• Journal of Korean Society for Atmospheric Environment
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• v.31 no.4
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• pp.330-344
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• 2015

Semi-continuous measurements of $PM_{2.5}$ mass, organic and elemental carbon were made for the period of January to October 2014, at six national air monitoring stations in Korea. OC and EC concentrations showed a clear seasonal variation with the highest in winter (January) and the lowest in summer (August). In winter, the high carbonaceous concentrations were likely influenced by increased fuel combustion from residential heating. OC and EC concentrations varied by monitoring stations with 5.9 and $1.7{\mu}g/m^3$ in Joongbu area, 4.2 and $1.2{\mu}g/m^3$ in Honam area, 4.0 and $1.3{\mu}g/m^3$ in Yeongnam area, 3.7 and $1.6{\mu}g/m^3$ in Seoul Metropolitan area, 3.0 and $0.8{\mu}g/m^3$ in Jeju Island, 2.9 and $0.7{\mu}g/m^3$ in Baengnyeong Island respectively. The concentrations of OC and EC comprised 9.6~ 15.5% and 2.4~ 4.7% of $PM_{2.5}$. Urban Joongbu area located adjacent to the intersection of several main roads showed the highest carbon concentration among six national air monitoring station. On the other hand, background Baengnyeong Island showed the lowest carbon concentration and the highest OC/EC ratio (4.5). During the haze episode, OC and EC were enhanced with increase in $PM_{2.5}$ about 1.3~ 3 and 1.3~ 4.0 times respectively. The concentrations of OC, EC in the Asian dust case are about 1~ 2.4 times greater than in the nondust case. The origins of air mass pathways arriving at Seoul, using the backward trajectory analysis, can be mostly classified into 6 groups (Sector I Northern Korea including the sea of Okhotsk, Sector II Northern China including Mongolia, Sector III Southern China, Sector IV South Pacific area, Sector V Japan, Sector VI Southern Korea area). When an air mass originating from northern China and Mongolia, the OC concentrations were the most elevated, with a higher OC/EC ratio (2.4~ 3.3), and accounting for 17% of $PM_{2.5}$ mass on average.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.20-30
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• 1979

The purpose of present study is to analyze the genetic variation of natural stand of Pinus densiflora. In 1976 following after the seletion of 1974 and 1975, twenty trees from each of three natural populations of the species were selected and seeds were collected, and the locations and conditions of populations are presented in table 1, 2 and figure 1. Some morphological traits of the populations were already detailed in our fifth report of this series. The morphological traits of cone, seed and seed-wing, and also the growth performances and needle characters of the seedling were observed in the present study according to the previous methods. The results obtained are summarized as follows; 1. The meteorological data obtained by averaging the records of 30 year period(1931~1960) measured from the nearest meteorological station to each population are shown in fig. 2, 3, 4. The distributional patterns of investigated climate factors are generally considered to be similar among the locations. However, the precipitation density during growing season and the air temperature during dormant season on Samchuk area (Pop. 9) were quite different from those of the other areas. 2. The measurements of fresh cone weight, length, diameter and cone index (i.e.: length to diameter ratio) are presented in table 7. As shown in table 7, all these traits except for cone diameter seem to be not significant in population and to be highly significant in family differences within population. 3. The morohological traits of seed and seed-wing are detailed in table 8, 9, and highly significant differences are recognized among the populations and the families within population in seed weight, seed length, seed thickness but not among the populations in the other observed traits. The values of correlation between the characteristics of cone and seed are presented in table 12. As shown, the correlation between cone length and seed wing length, between seed wing width and seed width were significantly positive in population 8 and 9 but in population 7. The positive correlations between seed length and seed width were calculated in all populations studied 4. Significant statistical differences among populations and families within population are observed in the growth performances of 1-0 seedling height of these progenies. But the differences in 1-1 seedling height and root collar diameter are shown only among familes within population. As shown in table 13, the most parts of correlations are not significant statistically between the growth performances of seedling and the seed characters. 5. As shown in table 15, statistical differences are considered to be significant among the populations in stomata row on both sides of the needle but not in serration density. The correlations between progenies and parents are not generally observed in the investigated traits of needle as shown in table 16.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.228-235
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• 2012

