• Journal of Environmental Science International
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• v.19 no.3
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• pp.331-342
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• 2010

Aerosol physical properties have been measured at Pusan National University by using the 16-channel LPC(Laser Particle Counter), and particle characteristics have been examined for the period from Aug. 4 2007 to Dec. 30, 2008. Annual total average, seasonal average, and other averages of the meteorologically classified four categories such as Asian dust, precipitation, foggy, and clear days are respectively described here. Both annually and seasonally averaged number concentration show three peaks at the particle diameter of 0.3, 1.3, and $4{\mu}m$, respectively. However, the first peak for summer season tends to be shifted toward smaller size than other seasons, implying the strong fine particle generation. Meteorological condition shows strong contrast in aerosol concentrations. In Asian dust case, relatively lower number concentrations of fine particles (i.e., smaller than $0.5{\mu}m$) were predominant, while higher concentrations of coarse particles were found particularly for the size bigger than $0.5{\mu}m$. In precipitation day, number concentrations were decreased by approximately 30% due to the removal process of precipitation. Foggy day shows significantly higher concentrations for fine particles, implying the importance of the aerosol condensation process of micro-fine-particle growing to fine-particle. Finally the regressed particle size distribution function was fitted optimally with two log-normal distribution, and discussed the similarities and differences among four categorized cases of the Asian dust, precipitation, foggy, and clear days.

• ALGAE
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• v.21 no.4
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• pp.453-461
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• 2006

This study is intended to clarify the structure and seasonal dynamics of warm tolerant benthic marine algal community in Korea. The species composition and biomass of marine algae at the discharge canal of Wolseong nuclear power plant on the East Coast of Korea were investigated seasonally from February 2001 to October 2005. As a result, 43 species (6 blue-green, 8 green, 9 brown and 20 red algae) of marine algae were found at the discharge canal during the past five years. In general, the number of species observed was abundant during winter to summer and less in autumn. Lyngbya confervoides and Enteromorpha compressa always occurred at the discharge canal during the past five years, and Oscillatoria brevis, Padina arborescens and Caulacanthus ustulatus were common species found more than 80% frequency during the study period. Seasonal fluctuations of mean biomass were 2-659 g dry wt m–2 and dominant species in biomass were Caulacanthus ustulatus (contribution to a total biomass proportion 37%), Enteromorpha compressa (26%) and Padina arborescens (24%). Results showed that, in the floristic composition, the green algae occurred as common algal group at the discharge canal of Wolseong nuclear power plant. In the quantitative aspect, however, the red algae such as Caulacanthus ustulatus and Ahnfeltiopsis flabelliformis appeared as predominant group at the discharge canal, in contrast to Kori nuclear power plant where there was a definite green algal dominance. Differences in algal communities developed at the discharge canals of three nuclear power plants on the East Coast of Korea can probably be related to local environmental factors.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.174-183
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• 2017

The background level and timely variation characteristics of atmospheric $^{222}Rn$ concentrations have been evaluated by the real time monitoring at Gosan site of Jeju Island, Korea, during 2008~2015. The average concentration of atmospheric radon was $2,480mBq\;m^{-3}$ for the study period. The cyclic seasonality of radon was characterized such as winter maximum and summer minimum, consistent with the reduction in terrestrial fetch going to summer. On monthly variations of radon, the mean concentration in October was the highest as $3,041mBq\;m^{-3}$, almost twice as that in July ($1,481mBq\;m^{-3}$). The diurnal radon concentrations increased throughout the nighttime approaching to the maximum ($2,819mBq\;m^{-3}$) at around 7 a.m., and then gradually decreased throughout the daytime by the minimum ($2,069mBq\;m^{-3}$) at around 3 p.m. The diurnal radon cycle in winter showed comparatively small amplitude due to little variability in atmospheric mixing depth, conversely, large amplitude was observed in summer due to relatively a big change in atmospheric mixing depth. The cluster back-trajectories of air masses showed that the high radon events occurred by the predominant continental fetch over through Asia continent, and the radon concentrations from China continent were about 1.9 times higher on the whole than those from the North Pacific Ocean. The concentrations of $PM_{10}$ also increased in proportion to the high radon concentrations, showing a good linear correlation between $PM_{10}$ and radon concentrations.

