• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.3
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• pp.228-239
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• 1995

A model experiment on the pair midwater trawl net which is prevailing in Denmark is carried out to get the basic data available for Korean pair bottom trawlers. The model net was made in 1/30 scale considering the Tauti's Similarity law of fishing gear and the dimension of experimental tank. The vertical opening, horizontal opening, towing tension and net working depth of the model net were determined in the tank within the towing velocity 0.46~1.15m/sec, front weight 15.5~62.0g and distance between paired boats 5~8m(which correpond to 2~5k't in towing velocity, 70~280kg in weight and 150~240m in distance respectively in the prototype net). The results got from the model experiment can be converted into the full scale net as follows; 1. Vertical opening showed the largest value of 32m at the condition of 2k't in towing velocity, 280kg in front weight and 150m in the distance between paired boats, and the smallest value of 6m at the condition of 5k't in towing velocity, 70kg in front weight and 240m in the distance between paired boats. 2. Horizontal opening showed the largest value of 45m at the condition of 5k't in towing velocity, 70kg in front weight and 240m in the distance between paired boats, and the smallest value of 33m at the condition of 2k't in towing velocity, 280kg in front weight and 150m in the distance between paired boats. 3. Towing tension showed the largest value of 10, 000kg at the condition of 5k't in towing velocity, 280kg in front weight and 240m in the distance between paired boats, and the smallest value of 1, 600kg at the condition of 2k't in towing velocity, 70kg in front weight and 150m in the distance between paired boats. 4. Net working depth showed the largest value of 38m at the condition of 2k't in towing velocity, 280kg in front weight and 150m in the distance between paired boats, and the smallest value of 6m at the condition of 5k't in towing velocity, 70kg in front weight and 240m in the distance between paired boats. 5. Net opening area showed the largest value of 1, 100m super(2) at the condition of 2k't in towing velocity, 280kg in front weight and 180m in the distance between paired boats, and the smallest value of 250m super(2) at the condition of 5k't in towing velocity, 70kg in front weight and 240m in the distance between paired boats.

• The Korean Journal of Food And Nutrition
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• v.24 no.1
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• pp.138-143
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• 2011

This study analyzed the maltol quality, composition ratio of fatty acids, and contents of phenolic compounds in white ginseng extracts(four types), red ginseng extracts(five types), black ginseng extracts(two types), and Chinese ginseng extracts(nine types). By examining patterns in these measurements, we determined the characteristic factors of the extracts and measured the possibility of qualitative analysis. In the analysis of maltol using TLC, white ginseng extracts were not detected while red and black ginseng extracts were detected, so the possibility of detection was considered as a characteristic factor for qualitative analysis. Regarding the composition of fatty acids, palmitic and linoleic acids were the main fatty acids in the ginseng extracts palmitic acid was high in white ginseng extracts while linoleic was low in red ginseng extracts. Regarding the ratio(Pal/Lin) of the two fatty acids, there was a large difference between white ginseng extracts(56.7~64.3%) and red ginseng extracts(32.0~38.5%), and these figures seemed to be characteristic factors for the analysis. For the phenolic compounds, extracts contained maltol, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and cinnamic acid. White ginseng extracts contained similar percentages of phenolic compounds while red ginseng extracts had high maltol content. According to the measurement results of the percentages of maltol and cinnamic acid, white ginseng extracts showed values below five, whereas red and black ginseng extracts showed 53~289, which was also a characteristic factor for qualitative analysis. Consequently, we found that we can differentiate between ginseng extracts using characteristic factors that we analyzed in an experiment on white ginseng extracts from China.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.387-391
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• 2007

This study was conducted to evaluate effects of dietary nutrient levels on growth performance, blood urea nitrogen, and meat quality in finishing pigs. A total of ninety six pigs ($Landrace{\times}Yorkshire{\times}Duroc$) were used in this 66 day study. Dietary treatments included 1) T1 (ME 3,441 kcal/kg, CP 16.30%, Lysine 0.93%), 2) T2 (ME 3,433 kcal/kg, CP 17.00%, Lysine 1.00% and 3) T3 (ME 3,449 kcal/kg, CP 17.00%, Lysine 1.00%). During the overall period, there were no significant differences in ADG (average daily gain), ADFI (average daily feed intake), gain/feed ratio or BUN (blood urea nitrogen) among the treatments (p>0.05). The $b^*$ value of M. longissimus dorsi muscle color significantly increased (p<0.05) with T3 treatment compared to T2 treatment. However, there were no differences in the $L^*\;and\;a^*$ values, pH, M. logissimus dorsi area, drip loss, cooking loss, TBARS and WHC (water holding capacity) for pigs fed the various treatments (p>0.05). The total feed cost per kg of weight gain was not significantly different among the various dietary treatments (p>0.05). In conclusion, these results show no effects of dietary nutrient levels on growth performance and meat quality in finishing pigs, and also suggest that a high nutrient density diet may not be a beneficial feeding strategy for finishing pigs in terms of cost.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.619-625
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• 2001

