• Journal of Korean Society of Forest Science
• /
• v.106 no.4
• /
• pp.397-407
• /
• 2017

This research aims to analyze and compare the drought resistance of 7 species of landscape trees commonly grown in Korea. The 7 species are: Camellia japonica, Rhaphiolepis indica, Quercus glauca, Machilus thunbergii, Daphniphyllum macropodum, Dendropanax morbifera and Cinnamomum camphora. In order to analyze their drought resistance, the samples were left without irrigation for 30 days (05/09/2016 ~ 05/10/2016), during which period their respective drought resistor, relative water content, electrolyte elution figures and proline content were measured. As the non-irrigation proceeded, C. camphora was the first to wither, followed by D. morbifera, then D. macropodum, then M. thunbergii, then Q. glauca, then R. indica then finally C. japonica. Of the 7 species, Q. glauca, C. japonica and R. indica can be considered highly drought resistant, since they survived for longer than 3 weeks without irrigation. Relative water content (RWC) plummeted dramatically after the first 15 days of non-irrigation. Whereas RWC readings of C. camphora, D. morbifera, D. macropodum and M. tunbergii dropped by 40% or more, the other 4 species reported a relatively low rate of decrease at 20% or lower. The Camellia japonica, the R. indica and Q. glauca, which were the species with relatively high drought resistance, showed low proline content and electrolyte elution figures, whereas those of C. camphora, D. macropodum, D. morbifera and M. tunbergii were higher. Analysis through the nonlinear regression analysis logistic model showed that non-irrigation proved fatal for the 7 sample species in a range of 22.7 to 37.6 days. The C. japonica, R. indica, Q. glauca and M. tunbergii demonstrated a high drought resistance of 30 days or longer, whereas C. camphora, D. morbifera and D. macropodum had a low resistance of 25 days or less to drought from lack of water. In conclusion, out of the 7 species of broad-leaved evergreen trees tested, C. japonica, R. indica and Q. glauca seem to be suitable for use as landscape trees, owing to their high drought resistance.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.240-240
• /
• 2017

Quinoa (Chenopodium quinoa Willd.) is one of the ancient crops cultivated in the Andes region at an altitude of 3,500-4000m in Chile and Bolivia from 5000 BC. It contains a large amount of protein, minerals and vitamins in comparison with other crops. The cultivation area has been increasing worldwide because of its excellent resistance to various abiotic stress such as salinity, drought and low temperature. ${\gamma}$-Ray radiation of high dose is often used as a tool to induce mutations in plant breeding, but it has a deleterious effect on organisms. However, the radiation may have a positive stimulatory effect of 'hormesis' in the low dose range. This experiment was carried out to investigate the optimum dose range for creating the quinoa genetic resources and to investigate the hormesis effect at low dose on the quinoa. This experiment was performed for 120 days from November, 2016 to February, 2017 in the greenhouse of Gyeongsang National University. ${\gamma}$-Ray radiation was irradiated to seeds at 0 Gy, 50 Gy, 100 Gy, 200 Gy, 300 Gy, 400 Gy, 600 Gy, 800 Gy and 1000 Gy for 8 hours. (50 Gy) using the low level radiation facility ($Co^{60}$) of Cooperative Research Institute of Radiation Research Institute, KAERI. Fifty seeds were placed on each petri dish lined with wet filter paper and germination rate was measured at a time interval of 2 hours for 40 hrs. The length of the root length was measured one week after germination. Each treatment was carried out in 3 replicates. The growth of seedlings were investigated for 10 days after transplanting of 30 day-old seedlings. The plant height, NDVI, SPAD, Fv/Fm, and panicle weight were measured. The germination rate was highest at 50Gy and 0Gy and the rate of seeds treated with 400Gy or higher rate decreased to 25% of the seeds treated with 50Gy. The emergence rate of seedling in pot experiment was higher at the dose of 200 Gy, 300 Gy and 400 Gy than at 0 and 50Gy. However, the rate was lower at strong radiation higher than 600Gy at which $1^{st}$ leaf was not expanded fully and dead due to extreme overgrowth at 44 days after treatment (DAT). The highest value of panicle weight was observed at 50Gy (6.15g) and 100Gy (5.57g). On the other hand, the weight at high irradiated dose of 300Gy and 400Gy was decreased by about 55% compared to low dose (50 Gy). NDVI measurement also showed the highest value at 50 Gy as the growth progressed. SPAD was the highest at 400 Gy and showed positive correlation with irradiation dose except 0 Gy. Fv/Fm was high at 50 Gy up to 30 DAT and no difference between treatments was observed except for 400 Gy from 44 DAT. The plant height was the highest in 50Gy during the growing period and was higher in the order of 50Dy, 100Gy, 0Gy, 200Gy, 300Gy and 400Gy in 88 DAT. In this experiment, the optimal radiation dose for hormesis was 50Gy and 100Gy, and the optimal radiation dose for mutagenesis seems to be 400 Gy.

