• Journal of the Korean Chemical Society
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• v.57 no.3
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• pp.329-334
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• 2013

A pine needle-embedded graphite enzyme electrode, of which bonding agent is CSM rubber, was newly designed and its electrochemistry was studied based on the amperometry. It involved a ground green leaves of pine tree as a zymogen together with electrochemical mediator, ferrocene within the paste. The plots of ln($i(1-e^{nf{\eta}})$) vs. ${\eta}$ and Lineweaver-Burk at the low potential (-100 to -500 mV) showed good linearities indicating that the amperometric response is by the catalytic power of pine peroxidase. Electrochemical parameters obtained, symmetry factor (${\alpha}$, 0.17), limiting current ($i_1$, 1.99 $A/cm^2$), exchange current density ($i_0$, $5.86{\times}10^{-5}\;A/cm^2$), Michaelis constant ($K_M$, $1.68{\times}10^{-3}$ M) and many others showed that pine peroxidase discharges the role of catalyst quantitatively on the electrode surface. Those proved that the practical use of pine peroxidase is promising in place of the marketed.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2931-2936
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• 2013

This paper presents results for the calculation of transport properties of noble gases (He, Ne, Ar, Kr, and Xe) at 273.15 K and 1.00 atm using equilibrium molecular dynamics (EMD) simulations through a Lennard-Jones (LJ) intermolecular potential. We have utilized the revised Green-Kubo formulas for the stress (SAC) and the heat-flux auto-correlation (HFAC) functions to estimate the viscosities (${\eta}$) and thermal conductivities (${\lambda}$) of noble gases. The original Green-Kubo formula was employed for diffusion coefficients (D). The results for transport properties (D, ${\eta}$, and ${\lambda}$) of noble gases at 273.15 and 1.00 atm obtained from our EMD simulations are in a good agreement with the rigorous results of the kinetic theory and the experimental data. The radial distribution functions, mean square displacements, and velocity auto-correlation functions of noble gases are remarkably different from those of liquid argon at 94.4 K and 1.374 $g/cm^3$.

• Bulletin of the Korean Mathematical Society
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• v.56 no.5
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• pp.1315-1325
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• 2019

The purpose of this article is to study the Ricci solitons and Ricci almost solitons on para-Kenmotsu manifold. First, we prove that if a para-Kenmotsu metric represents a Ricci soliton with the soliton vector field V is contact, then it is Einstein and the soliton is shrinking. Next, we prove that if a ${\eta}$-Einstein para-Kenmotsu metric represents a Ricci soliton, then it is Einstein with constant scalar curvature and the soliton is shrinking. Further, we prove that if a para-Kenmotsu metric represents a gradient Ricci almost soliton, then it is ${\eta}$-Einstein. This result is also hold for Ricci almost soliton if the potential vector field V is pointwise collinear with the Reeb vector field ${\xi}$.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.34-43
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• 1996

Determining the actual evapotranspiration(ETa) of a crop, and appropriate water management of the crop based on the ETa are very important For increasing the yield. The present study aimed at determining ETa and crop coefficient of sesame growing under different climatic conditions with the transparent thin polyethylene film mulch(0.03 mm thick) and without this mulch. Bottomless cylindrical lysimeters(105cm in diameter, 120cm in height, protruded 20 cm above the soil surface) were installed on the field of sandy loam "Bonyang series" soil with a moderate drainage. The determination of ETa was performed by measuring each component of a model equation, $ETa=(R+I)-\{Ro+(D1+D2)\}+C{\pm}{\Delta}S$. Sesame, cv. "Ansan" was sown in two rows with the spacing of $50{\times}15cm$ on May 10 in 1991 and 1992. The mulching covers 80% of the soil surface. Sesame consumed the water of 139.0 mm(1.53 mm/day) and 171.2 mm(1.59 mm/day) in ETa without the film mulch, but that of 132.6 mm(1.46 mm/day) and 199.8 mm(1.85 mm/day) with its mulching through both years of 1991 and 1992, respectively. The ETa's accounted for 52 and 69% of the potential evapotranspiration(ETp) in the mulched crop, and 54 and 59% of ETp in the non-mulched crop 1991 through 1992, respectively. Its ETa's were much more and their gap between the mulching and non-mulching treatment was larger in 1992 than in 1991 as a result of the better climatic condition of 1992.

• Bulletin of the Korean Chemical Society
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• v.3 no.3
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• pp.83-88
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• 1982

Viscosity and zeta-potential of 11.0 wt. % aqueous bentonite suspension containing various electrolytes and hydrogen-ion concentration were measured by using a Couette type automatic rotational viscometer and Zeta Meter, respectively. The effects of pH and elcctrolytes on the rheological properties of the suspension were investigated. A system, which has a large zeta-potcntial, has a small intrinsic relaxation time ${\beta}$ and a small intrinsic shear modulus $1/{\alpha}$ in the Ree-Eyring generalized viscosity equation, i.e., such a system has a small viscosity value, since ${\eta}={\beta}/{\alpha}$. In general, a stable suspension system has large zeta-potential. The stability condition of clay-water suspension can be estimated by viscometric method since stable suspension generally has small viscosity. The correlation between the stability, viscosity and zeta-potential has been explained by the Ree-Eyring theory of viscous flow.

