• Korean Journal of Ecology and Environment
• /
• v.46 no.4
• /
• pp.499-506
• /
• 2013

To estimate the effect of algae to particulate organic matter in the upper regions of brackish Lake Sihwa, temporal and spatial variations of particulate organic carbon (POC) and phytoplankton pigments (chlorophyll a; Chl-a, pheophytin-a; Pheo-a), and their relationships were studied at seven sites of the brackish regions from March to October 2005 and 2006. POC concentration varied from 1.0 to $76.6mgL^{-1}$ (mean $7.4mgL^{-1}$), with maximal concentrations occurring in the middle parts of the study area in spring of 2005 and 2006. Concentrations of Chl-a and Pheo-a varied from 1.3 to $942.9{\mu}gL^{-1}$ (mean $71.0{\mu}gL^{-1}$) and $1.4{\sim}1,545.5{\mu}gL^{-1}$ (mean $59.9{\mu}gL^{-1}$), respectively, and corresponded closely with variation in POC. During the study period Pheo-a concentration was 44.2% of total Chl-a, implying that non-living or inactive phytoplankton is also the important part of phytoplankton-derived POC in brackish regions of Lake Sihwa. From the positive linear relationships between POC and phytoplankton pigments (POC with Chl-a (r=0.93), total Chl-a (r=0.88), and Pheo-a (r=0.81)), it is suggested that phytoplankton was a significant component of POC in the upper regions of brackish Lake Sihwa. On the other hand, the ratios of POC/Chl-a and POC/total Chl-a (Chl-a+Pheo-a) were 82.9 and 35.9, respectively. The ratio of POC/total Chl-a is similar to those reported in previous studies, including 40~60 in estuaries. This study suggests that Pheo-a concentration is considered in estimation of POC concentration from phytoplankton pigments in aquatic systems with high content of Pheo-a, like an upper region of blackish Lake Sihwa.

• Journal of Korean Society of Forest Science
• /
• v.81 no.1
• /
• pp.1-10
• /
• 1992

This study was conducted to explain the characters of the structure of biomass production in the thrifty-mature Quercus mongolica stands and investigate the relationships between the leaf weight or leaf area and the sapwood area in the bole. Also we intended to identify the allocation ratio of stem, branches, and leaves or heartwood, sapwood and bark in trees and the characters of productive structure of stem and leaf biomass by the tree height. The results obtained were as follows : 1. The allocation ratio of biomass based on dry weight was 70-84% in stem, 11-25% in branches, and 3-6% in leaves. 2. In the bole, the ratios of composition of heartwood, sapwood, and bark were showed 37-43%, 38-46%, and 16-19%, respectively. 3. The volume of sapmood was exceeded more than that of heartwood in dominant and intermediate trees, while it was reversely appeared in suppressed trees. 4. The weight and area of leases significantly correlated with the sectional area of sapwood in bole (r>0.9. 1% significant level). 5. The ratio of leaf area($m^2$) to sapwood areal($cm^2$), k varied 0.35 to 2.05. 6. The basal diameter and the cross sectional area of a branch significantly correlated with the leaf weight r>0.9. 1% significant level. 7. The leaf weight in a tree is showed a normal distribution curve and the accumulative volume of bole is showed a tapering type.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.11
• /
• pp.1443-1451
• /
• 2008

This study was performed to develop menu satisfaction index in Business & Industry (B&I) food service and to survey customer's menu satisfaction using the index. The menu satisfaction index included 16 items with Likert 5 point. Cronbach's alpha to assess the internal reliability of the developed scales was 0.8917, which indicated highly reliable. Construct validity was assessed by principal components analysis and then four factors explaining 65.964% of the total variance were found. Among the 15 items of menu satisfaction, the average scores of all items were above 3.0 out of 5. As a result of analysis on menu satisfaction factors, 'propriety of food temperature' (3.52 out of 5) was the highest consideration followed by 'sufficiency of format' (3.46), 'excellence in food' (3.35) and 'well-being orientation' (3.31). It could be said that customer's perception on the menu quality was very positive. Four factors were correlated with overall menu satisfaction positively. Especially, 'excellence in food', and 'well-being orientation' and 'sufficiency of format' affected significantly on overall menu satisfaction. It concluded that customers were satisfied with portion size, temperature, price but their needs for taste and health/nutrition-related service would be increased. The menu satisfaction developed in this study should be applied to other B & I food service operation by type.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.12 no.3
• /
• pp.65-79
• /
• 1992