• Journal of the Korean earth science society
• /
• v.45 no.1
• /
• pp.1-18
• /
• 2024

This study analyzed the effect of warming on PM_2.5 aerosol production in mid-latitude East Asia during June 2020 using PM_2.5 aerosol anomalies, which were identified by incorporating meteorological and climate data into the Weather Research Forecasting model coupled with Chemistry (WRF-Chem) model. The decadal temperature change trend over a 30-year period (1991-2020) in East Asia showed that recent warming has been greater in summer than in winter. Summer warming in East Asia generated low and high pressure in the lower and upper troposphere, respectively, over China. The boundary between the lower tropospheric low and upper tropospheric high pressure sloped along the terrain from the Tibetan Plateau to Korea. The eastern China, Yellow Sea, and Korean regions experienced a convergence of warm and humid southwesterly airflows originating from the East China Sea with the development of a northwesterly Pacific high pressure. In June 2020, the highest temperatures were observed since 1973 in Korea. Meanwhile, enhanced warming in East Asia increased the production of PM_2.5 aerosols that travelled long distances from eastern China to Korea. PM_2.5 anomalies, which were derived solely by inputting meteorological and climatic data (1991-2020) into the WRF-Chem model and excluding emission variations, showed a positive distribution extending from eastern China to South Korea across the Yellow Sea as well as over the Pacific Northwest. Thus, the contribution of warming to PM_2.5 aerosols in East Asia during June 2020 was more than 50%. In particular, PM_2.5 aerosols were transported from eastern China to Korea through the Yellow Sea, where the warm and humid southwesterly airflows implied wet scavenging of sulfate but promoted nitrate production.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.6
• /
• pp.429-433
• /
• 2003

trans-Resveratrol(3,5,4'-trihydroxystilbene) is phenolic compound present in grapes, wines, and peanuts, has been reported to have health benefits including anticarcinogenic effects, protection against cardiovascular diseases and reduced cancer risk. A simple method for the quantitative extraction of trans-resveratrol from peanut has been developed. Optimal conditions for extraction were investigated. Type of solvent, time, and temperature assayed influenced trans-resveratrol yield. Adequate extraction condition was decided to ethanol/water (80:20v/v) maintained at $25^{\circ}C$ for 45 min. After extraction, the protocol consists of sample preparation using a $\textrm{C}_{18}$ solid-phase extraction (SPE) cartridge after concentrate with rotary evaporator and quantified by reversed phase HPLC using a $\textrm{C}_{18}$ column at 308 nm. Analytical methods for measuring trans-resveratrol in peanut were adapted to isolate, identify, and quantify trans-resveratrol in 11 peanut varieties by HPLC (high-performance liquid chromatography) with UV detector, The 11 peanut varieties content ranged from 0.018 to 1.125 $\mu\textrm{g}/\textrm{g}$ with an average of 0.289 $\mu\textrm{g}/\textrm{g}$. The contents were higher in the seeds with than without testa, regardless of varieties. The trans-resveratrol content was Higher in 110, 130 days after sowing than that of other period.

