Organic scintillator is easy to manufacture a large size and the fluorescence decay time is short. However, it is not suitable for gamma measurement because it is composed of a low atomic number material. Organic scintillation detectors are widely used to check the presence or absence of radiation. The fluorescence of organic scintillators is produced by transitions between the energy levels of single molecules. In this study, an organic scintillator development study was conducted for use in gamma measurement, alternative materials for secondary solute used in basic organic scintillators were investigated, and the availability of alternative materials, detection characteristics, and neutron/gamma identification tests were performed. In other words, a secondary solute showing an improved energy transfer rate than the existing material was reported, and the performance was evaluated. 7-Diethylamino -4-methylcoumarin (DMC), selected as an alternative material, is a benzopyrone derivative in the form of colorless crystals, has high fluorescence and high quantum yield in the visible region, and has excellent light stability. In addition, it has a large Stokes shift characteristic, and solubility in solvent is good. Through this study, it was analyzed that the absorption wavelength range of DMC coincided with the emission wavelength range of PPO, which is the primary solute. Through this study, it was confirmed that the optimal concentration of DMC was 0.04wt%. As a result of performing gamma and neutron measurement tests using a DMC-based liquid scintillator, it showed good performance (FOM=1.42) compared to a commercial liquid scintillator. Therefore, the possibility of use as a secondary solute was demonstrated. Based on this, if studies on changes in the composition of secondary solute or the use of nanoparticles are conducted, it will be possible to manufacture and utilize a scintillator with improved efficiency compared to the existing scintillator.

When kimchi is frozen and thawed, the amount of lactic acid bacteria (LAB) and yeast is usually reduced by more than 2 logs, and its texture including its crispness and hardness are changed significantly. As a possible means to minimize these problems, various freezing (direct freezer with -25, -40, and -60oC and plate freezer with -40oC) and thawing methods (radio frequency (RF) thawing, plate thawing, and room temperature thawing) were investigated in terms of the amount of LAB and texture of kimchi. From the use of plate freezing and plate thawing, the amount of LAB of white cabbage kimchi could be maintained by more than 10% of its initial amount while that for red cabbage kimchi could be maintained by more than the initial amount. Pretreatment with trehalose (19 oBrix soluble solid content) to salted Chinese cabbage could maintain kimchi’s hardness and crispness. In order to maintain the texture and the amount of LAB in kimchi, the use of the plate freezer (-40oC) and the plate thawing (20oC) seemed to be effective with the assistance of trehalose.

Commercial direct refrigerators have good energy efficiency, but are difficult to use for supercooled storage due to their large temperature deviation. Placing insulators and conductors inside the refrigerator could reduce these temperature deviations to within 0.3 degrees, allowing for the supercooled storage. The supercooled storage of salted Chinese cabbages during ten weeks was progressed to compare the other low temperature storages. The nucleation temperatures of salted Chinese cabbage were around -2.5oC and the freezing points were around -0.4oC, so -2oC was selected for the supercooled storage. The growth rate of lactic acid bacteria and yeast at -2oC storage was lower than that at 2oC storage. The reducing sugar was maintained higher due to the growth rate of lactic acid bacteria. The supercooled storage had an effect of delaying the fermentation of the salted Chinese cabbage, which may have the effect of delaying the fermentation of kimchi. This enhancement method of the direct refrigerator was effective for the supercooled storage and would be promising for commercial use.

For the vessel export of strawberries, modified atmosphere package (MAP) using polyamide (PA) film and linear low density polyethylene (LLDPE) film was investigated to extend the shelf life of strawberries. Because the temperature and relative humidity changes of the MAP were lower than the changes of the control, the weight loss of the MAP were lower than that of the control. The low oxygen level and high carbon dioxide level were effective to decrease the fungal decay rate and to increase the hardness of strawberries. The Hunter’s color differences before and after storage showed no distinct difference between the MAP and the control. The lightness had a tendency to decrease while the redness increased. There were no significant changes of the soluble solids during the storage. The shelf life of strawberries could be extended to 16 days using the MAP considering the weight loss and the fungal decay rate. Thus, this MAP method using PA film and LLDPE film was effective to extend the shelf life of strawberries.

