• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.8
• /
• pp.449-455
• /
• 2019

The increase in impermeable pavement from recent urbanization has resulted in an increase in surface runoff. The surface runoff has also increased the burden of the existing drainage system. This drainage system has structural limitations in that the catchment area is reduced by the waste particles transported with the surface runoff. In addition, the efficiency of the drainage system is decreased. To overcome these limitations, a new type of drainage system with a drainage layer was developed and applied. In this study, various volume porosity and permeability of the lower drainage layer were simulated using ANSYS CFX, which is a three dimensional computational fluid dynamics program. The results showed that the outlet velocity of the 35% volume porosity was faster than that of the 20% and 50% cases, and there was no relationship between the volume porosity and drainage performance. The permeability of the drainage layer can be determined from the particle size of the material, and a simulation of five conditions showed that 2 mm sand grains are most suitable for workability and usability. This study suggests appropriate values of the volume porosity and particle size of the drainage layer. This consideration can be advantageous for reducing and preventing flood damage.

• Tuberculosis and Respiratory Diseases
• /
• v.45 no.4
• /
• pp.846-860
• /
• 1998

Background: Endotoxin (LPS : lipopolysaccharide), a potent activator of immune system, can induce acute and chronic inflammation through the production of cytokines by a variety of cells, such as monocytes, endothelial cells, lymphocytes, eosinophils, neutrophils and fibroblasts. LPS stimulate the mononucelar cells by two different pathway, the CD14 dependent and independent way, of which the former has been well documented, but not the latter. LPS binds to the LPS-binding protein (LBP), in serum, to make the LPS-LBP complex which interacts with CD14 molecules on the mononuclear cell surface in peripheral blood or is transported to the tissues. In case of high concentration of LPS, LPS can stimulate directly the macrophages without LBP. We investigated to detect the generation of proinflammatory cytokines such as interleukin 1 (IL-1), IL-6 and TNF-$\alpha$ and fibrogenic cytokine, TGF-$\beta$, by peripheral blood mononuclear cells (PBMC) after LPS stimulation under serum-free conditions, which lacks LBPs. Methods : PBMC were obtained by centrifugation on Ficoll Hypaque solution of peripheral venous bloods from healthy normal subjects, then stimulated in the presence of LPS (0.1 ${\mu}g/mL$ to 100 ${\mu}g/mL$ ). The activities of IL-1, IL-6, TNF, and TGF-$\beta$ were measured by bioassaies using cytokines - dependent proliferating or inhibiting cell lines. The cellular sources producing the cytokines was investigated by immunohistochemical stains and in situ hybridization. Results : PBMC started to produce IL-6, TNF-$\alpha$ and TGF-$\beta$ in 1 hr, 4 hrs and 8hrs, respectively, after LPS stimulation. The production of IL-6, TNF-$\alpha$ and TGF-$\beta$ continuously increased 96 hrs after stimulation of LPS. The amount of production was 19.8 ng/ml of IL-6 by $10^5$ PBMC, 4.1 ng/mL of TNF by $10^6$ PBMC and 34.4 pg/mL of TGF-$\beta$ by $2{\times}10^6$ PBMC. The immunoreactivity to IL-6, TNF-$\alpha$ and TGF-$\beta$ were detected on monocytes in LPS-stimulated PBMC. Some of lymphocytes showed positive immunoreactivity to TGF-$\beta$. Double immunohistochemical stain showed that IL-1$\beta$, IL-6, TNF-$\alpha$ expression was not associated with CD14 postivity on monocytes. IL-1$\beta$, IL-6, TNF-$\alpha$ and TGF-$\beta$mRNA expression were same as observed in immunoreactivity for each cytokines. Conclusion: When monocytes are stimulated with LPS under serum-free conditions, IL-6 and TNF-$\alpha$ are secreted in early stage of inflammation. In contrast, the secretion of TGF-$\beta$ arise in the late stages and that is maintained after 96 hrs. The main cells releasing IL-1$\beta$, IL-6, TNF-$\alpha$ and TGF-$\beta$ are monocytes, but also lymphocytes can secret TGF-$\beta$.

