• Korean Journal of Medicinal Crop Science
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• v.26 no.3
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• pp.205-213
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• 2018

Background: Since the revised Ginseng Industrial Act was passed, ginseng sprouts have become a new medicinal vegetable for which there is high consumer demand. However, the existing amount of research and data on ginseng production has not kept pace with this changed reality. Methods and Results: In this study we analyzed the changes in the amounts of ginsenosides in different parts of growing ginseng sprouts during the period from when organic seedlings were planted in nursery soil until 8 weeks of cultivation had elapsed, which was when the leaves hardened. In the leaves, ginsenoside content increased 1.62 times with the panaxadiol (PD) system and 1.31 - 1.56 times with the panaxatriol (PT) system from 7 to 56 days after transplantation. During the same period, the total ginsenoside content of the stems decreased by 0.66 - 0.91 times, and those of the roots increased until the $21^{st}$ day, and then underwent steep declines. The effect of fermented press cake extract (FPCE) and tap water (TP) on the total amount of ginsenoside per plant were similar, and could be represented with the equations $y=1.4330+0.2262x-0.0008x^2$ and $y=0.9555+0.2997x-0.0031x^2$ in which y = ginsenoside content x = amount of and on the total amounts of FPCE or TP, respectively after 26.4 days, however, the difference between ginsenoside content with FPCE and TP widened. Conclusions: These results suggested that the amounts of ginsenosides in different parts of ginseng varied with the cultivation period and nutrient supply. These findings also provide fundamental data on the distribution of ginsenosides among plant parts for 2-year-old ginseng plants in the early-growth stage.

• Korean Journal of Environmental Biology
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• v.24 no.1 s.61
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• pp.60-66
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• 2006

This study was carried out to obtain the biological fundamental data for the resources annexation of Crassostrea ariakensis in terms of the effect of temperature and salinity on growth. Water temperature during the sampling period was $3.5\sim26.2^{\circ}C$ and there was a little difference between each sites. Salinity was ranged from 2.6 to 29.5 psu, its maximum in Baealdo and its minimum in Dontak. The fatness index was the higher in Dontak than the other sites. In August, the value was the lowest in 3 sites. Therefore Crassostrea ariakensis is likely to have spawning period June and July. Size values $(mean{\pm}S.D.)$ of shell height was $149.7{\pm}19.8\;mm$ (Baealdo), $148.6{\pm}21.3\;mm$ (Seomjin bridge) and $143.1{\pm}17.6\;mm$ (Dontak), respectively. Relative growth equations among SH, SL, SW, TW and MW of Crassostrea ariakensis were ranged from 0.024 to 0.0471.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1175-1179
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• 1999

The rheological properties of highly filled epoxy molding compound(EMC) for semi-conductor encapsulants are greatly affected by the content of filler loaded. In this study, the change of viscosity of EMC for semi-conductor encapsulants with the filler content was investigated. Also, both of Cox-Merz and modified Cox-Merz equations were applied to convert the viscosity change as a function of frequency to that of shear rate. It was ovserved that shear thinning and yield stress occured at high filler contents and that the Cox-Merz equation could not be applied at high filler contents because of the difference of viscosity according to the various strains. When the modified Cox-Merz equation was applied, the all the curves having different strain tend to be represented by one master curve, even though some deviation was obseved at high filler content and strain.

• Journal of the korean Society of Automotive Engineers
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• v.2 no.1
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• pp.21-31
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• 1980

