• Journal of Chest Surgery
• /
• v.24 no.12
• /
• pp.1161-1167
• /
• 1991

The study consisted of all patients undergoing surgical repair of isolated secundum type atrial septal defect in patients ages 35 years or older for the period from October 1986 to October 1991. ASD was closed with direct suture in all patients. Response to surgery was excellent. Two patients who had atrial fibrillation was taken low-dose warfarin therapy to prevent stroke. All patients survived operation, and improved by at least one New York Heart Association functional classification. An old age was not a contraindication to surgery.

• Journal of The Korean Astronomical Society
• /
• v.34 no.4
• /
• pp.317-319
• /
• 2001

The response of the earth's magnetosphere to the variation of the solar wind parameters and Interplanetary magnetic field (IMF) has been stud}ed by using a high-resolution, three-dimension magnetohydrodynamic (MHD) simulation when the WIND data of velocity Vx, plasma density, dynamic pressure, By and Bz every 1 minute were used as input. Large electrojet and magnetic storm which occurred on October 21 and 22 are reproduced in the simulation (fig. 1). We have studied the energy transfer and tail reconnect ion in association with geomagnetic storms.

• Publications of The Korean Astronomical Society
• /
• v.21 no.2
• /
• pp.35-42
• /
• 2006

We report a high resolution spectrum of AG Pegasi observed at Bohyunsan Optical Astronomy Observatory (BOAO) on October 2, 2004. Some of permitted emission lines, for example H I, He I, He II, Fe II and Ti II were observed in the spectrum of AG Pegasi in 2004. Lines presented in the longer wavelength region than $6500{\AA}$ are identified. And radial velocities for each element are measured. Then we carefully discuss the geometrical feature of AG Pegasi in October 2004.

• Korean Journal of Medicinal Crop Science
• /
• v.17 no.4
• /
• pp.286-292
• /
• 2009

The aim of this study was to investigate the effect of plant growth at several different growing periods on antioxidant activities and zeatin and ABA contents of Artemisia iwayomogi. Measurements of antioxidant activities, lipid peroxidation inhibition, and superoxide radical scavenging activity were done using PMS, NBT and lipid auto-oxidation analysis, respectively. The results show that activities of antioxidants from Artemisia iwayomogi had much higher than BHT. DPPH free radical scavenging effect of Artemisia leaf extract was increased from $71.06{\pm}4.36%$ in April to $90.06{\pm}4.41%$ in October. Activities of superoxide radical scavenging and lipid peroxidation inhibition were $33.83{\pm}3.45%$ and $45.60{\pm}3.10$ in April and then increased to $84.40{\pm}4.00%$ and $75.86{\pm}3.50%$ in October, respectively. An ELISA technique has been developed for the determination of zeatin and ABA in Artemisia leaves. By this method, the content changes of zeatin and ABA from Artemisia during the growth were investigated. The zeatin content in leaf was measured to be $186.86{\pm}1.40$ pmol/g dry weight in April, however, decreased to $117.93{\pm}5.83$ pmol in October. The ABA content in leaf increased from $19.00{\pm}1.26$ nmol in April to $68.20{\pm}2.52$ nmol in October. Relationship between antioxidant activities and plant hormone contents was indicated that antioxidant activity may depend on decreasing zeatin content or increasing ABA content.

• Korean Journal of Medicinal Crop Science
• /
• v.19 no.6
• /
• pp.435-440
• /
• 2011

This study was conducted to evaluate the quality variation of Lithospermum radix on the pigment contents and antioxidant activities according to different growth stages and areas of cultivation. Acetylshikonin contents showed the tendency to decrease gradually from the middle of July (0.28%) to the end of August (0.05%) and then the content was increased again to the end of October (0.25%). Shikonin content was detected as small amount of about 0.009% during the period. The weight of plants was increased from the end of September to the end of October and showed the highest value as 19.8 g on October 25. ROS scavenging activity was the highest in the early of October as $IC_{50}$ value of 0.11 ${\mu}g/mL$. Lithospermum radix of September showed lower ROS scavenging activities than those of other growth stages as $IC_{50}$ value of 1.02 and 0.49 ${\mu}g/mL$ on September 9 and September 27, respectively. Among 17 areas cultivated Lithospermum radix, 10 areas (59%) showed 0.05-0.10% of acetylshikonin contents and 3 areas (18%) were measured to contain 0.16-0.26% of acetylshikonin.

• Ocean and Polar Research
• /
• v.23 no.3
• /
• pp.245-253
• /
• 2001

To investigate the community structures and the their seasonal variation of phytoplankton and zooplankton, a study was conducted at 6 selected stations during the period from April 1999 to October 2000 in the marine ranching ground off Tongyeong. One hundred ninety species of phytoplankton were identified, including 146 diatoms, 38 dinoflagellates, 4 silicoflagellates and 2 euglenophytes. Phytoplankton standing crops varied extensively by months and stations, ranging from $3.0{\times}10^4\;cells/l\;to\;1.0{\times}10^6\;cells/l.$. The dominant species varied from the vertical distribution as well as seasonal changes. In April and July 1999, Skeletonema costatum and Ceratium fusus were predominant in both the surface and the bottom water columns. Leptocylindrus danicus was the dominant species in April and June 2000, and Thalassiosira spp. were also predominant in bottom waters in June 2000. Pseudonitzschia pungens and Chaetoceros spp. were the dominant species at both surface and near bottom waters in August and October 2000, respectively. Zooplankton abundance was comparatively high in April and July in 1999, and April, June, and October in 2000, but extremely low in November 1999. The density of dominant zooplankton was higher in 2000 than in 1999. Copepods were the most predominant group except for July 1999 when the bivalve larvae showed extremely high abundance. Acartia omorii and Oithona similis were the dominant or subdominant copepod species mainly in April 2000, and June/July, while O. davisae and O. plumifera had peaks in August and October 2000. Corycaeus affinis and Paracalanus sp. also showed higher peaks in April and June (or July), even though they occurred in all sampling time. Centropages abdominalis occurred abundantly only in April 1999. Oikopleura dioica, a gelatinous zooplankton, was another important zooplankton, showing high density in all samples except in July 1999.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.3
• /
• pp.85-90
• /
• 2010

