• Korean Journal of Environmental Agriculture
• /
• v.8 no.2
• /
• pp.128-135
• /
• 1989

To find the effects of solar energy into the rice canopy and its balance on the rice plant growth, a Tongil type rice, Raekyeong and a japonica rice, Koganebare were used with four levels of nitrogen fertilizer application, 6, 10, 14, and 18kg $l0a^{-1}$ in Chigugo, Japan. The micrometerosological data, the solar radiation and absorbed solar radiation by the rice plants, and leaf area index on cardinal growth stage of the rice community were measured. The results are as follows : Raekyeong showed increased LAI by increased nitrogen fertilizer application rates, and larger LAI than Koganebear. 1. There was no difference in total dry weight till 20 days after transplanting regardless of nitrogen levels in the same variety, after that, however, Raekyeong showed higher dry matter productions for the same durations than Koganebare. 2. In early growth stage of transplanting rice, reflection ratio of solar radiation above the crop canogy was about 6%, however, it was increased up to 20% by the increased LAI at heading date. 3. In high levels of nitrogen application plots, LAI were increased so that values were decreased. 4. Relationship between the amount of absorbed radiation by plants and its dry matter production was linearly significant. Higher levels of nitrogen application produced higher dry matter in Raekyeong, however, in lower level, the dry matter production pattern was almost similar between both rice cultivars.

• Korean Journal of Environmental Agriculture
• /
• v.12 no.1
• /
• pp.41-49
• /
• 1993

The Study was conducted to develope the low temperature tolerant methane-producing bacteria(LTTB) and to increase the efficiency of anaerobic fermentation for the treatment of agricultural and livestock wastes at low temperature. The samples were collected from muddy soil, water logged sediment, organic layer and anaerobic sludge at three latitudes, $34.8{\sim}37.4\;^{\circ}N(Korea)$, $41.4\;^{\circ}N(USA)$ and $54.5{\sim}56.9\;^{\circ}N(Canada)$. They were used for determination of the methanogenesis rates for isolation and identification of the LTTB. The methanogenesis rate of smaples at low temperature were higher in the cellulose medium than methanol medium. The methanogenesis rate in the samples of subarctic region were $15{\sim}19$ moles/ml during 30 days at low temperature($8\;^{\circ}C$), whereas not detected in the samples of temperate region. The methanogenesis rate in the enrichment culture of subarctic samples were inhibited by the $40\;{\mu}g/ml$ of streptomycin + vancomycin or ampicillin + oleandomycin which were not effect to the methanogens. An inhabitation of high temperature tolerant methane producing bacteria was identified in the samples of temperate region, whereas that of the LTTB growing at $8{\sim}13^{\circ}C$ was identified in the subarctic region.

• Korean Journal of Clinical Laboratory Science
• /
• v.50 no.1
• /
• pp.37-43
• /
• 2018

Chamaecyparis obtusa (CO) has recently been attracting attention because of its beneficial effects on skin allergies, atopic dermatitis, and skin diseases, such as acne and eczema. In the present study, the extract from CO leaf grown in Jangseong gun, Jeollanam-do, Korea was evaluated for its anti-oxidant, anti-inflammatory, and anti-allergic effects in vitro. The total polyphenol content of the CO leaf extract was $25.89{\pm}0.31mg$ gallic acid equivalents (GAE)/g. Gas-chromatography mass-spectrometry (GC-MS) analysis revealed the presence of six compounds in the CO leaf extract: ${\alpha}-terpinene$ (3.03 mg/g), ${\alpha}-terpineol$ (9.48 mg/g), limonene (5.96 mg/g), borneol (59.78 mg/g), myrcene (4.85 mg/g), and sabinene (11.31 mg/g). The $RC_{50}$ values of the CO leaf extract for $H_2O_2$ and ABTS radical were $5.47{\pm}0.13mg/mL$ and $4.00{\pm}0.01mg/mL$, respectively. In addition, the CO leaf extract showed significant inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells and IgE-induced release of ${\beta}-hexosaminidase$ (degranulation) in mast-cell like RBL-2H3 cells. The cell viability assay showed that the CO leaf extract ($100{\sim}800{\mu}g/mL$) did not affect the viability of human normal skin fibroblast CCD-986sk cells significantly. Overall, these results suggest that the CO leaf extract is a potential functional cosmetic ingredient that can exert anti-oxidant, anti-inflammatory, and anti-allergic effects.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.11 no.1
• /
• pp.24-34
• /
• 2008

