scholarly journals Sizing and Eddy currents in magnetic core nanoparticles: an optical extinction approach

2017 ◽  
Vol 19 (4) ◽  
pp. 3076-3083 ◽  
Author(s):  
Luis J. Mendoza Herrera ◽  
Ignacio J. Bruvera ◽  
Lucía B. Scaffardi ◽  
Daniel C. Schinca
Keyword(s):  
Size Distribution ◽  
Eddy Currents ◽  
Extinction Spectrum ◽  
Mie Theory ◽  
Magnetic Core ◽  
Frequency Dependent ◽  
Optical Extinction ◽  
Coating Layers ◽  
Core Nanoparticles

We extend the typical analysis of the extinction spectrum of magnetic core NPs by solving Mie theory with a frequency dependent susceptibility and considering the effect of Eddy currents in order to obtain the size distribution of the cores and the coating layers.

Nonlinear Frequency-Dependent Model for Microinductors With Magnetic Core

2013 ◽  
Vol 34 (2) ◽  
pp. 304-306 ◽  
Author(s):  
Steven Gaskill ◽  
Andrei Papou ◽  
Anuraag Mohan ◽  
William French ◽  
Andreas Weisshaar
Keyword(s):  
Magnetic Core ◽  
Nonlinear Frequency ◽  
Frequency Dependent ◽  
Dependent Model ◽  
Frequency Dependent Model

scholarly journals Picoliter Cuvette inside an Optical Fiber to Track Gold Nanoparticle Aggregation for Measurement of Biomolecules

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2859
Author(s):  
Masahiko Shiraishi ◽  
Kazuhiro Watanabe ◽  
Shoichi Kubodera
Keyword(s):  
Optical Fiber ◽  
Gold Nanoparticle ◽  
Extinction Spectrum ◽  
Optical Path Length ◽  
Optical Extinction ◽  
Near Ultraviolet ◽  
Measurement Resolution ◽  
Simple Measurement ◽  
The Difference ◽  
Dispersion Solution

This study demonstrated a measurement approach for biomolecules at the picoliter scale, using a newly developed picoliter cuvette inside an optical fiber constructed via near-ultraviolet femtosecond laser drilling. The sensing capacity was estimated to be within 0.4–1.2 pL due to an optical path length of 3–5 microns, as measured by scanning electron microscopy (SEM). The picoliter cuvette exhibited a change in the optical extinction spectrum after addition of biomolecules such as L-cysteine, in conjunction with a gold nanoparticle (GNP) dispersion solution, following a simple measurement configuration involving a small white light source and a compact spectrometer. A linear attenuation of the spectral dip near a wavelength of 520 nm was observed as the L-cysteine concentration was increased at 4 wt% of the GNP mass concentration. The measurement resolution of the concentration using the picoliter cuvette was evaluated at 0.125 mM. The experimental results showed the difference in aggregation processes caused by a different concentration of GNPs. Moreover, they revealed the ability of the picoliter cuvette to verify whether the concentration of GNPs in the liquid sample correspondingly determines homogeneous or inhomogeneous GNP aggregation, as supported by SEM observation and numerical calculations based on Mie theory.

Reconstructed expression for aerosol extinction coefficient by considering mass extinction efficiency and hygroscopic growth for polydipersed aerosol

2020 ◽  
Author(s):  
Chang Hoon Jung ◽  
JiYi Lee ◽  
Junshik Um ◽  
Yong Pyo Kim
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Growth Factor ◽  
Size Distribution ◽  
Enhancement Factor ◽  
Size Range ◽  
Geometric Mean ◽  
Mie Theory ◽  
Hygroscopic Growth ◽  
Particle Size Range

<p>In this study, simplified analytic type of expression for size dependent MEs (Mass efficiencies) are developed. The entire size was considered assuming lognormal size distribution for sulfate, nitrate and NaCl aerosol species and the MEE of each aerosol chemical composition was estimated by fitting Mie’s calculation. The obtained results are compared with the results from the Mie-theory-based calculations and showed comparable results.</p><p>The mass efficiencies of all aerosol components for each size range are compared with Mie’s results and approximated as a function of geometric mean diameter in the form of a power law formula. Finally, harmonic mean type approximation was used to cover entire particle size range.</p><p>Also, analytic expression of approximated scattering enhancement factor which stands for the effect of hygroscopic growth factor for polydispersed aerosol on aerosol optical properties are obtained.</p><p>Based on aerosol thermodynamic models, mass growth factor can be obtained and their optical properties can be obtained by using Mie theory with different aerosol properties and size distribution. Finally, scattering enhancement factor was approximated fRH for polydispersed aerosol as a function of RH.</p><p>Finally, we also compared the simple forcing efficiency (SFE, W/g) of polydisperse aerosols between the developed simple approach and by the method using the Mie theory. The results show that current obtained approximated methods are comparable with existing numercal calculation based results for polydipersed particle size.</p>

Determination of the size distribution of metallic nanoparticles by optical extinction spectroscopy

2009 ◽  
Vol 48 (3) ◽  
pp. 566 ◽  
Author(s):  
Ovidio Peña ◽  
Luis Rodríguez-Fernández ◽  
Vladimir Rodríguez-Iglesias ◽  
Guinther Kellermann ◽  
Alejandro Crespo-Sosa ◽  
...  
Keyword(s):  
Size Distribution ◽  
Metallic Nanoparticles ◽  
Optical Extinction ◽  
Optical Extinction Spectroscopy

scholarly journals Dynamic magnetic characterization and magnetic particle imaging enhancement of magnetic-gold core–shell nanoparticles

Nanoscale ◽  
2019 ◽  
Vol 11 (13) ◽  
pp. 6489-6496 ◽  
Author(s):  
Asahi Tomitaka ◽  
Satoshi Ota ◽  
Kizuku Nishimoto ◽  
Hamed Arami ◽  
Yasushi Takemura ◽  
...  
Keyword(s):  
Magnetic Particle ◽  
Magnetic Core ◽  
Gold Coating ◽  
Shell Nanoparticles ◽  
Gold Core ◽  
Magnetic Particle Imaging ◽  
Particle Imaging ◽  
Core Shell Nanoparticles ◽  
Imaging Performance ◽  
Core Nanoparticles

The gold coating on magnetic core nanoparticles enhanced magnetic particle imaging performance due to an alteration in dynamic magnetic responses.

scholarly journals High spectral field enhancement and tunability in core–double shell metal–dielectric–metal spherical nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (112) ◽  
pp. 110471-110481 ◽  
Author(s):  
Luis J. Mendoza Herrera ◽  
Lucía B. Scaffardi ◽  
Daniel C. Schinca
Keyword(s):  
External Factor ◽  
Mie Theory ◽  
Field Enhancement ◽  
Spherical Nanoparticles ◽  
Optical Extinction ◽  
Plasmon Resonances ◽  
Spherical Core

Full Mie theory for spherical core–double shell NPs has been developed to study plasmon resonances, optical extinction and spectral field enhancement of a generalized metal–dielectric–metal NPs, reaching an external factor of 33 for Al–SiO2–Au.

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