• The korean journal of orthodontics
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• v.20 no.1
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• pp.61-86
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• 1990

To study the effect of prostglandin $E_2$ and evening primrose oil on orthodontic tooth movement in rats, one hundred and sixty rats were divided into four groups of 40 rats each. One group, injected with saline on the palate subperiosteally, served as a control group. A second and third group were injected subperiosteally on the palate with $PGE_2$ $10{\mu}g$ and evening primrose oil 10mg respectively. The fourth group was given indomethacin $20{\mu}g/m{\ell}$ orally by water bottle. The maxillary first molar was moved mesially from the incisors using a 50gm force rubber band. In each group at the 1, 2, 3, 5, and 7th day, 4 rats were examined by light microscope, and 4 by electron microscope. The obtained results were as follows: 1. Osteoclastic activity was maximum at the 3rd day in the $PGE_2$ group on the interradicular alveolar bone of the first molar, followed by the evening primrose oil group, control group, and indomethacin group. 2. Root resorption and vacuolar changes were maximum in the $PGE_2$ group. 3. At the 3rd day of the $PGE_2$ group, the osteoclasts showed well developed ruffled borders and clear zones. At the same day, the evening primrose oil group also showed well developed ruffled borders and clear zones, but less than the $PGE_2$ group. 4. At the 3rd and 5th day of the $PGE_2$ group, fibroblasts showed phagocytized fragmented collagen fibers in the cytoplasm. At the 7th day of the $PGE_2$ group, fibroblasts showed collagen fibers forming at the cell membrane surface.

• Journal of the Korean Society of Tobacco Science
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• v.5 no.2
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• pp.17-24
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• 1983

Varietal difference of crop stand, growth of each organs and the factors of dry matter Production at different growth stage of three local tobacco varieties (Hyangcho, Youngwolyub and Yonginyub) were investigated in 1979 and 1980. Varietal variation of total standing crops was clear from 45th day after transplanting to end maximum value of photosyntheticinon-photosynthetic organs was Hyangcho: 1.9, Youngwolyub; 1.6, Yonginyub; 2.3. Maximum value of L/S and T/R ratio was clear from 35th day after transplanting to 45th day. RGR, NAR and CGR were in decreasing order of Yonginyub) Youngwolyub)Hyangcho through out growth stage, LAR and SLA were in decreasing from early growth stage to last growth stage, LAI was obtained to maximum value in the large growth state and LAI was increasing order of during the total growth period that it was Hyangcho is 7.6. Youngwolyub is 9.1 and Yonginyub is 8.7, SLA was Hyangcho;$2.088\textrm{cm}^2$/g/leaf, Youngwclyub;$2.173\textrm{cm}^2$/g/leaf and Yonginyub;$2.020\textrm{cm}^2$/g/leaf, respectively.

• Molecules and Cells
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• v.22 no.3
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• pp.285-290
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• 2006

The light sensing system in the eye directly affects the circadian oscillator in the mammalian suprachiasmatic nucleus (SCN). To investigate this relationship in the rat, we examined the circadian expression of clock genes in the SCN and eye tissue during a 24 h day/night cycle. In the SCN, rPer1 and rPer2 mRNAs were expressed in a clear circadian rhythm like rCry1 and rCry2 mRNAs, whereas the level of BMAL1 and CLOCK mRNAs decreased during the day and increased during the night with a relatively low amplitude. It seems that the clock genes of the SCN may function in response to a master clock oscillation in the rat. In the eye, the rCry1 and rCry2 were expressed in a circadian rhythm with an increase during subjective day and a decrease during subjective night. However, the expression of Opn4 mRNA did not exhibit a clear circadian pattern, although its expression was higher in daytime than at night. This suggests that cryptochromes located in the eye, rather than melanopsin, are the major photoreceptive system for synchronizing the circadian rhythm of the SCN in the rat.

