• Journal of Korean Society of Environmental Engineers
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• v.37 no.5
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• pp.253-261
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• 2015

In this study, Chlorophyll-a (chl-a) prediction model and multiple parameters affecting algae occurrence in Mulgeum site were evaluated by statistical analysis using water quality, hydraulic and climate data at Mulgeum site (1998~2008). Before the analysis, control chart method and effect period of typhoon were adopted for improving reliability of the data. After data preprocessing step two methods were used in this study. In method 1, chl-a prediction model was developed using preprocessed data. Another model was developed by Method 2 using significant parameters affecting chl-a after data preprocessing step. As a result of correlation analysis, water temperature, pH, DO, BOD, COD, T-N, $NO_3-N$, $PO_4-P$, flow rate, flow velocity and water depth were revealed as significant multiple parameters affecting chl-a concentration. Chl-a prediction model from Method 1 and 2 showed high $R^2$ value with 0.799 and 0.790 respectively. Validation for each prediction model was conducted with the data from 2009 to 2010. Training period and validation period of Method 1 showed 20.912 and 24.423 respectively. And Method 2 showed 21.422 and 26.277 in each period. Especially BOD, DO and $PO_4-P$ played important role in both model. So it is considered that analysis of algae occurrence at Mulgeum site need to focus on BOD, DO and $PO_4-P$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.1
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• pp.41-46
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• 1994

This study was undertaken to clarify the effect of killing methods on physical and rheological changes of plaice, Paralichthys olivaceus muscle at early period after death. Plaices killed by the four different methods(1. spiking at the brain instantly. 2. drowning in air. 3. dipping in 1,000ppm ethylaminobenzoate dissolved sea water as an anesthetic. 4. electrifying in sea water.) were stored at $5^{\circ}C$, and the rigor-index and breaking strength through storage were monitored. The longest onset time of rigor-mortis and full rigor was in the samples killed by dipping in sea water with dissolved anesthetic among all samples, where rigor-mortis began at 20hrs after killing and maximum tension was attained after 56hrs. However, in the cases of plaice electrified in sea water or drowned in air, the onset of rigor-mortis began just after killing and maximum tensions were attained after 9hrs and 13hrs, respectively. The level of breaking strength in the muscle of fish killed by spiking the brain instantly was $950.30{\pm}50.23g$, immediately after killing. The value and time reached around the maximum breaking strength for each of the samples were $1,230.60{\pm}30.32g$ and Ohr (immediately after killing) for samples killed by electrifying in sea water, $1,235.83{\pm}35.37g$ and 2.5hrs for drowning samples, $1,186.29{\pm}55.90g$ and 10hrs for spiking samples, and $1,189.67{\pm}50.32g$ and 15hrs for samples dipped in anesthetic, respectively. From the results above, it could be concluded that electrification in sea water is the most effective method in accelerating rigor-mortis and shortening times of reaching the maximum breaking strength of fresh plaice flesh of all the killing methods at early periods after death, whereas dipping in sea water treated with anesthetic was the most effective way in delaying those changes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.393-407
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• 1997

A survey of biological and chemical characteristics in the middle-northern East Sea of Korea was carried out at 28 stations in October, 1995 on board R/V Tam-Yang. On the basis of the vertical profiles of temperature, salinity and dissolved oxygen, water masses in the study area were divided into 5 major groups; (1) Low Saline Surface Water (LSSW), (2) Tsushima Surface Water (TSW), (3) Tsushima Middle Water (TMW), (4) North Korean Cold Water (NKCW), (5) last Sea Porper Water (ESPW). Other 4 mixed water masses were also observed. It is highly possible that the LSSW which occured at depths of $0\~30m$ in the most southern part of the study area is originated from the Yangtze River (Kiang) of China due to very low salinity $(<32.0\%_{\circ})$ relatively high concentration of dissolved silicate and no sources of freshwater input into that area. Oxygen maximum layer in the vertical profile was located near surface at northern cold waters and became deeper at the warm southern area. Oxygen minimum layer af depths $50\~100m$, which is TMW, were found in only southern area. In the vortical profiles of nutrients, the concentrations were very low in the surface layer and increased drammatically near the thermocline. The highest concentration occurred in the ESPW. The relatively low value of Si/P ratio in the ESPW (13.63) compared to other reports in the East Sea was due to continuous increase of P with depth as well as Si. The N : P ratio was about 6.92, showing that nitrogenous nutrient is the limiting factor for phytoplankton growth. The exponential relationship between Si and P, compared to the linear relationship between N and P, indicates that nitrate and phosphate have approximately the same regenerative pattern, but silicate has delayed regenerative pattern.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.408-416
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• 2002