This study is concerned with the optimal design of two hinged steel arches with I cross sectional type and aimed at the exact analysis of the arches and the safe and economic design of structure. The analyzing method of arches which introduces the finite difference method considering the displacements of structure in analyzing process is used to eliminate the error of analysis and to determine the sectional force of structure. The optimizing problems of arches formulate with the objective functions and the constraints which take the sectional dimensions(B, D, $t_f$, $t_w$) as the design variables. The object functions are formulated as the total weight of arch and the constraints are derived by using the criteria with respect to the working stress, the minimum dimension of flange and web based on the part of steel bridge in the Korea standard code of road bridge and including the economic depth constraint of the I sectional type, the upper limit dimension of the depth of web and the lower limit dimension of the breadth of flange. The SUMT method using the modified Newton Raphson direction method is introduced to solve the formulated nonlinear programming problems which developed in this study and tested out throught the numerical examples. The developed optimal design programming of arch is tested out and examined throught the numerical examples for the various arches. And their results are compared and analyzed to examine the possibility of optimization, the applicablity, the convergency of this algorithm and with the results of numerical examples using the reference(30). The correlative equations between the optimal sectional areas and inertia moments are introduced from the various numerical optimal design results in this study.

• Korean Journal of Environmental Agriculture
• /
• v.36 no.2
• /
• pp.119-128
• /
• 2017

BACKGROUND: Miscellaneous cereal have been largely consumed in Korea as due to their physiological functions beneficial to human health. The cereals are currently a social concern because they have been found to contain heavy metals. Thus, monitoring heavy metals in the cereals is an important requirement for food safety analysis. In this study, we determined arsenic concentration in the cereals randomly harvested from different markets. METHODS AND RESULTS: Inorganic arsenic was determined by ICP-MS coupled with HPLC system. The HPLC-ICP-MS analysis was optimized based on the limit of detection and recover test to reach $0.13-1.24{\mu}g/kg$ and 94.3-102.1%, respectively. The concentrations of inorganic arsenic equivalent to daily exposure were levels of $19.91{\mu}g/day$ in mixed grain, $1.07{\mu}g/day$ in glutinous rice, $0.77{\mu}g/day$ in black brown rice, $0.13{\mu}g/day$ in barley and $0.11{\mu}g/day$ in soybeans. CONCLUSION: The levels of arsenic in miscellaneous cereals were found lower than the recommended The Joint FAO/WHO Expert Committee on Food Additives (JECFA) levels, suggesting that the cereals marketed in Korea are not potential concern in risk assessment.

• Journal of Animal Science and Technology
• /
• v.51 no.4
• /
• pp.265-272
• /
• 2009