• Macromolecular Research
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• v.14 no.4
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• pp.466-472
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• 2006

The kinetic behavior of emulsion polymerizations of styrene in the presence of sulfonated N-hydroxy ethyl aniline (SHEA) was investigated with two initiators: 2,2'-azobisisobutyronitrile (AIBN) and potassium persulfate (KPS). SHEA was synthesized using a stepwise polyurethane reaction method from 3-hydroxy-1-propane sulfonic acid sodium salt, isophorone diisocyanate (IPDI), and N-(2-hydroxyethyl) aniline. Stable core-shell poly(styrene/sulfonated N-hydroxy ethyl aniline, St/SHEA) latex particles were successfully prepared by using an appropriate amount of AIBN, in which SHEA plays the role of 'surfmer', i.e., acting as both a surfactant in the emulsion polymerization and a monomer in the chemical oxidative polymerization. The kinetic behavior was dissimilar to that of typical emulsion polymerization systems. A long inhibition period and low rate of polymerization were observed due to radical loss by the oxidative polymerization of SHEA. It was concluded, due to the low water-solubility of AIBN and retardation reaction by SHEA, that the initial loci of polymerization were monomer droplets. However, growing polymer particles as polymerization loci became predominant as polymerization proceeded. It was suggested that AIBN was more effective than KPS in the preparation of the core-shell type poly(St/SHEA) latex particles. With KPS, no substantial polymerization was observed in any of the samples.

• Ocean and Polar Research
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• v.32 no.4
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• pp.351-359
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• 2010

This study examined extensive patches of floating green macroalgal (Ulva prolifera) mats in the northern East China Sea (ECS) using satellite images from mid May through July 2008 and field observation made during early August 2008 cruise. It was previously reported that the massive macroalgal blooms occurred in the coastal areas of Qingdao in China. During our field survey, researchers noticed widely distributed floating patches of macroalgal mats ranging in size from tens of centimeters to a few hundred meters in diameter. Meteorological data in the northern ECS showed high irradiance, high air-temperature, and predominant southerly winds in summer. In the study area during the survey period, surface waters were characterized by the Changjiang Diluted Water (CDW) mass, which contained high concentrations of nitrate and phosphate. The internal transcribed spacer (ITS) sequence of U. prolifera found in the northern ECS was the same as those of U. prolifera sampled from Qingdao blooms, suggesting a possibility that U. prolifera found in two regions would be derived from the same origin. We suggest that U. prolifera in the nearshore Jiangsu Province drifted into the northern ECS and proliferated under favorable meteorological and oceanographic conditions during the summer of 2008.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.450-458
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• 1991

The thermal structures and their spatio-temporal fluctuations in the upper 200m layer off the southeast coast of Korea are studied using the bimonthly temperature data for 17years(1967-1983) at 37 stations. We analyzed the fluctuations of the temperatures in the surface(0-100m) and in the subsurface(100-200m) layers. The fluctuations of temperatures in the surface water are dominated by the annual variation, whereas the subsurface layer temperatures contain considerable non-seasonal fluctuations. The distributions of water temperature anomalies in the subsurface layer are closely related with those in the surface layer. The predominant periods of temperature fluctuations in the subsurface layer, other than the annual variation, are 14 and 70 months. The period of 14 months coincides with that of the pole tide or Chandler wobble. The cluster analysis shows that our study area can be divided into the cold, the frontal and the warm regions.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.3
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• pp.343-355
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• 2005

Cloud/fog water was collected at Daegwallyeong, a typical clean environmental area, by using an active fog sampler during the foggy period in 2002, The pH ranged from 3,7 to 6,5 with a mean of 5,0, but the pH calculated from average concentrations of $H^+$ was 4.4. $SO_4^{2-},\;NO_3^-\;and\;NH_4^+$ were predominant ions with average concentrations of 473,3, 463,3 and $576,0\;{\mu}eq/L$, respectively, This showed that cloud/fog water was slightly acidified, but the concentrations of major pollutants were as high as those for polluted area, suggesting effect from long range transported pollutants, Samples were categorized into four groups (E, W, S, N) by applying 48-h back trajectory analysis using the Hybrid Single-Particle Largrangian Integrated Trajectory (HYSPLIT) model. Concentrations of seasalt $(Na^+\;and\;Cl^-)$ were the highest for group E, indicating large input of seasalts by air masses transported from the East Sea. The concentrations of $SO_4^{2-}$ were slightly higher in group W but the difference was not significant. However, the concentrations of $NO_3^-$ were significantly higher in group W than those in other three groups, The median values of cloud/fog water pH for group N and W were below 4,5, which is significantly lower than median values in group E and group S, This suggests that the acidifying pollutants were transported from the Asia continents and Seoul metropolitan area cause acidification of the cloud/fog water in Daegwallyeong.