To mitigate the climate change and global warming, various technologies have been internationally proposed for reducing greenhouse gas emissions. Especially, in recent, carbon dioxide capture and storage (CCS) technology is regarded as one of the most promising emission reduction options that $CO_2$ be captured from major point sources (eg., power plant) and transported for storage into the marine geological structure such as deep sea saline aquifer. The purpose of this paper is to review the latest progress on the development of technologies for $CO_2$ storage in marine geological structure and its perspective in republic of Korea. To develop the technologies for $CO_2$ storage in marine geological structure, we carried out relevant R&D project, which cover the initial survey of potentially suitable marine geological structure fur $CO_2$ storage site and monitoring of the stored $CO_2$ behavior, basic design for $CO_2$ transport and storage process including onshore/offshore plant and assessment of potential environmental risk related to $CO_2$ storage in geological structure in republic of Korea. By using the results of the present researches, we can contribute to understanding not only how commercial scale (about 1 $MtCO_2$) deployment of $CO_2$ storage in the marine geological structure of East Sea, Korea, is realized but also how more reliable and safe CCS is achieved. The present study also suggests that it is possible to reduce environmental cost (about 2 trillion Won per year) with developed technology for $CO_2$ storage in marine geological structure until 2050.

• Journal of Animal Science and Technology
• /
• v.44 no.1
• /
• pp.123-134
• /
• 2002

An experiment was conducted to establish the most suitable ventilation system for the enclosed nursery pig house in Korea, comparing four different ventilation systems ; i) air enters through perforated ceiling and exhausts through chimney (NA), ii) air enters through perforated ceiling and exhausts through side walls (NB), iii) air enters through perforated ducts and exhausts through side walls (NC) and iv) air enters through perforated ducts and exhausts through chimney(ND). The experiment was carried out during winter and summer separately. The experimental pigs were weaned at fourteen days old in winter (December-February) and at twenty one days old in summer (June-August). The main results of the experiment are as follows : A preliminary experiment showed that in the NC system during summer, air can reach all the pig rooms in the house and the air flow rates of the upper, middle (1.2 m height of the room) and low (at the height of pig stature) parts of the room were measured at 7.0-8.08, over 0.5 and over 0.2 m/s, respectively, which flow rates were much higher(p$<$0.05) than those in other system. At the minimum ventilation efficiency during winter, air flow rates of upper, middle and low parts of the room equipped with the NC system were detected at over 1, less than 0.5 and around 0.07 m/s, respectively. It is concluded that the separated ventilation system air-entering through ducts is the most suitable for the ventilation system of the enclosed nursery pig house and the exhausting system through side walls is more efficient for ventilation than the system through roof. Furthermore, to sustain proper temperature and reduce energy waste as well as heat consumption, a future research should be carried out to develop the environmental control system in relation to developing a heat regulator.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.1
• /
• pp.173-185
• /
• 2018

