• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.171-178
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• 2008

In the methanol extract from safflower seeds, two kinds of antioxidant were detected by preparative HPLC [$\mu$-Bondapak $C_{18}$ column ($7.8{\times}300\;mm$)]. Two unknown compounds were defined as CA and CB which had peaks at 22.1 min and 24.5 min, respectively. Antioxidant activity was measured by their scavenging ability on the stable tree radical of 1,1-diphenly-2-picrylhydrazyl (DPPH). For bulk extraction of antioxidants, the methanol extract was fractionated with hexan, chloroform, ethyl acetate and butanol. The ethyl acetate traction showing the highest DPPH radical scavenging activity was further purified by silica gel column chromatography to CA and CB. By NMR analysis, CA and CB were identified as N-(p-Coumaroyl)serotonin and N-feruoylserotonin, respectively. The content of N-(p-Coumaroyl)serotonin and N-feruoylserotonin were analyzed by reverse phase HPLC using a $\mu$-Bondapak $C_{18}$ column ($3.9{\times}300\;mm$) with linear gradient elution from 10% acetonitrile to 50% acetonitrile for 30min on UV detector at 300 nm. The contents of N-(p-Coumaroyl)serotonin and N-feruoylserotonin were 4.11 mg/g DW and 7.29 mg/g DW, respectively, and these two DPPH radical scavengers were detected only in the hull of seeds.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.2
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• pp.153-159
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• 2012

This study gives the vertical motion analysis in multi-directional irregular waves using a commercial code(MAXSURF v.16) based on linear strip theory for a training ship. To verify the commercial code prior to the analysis, we guarantees the reliability of this paper's results using the commercial code by comparing with the results(Flokstra, 1974) of same hull and experimental conditions on a Panamax container. The analysis conditions are Beaufort wind scale No. 5($\bar{T}=5.46$, $H_{1/3}=2m$) based on ITTC wave spectrum, encounter angle Head & bow seas($150^{\circ}$) and Froude number Fn=0.257. Finally, we calculates heave RAO, pitch RAO and obtains the result of ship's response spectra for heave and pitch motions. In the motion response spectrum under the multi-directional irregular waves, heave motion reacts slightly high in short-crested waves and pitch motion reacts high in long-crested waves.

• Journal of Biosystems Engineering
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• v.2 no.1
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• pp.7-24
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• 1977

This paper is the forth and fifth one of the study on balanced type oscillating mole drainer. In the light of the results from previous reports about the model tests, some design criteria were established and a prototype machine was set up for experimental purpose. Motion characteristics and functionof the each parts of the machine were checked and analyzed. After that, performance tests of the prototype machine were carried out in thefield. Obtained results are summarized as follows ; 1. Ten centimeter of the bullet diameter was determined so as to be able to attach it to the tractors with capacity of 30 PS to 40 PS. 2. To maintain the balance between the moments of the front shank and rear shank, the oscillating amplitude of the rear bullet was determined to be larger than that of the front bullet. At the same time , the oscillating direction of the rear bullet was designed with the inclines of ten to thirty degrees. 3. An octagonal dynamo transduced was developed for measuring the compressive force of the upper link is measuring the draft force of the machine. Acceptable linear relationship between forces and strain responses from O.D.T. was obtained. 4. Analysing the balancing mechanism of the acting part of the machine , it was found that the total draft force of the machine was equal to the difference between the sum of the draft force produced from the right and left side bending moments of the lower drawber and the compressive force on the upper link. 5. There are acceptable linear relationship between the strain and twisting moment by driving shaft, and between strain and shank moment. Above results enable us to carry out the field experiment with prototype machine. 6. When the test machine was used in the field, it was possible to reduce the oscillating acceleration by forty percent in average as compared it with the single bullet mole drainer. 7. When the test machine was used under the oscillating condition, the dratt torce was reduced by 27 percent to 59 percent as compared it with the test machine under non-oscillating condition, while the draft force was increased by 7 percent to 20 percent as compared it with the mole drainer having oscillating single bullet. The reasoning behind this fact was considered as the resistance force due to the rear shank and bullet. 8. As the amplitude and frequency of the bullet were increased, the torque was increased accordingly. This tendency could be varied with the various characteristics of the given soils. And the larger frequency and amplitute, the more increasing oscil\ulcornerlating power but decreasing draft brce were needed, and draft force was increased as the velocity was increased.9. When the amplitude of the rear bullet was designed to be larger than that of the front bullet, the minimum value of the moment was lowered and oscillating acceleration was reduced. And when the oscillating direction of the rear bullet was declined back\ulcornerwards, oscillating acceleration was increased along with the increasing angle of decli\ulcornernation. When the test machine was operated in high speed, the difference between maximum moments and minimum ones became narrow. This varying magnitude of moments appeared on the moment oscillogram seems to be correlated to the oscillating acceleration and draft force. 10. From the analysis of variance, it was found that those factors such as frequency, amplitude, and operating velocity significantly affected in the oscillating acceleration, the draft resistance, the torque, the moment, and the total power required. And interaction between frequency and amplitude affected in the oscillating acceleration. 11. Within the given situation of this study, the most preferable operating conditions of the test machine were 7 Hz in oscillating frequency, 0.54 m/sec in operating velocity, and 39.1 mm in oscillating amplitude of front and rear bullets. However, it is necessary to select the proper frequency and magnitude of oscillation depending on the soil properties of the field in which the mole drainer is practiced by use of a bal1nced type oscillating mole drainer. 12. It is recommended that a comparative study of the mole drainers would be performed in the near future using two separate balanced oscillating bullet with the one which is operated by oscillating the movable bullet in a single cylinder or other balanced type which may be single oscillating bullet with spring, damper or balancing weight, and that of thing. To expand the applicability of the balanced type oscillating mole drainer in practical use, it is suggested to develop a new mechanism which perform mole drain with vinyl pipe or filling material such as rice hull.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.21 no.2
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• pp.131-136
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• 1985