Two phase boundary layer equations of laminar filmwise condensation are solved by an approximate integral method under the following condition; saturated vapour flows vertically downward over a cooled surface of uniform temperature, the condensate film is so thin that the inertia and convection terms are neglected. The following conclusions are drawn under the above assumptions. 1. free convection In case of the linear temperature profile in a liquid film, numerical results for the average coefficients of heat transfer may be expressed as N $u_{m}$=4/3,(G $r_{l}$ /4.H)$^{1}$4/ and in case of the quadratic profile, numerical results may be expressed as N $u_{m}$=2/1.682,(G $r_{l}$ /H)$^{1}$4/. 2. Forced convection When the temperature profile is assumed to be linear in a liquid film, numerical results fir the average heat transfer coefficients may be expressed as N $u_{m}$=(A, R $e_{l}$ /H)$^{1}$2/. This expression is compared with the experimental results hitherto reported; For theoretical Nusselt number (N $u_{m}$)$_{th}$<2*10$^{4}$, the experimental Nusselt number (N $u_{m}$)$_{exp}$ is on the average larger than theoretical Nusselt number (N $u_{m}$)$_{th}$ by 30%. For (N $u_{m}$)$_{th}$>2*10$^{4}$, experimental Nusselt number (N $u_{m}$)$_{exp}$ is about 1.6 times as large as theoretical Nusselt number (N $u_{m}$)$_{th}$. These large deviation may be caused by the presence of turbulence in the liquid film. In case of the quadratic temperature profile in a liquid film, numerical results for the average coefficients of heat transfer may be expressed as N $u_{m}$'=(2,A,Re/H)$^{1}$2/. This formular shows that theoretical Nusselt number (N $u_{m}$)$_{th}$ is larger than experimental Nusselt number (N $u_{m}$)$_{exp}$ by 60%. It is speculated that when the temperature difference between cooled surface and saturated vapour is small, temperature profile in a liquid film is quadratic.quadratic.. quadratic.quadratic..atic..

• Journal of Biosystems Engineering
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• v.13 no.2
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• pp.46-50
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• 1988

The estimation of beam radiation intensity on a tilted surface is very important to the design of a solar energy system. In order to get the beam radiation intensity, it is required to calculate the ratio of the diffuse solar radiation to the global radiation ($k_d$). The data measured at Chung-Buk National University. Cheong-ju, (from May 16, 1985 to Nov, 10, 1987) were analysed to define the relationship between hourly clearness index ($k_t$) and diffuse ratio ($t_d$). The results are is follow: 1. The percent of clearness index($k_t$) of less than 0.3 and of more than 0.8 were 2.7% and 3.1% respectively, and between 0.5 and 0.8 was 76.5%. 2. The regression equation between $k_t$ and $k_d$ was an exponential function as: $$k_d=\[{1\hspace{120}:\hspace{10}(k_t<0.1)\\1.28{\times}0.074^{k_t}\hspace{30}:\hspace{10}(0.1{\leq}=k_t<0.9)\\0.12\hspace{98}:\hspace{10}(0.9{\leq}=k_t)$$ There was a little difference between the result. of this study based on the data of 30 months and the results of previous study (ITRA 2(1):42-47, 1986.) based on the data of 8 months. 3. The hourly exponential regression equation between $k_t$ and $k_d$ was $k_d=A{\times}8^{k_t}$ and the values of constant A and coefficient B of the: equations are as the following table; 4. The percent of $k_d$ of less than 0.4 was 72.9% and of more than 0.7 was 6.6%. 5. Total mean value of $k_t$ and $k_d$ wert 0.56 and 0.32, respectively. From 10:00 to 15:00 o'clock the total mean value of $k_t$ was smaller that the hourly man value of $k_t$ and the one or $k_d$ larger.

• Fire Science and Engineering
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• v.14 no.3
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• pp.6-12
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• 2000

This paper describes the smoke movement of a fire field model based on a self-developed SMEP(Smoke Movement Estimating Program) code to the simulation of fire induced flows in the two types of compartment space containing the radiation effect under smoke movement in room fire. The SMEP using PISO algorithm solves conservation equations for mass, momentum, energy and species, together with those for the modified k-$\varepsilon $ turbulence model with buoyancy term. Also it solves the radiation equation using the discrete ordinates method. The result of the calculated smoke temperature containing radiation effect has shown reasonable agreement compared with the experimental data. On the other hand, a difference of a lot was found between the temperature predicted by the SMEP with only convection effect and obtained by the experimental result. This seems to come from the radiation effect of $H_2$O and $CO_2$ gas under smoke productions. Thus, the consideration of the radiation effect under smoke in fire may be necessary in order to produce more realistic result.