Effects of three different types of dispersions and flow improving additives composed with fatty acid esters, fatty acid metal salts and amide compound on the vulcanization and the mechanical properties properties of rubber compounds of EPDM and carbon black as fillers. were investigated using Mooney viscometer, moving die rheometer, hardness tester, and universal test machine. The aging characteristics of vulcanized EPDM compounds were also investigated. The Mooney viscosity measured at $125^{\circ}C$ showed a tendency to decrease in the order of amide type> metal salt type > ester type additive. Scorch time showed little or no difference with the addition of ester or metal salt type additives, but the amide type additive shortened a scorch time more than one minute. Rheological measurement data obtained at $160^{\circ}C$ showed that the vulcanization time was faster for metal salt type and amide type additive systems. Delta torque values of EPDM compound increased with metal salt type and amide type additives, but slightly decreased with ester type additive. The tensile strength of the EPDM compound was greatly improved when an ester type additive was added, but the amide type or metal salt type additive had no significant effect. The elongation was significantly improved for metal salt type additive, while the rest were not significantly affected. The tear strength of the EPDM compounds increased with the addition of all kinds of additives, and it increased remarkably in the case of metal salt type additive. Hardness of the EPDM compounds was nearly same value regardless of additive types. The thermal aging of the EPDM blend at $100^{\circ}C$ for 24 h showed little change in the case of metal salt type or amide type additive, but the elongation tends to decrease by 10-20% for all EPDM compounds containing additives.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.25 no.4
• /
• pp.241-250
• /
• 1992

This study was covered the amount of food consumed per day as well as methods estimating the daily food consumption per fish of Agrammus agrammus in natural population to understand flow of food organisms among trophic levels in bio-community of the coastal waters, Shinsudo, Samchonpo. The estimating formulas were induced from the mathematical models that representing the diurnal fluctuation of the stomach fullness of the fish. The daily food consumption could be estimated by both feeding rates and gastric evacuation rates, but it was more reasonable method that based on gastric evacuation rates than feeding rates. The daily food consumption in wet weight per fish by gastric evacuation rates were 1.9856g/day, 3.4725g/day, 4.4418g/day, 5.8168g/day, and 7.2113g/day in the order of age groups from 0 to 4. The daily rations as percentage of body weight were $9.35\%,\;6.65\%,\;5.76\%,\;4.72\%\;and\;5.31\%$ in the order of ages. The daily food consumption was proportional to the body weight of fish, but the daily food consumption per specific body weight was reciprocal to the body weight. Annual food consumption in wet weight. per fish by gastric evacuation rates were 529.98g from the age of 0.25 to 1.0, 1,269.28g from the age of 1.0 to 2.0, 1,622.76g from the age of 2.0 to 3.0, 2,125.57g from the age of 3.0 to 4.0, 1,316.09g from the age of 4.0 to 4.5 The amount of food consumed per fish during 4.25 years, from the age of 0.25 to 4.5, was 6,863.68g in wet weight. the relationships between the daily food consumption(Dr) by gastric evacuation rates and the total length(L, cm) or the body weight(W, g) were as follows: $$Dr=0.036L^{1.702}$$ $$Dr=0.254W^{0.664}$$

• Korean Journal of Microbiology
• /
• v.43 no.4
• /
• pp.298-303
• /
• 2007

Antithrombotic activities of water extract of cheongkookjang and cheongkookjang fermented with green tea or mugwort were evaluated on some antithrombosis related activities in vitro and thrombotic death inhibition in vivo. Cheongkookjang made of white soybean (Glycine max) or black small soybean (Rhynchosia nulubilis) showed potent antioxidative activities. Addition of green tea or mugwort during cheongkookjang fermentation increased the antioxidative activity, cheongkookjang with green tea showed more drastic increase compared with cheongkookjang with mugwort. Nitrite scavenging effects of the cheongkookjang extracts were prominent but the addition of green tea or mugwort seldom increased the scavenging effects. All the cheongkookjang extracts showed strong inhibitory activities on platelet aggregation. The inhibitory activities of cheongkookjang were increased considerably by addition of green tea or mugwort even with low concentration. Plasmin unit as fibrinolytic activity was not affected considerably by addition of green tea. Addition of mugwort decreased the activity transiently at low concentration ($0.3{\sim}1.0%$) but increased again slowly at higher concentration ($1{\sim}3%$). In vitro thrombotic death inhibition test, the antithrombotic activity of cheongkookjang made of black small bean with green tea was higher by about 1.5 times compared to that without green tea. As results, cheongkookjang might inhibit antithrombosis not only by fibrinolytic action but also by inhibition of platelet aggregation and antioxidative action. The addition of functional materials such as green tea or mugwort could increase the antithrombotic function, even at low concentration.