The main purposes of this study were to identify the factors affecting the supercooling property and to improve the possibility of supercooling storage of fruits and vegetables. Freezing point and nucleation temperature, moisture content, hardness, sugar content, and pH of nineteen fruits and vegetables were measured and Pearson correlation analysis was performed. Freezing point showed a statistically significant correlation with moisture content and sugar content (p<0.01), while ice nucleation temperature showed a correlation (p<0.05) only for sugar content. In particular, the water content and sugar content did not show any correlation with the freezing supercooling difference (FSD). From the correlation analysis between FSD, aerobic bacteria, lactic acid bacteria, yeast, and mold, FSD showed a correlation (p<0.01) with aerobic bacteria. The experiments of the saline solutions inoculated with aerobic bacteria at different concentrations showed FSDs of about 2 for saline inoculated with 9.4 log CFU/mL and about 6 for saline inoculated lower than 5 log CFU/mL. Therefore, the aerobic bacteria concentration was determined to be a key factor affecting the supercooling storage of fruits and vegetables.

The variations of internal temperature, relative humidity (RH) and gas concentration in the pallet modified atmosphere package (MAP), using polyamide (PA) film and linear low density polyethylene (LLDPE) film, were investigated to extend the shelf life of tomatoes and paprikas. The temperature and RH inside the MAP were higher than that in the cold room, but there was no water condensation inside the MA film. The ethylene concentration in the MAP was maintained below 10 ppm. Oxygen level was stabilized at 2 to 5% during the storage and carbon dioxide level was also stabilized at 15 to 20%. The weight loss of the MAP tomatoes and paprikas was lower than that of the control because the RH in the pallet MAP was higher than that of the cold room. The fungal decay rate in the pallet MAP was also lower than that in the control due to a low oxygen concentration rate. There were no significant differences in the soluble solids, titratable acidity and Hunter’s color, but differences did exist in the hardness between the MAP and the control. So, this pallet MAP method was effective at extending the shelf life of tomatoes and paprikas considering the weight loss, fungal decay and hardness.

The purpose of this study was to test the effect of Gastrocnemius and Low Back-muscle isotonic exercise on static•dynamic standing balance during the period of 4 weeks. This study was two groups pretest-posttest design. Nineteen subjects who were over 22 years old were randomly assigned to either the experimental group that received the Gastrocnemius muscle exercise(n=9) or the low back muscle exercise(n=10) : The former group performed isotonic exercise(plantar flexion), the latter group performed isotonic exercise(trunk extension) a total of 18 times for three times per week for four weeks. Two groups also performed static and dynamic balance before the exercise and 4weeks after the exercise. The data were analyzed by using the paired t-test and independent t-test. The results were as follows: As compared with change of dynamic balance performance capacity at two groups, a significant difference was shown in the test(p<.05), but not in static balance(p>.05). Also, a significant difference of balance between groups was not shown in the test. In this study indicated that gastrocnemius and low back muscle isotonic exercise will have positive impact on standing balance.

The purpose of this study is to analyze the correlation between the stature and the muscle performance ratings and the subjective discomfort rations at performing lower arm's pronation and supination according to change sin the height of working table for more efficient performance at designing a working table and performing a work. For the purpose, this study conducted an experiment targeting 40 people in their 20s, who were classified into 4 groups each group composing 10 people at intervals of 5cm from the standard stature of 166.5cm. The experiment measured the maximum isometric pronation and the supination muscular power, and at measuring the factors, the heights of working tables were set as 800mm, 850mm, and 900mm. From the measurement results, it was found that the stature and the maximum muscular power was correlated. That is, as the experiment groups's average stature is higher, the maximum muscular power was higher. For the correlation between the motion patterns(pronation and supination) and the maximum muscular power, it was seen that the maximum muscular power was higher at performing the pronation than the supination. In the correlation between motion patterns and the subjective discomfort ratings, it was seen that the subjective discomfort rating was higher at performing the supination than the pronation. For the correlation between height adjustment and the subjective discomfort ratings, as the height of working table was lower, the subject discomfort rating was lower. Therefore there was no difference in the maximum muscular power according to the height changes of working table, but it was found that as the working table was higher, the user felt more comfortable.