This study was carried out to investigate the effect of irrigation methods for reducing a drainage on the growth and yield in rockwool (Grodan co.) and cocopeat (chip : dust = 50 : 50 included fiber) culture. The nutrient solution was irrigated by $100J{\cdot}cm^{-2}$-100 mL, $50J{\cdot}cm^{-2}$-45 mL, $50J{\cdot}cm^{-2}$-40 mL, $50J{\cdot}cm^{-2}$-35 mL ($100{\sim}50J{\cdot}cm^{-2}$-100~35 mL, Nutrient solution 100~35 mL was irrigated per plant when the accumulated radiation was $100{\sim}50J{\cdot}cm^{-2}$). The drain rates per plant of 100-100, 50-45, 50-40, 50-35 were 26.3%, 8.8%, 6% 4.4% and 23.1%, 7.5%, 5% 3.4% in rockwool and cocopeat slabs. The water contents and EC of 100-100 and 50-45 were managed by the 55~70%, $3.0{\sim}5.0dS{\cdot}m^{-1}$ which were good condition for paprika culture in rockwool and cocopeat slabs, while those of 50-40 and 50-35 were managed by beyond 50%, $4.5{\sim}9.5dS{\cdot}m^{-1}$. The plant height, number of branches and leaf size of 100-100 and 50-45 were similarly increased while those of 50-40 and 50-35 were decreased. The fruit size and weight of 50-40 and 50-35 were small and light, while those of 100-100 and 50-45 were similarly big and heavy. The marketable fruits of 100-100 and 50-45 treatments were similarly more by 9.7~9.8 in rockwool and 8.8~8.9 in cocopeat, while the unmarketable fruits, the small and blossom end rot fruits were increased in 50-40 and 50-35 treatments. The yield of 100-100 and 50-45 treatments were similarly high.

• Radiation Oncology Journal
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• v.33 no.4
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• pp.337-343
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• 2015

Purpose: The purpose of this report is to describe the proton therapy system at Samsung Medical Center (SMC-PTS) including the proton beam generator, irradiation system, patient positioning system, patient position verification system, respiratory gating system, and operating and safety control system, and review the current status of the SMC-PTS. Materials and Methods: The SMC-PTS has a cyclotron (230 MeV) and two treatment rooms: one treatment room is equipped with a multi-purpose nozzle and the other treatment room is equipped with a dedicated pencil beam scanning nozzle. The proton beam generator including the cyclotron and the energy selection system can lower the energy of protons down to 70 MeV from the maximum 230 MeV. Results: The multi-purpose nozzle can deliver both wobbling proton beam and active scanning proton beam, and a multi-leaf collimator has been installed in the downstream of the nozzle. The dedicated scanning nozzle can deliver active scanning proton beam with a helium gas filled pipe minimizing unnecessary interactions with the air in the beam path. The equipment was provided by Sumitomo Heavy Industries Ltd., RayStation from RaySearch Laboratories AB is the selected treatment planning system, and data management will be handled by the MOSAIQ system from Elekta AB. Conclusion: The SMC-PTS located in Seoul, Korea, is scheduled to begin treating cancer patients in 2015.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.3
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• pp.135-152
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• 1975

The following informations are known from physical and chemical characteristics of orchard soils and nutritional diagnosis of orange leaves in Jeju. 1. Most orange orchards are located on terrace and cindercone thus soil moisture and microclimate of an orchard will greatly be affected by its topography. 2. Excessive well drainage, shallow soil depth, high content of gravels, low solid phase ratio and strong wind will give severe problem of soil moisture and wind errosion, thus the exte- nsion of soil depth is necessary for maintain nutrients, water and sufficient root volume. 3. Available soil water was significantly and positively correlated with organic matter content and clay content also contributes to available soil water. Vinyl mulching was greatly helpful for soil water conservation, wind errosion prevention, soil temperature increases during winter. 4. Abundant amphoteric amorphous allophane take a key role to fix phosphorus and also rations and thus it is the major factor to determine fertilizer efficiency. Lime and phosphorus must be applied in deeper soil layer. Release of filed phosphorus must be reevluated for availability. 5. Organic matter such as see weeds will greatly increase fertilizer efficiency and low fertilizer efficiency during spring may be related to available soil water. 6. Nitrogen was in superoptimum and Mg was enough but P and Ca were somewhat deficient according to leaf analysies while K was deficient according to fruit analysis. Phosphorus application increased sugar/acid ratio and potassium decreases rind percentage. 7. Manganese deficiency and toxicity appeared in a few places. Iron and boron were enough. Most places showed tendency of copper excess but some places showed copper deficiency. 8. Soiling after elimination of rock base, application of slow release fertilizer and abundant organic matter, vinyl mulching and drip irrigation will increase fertilizer efficiency greatly and fruit yield drastically.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.679-692
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• 2020