• Journal of Animal Science and Technology
• /
• v.52 no.4
• /
• pp.337-346
• /
• 2010

We report non-specific immune responses and disease resistance against Vibrio anguillarum, Streptococcus iniae and Edwardsiella tarda by dietary supplementation of fermented garlic powder (FGP) in olive flounder for the first time. Four isonitrogenous (45% crude protein) and isocaloric (17.1 MJ/kg) diets were formulated to have 0%, 0.5%, 1% and 2% of the FGP (G-0, G-0.5, G-1 and G-2). The experimental diets were fed to juvenile olive flounder averaging 23.4 g in triplicate groups (90 fish/group) in a flow-through system. After a five-week feeding trial, healthy fish with similar sizes from each tank were selected and injected with 1 ml of three bacteria each to evaluate disease resistance of the fish. During the 5-week feeding trial, the weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio, and survival of the fish were not significantly affected by the experimental diets. However, feed intake was significantly lower (P<0.05) in the fish fed the G-2 diet compared with the control group. Hemoglobin, myeloperoxidase activity, cholesterol and HDL-cholesterol were not different between the dietary groups. However, hematocrit, nitroblue tetrazolium (NBT) activity, and lysozyme activity were increased (P<0.05) with an increment of dietary FGP. Plasma triglyceride of the fish fed the G-0.5 diet was significantly lower than that of fish fed the control diet. The cumulative mortality was lower in the fish fed diets containing FGP compared with the control group in the challenge test except for the bacteria Edwardsiella tarda. The results in this study indicate that dietary supplementation of FGP can enhance the non-specific immune responses and disease resistance of olive flounder against V. anguillarum and S. iniae.

• Korean Journal of Environmental Agriculture
• /
• v.32 no.2
• /
• pp.166-170
• /
• 2013

BACKGROUND: Persimmon growers have often tried various regimens of K fertilization to improve fruit quality. This experiment was conducted to determine the effects of K rates on concentration of inorganic elements in different tree organs and on fruit characteristics. METHODS AND RESULTS: Six-year-old non-astringent 'Fuyu' persimmons, grown in 50-L pots, were used. Total K amounts of 0 (no-application), 12, 25, 37, and 66 g were fertigated to a pot with KCl solution at 3-to 4-day intervals from July to September. The 0 K trees received no K fertilizer for the two previous years. Leaves, fruits, and shoots were sampled in November. K concentrations in leaves and shoots increased significantly by increasing K rate; leaf K, 0.49% for the 0 K, increased to 3.09% for the 37 g and 3.11% for the 66 g trees. Fruit K was notably lower for the 0 K, but there were no significant differences among the trees as long as they were supplied with more than 12-g K. In the trees with 0 K, leaf necrosis in the margin was apparent in June and the symptom progressed toward the midrib. Some leaves scorch-rolled from the margin in August. The greatest effect of K rates was on fruit size; it significantly increased to 181 g for the 12 g, 203 g for the 37 g, and 206 g for the 66 g compared with 150 g for the 0 K trees. However, K rates did not affect firmness and soluble solids of the fruits. The fruits of the 0 K trees were characterized by better coloration. CONCLUSION(S): The K-rate effect on inorganic elements depended on tree organs and fruit size was the major parameter to be affected by the K rates.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.1
• /
• pp.53-57
• /
• 2013

A severe defoliation by typhoon in early autumn reduces fruit quality for the current season and reserve accumulations for the next season. This study was conducted to determine the effects of foliar applications during the autumn on alleviating the damages after defoliation. Leaves of 2-year-old 'Fuyu' trees, grown in 50-L pots under a rain-shelter, were 75%-defoliated on September 9. In mid-September and early October, trees were treated either with eight foliar applications of urea or with four alternating applications of urea and $KH_2PO_4$ (urea + KP application), all at 0.5% (w/v). Trees untreated after the defoliation served as the control. The urea applications slightly increased N and P concentrations of the leaves collected on November 6, while urea + KP applications significantly increased P and K concentrations. Foliar applications did not affect fruit growth, but tended to decrease skin coloration. Fruit soluble solids increased by 1.5 and $1.0^{\circ}Brix$ for urea and urea + KP applications, respectively. There was a significant increase in dry weight of fine root for the foliar application treatments but not in those of aerial woods and larger roots. With the foliar applications, N concentration tended to increase in the permanent organs but not P and K, whereas soluble sugars and starch notably increased in shoot, trunk, or fine root regardless of the different applications. Results indicated that the foliar applications could partially help to restore fruit quality and carbohydrate accumulations in the defoliated trees.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.3
• /
• pp.470-478
• /
• 1997

