• Journal of the Korean earth science society
• /
• v.43 no.2
• /
• pp.303-311
• /
• 2022

Gadolinium, commonly used as a contrast agent for magnetic resonance imaging (MRI), is discharged into aquatic environments without removal after treatment in wastewater treatment plants (WWTPs) because of its high stability. In this study, we collected water samples from Suyeong WWTP, Busan, to investigate the dissolved rare earth element (REE) removal capacity of each wastewater treatment process and to evaluate the discharge of anthropogenic Gd (Gd_anth) from effluents. As wastewater passed through each stage of treatment, the concentrations of light REEs (La-Eu) decreased, whereas those of heavy REEs (Tb-Lu) were relatively consistent. Negative Sm anomalies (<1) were observed in several samples, indicating that Sm can be removed by adsorption onto particles or phosphate during the biological removal process. Positive Gd anomalies (149±50, n=9) were observed in all samples. The ratios of Gd_anth concentrations to measured Gd concentrations in all wastewater treatment processes were higher than 97%. This indicates that Gd_anth was discharged to the Suyeong River without removal during the wastewater treatment process. Considering the daily treatment capacity in each process, the total flux of Gd_anth was estimated to be 259 mmol/day. Our results suggest that mid- and/or long-term monitoring of Gd is needed because Gd_anth is continuously discharged into Suyeong Bay through WWTPs.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.14 no.4
• /
• pp.196-206
• /
• 2012

Studies of seasonal changes in $C_3/C_4$ mixed communities are rare, particularly in Asian summer monsoon climate zones. In our present study, seasonal changes in the profile and coverage of $C_3$ and $C_4$ plants were investigated in 2009 in Haenam, Yeongdong and Cheorwon regions of South Korea (all at different latitudes). The aim was to estimate the impacts of temperature and sunshine duration on species composition and transition timing of the $C_3$ and $C_4$ plants. From our results, the number of $C_3$ plants was found to increase from early spring to mid-May, and then decrease again until September in the Haenam and Yeongdong regions, but continuously increase from early spring to September in the Cheorwon region under relatively low summer temperatures. On the other hand, the number of $C_4$ plants increased from June or July to September in all three regions. These seasonal changes in species number and ratio have a direct impact upon species diversity which is highest when there are no dominant species. The relative coverage and relative summed dominance ratio (SDR') of the $C_3$ plants decreased from spring to autumn, but increased for the $C_4$ plants during this time in an exponential fashion with increasing accumulated temperature and sunshine duration. The transition timing from $C_3$ to $C_4$ plants occurred when the sum of sunshine duration for the days with daily mean temperature above $5^{\circ}C$ was 1017 hrs for the SDR'.

• Journal of Plant Biotechnology
• /
• v.6 no.1
• /
• pp.25-37
• /
• 2004

Successful genetic transformation of plants requires non-chimeric selection of transformed tissues and their subsequent regeneration. With rare exceptions, most transformation protocols still rely heavily on antibiotics for selecting transgenic cells that contain an antibiotic-degrading selectable marker gene. Here, the morphogenic capacity of in-vitro explants of chrysanthemnum and tobacco stems and leaves (control and transgenic) changed with the addition of aminoglycoside antibiotics (AAs), In a test of 6 AAs, phytotoxicity occurred at concentrations of 10 to 25 and 50 to 100$\mu\textrm{g}$ $mL^{-1}$ in chrysanthemum and tobacco explants, respectively. Light conditions as well as explant source and size also had significant effects. The use of transverse thin cell layers (tTCLs), in conjunction with high initial AA selection levels, supported the greatest regeneration of transgenic material (adventitious shoots or callus) and the lowest number of escapes. Flow-cytometric analyses revealed no endodu-plication in chrysanthemum, even at high AA levels. However, this phenomenon was observed in tobacco calli(8C or more), even at low AA concentrations (i.e., 5 to 10 $\mu\textrm{g}$ mL$^{-1}$ ).