We determined whether the supplementation of Polygonatum Odoratum (Mill) Druce (POD) extract had a good effect on insulin resistance in peripheral tissues of 90% pancreatectomized (Px) and sham-operated (Sham) male Sprague Dawley rats. Px and Sham rats were divided into two groups; one group daily consumed 0.3 g of POD extracts per 1 ㎏ body weight for two months, and the other group had a placebo. All rats freely consumed a 40% fat diet. At the end of the experiment, a euglycemic hyperinsulinemic (EH) clamp was performed in a fasting, awake, and unstressed state to determine insulin resistance. At EH clamp, body weights were higher in Sham rats than Px rats, and serum glucose levels of baseline were affected by diabetic status and POD administration. Serum insulin concentrations were higher in Sham rats than Px rats, and POD administration decreased them in Sham rats compared to P. Glucose disposal rates in peripheral tissues increased with POD in both Px (n=10) and Sham (n=10) rats. But glycogen deposits in soleus muscle increased with POD administration in Px and Sham rats, and total glycogen synthase activity and fraction velocity were higher in POD groups. Triglyceride contents in quadriceps muscles decreased with POD in Px rats. In conclusions, POD improves insulin resistance by enhancing glucose utilization with increasing glycogen deposit and decreasing triglyceride contents in muscles.

• Journal of Nutrition and Health
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• v.52 no.6
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• pp.515-528
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• 2019

Purpose: This study examined the immunological activity and optimized the mixture conditions of Sargassum horneri (S. horneri) extracts in vitro and in vivo models. Methods: S. horneri was extracted using three different methods: hot water extraction (HWE), 50% ethanol extraction (EE), and supercritical fluid extraction (SFE). Splenocyte proliferation and cytokine production (Interleukin-2 and Interferon-γ) were measured using a WST-1 assay and enzyme-linked immunosorbent assay, respectively. The levels of nitric oxide and T cell activation production were measured using a Griess assay and flow cytometry, respectively. The natural killer (NK) cell activity was determined using an EZ-LDH kit. Results: Among the three different types of extracts, HWE showed the highest levels of splenocyte proliferation and cytokine production in vitro. In the animal model, three different types of extracts were administrated for 14 days (once/day) at 50 and 100 mg/kg body weight. HWE and SFE showed a high level of splenocyte proliferation and cytokine production in the with and without mitogen-treated groups, whereas EE administration did not induce the splenocyte activation. When RAW264.7 macrophage cells were treated with different mixtures (HWE with 5, 10, 15, 20% of SFE) to determine the optimal mixture ratio of HWE and SFE, the levels of nitric oxide and cytokine production increased strongly in the HWE with 5% and 10% of SFE containing group. In the animal model, HWE with 5% and 10% of SFE mixture administration increased the levels of splenocyte proliferation, cytokine production, and activated CD4⁺ cell population significantly, with the highest level observed in the HWE with 5% of SFE group. Moreover, the NK cell activity was increased significantly in the HWE with 5% of SFE mixture-treated group compared to the control group. Conclusion: The optimal mixture condition of S. horneri with immune-enhancing activity is the HWE with 5% of SFE mixture. These results confirmed that the extracts of S. horneri and its mixtures are potential candidate materials for immune enhancement.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.77-83
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• 2016

The measurement of total fresh weight of plants provides an essential indicator of crop growth for monitoring production. To measure fresh weight without damaging the vegetation, image-based methods have been developed, but they have limitations. In addition, the total plant fresh weight is difficult to measure directly in hydroponic cultivation systems because of the amount of nutrient solution. This study aimed to develop a real-time, precise method to measure the total fresh weight of Romaine lettuce (Lactuca sativa L. cv. Asia Heuk Romaine) with growth stage in a plant factory using a nutrient film technique. The total weight of the channel, amount of residual nutrient solution in the channel, and fresh shoot and root weights of the plants were measured every 7 days after transplanting. The initial weight of the channel during nutrient solution supply (Wi) and its weight change per second just after the nutrient solution supply stopped were also measured. When no more draining occurred, the final weight of the channel (Ws) and the amount of residual nutrient solution in the channel were measured. The time constant (${\tau}$) was calculated by considering the transient values of Wi and Ws. The relationship of Wi, Ws, ${\tau}$, and fresh weight was quantitatively analyzed. After the nutrient solution supply stopped, the change in the channel weight exponentially decreased. The nutrient solution in the channel slowly drained as the root weight in the channel increased. Large differences were observed between the actual fresh weight of the plant and the predicted value because the channel included residual nutrient solution. These differences were difficult to predict with growth stage but a model with the time constant showed the highest accuracy. The real-time fresh weight could be calculated from Wi, Ws, and ${\tau}$ with growth stage.