• Journal of Environmental Impact Assessment
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• v.12 no.4
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• pp.303-313
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• 2003

This study was carried out to survey the high ozone episode of summertime in Busan. The selected day was July 18, 1999 and August 24, 2001 which recorded exceed to 12ppb/hr at 3 station in Busan simultaneously. In case July 18, 1999, thick cloud and variable wind made weak ozone concentration during morning hour. And increase of ozone concentration by revolution of mixed layer for morning hour did not occur in this case study day. Photochemical reaction by strong radiation after 1100LST made sharp increase rate of ozone concentration(50ppb/hr). In case August 24, 2001, the meteorological condition of this day was not general wind with gradient force, very clear day with less cloud amount, high insolation and sunshine. Dongsamdong, Beomcheondong, Daeyeondong, and Sinpyeongdong had double peak which twice maximum concentration in the early afternoon and late afternoon. Ozone concentration of this day was in inverse proportion to Nitrogen oxide strongly. Ozone concentration exceed to 60ppb/hr occurred at 1400LST, continued to 2300LST.

• Journal of Environmental Impact Assessment
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• v.12 no.4
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• pp.281-290
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• 2003

The influence of land-use type on surrounding temperature was studied the relationships between land-use types and the air condition analyzing AWS (Automatic Weather Station) data of Seoul from KMA (Korea Meteorological Administration). The distribution of air temperature by land-use type has been influenced by the different heating and cooling rates. The difference of heating rates depending on the land-use type was largest at 2~3hours after sunrise and the difference of cooling rates was largest from 2hours before sunset to 2hours after sunset with its maximum at sunset. The difference of cooling rates is greatest in a clear and calm weather situation and the large difference in cooling rates between the green areas and built-up area is up to $1.5^{\circ}C/h$. By season, the difference of cooling rates is largest in fall and in turn spring, winter and summer. In a cloudy or rainy day, the difference in heating and cooling rates on land-use type is not distinct but the tendency is similar to a clear day. In all seasons, the rate of difference occurrence of the daily range of temperature between the green areas and built-up area was large, especially fall. In a fall with a clear and calm day, the magnitude of the daily range of temperature between the green areas and built-up area was largest.

• Atmosphere
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• v.15 no.3
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• pp.167-178
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• 2005

Using the FSSP-100(FSSP) and Microwave Radiometer (MWR), the fog and clear day characteristics (the size and number concentration of fog particles and the liquid water content) have been measured and analyzed at Daegwallyoung observation site ($37^{\circ}41^{\prime}N$, $128^{\circ}45^{\prime}E$) during 27 - 30 November 2003 (fog day) and 19 January 2004 (clear day). During the fog days, the measured fog-particle size by using FSSP is 0.8~8.4 ${\mu}m$, which is similar to the WMO typical value, the fog number concentration varies from 121 to 200 count ($No./cm^2$) and the fog liquid water content from $0.018g/m^3-0.1g/m^3$ in the site. The precipitable water vapor obtained by the MWR, showing the correlation coefficient $R^2$=0.83 between the total precipitable water vapor obtained from the radio sonde and MWR, shows the larger amount (0.75-8.3 cm) during the fog days than the clear-sky data (0.2 cm).

• Current Optics and Photonics
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• v.1 no.4
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• pp.263-270
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• 2017

Solar radiation data measured by pyranometers is of fundamental use in various fields. In the field of atmospheric optics, the measurement of solar energy must be precise, and the equipment needs to be maintained frequently. However, there seem to be many errors with the existing type of pyranometer, which is an element of the solar-energy observation apparatus. In particular, the error caused by the thermal dome effect occurs because of the thermal offset generated from a temperature difference between outer dome and inner casing. To resolve the thermal dome effect, intensive observation was conducted using the method and instrument designed by Ji and Tsay. The characteristics of the observed global solar radiation were analyzed by classifying the observation period into clear, cloudy, and rainy cases. For the clear-weather case, the temperature difference between the pyranometer's case and dome was highest, and the thermal dome effect was $0.88MJ\;m^{-2}\;day^{-1}$. Meanwhile, the thermal dome effect in the cloudy case was $0.69MJ\;m^{-2}\;day^{-1}$, because the reduced global solar radiation thus reduced the temperature difference between case and dome. In addition, the rainy case had the smallest temperature difference of $0.21MJ\;m^{-2}\;day^{-1}$. The quantification of this thermal dome effect with respect to the daily accumulated global solar radiation gives calculated errors in the cloudy, rainy, and clear cases of 6.53%, 6.38%, and 5.41% respectively.