• The korean journal of orthodontics
• /
• v.29 no.4 s.75
• /
• pp.483-490
• /
• 1999

Interdental enamel stripping is an usual method for correction of abnormal tooth shape and tooth size discrepancy which is one of the etiologic factors of malocclusion. Clinically it Is useful to correct the minor crowding in anterior teeth and posterior occlusion during finishing stage of orthodontic treatment. But this procedure has risks such as irreversible tooth reduction and remaining roughness of enamel surface can accumulate plaque which can evoke periodontal problem. Even if various methods were introduced to minimize the enamel surface roughness, their evaluation was limited in morphologic differences by scanning electronic microscope(SEM). The purpose of this study was to compare the various interdental enamel stripping method by SEM and to quantify the difference of surface roughness by use of Surfcorder SEF-30D(Kosaka Lab. Ltd.) which can measure the roughness of surface. The stripping methods were divided into mechanical and mechanical-chemical method. Air-rotor stripping and separating strip were used for mechanical stripping and $37\%$ phosphoric acid was used for chemical stripping. The enamel surface roughness after mechanical or mechanical-chemical stripping of interproximal surfaces of premolars which were extracted for orthodontic purpose were measured and compared by means of SEM and $Surfcorder^{\circledR}$, the results were as follows. 1. Enamel surface of primary treated by coarse diamond bur and separating strip groups showed highest value of roughness. 2. To compare the primary treated groups between mechanical and mechanical-chemical method, the latter group showed lower value of roughness remarkably. 3. Mechanical stripping groups which were treated both coarse and fine instrument showed lower value of roughness as much as non treated group. 4. The use of Pumice for final polishing did not show significantly smoothening the stripped enamel surface any more.

• Journal of Korean Society of Forest Science
• /
• v.40 no.1
• /
• pp.1-18
• /
• 1978

Three Pinus densiflora populations as shown in location map (Fig. 1) were studied in 1977. These succeed the population numbers 10, 11 and 12 after the preceeding populations. Following the previous study methods, 20 trees were chosen from each population and the morphological characteristics such as tree forms, branching habit, needle and wood properties were investigated. The results are summerized as follows; 1. The mean stand ages were ranged from 40 to 45. The growth performances of trees of population 10 and 11 was similar, but 12 seemed to be inferior more or less. 2. The ratios of clear bole length was 0.53 in population 12 as the highest but 0.43 for population 10 as the lowest. 3. The population 12 was considered to be a stand of the coarser branching habit having the crown index (The maximum crown diameter/the crown length) 1.65 though the mean branching angle indicates almost horizontal. 4. The differences were observed in the clear bole length ratios and crown-indices between populations as shown in Fig. 3 and 4. 5. No inter-population differences in serration density of needle was shown but significant inter and intra-population and individual differences (within population) in number of stomata rows and resin duct. 6. Population 12 shown 0.119 of resin duct index as the maximum. 7. The pattern of diameter growth, analyses based on the width of 10-year-ring segment unit (for example, the 1st segment denotes the width between pith center and 10th year ring and the 2nd one is from 11th to 20th year ring and so on.), was alike among populations as shown in Fig. 9. 8. No significant differences between population in mean summer wood percentages as well as in wood specific gravity was observed. The values of wood specific gravity were increased with the increase of ages in population 10 and 11 however vice versa in population 12. 9. The fiber length was increased with the increase of age but no differences between populations as shown in Fig. 12.