• Geomechanics and Engineering
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• v.10 no.3
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• pp.357-386
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• 2016

In this research work, an exact analytical solution for thermal stability of solar functionally graded rectangular plates subjected to uniform, linear and non-linear temperature rises across the thickness direction is developed. It is assumed that the plate rests on two-parameter elastic foundation and its material properties vary through the thickness of the plate as a power function. The neutral surface position for such plate is determined, and the efficient hyperbolic plate theory based on exact neutral surface position is employed to derive the governing stability equations. The displacement field is chosen based on assumptions that the in-plane and transverse displacements consist of bending and shear components, and the shear components of in-plane displacements give rise to the quadratic distribution of transverse shear stress through the thickness in such a way that shear stresses vanish on the plate surfaces. Therefore, there is no need to use shear correction factor. Just four unknown displacement functions are used in the present theory against five unknown displacement functions used in the corresponding ones. The non-linear strain-displacement relations are also taken into consideration. The influences of many plate parameters on buckling temperature difference will be investigated. Numerical results are presented for the present theory, demonstrating its importance and accuracy in comparison to other theories.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1195-1200
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• 2008

This study have goal with conceptual design for Offshore Structures of high pressure control valve for localization. Ball valve for development accomplished with flow analysis based on provision of ANSI B16.34, ANSI B16.10, ANSI B16.25 In order to localize the Offshore Structures high pressure control valve. Numerical simulation using CFD(Computational Fluid Dynamic) in order to predict a mass flow rate and a flow coefficient form flow dynamic point of view. The working fluid assumed the glycerin($C_3H_8O_3$). The valve inlet and outlet setup a pressure boundary condition. The outlet pressure was fixed by atmospheric pressure and calculated until increasing 1bar to 10bar. CFD analysis used STAR-CCM+ which is commercial code and Governing equations were calculated by moving mesh which is rotated 90 degrees when ball valve operated opening and closing in 1 degree interval. The result shows change of mass flow rate according to opening and closing angle of valve. Flow decrease observed open valve that equal percentage flow paten which is general inclination of ball valve. Relation with flow and flow coefficient can not be proportional according to inlet pressure when compare with mass flow rate. Because flow coefficient have influence in flow and pressure difference. Namely, flow can be change even if it has same Cv value. The structural analysis used ANSYS which is a commercial code. Stress analysis result of internal pressure in valve showed lower than yield strength. This is expect to need more detail design and verification for stem and seat structure.

• Journal of the Korean Dietetic Association
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• v.15 no.1
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• pp.52-68
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• 2009

This study compared activity factor. predicted resting metabolic rate (RMR), and nutrient intakes between athletic and non-athletic high school students in Gangwon-do. Fifty soccer players (30 males and 20 females; mean ages 16.7${\pm}$1.0 years and 16.4${\pm}$1.1 years. respectively) and 50 non-athletic (30 males and 20 females: mean ages 17.5${\pm}$0.4 years and 16.4${\pm}$1.1 years respectively) high school students were included. Anthropometric measurements included: weight and height. triceps skinfold, mid-ann circumference, and body fat. Prediction equations consisted of those from the Harris-Benedict. FAO/WHO/VNU, IMNA, Cunningham, Mifflin et al., and Owen et al. A one-day activity diary was collected by interview, and the 24-hour recall method was used to analyze nutrient intakes of subjects. The activity factors of the male and female athletic groups (2.23 and 2.16, respectively) were significantly higher than those (1.52 and 1.46, respectively) of the non-athletic group. There was only a significant difference in RMR by use of the Cunningham's equation between two groups. For the males. almost all nutrient intakes of the athletic group (except carbohydrate, iron, vitamin $B_1$, $B_6$, and niacin) of athletic group were significantly higher than those of the non-athletic group. The female athletic group showed significantly higher nutrient intakes with the exception of most vitamins. These results suggest that assessments of energy balance between energy intake and energy expenditure by employing RMR and activity factors would be useful to prevent and treat obesity in high school athletes. In addition, the Cunningham's equation would be appropriate for predicting their energy needs.

• Journal of Korea Water Resources Association
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• v.50 no.9
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• pp.637-646
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• 2017

This study presents a numerical model for simulating dense interflows. The governing equations are provided and the finite difference method is used with the $k-{\varepsilon}$ turbulence model. The model is used to simulate a dense interflow established in a deep ambient water, resulting velocity and excess density profiles. It is observed that velocity decreases in the longitudinal direction due to water entrainment in the vicinity of the outlet and rarely changes for increased Richardson number. Similarity collapses of velocity and excess density are obtained, but those of turbulent kinetic energy and dissipation rate are not. A shape factor for the dense interflow is obtained from the simulated profiles. The value of this shape factor can be used in the layer-averaged modeling of dense interflows. In addition, a buoyancy-related parameter ($c_{3{\varepsilon}}$) for the $k-{\varepsilon}$ model and the volume expansion coefficient (${\beta}_0$) are obtained from the simulated results.