The calculation of the resulting fluid motion is an important problem of ship hydrodynamics. For a partially immersed body the condition of constant pressure at the free surface can be linearized. The resulting linear boundary-value problem for the velocity potential is the Neumann-Kelvin problem. The two-dimensional Neumann-Kelvin problem is studied for the half-immersed circular cylinder by Ursell. Maruo introduced a slender body approach to simplify the Neumann-Kelvin problem in such a way that the integral equation which determines the singularity distribution over the hull surface can be solved by a marching procedure of step by step integration starting at bow. In the present pater for the two-dimensional Neumann-Kelvin problem, it has been suggested that any solution of the problem must have singularities in the corners between the body surface and free surface. There can be infinitely many solutions depending on the singularities in the coroners.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.196-203
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• 2006

Objective of this research was to determine the effect of application level of fused superphosphate (FSPP) in root media containing granular micronutrient fertilizers (MF) on growth of marigold 'Orange boy' in plug culture. To achieve this, three granular micronutrient mixes such as MF 1, MF 2, and MF 3 were produced and incorporated into three root media, peatmoss+composted pine bark (1:1, v/v, PB), peatmoss+composted rice-hull (1:1, v/v, PR), and peatmoss+composted saw-dust (1:1, v/v, PS), at a rate of $0.3g{\cdot}L^{-1}$. Elevated application level of FSPP in PS medium containing each of MF resulted in increase of plant growth such as plant height, plant width, stem diameter, fresh weight and dry weight at 35days after sowing. The dry weight in the treatment of MF 1, MF 2, MF 3, and control fertilized with $9.0g{\cdot}L^{-1}$ of FSPP were 0.066g, 0.103g, 0.077g, and 0.095g per plant, respectively. These results indicated that each of MF affected marigold plug seedlings differently. The application level of FSPP resulted in the heaviest fresh and dry weight in PR medium were $9.0g{\cdot}L^{-1}$ in MF 1, $3.0g{\cdot}L^{-1}$ in MF 2, $9.0g{\cdot}L^{-1}$ in MF 3, and $6.0g{\cdot}L^{-1}$ in control. Elevated application level of FSPP in PB medium containing each of the micronutrient mix increased fresh and dry weight. The general trends in response of plant growth to elevated FSPP were linear and quadratic. The dry weight in the treatment of MF 1, MF 2, MF 3, and control fertilized with $9.0g{\cdot}L^{-1}$ of FSPP in PB medium were 0.131g, 0.104g, 0.137g, and 0.111g per plant at 35days after sowing. These results indicated that MF 1 and MF 3 performed better than MF 2 and control treatments in growth of marigold plug seedlings.