We coupled a CFD model to the WRF-Chem model (WRF-CFD model) and investigated the characteristics of flows and carbon monoxide (CO) distributions in a building-congested district. We validated the simulated results against the measured wind speeds, wind directions, and CO concentrations. The WRF-Chem model simulated the winds from southwesterly to southeasterly, overestimating the measured wind speeds. The statistical validation showed that the WRF-CFD model simulated the measured wind speeds more realistically than the WRF-Chem model. The WRF-Chem model significantly underestimated the measured CO concentrations, and the WRF-CFD model improved the CO concentration prediction. Based on the statistical validation results, the WRF-CFD model improved the performance in predicting the CO concentrations by taking complicatedly distributed buildings and mobiles sources of CO into account. At 04 KST on May 22, there was a downdraft around the AQMS, and airflow with a relatively low CO concentration was advected from the upper layer. Resultantly, the CO concentration was lower at the AQMS than the surrounding area. At 15 KST on May 22, there was an updraft around the AQMS. This resulted in a slightly higher CO concentration than the surroundings. The WRF-CFD model transported CO emitted from the mobile sources to the AQMS measurement altitude, well reproducing the measured CO concentration. At 18 KST on May 22, the WRF-CFD model simulated high CO concentrations because of high CO emission, broad updraft area, and an increase in turbulent diffusion cause by wind-shear increase near the ground.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.1
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• pp.9-16
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• 1978

In order to establish a better combination of nutrients of complex fertilizer for apple tree a boron-enriched complex fertilizer ($N-P_2O_5-K_2O-B_2O_5-MgO$: 10 10-0.2-2.0) was compared with various treatments using urea superphosphate, potash muriate, usual complex fertilizer (22-22-11) and borax in its effect on the various growth status such as total leaf weight per tree and shoot growth of dwarf Fuji (1 year old) and super type Starcreamson (3 year old) grown at comparatively poor soils. For Fuji grown on sandy red soils the boron-enriched complex fertilizer (BC) was best and followed by-usual complex fertilizer NPK only, NPK only+Boron, BC+high boron (17times) and no phosphorus in the order. For Starcreamson grown on heavy clayey soils CB+high boron and phosphorus was best and followed by BC, usual complex fertilizer, NPK only, BC+high boron, NPK+boron and no phosphorus in the order. Without compost in the poor heavy clayey soil the growth was worse with high boron and best with NPK+boron and followed by BC Growth was poor with high boron alone but better with phosphorus and high boron, and it was thought that boron was effective when it was distributed in soil with N.P.K. Fertilizer response of apple tree was well appeared on leaf length, new shoot length and total leaf weight per tree. Suitable formulation of a boron-enriched complex fertilizer for apple tree appeared as 10-20-10-0.6 ($N-P_2O_5-K_2O-B_2O_5$) for poor fields and fields with moderate fertility. Chemical analysis of leaves suggested Mg effect on the increase of leaf weight. Effect of Fe was similar to thatof of Mg.

• Korean Journal of Medicinal Crop Science
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• v.8 no.3
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• pp.234-242
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• 2000

There are two cultivars, 'Jeongsun' and 'Mishima' of Bupleurum falcatum L., a medicinal plant, have been cultivated in Korea. Two cultivars were evaluated and compared in details for major growth characters and their seasonal changes. Jeongsun was higher in stem length and root weight per plant, and earlier in maturity than Mishima, while Mishima was higher in top weight per plant and the ratio of outer phloem layer(OPL) to whole root, and more in branch number. Coefficients of variations of most growth characters were higher in Mishima than in Jeongsun. In relationship between root and shoot growth characters, root weight, root diameter, etc. were positively correlated with stem thickness, top weight, branch number, etc. in both cultivars. In comparison of seasonal changes for growth characters between two cultivars, stem length and node number were almost not increased after September, but root length and branch number tended to increase until November. There were continuous increases of top and root weights in both cultivars after September. Increase rates of top and root weights were higher in Mishima and Jeongsun, respectively. The weight ratio of root part to whole plant in Jeongsun and the ratio of OPL to whole root in Mishima were higher during whole growth stages; especially Mishima showed their continuous increases after October. Jeongsun flowered earlier (August 17) than Mishima (September 16) by one month. Complete flowering date was on August 30 in Jeongsun and on September 30 in Mishima. Basic difference in plant growth between two cultivars was maturity, so shoot growth almost stopped after October in Jeongsun, and continued vegetative growth until November in Mishima with late flowering habit. These results indicate that higher root weight in Jeongsun is due to its earlier flowering character leading to relatively longer time for root growth, as compared with Mishima.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.2
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• pp.117-127
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• 1982