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.11
• /
• pp.121-126
• /
• 1972

Regim-8(TIBA), a Chemical pinching agent, was applied to soybean plants of 6 varieties at 6 leaf stage in oder to develop a chemical pruning method. The results are summarized as follows: 1) The more inhibition in plant height and rare lodging were abserved at 2, 000ppm level of treatment (50cc of Regim-8 diluted in 100ι of water). 2) Number of branches and grains per plant were increased by Regim-8 treatment, while number of main stem nodes were decreased. 3) It appeared that photosynthetic efficiency of the soybean plant community treated by Regin-8 were improved. This increased number of pod per plant and hence soybean yield increased by applying Regim-8. 4) Antilodging effects of Regim-8 were also appeared to result in better filling of pods and higher yield per unit area.

• Journal of Environmental Science International
• /
• v.15 no.12
• /
• pp.1103-1107
• /
• 2006

Iris odesanensis Y.N. Lee is one kind of species among 54 endangered plant species designated by the Ministry of Environment in Korea. It is very rare native plant throughout the country. Therefore, this study was conducted to investigate the native Iris odesanensis in Mt. Naeyon for their distribution and ecological characteristics. They were mostly distributed mid-slope of the mountain from 443m to 498m altitude. They were located lower part of valley and provided enough humid condition. They had proper light and humidity conditions as they faced south south west, south south east, and south. They were also located at the places deciduous woody plants were distributed for proper light conditions for spring blooming. Iris flowered to use light at the period before the trees thickly covered with foliage. However this unfavorable light condition caused low percentage as 7.04% of blooming individuals in this study. In herbaceous, Vioia chaerophylloides(Regel) W. Hocker, Carex siderosticta Hance, Erythronium japonicum Decne., Oxalis obtriangulata Max., Hepatica asiatica Nakai, Lilium tsingtauense Gilg et cetera were appeared well. We propose that proper pruning of upper branches of the deciduous trees is needed for suitable light condition of management of native sites.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.1 no.1
• /
• pp.5-16
• /
• 1999

The purpose of this study is to identify the distinctive characterics HYBRID, strictly defined, an offspring that is a cross between different species, genera, or, in rare cases, families, More loosely defined, a hybrid can also be a cross between parents of different subspecies or varieties of a species. Hybrid varieties of plants and animals are of economic value because the hybrid is nearly always more vigorous, larger, and more fertile than either of its parents. Plant and animal hybrids may arise spontaneously in nature or may be produced intentionally by man. Forward-looking fashion explores progress. Adjusting to a world that has integrated genetics and its mutations, the new silhouette seems without references, as if born from a spontaneous generation. A slightly bizarre composite, asymmetrical, discreetly technological aesthetic, it draws on the latest technological details. the pursuit of performance and ergonomics, yet also of comfort and amusement that takes into account the body and its articulations, generates strange garments. Inspired by medical protheses. Focos on fabric touches, their weightiness and surface effects obtained with silicone, rubber or wax. in a range that highlights yellows but can also contrast with colder, slightly surgical hues, the hybrid woman doesn't necessarily want to stand out.

• Korean Journal of Plant Resources
• /
• v.23 no.6
• /
• pp.550-553
• /
• 2010

The representative research institutes in North Korea are the Academy of Science and the laboratories of major universities. The National Academy of Science consists of headquarters, Academy of Medicinal Science, Academy of Forestry Science, and Academy of Agricultural Science. Under the authority of the National Academy of Science, Central Information Agency for Science and Technology (CIAST) has built up a database system integrating all the science technology data to provide scientific and technological information. The major universities of North Korea include Kim Il-sung University, Kim Chaek University of Technology, Pyongyang Agricultural College, and Wonsan Agricultural College, and an agricultural college is situated in each province. Out of 3,860 plant species in North Korea, 158 species which amounts to approximately 4% of the total are rare and endangered, and deforestation is under a critical situation. The Oriental Medicine (Koryo Medicine) has been well developed using medicinal plants, and practical researches on biotic pesticide are largely conducted as an alternative to tackle the shortage of farming materials. Hereafter, a South-North joint research on the amount of plant resources and the methods of its conservation is needed and the North Korean research areas of biotic pesticide are worth adopting to the South Korean eco-friendly organic agriculture.

