Numerical Simulation Study for the Effect of the Strength and the Direction of a Static Magnetic Field on the Transient Double-Diffusive Flow in Liquid Phase during an Alloy Solidification

2010 ◽  
Vol 297-301 ◽  
pp. 97-104 ◽  
Author(s):  
Farid Mechighel ◽  
Bernard Pateyron ◽  
Mahfoud Kadja ◽  
Mohammed El Ganaoui ◽  
S. Dost
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Static Magnetic Field ◽  
Simulation Study ◽  
Solidification Process ◽  
Magnetic Field Effects ◽  
Charge Balance ◽  
Diffusive Flow ◽  
Volume Method ◽  
Double Diffusive

A numerical simulation study has been carried out to examine the effect of a static magnetic field on the solidification process of an alloy. A mathematical model, based on the continuum model, was developed for the computation of a transient double-diffusive fluid flow under Lorentz body force. The model includes conservation of mass and momentum, heat, species and electrical charge balance equations. The simulation domain was selected as a cavity filled with a metallic alloy and differentially heated, which may be taken as a Bridgman model domain used in the crystal growth process. The solution is carried out by using a Finite Volume Method. Study of the direction and the intensity of the applied magnetic field effects on stabilizing the double diffusive flow field were also carried out. Simulation results indicate that the use of a static, magnetic field in this growth setup is effective in suppressing natural convection in the solution.

A Numerical Simulation Study on the Effects of Crucible Rotation and Magnetic Fields in Growth of SiGe by the Traveling Heater Method

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Youhei Takagi ◽  
Yasunori Okano ◽  
Sadik Dost
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Static Magnetic Field ◽  
Simulation Study ◽  
Concentration Field ◽  
Magnetic Field Direction ◽  
Simultaneous Application ◽  
Rotation Rates ◽  
Traveling Heater Method ◽  
Crucible Rotation

A numerical simulation study was carried out to shed light on the effects of applied crucible rotation and static magnetic field during the traveling heater method growth of bulk SiGe single crystals. The simulation results show that the application of crucible rotation weakens the radial silicon concentration gradient due to the effect of centrifugal force. The effects of applied static magnetic field direction and strength on the concentration field in the melt were also studied. It was found that the simultaneous application of crucible rotation and static magnetic field is best to grow large crystals with uniform composition. An optimum combination of crucible rotation rates and applied magnetic field strengths is determined.

A Numerical Simulation Study on the Effects of Crucible Rotation and Magnetic Fields in Growth of SiGe by the Travelling Heater Method

2010 ◽  
Author(s):  
Youhei Takagi ◽  
Atsuko Ishida ◽  
Yasunori Okano ◽  
Sadik Dost
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Static Magnetic Field ◽  
Simulation Study ◽  
Concentration Field ◽  
Magnetic Field Direction ◽  
Simultaneous Application ◽  
Rotation Rates ◽  
Crucible Rotation ◽  
Shed Light

A numerical simulation study was carried out to shed light on the effects of applied crucible rotation and static magnetic field during the THM (travelling heater method) growth of bulk SiGe single crystals. The simulation results show that the application of crucible rotation weakens the radial silicon concentration gradient due to the effect of centrifugal force. The effects of applied static magnetic field direction and strength on the concentration field in the melt were also studied. It was found that the simultaneous application of crucible rotation and static magnetic field is best to grow large crystals with uniform composition. An optimum combination of crucible rotation rates and applied magnetic field strengths is determined.

Geomagnetic and strong static magnetic field effects on growth and chlorophyllafluorescence inLemna minor

2015 ◽  
Vol 36 (3) ◽  
pp. 190-203 ◽  
Author(s):  
Luka Jan ◽  
Dušan Fefer ◽  
Katarina Košmelj ◽  
Alenka Gaberščik ◽  
Igor Jerman
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Magnetic Field Effects ◽  
Field Effects

scholarly journals Novel static magnetic field effects on green chemistry biosynthesis of silver nanoparticles in Saccharomyces cerevisiae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ameni Kthiri ◽  
Selma Hamimed ◽  
Abdelhak Othmani ◽  
Ahmed Landoulsi ◽  
Siobhan O’Sullivan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Saccharomyces Cerevisiae ◽  
Silver Nanoparticles ◽  
Magnetic Fields ◽  
Green Chemistry ◽  
Static Magnetic Field ◽  
Culture Medium ◽  
Average Diameter ◽  
Magnetic Field Effects ◽  
Static Magnetic Fields

AbstractThe bacteriocidal properties of silver nanoparticles (AgNPs) depend on their average diameter (toxicity increases with decreasing diameter). In the present work, we describe novel green chemistry biosynthesis of AgNPs from AgNO3 added to cell-free culture medium of baker’s yeast, Saccharomyces cerevisiae, yielding nanoparticles in the range 11–25 nm. However, when yeast was grown in a moderate static magnetic field, AgNPs obtained from the resulting cell-free culture medium, were significantly smaller (2–12 nm) than those obtained without magnetic field. These latter nanoparticles were highly crystalline, stable and near-uniform shape. Furthermore, the antibacterial activity of AgNPs obtained from static magnetic fields were greater than those from control cultures. Static magnetic fields show a promising ability to generate biocidal nanoparticles via this novel green chemistry approach.

Polarized Induced Magnetic Broadening of Photonic Activities in Fe3O4-Elastomer Composites

2013 ◽  
Vol 1509 ◽  
Author(s):  
Danhao Ma ◽  
Dustin T. Hess ◽  
Pralav P Shetty ◽  
Kofi W. Adu ◽  
Richard Bell ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Static Magnetic Field ◽  
Electric Dipole ◽  
Composite Films ◽  
Optical Response ◽  
Silicone Elastomer ◽  
Magnetic Field Effects ◽  
Out Of Plane

AbstractWe report a systematic study of polarization and magnetic field effects on the optical response of Fe3O4-silicone elastomer composite. The Fe3O4 particles were aligned in a silicone elastomer matrix with an external static magnetic field. Films of composites containing 5wt% of 20nm ≤ d ≤ 30nm Fe3O4 particles aligned in- and out-of-plane in the elastomer host were prepared. The optical spectra of the films were measured with the Perkin-Elmer Lambda 950 UV/vis/NIR spectrometer. We observed a systematic redshift in the optical response of the outof-plane composite films with increasing static magnetic field strength, which saturated near 600 Gauss. We obtained a maximum redshift of ∼46 nm at 600 Gauss. The observed redshift in the optical response of the out-of-plane composite film is attributed to the effect of the magnetic field. This facilitated the formation of the highly aligned particles that induced strong electric dipole in the aligned particles. Interestingly, there were no observable shifts with increasing magnetic field strength in the in-plane films, suggesting that the orientation (polarization) of the magnetic dipole and the induced electric dipole play a crucial role in the optical response.

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