• Environmental Engineering Research
• /
• v.8 no.2
• /
• pp.91-97
• /
• 2003

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2001.05a
• /
• pp.156-158
• /
• 2001

• Archives of Plastic Surgery
• /
• v.32 no.4
• /
• pp.516-520
• /
• 2005

Multilayered cartilage graft has been clinically used at tip plasty, total ear reconstruction, and cleft lip nasal deformities. Perichondrial flap or a free perichondrium has been also commonly used for induction of neocartilage. However, the influence of perichondrium on multilayered cartilage graft to strength and growth rate is still unknown. The purpose of this study was to compare the strength and growth rate of different multilayered cartilage graft and to present the most ideal model of multilayered cartilage graft. Twenty New-zealand white rabbit were used. Triple layers of cartilage grafts with various perichondrium were inserted into six separate pockets in paravertebral region of rabbits. The grafts were grossly and microscopically observed on 8 and 16 weeks after grafting. On gross observation, the grafts showed marked enlargement of three layers of cartilage grafts with perichondrium compare with three layers of cartilage grafts without perichondrium In histologic examination, the number of PCNA-labelled cells were significantly high on three layers of cartilage grafts with perichondrium. In conclusion, this study suggested that triple-layer graft of cartilage grafts with perichondrium on the outside of triple-layer graft has strength and an effect on chondrogenetic induction by the perichondrium.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.2
• /
• pp.133-142
• /
• 2004

In this article, the constitutive relations of three types of piezoelectric benders, which are a unimorph bender, a bimorph bender and a triple-layer bender, are derived based on the beam theory under the quasi-static equilibrium condition. The relation coefficients are described as the geometry and material properties of the benders. More general constitutive relations involving fixed-free, fixed-roll, and fixed-simply supported boundary conditions under the inconsistent length condition between the piezoelectric layer and the nonpiezoelectric one are discussed. The complicated constitutive relations can be easily calculated and checked by using the symbolic function in ‘Mathematica’. The relation coefficients for the benders are plotted in three dimensional graph using the developed program.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.9 no.4
• /
• pp.403-413
• /
• 1985

Hot-wire measurements of second and third-order mean products of velocity fluctuations have been made in the separated, reattached, and redeveloping boundary layer behind a vertical fence. Mean velocity, wall static pressure distributions have also been measured in the whole flow field. Upstream of the reattachment point, the separated shear layer developes as a free mixing layer, but the gradient of the maximum slope thickness, turbulent intensities and the Reynolds shear stress are higher than that of the mixing layer due to initial streamline curvature and the effects of highly turbulent recirculating flow region. In the reattachment region, Reynolds shear stress and triple products near the surface is far more rapid than the decrease of the shear stress; that is the presence of the solid wall has a marked effect on the apparent gradient diffusivity of intensity or shear stress and throws doubts upon the usefulness of the simple gradient diffusivity model in this region.

• Journal of the Mineralogical Society of Korea
• /
• v.11 no.2
• /
• pp.106-116
• /
• 1998

The adsorption of Cs-137 and Sr-90 onto kaolinite in prescence of major groundwater cations (Ca2+, K+, Na+) with different concentrations was simulated by using triple-layer surface complexation model (TL-SCM). The site density (8.73 sites/nm2) of kaolinite used for TL-SCM was calculated from it's CEC and specific surface area. TL-SCM modeling results indicate that concentrations dependence on 137Cs and 90Sr adsorption onto kaolinite as a function of pH is best modeled as an outer-sphere surface reaction. This suggests that Cs+ and Sr2+ are adsorbed at the $\beta$-layer in kaolinite-water interface where the electrolytes, Nacl, KCl and CaCl2, bind. However, TL-SCM results on Sr adsorption show a discrepancy between batch data and fitting data in alkaline condition. This may be due to precipitation of SrCO3 and complexation such as SrOH+. Intrinsic reaction constants of ions obtained from model fit are as follows: Kintcs=10-2.10, KintSr=10-2.30, KintK=10-2.80, KintCa=10-3.10 and KintNa=10-3.32. The results are in the agreement with competition order among groundwater ions (K+>Ca2+>Na+) and sorption reference of nuclides (Cs-137>Sr-90) at kaolinite-water interface showed in batch test.

• Journal of the Korean Vacuum Society
• /
• v.6 no.S1
• /
• pp.43-46
• /
• 1997

High resolution x-ray diffraction and two dimensional triple axis mapping were used to characterize a group of GaN layers of about 1.1$\mu$m grown by direct current plasma molecular beam epitaxy technique on 6H-SiC(0001). A FWHM of 11.9 arcmins for an $\omega$ scan and 1.2 arcmins for an $\omega$/2$\theta$ scan were observed. A careful study of the rocking curves showed there were some large mosaics in the GaN layer and a tilt of $0.029^{\circ}$ between the GaN layer and the SIC substrate was detected. The two dimensional triple axis mapping showed that the GaN mosaica were disoriented in the (0001) plane but rather uniformed in direction perpendicular to the plane. A mosaics were disoriented in the (0001) plane but rather uniformed in direction perpendicular to the plane. A mosaic model was deduced to explain the phenomenon and the dislocation density was estimated to be about~$10^9\;\textrm{cm}^{-2}$ acc ding to the model.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.20 no.1
• /
• pp.377-383
• /
• 1996

Interaction of flames in a lean-rich concentration field is studied numerically adopting a counterflow as a model problem. Detailed kinetic mechanism is adopted in analyzing the structure of various type of flames which can be found in lean-rich interaction. Flow field is simplified to quasi one-dimensional by using boundary layer approximation and similarity formulation. Triple flames are identified and its structure shows that a diffusion flame is located in the middle of two premixed flames. Such a diffusion flame is formed by $H_2$ and CO generated from the rich premixed flame and $O_2$ leaked from the lean premixed flame. The flame position can be identified either from the hydrogen production rate or the heat release rate. Transition from single diffusion flame to triple flame is observed as degree of premixing is increased.

• 한국전산유체공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.142-147
• /
• 2005

A numerical study of evaluation of turbulence models for thermal striping phenomenon is performed. The turbulence models chosen in the present study are the two-layer model, the shear stress transport (SST) model and the V2-f model. These three models are applied to the analysis of the triple jet flow with the same velocity but different temperature. The unsteady Reynolds-averaged Navier-Stokes (URANS) equation method is used together with the SIMPLE algorithm. The results of the present study show that the temporal oscillation of temperature is predicted only by the V2-f model, and the accuracy of the mean velocity, the turbulent shear stress and the mean temperature is a little dependent on the turbulence model used. The the two-layer model and the SST model shows nearly the same capability of predicting the thermal striping and the amplitude of the temperature fluctuation is predicted best by the V2-f model.

• Journal of computational fluids engineering
• /
• v.10 no.4 s.31
• /
• pp.1-11
• /
• 2005

A numerical study of the evaluation of turbulence models for thermal striping phenomenon is performed. The turbulence models chosen in the present study are the two-layer model, the shear stress transport (SST) model and the V2-f model. These three models are applied to the analysis of the triple-jet flow with the same velocity but different temperatures. The unsteady Reynolds-averaged Navier-Stokes (URANS) equation method is used together with the SIMPLEC algorithm. The results of the present study show that the temporal oscillation of temperature is predicted by the SST and V2-f models, and the accuracy of the mean velocity, the turbulent shear stress and the mean temperature is a little dependent on the turbulence model used. In addition, it is shown that both the two-layer and SST models have nearly the same capability predicting the thermal striping, and the amplitude of the temperature fluctuation is predicted best by the V2-f model.