• Journal of Microbiology
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• v.33 no.3
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• pp.208-214
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• 1995

The effects of various 2, 4-D-degradative plasmids on the axenic growth patterns, the degradation phenotypes, and the competitiveness of different host bacteria were evaluated in liquid cultures; the organisms and plasmids used were Alcaligenes eutrophus JMP134/pJP4, Alcaligenes paradoxus/p2811, Pseudomonas pickettii/p712, pJP4, and p712 or p 2811 exhibited very different restriction fragment profiles in restriction endonuclease digests. These plasmids were transferred to the recipients (P. cepacia and Alcaligenes JMP228) at relatively high frequencies ranging from 8.9 $\times$ 10$^3$ to 1.6 $\times$ 10$^5$ per donar cell. In the axenic liquid cultures the fast-growing strains, such as P. pseudomallei/p745 and P. cepacia/pJP4, exhibited short lag periods, high specific growth rates, and high relative fitness coefficients, while the slow-growing strains, such as P. pickettii/p712 and A. paradoxus/p2811, had long lag periods, low specific growth rates, and low relative fitness coefficients. Depending on the type of plasmid containing the genes for the 2, 4-D pathway, some transconjugants exhibited intermediate grwoth patterns between the fast-growing strains and the slow-growing strains. The plasmid and plasmid-host interactions determined specific growth rate and lag time, respectively, which were shown to be principal determinants of competitiveness among the strains, but relative fitness coefficient derived from the axenic culture was not always predictive for the mixed culture condition.

• Korean Journal of Plant Tissue Culture
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• v.28 no.4
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• pp.209-213
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• 2001

Spathiphyllum floribundum cv. Cupid was micropropagated on LS medium containing various growth regulators. Shoot tips were cultured on media with different concentrations of thidiazuron (TDZ) or banzyladenine (BA). The medium containing 2.0 mg/L BA was most effective on the shoot multiplication and the formation of adventitious multi-shoot cluster from shoot tips among the different concentrations of TDZ and BA. The combined treatments of BA and paclobutrazol (PBZ) were stimulated the shoot multiplication and the formation of adventitious mu]ti-shoot clusters from shoot tips compared to the ones of BA alone. The adventitious multi-shoot clusters were culled with 5∼7 mm in size and cultured on media with BA or thidiazuron (TDZ). Shoot multiplication and shoot cluster proliferation from the shoot clusters were very favorable on media supplemented with 2.0∼3.0 mg/L BA. The shoots grew and rooted out vigorously on media with 2.0∼3.0 mg/L IBA. The rooted plantlets were acclimatized in the soil mixed with a rate of vermiculite 1 and perlite 1, and survived more than 95% in greenhouse.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.174-177
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• 2011

Green manure crops play an important role in organic farming. Field experiment was conducted at paddy soil (fine loamy, mixed, nonacid, mesic family of Aeric Fluvaquentic Endoquepts) in 2008/2009 to 2009/2010 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. This experiment was carried out to evaluate the biomass of hairy vetch (Vicia villosa) and growth of rice (Oryza sativa) by different seeding rates. Seeding rates of hairy vetch consisted of 30, 60, and 90 kg $ha^{-1}$ by broadcasting before rice harvesting. The biomass and nitrogen production of hairy vetch were not significantly different between 60 kg $ha^{-1}$ and 90 kg $ha^{-1}$ of seedinq rates. Also, rice yield was not significantly different between seeding rate 60 kg $ha^{-1}$ of hairy vetch and conventional practice for two years. Therefore, we suggested that seeding rate of hairy vetch should be reduced by continuous cropping and incorporation of hairy vetch under rice-based cropping system.

