19 Result(s)

Article

Power control strategy for preventing thermal failure of passively cooled automotive battery packs

Safety mechanism is required for an automotive battery pack to prevent thermal failure which could lead to catastrophic events. Passively cooled battery packs can prevent thermal failure by conducting adaptive...

S. Jung, S. H. Park, B. C. Choi in International Journal of Automotive Technology (2017)

Article

Effects of DME mixing on number density and size properties of soot particles in counterflow non-premixed ethylene flames

In order to investigate the effect of DME mixing on the number density and size of soot particles, DME was mixed in a counter flow non-premixed ethylene flame with mixture ratios of 5%, 14% and 30%. A laser ex...

J. H. Choi, B. C. Choi, S. M. Lee… in Journal of Mechanical Science and Technolo… (2015)

Article

Structural, optical, and magnetic properties of single-crystalline Mn₃O₄ nanowires

We report a simple and effective method to synthesize single-crystalline Mn₃O₄ nanowires using solvothermal technique. These nanowires with diameter in the range 15–40 nm grow uniformly along {2 0 0} direction an...

S. Sambasivam, G. J. Li, J. H. Jeong, B. C. Choi… in Journal of Nanoparticle Research (2012)

Article

Major sources of hydrocarbon emissions in a premixed charge compression ignition engine

Although premixed charge compression ignition (PCCI) combustion engines are praised for potentially high efficiency and clean exhaust, experimental engines built to date emit more hydrocarbons (HCs) and carbon...

G. S. Jung, Y. H. Sung, B. C. Choi… in International Journal of Automotive Techno… (2012)

Article

Ferroelectric properties of Zn- and Ti-doped BiFeO₃ thin films

BiFeO₃ (BFO), Ti-doped BFO (BFTO), and Zn-doped BFO (BFZO) thin films were deposited on Pt(111)/Ti/SiO₂/Si(100) substrates by using a pulsed laser deposition method. The effects of the substitution of Zn and Ti w...

M. H. Lee, J. S. Park, H. J. Cho, D. J. Kim… in Journal of the Korean Physical Society (2012)

Article

Experimental and numerical investigation of fuel mixing effects on soot structures in counterflow diffusion flames

Experimental and numerical analyses of laminar diffusion flames were performed to identify the effect of fuel mixing on soot formation in a counterflow burner. In this experiment, the volume fraction, number d...

B. C. Choi, S. K. Choi, S. H. Chung… in International Journal of Automotive Techno… (2011)

Article

Ultrafast Magnetization Reversal Dynamics on a Micrometer-Scale Thin Film Element Studied by Time Domain Imaging

Picosecond time scale magnetization reversal dynamics in a 15nm thick Ni₈₀Fe₂₀ microstructure (10μm×2μm) is studied using time-resolved scanning Kerr microscopy. The time domain images reveal a striking change in...

B. C. Choi, G. Ballentine, M. Belov, W. K. Hiebert… in MRS Online Proceedings Library (2011)

Chapter

CMOS-based Spin-Transfer Torque Magnetic Random Access Memory (ST–MRAM)

Recently it has been demonstrated that the vortex core magnetization can be switched by applying a short (<100 ps) magnetic field pulse. This is an important step towards utilizing the two stable states of the...

B. C. Choi, Y. K. Hong, A. Lyle, G. W. Donohoe in CMOS Processors and Memories (2010)

Article

Synthesis and characterization of CoFe₂O₄–Ba_0.9Sr_0.1TiO₃ magnetoelectric composites with dielectric and magnetic properties

Magnetoelectric composites of CoFe₂O₄ ferrite (CFO) and 10 mole % strontium doped BaTiO₃ (BSTO) were synthesized by the solid state reaction method. The presence of two phases in the composite (x)CoFe₂O₄+(1−x)Ba_0...