In this study, we have examined the monthly combustion characteristics of Quercus variabilis, a representing Quercus Spp. in Korea, using its living leaves over the period of from June to October. As a result, we were able to identify that their moisture content was about 114%~155%. The leaves of Quercus variabilis collected in October showed the lowest moisture content and nonflaming ignition temperature. The leaves of July showed the fastest flaming ignition time of 27s while those from September showed the longest persistence of flame with 105s, and also showed the highest total heat release amount. There was a noticeable difference in each month of the above period regarding total heat release amount and total smoke release amount with a gradual increase from June to October. The maximum smoke density was a bit higher in October leaves but there was no significant monthly difference. In addition, July leaves were shown to reach the maximum value in the shortest time of 795s.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
• /
• v.22 no.1
• /
• pp.1.2-5
• /
• 1994

Ionospheric sounding experiments have been conducted at RRL (Radio Research Laboratory), Ministry of Communications, using Digisonde 256 since its installation in 1990. Routine observations of the vertical sounding are carried out 48 times (or 39 times) a day, at every 24 hour. In addition, we also made oblique sounding experiments to obtain the real time data of Maximum Usable Frequency (MUF) and detect the anomalous HF propagation, as a part of the joint study between RRL and CRL (Communications Research Laboratory) of Japan. The two stations involved in the study were Anyang (RRL, Korea) and Kokubunji (CRL, Japan). The ionosondes used in both stations were Digisonde 256, developed by ULCAR (University of Lowell, Center for Atmospheric Research), U. S. A. , and the synchronization of time was accomplished with the help of GPS receiver. During most part of the experiments RRL transmitted non-modulated pulses, and CRL received them. The experiment was scheduled from October 25 through October 29, 1993. However, the ionosphere was not developed well enough to conduct the experiment with pre-set operation parameters. The experiment became successful (from 0500 UT to 0800 UT, October 29) only after the operation parameters had been changed, and the continuous ionograms were obtained by CRL at 0718 UT and 0733 UT in October 29, 1993. We believe this type of experiment will ensure the qualitative enhancement of solar-terrestrial physics research and a routine observation of the oblique ionospheric sounding. In this report, we present the results of the fore-mentioned oblique sounding as well as the vertical sounding results obtained by Digisonde 256 at Anyang station of RRL.

• Journal of Environmental Impact Assessment
• /
• v.15 no.2
• /
• pp.121-127
• /
• 2006

The conventional water quality measurements by point sampling provide only site specific temporal water quality information but not the synoptic geographic coverage of water quality distribution. To circumvent these limitations in temporal and spatial measurements, the use of remote sensing is increasingly involved in the water quality monitoring research. In other to assess a trophic state of Yongdam reservoir using satellite imagery data, I obtained Landsat ETM data and water quality data on 16th September and 18th October 2001. The approach involved acquisition of water quality samples from boats at 33 sites on 16th September and 30 sites on 18th October 2001, simultaneous with Landsat-7 satellite overpass. The correlation coefficients between the DN values of the imagery and the concentrations of chlorophyll-a were analyzed. The visible bands(band 1,2,3) and near infrared band(band 4) data of September image showed the correlation coefficient values higher than 0.9. The October image showed the correlation coefficient values about 0.7 due to the atmospheric effect and low variation of chlorophyll-a concentration. Regression models between the chrophyll-a concentration and DN values of the Landsat imagery data have been developed for each image. The regression model was determined based on the spectral characteristics of chlorophyll, so the green band(band 2) and near infrared band(band 4) were selected to generate a trophic state map. The coefficient of determination(R2) of the regression model for 16th September was 0.95 and that of the regression model for 18th October was 0.55. According to the trophic state map made based on Aizaki's TSI and chlorophyll-a concentration, the trophic state of Yongdam reservoir was mostly eutrophic state during this study.

• Development and Reproduction
• /
• v.23 no.4
• /
• pp.323-331
• /
• 2019

In this study, an experiment was conducted to investigate the annual reproductive cycle of a Korean flat bittering, Acheilognathus rhombeus, from Ogok-myeon located in Seomjin River. The reproductive cycle was examined histologically regarding water temperature and day length of the habitat, the gonadosomatic index (GSI), and developmental characteristics of female and male gonads. The maximum GSI was found to be 3.50±0.53 and 1.36±0.14 for females and males, respectively, when the water temperature and day light was 16.9℃ and 11.3 hours, respectively in October 2018. On the other hand, the minimum GSI was found to be 0.16±0.09 and 0.69±0.15 for males and females in December 2018 and February 2019, respectively. The ovipositor of females appeared from August to November 2018. We compared and calculated the stages of germ cell developmental characteristics in the testis and ovaries to determine the reproductive cycle. According to the result, we classified the female A. rhombeus reproductive cycle into four phases, which are ripe and spawning phase (October), degenerative phase (November to December), growing phase (January to March) and mature phase (April to September). The annual reproductive cycle of male A. rhombeus was categorized into four phases: mature phase (June to October), degenerative phase (November to March), resting phase (April) and growing phase (May). The Korean flat bittering is an autumn-spawner as the main spawning season in October. In male, testicular spermatogonia appeared all year-round, and the ripe and releasing phase, which is characteristics of the spawning season in other fish, did not appear.