A total of 486 milk records were collected from 16 diary farms in Imsil-gun, Jeollabuk-do. Results obtained were as follows: The average 3MG (amount of milk within the first three minute) was 7.44 kg and 55% of total milk yield was produced within 3 min. The average of SPL (% of foam in milk) was 33.93% and the average of MNG (strip yield) was 0.14 kg, which was less than 1% of total milk yield. The averages of HMF (highest milk flow), HMG (maximum milk flow rate in one minute) and DMHG (average milk flow in the main milking phase) were 3.03 kg/min, 2.94 kg/min and 2.05 kg/min, respectively and the average milking speed in Imsil-gun was slower than other regions. The average of tS500(time to reach 0.5 kg/min at beginning) was 0.23min (about 14 seconds) and that of tMGG (duration of the total milking) was 7.75min. The average tMBG (duration of the dry milking phase) was 0.58 min (35 seconds) and that of tMNG (duration of the stripping phase) was 0.42min (14 seconds). The averages of ELHMF (electrical conductivity at highest milk flow) and ELAP (beginning peak level of the electrical conductivity) were 6.81 mS/cm and 7.58 mS/cm, respectively. The average of ELMAX (maximum electrical conductivity) was 7.48 mS/cm and that of ELAD (beginning peak difference of the electrical conductivity) was 0.61 mS/cm. While the total milk yields for DMHG, tMHG (duration of the main milking phase), tPL (duration of the plateau phase), tAB (duration of the descending phase) and tMGG were positively correlated (0.35~0.54), those for tMBG and SPL were negatively correlated (-0.11 and -0.27). As the DMHG increased, tMHG, tPL, tAB, tMGG and SPL decreased. While the cows with higher electrical conductivity at the beginning of milking had less somatic cell counts, cows with higher electrical conductivity after the peak of milk yield had more somatic cell counts. The results of this experiment indicated that through milking based on milking and lactating standards and the regular checking of milking status, the qualities of milk and milk yields could be improved.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.8
• /
• pp.1175-1181
• /
• 2005

The purpose of this study was to investigate the effects of green vegetable (kale) juice powder supple-mentation on lipid profiles, plasma homocysteine, folate and vitamin $B_{12}$ in rats fed cholesterol (Chol. ) or Chol. free diet. 7-week old male Sprague Dawley rats (n=40) were divided into 4 groups, and experimental diets containing control diet group (CO), control diet plus 0.5 wt$ \% $ Chol. (CC), control diet added with 5 wt$ \% $ kale (KO), control diet added with 5 wt$ \% $ kale plus 0.5 wt$ \% $ Chol. (KC) were fed for 8 wks. Plasma homocysteine level was examined by amino acid analyzer and serum folate and vitamin $B_{12}$ level were measured by com-petitive radioimmunoassay methods. In various serum lipid profiles, TG level was lower in kale juice powder groups (KO, KC) compared to the corresponding groups (CO, CC) (p<0.001). In Chol. supplemented groups (CC, KC), HDL-Chol. level was lower (p<0.001) and LDL-Chol. level was higher (p<0.05) than Chol. free diet. HDL-Chol. level was higer (p<0.05) in kale juice powder groups. HDL/LDL ratio was lower in Chol. supplemented groups (CC, KC) and tended to be higher in kale juice powder groups (KO, KC) Serum folate and vitamin $B_{12}$ levels were not affected by dietary Chol. and kale juice powder supplementation. Plasma homocysteine level was not affected by dietary Chol. and kale juice powder supplementation, too. Serum folate level was positively correlated with serum vitamin $B_{12}$ level (r=0.5632, p<0.001), but plasma homocysteine level was not significantly correlated with any serum folate, vitamin $B_{12}$ and Chol. levels, respectively. In summary, kale juice powder supplementation have improved serum lipid profiles by increasing the HDL level and decreasing the TG level and have not altered homocysteine level under the sufficient supply of folate and vitamin B complex relating with the homocysteine metabolism.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.37 no.3
• /
• pp.257-264
• /
• 2011

