• Title/Summary/Keyword: magnetic oxide

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Water carrying iron (iii) oxide (Fe3O4) ferrofluid flow and heat transfer due to deceleration of a rotating plate

  • Bhandari, Anupam
    • Structural Engineering and Mechanics
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    • v.82 no.5
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    • pp.679-690
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    • 2022
  • This research effort examines the flow behavior and heat transfer assessment of water carrying iron (iii) oxide magnetic fluid due to a rotating and moving plane lamina under the influence of magnetic dipole. The effect of rotational viscosity and magnetic body force is taken into consideration in the present study. The involvement of the moving disk makes a significant contribution to the velocity distribution and heat transfer in rotational flow. Vertical movement of the disk keeps the flow unsteady and the similarity transformation converts the governing equation of unsteady flow into nonlinear coupled differential equations. The non-dimensional equation in the present system is solved through the finite element procedure. Optimizing the use of physical parameters described in this flow, such results can be useful in the rotating machinery industries for heat transfer enhancement.

Critical Enhancement of Photothermal Effect by Integrated Nanocomposites of Gold Nanorods and Iron Oxide on Graphene Oxide

  • Yun, Kum-Hee;Seo, Sun-Hwa;Kim, Bo-Mi;Joe, Ara;Han, Hyo-Won;Kim, Jong-Young;Jang, Eue-Soon
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2795-2799
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    • 2013
  • Irradiation of gold nanorods (GNRs) with laser light corresponding to the longitudinal surface plasmon oscillation results in rapid conversion of electromagnetic energy into heat, a phenomenon commonly known as the photothermal effect of GNRs. Herein, we propose a facile strategy for increasing the photothermal conversion efficiency of GNRs by integration to form graphene oxide (GO) nanocomposites. Moreover, conjugation of iron oxide (IO) with the GO-GNR nanohybrid allowed magnetic enrichment at a specific target site and the separated GO-IO-GNR assembly was rapidly heated by laser irradiation. The present GO-IO-GNR nanocomposites hold great promise for application in various biomedical fields, including surface enhanced Raman spectroscopy imaging, photoacoustic tomography imaging, magnetic resonance imaging, and photothermal cancer therapy.

Development of DNA Sensor Using Magnetic Iron Oxide Nanoparticle (자성 산화철(iron oxide) 나노입자를 이용한 DNA 센서 개발)

  • Nam, Ki-Chang;Song, Kwang-Soup
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.6
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    • pp.51-56
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    • 2011
  • The surface of magnetic iron oxide nanoparticles (${\gamma}-Fe_2O_3$) is functionalized ($-NH_2$, -COOH) with bifunctional organic molecules and evaluated using FT-IR (Fourier transform infrared spectroscopy). We immobilize 21-base pair probe DNA and hybridize fluorescence-labeled (Cy5) target DNA onto the functionalized iron oxide nanoparticles. The fluorescence images obtained from a confocal microscopy show that the functionalized iron oxide nanoparticles should detect the hybridization of complementary and noncomplementary DNA.

Large-scale Synthesis of Uniform-sized Nanoparticles for Multifunctional Medical Applications

  • Hyeon, Taeg-Hwan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.1-1
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    • 2011
  • We developed a new generalized synthetic procedure, called as "heat-up process," to produce uniform-sized nanocrystals of many transition metals and oxides without a size selection process. We were able to synthesize uniform magnetite nanocrystals as much as 1 kilogram-scale from the thermolysis of Fe-oleate complex. Clever combination of different nanoscale materials will lead to the development of multifunctional nano-biomedical platforms for simultaneous targeted delivery, fast diagnosis, and efficient therapy. In this presentation, I would like to present some of our group's recent results on the designed fabrication of multifunctional nanostructured materials based on uniform-sized magnetite nanoparticles and their medical applications. Uniform ultrasmall iron oxide nanoparticles of <3 nm were synthesized by thermal decomposition of iron-oleate complex in the presence of oleyl alcohol. These ultrasmall iron oxide nanoparticles exhibited good T1 contrast effect. In in vivo T1 weighted blood pool magnetic resonance imaging (MRI), iron oxide nanoparticles showed longer circulation time than commercial gadolinium complex, enabling high resolution imaging. We used 80 nm-sized ferrimagnetic iron oxide nanocrystals for T2 MRI contrast agent for tracking transplanted pancreatic islet cells and single-cell MR imaging. We reported on the fabrication of monodisperse magnetite nanoparticles immobilized with uniform pore-sized mesoporous silica spheres for simultaneous MRI, fluorescence imaging, and drug delivery. We synthesized hollow magnetite nanocapsules and used them for both the MRI contrast agent and magnetic guided drug delivery vehicle.

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