Background : Phagocytosis is probably the first step for mycobacteria to be virulent in host because virulent strains are more readily phagocytosed by macrophage than attenuated strains. According to the traditional concept, multi-drug resistant strains have been regarded as less virulent. However, this concept has been challenged, since recent studies(reported) showed that the degree of virulence and drug-resistance is not related. The purpose of this study is to evaluate whether the phagocytic activity of M.tuberculosis by peripheral blood mononuclear cells(PBMC) is different according to drug-resistance or host factor. To evaluate this, we estimated the difference of phagocytic activity of drug-resistant and drug-sensitive M.tuberculosis and also estimated the phagocytic activity of PBMC from intractable tuberculosis patients and healthy controls. Methods : PBMC from ten intractable tuberculosis patients and twelve healthy control, and three different strains of heat-killed M.tuberculosis, ie, ADS(all drug sensitive), MDR(multi-drug resistant), and ADR(all drug resistant) were used. After incubation of various strains of M.tuberculosis with PBMC, the phagocytic activity was evaluated by estimating proportion of PBMC which have phagocytosed M.tuberculosis. Results : Drug-resistant strains of M.tuberculosis were phagocytosed easily than drug sensitive strains(Percentage of PBMC phagocytosed M.tuberculosis in healthy control : ADS : $32.3{\pm}2.9%$, ADR : $49.6{\pm}3.4%$, p = 0.0022, Percentage of PBMC phagocytosed M.tuberculosis in intractable tuberculosis patients : ADS : $34.9{\pm}3.6%$, ADR : $50.7{\pm}4.5%$, p = 0.0069). However, there was no difference in phagocytic activity of PBMC from healthy control and intractable tuberculosis patients. Conclusion : Drug-resistant strains of M.tuberculosis were phagocytosed easily than drug sensitive strains and host factors does not seems to influence the phagocytosis of M.tuberculosis.

• Korean Journal of Food Science and Technology
• /
• v.32 no.6
• /
• pp.1278-1284
• /
• 2000

The study was performed to elucidate the effects of ethylene-absorbent on the quality of 'Fuyu' persimmon fruits in the MA package. Five persimmons were packed in a MA package film (low density polyethylene, 0.055 mm film thickness), and stored at $-0.5^{\circ}C$ for 60 days. Two persimmons were repacked in a MA package with or without ethylene absorbent $(1\;M\;KMnO_4+zeolite)$ and stored at $-0.5^{\circ}C$. Ten days later, these packages was moved to $2^{\circ}C$ or $25^{\circ}C$ storage room to examine the effect of the ethylene-absorbent on the quality of the fruits. Ethylene removal by enclosed ethylene absorbent in MA packaging reduced the rate of fruit respiration at $25^{\circ}C$, so that $O_2$ and $CO_2$ concentration in packing were maintained higher and lower, respectively, compared to control. These effects were not observed, however, in $2^{\circ}C$ post-storage. Fruit firmness and sugar composition were also influenced by ethylene absorbent, showing more delayed flesh softening and higher sucrose concentration in ethylene absorbent treated fruits than control. But ethylene-absorbent treatment lowered glucose and fructose concentration. That shows that ethylene could influence on sugar composition by inhibiting sucrose inversion to glucose and fructose. The production of ethanol and acetaldehyde was reduced by ethylene removal, but the effect was not so high as other quality indices.

• Journal of the Korean association of regional geographers
• /
• v.3 no.2
• /
• pp.209-225
• /
• 1997

