. The laser heating source is modeled by a semi-circular Gaussian temperature distribution and is validated through comparison of the temperature with laser heating experiments, showing very good agreement in the range from 600-4000 W. Finally, the validated thermal model is coupled with the roller hemming simulation and investigations into the thermal process window are performed.

Magnetic behavior of Joule-heated magnetic core–shell nanowires with positive magnetostrictive core material

2015 ◽  
Vol 352 ◽  
pp. 54-59
Author(s):  
Ioan Dumitru ◽  
Iordana Astefanoaei ◽  
Dorin Cimpoesu ◽  
Alexandru Stancu
Keyword(s):  
Magnetic Behavior ◽  
Magnetic Core ◽  
Core Material ◽  
Core Shell ◽  
Shell Nanowires

scholarly journals Electrochemical preparation and characterization of magnetic core–shell nanowires for biomedical applications

2016 ◽  
Vol 63 ◽  
pp. 18-21 ◽  
Author(s):  
C. Gispert ◽  
A. Serrà ◽  
M.E. Alea ◽  
M. Rodrigues ◽  
E. Gómez ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Magnetic Core ◽  
Core Shell ◽  
Electrochemical Preparation ◽  
Shell Nanowires

scholarly journals Synthesis and magnetic properties of cobalt-iron/cobalt-ferrite soft/hard magnetic core/shell nanowires

2017 ◽  
Vol 28 (24) ◽  
pp. 245605 ◽  
Author(s):  
César Leandro Londoño-Calderón ◽  
Oscar Moscoso-Londoño ◽  
Diego Muraca ◽  
Luis Arzuza ◽  
Peterson Carvalho ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Cobalt Ferrite ◽  
Magnetic Core ◽  
Core Shell ◽  
Iron Cobalt ◽  
Cobalt Iron ◽  
Shell Nanowires

One-Dimensional TiO2@GaON Core-Shell Nanowires with Controlled Shell Thickness from Atomic Layer Deposition for Stable and Efficient Photoelectrochemical Water Splitting

2019 ◽  
Author(s):  
Jiajia Tao ◽  
Hong-Ping Ma ◽  
Kaiping Yuan ◽  
Yang Gu ◽  
Jianwei Lian ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Band Gap ◽  
Water Splitting ◽  
Atomic Layer ◽  
Photoelectrochemical Water Splitting ◽  
Core Shell ◽  
Photoelectrochemical Performance ◽  
Highly Efficient ◽  
Layer Deposition ◽  
Shell Nanowires

<div>As a promising oxygen evolution reaction semiconductor, TiO2 has been extensively investigated for solar photoelectrochemical water splitting. Here, a highly efficient and stable strategy for rationally preparing GaON cocatalysts on TiO2 by atomic layer deposition is demonstrated, which we show significantly enhances the</div><div>photoelectrochemical performance compared to TiO2-based photoanodes. For TiO2@20 nm-GaON core-shell nanowires a photocurrent density up to 1.10 mA cm-2 (1.23 V vs RHE) under AM 1.5 G irradiation (100 mW cm-2) has been achieved, which is 14 times higher than that of TiO2 NWs. Furthermore, the oxygen vacancy formation on GaON as well as the band gap matching with TiO2 not only provides more active sites for water oxidation but also enhances light absorption to promote interfacial charge separation and migration. Density functional theory studies of model systems of GaON-modified TiO2 confirm the band gap reduction, high reducibility and ability to activate water. The highly efficient and stable systems of TiO2@GaON core-shell nanowires provide a deeper understanding and universal strategy for enhancing photoelectrochemical performance of photoanodes now available. </div>

scholarly journals Broadband Meta‐Absorber with Au/Ni Core–Shell Nanowires for Solar Vapor Generator

2021 ◽  
Vol 5 (7) ◽  
pp. 2100185
Author(s):  
Soomin Son ◽  
Jaemin Park ◽  
Sucheol Ju ◽  
Daihong Huh ◽  
Junho Jun ◽  
...  
Keyword(s):  
Core Shell ◽  
Vapor Generator ◽  
Shell Nanowires

scholarly journals Fabrication of copper(II)-coated magnetic core-shell nanoparticles Fe3O4@SiO2-2-aminobenzohydrazide and investigation of its catalytic application in the synthesis of 1,2,3-triazole compounds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Rajabi-Moghaddam ◽  
M. R. Naimi-Jamal ◽  
M. Tajbakhsh
Keyword(s):  
High Efficiency ◽  
Click Reaction ◽  
Magnetic Core ◽  
Core Shell ◽  
Isatoic Anhydride ◽  
Shell Nanoparticles ◽  
Triazole Derivatives ◽  
Catalytic Application ◽  
Ft Ir ◽  
Core Shell Nanoparticles

AbstractIn the present work, an attempt has been made to synthesize the 1,2,3-triazole derivatives resulting from the click reaction, in a mild and green environment using the new copper(II)-coated magnetic core–shell nanoparticles Fe3O4@SiO2 modified by isatoic anhydride. The structure of the catalyst has been determined by XRD, FE-SEM, TGA, VSM, EDS, and FT-IR analyzes. The high efficiency and the ability to be recovered and reused for at least up to 6 consecutive runs are some superior properties of the catalyst.

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