• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.33-40
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• 1988

In this study, effects of the density of soil and the confining pressure applied to the soil sample on the elastic moduli of subgrade soils are experimentally analyzed. Through investigation of subgrade materials of domestic expressways, five typical types of subgrade soils are selected for the experiments. A series of unconsolidated undrained triaxial tests is performed on samples prepared with various water contents and densities at the confining pressures of 1.02, 2.04, and $3.06kg/cm^2$. Initial tangent modulus is inferred from the unloading-reloading portion of the stress strain curve obtained during an individual loading-unloading-reloading test. As a result of the analysis, it is found that the effect of the confining pressure on the elastic modulus of subgrade material is well consistent with the equation proposed by Janbu, and that the elastic modulus can be related to the dry unit weight expressing the Janbu constants as exponentiial functions of it. It is also found that the water content has little effect on the elastic modulus for the samples with the degree of saturation less than 70%.

• Biomolecules & Therapeutics
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• v.25 no.6
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• pp.648-658
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• 2017

7-O-Succinyl macrolactin A (SMA) exerts several pharmacological effects including anti-bacterial, anti-inflammation, and anti-cancer activities. Recently, SMA has been extensively evaluated as an anti-cancer drug. Thus, the objectives of the present study were to characterise the pharmacokinetics of SMA via both non-compartmental and compartmental analysis in mice, rats, and dogs, and to derive an appropriate first-in-man dose based on allometric scaling of the animal data. The time courses of plasma SMA concentrations after intravenous administration to rats and dogs were analysed retrospectively, as were data collected after intraperitoneal SMA injection in mice. Pharmacokinetic parameters were estimated via both noncompartmental and compartmental analysis, and were correlated with body weight and/or the potential maximum life-span. The clearance and distribution volume of SMA in humans were predicted, and a first-in-man dose proposed. A two-compartment model best described the time courses of SMA plasma concentrations after a saturation elimination process was applied to fit the dataset obtained from rats. Incorporation of the maximum potential life-span during allometric scaling was required to improve the estimation of human clearance. The SMA clearance and the distribution volume in the steady state, in a 70-kg adult male, were estimated to be 30.6 L/h and 19.5 L, respectively. To meet the area under the curve (AUC) required for anti-tumour activity, a dose of 100 mg (~1.5 mg/kg) was finally proposed as the first dose for a 70-kg human. Although toxicological profiles derived from non-clinical studies must be considered before any final decision is made, our work will facilitate clinical studies on SMA.

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.1-11
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• 2009

Although the exterior wood such as column may frequently contact with liquid water, little work has been found to measure liquid water absorption in wood. To investigate the moisture diffusivity of wood in the longitudinal direction including bound water and free water movement, liquid water absorption test was conducted at the room temperature. The order of magnitude for absorption coefficient and diffusivity was Japanese elm, horn beam, hemlock, spruce, radiata pine, and painted maple. The Boltzmann transformation method was used to determine the diffusivity from measured moisture content distributions in the absorption test. The shape of the curve representing the dependence of diffusivity with moisture content was similar in test samples. The diffusivity decreased with increasing moisture content until around the fiber saturation point and then increased at the nonhygroscopic region, which ranged from $10^{-10}$ to $10^{-7}m^2/s$.

• Current Photovoltaic Research
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• v.2 no.3
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• pp.135-139
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• 2014

Different power output of solar cells can be observed at high-temperature regions such as desert areas. In this study, performance dependence on operating temperature of crystalline silicon solar cells with different emitter types was analyzed. Based on the light current-voltage (LIV) measurement, temperature coefficients of short-circuit current density ($J_{SC}$), open-circuit voltage ($V_{OC}$), fill factor (FF) and power conversion efficiency were measured and compared for two groups of crystalline silicon solar cells with different emitter types. One group had homogeneously doped (conventional) emitter and another selectively doped (selective) emitter. Varying the operating temperature from 25 to 40, 60, and $80^{\circ}C$, LIV characteristics of the cells were measured and the properties of saturation current densities ($J_0$) were extracted from dark current-voltage (DIV) curve. From the DIV data, effect of temperature on the performance of the solar cells with different electrical structures for the emitter was analyzed. Increasing the temperature, both emitter structures showed a slight increase in $J_{SC}$ and a rapid degradation of $V_{OC}$. FF and power conversion efficiency also decreased with the increasing temperature. The degrees of $J_{SC}$ increase and $V_{OC}$ degradation for two groups were compared and explained. Also, FF change was explained by series and shunt resistances from the LIV data. It was concluded that the degradation of solar cells shows different values at different temperatures depending on the emitter type of solar cells.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.443-451
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• 1994