• Korean Journal of Microbiology
• /
• v.51 no.4
• /
• pp.374-381
• /
• 2015

Occurrences of coastal dredged materials are ever increasing due to port construction, navigational course maintenance and dredging of polluted coastal sediments. Ocean dumping of the coastal dredged materials has become virtually prohibited as London Treaty will be enacted as of the year 2012. It will be necessary to treat and recycle the dredged materials that may carry organic pollutants and heavy metals in a reasonable and effective process: collection of the dredged materials, liquid and solid separation, and treatment of organic compounds and heavy metals. In this study we have developed a continuous bioreactor system that can treat a mixture of silt and particulate organic matter using a microbial consortium (BM-S-1). The steady-state operation conditions were: pH (7.4-7.5), temperature ($16^{\circ}C$), DO (7.5-7.9), and salt concentration (3.4-3.7%). The treatment efficiencies of SCOD, T-N and T-P of the mixture were 95-96%, 92-99%, and 79-97%. The system was also effective in removal of heavy metals such as Zn, Ni, and Cr. Levels of MLSS during three months operation period were 11,000-19,000 mg/L. Interestingly, there was little sludge generated during this period of operation. The augmented microbial consortium seemed to be quite active in the removal of the organic component (30%) present in the dredged material in association with indigenous bacteria. The dominant phyla in the treatment processes were Proteobacteria and Bacteroidetes while dominant genii were Marinobacterium, Flaviramulus, Formosa, Alteromonadaceae_uc, Flavobacteriaceae_uc. These results will contribute to a development of a successful bioremediation technology for various coastal and river sediments with a high content of organic matter, inorganic nutrients and heavy metals, leading to a successful reuse of the polluted dredged sediments.

• Korean journal of applied entomology
• /
• v.43 no.4 s.137
• /
• pp.297-304
• /
• 2004

The development of Aphidoletes aphidimyza, an aphidophagous gall midge, was studied at various constant temperatures ranging from 15 to $35^{\circ}C$, with $65{\pm}5\%$ RH, and a photo-period of 16L:8D. When A. aphidimyra was fed either on Aphis gossypii or Myzus persicae, it took 43.9 and 44.5 days, respectively, to develop from egg to pupa at $15^{\circ}C$, whereas at $25^{\circ}C$, 14.3 and 15.8 days. The developmental zero was 10.7 and $10.0^{\circ}C$, respectively, while the effective accumuative temperatures were 210.8 and 245.5 day-degrees. The nonlinear shape of temperature-dependent development, shown by A. aphidimyza when fed on either species of the aphids, was well described by the modified Sharpe and DeMichele model. When distribution model of completion time of development for each growth stage was expressed as physiological age and fitted to the Weibull fuction, the completion time of development gradually shortened from egg to larva, and to pupa. In addition, the coefficient of determination $r^2$ ranged between 0.86-0.93 and 0.85-0.94, respectively providing a good approximation of cumulative developmental rates. The life span of adult was 8.7 and 9.2 days at $15^{\circ}C$, and 3.1 and 2.7 days at $30^{\circ}C$, respectively. Egg incubation period was relatively short at $35^{\circ}C$ but hatchability was less than $50\%$ and the mortality of the larva at $35^{\circ}C$ reached $100\%$. At $30^{\circ}C$, the time of development lengthened and the adult longevity was short suggesting ill effect of high temperatures. Even though the life span of adults at $15^{\circ}C$ was relatively long, none moved freely in the rearing cage and no oviposition occurred. Accordingly, in case A. aphidimyza is adopted to suppress phytophagus aphid populations, it could be applicable to cropping systems with ambient temperatures above $20^{\circ}C$ and below $30^{\circ}C$. Within this range, A. aphidimyza adults was observed to be active and oviposit fully.