• Restorative Dentistry and Endodontics
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• v.30 no.1
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• pp.58-65
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• 2005

The purpose of this study was to compare the shaping ability of the three $ProTaper^{(R)}$ instrumentation techniques in simulated canals. Thirty resin blocks were divided into 3 groups with 10 canals each. Each group was instrumented with manual $ProTaper^{(R)}$ (Group M), rotary $ProTaper^{(R)}$ (Group R), and hybrid technique (Group H). Canal preparation time was recorded. The images of pre- and post-instrumented root canals were scanned and superimposed. The amounts of canal deviation, total canal width, inner canal width, outer canal width and centering ratio were measured at apical 1, 2, 3, 4, 5 and 6 mm levels 1. Canal preparation time was the shortest in R group (p < 0.05). 2. The amounts of total canal width in R group was generally larger than the other groups, but no significant differences were observed except at the 1, 3 mm levels (p > 0.05) .3. The amounts of inner canal width in R group was larger than M group at the 1 mm level and H group was larger than R group at the 6 mm level (p < 0.05). The amounts of outer canal width in R group was larger than H group only at the 1 mm level (p < 0.05). 4. The direction of canal deviation in H, R group at the 1, 2, 3 mm levels was outward and that in M group at the 1, 2 mm levels was inward. The amounts of canal deviation in H group was larger than R group at the 6 mm level (p < 0.05). 5. The amounts of centering ratio in H group was larger than R group at the 6 mm level (p < 0.05).

• Restorative Dentistry and Endodontics
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• v.30 no.6
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• pp.450-460
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• 2005

The aim of this study was to evaluate the effect of cavity shape, bond quality of bonding agent and volume of resin composite on shrinkage stress developed at the cavity floor. This was done by measuring the shear bond strength with respect to iris materials (cavity shape , adhesive-coated dentin as a high C-factor and Teflon-coated metal as a low C-factor), bonding agents (bond quality: $Scotchbond^{TM}$ Multi-purpose and Xeno III) and iris hole diameters (volume; 1mm or 3mm in $diameter{\times}1.5mm$ in thickness). Ninety-six molars were randomly divided into 8 groups ($2{\times}2{\times}2$ experimental setup). In order to simulate a Class I cavity, shear bond strength was measured on the flat occlusal dentin surface with irises. The iris hole was filled with Z250 restorative resin composite in a bulk-filling manner. The data was analyzed using three-way ANOVA and the Tukey test. Fracture mode analysis was also done When the cavity had high C-factor, good bond quality and large volume, the bond strength decreased significantly The volume of resin composite restricted within the well-bonded cavity walls is also be suggested to be included in the concept of C-factor, as well as the cavity shape and bond quality. Since the bond quality and volume can exaggerate the effect of cavity shape on the shrinkage stress developed at the resin-dentin bond, resin composites must be filled in a method, which minimizes the volume that can increase the C-factor.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.356-363
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• 2009

The purpose of this study was to evaluate the viability of periodontal ligament cells in rat teeth using slow cryo-preservation method under pressure by means of MTT assay and WST-1 assay. Eighteen teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both sides of the first and second maxillary molars were extracted as atraumatically as possible under Tiletamine anesthesia. The experimental groups were group 1 (Immediate control), group 2 (Cold preservation at $4^{\circ}C$for 1 week), group 3 (Slow freezing), group 4 (Slow freezing under pressure of 3 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in $37^{\circ}C$water bath, then MTT assay and WST-1 assay were processed. One way ANOVA and Tukey method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 4 showed significantly higher viability of periodontal ligament cells than group 2 and 3 (p < 0.05), but showed lower viability than immediate control group. By the results of this study, slow cryo-preservation method under pressure suggests the possibility for long term cryo-preservation of the teeth.

• Current Research on Agriculture and Life Sciences
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• v.30 no.2
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• pp.68-75
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• 2012

This study was conducted to monitor the yields of useful substances extracted from Inonotus obliquus. Optimization of ultrasonic-assisted extraction process was carried out by using response surface methodology under different extraction conditions. A central composite design was applied to investigate the effects of independent variables such as extraction time ($X_1$), ethanol concentration ($X_2$) and extraction temperature ($X_3$) on dependent variables such as soluble solid yield ($Y_1$), total phenol contents ($Y_2$), total flavonoid contents ($Y_3$) and browning color($Y_4$). Soluble solid yield was affected by ethanol concentration and extraction temperature. The maximum soluble solid yield was 18.02% at 20.47 min ($X_1$), 42.85% ($X_2$) and $69.57^{\circ}C$ ($X_3$) in saddle point. Total phenol contents were highly affected by ethanol concentration and extraction temperature. The maximum total phenol contents were 71.57mg GAE/g at 21.60min ($X_1$), 45.19% ($X_2$), $69.68^{\circ}C$ ($X_3$). The electron donating ability was affected by extraction temperature and extraction time. Total flavonoid contents were affected by only extraction temperature. The maximum total flavonoid contents were 35.98 mg RE/g at 22.53min ($X_1$), 46.37% ($X_2$), $69.56^{\circ}C$ ($X_3$) in saddle point. The browning color was highly affected by extraction time, ethanol concentration and extraction temperature. The maximum browning color was at 22.00 min ($X_1$), 46.89% ($X_2$), $69.71^{\circ}C$ ($X_3$) in saddle point. As a result, the optimum extraction conditions were predicted; extraction time of 21.50 min, ethanol concentration of 44.87% and extraction temperature of $69.635^{\circ}C$.