• Communications of the Korean Mathematical Society
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• v.38 no.1
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• pp.235-242
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• 2023

In this paper, we studied several geometrical aspects of a perfect fluid spacetime admitting a Ricci ρ-soliton and an η-Ricci ρ-soliton. Beside this, we consider the velocity vector of the perfect fluid space time as a gradient vector and obtain some Poisson equations satisfied by the potential function of the gradient solitons.

• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.87-98
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• 2013

This study was performed a series of the isotropic compression-expansion tests and the drained triaxial tests with various the relative densities 40%, 60%, 80% and 95% for bottom ash. Using the tests results the characteristic of the parameters of Lade's single hardening constitutive model were investigated. The soil parameters Kur and n representing elastic behavior are not much affected by the change of the relative density. The other parameters such as failure criterion(m, ${\eta}_1$), hardening function(c, p) and plastic potential(${\psi}_2$, ${\mu}$) are in a positive linear relationship with the relative density. Since the soil parameters h and ${\alpha}$ representing yield function do not change much to the change of relative density and also closely related to failure criterion, they can be replaced by failure criterion ${\eta}_1$. We also observed that predicted values from the Lade's single hardening constitutive model were well consistent with the observed data.

• Journal of the Korean institute of surface engineering
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• v.18 no.4
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• pp.153-163
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• 1985

In the electroless nickel plating bath which contained nickel sulfate, sodium hypophosphite, boric acid and triethanolamine, effect of their concentration on the rate of deposition was tested by gravimetric method and polarization method. The polarization method that polarize small range of voltage anodicaly and cathodicaly at the mixed potential in the electroless plating bath can calculate mixed current (depositing rate) from $i_{mp}=\frac {i}{\eta}\;\frac{RT}{nF}\;or\;i_{mp}=\frac{i}{\eta}\;\frac{1}{2.3}(\frac{b_a\;\;b_c}{b_c+b_a})$ Where $i_{mp}$ is the depositing current, i is the polarized current, ${\eta}$ is the polarized voltage, $b_a\;and\;b_c$ are the Tafel slop of anodic and cathodic polarization curves respectively. The calculated mixed current ($i_{mp}$) is proportional to the depositing rate obtained by gravimetric method and corresponded mostly to the real depositing rate by multifying supplementary constant. The polarization method can be used for founding inclination of reaction on various concentration of each composition. Decreasing or increasing concentration of triethanolaminc as a complexing agent , the depositing rate is decreased and when the bath contained 25-50mL/L of triethanoloamine, the depositing rate is increased. The depositing rate is increased with increasing the concentration of boric acid, and when the bath contained 0.5M of boric acid, the depositing rate is increased abruptly. The optimum composition of the electroless nickel bath was estimated 0.1M of nickel sulfate, 0.25M of sodium hypophosphite, 0.5M of boric acid, and 25-50mL/L of triethanalamine.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1C
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• pp.11-17
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• 2011

This study was performed a series of the isotropic compression-expansion tests and the drained triaxial tests with various the relative densities 25%, 50%, 80% and 100% for Baekma river sand. Using the tests results the characteristic of the parameters of Lade's single hardening constitutive model were investigated. The soil parameters Kur and n representing elastic behavior are not much affected by the change of the relative density. The other parameters such as failure criterion (m, ${\eta}_1$), hardening function (C, p) and plastic potential (${\Psi}_2$, ${\mu}$) are in a positive linear relationship with the relative density. Since the soil parameters h and $\alpha$ representing yield function do not change much to the change of relative density and also closely related to failure criterion, they can be replaced by failure criterion ${\eta}_1$. We also observed that predicted values from the Lade's single hardening constitutive model were well consistent with the observed data.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.5
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• pp.278-282
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• 2018

We propose a SPICE model of drain-induced barrier lowering (DIBL) for a junctionless cylindrical surrounding gate (JLCSG) MOSFETs. To this end, the potential distribution in the channel is obtained via the Poisson equation, and the threshold voltage model is presented for the JLCSG MOSFET. In a JLCSG nano-structured MOSFET, a channel radius affects the carrier transfer as well as the channel length and oxide thickness; therefore, DIBL should be expressed as a function of channel length, channel radius, and oxide thickness. Consequently, it can be seen that DIBLs are proportional to the power of -3 for the channel length, 2 for the channel radius, 1 for the thickness of the oxide film, and the constant of proportionality is 18.5 when the SPICE parameter, the static feedback coefficient ${\eta}$, is between 0.2 and 1.0. In particular, as the channel radius and the oxide film thickness increase, the value of ${\eta}$ remains nearly constant.