• Journal of Sericultural and Entomological Science
• /
• v.50 no.2
• /
• pp.133-139
• /
• 2012

The Aims of this study are to investigate ecological environments and indoor-rearing conditions of Eurema hecabe for artificial rearing. Two different nesting site, a open area nearby small river(A area; Daejin-ri, Gonyang-myeon, Sachun-si, Gyoungsangnam-do) and a foot of a hill area(B area; Noryang-ri, Seolcheon-myeon, Namhae-gun, Kyoungsangnam-do), selected for investigation of ecological habitat environment, and investigated two times per month, during six month, from June to November in 2010. In result, the number of butterflies, Eurema hecabe, at the hill area(B area) was 6 times more than the open area(A area). We observed the number of eggs, larvae and puapae in the B area more times compared to those in the A area. In the B area, Lespedeza cuneata was higher preference than the other host plant, Lespedeza pilosa and Albizia julibrissin. For development of indoor-rearing conditions, common grass yellow butterfly, Eurema hecabe, was reared in a room condition. As a result of oviposition preference experiment, 100-mated-female laid significantly higher number of eggs $104.9{\pm}19.6$ on Lespedeza cuneata plant, whereas the number of eggs was $12.7{\pm}4.5$ on Cassia obtusifolia plant. Moreover, the eggs hatched within $5.1{\pm}0.9$ days from the day of oviposition and procent of egg hatchability was 53.7% on host plant. The headwidth of each developmental larval stage were $0.36{\pm}0.02$(1st), $0.61{\pm}0.02$(2nd), $0.93{\pm}0.05$(3rd), $1.46{\pm}0.08$(4th), $2.25{\pm}0.11$(5th). The larval period was $12.1{\pm}0.9$ days under high temperature, long day condition($25^{\circ}C$, 16L : 8D), showing 81.0% pupal ratio. The pupal period was $6.9{\pm}0.7$ days, and the emergence rate was 79.6%. Based on above experiment, artificial rearing system of common grass yellow butterfly, Eurema hecabe was completed in indoor condition.

• Korean Journal of Heritage: History & Science
• /
• v.40
• /
• pp.357-386
• /
• 2007

At present, thirteen Buddhist bells of Unified Silla are known to the world: Six in Korea, five in Japan and two other bells, and three out of them are impossible to make out its original form. Therefore, we divided the form of Unified Silla Buddhist bells based on the ten other bells, and we tried out to prove the manufacturing technology by the comparison of the research material of Uncheon-dong bell and existing research materials of other bells, in other to find their linkage based on the alloy elemental composition. We divided Unified Silla Buddhist bell into two types: Type I has symmetric apsaras and regular patterns on its face and it was made in early Silla period; type II has asymmetric apsaras and irregular pattern arrangement and made in late Silla period. In particular, Uncheon-dong Buddhist bells is very similar to Komyoji[光明寺] temple bell from ninth century in Japan. It is peculiar that the apsaras on Uncheon-dong bell play vertical music instruments that are never seen in Unified Silla Buddhist bell. Most of Unified Silla Buddhist bell are compounded with Cu-Sn or Cu-Sn-Pb system. From eighth and ninth century, bells were cast with even composition of copper, tin and lead, and the bronze alloy ratio was similar to the record in Gogonggi[考工記], Jurye[周禮], a book from ancient China. Particularly, Uncheon-dong bell is in a rare case of Cu-Sn-Pb-As system. As had been rarely used in Unified Silla Buddhist bells, so we presented the relative research materials. As has the same nature as Pb. Because As easily volatilize at high temperature, it is hard to use. But it has its merit of solidity and durability. Pb enhances fluidity and thereby expresses the patterns more distinct; As makes the bell stronger. The result of lead isotope ratio could not exactly reveal a concrete producing center. However, over the analysis of our samples, hereby we suggest Uncheon-dong bell was made of materials from just one ore deposit.