The binding characteristics of pirenzepine and oxomemazine to muscarinic receptor were studied to evaluate the selectivity of oxomemazine for the muscarinic receptor subtypes in rat cerebral microsomes. Equililbrium dissociation constant $(K_D){\;}of{\;}(-)[^3H]$quinuclidinyl benzilate$([^3H)QNB)$ determined from saturation isotherms was 64-pM. Analysis of the pirenzepine inghibition curve of [$^3H$]QNB binding to cerebral microsome indicatd the presence of two receptor subtypes with high $(K_1 = 16 nM, M_1 receptor)$two receptor subypes with about 20-fold difference in the affinity for high $(k_1 = 84nM, {\;} O_H receptor){\;} and {\;}low{\;} (K_1{\;} ={\;} 1.65\muM, {\;} O_L receptor$) affinity sites. The percentage populations of $M_1{\;} and M_3$, /TEX> receptors to the total receptors were 61 : 39, and those of $O_H{\;} and{\;} O_L$ receptors 39 : 61, resepectively. Both pirenzepine and oxomemazine increaed the $K_D$ value for $[^3H]QNB$ without affecting the binding site concentrations and Hii coefficient for the $[^3H]QNB$ without affecting the binding site concentractions and Hill coefficient for the [$^{3}$H]QNB binding. Oxomemazine had a 10-fold higher affinity at $M_1$ receptors than at $M_3$ receptors, and pirenzepine a 8-fold higher affinity at $O_H$ receptors were of $O_H$ receptors and 71% of $M_3$ receptors. However, $M_3$for oxomemazine and $O_H$for pirenzepine were composed of a uniform population. These results suggest that oxomemazine could be classified as a selective drug for $M_1$ receptors and also demonstrate that rat cerebral microsomes contain three different subtypes of $M_1{\;} M_3$ and the other site which is different from $M_1, {\;} M_2$, /TEX> receptors.

• Clean Technology
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• v.20 no.2
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• pp.166-170
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• 2014

The continuous experiments were carried out using fixed-bed column packed with strong-acid cation exchange resin for the removal of lithium ions from aqueous solution. The parameters such as bed height, flow rate and inlet concentration were investigated. Breakthrough time ($t_{0.05}$), saturation time ($t_{0.95}$), and total amount of lithium ion removed (mtotal) were obtained from the breakthrough curves. The results showed that $t_{0.05}$ and $t_{0.95}$ decreased with decreasing bed height, and decreased with increasing inlet concentration and flow rate. mtotal increased with increasing inlet concentration and bed height, but decreased with increasing flow rate. Thomas model and Yoon-Nelson model equations were applied to the experimental data, the results showed that the breakthrough data gave a good fit to Thomas model equation.

• Journal of the Korean Magnetics Society
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• v.4 no.1
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• pp.25-31
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• 1994

The magnetic properties of aluminum anodized film in which Co-Fe alloy electrodeposited are investigated with regard to the alloy composition of magnetic films. The electrodeposited Co-Fe particles are confirmed to be single phase Co-Fe alloys by X-ray diffractions. At 34 at% Co, the sample with small pore diameter(particle diameter $150\;{\AA}$) has a large magnetic energy product($B_{max}$) of about 1.44 MGOe due to the large saturation magnetization, the high coercive force and good squareness of the M-H curve. However, for the samples with particle diameter larger than $450\;{\AA}$, the bottom of each particle forms abnormal particle claaed branch-shaped unlike the sample of the particle diameter $150\;{\AA}$. In this case, the magnetic anisotropy energy was about zero at the compositions of 45 and 75 at% Co. Moreover, at the compositions from 50 to 70 at% Co, the anisotropy became negative value. This means that an easy axis of magnetization of the film is in plane in plane in spite of the perpendicular shape anisotropy of the particle. It was found that the bottom extremity of the particle contains FeC from the X-ray diffraction. Thus the effect of the bottom extremity, that is, an unusal magnetic property was removed by electrodepositing Cu at the bottom extremity of the particle. Itis clear that the magnetic properties of the ilms are influenced by he branch-shaped bottom extremity filled with FeC.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.827-833
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• 2018