Mulberry plants (Morus alba L.) were grown in pots with the following different nitrogen sources: ammonium sulphate, urea, ammonium nitrate, sodium nitrate + ammonium nitrate ($NO_3:NH_4$=2:1), and sodium nitrate. The effects of the nitrogen sources on mulberry yields, nitrogen recovery, distribution of ions and cation-anion balance (C-A) along leaf sequence and growth stage were investigated. The results were as follows: 1. Leaf yields and nitrogen recovery decreased with increasing $NO_3$-N application rates. 2. Relative cation contents in leaves in the early growth stages showed the following pattern : Na < Mg < Ca < K. However, the order of Ca and K reversed in the later stages. The order of anion contents chifted from $SO_4$ < $NO_3$ < Cl < $H_2PO_4$ in the early stages to $NO_3$ < Cl < $SO_4$ < $H_2PO_4$ in the later stages. 3. Contents of K, $H_2PO_4$, $SO_4$, $NO_3$, T-N and the sum of anion contents (${\sum}A$) were higher in upper leaves whereas Ca, Mg, Cl, the sum of cation contents (${\sum}C$) and (C-A) were higher in lower leaves. 4. When $NO_3$ in leaves decreased, Cl and K as counter-cations increased and consequently Ca decreased. 5. The (C-A) in leaves varied with leaf sequence and growth stage from 700 to 900 me/kg D.M.

• Korean Journal of Veterinary Research
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• v.22 no.2
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• pp.175-185
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• 1982

Since bovine lymphosarcoma causes considerable economic loss to the dairy industry, seroepidemiological survey on bovine leucosis virus (BLV) was carried out for the dairy herds throughout the country to observe the epidemiological situation of the disease by using immunodiffusion test. Attempts were simultaneously made to detect bovine leucosis virus in the lymphocytes from BLV antibody-positive cattle by means of fluorescent antibody techniques, syncytium assay and electron microscopy. In immunodiffusion test for BLV antibody in 2003 heads of dairy cattle selected randomly from 164 herds, the prevalence of positive reactors by regions were 37.8% in Central, 27.2% in Honam (Southwest), 28.0% in Youngnam (Southeast) and 25.2% in Youngdong (East coast)and averaging 29.7%. By provinces, Chungcheong appeared the highest prevalence of BLV antibody carriers (41.8%), while Jeonbug revealed the lowest incidence rate (24.4%). When the results of serological studies were analyzed by age groups and the sizes of herds, the number of reactors increased gradually with the advance in the age of cattle and the herd size. The highest rate of BLV carriers was found in the ages between 6 and 8 years, and in the size of herds with 20 to 50 heads. One hundred and seventeen breeding bulls from the central regions were tested for BLV antibody. Four out of 70 bulls (5.7%) of Korean cattle and 14 out of 39 bulls (35.9%) of Holstein were reactive for BLV antigens. Of 164 dairy herds examined, 17 herds (10.4%) have no BLV antibody-positive cattle, while 42 herds (25.6%) were included in the range of 20 to 40% of the positive rate and 10 herds (6.1%) in the range of over 80% of the rate. When the lymphocytes from the BLV antibody carrying cattle were cultured in the presence of phytohemagglutinin and stained with FITC-conjugated sheep anti-BLV serum, 8 out of 11 cases (72.7%) of BLV positive cattle revealed specific fluorescence for BLV in the lymphocytes. In syncytium assay of the peripheral lymphocytes of the cattle, 5 out of 7 (71.4%) lymphocytes from BLV antibody carriers induced syncytia in the indicators of bovine embryonic splenic cells. The cultured lymphocytes were examined with an electron microscope to detect the BLV particles. Two out of 6 specimens (33.3%) from the reactors showed the typical type C virus with the size of 90 to 110 nm around microvilli and in intracytoplasmic vacuoles.