• Journal of the Korean Solar Energy Society
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• v.30 no.5
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• pp.100-106
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• 2010

The purpose of this study is to predict the effective sky temperature on Osan City during the summer. The north latitude, east longitude of Osan City is $37^{\circ}06'$ and $127^{\circ}02'$. The altitude from the sea level is 48m. Empirical relations of the effective sky temperature suggested by Duffie and Beckman are compared on clear days. For the effective sky temperature prediction, data measured by the Korea Meteorological Administration is used as an input to the Bliss model. Both Hottel and Krondratyev model are used to calculate the water vapor emissivity. The results using Hottel's model match well with the empirical relation proposed by Bliss. The results show maximum, minimum, and average values depending on water vapor emissivity model. The maximum deviation is about 10K and is due to total emissivity model.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.45-59
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• 2006

In this study, the effects of the surface topographical characteristics on the meteorological fields are examined in a mesoscale meteorlolgical model. We calculated the direct solar radiation using the illumination angle considering the inclination of topography and tried to find out its effect on meteorological fields. In above experiments, we selected two cases for the clear day and the cloudy day to show the effect of weather and represented the results for two cases. In the correction of the direct solar radiation, the results of two cases indicate that there are obvious differences on the steep Taeback and Soback mountains. And on the time-series analysis the east-facing slope of these mountains receives the more direct solar radiation about $10-60W/m^2$ in the morning hours but lesser in the afternoon hours than the horizontal surface while it is opposite on the west-facing slope. And the results mentioned above are more obvious at clear day. With the same analysis method, at clear day, the surface skin temperature is higher at all hours than that on horizontal surface on the both of slope. At cloudy and rainy day, the surface skin temperature on the east-facing slope is higher in the morning hours but lower in the afternoon hours than that on horizontal surface. But on the west-facing slope, it is higher at all hours than that on horizontal surface. In the two cases, the temperature considering the slope of surface is almost higher than that on the horizontal surface. The wind is stronger than that on the horizontal surface with increasing pressure gradient force according as increasing temperature gradient around the Taeback and the Soback mountains.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.90-98
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• 1998

The optimal rechlorination in water distribution systems was investigated by incorporating optimization techniques into a numerical water quality model. For a hypothetical system that consists of 10 junctions including a storage tank and 12 links, the bulk ($k_b$) and pipe-wall ($k_w$) decay-rate constants of chlorine residual are assumed to be 2.0 1/day and 1.5 m/day, respectively. It was also assumed that the lower and upper limits of chlorine residual in the network are 0.2 mg/L and 0.6 mg/L. When the chlorine source is only the storage tank (without rechlorination), the high levels of chlorine residual appear near the storage tank to maintain the chlorine residuals above the lower limit over the junctions. On the other hand, the chlorine residuals in the network are distribute within the desirable range (0.2 - 0.6 mg/L) after the optimal rechlorination through five injection sites including the storage tank. In case of a real water distribution system that comprises 28 junctions including a clear well and 27 links, the bulk and pipe-wall decay-rate constants are 0.3 1/day and 0.2 m/day, respectively. Before rechlorination, the required chlorine residual at the clearwell is 5.1 mg/L to keep the chlorine residuals above the minimum level (0.6 mg/L) over the junctions. By the optimal rechlorination at five injection sites, the chlorine residuals are distributed within a desirable range of 0.6 mg/L through 2.0 mg/L, which can avoid the excess of chlorine residuals near the clear well. Consequently, total chlirine doses are decreased by 81% in the hypothetical distribution network and 69 % in the real distribution network for satisfying the minimum chlorine residuals.