• Journal of Animal Environmental Science
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• v.9 no.1
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• pp.45-56
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• 2003

$TAO^{TM}$ System is an auto-heated thermophilic aerated digestion process using a proprietary microbe called as a Phototropic Bacteria (PTB). High metabolic activity results in heat generation, which enables to produce a pathogen-free and digested liquid fertilizer at short retention times. TAO$^{TM}$ system has been developed to reduce a manure volume and convert into the liquid fertilizer using swine manure since 1992. About 100 units have been installed and operated in Korean swine farms so far. TAO$^{TM}$ system consists of a reactor vessel and ejector-type aeration pumps and foam removers. The swine slurry manure enters into vessel with PTB and is mixed and aerated. The process is operated at detention times from 2 to 4 days and temperature of 55 to $65^{\circ}C$. Foams are occurred and broken down by foam removers to evaporate water contents. Generally, at least 30% of water content is evaporated, 99% of volatile fatty acids caused an odor are removed and pathogen destruction is excellent with fecal coliform, rotavirus and salmonella below detection limits. The effluent from TAO$^{TM}$ system, called as the "TAO EFFLUX", is screened and has superb properties as a fertilizer. Normally N-P-K contents of screened TAO Efflux are 4.7 g/L, 0.375 g/L and 2.8 g/L respectively. The fertilizer effect of TAO EFFLUX compared to chemical fertilizer has been demonstrated and studied with various crops such as rice, potato, cabbage, pumpkin, green pepper, parsley, cucumber and apple. Generally it has better fertilizer effects and excellent soil fertility improvement effects. Moreover, the TAO EFFLUX is concentrated through membrane technology without fouling problems for a cost saving of long distance transportation and a commercialization (crop nutrient commodity) to a gardening market, for example.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.2
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• pp.139-165
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• 2019

The current status and prospect of decommissioning technology development at KAERI are reviewed here. Specifically, this review focuses on four key technologies: decontamination, remote dismantling, decommissioning waste treatments, and site remediation. The decontamination technologies described are component decontamination and system decontamination. A cutting method and a remote handling method together with a decommissioning simulation are described as remote dismantling technologies. Although there are various types of radioactive waste generated by decommissioning activities, this review focuses on the major types of waste, such as metal waste, concrete waste, and soil waste together with certain special types, such as high-level and high-salt liquid waste, organic mixed waste, and uranium complex waste, which are known to be difficult to treat. Finally, in a site remediation technology review, a measurement and safety evaluation related to site reuse and a site remediation technique are described.

• Korean Journal of Heritage: History & Science
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• v.36
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• pp.69-86
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• 2003

This article introduce the manufacturing technique of Silla potteries based on the result excavated from Songogdong and Mulchunri site in Gyungju. As a result, we selected the kiln-site to produce Silla potteries and knew the feature which following to make them. 1. The Environmental elements to take a kiln-site were abundant fuel, plenty water and suitable soil. In particular, efficient usage of refracted winds and reserved space of forepart in the kiln-site were importantly applied to select place of kiln-site. 2. The structure of the kiln-body have been changing according to the time. It could be massproduced by produce-group from the middle and end of sixth centry which the fireplace-kiln was generalized. 3. The work center of equipments were related kiln-site. It consisted of mixed wheel, keepingpit and ditch. We knew that a look-out shed had been appeared according to utility purpose variously. 4. It sees as trimming trace of inner and outter aspects in excavated potteries and we knew that wheel had been turn to the contrast watch direction. For producing pottery of the good guality, various kiln-tools had been used already at Silla period and they used for the different purpose. 5. We intended to know method for laying the potteries in the kiln through the example of the adherent pottery to be melted. Finally, manufature and tomb-site are separated by the time through current situation of Songokdong and Mulchonri site. At the same time, we could know that group of Chounbuk kiln-site moved from the south to the north step by step.

• Geomechanics and Engineering
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• v.18 no.2
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• pp.179-188
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• 2019

