scholarly journals Driving useful morphological changes in magnetic nanoparticle structures through the application of acoustic waves and magnetic fields

2018 ◽  
Vol 113 (3) ◽  
pp. 034103 ◽  
Author(s):  
An Huang ◽  
Morteza Miansari ◽  
James Friend
Keyword(s):  
Magnetic Fields ◽  
Acoustic Waves ◽  
Magnetic Nanoparticle ◽  
Morphological Changes

scholarly journals Inactivation of Bacteria Using Bioactive Nanoparticles and Alternating Magnetic Fields

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 342
Author(s):  
Vitalij Novickij ◽  
Ramunė Stanevičienė ◽  
Rūta Gruškienė ◽  
Kazimieras Badokas ◽  
Juliana Lukša ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Foodborne Pathogens ◽  
Morphological Changes ◽  
Foodborne Pathogen ◽  
Cellular Damage ◽  
Suitable Model ◽  
Log Reduction ◽  
Invasive Infections ◽  
Alternating Magnetic Fields ◽  
Inactivation Of Bacteria

Foodborne pathogens are frequently associated with risks and outbreaks of many diseases; therefore, food safety and processing remain a priority to control and minimize these risks. In this work, nisin-loaded magnetic nanoparticles were used and activated by alternating 10 and 125 mT (peak to peak) magnetic fields (AMFs) for biocontrol of bacteria Listeria innocua, a suitable model to study the inactivation of common foodborne pathogen L. monocytogenes. It was shown that L. innocua features high resistance to nisin-based bioactive nanoparticles, however, application of AMFs (15 and 30 min exposure) significantly potentiates the treatment resulting in considerable log reduction of viable cells. The morphological changes and the resulting cellular damage, which was induced by the synergistic treatment, was confirmed using scanning electron microscopy. The thermal effects were also estimated in the study. The results are useful for the development of new methods for treatment of the drug-resistant foodborne pathogens to minimize the risks of invasive infections. The proposed methodology is a contactless alternative to the currently established pulsed-electric field-based treatment in food processing.

scholarly journals Short-Term Spectral Variability in the Herbig Ae Star Ab Aur: Preliminary Analysis of Chromospheric Lines

1993 ◽  
Vol 137 ◽  
pp. 665-668
Author(s):  
Torsten Böhm ◽  
Claude Catala
Keyword(s):  
Magnetic Fields ◽  
Acoustic Waves ◽  
Main Sequence ◽  
Main Question ◽  
Spectral Variability ◽  
Surface Magnetic Field ◽  
External Agent ◽  
Static Contraction ◽  
Magnetic Origin ◽  
Herbig Ae Stars

The Herbig Ae stars are PMS objects of intermediate mass. Their location in the H-R diagram indicates that they are in the radiative phase of their quasi-static contraction toward the main sequence, i.e. that they do not possess outer convective zones, according to the standard stellar evolution theory (Iben, 1965; Gilliland, 1986). In spite of the expected absence of subphotospheric convective envelopes, these stars show remarkable signs of activity: emission in the Mg II h and k lines, presence of the CIV resonance lines at 1550 A and He I 5875.7 A line, Ca II IR triplet in emission, etc... Considering that stellar activity, witnessed by the same type of indicators in other parts of the H-R diagram, is generally attributed to dynamo magnetic fields and/or acoustic waves generated in the convection zone, these active phenomena are quite paradoxical in the Herbig Ae stars.The main question concerns the origin of their activity: is this activity linked to phenomena occurring within the stars, like e.g. dynamo-generated magnetic fields, or to an external agent, like e.g. a boundary layer between an accretion disk and the stellar surface? We already have some indirect clues that the activity of the Herbig Ae stars might be of magnetic origin (Praderie et al., 1986; Catala et al. 1986) observed a rotational modulation of lines formed in the wind of AB Aur, prototype of the Herbig Ae stars. By analogy with the solar wind, they proposed that the modulation might be due to the corotation of azimuthal structures in the wind, controlled by a surface magnetic field.

scholarly journals Enhancing cellular morphological changes and ablation of cancer cells via the interaction of drug co-loaded magnetic nanosystems in weak rotating magnetic fields

RSC Advances ◽  
2020 ◽  
Vol 10 (25) ◽  
pp. 14471-14481
Author(s):  
Tingting Wu ◽  
Qian Zhang ◽  
Huiping Hu ◽  
Fang Yang ◽  
Ke Li ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Cancer Cells ◽  
Morphological Changes ◽  
Rotating Magnetic Fields ◽  
Rotational Movement ◽  
Apoptotic Effect

Tetrandrine and Fe3O4 nanoparticle co-loaded PLGA nanosystems produce rotational movement and promote tetrandrine release, causing a dual apoptotic effect to tumors.