In this study, to evaluate the antioxidative activities and anti-inflammatory effects of kaempferol and its rhamnosides, we performed the free radical scavenging assay, ROS inhibition assay and TARC (thymus and activation-regulated chemokine) assay. Also, we studied physiological activity of kaempferol and its rhamnosides (${\alpha}$-rhamnoisorobin, afzelin, kaempferitn) by structure-activity relations. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities were determined with kaempferol (62.5 ${\mu}M$) and ${\alpha}$-rhamnoisorobin (50.0 ${\mu}M$) but afzelin and kaempferitrin did not show free radical scavenging activities. Kaempferol showed a 97.5, 57.8, 47.8 % inhibition of ROS (reactive oxygen species) generated at concentrations of 10, 50 and 100 ${\mu}M$, compared to control (100 %). ${\alpha}$-rhamnoisorobin showed a 93.1, 59.1 and 41.4 % inhibition of ROS at the same concentration. We investigated the inhibitory effects of kaempferol and its rhamnosides on TARC expression. Kaempferol showed a 48.8, 5.5 and 4.4 % inhibition of TARC generated at 10, 50 and 100 ${\mu}M$, compared to control. ${\alpha}$-Rhamnoisorobin showed a 88.1, 19.0 and 1.0 % inhibition of TARC generated at the same concentration. In conclusion, these results indicate that kaempferol and ${\alpha}$-rhamnoisorobin have good antioxidative activities and anti-inflammatory effects that could be applicable to new functional cosmetics for anti-aging and anti-inflammation.

• Korean Chemical Engineering Research
• /
• v.48 no.2
• /
• pp.259-267
• /
• 2010

The catalytic wet oxidations of the wastewater containing azo dye Reactive Black 5(RB5) with heterogeneous catalyst of CuO have been carried out to investigate the effects of temperature($190{\sim}230^{\circ}C$) and catalyst concentration(0.00~0.20 g/l) on the removals of colour and total organic carbon TOC. The wastewater colour was measured with spectrophotometer, and the oxidation rate was estimated with TOC. About 90% of colour was removed during 120 min in thermal degradation of the RB5 wastewater at $230^{\circ}C$, while TOC was not removed at all. As increasing reaction temperature and catalyst concentration, the removal rates of colour and TOC increased in the catalytic wet oxidations of RB5 wastewater. The effects of catalyst were already considerable even at 0.01 g CuO/l, while the removal rates of colour and TOC increased negligibly with increasing the catalyst concentration above 0.05 g CuO/l. The initial destruction rates of the wastewater colour have shown the first-order kinetics with respect to the wastewater colour. TOC changes during catalytic wet oxidations have been well described with the global model, in which the easily degradable TOC was distinguished from non-degradable TOC of the wastewater. The impacts of reaction temperature on the destruction rate of the wastewater colour and TOC could be described with Arrhenius relationship. Activation energies of the colour removal reaction in thermal degradation, wet oxidation, and catalytic wet oxidation(0.20 g CuO/l) of the RB5 wastewater were 108.4, 78.3 and 74.1 kJ/mol, respectively. The selectivity of wastewater TOC into the non-degradable intermediates relative to the end products in the catalytic wet oxidations of RB5 wastewater was higher compared to that in phenol wet oxidations.

• Korean Journal of Environmental Agriculture
• /
• v.6 no.2
• /
• pp.53-65
• /
• 1987

The study was performed to investigate the effect of gaseous emissions of sulfur dioxide and hydrogen fluoride on the growth of rice plants under stressed field conditions consisting of 88 industrial plants operating with 285 smoke stacks emitting pollutants. As for the relationship between yields and yield components it is believed that the panicles per hill is the single most important component affecting the rate of yield of the rice plant. Based on the standard partial regression coefficient analysis, panicles per hill has the largest contribution to yield and the average contribution of 54%. Other components such as spikelets per panicle, percent fertility and 1000 grain weight are also contributing factors to yield, although far less so. Fluorine content in the leaf appear to have more negative effect on panicles per hill, percent fertility and subsequent overall yield than does sulfur content in the leaf. It is constantly observed and interesting to note that fluorine and sulfur content in the leaf appears to have no effect on spikelets per panicle and 1000 grain weight. Reduction in yield seems to be affected mainly by panicles per hill which are, in turn, affected more by fluorine content in the leaf as demonstrated by the standard partial coefficient analysis. Regarding the prediction sum of the square of the regression equation, the lowest value was found when nine variables were used for the analysis. The variables taken into consideration were the monthly sulfur and fluorine content in the leaf as well as the monthly percent of leaf damage during the months of June, July and August. A significant correlation is found between the actual and predicted yields by the regression equations selected as a result of a prediction sum of the square analysis.