This paper presents an experimental study to evaluate the effect of palm oil on the selected basic physical-chemical and geotechnical properties of kaolin. The experimental findings are further compared with literature outcomes investigating similar properties of fine grained soils subjected to contamination by different types of oils. To this end, palm oil was mixed with oven dried kaolin samples-aiding oil's interaction (coating) with dry particles first, in anticipation to emphasize the effect of oil on the properties of kaolin, which would be difficult to achieve otherwise. Oil content was limited to 40% by dry weight of kaolin, supplemented at intervals of 10% from clean kaolin samples. Observations highlight physical particle-to-particle bonding resulting in the formation of pseudo-silt sized clusters due to palm oil's interaction as evinced in the particle size distribution and SEM micrographs. These clusters, aided by water repellency property of the oil coating the kaolin particles, was analyzed to show notable variations in kaolin's consistency-measured as liquid and plastic limits. Furthermore, results from compaction tests indicates contribution of oil's viscosity on the compaction behavior of kaolin - showing decrease in the maximum dry unit weight (${\gamma}_{d,max}$) and optimum moisture content ($w_{opt}$) values with increasing oil contents, while their decrease rates were directly and inversely proportional in ${\gamma}_{d,max}$ and $w_{opt}$ values with oil contents respectively. Comparative study in similar terms, also validates this lower and higher decrease rates in ${\gamma}_{d,max}$ and $w_{opt}$ values of the fine grained soils respectively, when subjected to contamination by oil with higher viscosity.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.33-40
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• 2020

It is now common to find the wastes buried in the past during the excavation process of soil for large scale housing and land development. Without proper treatment of the wastes environmentally, the excavation process is no longer able to proceed, and an action plan should be provided to treat the wastes with environmental and economic viability. In the study, the relationship between the apparent density of the wastes and the volume conversion factor, which is the basis in the estimation of waste treatment cost was investigated. From 10 sampling points of a landfill site, wastes were sampled, analyzed for physical characteristics, and the apparent density of mixed and sorted waste was assessed. Applying the empirical formula, and the formula we suggested here, the volume conversion factors were compared with that measured directly in the field using dump truck and excavator. Obviously there was a close relationship among the volume conversion factors resulting from the empirical formula, the formula we suggested and that measured in the field.

• Journal of Korean Society on Water Environment
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• v.38 no.2
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• pp.72-81
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• 2022

Numerous studies have investigated the occurrence and fate of microplastics in the environment; however, only limited effort has been devoted to exploring the characteristics of dissolved organic matter (DOM) leached from microplastics. In microplastic (MP)-contaminated environment, MPs are typically mixed with naturally-occurring particles, which interferes with their detection in the environment. Thus, it is necessary to distinguish between the DOM leached from MPs and those leached from natural particles and also to characterize their properties. This study investigated DOM leaching behavior from MPs (polystyrene: PS, polyvinylchloride: PVC) and natural particulates (forest soil: FS, litter leaves: LL) under light, which is considered one of the main weathering processes that affect MPs in the environment. The leached DOM concentrations and fluorescence characteristics were compared under dark versus light conditions. Regardless of the origins, UV light promoted DOM release from all the particulates. More DOM was released from natural particles than from MPs under both conditions. However, the effect of promoting DOM release by UV was more pronounced for MPs than for natural particles. It was observed from fluorescence spectra that the intensity of the humic-like region was substantially reduced when MP-derived DOM was exposed to UV light, whereas the change of intensity was very little for natural particles. Under light conditions, the ratio of protein-like to humic-like fluorescence of MP-derived DOM was higher than that of DOM from natural particles. This study implies that a substantial amount of DOM could be leached from MPs even in MP-polluted environment under UV irradiation. Protein/humic fluorescence ratio could be utilized as a fast probing indicator to separate the two sources of particles under light.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.4
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• pp.255-264
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• 2021

Asian dust (Hwangsa) deposited on the surface of the Korean Peninsula is difficult to recognize their existence in mountainous terrain undergoing active erosion and weathering. This study examined Asian dust sediments mixed in soils by analysing clay mineralogy, mineral composition, and microtextures of fine silt (< 20 ㎛) in the alkali feldspar granite area of Seoraksan. The fine silt was composed of detrital particles derived from bedrocks, Asian dust sediments, and their weathering products. Clay minerals of 2:1 structural type, chlorite, amphibole, epidote, and Ca-bearing plagioclase were identified as eolian mineral particles. During the weathering of the bedrock composed of quartz and alkali feldspars, albite was partially weathered to produce small amounts of gibbsite and kaolin minerals. Hydroxy-Al interlayered clay minerals were formed by the exchange and fixation of polynuclear Al cationic species into the interlayers of expandable 2:1 clay minerals dominated by illite-smectite series clay minerals. Contribution of Asian dust to the fine silt of soils was estimated around 70% on the basis of total contents of 2:1 phyllosilicates.