A 3D hydrodynamic-ecological coupled model was applied to estimate carrying capacity in Geoje-Hansan Bay where is one of the most important oyster culturing grounds in Korea. We considered the carrying capacity as the difference between food supply to the oysters and food demand, considering monthly difference of the actual growth. The food supply to the system was determined from the results of the model simulation (tidal exchange and chlorophyll $\alpha$) over the culturing period from September to May of the following year. The food demand was estimated from the food concentration (chlorophyll $\alpha$) multiple the filtration rate of oysters that is considered monthly different growth rate of oysters and food concentration. The values of carrying capacity for the system varied from 6.1 ton/ha (minimum carrying capacity) in february to 14.91 ton/ha (maximum carrying capacity) in April of marketable size oysters (>4 g wet-tissue weight) depending on temporal variations in the food supply. The oyster production calculated from present facilities was 9 ton/ha in wet-tissue weight in Geoje-Hansan Bay. This value corresponded to $60\%$ of maximum carrying capacity of the system. The optimal carrying capacity without negatively affecting on oyster production was 5.5 ton/ha when calculated from annual statistic data and 6.1 ton/ha when determined by this study. These results suggest that it must be reduced $32\%$~$39\%$ of oyster facilities in the system.

• Restorative Dentistry and Endodontics
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• v.31 no.6
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• pp.477-484
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• 2006

The purposes of this study were to compare the apical terminus width of simulated curved root canal prepared with three NiTi file systems used by undergraduates for evaluation the effects of flute angle and pitch or radial land on reducing screw-in effect and to determine more safe NiTi file system for inexperienced operators. Fifty inexperienced undergraduate students prepared 150 simulated curved root canals in resin blocks with three NiTi file systems ; ProFile$^{(R)}$, Hero Shaper$^{(R)}$, K3$^{TM}$. The electric motor set at a speed of 300 rpm and torque of 30 in a 16 : 1 reduction handpiece was used. The simulated root canal was prepared to ISO #25 sizes with each file system. The scanned images of pre- and post-instrumented canal of resin block were superimposed. To evaluate the screw-in effect of three NiTi file systems, apical terminus width of root canal was measured from superimposed images and statistical analysis was performed. There were significant differences in three NiTi flle systems. ProFile$^{(R)}$ had significantly smaller width than Hero Shaper$^{(R)}$ and K3$^{TM}$"" (P < 0.05), but no significant difference was observed between K3$^{TM}$ and Hero Shaper$^{(R)}$. Under the condition of this study, active file system (Hero SHaper$^{(R)}$, K3$^{TM}$) with variable pitch and helical angle had more screw-in effect than passive file system (ProFile$^{(R)}$) with constant pitch and helical angle. It seems that the radial lands play more important role in reducing screw-in effect.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.2
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• pp.87-97
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• 2017

Paulownia species has long been recognized in Korean traditional culture and the values of the species have been researched in various focuses. However, studies on distribution and ecological characteristics of the species are still needed. This study aimed to identify distribution trends and ecological characteristics of two Paulownia species in Busan metropolitan city using the MaxEnt model. The MaxEnt model was established based on the environmental factors such as positioning information of the Paulownia species, topography, climate and degree of anthropogenic disturbance potentiality (ADP), which was collected in the on-site research. The study verified that the accuracy of the model was appropriate as the AUC value of Paulownia coreana and P. tomentosa was 0.809, respectively. In terms of the distribution trends of the two Paulownia species in the research area depending on the distribution model, they were both mainly distributed in downtown where built-up area and bare ground were densely concentrated. The potential distribution area of the two species was identified as $137.4km^2$ for P. coreana and $135.0km^2$ for P. tomentosa. The distribution probability was high in Jung-gu, Dongrae-gu, Busanjin-gu and Yeonje-gu. As a result of the analysis on contribution of the environmental factors, it was turned out that the degree of anthropogenic disturbance potentiality (ADP) contributed to distribution of P. coreana and P. tomentosa by about 50%, and the contribution of the environmental factors had a positive correlation with the degree of ADP. The elevation had a negative correlation with both the two species, which was considered because the species must compete more with native species in natural habitats as the altitude above sea level rises. The research findings demonstrated numerically that the distribution of P.coreana and P. tomentosa depended on artificial activities, and indicated the relevance with the Korean traditional landscape. These findings are expected to provide meaningful information in using, preserving and restoring Paulownia species.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.537-545
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• 1995

Quality changes of lettuce were studied during storage to investigate the efficiency, cooling properties and the washing and storage effects of immersion-type hydrocooling. As a result of plotting the nondimensionalized lettuce temperature versus cooling time, its cooling rate coefficient was shown to be $-0.365\;min^{-1}{\sim}-0.255\;min^{-1}\;(R^2=0.99{\sim}0.88)$. Rate of weight loss was not significantly (p>0.05) different between lettuces with various treatment conditions during storage at $5^{\circ}C$. However, during storage at $15^{\circ}C$, weight loss of hydrocooled lettuce was lower than that of non-treated lettuce after from 10 to 15 days. Especially, The lettuce packed with PE was more effective than that packed with try in terms of packing condition after hydrocooling. Lettuce pretreated with sterilizing agent, packed with PE vinyl film, removed residual water after hydrocooling had lower decaying rate than any other lettuces. Changes of L and b values in hydrocooled lettuce were slower than those of non-treated one. During changes of chlorophyll content, the initial value, $115.7{\sim}147.3\;mg%$ was decreased to $50{\sim}60%$ after 25 days of storage at $5^{\circ}C$ and within 15 days of storage at $15^{\circ}C$. It could be presumed that the addition of sterilizing agent reduced the initial level of overall total and coliform count and its growth rate during storage. The respiration rate of hydrocooled lettuce at $5^{\circ}C$ was $23.95\;mg{\cdot}CO_2/kg\;hr$, which is 10% of those of non-treated lettuce.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.1
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• pp.109-116
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• 2008