Today, rapid progress of urbanization is discovered commonly in many countries, especially in developing countries, which has led to spatial order and development process of city. Historically, Taegu was a walled city and formed mono-nucleus which was restricted by the castle. As the city grew gradually, the castle was removed as a result of diversification in traffic network, change of socio-economic environment, formation of industrial base and functional distribution. According to reconstruction maps of residential patterns, there was distinctive residential segregation among ethnic groups. Koreans in Taegu in 1939, aggregated densely in the southern and western parts of the city. The Japanese were concentrated densely in the northern and eastern parts of Taegu. And the street pattern within residential areas of the Korean people was shaped like a maze type in contrast with Japanese residential areas, which showed grid pattern of streets. This is another general pattern of almost all colonial cities, especially in Asia. Through this process, today it appears that, out of overall residential areas which occupy the highest ratio in urban land use, those for eminent people influence the functional development of urban spatial structure very heavily as a key point in urban residetial structure. Truly, residential segregation can be seen as the spatial manifestation of uneven distribution of such important scarce resources as housing and residential environment. In this study, the characteristics of locational distribution of the eminent people show their socially and economically stabilized standing in Taegu, taking the aforesaid situation as a background of the study. And the process of this study is as follows ; to examine the forming process of residential areas in the city as a theoretical supporting, to put in order on classical interpretation to formation of residential areas, and general type modern residential areas formation, and economic decision factor of land use. Therefore, this study aims to examine growth and development of eminent persons' residential areas and, at the same time, extract locational characteristics through the pattern of eminent persons' location and predict changes in the future.

• Korean Journal of Environmental Biology
• /
• v.39 no.2
• /
• pp.184-194
• /
• 2021

Since the construction of a dike in 1983, the water quality in the Bunam Lake has continued to deteriorate due to algal bloom caused by agricultural nutrient loading. Therefore, we evaluated the change in water quality and phytoplankton ecological characteristics in Bunam Lake and Cheonsu Bay, Korea. Water temperature, salinity, dissolved oxygen, chemical oxygen demand (COD), chlorophyll, and phytoplankton community were surveyed in April during the dry season and in July during the rainy reason. As a result, during the dry period, phytoplankton proliferated greatly and stagnated in the Bunam Lake while a very high population of cyanobacteria Oscillatoria spp. (8.61×10⁷ cells L^-1) was recorded. Most of the nutrients, except, nitrate and nitrite, were consumed due to the large growth of phytoplankton. However, during the rainy period, concentrations of ammonia, phosphate, silicate, nitrate, and nitrite, were very high towards the upper station due to the inflow of fresh water. Cyanobacteria Oscillatoria and Microcystis spp. were dominant in the Bunam Lake during the rainy period. Even in the Cheonsu Bay, cyanobacteria dominated due to the effect of discharge and diatoms, such as, Chaetoceros spp. and Eucampia zodiacus, which also proliferated significantly due to increased levels of nutrients. Since the eutrophication index was above 1 in Bunam Lake, it was classified as eutrophic water and the Cheonsu Bay was classified as eutrophic water only during the rainy season. In addition, a stagnant seawater-derived hypoxia water mass was observed at a depth of8m in the Bunam Lake adjacent to the tide embankment and the COD concentration reached 206 mg L^-1 in the bottom layer at B3. Based on this result, it is considered that the water quality will continue to deteriorate if organic matters settle due to continuous inflow of nutrients and growth of organisms while the bottom water mass is stagnant.

• Korean Journal of Environmental Agriculture
• /
• v.32 no.1
• /
• pp.55-60
• /
• 2013

BACKGROUND: The buds of persimmon trees are susceptible to cold damage, often with the late frost, at the time of budburst. This study was conducted to determine effect of the cold damage on shoot and fruit growth the current season. METHODS AND RESULTS: 'Fuyu' trees, grown in 50-L pots, were placed for 1 h at $-2.2{\pm}0.5$, $-2.6{\pm}0.5$, or $-3.0{\pm}0.5^{\circ}C$ within a cold storage, at their budburst on April 5. Some trees under ambient temperature at $10-17^{\circ}C$ served as the control. Cold damage of the buds containing flower buds was 54% at $-2.2^{\circ}C$, and significantly increased to 95% at $-3.0^{\circ}C$. The bud damage included the complete death of all, complete death of main buds only, or the late and deformed shoot growth in the spring. Number of flower buds in early May dramatically decreased as the damage ratio increased. Since the thinning of flower buds in mid-May and fruitlets in early July was done in no or slightly damaged trees, the final number of fruits and yield did not decrease compared with the control when the damage increased by 60% and 70%, respectively. Average fruit weight and skin coloration tended to be better with increasing bud damage. Shoot growth was more vigorous in those trees whose buds were severely damaged by low temperature. CONCLUSION(S): Shoot growth and the yield may depend on the number of flower buds and percent fruit set after the cold damage.