• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1107-1112
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• 1999

We investigated the inhibitory effects of phytol and methyl 11,14,17 eicosatrienoic acid (methyl ETA, n 3, 20 : 3) separated from perilla leaves on the growth of human cancer cells. Phytol inhibited significantly the growth of HT 29 human colon cancer cells, MG 63 osteosarcoma cells and AZ 521 gastric cancer cells. Although the activity of methyl ETA was lower than that of phytol, it was also observed to have the inhibitory effect on three human cancer cell lines. Furthermore, the DNA synthesis of the MG 63 osteosarcoma cells was markedly decreased by the addition of the phytol and methyl ETA. These results suggest that phytol and methyl ETA identified from the perilla leaves may play a role on the growth inhibition of the human cancer cells.

• Journal of the Korean institute of surface engineering
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• v.24 no.1
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• pp.16-16
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• 1991

Generally brittle eta phase produced during TiC deposition has a effect on the TRS (transverse rupture strength ; thoughness). Therefore it is necessary to reduce eta(η), phase for the improvement of tool life. At this experiment some properties (TRS, bonding strength, tool life, eta phase)have been investigated by inserting TiN or TiCN underlayer between TiC layer and substrate. The results obtained were as follows; 1. by inserting underlayer eta phase were decreased and TRS was increased, but the bonding strength was decreased. 2. the diffusion of W, Co from the substrate was hindered by the underlayer. 3. TiC layer with TiCN underlayer had the finsest grain size. 4. by inserting underlayer (TiCN or TiN) the tool life was improved and especially notch and crater wear resistance was greatly improved.

• Journal of the Korean institute of surface engineering
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• v.25 no.1
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• pp.16-23
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• 1992

Generally brittle eta phase produced during TiC deposition has a bad effect on the TRS (transverse rupture strength ; thoughness). Therefore it is necessary to reduce eta(η) phase for the improvement of tool life. At this experiment some properties (TRS, bonding strength, tool life, eta phase) have been investigated by inserting TiN or TiCN underlayer between TiC layer and substrate. The results obtained were as fellows; 1. by inserting underlayer eta phase was decreased and TRS was increased, but the bonding strength was decreased. 2. the diffusion of W, Co from the substrate was hindered by the underlayer. 3. TiC layer with TiCN underlayer had the finsest gain size. 4. by inserting underlayer (TiCN or TiN) the tool life was improved and especially notch and crater wear resistance was greatly improved.

• Communications of the Korean Mathematical Society
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• v.23 no.1
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• pp.95-110
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• 2008

The object of the present paper is to provide the existence of LP-Sasakian manifolds with $\eta$-recurrent, $\eta$-parallel, $\phi$-recurrent, $\phi$-parallel Ricci tensor with several non-trivial examples. Also generalized Ricci recurrent LP-Sasakian manifolds are studied with the existence of various examples.

• Bulletin of the Korean Chemical Society
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• v.17 no.2
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• pp.138-142
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• 1996

The transition metal carbonylate, PPN+(${\eta}^5-MeCp)Mn(CO)_2Cl^-$ undergoes a novel ligand substitution reaction with PR3 (R=Me, Et, OEt, $C_6H_5$ in THF at elevated temperatures (40 $^{\circ}C$ up to 60 $^{\circ}C)$ under the pseudo-first-order reaction conditions (usually 20-fold excess of PR3 with respect to metal carbonylate concentrations) where chloride is displaced by PR3. The reaction follows overall first order dependence on [(${\eta}^5-MeCp)Mn(CO)_2Cl^-$]; however, the negative entropy changes of activation (${\Delta}S^{\neq}$=-19.3 e.u. for $P(OEt)_3$; ${\Delta}S^{\neq}$=-16.4 e.u. for $PPh_3$) suggest the existence of the intermediate, ((η3-MeCp)Mn(CO)2(THF)Cl-, which eventually transforms to the product (${\eta}^5-MeCp)Mn(CO)_2(PR_3)$.

• Bulletin of the Korean Chemical Society
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• v.11 no.2
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• pp.134-139
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• 1990

The hydrogenation catalyst precursors $[(L-L)Rh(NBD)]ClO_4\;(L-L=Fe({\eta}^5-C_5H_4PBu^t\;_2)_2,\;Fe({\eta}^5-C_5H_4PPhBu^t)_2$; NBD = norbornadiene) react with $H_2(1\;atm,\;30^{\circ}C$, MeOH) to yield $[(L-L)HRh({\mu}-H)_3RhH(L-L)]ClO_4$. These hydrido species are fluxional, and variable temperature NMR studies show the existence of a number of equilibria involving both fluxional and non-fluxional species. The synthesis, solution structures, and fluxional behaviors of these hydrides are described.

