• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.234-238
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• 1996

The purpose of this study was to determine whether vitamin {TEX}$B_{6}${/TEX} deficiency and age affect the blood cho-lesterol profile in exercising rats. Fifty four rats were fed either a viramin {TEX}$B_{6}${/TEX} deficient dief(-{TEX}$B_{6}${/TEX}) of a control diet(+{TEX}$B_{6}${/TEX}) for 6 weeks, then subdivided into 3 groups:non-exercise group(NE), exercise and sacrifice group(ES), exercise and recuperation group(ER). ES group was exercised in treadmill({TEX}$10^{o}${/TEX}, 0.5~0.8km/h) for 2 hours and sacrifice. ER group was recuperated three days with respective diet after exercise. At week 3 and 6, and level of plasma total cholesterol(TC), high density lipoprotein cholesterol(HDL_C) and low density lipoprotein cholesterol(LDL_C) were compared. In NE group, there was no difference in the levels of TC, HDL_C and LDL_C between +{TEX}$B_{6}${/TEX} rats and -{TEX}$B_{6}${/TEX} rats. The plasma levels of TC and LDL_C of 6 weeks were higher than those of 3 weeks and on difference in HDL_V between 3 weeks rats and 6 weeks rats. In ES group, there was also no difference in the levels of TC, HDL_C and LDL_C between +{TEX}$B_{6}${/TEX} rats and -{TEX}$B_{6}${/TEX} rats and there was no difference in TC, LDL-cholesterol between 3 weeks rats and 6 weeks rats. The level of HDL_C pf 6 weeks was lower than that of 3 weeks rats. In ER group, there was no difference in the levels of TC and LDL_C not only between +{TEX}$B_{6}${/TEX} rats and-{TEX}$B_{6}${/TEX} rats but also between 3 weeks rats and 6 weeks rats. The level of HDL_C was lower in -{TEX}$B_{6}${/TEX} rats than in +{TEX}$B_{6}${/TEX} rats and higher in 6 weeks rats than in 3 weeks rats. These results suggest that vitamin {TEX}$B_{6}${/TEX} deficiency may affect the HDL_C during exercise and after recuperation. The desirable effect of exercise on plasma Cholesterol profile is strengthened in adult age than young age.

• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.214-218
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• 1997

The purpose of this study was to investigate the potential hypolipidemic effect of job's tears diet with the controlled intake of fiber in streptozotocin induced diabetic rats. Forty eight rats were fed either control diet or experimental diets (Raw, milled job's tears(RMJ); Raw, whole grain job's tears(RWJ);Steamed, milled job's tears(SMJ);Roasted, milled job's tears(OMJ)) for 3 weeks. The levels of total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), free fatty acid(FFA) and triglyceride (TG) in plasma, liver and skeletal muscle were compared. Compared to diabetic control group, the level of plasma TC was lower in OMJ an SMJ fed rats, and was not different from that in RMJ and RWJ fed rats. The level of LDL-C was significantly lower in RMJ, OMJ and SMJ fed rats. For plasma HDL-C levels, no difference was observed among all group. Plasma FFA level significantly lower in RMJ, SMJ and RWJ fed rats, Plasma TG a levels of all job's ears fed groups were 50∼70% lower and liver TG levels of all job's tears fed groups were 70∼80% lower than those fo diabetic control group. For muscle TG, no differences were seen among all groups. These results suggest that steamed job's tears and roasted job's tears could have the potentaila on improving lipid profile fo diabetes in clinical setting and the different cooking methods of job's tears might affect the lipid profile of the diabetic rats.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.600-603
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• 2000

DNA chip containing 207 E. coli genes related to important metabolisms such as (TCA cycle, glycolysis, fermentation and etc) were used to carry out a comprehensive investigation of the change in metabolism and physiology during high cell density culture of E. coli by fed-batch cultivation.

• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.35-35
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• 2004

Inhomogeneity Is important in wave coupling and mode conversion. We numerically examine the conversion of extraordinary(X) waves into upper hybrid(UH) waves in inhomogeneous plasmas by using a three-dimensional multi-fluid numerical model. A one-dimensional Inhomogeneous density profile is assumed in a cold and collisionless plasma. The density gradient is taken to be perpendicular to the magnetic field. An impulsive input is assumed to excite the X waves in the inhomogeneous box model. (omitted)

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.577-580
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• 1999

High power density on-board power supply is implemented by using flat transformer. In the high frequency switching converters, large leakage inductance increases the switching stress and duty cycle loss, which sometimes limits maximum switching frequency. The flat transformer is designed by using special core structure, which has very low profile and low temperature rise since the thermal loading is spread evenly over a larger area. 100W, 3.3V output on board supply is built and tested and 50.7W/$\textrm{inch}^{3}$ power density is achieved.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.314-317
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• 2005