In this study, the breads with medicinal herbs (MH) composites showing immunostimulating activity were prepared and their characteristics were examined. Fourteen kinds of medicinal herbs were extracted with hot water and divided into 3 groups (MH-1, MH-2, MH-3) based on their contents. All groups showed immunostimulating activity in terms of macrophage phagocytosis, nitrite production, cytostatic activity and cytokine production. In the preparation of breads containing MH extracts of various contents (0, 30, 50, 70, and 100%), there was no significant difference among dough pHs of all groups after first fermentation, but loaf volume was significantly (p<0.05) increased in 70% added group while decreased in 30%, 50%, and 100% added groups compared to the control. The "a" and "b" values of bread crumb increased with the content of MH extracts while "L" value decreased, but these values of bread crust were similar to the control group. Most improvements in hardness, adhesiveness, gumminess and chewiness of bread were noticed by the addition of 70% MH extracts, but those of springiness, cohesiveness and resilience were mostly by the 50% addition ones. Through the sensory evaluation, it was revealed that mouth feeling, taste and overall preference decreased at breads containing 70% and 100% extracts, although appearance and crumb texture were not significantly (p<0.05) different among all groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.668-672
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• 2001

To investigate the oxygen free radical and alcohol metabolizing system in liver of rats fed diets with 30% ethanol extract of Lycium chinense (LCEE), Sprague-Dawley male rats weighing 225~235g have been fed a diet supplemented with 2% or 4% LCEE for a month. The rats fed LCEE supplemented diets gained less body weight compared with the control, and had no remarkable changes of liver function. In rats fed 2% LCEE supplemented diet, hepatic cytochrome P450 contents appeared to be increased, but catalase (204.88$\pm$20.06 $H_2O$$_2$nmoles/mg protein/min), and superoxide dismutase (13.18$\pm$0.74 Unit/mg protein) activities were significantly increased compared with control 120.28$\pm$26.99 $H_2O$$_2$nmoles/mg protein/min and 10.49$\pm$0.80 Units/mg protein). There was no difference in hepatic glutathione content, glutathione peroxidase, and glutathione-S-transferase ctivities between the rats fed LCEE suplemented diets and the control diet. On the other hand, hepatic alcohol dehydrogenase activity were not changed by LCEE feeding, but hepatic aldehyde dehydrogenase activities were significantly increased in rats fed both 2 and 4% LCEE diets(5.01$\pm$0.21 and 4.47$\pm$0.06 $\mu$moles NADPH/mg protein/min) compared with control (3.28$\pm$0.21 $\mu$moles NADPH/mg protein/min) and its Vmax value was 1.9 fold increased in rats fed 2% LCEE and 1.5 fold in those fed 4% LCEE compared with control. In conclusion, it is likely that rats receiving a diet supplemented with LCEE may have the oxygen free radicals and alcohol detoxication potential.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.619-625
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• 2005

This study has been carried out to examine the characteristics of anti-H. pylori antibodies of milk produced from cows immunized with antigen of Helicobacter pylori such as peculiarity of antigen antibody, agglutination of H. pylori strain, stability of antibody against acid, alkali and heat treatments. The molecular weight of anti-H. pylori antibody measured by SDS-PAGE were turned out as about 50 kDa in the heavy chain and about 24 kDa in the light chain. Twenty protein bands were visualized in H. pylori interacting with anti-H. pylori antibody which was made in dairy cow by immunization with H. pylori. The western blotting was peformed in order to examine the antigen peculiarity of anti-H. pylori, The results were all 7 antigen substances including serum, furified serum, whey and furified whey could be confirmed and the major antigen substances were 97, 66,34 kDa of molecular weight. As a result of agglutination response anti-H. pylori antibody in whey showed 1/10 agglutination value against H. pylori. In stability test about acid and alkali of antibody, there was $100\%$ activated at the range of $pH5\~pH10$. In stability test about heat, the antibody showed stable condition at $60^{\circ}C$ for 60 minutes and comparatively stable condition at $70^{\circ}C$, but reduced activation to $40\%$ after 60 minutes. It maintained $77\%$ activation at $80^{\circ}C$ for 4 minutes and comparatively stable at $100^{\circ}C$ for 1 minute.