• Bulletin of the Korean Mathematical Society
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• v.32 no.1
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• pp.103-113
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• 1995

Let $S^{n+p}$(c) be the (n + p)-dimensional Euclidean sphere of constant curva ture c and let M be an n-dimensional compact minimal submanifold isometric ally immersed in $S^{n+p}$(c). Let $A_\xi$ be the second fundamental form of M in the direction of a normal $\xi$ and T the tensor defined by $T(\xi, \eta) = traceA_\xi A_\eta$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.92-96
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• 1996

To elucidate the flow properties of carboxymethyl chitin (CM-chitin), the critical concentration and flow equation of aqueous CM-chitin solution were investigated. The concentration of $0.8\%$ appeared to be the critical concentration. So interaction occurred between polymer chains in the CM-chitin solutions had the higher concentration than $0.8\%$ but not in lower than $0.8\%.\;0.5\%$ CM-chitin solution was revealed as a newtonian flow but $1.0\%$ CM-chitin solution showed a pseudoplastic flow. Flow constants of $3.0\%$ CH-chitin solution were 0.0908cp for $\eta_\infty$, 770cp for $\eta_0$, 0.81 for $\beta$ and 0.36 for n. Therefore, flow equation of $3.0\%$ CM-chitin solution was as follow; $$\eta=0.1+\{{770/(1+0.81D^{0.36})\}$$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.48-54
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• 2004

The effects of injector spacing s and injector diameter d on mixing are numerically investigated in supersonic combustor with perpendicular injection behind a backward-facing step. Simulations are reported for airstream Mach number of 2.4. Parameters are changed on following 4 cases to investigate the effects of injector configuration on mixing efficiency $\eta_m$. In the case of varying d or s, dynamic pressure ratio $Rq(=(pu^2)_j/(pu^2)_a)$ is also varied to keep bulk equivalence ratio $\Phi({\oe})Rq.d^2/s)$ constant. (l) Injector spacing s is varied at constant $\Phi$=0.5, 1, 2 for injector diameter d=6mm. In the case of $\Phi$=1, $\eta_m$ has its maximum value at s=24mm. The reason is that increase of $\eta_m$. , by widening spacing at Rq=constant competes with decrease of $\eta_m$ by increasing Rq at s=constant. When spacing is narrow, the flow field of vicinity of injector becomes two-dimensional because adjacent jets interferes each other. By widening spacing, air is easily entrained by three-dimensional effect. This mechanism also appears in the case of $\Phi$=0.5, 2 for d=6mm, and $\eta_m$. reaches its maximum value at s=24mm for $\Phi$=0.5 and at s=42mm for $\Phi$=2. (2) In the case of injector diameter d varied at $\Phi$=1 for s=30mm, $\eta_m$. has its maximum value at d=3mm. The reason is that decrease of $\eta_m$ by increasing injector diameter competes with increase of $\eta_m$ by decreasing Rq at d=constant.(3) In the case of s varied at $\Phi$=0.5, 1,2 for d=3mm, the injector spacing at which mixing efficiency has its maximum value is s= 18mm for $\Phi$=0.5, s=24mm for $\Phi$=1, s=24mm for $\Phi$=2. Therefore it is found that d=3mm and s=24mm can be optimum configuration over a range of $\Phi$=0.5~2.(4) The effect of h on the optimum spacing is investigated. s is varied for d=6mm at step height h=4, 6, 8mm. The simulation results do not show significant change on the step height.

• Preventive Nutrition and Food Science
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• v.19 no.3
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• pp.242-245
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• 2014

The flow behaviors of three thickened fruit juices (orange, apple, and grape juice) prepared with a commercial instant xanthan gum (XG)-based thickener that is marketed in Korea were investigated at different thickener concentrations (1.0%, 1.5%, 2.0%, 2.5%, 3.0%, and 3.5%) and setting times (5 and 30 min) using a rheometer and a line-spread measurement method. The flow distance values measured by the line-spread test (LST) were compared with the apparent viscosity (${\eta}_{a,50}$) values measured with a sophisticated computer-controlled rheometer. The ${\eta}_{a,50}$ values of the juices increased as thickener concentration increased, whereas their flow distances decreased. The ${\eta}_{a,50}$ values at the 30-min setting time were much higher than those at the 5-min setting time, indicating that the setting time before serving or consuming thickened juices can affect viscosity values. Plots comparing ${\eta}_{a,50}$ values to LST flow distances revealed strong exponential relationships between the two measures ($R^2$=0.989 and $R^2$=0.987 for the 5- and 30-min setting times, respectively). These results indicate that the LST can be a suitable instrument for evaluating the viscosity of thickened fruit juices prepared with different XG-based thickener concentrations and setting times for the dysphagia diet.