There are many benefits such as increased areal density, reduced power consumption, applied smaller size and improved shock resistance in Load/Unload(L/UL) mechanism. It has been the key technology of developing small form factor hard disk drive used in portable digital devices. The main objectives of L/UL are no slider-disk contact and faster L/UL process. For realizing those, we must consider many design parameters in L/UL systems. In this paper, we focus on the effects of ramp profile. We can investigate dynamic characteristics of suspension tap and slider on ramp during unloading process experimentally. In special, we examine the effects of vortical velocities, ramp slopes and disk vibrations. As the result of these experiments, we propose design criteria of advanced ramp profile for good unloading performance.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.228-235
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• 2008

Nickel plating thickness increased with the electric current density, and the augmentation was more thick in $6{\sim}10A/dm^2$ than low current. Hull-cell analysis was tested to evaluate the current density. Optimum thickness was obtained at a temperature of $60^{\circ}C$, and the pH fluctuation of 3.5~4.0. Over the Nickel ion concentration of 300 g/L, plating thickness increased with the current density. The rate of decrease in nickel ion concentration was increased with the current density. The quantity of plating electro-deposition was increased at the anode surface, which was correlated with the increase of plating thickness. The plating thickness was increased because of the quick plating speed. However, the condition of the plating surface becomes irregular and the minuteness of nickel plating layer was reduced with the plating rate. After the corrosion test of 25 h, it was resulted in that maintaining low electric current density is desirable for the excellent corrosion resistance in lustered nickel plating. According to the program simulation, the thickness of diffusion layer was increased and the concentration of anode surface was lowered for the higher current densities. The concentration profile showed the regular distribution at low electric current density. The field plating process was controlled by the electric current density and the plating thickness instead of plating time for the productivity. The surface physical property of plating structure or corrosion resistance was excellent in the case of low electric current density.

• Journal of the Korean Wood Science and Technology
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• v.30 no.1
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• pp.25-33
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• 2002

Improvement of density profile and sound absorption capability of particleboard was attempted. Three types of hot pressing methods examined ; flat-platen pressing method (A-type pressing), hot pressing in forming box (B-type pressing), and hot pressing set up jagged caul in forming box (C-type pressing). The raw materials were larch(Larix leptolepis (S, et. Z.) Gorden) shavings, phenol formaldehyde resin, and the particleboard perforated with stair type. The physical and mechanical properties such as specific gravity, bending strength (MOR), internal bonding strength (IB) and sound absorption coefficients were examined. The results are summarized as follows : 1) The MOR and internal bonding strength of the board pressed in forming box were higher than those of flat-platen pressed board. 2) The minimum density to average density ratio in thickness direction which pressed in forming box showed about 923%, in the case of 35 mm commercial particleboard and 50 mm flat-platen pressed board, its values showed about 66.4% and 865% respectively. 3) Sound absorption coefficients of the particleboard perforated with stair type were higher than those of flat-plated pressed board and commercial particleboard.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.6
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• pp.535-541
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• 1999

Low-dislocation-density large-diameter GaAs single crystals with low-residual-strain have been strongly required. We have developed dislocation-free 3-inch Si doped GaAs crystals for photonic devices, and low-dislocation-density low-residual-strain 4-inch to 6-inch semi-insulating GaAs crystals for electronic devices by Vertical Bridgman(VB) technique. We confirmed that VB substrates with low-residual-strain have higher resistance against slip-line generation during MBE process. VB-GaAs single crystals show uniform radial profile of resistivity reflecting to the flat solid-liquid interface during the crystal growth. Uniformity of micro-resistivity of VB-GaAs substrate is much better than of the LEC-GaAs substrate, which is due to the low-dislocation-density of VB-GaAs single crystals.

• Journal of Power System Engineering
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• v.21 no.1
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• pp.43-49
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• 2017

This work aims to investigate on the low cycle fatigue life assessment, which is adopted on the strain-life relationship, or better known as the Coffin-Manson relationship, and also the strain energy density-based model. The low cycle fatigue test results of Alloy 617 weldments under $900^{\circ}C$ have been statistically estimated through the Coffin-Manson relationship according to the provided strain profile. In addition, the strain energy density-based model is proposed to represent the energy dissipated per cycle as fatigue damage parameter. Based on the results, Alloy 617 weldments followed the Coffin-Manson relationship and strain energy density-based model well, and they were compatible with the experimental data. The predicted lives based on these two proposed models were examined with the experimental data to select a proper life prediction parameter.