• Corrosion Science and Technology
• /
• v.2 no.4
• /
• pp.178-182
• /
• 2003

Slow Strain Rate Tests (SSRT) were carried out to investigate the effect of environmental factors on the Stress Corrosion Cracking (SCC) susceptibility of 3.5NiCrMoV steels used in discs for Low-Pressure (LP) steam turbines in electric power generating plants. The influences of dissolved oxygen on the stress corrosion cracking of turbine steel were studied, For this purpose, specimens were strained at variously oxygenated conditions at $150^{\circ}C$ in pure water. When the specimen was strained with $1{\times}10^{-7}s^{-1}$ at $150^{\circ}C$ in pure water, increasing concentration of dissolved oxygen decreased the elongation and the UTS. The corrosion potential and the corrosion rare increased as the amounts of dissolved oxygen increased. The increase of the SCC susceptibility of the turbine steel in a highly dissolved oxygen environment is due to the non protectiveness of the oxide layer on the turbine steel surface and the increase of the corrosion current. These results clearly indicate that oxygen concentration increases Stress Corrosion Cracking susceptibility in turbine steel at $150^{\circ}C$.

• Nuclear Engineering and Technology
• /
• v.49 no.2
• /
• pp.327-334
• /
• 2017

Common-cause failure (CCF) events can significantly impact the availability of safety systems of nuclear power plants. For this reason, the International Common Cause Data Exchange (ICDE) project was initiated by several countries in 1994. Since 1997 it has been operated within the Organisation for Economic Co-operation and Development (OECD)/Nuclear Energy Agency (NEA) framework and has successfully been operated over six consecutive terms (the current term being 2015-2017). The ICDE project allows multiple countries to collaborate and exchange CCF data to enhance the quality of risk analyses, which include CCF modeling. As CCF events are typically rare, most countries do not experience enough CCF events to perform meaningful analyses. Data combined from several countries, however, have yielded sufficient data for more rigorous analyses. The ICDE project has meanwhile published 11 reports on the collection and analysis of CCF events of specific component types (centrifugal pumps, emergency diesel generators, motor operated valves, safety and relief valves, check valves, circuit breakers, level measurement, control rod drive assemblies, and heat exchangers) and two topical reports. This paper presents recent activities and lessons learnt from the data collection and the results of topical analysis on emergency diesel generator CCF impacting entire exposed population.

• Journal of Plant Biotechnology
• /
• v.40 no.1
• /
• pp.43-48
• /
• 2013

Oreorchis coreana Finet is threatened globally by over-collection from its natural habitats for horticultural purposes. Its rarity in nature makes this plant one of the most endangered species in Korea. In this study, we investigated the effects of sodium hypochlorite (NaOCl) on orchid seed viability and seed germination. An in vitro bioassay swelling test using immature seeds was compared with a standard chemical procedure using triphenyl tetrazolium chloride (TTC) to test seed viability. In general, the bioassay was more appropriate for estimating embryo viability after a prolonged pre-treatment (more than 1 h) in 1% NaOCl, a surface sterilant often used to enhance germination of seeds of terrestrial plants. Therefore, an efficient method for investigating in vitro swelling of immature seeds is urgently needed. We established a method for determining the viability and swelling of O. coreana seeds via in vitro examination of immature seeds. Treatment of immature seeds with 1% NaOCl for 10 min greatly enhanced the extent of swelling of immature zygote embryos when compared to untreated seeds. These data obtained here appear to be comparable to viability and swelling that occurs in O. coreana seeds via asymbiotic germination.