Plasma lighting systems have been engineered to simulate sunlight. The objective of this study was to determine the effects of plasma lighting on tomato plant growth, photosynthetic characteristics, flowering rate, and physiological disorders. Tomato plants were grown in growth chambers at air temperatures of $25/23^{\circ}C$ (light/dark period), in a $16h\;day^{-1}$ light period provided by four different light sources: 1 kW and 700 W sulfur plasma lights (1 SPL and 0.7 SPL), 1 kW indium bromide plasma light, and 700 W high pressure sodium lamp (0.7 HPS) as a control. The totaldry weight and leaf area at 0.7 SPL were approximately 1.2 and 1.3 times greater, respectively, than that of 0.7 HPS at the 62 days after sowing (DAS). The maximum light assimilation rate was observed at 1 SPL at the 73 DAS. In addition, the light compensation and saturation points of the plants treated with plasma lighting were 98.5% higher compared with HPS. Those differences appeared to be related to more efficient light interception, provided by the SPL spectrum. The percentage of flowering at 0.7 SPL was 30.5%, which was higher than that at 0.7 HPS; however, there were some instances of severe blossom end rot. Results indicate that plasma lighting promotes tomato growth, flowering, and photosynthesis. Therefore, a plasma lighting system may be a valuable supplemental light source in a greenhouse or plant factory.

• Radiation Oncology Journal
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• v.6 no.1
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• pp.1-11
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• 1988

Recovery from potentially lethal damage (PLDR) after irradiation was studied in plateau-phase culture of Vero cells in vitro. Unfed plateau-phase cells were irradiated with dose of 1 to 9Gy using Cs-137 irradiator. Cells then were incubated again and left in situ for 0, 1, 2, 3, 4, 5, 6, and 24 hours and then were trypsinized explanted, and subcultured in fresh RPMI-1640 media containing $0.33\%$ agar. Cell survival was measured by colony forming ability. An adequate number of heavily irradiated Vero cells were added as feeder cells to make the total cell number constant in every culture dish. As the postirradiation in situ incubation time increased, surviving fraction increased by PLDR. The rate of PLDR was so rapid that increased surviving fraction reached saturation level at 2 to 4 hours after in situ incubation. As the radiation dose increased, the rate of PLDR fastened and the magnitude of increased surviving fraction at saturation level by PLOR also increased. In analysis of cell survival curve fitted to the linear-quadratic model, the linear inactivation coefficient $(\alpha)$ decreased largely and reached nearly to zero but the quadratic inactivation coefficient $(\beta)$ increased minimally by increment of postirradiation in situ incubation time. So PLDR mainly affected the damage expressed as $\alpha$, In the multitarget model, significant change was not obtained in $D_0\;but\;in D_q$. Therefore, shoulder region in cell survival curve was mainly affected by PLDR and terminal slope was not influenced at all. And dose-modifying factor by PLDR was relatively higher in shoulder region, that is, in low dose area below 3 Gy.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.401-409
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• 2021

This study aimed to estimate the photosynthetic capacity of tomato plants grown in a semi-closed greenhouse using temperature response models of plant photosynthesis by calculating the ribulose 1,5-bisphosphate carboxylase/oxygenase maximum carboxylation rate (V_cmax), maximum electron transport rate (J_max), thermal breakdown (high-temperature inhibition), and leaf respiration to predict the optimal conditions of the CO₂-controlled greenhouse, for maximizing the photosynthetic rate. Gas exchange measurements for the A-C_i curve response to CO₂ level with different light intensities {PAR (Photosynthetically Active Radiation) 200µmol·m^-2·s^-1 to 1500µmol·m^-2·s^-1} and leaf temperatures (20℃ to 35℃) were conducted with a portable infrared gas analyzer system. Arrhenius function, net CO₂ assimilation (A_n), thermal breakdown, and daylight leaf respiration (R_d) were also calculated using the modeling equation. Estimated J_max, A_n, Arrhenius function value, and thermal breakdown decreased in response to increased leaf temperature (> 30℃), and the optimum leaf temperature for the estimated J_max was 30℃. The CO₂ saturation point of the fifth leaf from the apical region was reached at 600ppm for 200 and 400µmol·m^-2·s^-1 of PAR, at 800ppm for 600 and 800µmol·m^-2·s^-1 of PAR, at 1000ppm for 1000µmol of PAR, and at 1500ppm for 1200 and 1500µmol·m^-2·s^-1 of PAR levels. The results suggest that the optimal conditions of CO₂ concentration can be determined, using the photosynthetic model equation, to improve the photosynthetic rates of fruit vegetables grown in greenhouses.