Magnetic coupling of waves and oscillations in the lower solar atmosphere: can the tail wag the dog?

2005 ◽  
Vol 364 (1839) ◽  
pp. 351-381 ◽  
Author(s):  
Robert Erdélyi
Keyword(s):  
Magnetic Fields ◽  
Solar Atmosphere ◽  
Acoustic Waves ◽  
Large Scale ◽  
Magnetic Coupling ◽  
Small Scale ◽  
Coupling Mechanism ◽  
Frequency Shifts ◽  
Characteristic Features ◽  
Lower Solar Atmosphere

Can the ubiquitously magnetic solar atmosphere have any effect on solar global oscillations? Traditionally, solar atmospheric magnetic fields are considered to be somewhat less important for the existence and characteristic features of solar global oscillations ( p , f and the not-yet-observed g -modes). In this paper, I demonstrate the importance of the presence of magnetism and plasma dynamics for global resonant oscillations in the solar atmosphere. In particular, in the lower part of the solar atmosphere there are both coherent and random components of magnetic fields and velocity fields, each of which contribute on its own to the line widths and frequency variations of solar global acoustic waves. Changes in the coherent large-scale atmospheric magnetic fields cause frequency shifts of global oscillations over a solar cycle. The random character of the continuously emerging, more localized, magnetic carpet (i.e. small-scale, possibly even sub-resolution, loops) gives rise to additional frequency shifts. On the other hand, random and organized surface and sub-surface flows, like surface granulation, meridional flows or differential rotation, also affect the coupling mechanism of global oscillations to the lower magnetic atmosphere. The competition between magnetic fields and flows is inevitable. Finally, I shall discuss how solar global oscillations can resonantly interact with the overlaying inhomogeneous lower solar atmosphere embedded in a magnetic carpet. Line width broadening and distorsion of global acoustic modes will be discussed. The latter is suggested to be tested and measured by using ring-analysis techniques.

Suppression of the photoluminescence quenching due to surface acoustic waves in high magnetic fields

2002 ◽  
Vol 17 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Y Takagaki ◽  
E Wiebicke ◽  
H J Zhu ◽  
R Hey ◽  
M Ramsteiner ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
High Magnetic Fields ◽  
Photoluminescence Quenching

The structural and organic magnetoresistance response of poly(9-vinyl carbazole) using low applied magnetic fields and magnetic nanoparticle addition

2017 ◽  
Vol 5 (15) ◽  
pp. 3779-3787 ◽  
Author(s):  
Mariano Romero ◽  
Ricardo Faccio ◽  
Milton A. Tumelero ◽  
André A. Pasa ◽  
Alvaro W. Mombrú
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Fields ◽  
Magnetic Nanoparticle ◽  
Structural Modifications ◽  
Organic Magnetoresistance

Evidence of PVK singlet-to-triplet and structural modifications are revealed with the addition of magnetic nanoparticles and low applied magnetic fields.

scholarly journals Physics of magnetized dusty plasmas

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Andre Melzer ◽  
H. Krüger ◽  
D. Maier ◽  
S. Schütt
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Dusty Plasma ◽  
Acoustic Waves ◽  
Dusty Plasmas ◽  
Plasma Properties ◽  
Fundamental Parameters ◽  
Wake Field ◽  
Magnetized Dusty Plasma ◽  
Dust Component

AbstractIn this review, we summarize recent advances in the field of dusty plasmas at strong magnetic fields. Special emphasis is put on situations where experimental laboratory observations are available. These generally comprise dusty plasmas with magnetized electrons and ions, but unmagnetized dust. The fundamental parameters characterizing a magnetized (dusty) plasma are given and various effects in dusty plasmas under magnetic fields are presented. As examples, the reaction of the dust component to magnetic-field modified plasma properties, such as filamentation, imposed structures, dust rotation, nanodusty plasmas and the resulting forces on the dust are discussed. Further, the behavior of the dust charge is described and shown to be relatively unaffected by magnetic fields. Wake field formation in magnetized discharges is illustrated: the strength of the wake field is found to be reduced with increased magnetic field. The propagation of dust acoustic waves in magnetized dusty plasmas is experimentally measured and analyzed indicating that the wave dynamics are not heavily influenced by the magnetic field. Only at the highest fields ($$B> 1$$ B > 1  T) the wave activity is found to be reduced. Moreover, it is discussed how dust-cyclotron waves might be used to indicate a magnetized dust component. Finally, implications of a magnetized dusty plasma are illustrated.

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