C. M. Kanamadi, J. S. Kim, H. K. Yang, B. K. Moon, B. C. Choi… in Applied Physics A (2009)

Article

Effects of mixture stratification on HCCI combustion of DME in a rapid compression and expansion machine

Compression ignition of homogeneous charges in internal combustion (IC) engines is expected to offer high efficiency of DI diesel engines without high levels of NOx and particulate emissions. This study is int...

G. S. Jung, Y. H. Sung, B. C. Choi… in International Journal of Automotive Techno… (2009)

Article

Reaction characteristics of the diesel oxidation catalyst of particulate matters from the diffusion flame of a oiler burner

The objective of this experimental study is to investigate the characteristics of the size distribution and the number concentration of PM (particulate matters) emitted from the diffusion flame of a boiler bur...

H. N. Kim, T. J. Kim, B. C. Choi, M. T. Lim in International Journal of Automotive Techno… (2008)

Article

Improved cathodoluminescent characteristics of Y₂O₃:Eu³⁺ thin films by Li-do**

Y₂O₃:Eu³⁺ luminescent thin films have been studied as a potential red phosphor thin film for application in field emission display. Y₂O₃:Eu³⁺ and Li-doped Y₂O₃:Eu³⁺ films have been grown on Al₂O₃(0001) substrates...

S.S. Yi, K.S. Shim, H.K. Yang, B.K. Moon, B.C. Choi, J.H. Jeong… in Applied Physics A (2007)

Article

Ferroelectric phase transition of Nb-doped Bi_3.25La_0.75Ti₃O₁₂ ceramics

Bi_3.25La_0.75Ti_3-yNb_yO₁₂ (y=0.0, 0.03, 0.09, 0.15, 0.21) were synthesized using the solid-state reaction method. The effects of Nb do** on ferroelectric properties were studied through dielectric and P-E measure...

J.-H. Park, J.-S. Bae, B.-E. Jun, B.-C. Choi, J.-H. Jeong in Applied Physics A (2007)

Chapter

Time Domain Optical Imaging of Ferromagnetodynamics

Understanding the magnetic properties of small magnetic elements has become a major challenge in fundamental physics, involving both static and dynamic properties. The importance to technological applications ...

B.C. Choi, M.R. Freeman in Magnetic Microscopy of Nanostructures (2005)

Chapter

Nonequilibrium Spin Dynamics in Laterally Defined Magnetic Structures

B.C. Choi, M.R. Freeman in Ultrathin Magnetic Structures III (2005)

Article

Relationship between low frequency dielectric dispersion and ferroelectric phase transition in pulsed-laser-deposited Bi_4-xLa_xTi₃O₁₂ thin film

The frequency and temperature dependence of the complex dielectric constant of Bi_4-xLa_xTi₃O₁₂ (BLT, x=0.9) ferroelectric thin film was studied in the frequency range of 10^-1∼10⁶ Hz and the temperature range of 29...

J.H. Park, J.S. Bae, B.C. Choi, J.H. Jeong, H.J. Seo, B.K. Moon… in Applied Physics A (2004)

Article

Morphology-dependent luminescence behavior of Y_2-xGd_xO₃:Eu³⁺ thin-film phosphors grown by a laser ablation

Y_2-xGd_xO₃:Eu³⁺ luminescent thin films have been grown on Al₂O₃(0001) substrates using pulsed laser deposition. Films grown under different deposition conditions have been characterized using microstructural and l...

J.S. Bae, J.-C. Park, J.M. Park, H.J. Seo, B.C. Choi, J.H. Jeong… in Applied Physics A (2004)

Article

Impedance spectroscopy of KTiOPO₄ single crystal in the temperature range –100 to 100 °C

The electrical properties of a single crystal of KTiOPO₄ was studied by impedance spectroscopy methods in the temperature range –100 to 100 °C. The complex resistivity decreases rapidly with increasing temperatur...

J.-H. Park, C.-S. Kim, B.-C. Choi, B.K. Moon, H.-J. Seo in Applied Physics A (2004)