• Korean Journal of Poultry Science
• /
• v.49 no.4
• /
• pp.255-264
• /
• 2022

This study was performed to investigate the effects of dietary supplementation with ginseng by-products on growth, organ development, blood biochemical profiles, immune response, and stress parameter of broilers reared in high ambient temperatures. One hundred one-day-old male chicks (Ross 308) were used. At week two, the birds were randomly allocated into five dietary groups; control (CON), 0.5% ginseng berry (GB1), 1.0% ginseng berry (GB2), 0.5% ginseng leaves and stems (GLS1), and 1.0% ginseng leaves and stems (GLS2). The temperature was maintained at 32±1℃from 9 AM to 5 PM. Growth, serum immunoglobulins and corticosterone levels were monitored and analyzed. No significant differences among groups were observed in growth. However, during the finisher period (21~35d) and overall period (7~35 d), body weight gain in all supplemented groups tended higher than CON group. Blood biochemical profiles did not significantly differ among treatment groups except in bilirubin level. Serum immunoglobulins and corticosterone level showed no significant differences among groups. IgM and IgG levels were numerically higher in GLS1 than in other groups, but the difference was not significant. Corticosterone level also tended lower in all supplemented groups than in CON group, and larger decreases were observed in groups with higher ginseng by-product concentration. In conclusion, dietary supplementation of ginseng by-products shows potential to reduce heat stress in growing broilers with no negative effect on productivity.

• Korean Journal of Environmental Agriculture
• /
• v.13 no.3
• /
• pp.321-337
• /
• 1994

The garbage from the dwelling houses was composted in two kinds of small composter in laboratory to investigate the possibility of garbage composting. They were general small composters. One (type 1) was insullated but the other (type 2) was not. Because it was found that type 2 was not available for composting under our meteorological conditions through winter experiment, only type 1 was tested in spring and summer. The experiment was performed for 8 weeks in each season. The seasonal variation of several compounds in compost was evaluated and discussed. The result summarized belows are those taken at the end of the experiment, if the time was not specified. 1) The maximum temperature was $58^{\circ}C$ in spring, $57^{\circ}C$ in summer and $41^{\circ}C$ in winter. This temperature was enough to destroy the pathogen except for winter. 2) The mass was reduced to average 62.5% and the volume reduction was avergae 74%. 3) The density was estimated as 0.7kg/l in spring, 0.8kg/l in summer and 1.1kg/l in winter. 4) The water content was not much changed for composting periods. It had 75.6% in spring and 76.6% in summer and winter. 5) There was a great seasonal difference in pH value. It was reached to pH 6.13 in spring, pH 8.62 in summer and pH 4.75 in winter. 6) The faster organic matter was decomposed, the greater ash content was increased. Cellulose and lignin content were increased, but hemicellulose content was reduced during composting period. 7) Nitrogen contents were in the range of 3.1-5.6% and especially high in summer. After ammonium nitrogen contents were increased at the early stage of composting period, they were decreased. The maximum ammonium nitrogen content was 3,243mg/kg after 2 weeks in winter, 6,053mg/kg after 3 weeks in spring and 30,828mg/kg after 6 weeks in summer. C/N-ratios were not much changed. Nitrification occurred actively in spring and summer. 8) The contents of volatile and higher fatty acids were increased in early stage of composting and reduced after that. The maximum content of total fatty acid was 10.1% after 2 weeks in winter, 5.8% after 2 weeks in spring and 15.7% after 4 weeks in summer. 9) The contents of inorganic compounds were not accumulated as composting was proceeded. They were in the range of 0.9-4.4% $P_2O_5$, 1.6-2.9% $K_2O$, 2.4-4.6% CaO and 0.30-0.80% MgO. 10) CN and heavy metal contents did not show any tendency. They were in the range of 0.11-28.99mg/kg CN, 24-166mg/kg Zn, 5-129mg/kg Cu, 0.8-14.3mg/kg Cd, 7-42mg/kg Pb, ND-30mg/kg Cr and $ND-132.16\;{\mu}g/kg$ Hg.