• Archives of Plastic Surgery
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• v.40 no.3
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• pp.226-231
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• 2013

Background The reconstruction of volar surface defects is difficult because of the special histologic nature of the tissue involved. The plantar surface is the most homologous in shape and function and could be considered the most ideal of reconstructive options in select cases of volar surface defects. In this paper, we evaluate a single institutional case series of volar tissue defects managed with second toe plantar free flaps. Methods A single-institution retrospective review was performed on 12 cases of reconstruction using a second toe plantar free flap. The mean age was 33 years (range, 9 to 54 years) with a male-to-female ratio of 5-to-1. The predominant mechanism was crush injury (8 cases) followed by amputations (3 cases) and a single case of burn injury. Half of the indications (6 cases) were for soft-tissue defects with the other half for scar contracture. Results All of the flaps survived through the follow-up period. Sensory recovery was related to the time interval between injury and reconstruction-with delayed operations portending worse outcomes. There were no postoperative complications in this series. Conclusions Flexion contracture is the key functional deficit of volar tissue defects. The second toe plantar free flap is the singular flap whose histology most closely matches those of the original volar tissue. In our experience, this flap is the superior reconstructive option within the specific indications dictated by the defect size and location.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.242-247
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• 1992

Twenty strains of pentachlorophnol (PCP) resistant bacteria were isolated from activated sludge of the sewage treatment plant of Jung Lang Chun, Seoul. The predominant strains were Bacillus spp. including B. sphaericus and E. schlegelii. The other strains were identified as Corynebacterium spp., Staphylococcus aureus, Arthrobacter spp. and Aeromonas spp. The resistant strains could be grouped into two categories; PCP-degrading and PCP-adsorbing/absorbing ones. PCP-degrading strains degraded $75{\sim}90%$ of PCP in the medium containing 100 ppm PCP during the first 24 hours of growth. At the initial period the PCP-adsorbing/absorbing strains removed PCP from the medium but started to release PCP after 24 or 72 hours of growth. PCP degradation products from the culture broth of PCP-degrading strains were identified by comparing their $R_f$ values with those of the reference compounds. 2-chlorophenol and 2.4-dichlorophenol were presumed to be the intermediate products of PCP degradation.

• Archives of Plastic Surgery
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• v.41 no.5
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• pp.520-528
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• 2014

Background As the breast cancer incidence has increased, breast-conserving surgery has replaced total mastectomy as the predominant procedure. However, centrally located breast cancers pose significant challenges to successful breast-conserving surgeries. Therefore, we performed partial mastectomy and oncoplastic procedures on centrally located breast cancer as a means of partial breast reconstruction. The authors examined and evaluated the functional and aesthetic usefulness of this reconstruction method. Methods From January 2007 to June 2011, 35 patients with centrally located breast cancers who underwent various oncoplastic procedures based on the breast size and resection volume. The oncoplastic procedures performed included volume displacement surgical techniques such as purse-string suture, linear suture, and reduction mammaplasty. Other oncoplastic procedures included volume replacement procedures with an adipofascial, thoracoepigastric, intercostal artery perforator, thoracodorsal artery perforator, or latissimus dorsi flap. Results Mean patient age was 49 years, and mean follow-up period was 11 months. In cases of small to moderate-sized breasts and resection volumes <50 g, volume displacement procedures were performed. In cases of resection volumes >50 g, volume replacement procedures were performed. In cases of larger breasts and smaller resection volumes, glandular reshaping was performed. Finally, in cases of larger breasts and larger resection volumes, reduction mammaplasty was performed. This reconstruction method also elicits a high patient satisfaction rate with no significant complications. Conclusions In centrally located breast cancer, oncoplastic surgery considering breast size and resection volume is safe and provides appropriate aesthetic outcomes. Therefore, our method is advisable for breast cancer patients who elect to conserve their breasts and retain a natural breast shape.