The purpose of this study was to comparatively analyze the active stability of shoulder joints according to the frequency of overhead motions, such as serving and spiking, engaged in by female professional volleyball athletes who play different positions, and to provide the results as the basic data for developing exercise programs to prevent shoulder joint injuries. The subjects of this study were 50 Korean female professional volleyball players and positions were as follows: left and right attackers, centers, setters, and liberos. The external rotation and internal rotation muscle strength and muscle strength ratios of the dominant and non-dominant arms of all subjects were measured using Biodex. The results of this study are as follows: Frist, no significant differences were found in the internal and external rotation muscle strength of the dominant and non-dominant arms between positions. Second, for the shoulder joint muscle strength ratio of the dominant arm, by position, the setter showed significantly greater stability compared to the other positions. Third, for the shoulder joint muscle strength ratio of the non-dominant arm, by position, no significant difference in stability between positions was found. Fourth, it was found that the dominant arm had significantly greater instability of the shoulder joint than the non-dominant arm for attackers and centers, but no significant difference was found for setters and liberos. This study comparatively analyzed the muscle strength ratios of the external/internal rotations and dominant/non-dominant arms, which can determine the stability of the shoulder joints between female professional volleyball playing positions that engage in jumps and spikes using only the dominant hand and positions that do not.

This study has been conducted on the subjects of eight undergradu˗ ate students with abdominal obesity and eight undergraduate stu˗ dents with normal weight to find out correlation between substantial fatigue and Ratings of perceived exertion through analysis of their blood components when they took exercises to strengthen their abdominal muscular power. Comparatively analyzing HDL-C, LDL-C and lactic acid before and after they took sit-up at level of RPE 19-20, no statistically significant differences in HDL, LDL, lactic acid meas˗ ures were observed between groups, but a significant difference in RPE was noted between groups(p<0.05) Our findings suggest that control group showed no significant differ˗ ence in increase of fatigue material whereas the obese group showed a lower frequency of sit-up, though both groups took the same abdominal exercise. Additionally, the lower frequency of sit-up in obese group results from relatively higher Ratings of perceived exer˗ tion rather than increase of substantial fatigue material. This study invites future research that examines the effect of a comprehensive obesity exercise program combined with dietetic

Cementum is the mineralized tissue of the tooth. It is similar to bone in several aspects but it differs from bone. Human bone marrow stromal cells (BMSC) and human cementum derived cells (HCDC) (10,000 cells/cm²) were plated in 6 well plates as feeder cells. The next day, mouse bone marrow cells (1.5 million cells/cm²) were added. One group of these plates were incubated in serum-free conditioned medium (SFCM) generated from BMSC or HCDC supplemented with 2% FBS, parathyroid hormone (PTH), 1, 25 dihydroxyvitamin D₃ (Vit. D₃) and dexamethasone, or plain medium with the same supplements. Another group of plates were cocultured with BMSC or HCDC in plain medium supplemented with 2% FBS, PTH, Vit. D₃and dexamethasone. Plates grown without SFCM or coculture were used as controls. After 10 days, the cells were stained for tartrate-resistant acid phosphatase (TRAP). BMSC were found to support osteoclast formation under normal conditions. This was inhibited however by both SFCM generated from HCDC and also by coculture with HCDC. In addition, HCDC themselves did not support osteoclast formation under any conditions. Our results thus indicate that HCDC do not support osteoclast formation in vitro and that soluble factor (s) from HCDC may inhibit this process. In addition, we show that this inhibition also involves an active mechanism that is independent of osteoprotegerin, a feature that may distinguish cementoblasts from other cells present in periodontium.

The effect of packaging materials on the quality and physiological activity of Angelica acutiloba leaves during storage at 4℃ for 20 days and after being transferred to room temperature for 2 days was studied. The experiment was conducted using three packaging materials: the corrugated box (control); corrugated box with 20 ㎛ HDPE perforated film liner; and corrugated box with paraffin wax coated paper + 20 ㎛ HDPE perforated film liner. Changes in weight, color, aroma, overall visual quality, antioxidant activity, and total flavonoids were investigated. Based on the result, the treatments using corrugated box with 20 ㎛ HDPE perforated film liner and the corrugated box with paraffin wax coated paper + 20 ㎛ HDPE perforated film liner, were effective in minimizing weight loss, and maintaining external color and overall quality as compared to corrugated box only (control). The corrugated box with paraffin wax coated paper + 20 ㎛ HDPE perforated film liner was more effective in maintaining antioxidant activity and total flavonoids than other treatments. Prolonging the freshness using corrugated box with paraffin wax coated paper + 20 ㎛ HDPE perforated film liner could increase the marketability of Angelica acutiloba leaves in the domestic market.